JPH0576975B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a polyester having ethylene terephthalate as a main constituent unit, which has excellent mechanical properties such as bending strength and bending rigidity, and heat resistance, and has an improved crystallization rate. [Prior Art] Conventionally, substantially linear polyesters containing ethylene terephthalate as the main constituent unit, such as polyethylene terephthalate, have excellent properties such as rigidity, heat resistance, and gas barrier properties, and have been used in films, sheets, laminates, and containers. Although it is used as a material for molded objects of various shapes such as, it has the disadvantage that it has a slow crystallization rate and cannot be molded at high speed. Therefore, in order to improve the crystallization rate of the polyester, measures such as increasing the temperature of the molding die have been adopted, but these methods have drawbacks such as thermal deterioration of the resin and warping of the molded product. Therefore, methods have been proposed in which various additives are added to the polyester for the purpose of increasing the crystallization rate of the polyester and improving mechanical properties such as flexural rigidity and heat resistance. These methods include methods of blending talc and other various inorganic compounds with the polyester, methods of blending metal salts of aliphatic or aromatic carboxylic acids, methods of blending polyalkylene glycols, alkoxypolyalkylene glycols, ethylene/(meth) ) Methods of blending various polymers such as acrylate copolymers, unsaturated polyesters, and polyamides are also known. Among them, a copolymer of ethylene or styrene and salts such as acrylic acid and methacrylic acid was proposed in the Japanese Patent Publication Publication No. 1972-26225.
-47058, 55-47059 and JP-A-59-15445 propose a technique of blending a filler material, etc., with a sodium or potassium salt of an organic polymer having pendant carboxyl groups and an organic ester. . Also, JP-A No. 56-145943, No. 56-
No. 127655 and No. 57-145145 propose a technique of blending a copolymer salt similar to the above and polyalkylene glycol or a derivative thereof. Furthermore, JP-A-58-76446 and JP-A-57-8241 propose techniques for blending specified polyethers and esters. However, although the crystallization rate of the polyester can be considerably improved by adding these additives, the crystallization rate has not been improved enough to satisfy the current demands for high-speed moldability. The reason why a sufficient crystallization rate cannot be obtained even when the above additives are blended is considered to be that the mobility of polyester molecules at low temperatures is insufficient. In other words, when polyester is molded under rapid cooling conditions, the polyester molecules become glassy in a short time and their molecular motion is frozen, making it impossible to crystallize, resulting in insufficient heat resistance and mechanical properties. It is presumed that this cannot be realized. Based on this idea, the present inventors used a thiodiethanol compound as a plasticizer and a crystallization promoter [component (C) of the present invention] in combination to increase the mobility of polyester molecules at low temperatures. We are proposing technology. [Problems to be solved by the invention] However, in conventional polyester compositions of this type, many of the low molecular weight organic compounds added as plasticizers are volatile at the molding temperature, so they do not evaporate during molding. There were problems such as re-adhesion to the molded surface. [Means for Solving the Problems] Therefore, the polyester composition of the present invention contains the following (b ₁ ) per 100 parts by weight of the substantially linear polyester (A) having ethylene terephthalate as the main constituent unit. to (b ₂ ) in a range of 0.1 to 15 parts by weight of the sulfur-containing polyester condensate (B) and a crystallization promoter (C) in a range of 0.05 to 15 parts by weight. (b ₁ ) General formula () (HY-R) ₂ S () (However, two R are homologs selected from the group of aliphatic, alicyclic, aromatic and combinations thereof having two or more carbon atoms. A sulfur-containing polyester condensate derived from a compound having one or different hydrocarbon groups (two Y's being the same or different and representing oxygen or sulfur) and an organic dicarboxylic acid. (b ₂ ) A sulfur-containing polyester condensate derived from an organic dicarboxylic acid and a compound selected from the group of condensates of the compound represented by the general formula () and an organic monomer having two hydroxyl groups. The present invention will be explained in detail below. [About component (A)] The polyester (A) blended into the polyester composition of the present invention is a substantially linear polyester containing ethylene terephthalate as a main constituent unit. The content of ethylene terephthalate structural units in the polyester is 70 mol% or more, preferably 80 mol% or more. The dicarboxylic acid component units constituting the polyester may contain a small amount of other aromatic dicarboxylic acid component units in addition to the terephthalic acid component units. Specific examples of aromatic dicarboxylic acid component units other than terephthalic acid component units include isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. The diol component units constituting the polyester may contain small amounts of other diol component units in addition to the ethylene glycol component units. Specifically, other diol component units other than ethylene glycol component units include propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, cyclohexanediol, cyclohexanedimethanol, 1,4-bis (β-hydroxyethoxy)benzene, 1,3-bis(β-hydroxyethoxy)benzene, 2,2-bis(4
-β-hydroxyethoxyphenyl)propane,
Diol component units having 3 to 20 carbon atoms such as bis(4-β-hydroxyethoxyphenyl)sulfone, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, and Polyethylene glycol, polypropylene glycol, with a molecular weight of 300 to 10,000,
Examples include polyalkylene glycol units such as polytetramethylene glycol. In addition to the aromatic dicarboxylic acid component units and the diol component units, the polyester may also contain a small amount of a polyfunctional compound as required. Specifically, the polyfunctional compound component units include trimellitic acid, trimesic acid,
Aromatic polybasic acids such as pyromellitic acid, 3,3',5,5'-tetracarboxydiphenyl, aliphatic polybasic acids such as butanetetracarboxylic acid, phloroglucin, 1,2,4,5-tetra Examples include aromatic polyols such as hydroxybenzene, aliphatic polyols such as glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol, and oxypolycarboxylic acids such as tartaric acid and malic acid. Further, the polyester may contain a small amount of an oxycarboxylic acid compound such as p-hydroxybenzoic acid in addition to the aromatic dicarboxylic acid component unit, the diol component unit, and the polyfunctional compound. The composition of the constituent components of the polyalkylene terephthalate is such that the content of terephthalic acid component units is usually
The content of aromatic dicarboxylic acid component units other than terephthalic acid component units is usually 0 to 10 mol%, preferably 0 to 7 mol%. The content of ethylene glycol component units is usually 35 to 51 mol%, preferably 40 to 51 mol%.
The content of diol component units other than ethylene glycol component units is usually 0 to 15 mol%, preferably 0 to 10 mol%.
and the content of polyfunctional compound component units are usually in the range of 0 to 10 mol%, preferably 0 to 8 mol%. In addition, the intrinsic viscosity [η] of the polyester (50°C in p-chlorophenol solution)
The value measured at is usually
The temperature range is from 40 to 140°C, preferably from 50 to 120°C. [About component (B)] The compound (B) to be blended into the polyester composition of the present invention is a sulfur-containing polyester condensate selected from the group of (b ₁ ) to (b ₂ ), and in addition to each alone, Those two types may be used together. In the compound represented by the general formula (HY-R) ₂ S, R is a hydrocarbon group selected from the group consisting of aliphatic, alicyclic, aromatic and combinations thereof having two or more carbon atoms, The two R's may be the same or different. The aliphatic hydrocarbon group usually has 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms, and includes not only chain but also branched groups. The alicyclic hydrocarbon group preferably has 10 or less carbon atoms, particularly preferably 4 to 6 carbon atoms, and the ring may be substituted with an alkyl group. Further, in the aromatic hydrocarbon group, one or more lower alkyl groups may be substituted on the benzene nucleus. R may be any combination of these hydrocarbon groups. In addition, Y represents oxygen or sulfur, and two Y
may be associated with each other. Specifically, the compounds represented by the general formula (HY-R) ₂ S include thiodiethanol, thiodipropanol, thiodibutanol, 2-hydroxypropylsulfide, thiodicyclohexanol, thiodicyclopentanol, Thiodiphenol, 2
- Methyl captoethyl sulfide, thiodibenzyl alcohol, thiodiophenol, etc. can be mentioned. The organic dicarboxylic acids that can be condensed with the compound represented by the general formula () to form the condensate (b ₁ ) include a wide range of organic dicarboxylic acids such as aliphatic organic dicarboxylic acids, aromatic organic dicarboxylic acids, and alicyclic organic dicarboxylic acids. Dicarboxylic acids can be used. The aliphatic organic dicarboxylic acid preferably has 2 to 20 carbon atoms, such as adipic acid, sebacic acid, or isomers thereof. Examples of aromatic organic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. As the alicyclic organic dicarboxylic acid, for example, cyclohexanedicarboxylic acid can be used. As a first step for condensing with the compound represented by the general formula () to form a condensate (b ₂ ),
The organic monomer condensed with the compound represented by () above is one having two alcoholic or phenolic hydroxyl groups. In this case, one molecule of the monomer may have two alcoholic hydroxyl groups, it may similarly have two phenolic hydroxyl groups, and furthermore one molecule may have one alcoholic hydroxyl group and one phenolic hydroxyl group. It may also have a phenolic hydroxyl group. Examples of these organic monomers include the compound represented by the general formula () itself, as well as ethylene glycol, diethylene glycol, and
Alkylene glycols such as propylene glycol, 1,4-butanediol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, divalent biphenols such as hydroquinone, resorcinol, and bisphenol A, p-methylolphenol, m-methylolphenol, Examples include hydroxyalkylphenols such as salicyl alcohol, dihydroxycycloalkanes, and the like. Furthermore, in the second step, the organic dicarboxylic acid that is further condensed with the compound produced in the first step to form the condensate (b ₂ ) is the same as that used to form the condensate (b ₁ ). Organic dicarboxylic acids are fine. Compound (B) per 100 parts by weight of polyester (A)
The blending ratio of is required to be 0.1 to 15 parts by weight, preferably 0.5 to 10 parts by weight. If the proportion of compound (B) is less than the above range, the low-temperature mobility of the polyester molecules will not be improved, whereas if it is too large, the mechanical properties will be poor. [About component (C)] Any known crystallization promoter (C) can be used as the crystallization promoter (C) to be added to the polyester composition of the present invention. For example, solid inorganic compounds such as talc, clay, salts of organic carboxylic acids such as caproic acid, stearic acid, montanic acid, benzoic acid, terephthalic acid, e.g. sodium, potassium salts, organic polymers with pendant carboxyl groups. , for example metal salts of copolymers of olefins or aromatic olefins with unsaturated carboxylic acid compounds such as acrylic acid or methacrylic acid or maleic anhydride. Of course, these may be used in combination. Among these crystallization promoters, metal salts of copolymers of aromatic olefins and α,β unsaturated carboxylic acids are particularly preferred. Further, more preferably, an ionic random copolymer is used. This random copolymer is
It consists of the following three component units (C ₁ ), (C ₂ ), and (C ₃ ), or it consists of four component units to which the component unit (C ₄ ) is added. The ( _C1 ) component unit is a monoolefin component unit, preferably 50 to 99.8 mol% in the copolymer.
It accounts for 60-99 mol%. The monoolefin forming the (C ₁ ) component unit is α-
Olefin, styrene, and styrene substituted with a lower alkyl group having 4 or less carbon atoms are preferably used. Examples include ethylene, propylene, 1-butene, 1-pentene, 4
-α-olefins such as methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, styrene, α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p - Styrene or substituted styrene such as vinyltoluene can be exemplified. ( _C2 ) component unit is acrylic acid or methacrylic acid component unit, 0.2 to 50 mol% in the copolymer,
Preferably it accounts for 1 to 40 mol%. The (C ₂ ) component unit is formed from acrylic acid and/or methacrylic acid. The ( _C3 ) component unit is an acrylate or methacrylate component unit, and accounts for 0.2 to 50 mol%, preferably 1 to 40 mol%, in the copolymer. ( _C3 )
The component units are formed from acrylates and/or methacrylates. Examples of acrylates and methacrylates include alkali metal salts, alkaline earth metal salts of acrylic acid or methacrylic acid,
Zinc salts and the like are preferably used, for example, lithium acrylate, sodium acrylate, potassium acrylate, magnesium acrylate, calcium acrylate, barium acrylate, zinc acrylate, sodium methacrylate, potassium methacrylate, magnesium methacrylate, Examples include calcium methacrylate, barium methacrylate, and zinc methacrylate. The (C ₄ ) component unit is an alkyl acrylate or alkyl methacrylate component unit, and can occupy a proportion of 50 mol% or less, preferably 40 mol% or less in the copolymer. Examples of the alkyl acrylate or alkyl methacrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Among the ionic random copolymers mentioned above, the aliphatic ionic random copolymers preferably have a melt index of 0.1 to 100 at 190°C and a load of 2160 g.
and more preferably in the range of 0.5 to 50. of the aliphatic ionic random copolymer.
Vicat softening point is 20-150℃ preferably 40-150℃
It is in the range of 100℃. The aliphatic ionic random copolymer can be produced by conventional high-pressure radical polymerization techniques. Commercial products can also be used as these copolymers, such as Himilan H1554,
H1555, H1601, H1605, H1650, H1652,
Examples include H1706, H1707, H1855, and H1856 (manufactured by Mitsui Dupont Chemical Co., Ltd.). Moreover, among the above ionic random copolymers,
The aromatic ionic random copolymer preferably has a number average molecular weight (n) of 1000 to 300000, more preferably 2000 to 300000, as measured by gel permeation chromatography (GPC).
In the range of 200000. Further, the molecular weight distribution is preferably in the range of 1.2 to 15, more preferably in the range of 1.5 to 10. If the number average molecular weight or molecular weight distribution of the aromatic ionic random copolymer is out of the above range, the purpose of blending the ionic copolymer tends to be weakened in any case. The softening point of the aromatic ionic random copolymer used in the present invention is in the range of 150 to 260°C, preferably 190 to 240°C. (Meth)acrylic acid component unit (C ₂ ) in the aromatic ionic random copolymer used in the present invention
Assuming that the content of is x ₁ mol% and the content of (meth)acrylate component units (C ₃ ) is x ₂ mol%,
The aromatic ionic random copolymer used in the present invention usually satisfies the following general formula: x ₂ −0.3x ₁ ≦16, preferably x ₂ −0.3x ₁ ≦14. Furthermore, the amount of the aromatic ionic random copolymer used in the present invention is expressed in g/(100 ml solvent) after stirring for 16 hours in a solvent at room temperature, and is usually 2 to 2 g/(100 ml solvent) for methanol. 20g/
It exhibits solvent solubility in the range of 100 ml, preferably 3 to 15 g/100 ml, and usually 0.1 g/100 ml or less in water. The aromatic ionic random copolymer used in the present invention can be produced, for example, by the method shown below. That is, a monomer mixture consisting of the aromatic monomer made of the styrene or lower alkyl group-substituted styrene, the (meth)acrylic acid, and optionally the (meth)acrylic acid ester is mixed with a dispersant and polymerized in water. The copolymerization is carried out by suspending in the presence of an initiator and stirring at a temperature of usually 50 to 100°C. The proportion of the monomer mixture to water during the copolymerization reaction is usually 10 to 50 parts by weight, preferably 15 to 40 parts by weight, per 100 parts by weight of water.
Parts by weight range. Gelatin as a dispersant,
Polyacrylic acid, sodium polyacrylate, and polyvinyl alcohol are preferably used, and the proportion used is usually 0.1 parts by weight per 100 parts by weight of the monomer mixture.
It ranges from 0.2 to 2.0 parts by weight, preferably from 0.2 to 1.5 parts by weight. Furthermore, as the polymerization initiator, benzoyl peroxide, azobisisobutyronitrile, and diuroyl peroxide are preferably used, and the proportion thereof is usually 0.1 to 100 parts by weight of the monomer mixture.
2.0 parts by weight, preferably in the range of 0.2 to 1.5 parts by weight. After the copolymer produced after the polymerization reaction is separated, the copolymer is obtained by washing with water and drying. A basic aqueous solution is added to a solution of the copolymer dissolved in a solvent such as benzene, toluene, or xylene.
The (meth) in the copolymer is removed by azeotropic removal of water at a temperature of 50 to 150℃
The ionic random copolymers used in the present invention can be produced by partially neutralizing the acrylic acid component units. The neutralization rate at that time is usually 30 to 100 mol%, preferably 50 to 75%.
It is preferable that the content of the (meth)acrylic acid component unit (C ₂ ) is adjusted within the range of mol % and that the content of the (meth)acrylic acid component unit (C 2 ) is within the above range. Further, a mixture of copolymer powder obtained by a copolymerization reaction and a base is processed under melt-kneading conditions using an extruder or the like, and the neutralization rate at that time is adjusted to be within the above range, and ( The aromatic ionic random copolymer used in the present invention can also be obtained by neutralizing so that the meth)acrylate component unit (C ₂ ) falls within the above range. The above crystallization accelerator (C) is polyester (A)
0.05 to 15 parts by weight per 100 parts by weight, preferably
It is blended in an amount of 0.1 to 10 parts by weight. If the amount is less than 0.05 parts by weight, the effect of promoting crystallization by the additive will not be sufficient, and if it is more than 15 parts by weight, the mechanical properties of the composition will deteriorate. [Other ingredients] The polyester of the present invention can be blended with various reinforcing fillers that have conventionally been blended into polyesters within a range that does not impair its practicality. For example, diatomaceous earth, calcium carbonate, silica,
Reinforcing fillers such as silica alumina, alumina, carbon mica, titanium oxide, carbon fiber, glass fiber, and aramid fiber can be blended. The proportion of this reinforcing filler is in the range of 0 to 100 parts by weight, preferably 20 to 80 parts by weight. Furthermore, the polyester of the present invention can also be blended with various compounding agents or additives that have conventionally been blended into polyesters, within a range that does not impair its practicality. For example, various plasticizers such as ester (including polyester) and ether (including polyether), lubricants, surfactants, thickeners such as pentaerythritol, trimellitic acid, and pyromellitic acid, flame retardants, and ultraviolet stabilizers. , antioxidants, mold release agents, colorants, etc. The blending ratio of these compounding agents or additives is appropriate. Furthermore, various other polymers such as polyolefins, olefin copolymers or modified polymers thereof, polystyrene, polyamides, polycarbonates, polyacetals, polysulfones,
Polyphenylene oxide, fluororesin, silicone resin, epoxy resin, etc. may be blended. The polyester composition of the present invention can be obtained by mixing a polymer mixture consisting of each essential component and, if necessary, compounding agents and additives, and melt-kneading the mixture according to a conventionally known method. . [Example] Next, the present invention will be specifically explained using Examples. In addition, in the examples, the molding and evaluation of the polyester compositions were performed by the following method. Press Molding A rapidly cooled press sheet having a shape of 15 cm x 10 cm x 0.2 cm was produced from the dried polyester composition using a press molding machine (molding temperature: 290°C). Injection molding Using an injection molding machine model IS-35P manufactured by Toshiba Machinery Co., Ltd., a sample for bending test with a thickness of 0.2 cm was prepared at a mold temperature of 70°C. Bending test Width 1.27cm, length 6.35mm cut from press sheet
A rectangular test piece of cm or an injection molded test piece of the same shape was tested using an Instron tensile tester model 1122 at 23° C. and at a crosshead speed of 5 mm/min. Suitability as crystallization rate Using a rectangular test piece with a width of 1.27 cm and a length of 2 cm cut from a press sheet or an injection molded sample, the temperature dependence of the elastic modulus was measured using a DuPont Dynamik Mechanical Analyzer Model 981. It was measured. The ratio E ₁₀₀ /E ₃₀ of the elastic modulus at 100° C. (E ₁₀₀ ) to the elastic modulus at 30° C. (E ₃₀ ) was used as an index representing suitability as a crystallization rate. That is, the larger this value is, the higher the crystallization rate is, and the better the blend. Furthermore, the heat resistance and volatility of the plasticizer, which is one of the components of the polyester composition, was evaluated by the following method. Heat resistance and volatility (Tm, Td ₀ , Td ₅ , measurement of weight loss upon heating) Tm (melting point) was measured using a differential calorimeter (abbreviated as DSC, using a model manufactured by PerkinElmer). In addition, using a thermogravimetric analyzer (abbreviated as TGA, using a model made by PerkinElmer), Td ₀ (weight loss onset temperature), Td ₅ (5% weight loss temperature), and weight when held at 156°C for 3 hours were measured. The rate of decrease was measured. This weight loss rate is a measure of the volatility of the plasticizer. Also, Tm, Td ₀ and Td ₅ are
This indicates the heat resistance of the plasticizer. The sulfur-containing polyester condensate (component B) and crystallization accelerator (component C) used in the examples and comparative examples are shown below. B-1 to B-5 used as B component in Table 1
The structure and physical properties of In addition, in Table 1, thiodiethanol adipic acid polyester B-1
was synthesized as follows. 500 with agitator
16.7g of thiodiethanol and toluene in a mlml reactor
100 ml and 200 ml of pyridine were charged, and the mixture was cooled to 0° C. while stirring in a nitrogen atmosphere. Next, add 25 g of adipic acid chloride and 50 ml of toluene using a dropping funnel.
The mixture was added dropwise over 30 minutes, and the reaction was carried out at 0° C. for 1 hour and at room temperature for 3 hours. After washing the reaction mixture with water, the solvent was distilled off under reduced pressure. The product was purified by recrystallization using an acetone/hexane (8/2) mixed solvent. Yield 28g (yield 88%) Various sulfur-containing polyesters B2 to B5 were synthesized according to the above example. In addition, C-1~ used as component (C) in Table 2
The composition and physical properties of C-6 are shown.

【table】

【table】

【table】

[Table] Examples 1 to 9 and Comparative Examples 1 to 5 Polyethylene terephthalate (component A) with an intrinsic viscosity of 0.65 dl/g (o-chlorophenol solution at 25°C) and various sulfur-containing polyester compounds (component B, see Table 1) ) and crystallization accelerator (component C,
(see Table 2) in the proportions shown in Table 3, then use a 20 mmφ extruder (Dulmage type screw, full flight type screw when glass fiber is blended, L/D = 28). and melt-mixed. Table 3 shows the results of examining the physical properties of the polyester composition thus obtained.

【table】

Claims (1)

[Scope of Claims] 1. Condensation of a sulfur-containing polyester selected from the following group (b ₁ ) to (b ₂ ) with respect to 100 parts by weight of a substantially linear polyester (A) containing ethylene terephthalate as a main constituent unit. substance (B) in the range of 0.1 to 15 parts by weight, and crystallization promoter (C) in the range of 0.05 to 15 parts by weight.
A polyester composition characterized in that the content is within a range of parts by weight. (b ₁ ) General formula () (HY-R) ₂ S () (However, two R are homologs selected from the group of aliphatic, alicyclic, aromatic and combinations thereof having two or more carbon atoms. A sulfur-containing polyester condensate derived from a compound having one or different hydrocarbon groups (two Y's being the same or different and representing oxygen or sulfur) and an organic dicarboxylic acid. (b ₂ ) A sulfur-containing polyester condensate derived from an organic dicarboxylic acid and a compound selected from the group of condensates of the compound represented by the general formula () and an organic monomer having two hydroxyl groups.