CN1729240A - Flame retardant polyester compositions for calendering - Google Patents

Abstract

A flame-retardant polyester composition suitable for calendering can be prepared from the following: a polyester having a crystallization half-life of at least 5 minutes, a plasticizer, a phosphorus-containing flame retardant miscible with the plasticized polyester, and an additive that effectively prevents the polyester from sticking to the calendering rolls. Also disclosed are methods for producing flame-retardant films or sheets by calendering the composition, as well as the flame-retardant films or sheets produced therefrom. These films and sheets exhibit excellent appearance, flexibility, and flame retardancy, and are useful in a wide range of decorative and packaging applications.

Description

Flame retardant polyester composition for calendering

Cross References to Related Applications

This application claims the benefit of US Provisional Application Serial No. 60/435,584, filed December 20,2002.

technical field

The present invention relates to polyester compositions for calendering, and more particularly to flame retardant polyester compositions for calendering. The present invention further relates to a method of calendering flame retardant polyester compositions for producing flame retardant films or sheets, and to flame retardant polyester films or sheets produced by such calendering methods.

Background technique

Calendering is an economical and efficient means of producing films and sheets from plastics, such as plasticized and rigid polyvinyl chloride, abbreviated herein as "PVC", and polypropylene compositions. Films and sheets typically have a thickness ranging from 2 mils (0.05 mm) to 80 mils (2.0 mm). Calendered PVC film or sheet is easily thermoformed into various shapes that can be used in a large number of applications including: packaging, pond lining, printing technology, event cards, security cards, facings, wall coverings, book binding, documents Laminates, floor tiles and products that are printed, decorated or laminated in secondary processing. Additional discussions on polypropylene resin compositions for use in calendering processes can be found in Japanese Application No. Hei 7-197213 and European Patent Application No. 0744439A1.

In contrast, conventional methods of processing polyester into film or sheet involve extruding a polyester melt through a manifold of a flat die. Manual or automatic die lip adjustments are used to control the thickness of the material web. Water-cooled chill rolls are used to quench the molten web and provide a smooth finished surface. While the extrusion process can produce films and sheets of superior quality, extrusion does not have the throughput and economic advantages of calendering.

Currently, PVC compositions are the largest segment of the calendered film and sheet economy. Small amounts of other thermoplastic polymers, such as thermoplastic rubber, certain polyurethanes, talc-filled polypropylene, acrylonitrile/butadiene/styrene terpolymers (ABS resins), and chlorinated polyethylene, are also sometimes processed by the calendering method . In contrast, polyester polymers such as polyethylene terephthalate, abbreviated herein as "PET", or polybutylene terephthalate, abbreviated herein as "PBT" ", difficult to successfully calender. For example, a PET polymer with an inherent viscosity value of 0.6 dL/g has insufficient melt strength to process properly on calender rolls. Additionally, when polyester is fed into rolls at typical processing temperatures of 160°C to 180°C, the PET polymer will crystallize, resulting in an inhomogeneous mass, which will cause significant forces on the calender stand , so it is not suitable for further processing. Another problem is that polyester polymers have a tendency to hydrolyze during processing, in the molten or semi-molten state, on rolls exposed to atmospheric moisture. Typical PET polymers also have a tendency to stick to the calender rolls at typical processing temperatures. Avoiding these difficulties often requires careful selection of polymer properties, additives and processing conditions. Calendering of various polyester compositions has been described in, for example, U.S. Patent Nos. 5,998,005; 6,068,910; 6,551,688; U.S. Patent Application Serial No. 10/086,905; Japanese Patent Application Nos. 8-283547; 10-363-908; 2000-310710; 2001-331315; 11-158358; and World Patent Application No. 02/28967.

Many current applications of calendered films have stringent flammability requirements. Calendered films made from polyester generally do not have sufficient flame retardancy for use in many industrial applications. In addition, the flame retardants that are often used with various polymer compositions are often not compatible with the molten polyester, reactive with the polyester or its various additives, or do not provide the desired level of flame retardancy at appropriate concentrations sex.

In order to obtain a film or sheet with the desired level of softness, polymeric materials, such as PVC and cellulose esters, must be plasticized prior to calendering. However, most other thermoplastic resins, such as polyesters, polyamides, and polyolefins, generally do not contain plasticizers when processed in the molten state into rigid molded or extruded objects. Plasticizers increase the flexibility and softness of calendered polyester films, improve polyester processing, and help prevent polyester from sticking to calender rolls. However, the addition of plasticizers generally increases the combustible species, resulting in increased flammability. The increased flammability of plasticized polyesters has created a need for flame retardant plasticized polyester compositions suitable for the production of films and sheets by calendering (as a more economical alternative to the extrusion process).

Contents of the invention

We have found that flame retardant polyester compositions suitable for calendering can be prepared from a polyester having a crystallization half-life of at least 5 minutes, a plasticizer, a flame retardant that is miscible with the plasticized polyester, and a release additive . Accordingly, the present invention provides a flame retardant polyester composition for calendering comprising:

(a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is a random copolymer;

(b) plasticizers;

(c) phosphorus-containing flame retardants that are miscible with polyesters plasticized with plasticizers; and

(d) Additives effective in preventing polyester from sticking to calender rolls.

The polyester composition comprises polyester (which is a random copolymer), an additive to prevent the polyester from sticking to calendering rolls, and a plasticizer that provides flexibility, softness, and support for the production of polyester film by calendering. Especially suitable processing properties for sheet materials. The polyester compositions are also flame retardant, making films and sheets produced therefrom particularly desirable for industrial applications.

Another embodiment of the present invention is a flame retardant polyester composition for calendering comprising:

(a) 50 to 95 percent by weight of a polyester having a melting temperature below 220°C and having a crystallinity of more than 1% after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization, wherein the polyester is atactic copolymer;

(b) 5 to 50% by weight, based on the total weight of the polyester composition, of a plasticizer that is miscible with the polyester; and

(c) Phosphorus-containing flame retardants which are miscible with polyester plasticized with a plasticizer.

For the latter composition, the presence of additives to prevent the polyester from sticking to the calender rolls is optional. Furthermore, the present invention provides a method for producing a flame-retardant film or sheet by calendering the above composition, and a flame-retardant film or sheet produced therefrom. These films and sheets have excellent appearance, flexibility, and flame retardancy, and can be used in a wide variety of decorative and packaging applications. The films and sheets are readily thermoformable into specific shapes for both food and non-food packaging applications. They can be printed with a wide variety of inks and can be laminated to fabric or other plastic films or sheets either on-line or off-line. Some specific end uses include printing technology, event cards, security cards, facings, wall coverings, book bindings, folders, and more.

Detailed description

The flame retardant polyester composition can be calendered using common calendering methods to produce flame retardant films and sheets. Accordingly, in a general embodiment, the present invention provides a flame retardant polyester composition for calendering comprising: a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is free of a plasticizer; a phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer; and an additive that is effective in preventing the polyester from sticking to calender rolls. The present invention further provides a method for manufacturing a flame-retardant film or sheet and the film and sheet prepared by the method. Calendered films and sheets typically have a thickness in the range of 2 mil (0.05 mm) to 80 mil (2 mm).

Unless indicated to the contrary, numerical parameters set forth in the following specification and appended claims should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Furthermore, ranges mentioned in the specification and claims are expressly intended to include the entire range and not just the endpoints. For example, a range described as 0 to 10 is used to disclose all integers between 0 and 10, such as 1, 2, 3, 4, etc., all fractions between 0 and 10, such as 1.5, 2.3, 4.57, 6.1113 and so on, and endpoints 0 and 10. Furthermore, ranges relating to chemical substituent groups, such as "C ₁ to C ₅ hydrocarbons", are intended to specifically include and disclose C ₁ and C ₅ hydrocarbons, as well as C ₂ , C ₃ and C ₄ hydrocarbons.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing methods.

The term "polyester" as used herein is intended to include "copolyesters" and is understood to mean synthetic polyesters prepared by polycondensation of one or more difunctional carboxylic acids with one or more difunctional hydroxyl compounds. polymer. Typically the difunctional carboxylic acids are dicarboxylic acids and the difunctional hydroxy compounds are diols such as glycols and diols. Alternatively, the difunctional carboxylic acid may be a hydroxycarboxylic acid, such as p-hydroxybenzoic acid, and the difunctional hydroxy compound may be an aromatic core bearing 2 hydroxyl substituents, such as hydroquinone. The term "residue" as used herein refers to any organic structure introduced into a polymer or plasticizer by polycondensation of the corresponding monomers. Thus, the dicarboxylic acid residues may be derived from dicarboxylic acid monomers or their related acid halides, esters, salts, anhydrides or mixtures thereof. Accordingly, the term dicarboxylic acid as used herein is intended to include dicarboxylic acids and any derivatives of dicarboxylic acids, including their related acid halides, which can be used in the polycondensation process with diols for the manufacture of high molecular weight polyesters. , esters, half-esters, salts, half-salts, anhydrides, mixed anhydrides or mixtures thereof.

The flame retardant polyester composition of the present invention is prepared from a polyester comprising dicarboxylic acid residues, diol residues and repeating units. As used herein, "repeating unit" refers to an organic structure having dicarboxylic acid and diol residues bonded through a carbonyloxy group. The polyesters of the present invention comprise substantially equimolar proportions of acid residues (100 mole %) and diol residues (100 mole %) which react in substantially equal proportions such that the total moles of repeating units equals 100 moles %. Thus, the mole percentages provided in this specification may be based on the total moles of acid residues, the total moles of diol residues, or the total moles of repeating units. For example, a polyester containing 30 mole percent isophthalic acid based on total acid residues means that for a total of 100 mole percent acid residues, the polyester contains 30 mole percent isophthalic acid. Thus, there are 30 moles of isophthalic acid for every 100 moles of acid residues. In another example, a polyester comprising 30 mole % ethylene glycol based on total diol residues means that the polyester comprises 30 mole % ethylene glycol for a total of 100 mole % diol residues. Thus, there are 30 moles of ethylene glycol per 100 moles of diol residues. In a third example, a polyester comprising 30 mole percent of a monomer, which may be a dicarboxylic acid, a diol, or a hydroxycarboxylic acid, based on the total number of repeat units, refers to the polyester for a total of 100 mole percent of repeat units. Contains 30 mol% of this monomer. Thus, there are 30 moles of this monomer residue per 100 moles of repeating units.

The polyesters of the present invention have a crystallization half-life from the molten state of at least 5 minutes. The crystallization half-life may for example be greater than 7 minutes, greater than 10 minutes, greater than 12 minutes, greater than 20 minutes, greater than 100 minutes and greater than 300 minutes. Typically, polyesters having a crystallization half-life of at least 5 minutes are copolyesters or random copolymers. The term "random copolymer" as used herein means that the polyester comprises more than one diol and/or diacid residue, wherein the different diol or diacid residues are randomly distributed along the polymer chain. Accordingly, the polyesters of the present invention are not "homopolymers" or "block copolymers". Preferably, the polyester has a substantially amorphous morphology, meaning that the polyester comprises substantially disordered polymer domains. Amorphous or semi-crystalline polymers generally have only a glass transition temperature (abbreviated herein as "Tg"), or a glass transition temperature in addition to their melting point (abbreviated herein as "Tm"), which are measured by well-known methods , such as differential scanning calorimetry ("DSC"). Desired crystallization kinetics from the melt can also be obtained by adding polymer additives, such as plasticizers, or by modifying the molecular weight characteristics of the polymer. The polyesters of the present invention may also be miscible blends of substantially amorphous polyesters with more crystalline polyesters in proportions necessary to give a crystallization half-life of at least 5 minutes. In preferred embodiments, however, the polyesters of the present invention are not blends.

The crystallization half-life of the polyesters used herein can be measured using methods well known to those skilled in the art. For example, crystallization half-life can be measured using a Perkin-Elmer Model DSC-2 Differential Scanning Calorimeter. Crystallization half-life was determined from the molten state using the following procedure: A 15.0 mg polyester sample was sealed in an aluminum pan and heated at a rate of approximately 320°C/minute to 290°C for 2 minutes. The sample was then immediately cooled to predetermine the isothermal crystallization temperature at a rate of approximately 320°C/min in the presence of helium. The isothermal crystallization temperature is the temperature between the glass transition temperature and the melting temperature which gives the highest rate of crystallization. Isothermal crystallization temperatures are described eg in Elias, H. Macromolecules, Plenum Press: NY, 1977, p. 391. The crystallization half-life is determined as the time interval from reaching the isothermal crystallization temperature to the crystallization peak point on the DSC curve.

The polyester may comprise (i) at least 80 mole percent (mol %) residues of diacids comprising one or more of the following: terephthalic acid, naphthalene dicarboxylic acid, 1,4-cyclohexane alkanedicarboxylic acid or isophthalic acid; and (ii) residues of diols comprising 10 to about 100 mole percent of 1,4-cyclohexanedimethanol and 0 to 90 mole percent of a or more diols comprising 2 to 20 carbon atoms, wherein the diacid residues are based on 100 mole percent, and the diol residues are based on 100 mole percent. Any of the various isomers or mixtures of isomers of naphthalene dicarboxylic acid may be used, but the 1,4-, 1,5-, 2,6- and 2,7-isomers are preferred. Furthermore, cycloaliphatic dicarboxylic acids, such as 1,4-cyclohexanedicarboxylic acid, may be present as pure cis or trans isomers or as a mixture of cis and trans isomers. In one embodiment, for example, the polyester may comprise 80 to 100 mole percent diacid residues from terephthalic acid and 0 to 20 mole percent diacid residues from isophthalic acid.

The polyester may further comprise 0 to 20 mole percent of one or more modified diacids containing 4 to 40 carbon atoms. Examples of modified dicarboxylic acids that can be used include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, or mixtures of two or more of these acids. Specific examples of modified dicarboxylic acids include, but are not limited to, one or more of the following: succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, azelaic acid, dimer acid, or Sulfoisophthalic acid. Other examples of modified dicarboxylic acids are fumaric acid; maleic acid; itaconic acid; 1,3-cyclohexanedicarboxylic acid; diglycolic acid; Dicarboxylic acid; biphenyl acid; 4,4'-oxydibenzoic acid; and 4,4'-sulfonyldibenzoic acid.

The diol residue may comprise 10 to 100 mole percent of 1,4-cyclohexanedimethanol and 0 to 90 mole percent of one or more diols containing 2 to 20 carbon atoms. As used herein, the term "diol" is synonymous with the term "diol" and refers to any dihydric alcohol. Examples of glycols include ethylene glycol; diethylene glycol; triethylene glycol; polyethylene glycol; 1,2-propanediol; 1,3-propanediol; 2,4-dimethyl-2-ethylhexane- 1,3-diol; 2,2-dimethyl-1,3-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1, 3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; neopentyl glycol; 1,6-hexanediol; 1,8-octanediol; 2 , 2,4-trimethyl-1,3-pentanediol; thiodiethanol; 1,2-cyclohexanedimethanol; 1,3-cyclohexanedimethanol; 2,2,4,4- Tetramethyl-1,3-cyclobutanediol; p-xylylene glycol; bisphenol A; bisphenol S; polyglycols; or mixtures of one or more of these diols. Cycloaliphatic diols, such as 1,3- and 1,4-cyclohexanedimethanol, may be present in their pure cis or trans isomers or as a mixture of cis and trans isomers. In another example, the diol residue may comprise 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. In another example, the diol residue may comprise 20 to 70 mole percent 1,4-cyclohexanedimethanol and 80 to 30 mole percent ethylene glycol.

The polyester compositions of the present invention have a glass transition temperature, abbreviated herein as "Tg", of -45°C to 40°C, measured using standard techniques well known to those skilled in the art, such as differential scanning calorimetry ( "DSC"). Tg measurements are typically made using "dry polymers", ie polymer samples where extraneous or absorbed water has been removed by heating the polymer to a temperature of 200°C and allowing the sample to return to room temperature. Typically, polyester compositions are dried in DSC equipment by performing a first thermal scan in which the sample is heated to a temperature above the evaporation temperature of water, maintaining the sample at this temperature until absorption into the polymer After complete water vaporization (indicated by a large, broad endotherm), the sample was cooled to room temperature and a second thermal scan was performed for Tg measurement. Typically, the Tg of the polyester composition is 30°C or less. Other examples of the glass transition temperature of the polyester composition are 25°C or less, 20°C or less, 10°C or less, and 0°C or less.

The inherent viscosity of the polyesters of the present invention, abbreviated herein as "I.V.", is generally from 0.4 to 1.2 dL/g, and preferably from 0.5 to 1.0 dL/g. The term I.V. refers to the inherent viscosity measurement at 25°C using 25 grams of polymer per 50 milliliters of a solvent consisting of 60 weight percent phenol and 40 weight percent tetrachloroethane.

The polyesters of the present invention are readily prepared from appropriate dicarboxylic acids, esters, anhydrides or salts and appropriate diols or diol mixtures using typical polycondensation reaction conditions. They can be manufactured by continuous, semi-continuous and batch modes of operation and various types of reactors can be used. Examples of suitable reactor types include, but are not limited to, stirred tank, continuous stirred tank, slurry, tubular, wiped-film, falling film, or extrusion reactors. As used herein, the term "continuous" refers to a process wherein reactants are introduced and products are withdrawn in a continuous manner. "Continuous" means that the process is substantially or completely continuous in operation, as opposed to a "batch" process. "Continuous" does not in any way prohibit normal interruptions of process continuity, eg, due to start-up, reactor maintenance, or planned shutdown times. The term "batch" process as used herein refers to a process in which all reactants are charged to a reactor and then proceed according to a predetermined course of reaction during which no material is fed to or removed from the reactor. The term "semi-continuous" refers to one in which some reactants are added at the beginning of the process and the remaining reactants are fed continuously as the reaction proceeds. Alternatively, a semi-continuous process can also include a process similar to a batch process in which all reactants are added at the beginning of the process except that one or more products are continuously removed as the reaction proceeds. For economical reasons, and in order to produce polymers of excellent color, it is advantageous to operate the process as a continuous process, since the appearance of the polyester may change if the elevated temperature is allowed to reside in the reactor for too long. bad.

The polyesters of the invention are prepared by procedures known to those skilled in the art. The reaction of the diol component and the dicarboxylic acid component can be carried out using ordinary polyester polymerization conditions. For example, when polyesters are prepared by transesterification, ie starting from the ester form of the dicarboxylic acid component, the reaction process may comprise two steps. In the first step, the dihydric alcohol component and the dicarboxylic acid component, such as dimethyl terephthalate, are reacted at elevated temperature, usually 150°C to 250°C, for 0.5 to 8 hours, and the reaction Pressures range from 0.0 kPa gauge to 414 kPa gauge (60 pounds per square inch, "psig"). Preferably, the temperature of the transesterification reaction is 180° C. to 230° C. for 1 to 4 hours, and the preferred pressure is 103 kPa gauge (15 psig) to 276 kPa gauge (40 psig). Thereafter, the reaction product is heated at elevated temperature and reduced pressure to form the polyester and remove the diol, which under these conditions tends to volatilize and be removed from the system. This second step, or polycondensation step, is continued under higher vacuum and temperature, typically 230°C to 350°C, preferably 250°C to 310°C and most preferably 260°C to 290°C, for 0.1 to 290°C. 6 hours, or preferably 0.2 to 2 hours, until a polymer having the desired degree of polymerization (determined by inherent viscosity) is obtained. The polycondensation step can be performed under reduced pressure, which is 53 kPa (400 Torr) to 0.013 kPa (0.1 Torr). Agitation or appropriate conditions are used in both stages to ensure adequate heat transfer and surface renewal of the reaction mixture. The reaction rate of the two stages is increased by means of suitable catalysts, such as alkoxytitanium compounds, alkali metal hydroxides and alcoholates, organic carboxylates, alkyltin compounds, metal oxides, and the like. A three-stage manufacturing process similar to that described in US Patent 5,290,631 can also be used, especially when using a mixed monomer feed of acid and ester.

In order to ensure that the reaction of the diol component and the dicarboxylic acid component by the transesterification reaction goes to completion, it is sometimes desirable to use 1.05 to 2.5 moles of the diol component per mole of the dicarboxylic acid component. However, those skilled in the art will appreciate that the ratio of the diol component to the dicarboxylic acid component is generally dictated by the reactor design in which the reaction is carried out.

In the preparation of polyesters by direct esterification, i.e. from the acid form of the dicarboxylic acid component, the polyester is obtained by dicarboxylic acid or a mixture of dicarboxylic acids with a diol component or a mixture of diol components React to produce. The reaction is carried out at a pressure of 7 kPa gauge (1 psig) to 1379 kPa gauge (200 psig), preferably less than 689 kPa (100 psig), to produce a low molecular weight, linear or branched polyester product having an average degree of polymerization of 1.4 to 10. The temperature used during the direct esterification reaction is generally 180°C to 280°C, more preferably 220°C to 270°C. The low molecular weight polymer is then polymerized by polycondensation.

The polyester composition also contains a plasticizer. The presence of plasticizers is useful to produce flexible materials with good mechanical properties. Plasticizers also help lower the processing temperature of the polyester and can help prevent the polyester composition from sticking to the calender rolls. Plasticizers generally include one or more aromatic rings. Preferred plasticizers are soluble in polyester as demonstrated by dissolving a 5-mil (.127 mm) thick polyester film to produce a clear solution at a temperature of 160°C or below. In another embodiment, the preferred plasticizer is soluble in polyester, as determined by dissolving a 5-mil (.127 mm) thick polyester film to produce a clear solution at temperatures of 150°C or below. illustrate. The solubility of a plasticizer in polyester can be determined as follows:

1. Place a 1/2 inch section of standard reference film in the vial that is 5 mils (.127 mm) thick and approximately equal in width to the vial.

2. Add plasticizer to the vial until the film is completely covered.

3. The vials containing the film and plasticizer were placed on a rack and observed one hour later and again after four hours. Note the appearance of films and liquids.

4. After environmental observation, place the vial in a heater, allow the temperature to remain constant at 75°C for one hour, and observe the appearance of film and liquid.

5. Repeat step 4 for each of the following temperatures (°C): 100, 140, 150 and 160.

Examples of plasticizers are shown in Table 1 and their solubility determined by the above test. A value of 4 or greater at that temperature indicates that the plasticizer is a candidate for use in the present invention.

Table 1 - Solubility of Plasticizers temperature(℃) twenty three 75 100 140 150 160 Adipic acid derivatives Dioctyl adipate 1 1 1 1 2 2 Bis(2-ethylhexyl)adipate 1 1 1 1 2 2 Di(n-heptyl, n-nonyl) adipate 1 1 1 1 2 2 Diisobutyl adipate 1 3 3 3 3 4 Diisodecyl adipate 1 1 1 1 1 1 Dinonyl adipate 1 1 1 1 1 2 Di(tridecyl)adipate 1 1 1 1 1 1 Azelaic acid derivatives Di(2-ethylhexyl) azelate 1 1 1 1 2 2 Diisodecyl Azelate 1 1 1 1 1 1 Diisooctyl azelate 1 1 1 1 2 2 Dimethyl azelate 3 4 4 4 4 6 Di-n-hexyl azelate 1 1 2 2 3 3 Benzoic acid derivatives Diethylene glycol dibenzoate (DEGDB) 4 4 4 6 6 6 Dipropylene glycol dibenzoate 3 3 4 4 4 6 Propylene glycol dibenzoate 1 3 4 6 6 6 Polyethylene glycol 200 dibenzoate 4 4 4 4 6 6 Neopentyl glycol dibenzoate 0 3 3 3 4 6 Citric acid derivatives Acetyl tri-n-butyl citrate 1 1 1 2 3 3 Acetyl triethyl citrate 1 2 2 2 3 3 Tri-n-butyl citrate 1 2 3 3 3 3 triethyl citrate 3 3 3 3 3 3 dimer acid derivative Bis(2-hydroxyethyl dimerate) 1 1 1 1 2 3 Epoxy derivatives Epoxidized Linseed Oil 1 2 2 2 3 3 Epoxidized soybean oil 1 1 1 1 1 2 temperature(℃) twenty three 75 100 140 150 160 2-Ethylhexyl Epoxy Resinate 1 1 1 1 3 3 Fumaric Acid Derivatives Dibutyl fumarate 2 2 3 3 3 3 Glycerin Derivatives glyceryl tribenzoate 0 0 6 6 6 6 Triacetin 2 3 3 3 3 4 Glyceryl Diacetate Monolaurate 1 2 2 2 2 4 Isobutyrate Derivatives 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate 1 1 1 1 3 3 Texanol diisobutyrate 1 2 2 2 2 4 Isophthalic acid derivatives Dimethyl isophthalate 0 5 5 6 6 6 Diphenyl isophthalate 0 0 0 0 0 0 Di-n-butyl isophthalate 2 3 3 3 3 3 Lauric acid derivatives Methyl laurate 1 2 3 3 3 3 Linoleic acid derivatives Methyl Linoleate, 75% 1 1 2 3 3 3 Maleic acid derivatives Bis(2-ethylhexyl) maleate 1 1 2 3 3 3 Di-n-butyl maleate 2 3 3 3 3 3 Mellitic acid ester Trioctyl trimellitate 1 1 1 1 1 1 Triisodecyl trimellitate 1 1 1 1 1 1 Tri(n-octyl, n-decyl) trimellitate 1 1 1 1 1 1 Triisononyl trimellitate 1 1 1 1 1 1 Myristic Acid Derivatives Isopropyl myristate 1 1 1 2 3 3 Oleic acid derivatives Butyl oleate 1 1 1 2 3 3 glyceryl monooleate 0 1 1 1 3 3 temperature(℃) twenty three 75 100 140 150 160 triolein 1 1 1 1 2 2 methyl oleate 1 1 2 2 3 3 N-Propyl Oleate 1 1 1 2 3 3 Tetrahydrofurfuryl Oleate 1 1 1 2 3 3 Palmitic Acid Derivatives Isopropyl palmitate 1 1 1 1 2 3 Methyl palmitate 0 1 1 2 3 3 Paraffin derivatives Chlorinated paraffin, 41% Cl 1 1 2 2 2 3 Chlorinated Paraffin, 50% Cl 1 2 3 3 3 3 Chlorinated Paraffin, 60% Cl 1 5 6 6 6 6 Chlorinated Paraffin, 70% Cl 0 0 0 0 0 0 Phosphoric acid derivatives 2-Ethylhexyl diphenyl phosphate 2 3 3 3 4 4 Isodecyl diphenyl phosphate 1 2 3 3 3 3 tert-butylphenyl diphenyl phosphate 1 3 3 4 6 6 Resorcinol bis(diphenyl phosphate) (RDP) 100% RDP 1 1 1 3 3 3 Blend of 75% RDP, 25% DEGDB (by weight) 1 2 2 4 4 5 50% RDP, 50% DEGDB (by weight) blend 1 2 5 6 6 6 Blend of 25% RDP, 75% DEGDB (by weight) 1 3 3 6 6 6 tributoxyethyl phosphate 1 2 3 4 4 4 tributyl phosphate 2 3 3 3 3 3 tricresyl phosphate 1 3 3 4 6 6 triphenyl phosphate 0 4 4 6 6 6 Phthalic acid derivatives butyl benzyl phthalate 2 3 3 6 6 6 Texanol Benzyl Phthalate 2 2 2 2 2 4 Butyl octyl phthalate 1 1 2 2 3 3 Dioctyl phthalate 1 1 1 1 2 2 Dicyclohexyl phthalate 0 1 2 2 4 5 temperature(℃) twenty three 75 100 140 150 160 Bis(2-ethylhexyl)phthalate 1 1 1 2 3 3 Diethyl phthalate 4 4 4 6 6 6 Dihexyl phthalate 1 2 3 3 3 3 Diisobutyl phthalate 1 3 3 3 3 5 Diisodecyl phthalate 1 1 1 1 2 2 Diisoheptyl phthalate 1 1 2 3 3 3 Diisononyl phthalate 1 1 1 1 2 3 Diisooctyl phthalate 1 1 2 2 3 3 Dimethyl phthalate 1 5 6 6 6 6 Di(tridecyl)phthalate 1 1 1 1 2 3 Di(undecyl)phthalate 1 1 1 2 2 2 Ricinoleic Acid Derivatives Butyl Ricinoleate 1 1 2 3 3 3 Glyceryl tri(acetyl) ricinoleate 1 1 1 2 1 1 methyl acetyl ricinoleate 1 1 2 3 3 3 methyl ricinoleate 1 2 3 3 3 4 n-Butyl acetyl ricinoleate 1 1 1 2 3 3 Propylene Glycol Ricinoleate 1 1 3 3 4 4 Sebacic acid derivatives Dibutyl sebacate 1 2 3 3 3 3 Bis(2-ethylhexyl) sebacate 1 1 1 2 2 3 Dimethyl sebacate 0 4 4 6 6 6 Stearic acid derivatives Ethylene glycol monostearate 0 1 2 3 3 3 Glyceryl monostearate 0 0 1 2 2 2 Isopropyl isostearate 3 3 3 6 6 6 Methyl stearate 0 1 2 2 2 3 n-Butyl Stearate 1 1 2 3 3 3 Propylene Glycol Monostearate 0 1 1 2 2 3 Succinic acid derivatives Diethyl succinate 3 3 4 5 6 6 temperature(℃) twenty three 75 100 140 150 160 Sulfonic acid derivatives N-Ethyl o, p-toluenesulfonamide 2 5 6 6 6 6 o, p-toluenesulfonamide 0 0 0 6 6 6

illustrate:

0 = plasticizer is solid at this temperature

1 = Plasticizer is liquid, however no change in film

2 = film starts to cloud

3 = Film has swollen

4 = The film begins to change, breaks up and/or the liquid becomes cloudy

5 = no longer a film, liquid is cloudy

6 = Liquid is clear

A test similar to that described above is described in "The Technology of Plasticizers" by J. Kern Sears and Joseph R. Darby, Society of Plastic Engineers/Wiley and Sons, New York Publishing, 1982, 136-137 Page. In this test, a pellet of polymer is placed in a drop of plasticizer on a heated microscope stage. If the polymer disappears, it is dissolved. The most effective plasticizers in dissolving the polyesters of the present invention have a solubility greater than 4 listed in Table 1 and can also be classified according to their solubility parameters. The solubility parameter of a plasticizer, or the square root of the cohesive energy density, can be calculated by the method described by Coleman et al., Polymers, 31, 1187 (1990). Most preferred plasticizers will have a solubility parameter (δ) in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . It is generally understood that the solubility parameter of the plasticizer should be within 1.5 units of that of the polyester. The data in Table 2 show that plasticizers with solubility parameters within this range are capable of dissolving polyester, whereas those plasticizers with solubility parameters outside this range are less effective.

Table 2 plasticizer δ(cal ^0.5 cm ^-1.5 ) Solubility at 160°C obtained from Table 1 Glyceryl Diacetate Monolaurate 8.1 4 Texanol diisobutyrate 8.4 4 Bis(2-ethylhexyl)adipate 8.5 2 trioctyl trimellitate 8.8 1 Bis(2-ethylhexyl)phthalate 8.9 2 Texanol Benzyl Phthalate 9.5 4 Neopentyl glycol dibenzoate 9.8 6 Dipropylene glycol dibenzoate 10.0 6 butyl benzyl phthalate 10.1 6 Propylene Glycol Dibenzoate 10.3 6 Diethylene glycol dibenzoate 10.3 6 glyceryl tribenzoate 10.6 6

Generally, higher molecular weight plasticizers are preferred to prevent smoking and loss of plasticizer during the calendering process. The preferred range of plasticizer content will depend on the properties of the base polyester and plasticizer. In particular, when the Tg of the polyester, as predicted by the well-known Fox formula (T.G. Fox, Bull. Am. Phys. Soc., 1, 123 (1956)), is lowered, the obtained The amount of plasticizer required for the polyester composition is also reduced. Typically, the plasticizer comprises 5 to 50 weight percent (wt%) of the polyester composition, based on the total weight of the polyester composition. Other examples of plasticizer levels are 10 to 40%, 15 to 40%, and 15 to 30% by weight of the polyester composition.

Examples of plasticizers that may be used in accordance with the present invention are esters comprising: (i) residues of acids comprising one or more of the following: phthalic acid, adipic acid, trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citric acid, or phosphoric acid; and (ii) alcohol residues, including one or more alcohols containing up to 20 Aliphatic, cycloaliphatic or aromatic alcohols with carbon atoms. Additional non-limiting examples of alcohol residues of plasticizers include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, hydroquinone, Catechol, Resorcinol, Ethylene Glycol, Neopentyl Glycol, 1,4-Cyclohexanedimethanol and Diethylene Glycol. Plasticizers may also include one or more benzoates, phthalates, phosphates, or isophthalates. In another example, the plasticizer includes diethylene glycol dibenzoate, abbreviated herein as "DEGDB."

The polyester composition also contains a phosphorus-containing flame retardant. Phosphorous flame retardants are miscible with plasticized polyesters. The term "miscible" as used herein is understood to mean that the flame retardant and the plasticized polyester will mix together to form a stable mixture which will not separate into multiple components under processing or use conditions. phase. Thus, the term "miscible" is intended to include "soluble" mixtures (in which the flame retardant and plasticized polyester form a true solution) and "compatible" mixtures (meaning that the flame retardant and plasticized polyester A mixture of does not necessarily form a true solution, but only a stable blend) of both. Preferably, the phosphorus-containing compound is a non-halogenated organic compound, such as a phosphite containing organic substituents. Flame retardants may include a number of phosphorus compounds well known in the art such as phosphines, phosphites, phosphinites, phosphonites, phosphonites, phosphonates, phosphine oxides and phosphates. Examples of phosphorus-containing flame retardants include tributyl phosphate, triethyl phosphate, tributoxyethyl phosphate, tert-butylphenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, phosphoric acid Dimethyl Ethyl Phosphate, Isodecyl Diphenyl Phosphate, Trilauryl Phosphate, Triphenyl Phosphate, Tricresyl Phosphate, Trixylenyl Phosphate, Tert-Butylphenyl Diphenyl Phosphate, Resorcinol bis(diphenyl phosphate), tribenzyl phosphate, ethyl phenyl phosphate, trimethyl thionophosphate, ethyl phenyl thionophosphate, dimethylphosphonic acid Methyl ester, diethyl methyl phosphonate, diethyl pentyl phosphonate, dilauryl methyl phosphonate, diphenyl methyl phosphonate, dibenzyl methyl phosphonate, cresyl phosphine Diphenyl diphenyl ester, dimethyl cresyl phosphonate, dimethyl methylthionophosphonate, phenyl diphenyl phosphinate, benzyl diphenyl phosphinate, diphenyl phosphonite Methyl phosphonate, trimethylphosphine oxide, triphenylphosphine oxide, tribenzylphosphine oxide, 4-methylbiphenylphosphine oxide, triethylphosphite, tributylphosphite, phosphorous acid Trilauryl, triphenyl phosphite, tribenzyl phosphite, diethyl phenyl phosphite, dimethyl phenyl phosphite, dimethyl benzyl phosphite, dimethyl Methyl phosphonite, diethylpentyl phosphonite, diphenylmethyl phosphonite, dibenzyl methyl phosphonite, dimethyl tolyl phosphonite, methyl dimethyl phosphinite, methyl diethyl phosphinite, phenyl di Phenylphosphinite, methyldiphenylphosphinite, benzyldiphenylphosphinite, triphenylphosphine, tribenzylphosphine, and methyldiphenylphosphine.

The term "phosphoric acid" used to describe the phosphorus-containing flame retardants of the present invention includes inorganic acids such as phosphoric acid, acids with direct carbon-phosphorus bonds such as phosphonic and phosphinic acids, and partially esterified phosphorus-containing acids , which contain at least one remaining unesterified acid group, such as phosphate monoesters and diesters, and the like. Typical phosphoric acids that can be used in the present invention include, but are not limited to: dibenzyl phosphoric acid, dibutyl phosphoric acid, di(2-ethylhexyl) phosphoric acid, diphenyl phosphoric acid, methylphenyl phosphoric acid, benzene benzylphosphonic acid, hexylphosphonic acid, phenylphosphonic tolylphosphonic acid, benzylphosphonic acid, 2-phenylethylphosphonic acid, methylhexylphosphinic acid, diphenylphosphinic acid, phenylnaphthylphosphinic acid Phosphonic acid, dibenzylphosphinic acid, methylphenylphosphinic acid, phenylphosphinic acid, tolylphosphinic acid, benzylphosphinic acid, butylphosphonic acid, 2-ethylhexylphosphonic acid, phenylphosphonic acid, Cresyl phosphoric acid, benzyl phosphorous acid, phenyl phosphorous acid, cresyl phosphorous acid, benzyl phosphorous acid, diphenyl phosphorous acid, phenyl benzyl phosphorous acid, dibenzyl phosphorous acid, methylphenyl phosphorous acid, benzene phenylphosphonic acid, tolylmethylphosphonic acid, ethylbenzylphosphonic acid, methylethylphosphonous acid, methylphenylphosphonous acid and phenylphenylphosphonous acid. Flame retardants generally contain one or more mono-, di-, or triesters of phosphoric acid. In another example, the flame retardant comprises resorcinol bis(diphenyl phosphate), abbreviated herein as "RDP."

The flame retardant may be added to the polyester composition at a concentration of 5% to 40% by weight based on the total weight of the polyester composition. Other examples of flame retardant levels are 7% to 35% by weight, 10% to 30% by weight, and 10% to 25% by weight. The flame retardant polyester composition of the present invention usually gives a V2 or higher grade in the UL94 burning test. Additionally, our flame retardant polyester compositions typically give a burn rate of 0 in Federal Motor Vehicle Safety Standard 302 (commonly referred to as FMVSS 302).

Phosphorus-containing flame retardants may also function as plasticizers for polyesters. In this embodiment, the flame retardant may replace some or all of the plasticizer component of the polyester composition, depending on the effectiveness of the flame retardant as a plasticizer. Generally, when using a plasticizing flame retardant, first determine the amount of flame retardant required to obtain the desired burning rate or flame retardancy of the calendered film or sheet, and then determine the desired Tg of the film or sheet. The amount of plasticizer required is adjusted.

A preferred embodiment of the present invention is a flame retardant polyester composition for calendering comprising:

(a) a polyester having a crystallization half-life from the molten state of at least 10 minutes, wherein the polyester is a random copolymer comprising (i) at least 80 mole percent of diacid residues comprising One or more of: terephthalic acid, naphthalene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or isophthalic acid; and (ii) diol residues comprising 20 to 40 mole percent 1,4-cyclohexanedimethanol and 60 to 80 mole percent of one or more glycols containing 2 to 20 carbon atoms, wherein the diacid residue is based on 100 mole percent and the glycol residue The base is based on 100 mole percent;

(b) 10% to 40% by weight of a plasticizer comprising one or more benzoates, phthalates, phosphates or isophthalates;

(c) 5% to 40% by weight of a phosphorus-containing flame retardant that is miscible with the polyester plasticized with a plasticizer; and

(d) An additive effective in preventing polyester from sticking to calender rolls, wherein the weight % is based on the total weight of the polyester composition. Any of the various isomers or mixtures of isomers of naphthalene dicarboxylic acid may be used, but the 1,4-, 1,5-, 2,6- and 2,7-isomers are preferred. At the same time, 1,4-cyclohexanedicarboxylic acid can exist as a pure cis or trans isomer or as a mixture of cis and trans isomers. Glycols, modified diacids and flame retardants are as previously described. Preferred plasticizers include one or more benzoates, phthalates, phosphates or isophthalates, such as listed in Table 1 . Examples of preferred plasticizers include, but are not limited to, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, butyl benzyl phthalate; and texanol phthalate Benzyl esters. Most preferably, the plasticizer includes diethylene glycol dibenzoate and the flame retardant includes resorcinol bis(diphenyl phosphate).

In addition to the polyester, the polyester composition described above contains additives effective to prevent the polyester from sticking to the calender rolls. As used herein, the term "effective" means that the polyester passes freely between calender rolls without wrapping the rolls or creating an excessive layer of polyester on the roll surfaces. The amount of the additive used in the polyester resin composition is usually 0.1 to 10% by weight based on the total weight of the polyester composition. The optimum amount of additive to use is determined by factors well known in the art and depends on equipment, feedstock, process conditions and film thickness. Examples of additives in the present invention include fatty acid amides such as erucylamide and stearamide; metal salts of organic acids such as calcium stearate and zinc stearate; fatty acids, fatty acid salts, and fatty acid esters , such as stearic acid, oleic acid, and palmitic acid; hydrocarbon waxes, such as paraffin waxes, phosphate esters, polyethylene waxes, and polypropylene waxes; chemically modified polyolefin waxes; ester waxes such as carnauba wax; metal salt fin waxes; glycerin Esters such as glyceryl mono- and distearate; talc; microcrystalline silicon dioxide; and acrylic copolymers (eg, PARALOIDX® K175 available from Rohm & Haas). Preferred additives include lauramide, stearamide, calcium stearate, zinc stearate, stearic acid, oleic acid, palmitic acid, paraffin wax, polyethylene wax, polypropylene wax, carnauba wax, monostearin Glyceryl Acid and Glyceryl Distearate. More preferably, the additive is present in the polyester composition in an amount of 0.1 to 2% by weight.

Preferred additives include fatty acids or fatty acid salts containing more than 18 carbon atoms, and (ii) ester waxes containing fatty acid residues containing more than 18 carbon atoms and alcohol residues containing 2 to 28 carbon atoms . The ratio of fatty acid or fatty acid salt to ester wax can be 1:1 or greater. In this embodiment, the mixture of fatty acids or fatty acid salts and ester waxes at the above ratios gives the added benefit of providing a film or sheet with a haze value below 5%. Additives having a fatty acid component containing 18 or less carbon atoms have a lower molecular weight and thus become miscible with the polyester. Such miscible additives have lower interfacial migration surface quality, resulting in poor release or increased haze. In another example, the ratio of fatty acid or fatty acid salt to ester wax is 2:1 or greater.

The fatty acid may include montanic acid, wherein the fatty acid salt may include one or more of the following: sodium montanic acid, calcium montanic acid or lithium montanic acid. The fatty acid residues of the ester wax may include montanic acid. The alcohol residue of the ester wax preferably contains 2 to 28 carbon atoms. Examples of alcohols include montanyl alcohol, ethylene glycol, butylene glycol, glycerin and pentaerythritol. Additives may also include ester waxes which have been partially saponified with a base such as calcium hydroxide.

Oxidative stabilizers may also be used with the polyesters of the invention to prevent oxidative degradation during processing of molten or semi-molten materials on rolls. Such stabilizers include esters such as distearyl thiodipropionate or dilauryl thiodipropionate; phenolic stabilizers such as IRGANOX® 1010 (available from Ciba-Geigy AG), ETHANOX® 330 ( available from Ethyl Corporation), and butylated hydroxytoluene; and phosphorus-containing stabilizers such as IRGAFOS® (available from Ciba-Geigy AG) and WESTON® stabilizers (available from GE Specialty Chemicals). These stabilizers can be used alone Or use a mix.

Melt strength improvers may be used if the melt viscosity and melt strength of the polyester are insufficient to process properly on calendering equipment. Typically, melt strength can be increased by adding small amounts (0.1 to 2.0 mole %) of branching agents to the polyester, either during the initial preparation of the polyester or at a subsequent during the blending or feeding process. Suitable branching agents include polyfunctional acids or diols such as trimellitic acid, trimellitic anhydride, pyromellitic dianhydride, trimethylolpropane, glycerol, pentaerythritol, citric acid, tartaric acid, 3-hydroxyglutaric acid, etc. wait. These branching agents can be added directly to the polyester or blended with the polyester as a concentrate as described in US 5,654,347 and US 5,696,176. Agents such as sulfoisophthalic acid can also be used to increase the melt strength of the polyester to a desired level. In addition, the polyester composition may contain dyes, pigments, fillers, matting agents, antiblocking agents, antistatic agents, blowing agents, chopped fibers, glass, impact modifiers, carbon black, talc, TiO ₂ etc. Colorants (sometimes called toners) may be added to provide the polyester and calendered products with a desired neutral shade and/or brightness.

The components of the polyester composition can be blended in a batch, semi-continuous or continuous process. Small scale batches, prior to calendering, can readily be prepared in any high intensity mixing equipment well known to those skilled in the art, such as a Banbury internal mixer. The components can also be blended in solution in suitable solvents. The melt blending process involves blending the polyester, plasticizer, flame retardant, additives and any other components at a temperature sufficient to melt the polyester. The blend can be cooled and pelletized for further applications, or the melt blend can be calendered directly from this melt blend into film or sheet. The term "melting" as used herein includes, but is not limited to, mere softening of polyester. For melt mixing methods generally known in the art of polymers, reference is made to "Mixing and Compounding of Polymers" (eds. I. Manas-Zloczower & Z. Tadmor, Carl Hanser Verlag Publisher, 1994, New York, N.Y.). When a colored sheet or film is desired, the pigment or colorant can be added to the polyester mixture during the reaction of the diol and dicarboxylic acid, or can be melt blended with preformed polyester. A preferred method of adding colorants is a colorant having a thermally stable organic colored compound with reactive groups such that the colorant is copolymerized and incorporated into the polyester to improve its hue. For example, colorants, such as dyes with reactive hydroxyl and/or carboxyl groups, including but not limited to blue and red substituted anthraquinones, can be copolymerized into the polymer chain. When dyes are used as colorants, they can be added to the polyester process after transesterification or direct esterification.

The present invention also provides a method for producing a flame retardant film or sheet, comprising: calendering a polyester composition comprising (a) a polyester having a melting temperature of at least 5 minutes; State crystalline half-life, wherein the polyester is a random copolymer; (b) a plasticizer; (c) a phosphorus-containing flame retardant, which is miscible with the polyester plasticized with the plasticizer; and (d) Additive that effectively prevents polyester from sticking to calender rolls. The polyesters, plasticizers, flame retardants and additives are as described above for other embodiments of the invention. Polyesters, which are random copolymers, have a crystallization half-life of at least 5 minutes. The crystallization half-life may for example be greater than 7 minutes, greater than 10 minutes, greater than 12 minutes, greater than 20 minutes, greater than 100 minutes and greater than 300 minutes. The film or sheet of the present invention has a Tg of -45°C to 40°C. Typically, films or sheets have a Tg of 30°C or less. Other examples of glass transition temperatures exhibited by the film or sheet are 25°C or less, 20°C or less, 10°C or less, and 0°C or less.

Preferred plasticizers contain one or more aromatic rings, and more preferably, include one or more of benzoate, phthalate, phosphate or isophthalate, for example Table 1 those listed in . Examples of plasticizers include, but are not limited to, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, butyl benzyl phthalate; and texanol benzyl phthalate ester. Typically, the plasticizer comprises 5 to 50 weight percent (wt%) of the polyester composition, based on the total weight of the polyester composition. Other examples of plasticizer levels are 10 to 40%, 15 to 40%, and 15 to 30% by weight of the polyester composition.

The flame retardant may be added to the polyester composition at a concentration of 5% to 40% by weight based on the total weight of the polyester composition. Other examples of flame retardant levels are 7% to 35% by weight, 10% to 30% by weight, and 10% to 25% by weight. Preferably, the flame retardant includes one or more mono-, di- or triesters of phosphoric acid. Phosphorus-containing flame retardants may also function as plasticizers for polyesters. In another example, the plasticizer includes diethylene glycol dibenzoate, and the flame retardant includes resorcinol bis(diphenyl phosphate). Flame-retardant films or sheets usually give a V2 or higher level in the UL94 burning test. Additionally, our flame retardant films or sheets typically give a burn rate of 0 in Federal Motor Vehicle Safety Standard 302 (commonly known as FMVSS 302).

Preferred additives, based on the total weight of the polyester composition, comprise from 0.1% to 10% by weight of one or more fatty acid amides, organic acid metal salts, fatty acids, fatty acid esters, hydrocarbon waxes, phosphate esters, chemically modified Polyolefin waxes, glycerides, talc or acrylic copolymers. In addition, the additive may comprise (i) a fatty acid or a salt of a fatty acid, the fatty acid comprising more than 18 carbon atoms, and (ii) an ester wax comprising a fatty acid residue comprising more than 18 carbon atoms and a fatty acid containing 2 Alcohol residues up to 28 carbon atoms. Preferably, the ratio of fatty acid or fatty acid salt to ester wax is 1:1 or greater. Preferred fatty acids include montanic acid, and preferred fatty acid salts include one or more of: sodium montanic acid, calcium montanic acid, or lithium montanic acid. In addition, preferred fatty acid residues of ester waxes include montanic acid.

The polyester composition is calendered using conventional calendering methods and equipment. In the process of the present invention, the polyester composition may comprise molten pellet or powder form and pass through a compression nip between at least two calender rolls at a temperature of 100°C to 200°C. Typically, polyesters are blended with plasticizers, flame retardants, additives, and other components. The mixed ingredients are masticated in a kneader or extruder. With the aid of heat, shear and pressure, the dry powder is fused to form a homogeneous molten mass. The extruder feeds the molten material into the upper part of the calendering section of the calendering line in a continuous process, between the first and second heated calender rolls. Typically, four rollers are used to form three nips or gaps. For example, the rollers may be configured in an "L" shape, an inverted "L" shape, or a "Z" shape. The size of the rolls can be varied to accommodate different film widths. Rollers have individual temperature and speed controls. The material is carried through the nip between the initial two rollers, which is called the feed nip. The rollers rotate in opposite directions to help spread the material to the width of the rollers. The material is wound between the first and second, second and third, third and fourth rolls, and so on. Between each of the rollers, the gap between the rollers reduces the thickness so that the material thins in the middle of a set of rollers as it advances. Typical processing temperatures for the rolls are generally 80°C to 220°C, preferably 100°C to 200°C and more preferably 130°C to 180°C. For certain hydrolytically unstable polyesters, it is desirable to predry the polyester resin composition or vent excess moisture during processing to prevent degradation of the polymer through hydrolysis. After passing through the calendering section, the material passes through another series of rollers where it is stretched and progressively cooled to form a film or sheet. The material can also be embossed or annealed before cooling. The cooled material is then wound onto master rolls. A general description of the calendering method is published in Jim Butschli, Packaging World, pp. 26-28, June, 1997 and W.V. Titow, PVC Technology, Fourth Edition, pp. 803-848 (1984), Elsevier Publishing Company .

The resulting film or sheet produced from the polyester composition of the present invention has a uniform thickness, which is produced by passing the polyester resin composition through a compression nip between heated rolls. In practice, the polyester resin composition is extruded between the nips between the rollers. Each successive nip between calender rolls decreases in opening size to achieve the final film or sheet thickness.

The present invention also includes a flame retardant film or sheet comprising a polyester composition comprising (a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is random copolymer; (b) a plasticizer; (c) a phosphorus-containing flame retardant that is miscible with polyester plasticized with the plasticizer; and (d) that is effective in preventing the polyester from sticking to calender rolls Additives on , wherein the film or sheet is prepared by calendering the polyester composition. The polyesters, plasticizers, flame retardants and additives are as described above for other embodiments of the invention. Polyesters, which are random copolymers, have a crystallization half-life of at least 5 minutes. The crystallization half-life may for example be greater than 7 minutes, greater than 10 minutes, greater than 12 minutes, greater than 20 minutes, greater than 100 minutes and greater than 300 minutes. The film or sheet preferably has a Tg of 30°C or less. Other examples of the glass transition temperature of the polyester composition are 25°C or less, 20°C or less, 10°C or less, and 0°C or less. Preferred plasticizers contain one or more aromatic rings, and more preferably, include one or more of benzoate, phthalate, phosphate or isophthalate, for example Table 1 those listed in . Examples of plasticizers include, but are not limited to, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, butyl benzyl phthalate; and texanol benzyl phthalate ester. Typically, the plasticizer comprises 5 to 50 weight percent (wt%) of the polyester composition, based on the total weight of the polyester composition. Other examples of plasticizer levels are 10 to 40 wt%, 15 to 40 wt%, and 15 to 30 wt% of the polyester composition.

The flame retardant may be added to the polyester composition at a concentration of 5% to 40% by weight based on the total weight of the polyester composition. Other examples of flame retardant levels are 7% to 35% by weight, 10% to 30% by weight, and 10% to 25% by weight. Preferably, the flame retardant includes one or more mono-, di- or triesters of phosphoric acid. Phosphorus-containing flame retardants may also function as plasticizers for polyesters. Most preferably, the plasticizer includes diethylene glycol dibenzoate and the flame retardant includes resorcinol bis(diphenyl phosphate). Flame-retardant films or sheets usually give a V2 or higher level in the UL94 burning test. Additionally, our flame retardant films or sheets give a burn rate of 0 in Federal Motor Vehicle Safety Standard 302 (commonly known as FMVSS 302).

Preferred additives, based on the total weight of the polysalt composition, comprise from 0.1% to 10% by weight of one or more fatty acid amides, organic acid metal salts, fatty acids, fatty acid salts, fatty acid esters, hydrocarbon waxes, phosphate esters , Chemically modified polyolefin wax, ester wax, glyceride, talc or acrylic copolymer. In addition, the additive may comprise (i) a fatty acid or a salt of a fatty acid, the fatty acid comprising more than 18 carbon atoms, and (ii) an ester wax comprising a fatty acid residue comprising more than 18 carbon atoms and a fatty acid containing 2 Alcohol residues up to 28 carbon atoms. Preferably, the ratio of fatty acid or fatty acid salt to ester wax is 1:1 or greater. The fatty acid preferably includes montanic acid, and the fatty acid salt preferably includes one or more of: sodium montanic acid, calcium montanic acid, or lithium montanic acid. The fatty acid residues of the ester wax preferably include montanic acid.

In addition to the embodiments described above, the present invention also provides a flame retardant polyester composition for calendering, optionally including additives to prevent the polyester composition from sticking to calendering rolls. Accordingly, the present invention provides a flame retardant polyester composition for calendering comprising: (a) 50 to 95 weight percent of a polyester having a melting temperature below 220°C and a temperature at which the polyester has a maximum rate of crystallization having a crystallinity of more than 1% after lower annealing for 2000 minutes, wherein the polyester is a random copolymer; (b) 5 to 50% by weight of a plasticizing compound that is miscible with the polyester, based on the total weight of the polyester composition and (c) a phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer. Polyesters, plasticizers and flame retardants are as described above. The polyester may be a random copolymer having a melting temperature below 220°C and having a crystallinity of more than 1% after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization. The % crystallinity of a polyester can be determined by comparing the heat of fusion of the polyester (as determined by differential scanning calorimetry) to a reference value of 29 cal/g for 100% crystalline polyethylene terephthalate, poly The maximum crystallization rate of an ester can be calculated or determined by means of DSC using methods well known to those skilled in the art. Typically, polyesters have a crystallization half-life of greater than 5 minutes; other examples of crystallization half-lives that polyesters can have are greater than 7 minutes, greater than 10 minutes, greater than 12 minutes, greater than 20 minutes, greater than 100 minutes, and greater than 300 minutes. The polyester composition preferably has a Tg of 30°C or less. Other examples of the glass transition temperature of the polyester composition are 25°C or less, 20°C or less, 10°C or less, and 0°C or less.

The polyester composition may contain 5 to 50%, 10 to 40%, or 15 to 40% by weight of a plasticizer that is miscible with the polyester. Preferred plasticizers contain one or more aromatic rings, and more preferably, include one or more of benzoate, phthalate, phosphate or isophthalate, for example Table 1 those listed in . Examples of plasticizers include, but are not limited to, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, butyl benzyl phthalate; and texanol benzyl phthalate ester.

The flame retardant may be added to the polyester composition at a concentration of 5% to 40% by weight based on the total weight of the polyester composition. Other examples of flame retardant levels are 7% to 35% by weight, 10% to 30% by weight, and 10% to 25% by weight. Preferably, the flame retardant includes one or more mono-, di- or triesters of phosphoric acid. Phosphorus-containing flame retardants may also function as plasticizers for polyesters. Most preferably, the plasticizer includes diethylene glycol dibenzoate and the flame retardant includes resorcinol bis(diphenyl phosphate). The polyester composition may optionally contain additives effective to prevent the polyester from sticking to the calender rolls. This additive has been described previously as part of other embodiments of the invention. The flame retardant polyester composition generally gives a V2 or higher rating in the UL94 burning test. Additionally, our flame retardant polyester compositions give a burn rate of 0 in Federal Motor Vehicle Safety Standard 302 (commonly known as FMVSS 302).

The polyester composition can be formed into a film or sheet by calendering the polymer composition and inducing crystallization before or after the calendering process. Accordingly, another embodiment of the present invention is a method for producing a flame retardant film or sheet comprising: (i) calendering a polyester composition comprising (a) 50 to 95 weight percent polyester, Its melting temperature is lower than 220°C and has a crystallinity of more than 1% after annealing for 2000 minutes at the temperature at which the polyester has a maximum crystallization rate, wherein the polyester is a random copolymer; (b) based on a polyester composition The total weight is 5 to 50% by weight of a plasticizer that is miscible with the polyester; and (c) a phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer and is Crystallization is induced during or after step (i). Furthermore, the present invention includes a film or sheet produced by the above-mentioned method. Accordingly, another aspect of the present invention is a flame retardant film or sheet comprising: (a) 50 to 95 weight percent polyester having a melting temperature below 220°C and at the temperature at which the polyester has a maximum rate of crystallization having greater than 1 percent crystallinity after annealing for 2000 minutes, wherein the polyester is a random copolymer; (b) 5 to 50 weight percent of a plasticizer that is miscible with the polyester; and (c) a phosphorus-containing flame retardant An agent that is miscible with polyester plasticized with a plasticizer. Polyesters, plasticizers and flame retardants are as described above. The calendering process conditions are as described previously; the polyester composition generally comprises molten pellet or powder form and is passed through a compression nip between at least two calender rolls at a temperature of 100°C to 200°C. The polyester may be a random copolymer and have a melting temperature below 220°C and a degree of crystallinity in excess of 1% after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization. Typically, polyesters have a crystallization half-life of greater than 5 minutes; other examples of crystallization half-lives that polyesters can have are greater than 7 minutes, greater than 10 minutes, greater than 12 minutes, greater than 20 minutes, greater than 100 minutes, and greater than 300 minutes. The film or sheet of the present invention has a Tg of -45°C to 40°C, preferably 30°C or below, and a melting temperature higher than 120°C, preferably higher than 140°C. Further examples of polyesters having glass transition temperatures are below 25°C, below 20°C, below 10°C and below 0°C.

The polyester composition comprises 5 to 50% by weight, preferably 10 to 40% by weight or more preferably 15 to 40% by weight of a plasticizer which is miscible with the polyester. Preferred plasticizers contain one or more aromatic rings and may include, for example, one or more of the following: benzoate, phthalate, phosphate or isophthalate, for example in Table Substances listed in 1. Examples of plasticizers include, but are not limited to, neopentyl glycol dibenzoate, diethylene glycol dibenzoate, butyl benzyl phthalate; and texanol benzyl phthalate ester.

The flame retardant may be added to the polyester composition at a concentration of 5% to 40% by weight based on the total weight of the polyester composition. Other examples of flame retardant levels are 7% to 35% by weight, 10% to 30% by weight, and 10% to 25% by weight. The flame retardant may include one or more monoesters, diesters or triesters of phosphoric acid. Phosphorus-containing flame retardants may also function as plasticizers for polyesters. Most preferably, the plasticizer includes diethylene glycol dibenzoate and the flame retardant includes resorcinol bis(diphenyl phosphate). The polyester composition may optionally contain additives effective to prevent the polyester from sticking to the calender rolls. This additive has been described above as part of other embodiments of the invention. Flame-retardant films or sheets usually give a V2 or higher level in the UL94 burning test. Additionally, our flame retardant films or sheets give a burn rate of 0 in Federal Motor Vehicle Safety Standard 302 (commonly known as FMVSS 302).

In step (ii) of the present invention, the polyester composition is calendered to form a film or sheet, and undergoes induced crystallization. Inducing crystallization can be performed during or after the calendering operation. In one embodiment, inducing crystallization is performed by means of stretching after calendering. In another embodiment, crystallization is induced after calendering by annealing at a temperature above the glass transition temperature of the film and below the melting temperature of the base copolyester. In another embodiment, the formation of the film or sheet and the induction of crystallization are carried out together during step (i) by means of calendering only.

The invention is further illustrated by the following examples.

Example

The following is the general procedure for preparing the flame retardant polyester composition and the method of calendering. The flame retardant polyester composition was prepared by combining a mixture with release additive concentrate (Tsunami® ADD2, available from Eastman Chemical Company, which contained 15% by weight of montan wax (available from Clariant Company), and precompounding into Tsunami copolyester GS-2) melt blended pelletized polyester melt blended, the composition of the polyester is to have 80 to 100% by weight of terephthalic acid, 30 to 80% by weight of ethylene glycol and 20 to 70% by weight 1,4-cyclohexanedimethanol (Tsunami(R) copolyester GS-2, available from Eastman Chemical Company). Plasticizers (diethylene glycol dibenzoate or DEGDB, available from Velsicol Chemical Company), phosphate ester flame retardants, and various fillers and colorants (such as _TiO2 colorant concentrate, available from Eastman Chemical Company production) is melt blended with polyester to form a flexible polyester material that can be processed by calendering methods. For this experiment, it was not necessary to dry the polyester pellets, as previous experiments had shown that at the low melting temperatures used for this study, hydrolysis of polyester was not significant. Mixing experiments were performed on a Haake-Buchler Rheocore(R) System 40 using a drum load of 375 grams and a drum temperature of 130°C. In the batch mixer, the blade speed was 100 rpm. For each example, a Lab Viewe(R) computer system was used to record torque and temperature as a function of time. After the torque of the mixing drum reached its peak, mixing was allowed to continue until the melt temperature reached 150°C, then the experiment was stopped and the contents of the mixing drum were removed. Films were calendered on a Dr. Collin instrumented two-roll mill. Because the altered plasticizing effect of the flame retardant affects the polymer system, the set point temperature of the process rolls was varied between 140 and 150°C to have sufficient melt strength and release roll removal from the rolls.

DEGDB was selected as the plasticizer based on its effectiveness in lowering Tg, copolyester compatibility, and transparency of calendered materials. Other plasticizers such as butyl benzyl phthalate, dipropylene glycol dibenzoate, neopentyl glycol dibenzoate, propylene glycol dibenzoate and 2-ethylhexyl-4-hydroxybenzene Formate esters can be used for this application.

Although Examples 1-12 are pigmented opaque formulations, the results apply equally to clear, non-filled systems. Other flame retardants such as melamine, polyphosphate, melamine cyanurate, magnesium hydroxide, aluminum trihydrate and various other commercially available materials such as Flambloc metaboric acid can also be added to the system Salt (available from Buckman Laboratories). The results are shown in Tables 3-7.

Examples 1-12. Table 3 and Table 4 show the composition and combustion test results using resorcinol bis(diphenyl phosphate), "RDP", as a flame retardant. The combustion test is performed in accordance with the UL94 combustion test or the Federal Motor Vehicle Safety Standard 302 (commonly known as FMVSS 302). Examples 1, 2 and 3 are white opaque formulations with calcium carbonate filler and Examples 4, 5 and 6 are white opaque formulations with kaolin filler. Examples 7, 8 and 9 are black opaque formulations with calcium carbonate filler, and Examples 10, 11 and 12 are black opaque formulations with kaolin filler.

As can be seen from the data, the presence of RDP in the copolyester composition reduces the burn rate. The addition of RDP to the copolyester composition increased the burning rating in the UL94 vertical burning test and decreased the burning rate in the FMVSS 302 horizontal burning test. Examples 1, 4, 7 and 10 contained no flame retardant. In these examples, the UL94 vertical burn rating was "Fail" and the horizontal burn rate was in the range of 40 to 50 mm/min. In Examples 2, 5, 8 and 11, half of DEGDB is replaced by RDP. In these examples, the horizontal burn rate was reduced and the UL94 vertical burn test was increased to a V2 rating. In Examples 3, 6, 9 and 12, all DEGDBs are replaced by RDP. In these examples, the UL94 test gave a V2 rating, while the horizontal burn rate was significantly slower than the examples containing less RDP.

table 3

Flame retardant polyester composition (white opaque formulation) Example number 1 2 3 4 5 6 Copolyester (wt%) 57.8 57.8 57.8 57.8 57.8 57.8 Montan wax stripping additive (weight %) 0.9 0.9 0.9 0.9 0.9 0.9 DEGDB (wt%) 15.3 7.65 0 15.3 7.65 0 TiO ₂ (wt%) 6 6 6 6 6 6 Carbon black (wt%) CaCO ₃ (wt%) 20 20 20 Kaolin (weight%) 20 20 20 RDP (wt%) 7.65 15.3 7.65 15.3 Vertical burning test results (UL94) fail V2 V2 fail V2 V2 Average Level Burn Rate (FMVSS 302) 42 36 11 40 2 0 Tg°C of polyester composition twenty two 27 39 19 27 37

Table 4

Flame retardant polyester composition (black opaque formulation) Example number 7 8 9 10 11 12 Copolyester (wt%) 62.5 62.5 62.5 62.5 62.5 62.5 Montan wax stripping additive (weight %) 0.9 0.9 0.9 0.9 0.9 0.9 DEGDB (wt%) 15.6 7.8 0 15.6 7.8 0 TiO ₂ (wt%) Carbon black (wt%) 1 1 1 1 1 1 CaCO ₃ (wt%) 20 20 20 Kaolin (weight%) 20 20 20 RDP (wt%) 7.8 15.6 7.8 15.6 Vertical burning test results (UL94) fail V2 V2 fail V2 V2 Average Level Burn Rate (FMVSS 302) 50 47 25 52 17 no data obtained Tg℃ twenty four 31 40 twenty two 29 38

RDP can also be used to replace all or part of the plasticizer. When DEGDB was replaced by RDP, the Tg of the material increased. The Tg of the non-plasticized formulation was 80°C. RDP can be used with both rigid and flexible formulations. RDP lowers the Tg of the polyester composition, but less effectively than DEGDB. In order to maintain the proper Tg of the flexible formulation, it is often necessary to add additional DEGDB or other plasticizers back into the polyester composition. Table 5 shows the effect of mixtures of DEGDB and RDP on the Tg of the polyester compositions. The data in Table 5 include the substitution of RDP for DEGDB (1:1) and the addition of RDP to the formulations without a decrease in DEGDB levels.

table 5

Effect of DEGDB and RDP on Tg Tg of composition, ℃ twenty two 16 11 10 -3 twenty three 26 twenty one 29 twenty three 14 36 80 38 DEGBD (wt%) 2017.51.51050

0 5 10 15 20

RDP (wt%)

The actual level required to maintain a Tg below or equal to room temperature is approximately equivalent to substituting 2xRDP for DEGDB. The predicted data in Table 6 shows the expected level of DEGBD required to maintain Tg at room temperature at various RDP levels.

Table 6

Estimated levels of RDP and DEGDB RDP (wt%) DEGDB (wt%) Tg(°C) 0 20 twenty two 5 17.5 twenty three 10 15 twenty one 15 10 twenty three 20 6 20

Examples 13-20. Flame retardant polyester compositions were prepared using the general procedure described above, but using various phosphate ester flame retardants at a concentration of 10% by weight based on the total weight of the polyester composition. The results are shown in Table 7.

Table 7 Example flame retardant average burning rate Tg℃ 13 NCENDX® P-30b (available from Albemarle Chemical Company) 0 15 14 trilauryl phosphite 0 15 Triphenyl Phosphate 0 -4 16 Reofos 507 (triaryl phosphate "TAP"; tert-butylated TAP; mixture of mono(tert-butylphenyl)diphenyl phosphates, available from Great Lakes Chemical Company) 0 (2 samples) 48 (1 sample) 6 17 bisphenol-A diphosphate 0 12 18 Tris-xylenyl phosphate 0 4 19 tricresyl phosphate 0 -12 20 Isodecyl Phosphate Diphenyl Ester 87 -8

claims

(Amended in accordance with Article 19 of the Treaty)

1. A flame-retardant polyester composition for calendering, comprising:

(a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is a random copolymer;

(b) plasticizers;

(c) a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and

(d) Additives effective in preventing polyester from sticking to calender rolls.

2. The polyester composition of claim 1, wherein said plasticizer comprises one or more aromatic rings, based on the total weight of said polyester composition, being 10 to 40 weight percent of said polyester composition, And dissolving a 5-mil (.127 mm) thick film of the polyester yielded a clear solution at a temperature of 160°C or below.

3. The polyester composition of claim 2, wherein the plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 .

4. The polyester composition of claim 3, wherein said plasticizer is an ester comprising

(i) acid residues comprising one or more of the following: phthalic acid, adipic acid, trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric, glutaric, citric, or phosphoric acid; and

(ii) Alcohol residues, which include one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, terephthalate Phenol, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol.

5. The polyester composition of claim 4, wherein said polyester has a crystallization half-life of at least 12 minutes.

6. The polyester composition of claim 5, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 One or more dihydric alcohols selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl Diol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4-tetra Methyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol.

7. The polyester composition of claim 6, wherein the diol residue comprises 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol.

8. The polyester composition of claim 6, wherein said diacid residues further comprise 0 to 20 mole percent of one or more modified diacids comprising one or more of the following: succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, azelaic acid, dimer acid, or sulfoisophthalic acid; and said plasticizers include benzoates, phthalates One or more of acid esters, phosphate esters or isophthalates.

9. The polyester composition of claim 8, wherein the plasticizer comprises diethylene glycol dibenzoate.

10. The polyester composition of claim 8, wherein the flame retardant comprises 5 to 40% by weight of one or more phosphoric acid monoesters, diesters or triesters based on the total weight of the polyester composition .

11. The polyester composition of claim 10, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate).

12. The polyester composition of claim 10, wherein the polyester composition has a Tg of 30°C or less.

13. The polyester composition of claim 1, wherein said crystallization half-life from the molten state is at least 10 minutes; said polyester comprises (i) at least 80 mole percent diacid residues comprising One or more of: terephthalic acid, naphthalene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or isophthalic acid; and (ii) diol residues comprising 20 to 40 mole percent 1,4-cyclohexanedimethanol and 60 to 80 mole percent of one or more dihydric alcohols containing 2 to 20 carbon atoms, wherein the diacid residues are based on 100 mole percent and the dibasic Alcohol residues are based on 100 mole percent; and wherein the polyester composition comprises 10% to 40% by weight of a plasticizer comprising benzoate, phthalate, phosphate, or isophthalic one or more formate esters; 5% by weight to 40% by weight of a phosphorus-containing flame retardant capable of being miscible with the polyester plasticized with the plasticizer; and effectively preventing the polyester from sticking to Additives on calender rolls, wherein the weight % is based on the total weight of the polyester composition.

14. The polyester composition of claim 13, wherein the additive comprises 0.1% to 10% by weight of one or more of the following substances based on the total weight of the polyester composition: fatty acid amides, metal salts of organic acids, Fatty acids, fatty acid salts, fatty acid esters, hydrocarbon waxes, ester waxes, phosphate esters, chemically modified polyolefin waxes; glycerides, talc or acrylic copolymers.

15. The polyester composition of claim 14, wherein said additives include lauramide, stearamide, calcium stearate, zinc stearate, stearic acid, oleic acid, palmitic acid, paraffin wax, polyethylene wax , Polypropylene Wax, Carnauba Wax, Glyceryl Monostearate and Glyceryl Distearate.

16. The polyester composition of claim 14, wherein the additive comprises (i) a fatty acid or a salt of a fatty acid containing more than 18 carbon atoms, and (ii) an ester wax comprising a fatty acid containing more than 18 carbon atoms Fatty acid residues and alcohol residues containing 2 to 28 carbon atoms, wherein the ratio of the fatty acid or fatty acid salt to the ester wax is 1:1 or greater.

17. The polyester composition of claim 16, wherein said fatty acid comprises montanic acid; said fatty acid salt comprises one or more of the following: montanic acid sodium salt, montanic acid calcium salt or montanic acid lithium salt; The fatty acid residue of the ester wax includes montanic acid; and the alcohol residue of the ester wax includes one or more of: montanyl alcohol, ethylene glycol, butanediol, glycerin, or pentaerythritol.

18. The polyester composition of claim 17, wherein the ester wax has been partially saponified with calcium hydroxide.

19. The polyester composition of claim 18, wherein the ratio of said fatty acid or fatty acid salt to said ester wax is 2:1 or greater.

20. A method of producing a flame retardant film or sheet comprising calendering the polyester composition according to any one of claims 1-19.

21. A flame retardant film or sheet comprising the polyester composition according to any one of claims 1-19.

22. A flame retardant polyester composition for calendering comprising:

(a) 50 to 95 percent by weight of a polyester having a melting temperature below 220° C. and having a crystallinity of more than 1 percent after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization, wherein the polyester is free Regular copolymer;

(b) 5 to 50% by weight, based on the total weight of the polyester composition, of a plasticizer that is miscible with the polyester; and

(c) A phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer.

23. The polyester composition of claim 22, further comprising an additive (d) effective to prevent the polyester from sticking to calender rolls.

24. The polyester composition of claim 23, wherein the plasticizer comprises one or more aromatic rings; based on the total weight of the polyester composition, it is 10 to 40% by weight of the polyester composition, and dissolving a 5-mil (.127 mm) thick film of the polyester yielded a clear solution at a temperature of 160°C or below.

25. The polyester composition of claim 24, wherein the plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 .

26. The polyester composition of claim 25, wherein said plasticizer is an ester comprising

(i) acid residues comprising one or more of the following: phthalic acid, adipic acid, trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric, glutaric, citric, or phosphoric acid; and

(ii) Alcohol residues, which include one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, terephthalate Phenol, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol.

27. The polyester composition of claim 26, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 One or more dihydric alcohols selected from the following mole percentages: ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, Neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4 - tetramethyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein said diacid residue is based on 100 mole percent, and The diol residues are based on 100 mole percent.

28. The polyester composition of claim 27, wherein the plasticizer comprises diethylene glycol dibenzoate.

29. The polyester composition of claim 28, wherein based on the total weight of the polyester composition, the flame retardant comprises 5 to 40% by weight of one or more phosphoric acid monoesters, diesters or triesters .

30. The polyester composition of claim 29, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate).

31. The polyester composition of claim 30, wherein the polyester composition has a Tg of 30°C or less.

32. A method for producing a flame retardant film or sheet comprising (i) calendering the polyester composition of any one of claims 22-31; and (ii) during step (i) or during step (i ) followed by induction of crystallization.

33. A flame retardant film or sheet comprising the polyester composition according to any one of claims 22-31.

Claims (113)

1. A flame-retardant polyester composition for calendering, comprising: (a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is a random copolymer; (b) plasticizers; (c) a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and (d) Additives effective in preventing polyester from sticking to calender rolls. 2. The polyester composition of claim 1, wherein the plasticizer comprises one or more aromatic rings. 3. The polyester composition of claim 2, wherein the plasticizer comprises 10 to 40 weight percent of the polyester composition based on the total weight of the polyester composition. 4. The polyester composition of claim 3, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 5. The polyester composition of claim 4, wherein the plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 6. The polyester composition of claim 5, wherein said plasticizer is an ester comprising (i) acid residues, said acid comprising one or more of: phthalic acid, adipic acid , trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citric acid, or phosphoric acid; and (ii) Alcohol residues, including one or more aliphatic, cycloaliphatic or aromatic alcohols containing up to 20 carbon atoms. 7. The polyester composition of claim 6, wherein the alcohol residue of the plasticizer is methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzene Methanol, hydroquinone, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 8. The polyester composition of claim 7, wherein the polyester has a crystallization half-life of at least 12 minutes. 9. The polyester composition of claim 8, wherein the crystallization half-life is at least 300 minutes. 10. The polyester composition of claim 9, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 The mole percent of one or more diols comprising 2 to 20 carbon atoms, wherein the diacid residues are based on 100 mole percent, and the diol residues are based on 100 mole percent. 11. The polyester composition of claim 10, wherein said glycol residues comprise one or more glycols selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol , 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl 1,3-pentanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene diol. 12. The polyester composition of claim 11, wherein the diol residues comprise 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 13. The polyester composition of claim 12, wherein the diacid residues further comprise 0 to 20 mole percent of one or more modified diacids comprising 4 to 40 carbon atoms. 14. The polyester composition of claim 13, wherein said modified diacid comprises one or more of the following: succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, azelaic acid, dimer acid or sulfoisophthalic acid. 15. The polyester composition of claim 14, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 16. The polyester composition of claim 15, wherein the plasticizer comprises diethylene glycol dibenzoate. 17. The polyester composition of claim 16, wherein the flame retardant comprises 5 to 40% by weight of one or more monoesters, diesters or triesters of phosphoric acid, based on the total weight of the polyester composition . 18. The polyester composition of claim 17, wherein said flame retardant is a plasticizer for said polyester. 19. The polyester composition of claim 18, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate). 20. The polyester composition of claim 19, wherein the polyester composition has a Tg of 30°C or less. 21. The polyester composition of claim 20, wherein the polyester composition has a Tg of 20°C or less. 22. A flame retardant polyester composition for calendering comprising: (a) a polyester having a crystallization half-life from the molten state of at least 10 minutes, wherein the polyester is a random copolymer comprising (i) at least 80 mole percent of diacid residues, the diacid residues comprising one or more of: terephthalic acid, naphthalene dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or isophthalic acid; and (ii) diol residues comprising 20 to 40 Mole percent 1,4-cyclohexanedimethanol and 60 to 80 mole percent of one or more dihydric alcohols containing 2 to 20 carbon atoms, wherein the diacid residue is based on 100 mole percent and the Glycol residues are based on 100 mole percent; (b) 10% to 40% by weight of a plasticizer comprising one or more benzoates, phthalates, phosphates or isophthalates; (c) 5% to 40% by weight of a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and (d) An additive effective in preventing polyester from sticking to calender rolls, wherein the weight % is based on the total weight of the polyester composition. 23. The polyester composition of claim 22, wherein the additive comprises 0.1% to 10% by weight of one or more of the following substances based on the total weight of the polyester composition: fatty acid amides, metal salts of organic acids, Fatty acids, fatty acid salts, fatty acid esters, hydrocarbon waxes, ester waxes, phosphate esters, chemically modified polyolefin waxes; glycerides, talc or acrylic copolymers. 24. The polyester composition of claim 23, wherein said additives include cincylamide, stearamide, calcium stearate, zinc stearate, stearic acid, oleic acid, palmitic acid, paraffin, polyethylene wax, polypropylene Wax, carnauba wax, glyceryl monostearate and glyceryl distearate. 25. The polyester composition of claim 24, further comprising (e) an oxidation stabilizer. 26. The polyester resin composition of claim 25, further comprising (f) a melt strength improver. 27. The polyester composition of claim 23, wherein the additive comprises (i) a fatty acid or a salt of a fatty acid containing more than 18 carbon atoms, and (ii) an ester wax comprising a fatty acid containing more than 18 carbon atoms Fatty acid residues and alcohol residues containing 2 to 28 carbon atoms, wherein the ratio of the fatty acid or fatty acid salt to the ester wax is 1:1 or greater. 28. The polyester composition of claim 27, wherein the additive is present at 0.1 to 2 weight percent. 29. The polyester composition of claim 28, wherein said fatty acid comprises montanic acid; said fatty acid salt comprises one or more of the following: sodium montanic acid, calcium montanic acid, or lithium montanic acid; and The fatty acid residues of the ester wax include montanic acid. 30. The polyester composition of claim 29, wherein the alcohol residue of the ester wax comprises one or more of the following: montanyl alcohol, ethylene glycol, butylene glycol, glycerin, or pentaerythritol. 31. The polyester composition of claim 30, wherein the ester wax has been partially saponified with calcium hydroxide. 32. The polyester composition of claim 31, wherein the ratio of said fatty acid or fatty acid salt to said ester wax is 2:1 or greater. 33. A method for producing a flame retardant film or sheet comprising calendering a polyester composition comprising (a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is a random copolymer; (b) plasticizers; (c) a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and (d) Additives effective in preventing polyester from sticking to calender rolls. 34. The method of claim 33, wherein the plasticizer comprises one or more aromatic rings. 35. The method of claim 34, wherein the plasticizer comprises 10 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 36. The method of claim 35, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 37. The method of claim 36, wherein the plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 38. The method of claim 37, wherein said plasticizer is an ester comprising (i) acid residues, said acid comprising one or more of: phthalic acid, adipic acid, trimene triacids, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citric acid, or phosphoric acid; and (ii) alcohol residues comprising one or more of the following: Methanol, Ethanol, Propanol, Isopropanol, Butanol, Isobutanol, Stearyl Alcohol, Lauryl Alcohol, Phenol, Benzyl Alcohol, Hydroquinone, Catechol, Resorcinol, Ethylene Glycol, Neo Pentylene glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 39. The method of claim 38, wherein the polyester composition comprises molten pellet or powder form and is passed through a compression nip between at least two calender rolls at a temperature of 100°C to 200°C. 40. The method of claim 39, wherein said polyester has a crystallization half-life of at least 300 minutes. 41. The method of claim 40, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene dicarboxylic acid , 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) diol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent One or more glycols selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyldiol Alcohol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4-tetramethyl base-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein the diacid residue is based on 100 mole percent, and the two Alcohol residues are based on 100 mole percent. 42. The method of claim 41, wherein the diol residue comprises 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 43. The polyester composition of claim 42, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 44. The polyester composition of claim 43, wherein the plasticizer comprises diethylene glycol dibenzoate. 45. The method of claim 44, wherein the flame retardant comprises 5 to 40 weight percent of one or more monoesters, diesters, or triesters of phosphoric acid, based on the total weight of the polyester composition. 46. The method of claim 45, wherein said flame retardant is a plasticizer for said polyester. 47. The method of claim 46, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate). 48. The method of claim 47, wherein the polyester composition has a Tg of 30°C or less. 49. The method of claim 48, wherein the additive comprises 0.1% to 10% by weight, based on the total weight of the polyester composition, of one or more of the following: fatty acid amides, metal salts of organic acids, fatty acids, fatty acids salts, fatty acid esters, hydrocarbon waxes, ester waxes, phosphate esters, chemically modified polyolefin waxes; glycerides, talc or acrylic copolymers. 50. The method of claim 49, wherein the additives include (i) fatty acids containing more than 18 carbon atoms or salts of fatty acids, and (ii) ester waxes containing fatty acid residues containing more than 18 carbon atoms and alcohol residues containing 2 to 28 carbon atoms, wherein the ratio of the fatty acid or fatty acid salt to the ester wax is 1:1 or greater. 51. The method of claim 50, wherein said fatty acid comprises montanic acid; said fatty acid salt comprises one or more of the following: sodium montanic acid, calcium montanic acid, or lithium montanic acid; and said ester The fatty acid residues of the wax include montanic acid. 52. A flame retardant film or sheet comprising a polyester composition comprising (a) a polyester having a crystallization half-life from the molten state of at least 5 minutes, wherein the polyester is a random copolymer; (b) plasticizers; (c) a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and (d) An additive capable of effectively preventing polyester from sticking to calendering rolls, wherein the film or sheet is produced by calendering the polyester composition. 53. The film or sheet of claim 52, wherein the plasticizer comprises one or more aromatic rings. 54. The film or sheet of claim 53, wherein the plasticizer comprises 10 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 55. The film or sheet of claim 54, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 56. The film or sheet of claim 55, wherein said plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 57. The film or sheet of claim 56, wherein said plasticizer is an ester comprising (i) acid residues, said acid comprising one or more of: phthalic acid, adipic acid , trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citric acid, or phosphoric acid; and (ii) alcohol residues comprising one or Various: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, hydroquinone, catechol, resorcinol, ethylene glycol alcohol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 58. The film or sheet of claim 57, wherein the polyester has a crystallization half-life of at least 300 minutes. 59. The film or sheet of claim 58, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 One or more dihydric alcohols selected from the following mole percentages: ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, Neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4 - tetramethyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein said diacid residue is based on 100 mole percent, and The diol residues are based on 100 mole percent. 60. The film or sheet of claim 59, wherein the diol residues comprise 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 61. The polyester composition of claim 60, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 62. The polyester composition of claim 61, wherein the plasticizer comprises diethylene glycol dibenzoate. 63. The film or sheet of claim 62, wherein the flame retardant comprises 5 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 64. The film or sheet of claim 63, wherein said flame retardant is a plasticizer for said polyester. 65. The film or sheet of claim 64, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate). 66. The film or sheet of claim 65, wherein the polyester composition has a Tg of 30°C or less. 67. The film or sheet of claim 66, wherein the additive comprises 0.1% to 10% by weight, based on the total weight of the polyester composition, of one or more of the following: fatty acid amides, metal salts of organic acids, Fatty acids, fatty acid salts, fatty acid esters, hydrocarbon waxes, ester waxes, phosphate esters, chemically modified polyolefin waxes; glycerides, talc or acrylic copolymers. 68. The film or sheet of claim 67, wherein the additives include (i) fatty acids containing more than 18 carbon atoms or salts of fatty acids, and (ii) ester waxes containing fatty acids containing more than 18 carbon atoms Fatty acid residues and alcohol residues containing 2 to 28 carbon atoms, wherein the ratio of the fatty acid or fatty acid salt to the ester wax is 1:1 or greater. 69. The film or sheet of claim 68, wherein the fatty acid comprises montanic acid; the fatty acid salt comprises one or more of the following: sodium montanate, calcium montanate, or lithium montanate; and The fatty acid residues of the ester wax include montanic acid. 70. A flame retardant polyester composition for calendering comprising: (a) 50 to 95 percent by weight of a polyester having a melting temperature below 220° C. and having a crystallinity of more than 1 percent after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization, wherein the polyester is free Regular copolymer; (b) 5 to 50% by weight, based on the total weight of the polyester composition, of a plasticizer that is miscible with the polyester; and (c) A phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer. 71. The polyester composition of claim 70, wherein the plasticizer comprises one or more aromatic rings. 72. The polyester composition of claim 71, further comprising an additive (d) effective to prevent the polyester from sticking to calender rolls. 73. The polyester composition of claim 72, wherein the plasticizer comprises 10 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 74. The polyester composition of claim 73, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 75. The polyester composition of claim 74, wherein said plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 76. The polyester composition of claim 75, wherein said plasticizer is an ester comprising (i) Acid residues comprising one or more of the following: phthalic acid, adipic acid, trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid , glutaric, citric, or phosphoric acid; and (ii) Alcohol residues, which include one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, terephthalate Phenol, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 77. The polyester composition of claim 76, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 One or more dihydric alcohols selected from the following mole percentages: ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, Neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4 - tetramethyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein said diacid residue is based on 100 mole percent, and The diol residues are based on 100 mole percent. 78. The polyester composition of claim 77, wherein said diol residues comprise 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 79. The polyester composition of claim 78, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 80. The polyester composition of claim 79, wherein the plasticizer comprises diethylene glycol dibenzoate. 81. The polyester composition of claim 80, wherein based on the total weight of the polyester composition, the flame retardant comprises 5 to 40% by weight of one or more phosphoric acid monoesters, diesters or triesters . 82. The polyester composition of claim 81, wherein said flame retardant is a plasticizer for said polyester. 83. The polyester composition of claim 82, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate). 84. The polyester composition of claim 83, wherein the polyester composition has a Tg of 30°C or less. 85. A method for producing a flame retardant film or sheet comprising: (i) calendering a polyester composition comprising (a) 50 to 95 percent by weight of a polyester having a melting temperature below 220° C. and having a crystallinity of more than 1 percent after annealing for 2000 minutes at a temperature at which the polyester has a maximum rate of crystallization, wherein the polyester is free Regular copolymer; (b) 5 to 50% by weight, based on the total weight of the polyester composition, of a plasticizer that is miscible with the polyester; and (c) a phosphorus-containing flame retardant that is miscible with said polyester plasticized with said plasticizer; and Crystallization is induced during step (i) or after step (i). 86. The method of claim 85, wherein the plasticizer comprises one or more aromatic rings. 87. The method of claim 86, wherein the plasticizer comprises 10 to 40 weight percent of the polyester composition, based on the total weight of the polyester composition. 88. The method of claim 87, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 89. The method of claim 88, wherein said plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 90. The method of claim 89, wherein said plasticizer is an ester comprising (i) acid residues, said acid comprising one or more of: phthalic acid, adipic acid, trimene Triacids, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric acid, glutaric acid, citric acid, or phosphoric acid; and (ii) Alcohol residues, which include one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, terephthalate Phenol, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 91. The method of claim 90, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene dicarboxylic acid , 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) diol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent One or more glycols selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyldiol Alcohol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4-tetramethyl base-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein the diacid residue is based on 100 mole percent, and the two Alcohol residues are based on 100 mole percent. 92. The method of claim 91, wherein the diol residue comprises 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 93. The polyester composition of claim 92, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 94. The polyester composition of claim 93, wherein the plasticizer comprises diethylene glycol dibenzoate. 95. The method of claim 94, wherein the flame retardant comprises 5 to 40 weight percent of one or more monoesters, diesters, or triesters of phosphoric acid, based on the total weight of the polyester composition. 96. The method of claim 95, wherein said flame retardant is a plasticizer for said polyester. 97. The method of claim 96, wherein the flame retardant comprises resorcinol bis(diphenyl phosphate). 98. The method of claim 97, wherein the polyester composition has a Tg of 30°C or less. 99. The method of claim 98, wherein the polyester composition comprises molten pellet or powder form and is passed through a compression nip between at least two calender rolls at a temperature of 100°C to 200°C. 100. A flame retardant film or sheet comprising: (a) 50 to 95 percent by weight of a polyester having a melting temperature below 220° C. and having a crystallinity of more than 1 percent after annealing for 2000 minutes at the temperature at which the polyester has a maximum rate of crystallization, wherein the polyester is free Regular copolymer; (b) 5 to 50 weight percent of a plasticizer that is miscible with the polyester; and (c) A phosphorus-containing flame retardant that is miscible with the polyester plasticized with the plasticizer. 101. The film or sheet of claim 100, wherein the plasticizer comprises one or more aromatic rings. 102. The film or sheet of claim 101, wherein the plasticizer comprises 10 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 103. The film or sheet of claim 102, wherein said plasticizer dissolves a 5-mil (.127 mm) thick film of said polyester to produce a clear solution at a temperature of 160°C or below. 104. The film of claim 103 or wherein said plasticizer has a solubility parameter in the range of 9.5 to 13.0 cal ^0.5 cm ^-1.5 . 105. The film or sheet of claim 104, wherein said plasticizer is an ester comprising (i) acid residues comprising one or more of the following: phthalic acid, adipic acid, trimellitic acid, benzoic acid, azelaic acid, terephthalic acid, isophthalic acid, butyric, glutaric, citric, or phosphoric acid; and (ii) Alcohol residues, which include one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, stearyl alcohol, lauryl alcohol, phenol, benzyl alcohol, terephthalate Phenol, catechol, resorcinol, ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol or diethylene glycol. 106. The film or sheet of claim 105, wherein said polyester comprises (i) at least 80 mole percent diacid residues comprising one or more of the following: terephthalic acid, naphthalene Dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or isophthalic acid; and (ii) dihydric alcohol residues comprising 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 One or more dihydric alcohols selected from the following mole percentages: ethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, Neopentyl glycol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4,4 - tetramethyl-1,3-cyclobutanediol, 1,3-cyclohexanedimethanol, bisphenol A and polyalkylene glycol, wherein said diacid residue is based on 100 mole percent, and The diol residues are based on 100 mole percent. 107. The film or sheet of claim 106, wherein said glycol residues comprise 10 to 100 mole percent 1,4-cyclohexanedimethanol and 0 to 90 mole percent ethylene glycol. 108. The polyester composition of claim 107, wherein the plasticizer comprises one or more of the following: benzoate, phthalate, phosphate, or isophthalate. 109. The polyester composition of claim 108, wherein the plasticizer comprises diethylene glycol dibenzoate. 110. The film or sheet of claim 109, wherein the flame retardant comprises 5 to 40% by weight of the polyester composition, based on the total weight of the polyester composition. 111. The film or sheet of claim 110, wherein said flame retardant is a plasticizer for said polyester. 112. The film or sheet of Claim 111, wherein said flame retardant comprises resorcinol bis(diphenyl phosphate). 113. The film or sheet of claim 112, wherein the polyester composition has a Tg of 30°C or less.