JPH10279674A - Polyester resin and molded product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin improved in thermal aging resistance without detriment to mechanical properties, etc., by selecting a resin based on dicarboxylic acids and glycols, comprising an at least tribasic carboxylic acid, an at least trihydric alcohol and a polyalkylene carbonate and having a specified intrinsic viscosity. SOLUTION: This resin comprises a dicarboxylic acid or an esterifiable derivative thereof (A), a glycol or an esterifiable derivative thereof (B), 0.1-5 mol%, based on the total amount of components A and C, at least tribasic carboxylic acid (C) (including an esterifiable derivative thereof), or 0.1-5 mol%, based on the total amount of components B and C, at least trihydric alcohol (C) (including an esterifiable derivative thereof) and 3-65 wt.%, based on the total amount of components A to C, compound represented by the formula (wherein 2<=m<=6; and 4<=n<=23) and has an intrinsic viscosity of 0.5 dl/g or above as measured in a phenol/tetrachloroethane (1/1) mixed solvent at 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded article such as various bottles, films, sheets, plates, fibers, automobile parts, exterior parts, and housings of office equipment, and a thermoplastic polyester resin used for the molding. It is about.

[0002]

2. Description of the Related Art Polyester block copolymers having a crystalline aromatic polyester unit as a hard segment and an aliphatic polyether unit such as polyalkylene oxide glycol or an aliphatic polyester unit such as polylactone as a soft segment are flexible. Excellent in properties such as elasticity, elasticity, oil and chemical resistance, mechanical properties, high temperature properties, etc., it is suitable for various uses such as various materials such as sheets, films, fibers, industrial materials, automobiles, electric and electronic parts, etc. Used.

[0003]

However, the above-mentioned polyester resins are not sufficient in heat aging resistance.
Therefore, various proposals have been made. For example, JP-A-2
Japanese Patent Application No. 173059 proposes a method of adding a polyamide resin and a sulfur-based antioxidant or a phosphorus-based antioxidant. However, in such a composition, since the added polyamide resin has a higher elastic modulus than the polyester resin, there is a problem that the elastic modulus of the composition after addition is increased and other mechanical properties are changed. The present invention has been made to solve the above problems, and has excellent moldability, flexibility, high heat resistance, chemical resistance, mechanical properties, durability, elasticity and high elastic recovery rate of polyester resin. It is an object of the present invention to provide a polyester resin having improved heat aging resistance without impairing its surface gloss, chemical resistance and the like, and a molded product thereof.

[0004]

Means for Solving the Problems The present inventors have made intensive studies in view of such circumstances, and as a result, by copolymerizing a specific component into a polyester resin, the thermal stability, surface appearance, and mechanical properties have been improved. The inventors have found that an improved resin can be obtained, and have reached the present invention. That is, the polyester resin of the present invention comprises (A) a dicarboxylic acid or an ester-forming derivative thereof, (B) a glycol or an ester-forming derivative thereof, and (C) a polyhydric carboxylic acid, a polyhydric alcohol or a trihydric carboxylic acid or a polyhydric alcohol thereof. In the case of a polycarboxylic acid, the ester-forming derivative is 0.1 to 5 mol% based on the total amount of the components (A) and (C), and in the case of a polyhydric alcohol, the total of the components (B) and (C) Polyester containing 0.1 to 5 mol% of the total amount and (D) a compound having a unit represented by the following general formula in an amount of 3 to 65% by weight based on the total of the components (A) to (C). A resin having a limiting viscosity η measured in a mixed solvent of phenol / tetrachloroethane equivalent at 25 ° C. of 0.5 dl / g or more.

Embedded image (However, an integer of 2 ≦ m ≦ 6, 4 ≦ n ≦ 23) The molded article of the present invention is obtained by molding this polyester resin.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester resin of the present invention essentially contains at least the above components (A) to (D). As the component (A) used in the present invention, an aromatic dicarboxylic acid and its ester-forming derivative as a main acid component are preferred from the viewpoint of heat resistance. As aromatic dicarboxylic acids, terephthalic acid, isophthalic acid, naphthalene-1,
4 or 2,6-dicarboxylic acid, anthracenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-
Examples include diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, and sodium 3-sulfoisophthalate. These ester-forming derivatives include lower alkyl esters, aryl esters, carbonates, acid halides and the like. This aromatic dicarboxylic acid is preferably contained in an amount of at least 80 mol% of all the acid components of the entire polyester resin, and more preferably at least 85 mol%. If the amount of the aromatic dicarboxylic acid component is less than 80 mol%, the mechanical strength of the molded article may be reduced, and the productivity may be reduced. Further, an aliphatic dicarboxylic acid as an acid component other than the aromatic dicarboxylic acid,
Alternatively, these ester-forming derivatives can be contained. In such a case, the content is preferably less than 20 mol%, more preferably less than 15 mol% in the total acid component.
This is because if it is contained in an amount of 20 mol% or more, the mechanical strength of the molded article may be reduced. As the aliphatic dicarboxylic acid used in the present invention, oxalic acid, succinic acid,
Glutaric acid, adipic acid, pimelic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, 1,3 or 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 4,4′-dicyclohexyldicarboxylic acid and the like. Can be

The component (B) used in the present invention is for imparting color tone, transparency, heat resistance, impact resistance and the like, and the following various glycols can be applied. Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, dimer diol, cyclohexanediol, cyclohexanedimethanol, the following general formulas (1) and (2)
And ethylene oxide adducts of these derivatives.

Embedded image (Where X is CH ₂ , C (CH ₃ ) ₂ , C (CF ₃ ) ₂ ,
Indicates any of O, S and SO ₂ and satisfies 1 ≦ n + m ≦ 4. )

Embedded image (Where X is CH ₂ , C (CH ₃ ) ₂ , C (CF ₃ ) ₂ ,
O, S, indicates one of SO _2, R represents an alkyl group of C1 to C5, satisfying 1 ≦ n + m ≦ 4. Among them, an ethylene oxide adduct of bisphenol A having a structure represented by the following general formula (3) is preferable.

Embedded image (Where 1 ≦ n + m ≦ 4 is satisfied)

The component (C) of the present invention is a trivalent or higher polycarboxylic acid, a polyhydric alcohol or an ester-forming derivative thereof. More preferably, it is trivalent to tetravalent. When the valence is less than 3, the obtained resin tends to be insufficient in elasticity. Such trivalent or higher polycarboxylic acids include trimellitic acid, pyromellitic acid and polycarboxylic acids such as anhydrides thereof, and polyhydric alcohols include trimethylolpropane, pentaerythritol,
Glycerin and the like. When the component (C) is a polyvalent carboxylic acid, 0.1 to 0.1 of the total amount of the components (A) and (C).
5 mol%, in the case of polyhydric alcohol (B) component and (C)
The range of 0.1 to 5 mol% in the total amount of the components is preferred. If it is lower than this range, there is no effect of blending, and if it is higher, the reaction tends to be difficult to control due to gelation. More preferably, it is in the range of 0.3 to 2 mol%.

The component (D) of the present invention is a component imparting heat resistance, and is 3 to 6 with respect to the total of the components (A), (B) and (C).
Preferably it is 5% by weight. If the content is less than 3% by weight, the flexibility and rubber elasticity are insufficient, and if it exceeds 65% by weight, the polycondensation reaction tends to stagnate or the moldability tends to deteriorate. A more preferred addition range is 10 to 50% by weight. In the unit in the compound of the component (D), m is 2
The number is preferably 6 or more, and n is preferably 4 or more and 23 or less. If m is less than 2, the mechanical properties of the obtained resin will be insufficient, and if m is greater than 6, the heat resistance will be insufficient. Also, when n is less than 4, mechanical properties of the obtained resin are insufficient, and when n is greater than 23, transparency and appearance may be insufficient. The compound (D) preferably has an average molecular weight of 500 to 2,000. If the average molecular weight is less than 500, the mechanical properties of the obtained resin are insufficient, and if it is more than 2000, the transparency and appearance may be insufficient. The component (D) of the present invention may be added at any time during the polymerization reaction, but is preferably after the completion of the esterification reaction of the components (A) to (C). This is because the component (D) has a carbonate bond and may be randomized by transesterification.

The polyester resin of the present invention can be produced by a well-known direct polymerization method, transesterification method, or the like. The polymerization degree is preferably such that the intrinsic viscosity η measured in a mixed solvent of phenol / tetrachloroethane at 25 ° C. is equal to or more than 0.5 dl / g, and more preferably 0.6 dl / g or more. Is more preferable. If it is less than 0.5 dl / g, the viscosity is low,
There is a tendency that the cooling of the strand is difficult, and the loss at the time of pelletizing tends to be large. Further, as a method of obtaining the molded article of the present invention, injection molding, ordinary molding methods such as extrusion molding,
Conditions can be adopted, and molded articles can be molded for various uses such as pellets, films, sheets, and fibers. A molded article using the polyester resin composition of the present invention may be subjected to various known processing treatments to impart specific performance, or may be blended with an appropriate additive. Examples of the processing include irradiation of ultraviolet rays, α-rays, β-rays, γ-rays, electron beams, etc., corona treatment, plasma irradiation treatment, flame treatment, etc., treatment of resins such as vinylidene chloride, polyvinyl alcohol, polyamide, and polyolefin. Coating, lamination, metal deposition, and the like are included.
Examples of additives include polyether, polyamide, polyolefin, resins such as polymethyl methacrylate, silica, talc, kaolin, inorganic particles such as calcium carbonate,
Examples include pigments such as titanium oxide and carbon black, ultraviolet absorbers, release agents, antistatic agents, and flame retardants.

[0010]

The present invention will be specifically described below with reference to examples. Example 1 668.2 g of terephthalic acid, 301.3 g of ethylene glycol and 3.9 g of trimellitic anhydride were placed in a reaction vessel, and the mixture was heated and stirred at 190 to 225 ° C. for 3 hours to carry out an esterification reaction. Then, the temperature was raised to 245 ° C., 100 g of polyhexamethylene polycarbonate having an average molecular weight of 1,000, and 0.3 g of antimony trioxide as a polymerization catalyst.
Was added to advance the polymerization reaction. The intrinsic viscosity η of the obtained polyester resin measured at 25 ° C. in a mixed solvent of phenol / tetrachloroethane equivalent was 0.74. Using this resin and pellets dried at 80 ° C. for 8 hours and injection-molding ASTM-D638 test pieces at 200 ° C., Shore A hardness, tensile strength and elongation, high-temperature shape retention, molded product appearance (resistance to (Chemical properties).
Table 1 shows the evaluation results. In addition, each evaluation method is as follows. Shore A hardness: based on ASTM-K7215. Tensile strength and elongation: According to ASTM-D638. High-temperature shape retention: Dynamic elastic modulus measurement with DMS shows room temperature and 1
The change in elastic modulus at 70 ° C. was calculated based on the following equation. (Dynamic elastic modulus at 170 ° C.) / (Dynamic elastic modulus at 23 ° C.) ×
100% molded product appearance (chemical resistance): The surface of a sheet having a thickness of 200 μm was rubbed with acetone at 23 ° C., and the change in the appearance was visually evaluated.

Example 2 385.5 g of terephthalic acid,
173.8 g of ethylene glycol and 2.2 g of trimellitic anhydride were placed in a reaction vessel to perform an esterification reaction. Then, 500 g of polyhexamethylene polycarbonate having an average molecular weight of 1000 and 0.2 g of antimony trioxide as a polymerization catalyst were added to proceed the polymerization reaction. The resulting polyester resin had an intrinsic viscosity η = 0.74. Table 1 shows the evaluation results of the resin and the injection molded test piece. Example 3 490.2 g of dimethyl terephthalate, 1,4
-Butanediol 545.9 g, trimethylolpropane 6.8 g, tetra-n-butoxytitanium 0.8 as a catalyst.
34 g was placed in a reaction vessel to perform a transesterification reaction. Next, 400 g of polyhexamethylene polycarbonate having an average molecular weight of 500 was added, and the polymerization reaction was allowed to proceed. The resulting polyester resin had an intrinsic viscosity η = 0.74.
The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

Example 4 Dimethyl terephthalate 49
0.2 g, 545.9 g of 1,4-butanediol, 6.8 g of trimethylolpropane, and 0.34 g of tetra-n-butoxytitanium as a catalyst were placed in a reaction vessel to perform a transesterification reaction. Next, 400 g of polyhexamethylene polycarbonate having an average molecular weight of 2,000 was added, and the polymerization reaction was allowed to proceed. The resulting polyester resin has an intrinsic viscosity η =
It was 0.88. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1. Example 5 Dimethyl naphthalenedicarboxylate 433.
4 g, 274.1 g of ethylene glycol, 12.4 g of trimellitic anhydride, and 0.2 g of manganese acetate as a transesterification catalyst were placed in a reaction vessel to carry out a transesterification reaction. Then, 500 g of polytrimethylene polycarbonate having an average molecular weight of 1,000 was added to phosphorus, 0.04 g of an acid and 0.2 g of germanium dioxide as a polymerization catalyst were added to advance the polymerization reaction. The resulting polyester resin has an intrinsic viscosity η = 0.
60. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 1.

[0013]

[Table 1]

Comparative Example 1 Dimethyl Terephthalate 100
2 g, 772.7 g of ethylene glycol, 5.0 g of trimellitic anhydride, and 0.4 g of manganese acetate as a transesterification catalyst were placed in a reaction vessel and transesterified.
g, and 0.4 g of germanium dioxide was added as a polymerization catalyst to proceed the polymerization reaction. The obtained polyethylene terephthalate had an intrinsic viscosity η = 0.78. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2. Comparative Example 2 Dimethyl terephthalate 879.9 g, 1.4
-980.0 g of butanediol, 3.0 g of trimethylolpropane, 0.4 g of tetra-n-butoxytitanium as a catalyst.
6 g was placed in a reaction vessel to allow transesterification and polymerization to proceed. The resulting polybutylene terephthalate had an intrinsic viscosity η = 0.96. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2.

Comparative Example 3 Terephthalic acid 102.4 g,
46.0 g of ethylene glycol and 1.7 g of trimethylolpropane were put into a reaction vessel, and an esterification reaction was performed. Then, 800 g of polytetramethylene glycol having an average molecular weight of 1,000 was used, and 0.1 g of antimony trioxide was used as a polymerization catalyst.
g was added to proceed the polymerization reaction. The resulting polyester resin had an intrinsic viscosity η = 0.74. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2. [Comparative Example 4] 478.0 g of terephthalic acid, 214.4 g of ethylene glycol and 7.7 g of trimethylolpropane were put into a reaction vessel, and an esterification reaction was carried out. Then, polyhexamethylene polycarbonate having an average molecular weight of 3000 was added to 4 parts.
The polymerization reaction was allowed to proceed by adding 0.2 g of antimony trioxide as a polymerization catalyst. The resulting polyester resin had an intrinsic viscosity η = 0.62. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2. [Comparative Example 5] 478.0 g of terephthalic acid, 214.4 g of ethylene glycol, and 7.7 g of trimethylolpropane were put into a reaction vessel, and an esterification reaction was carried out. Then, 500 parts of polytrimethylene polycarbonate having an average molecular weight of 200 were added.
g of antimony trioxide as a polymerization catalyst was added to advance the polymerization reaction. The resulting polyester resin had an intrinsic viscosity η = 0.96. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2.

Comparative Example 6 Dimethyl Terephthalate 49
1.9 g, 547.9 g of 1,4-butanediol, 3.4 g of trimethylolpropane, and 0.3 g of tetra-n-butoxytitanium as a catalyst were placed in a reaction vessel to carry out a transesterification reaction. The polymerization reaction was allowed to proceed by adding 400 g of methylene glycol. The resulting polyester resin has an intrinsic viscosity η = 0.74.
Met. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2. [Comparative Example 7] 579.0 g of terephthalic acid and 303.1 g of ethylene glycol were placed in a reaction vessel, and after an esterification reaction was carried out, 300 g of polyhexamethylene polycarbonate having an average molecular weight of 1000, and 0.2 g of antimony trioxide as a polymerization catalyst. Was added to advance the polymerization reaction. The resulting polyester resin had an intrinsic viscosity η = 0.74. The results of evaluating this resin in the same manner as in Example 1 are shown in Table 2.

[0017]

[Table 2]

[0018]

The polyester resin of the present invention maintains the excellent physical properties and moldability of the conventional polyester resin,
In addition to being a material with excellent flexibility, it has heat resistance, chemical resistance, high elasticity and high elastic recovery rate, and its physical properties do not decrease even at high temperatures, surface gloss and mechanical properties It has excellent properties such as durability, and can be widely used in, for example, automobile parts, exterior parts, housings of office equipment, and the like in addition to bottles, films, sheets, boards, and fibers.

Claims (2)

[Claims] 1. A method comprising: (A) a dicarboxylic acid or an ester-forming derivative thereof, (B) a glycol or an ester-forming derivative thereof, and (C) a trivalent or higher polycarboxylic acid, a polyhydric alcohol or an ester-forming derivative thereof. In the case of a polyhydric carboxylic acid, 0.1 to 5 mol% of the total amount of the component (A) and the component (C), and in the case of a polyhydric alcohol, 0.1 to 5 mol% of the total amount of the component (B) and the component (C). A polyester resin containing 1 to 5 mol% and (D) a compound having a unit represented by the following general formula, 3 to 65% by weight based on the total of the components (A) to (C). A polyester resin having an intrinsic viscosity η measured in a mixed solvent of phenol / tetrachloroethane equivalents at 25 ° C. of 0.5 dl / g or more. Embedded image (However, 2 ≦ m ≦ 6, 4 ≦ n ≦ 23) 2. A molded article comprising the polyester resin according to claim 1.