JPS642622B2 - - 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 a method of blending talc and other various inorganic compounds with the polyester;
Method of blending metal salts of aliphatic or aromatic carboxylic acids, polyalkylene glycol, alkoxy polyalkylene glycol, ethylene (meth)
Methods of incorporating various polymers such as acrylate copolymers, unsaturated polyesters, polyamides, etc. are also known. Among them, a copolymer of ethylene or styrene and salts such as acrylic acid and methacrylic acid was proposed in Japanese Patent Publication No. 26225-1973;
No. 47058, No. 55-47059, and Japanese Unexamined Patent Publication No. 59-15445 propose a technique of blending a filler material with a sodium or potassium salt of an organic polymer having pendant carboxyl groups and an organic ester. Also, JP-A-56-145943, JP-A-56-145943
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. [Problems to be Solved by the Invention] However, although the method of blending these additives can considerably improve the crystallization rate of the polyester, the crystallization rate is not sufficient to satisfy the current demands for high-speed moldability. No improvement in speed has been achieved. 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,
Since polyester molecules become glassy in a short time and their molecular motion is frozen, they cannot be crystallized, and as a result, it is presumed that sufficient heat resistance and mechanical properties cannot be achieved. Based on this idea, the present inventors conducted an intensive search for additives that increase the mobility of polyester molecules at low temperatures, and as a result, found a certain compound [component (B) of the present invention] and a crystallization promoter. The inventors have discovered that the combination of [component (C) of the present invention] is effective, and thereby has effects superior to those of the above-mentioned known techniques, and can solve the above-mentioned problems, and have thus arrived at the present invention. [Means for Solving the Problems] To summarize the present invention, the present invention comprises: 100 parts by weight of a substantially linear polyester (A) containing ethylene _{terephthalate} as a main constituent unit; ₃ ) A polyester composition comprising 0.1 to 15 parts by weight of a compound (B) selected from the group of 3) and 0.05 to 15 parts by weight of a crystallization promoter (C). (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 condensate of a compound having one or different hydrocarbon groups, two Y's being the same or different and representing an enzyme or sulfur) and a compound having two alcoholic or phenolic hydroxyl groups. (b ₂ ) An ester compound derived from the compound represented by the general formula () and an organic acid. (b ₃ ) An ether compound derived from the compound represented by the general formula () and a compound selected from the group of monohydric alcohols or monohydric phenols. 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,
Bis(4-β-hydroxyethoxyphenyl)sulfone, bis(4-hydroxyphenylmethane,
Diol component units having 3 to 20 carbon atoms, such as 2,2-bis(4-hydroxyphenyl)propane, and polyalkylene glycol units, such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, having a molecular weight of 300 to 10,000. I can give an example. 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 unit includes aromatic polybasic acids such as trimellitic acid, trimesic acid, pyromellitic acid, 3,3',5,5'-tetracarboxydiphenyl, and butanetetracarboxylic acid. Aliphatic polybasic acids, phloroglucin, aromatic polyols such as 1,2,4,5-tetrahydroxybenzene, glycerin, trimethylolethane, trimethylolpropane,
Examples include aliphatic polyols such as 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.
The content of ethylene glycol component units is usually in the range of 35 to 51 mol%, preferably 40 to 50.5 mol%, other than ethylene glycol component units. The content of diol component units is usually 0 to 15 mol%, preferably 0 to 10 mol%, and the content of polyfunctional compound component units is usually 0 to 10 mol%, preferably 0 to 8 mol%.
in the range of mol%. In addition, the intrinsic viscosity [η] of the polyester (50
(measured at °C) is usually 0.45 to 2.0 d/g,
It is preferably in the range of 0.50 to 1.8d/g,
The melting point is usually in the range 180 to 280°C, preferably 200 to 270°C, and the glass transition temperature is usually in the range 40 to 140°C, preferably 50 to 120°C. [About component (B)] The compound (B) to be blended into the polyester composition of the present invention is a compound selected from the group of (b ₁ ) to (b ₃ ) described above, and in addition to each alone, two types thereof can be used. The above 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 Rs 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, and thiodicyclopentanol. , thiodiphenol, 2
-mercaptoethyl sulfide, thiodibenzyl alcohol, thiodiophenol and the like. The compound that is condensed with the compound represented by the general formula () to form the condensate (b ₁ ) has two alcoholic or phenolic hydroxyl groups. In this case, one molecule of the compound may have two alcoholic hydroxyl groups, it may similarly have two phenolic hydroxyl groups, and furthermore one molecule may have an alcoholic hydroxyl group and one phenolic hydroxyl group. It may also have a hydroxyl group. These compounds include, in addition to the compound itself represented by the general formula (), alkylene glycols listed later, divalent biphenols such as hydroquinone, resorcinol, and bisphenol A, p-methylolphenol, m-methylolphenol, Examples include hydroxyalkylphenols such as salicyl alcohol, dihydroxycycloalkanes, and the like. Preferred examples of the condensate (b ₁ ) include polythiodiethanol and a condensate of thiodiethanol and alkylene glycol.
Among these, polythiodiethanol is a compound represented by the general formula [] HO-(CH ₂ CH ₂ SCH ₂ CH ₂ -O-) _o H [], where n is preferably 150 to 5, and particularly preferably, 100 to 10. Next, a condensate of thiodiethanol and alkylene glycol will be explained. Examples of the alkylene glycol here include ethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, diethylene glycol, triethylene glycol, etc. Each of these may be co-condensed with thiodiethanol, or may be co-condensed with thiodiethanol. More than one species may be co-condensed with thiodiethanol. In this case, the thiodiethanol component units may be co-condensed in blocks or randomly, but the latter case is more preferred. In addition, the molar content of thiodiethanol component units in the cocondensate is usually 60% or more,
It is preferably 70% or more, and the preferred molecular weight is 800 to 15,000. Next, the ester compound (b ₂ ) will be explained. The alcohol component constituting the ester is a compound represented by the general formula (). As acids that form esters with these alcohols, a wide variety of organic acids such as aliphatic organic acids, aromatic organic acids, and alicyclic organic acids can be used. The aliphatic organic acid preferably has 2 to 2 carbon atoms.
20, such as acetic acid, propionic acid, butyric acid,
Valeric acid, caproic acid, enanthic acid, caprylic acid,
Mention may be made of pelargonic acid, stearic acid or their isomers. Examples of aromatic organic acids include benzoic acid, nitrobenzoic acid, toluic acid, phthalic acid, isophthalic acid, and terephthalic acid, with benzoic acid being particularly preferred. Examples of alicyclic organic acids include cyclohexanecarboxylic acid, cycloheptanecarboxylic acid,
Cyclohexanedicarboxylic acid and the like can be used. Particularly preferable examples of the ester compound (b ₂ ) include dibenzoate of thiodiethanol, dibenzoate of thiodipropanol, dibenzoate of copolymerized ether of thiodiethanol and diethylene glycol, and diacetate of thiodiphenol. be able to. Furthermore, a compound represented by the general formula (),
The ether compound (b ₃ ) derived from a compound selected from the group of monohydric alcohols or monohydric phenols will be explained. Here, monohydric alcohols include aliphatic alcohols, alicyclic alcohols, and arylalkyl alcohols having 1 to 20 carbon atoms. 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. Crystallization accelerator (C) per 100 parts by weight of polyester (A)
It is blended in an amount of 0.05 to 15 parts by weight, preferably 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 Compounding Components] The polyester of the present invention can be blended with various compounding agents or additives that have been conventionally blended into polyesters within a range that does not impair its practicality. For example, diatomaceous earth, calcium carbonate, silica, silica alumina, alumina, carbon mica,
Reinforcing fillers such as titanium oxide, carbon fiber, glass fiber, aramid fiber, various plasticizers such as ester (including polyester) and ether (including polyether), lubricants, surfactants, pentaerythritol, trimellitic acid , thickeners such as pyromellitic acid, flame retardants, ultraviolet stabilizers, antioxidants, mold release agents, and colorants. 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. Heat Resistance Using a rectangular test piece 1.27 cm wide and 2 cm long cut from a press sheet or an injection molded sample, the temperature dependence of the elastic modulus was measured using a Dynamik Mechanical Analyzer Model 981 manufactured by DuPont. The ratio of the elastic modulus (E ₁₀₀ ) at 100°C to the elastic modulus (E ₃₀ ) at 30°C, E ₁₀₀ /E ₃₀ , was used as an index representing heat resistance. T _CH , ΔH _H /ΔH _C Measured using a differential calorimeter (abbreviated as DSC) using a Perkin Elmer model. That is, approximately 5 mg of the sample was weighed from a quenched press sheet or an injection sheet. ,20℃/min
DSC measurements were performed under the conditions of increasing the temperature at 290°C, holding it at 290°C for 5 minutes, and then increasing the temperature at 20°C/min. From the obtained calorific curve, the crystallization temperature T _CH when the temperature was raised, the heat amount ΔH _H determined from the peak area at T _CH , and the heat amount ΔH _C determined from the peak area at the crystallization temperature when the temperature was lowered were measured. The T _CH thus obtained is an indicator of the low temperature mobility of polyester molecules. Further, ΔH _H /ΔH _C is an index of ease of crystallization, and the smaller the value of both T _CH and ΔH _H /ΔH _C , the easier it is to crystallize the polyester. Examples 1 to 12, Comparative Examples 1 to 6 Polyethylene terephthalate with an intrinsic viscosity of 0.65 dl/g, a plasticizer such as a thiodiethanol derivative, and various crystallization promoters were dry blended in the proportions shown in Table 1, and then mixed in a 20 mmφ extruder ( Melt mixing was carried out using a Dalmage type screw or a full flight type screw (L/D=28) when glass fiber was blended. The results of examining the physical properties of the polyester composition thus obtained are shown in the table. In Table 1, (1) (B) component B-1 is polyethylene glycol (polyethylene glycol 4000, manufactured by NOF Corporation)
It is. (2) Component B-2 is thiodiethanol dibenzoate. (3) Component (B) B-3 is a copolymerized ether of thiodiethanol and diethylene glycol, and was synthesized as follows. Add 200g of thiodiethanol, 50g of diethylene glycol, and 0.625g of phosphorous acid to the reactor.
The reaction was carried out at 195° C. for 8 hours while water was distilled off under a nitrogen atmosphere. The reaction was further carried out for 5 hours under reduced pressure of 50 mmHg. The product was a pale yellow liquid polymer. The number average molecular weight measured by GPC (THF solvent, 40°C) was 3600. (4) Component B-4 is thiodipropanol dibenzoate. (5) Component B-5 is thiodiphenol diacetate. (6) Component B-6 is dimethyl ether of thiodiphenol. (7) Component B-7 is 2-mercaptoethyl sulfide dibenzoate. (8) Among the crystallization promoter (C) components, C-1 is talc. (9) Among the components of the crystallization accelerator (C), C-2 is a sodium salt of an ethylene/methacrylic acid copolymer (Surlyn 1605, manufactured by DuPont). (10) Crystallization promoter (C) component C-3 is a sodium salt of styrene/methacrylic acid copolymer and was synthesized as follows. Charge 624 g of styrene, 33.8 g of methacrylic acid, and 920 ml of toluene into a reactor equipped with a stirrer.
After bubbling nitrogen for 15 minutes, the reactor was sealed with nitrogen and the temperature was raised to 100°C. Add 2g of benzoyl peroxide and toluene to the dropping funnel.
After charging 60 ml with nitrogen bubbling for 15 minutes, it was added dropwise to the reactor over about 30 minutes. After the dropwise addition was completed, the above reaction was continued for 4 hours, and then the reaction product was precipitated into a large excess of hexane. The yield of molded polymer was 292 g. GPC (THF solvent,
The number average molecular weight Mn measured at 40°C was 84,000, and the molecular weight distribution Mw/Mn was 1.5. Furthermore, the methacrylic acid content in the produced polymer determined by elemental analysis was 10 mol%. In a reactor equipped with a cooler, add 200 g of the styrene/methacrylic acid copolymer synthesized by the above method.
1200 ml of toluene was charged and the temperature was raised to 100°C.
Using a dropping funnel, an aqueous solution containing 6.18 g of NaOH was added dropwise over 5 minutes, and the mixture was reacted for 4 hours. The reaction solution was precipitated into hexane, and the precipitated polymer was collected. The degree of neutralization of the produced polymer was 75%. (11) C-4 of the crystallization promoter (C) component is sodium benzoate (manufactured by Wako Pure Chemical Industries, Ltd.).

【table】

[Table] Others show the physical properties of the press sheet.
b) Values based on 100 parts by weight of polyethylene terephthalate.

Claims (1)

[Scope of Claims] 1. Substantially linear polyester (A) having ethylene terephthalate as its main constituent unit: 100 parts by weight, Compound (B) selected from the following group (b ₁ ) to (b ₃ ): 0.1 to 15 parts by weight, and a crystallization accelerator (C): 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 condensate of a compound having one or different hydrocarbon groups, two Y's being the same or different and representing oxygen or sulfur) and a compound having two alcoholic or phenolic hydroxyl groups. (b ₂ ) An ester compound derived from the compound represented by the general formula () and an organic acid. (b ₃ ) An ether compound derived from the compound represented by the general formula () and a compound selected from the group of monohydric alcohols or monohydric phenols.