JPH11286585A - Thermoplastic polyester resin composition and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic polyester resin composition having excellent flexibility while keeping moldability and mold releasability without losing mechanical strength or heat resistance more than usual thermoplastic polyester elastomer, and to provide a method for producing the resin composition. SOLUTION: This thermoplastic polyester resin composition is obtained by incorporating (C) 1-20 pts.wt. of an olefinic copolymer at least having an epoxy- containing (meth)acrylate component in the molecule and (D) 0.1-2.0 pts.wt. of a crosslinking initiator into totally 100 pts.wt. consisting of (A) 75-5 pts.wt. of a copolymerized polyester resin and (B) 25-95 pts.wt. of EPDM rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoplastic polyester resin composition and a method for producing the same.
More specifically, by dispersing a specific crosslinked rubber component in a copolymerized polyester resin, a more flexible elastomer than conventional block-type thermoplastic polyester elastomers is realized, and at the same time, good moldability and releasability are exhibited. At the very least, heat that can be used in molded products that have been advantageous for conventional rubber products, such as various packings, hoses, telephone wire curled cords, cable covers, bottle stoppers, golf ball skin materials, etc. The present invention relates to a plastic polyester resin composition and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, thermoplastic polyester elastomers (hereinafter referred to as "TPEE") have been used in a wide range of fields because of their good moldability, heat aging resistance and chemical resistance. Because TPEE is a block copolymer composition, it is known to increase the high melting point polyester segment (hard segment) component to increase mechanical strength, but on the other hand, the flexibility of the resin is poor. There is a disadvantage that it will. On the other hand, in order to impart flexibility to the TPEE, it is known to increase the number of low-melting polyester or polyether segment (soft segment) components. There was a problem that the target strength was reduced. In addition, TPEE based on the conventional block type copolymer composition
Thus, there was a limit to lowering the hardness and lowering the elastic modulus, and the price was high. Therefore, attempts have been made to add amorphous polymers typified by rubber to block-type TPEE and crystalline polyesters such as polyethylene terephthalate and polybutylene terephthalate.However, due to poor compatibility, There was a problem that a product having the required elastomer properties could not be obtained.

On the other hand, there has been proposed a method of obtaining a thermoplastic elastomer composition by so-called dynamic crosslinking in which a crystalline polyester and EPDM rubber are kneaded at a high shear rate and crosslinked with a crosslinking agent (Japanese Patent Publication No. 55-14099). No.). However, since crystalline polyester and EPDM rubber are originally incompatible with each other, it is extremely difficult to obtain a uniform and stable microstructure composition by mechanical kneading alone, and the obtained composition is There was a problem that the mechanical properties were insufficient and the product was not practical. Further, as an attempt to solve these problems, a method of improving the compatibility between the crystalline polyester and the EPDM rubber by adding an ethylene acrylic rubber having a polar group capable of reacting with the terminal group of the crystalline polyester as a third component. Has been proposed (JP-A-8-302112). However, since the ethylene acrylic rubber used in this method has a large adhesive property, there is a problem in mold release properties and the like in producing a thermoplastic elastomer.

[0004]

According to the present invention, a rubber component is dispersed in a copolymerized polyester, and this dispersion is not only caused by mechanical kneading, but also by an olefin copolymer having a reactive group as a third component. The union reacts with the terminal group of the copolymerized polyester to improve the compatibility between the copolymerized polyester and the rubber component, and at the same time, performs the internal crosslinking of the rubber component in the presence of a crosslinking initiator, thereby improving the moldability. Another object of the present invention is to provide a thermoplastic polyester resin composition having excellent flexibility without lowering mechanical strength and heat resistance than conventional TPEE while maintaining releasability, and a method for producing the same.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have completed the present invention. That is, the gist of the present invention is as follows. (1) (A) 75 to 5 parts by weight of a copolyester resin and (B) EPDM
(C) 1 to 20 parts by weight of an olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule with respect to 100 parts by weight in total of 25 to 95 parts by weight of rubber.
(D) 0.1 to 2.0 parts by weight of a crosslinking initiator. (2) (A) Copolyester resin, (B) EPDM rubber and (C)
Melt-kneading an olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule
A method for producing a thermoplastic polyester resin composition, comprising reacting the component (A) with the component (C), adding a crosslinking initiator (D), and internally kneading the component (B) by melt-kneading. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Examples of the copolymerized polyester resin which is the component (A) used in the present invention include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, ,Four'
-An aromatic dicarboxylic acid component such as sulfonyldibenzoic acid and an aliphatic dicarboxylic acid component such as adipic acid, azelaic acid and sebacic acid; ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol and 2,2-dimethyltricarboxylic acid; Methylene glycol,
Hexamethylene glycol, decamethylene glycol,
p-xylene glycol, cyclohexane dimethanol,
Poly (ethylene oxide) glycol, poly (1,2-propylene oxide) glycol, poly (1,3-propylene oxide) glycol, poly (tetramethylene oxide)
A random copolymerized polyester comprising a diol component such as glycol, or ε-caprolactone or δ-
A random copolymerized polyester of a lactone such as pivalolactone, the aromatic dicarboxylic acid component and the diol component, an aromatic ether dicarboxylic acid component such as 1,4-bis (4,4'-dicarboxydiphenoxy) ethane and the diol And the like.

The relative viscosity of the above copolymerized polyester is
Using a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio 1/1) as the solvent, temperature 20 ° C, concentration
It is preferably in the range of 1.2 to 1.7 as measured under the condition of 0.5 g / dl. The melting point of the copolymerized polyester is
Usually, it is in the range of 140-250 ° C, but preferably 150-200 ° C.

EPDM of component (B) used in the present invention
The rubber includes a terpolymer of ethylene, propylene and a non-conjugated diene. Further, the non-conjugated diene constituting the terpolymer is 5-ethylidene-2.
-Norbornene, 1,4-hexadiene, 5-methylene-2-norbornene, 1,6-octadiene, 2-methyl-1,4-pentadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-
Examples include 1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, dicyclopentadiene, 1,5-cyclooctadiene, 1-methyl-1,5-cyclooctadiene, and the like.

The olefin copolymer as the component (C) used in the present invention is a polymer compound which exhibits a substantially amorphous state at room temperature, is a thermoplastic and uncrosslinked one, and has a high temperature. (150 ° C. or higher) does not thermally and rapidly crosslink, and contains an epoxy group as a reactive functional group.

Specific examples of the olefin copolymer include a copolymer having an epoxy-containing (meth) acrylate component in the same molecule or a terpolymer having an epoxy-containing (meth) acrylate component and a vinyl acetate component in the same molecule. Copolymers and quaternary copolymers, preferably ethylene / glycidyl (meth) acrylate copolymer, propylene / glycidyl (meth) acrylate copolymer, ethylene / glycidyl (meth) acrylate / vinyl acetate terpolymer Copolymer, propylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, ethylene / propylene / glycidyl (meth) acrylate / vinyl acetate quaternary copolymer, etc. In particular, terpolymers or quaternary copolymers have excellent flexibility. Masui.

The crosslinking initiator used as the component (D) in the present invention is not particularly limited as long as it can be crosslinked at the unsaturated bond site of the EPDM rubber. Specific examples thereof include sulfur, acetyl peroxide, succinic acid peroxide, benzoyl peroxide, m-toluyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, (T-butylperoxy) cyclohexane, t-butylperoxyisopropyl carbonate, 2,2-bis (t-butylperoxy) octane, t-butylperoxyacetate, 2,5-dimethyl-2,5-di (benzoylperoxy) Hexane, t-butylperoxylaurate, di-t-butylperoxyisophthalate, t-butylperoxybenzene, dicumyl peroxide, α,
α'-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl Organic peroxides such as hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide are included.

In the composition of the present invention, the above (A) and (A)
It is necessary that the amount of component (B) be 75 to 5 parts by weight for component (A) and 25 to 95 parts by weight for component (B). (A) component
If it exceeds 75 parts by weight, the performance and flexibility as an elastomer tend to decrease. On the other hand, if the amount of the component (A) is less than 5 parts by weight, the component (A) can no longer be a continuous phase, and melt molding becomes difficult. The amount of the component (C) is the same as that of the component (A).
It is necessary to use 1 to 20 parts by weight based on 100 parts by weight in total with the component (B). If the component (C) is less than 1 part by weight,
Since the reaction with the terminal carboxyl group of the component (A) does not proceed sufficiently, and does not sufficiently serve as a compatibilizer,
The interfacial adhesion between the component (A) and the component (B) becomes insufficient, and physical properties such as mechanical properties tend to decrease. On the other hand, the component (C)
If the amount exceeds 20 parts by weight, the mechanical properties of the composition hardly improve, and only the cost increases, and the surface of the molded article becomes tacky, which is not preferable. Furthermore, the blending amount of component (D) is the sum of components (A) and (B).
0.1 to 2.0 parts by weight is required for 100 parts by weight. When the amount of the component (D) is less than 0.1 part by weight, it does not sufficiently serve as a crosslinking initiator. On the other hand, if the component (D) is 2.0
Exceeding the weight part is not preferable because radicals are generated even at locations other than the unsaturated bond site.

Next, a method for producing the resin composition of the present invention will be described. Although the method of the present invention is not particularly limited, the reaction between the component (A) and the component (C) and the internal crosslinking reaction of the component (B) must be performed during melt-kneading. Here, the internal crosslinking means that the double bond site of the component (B) is added to another double bond site of the component (B) by the component (D) which is a crosslinking initiator. Specifically, the components (A), (B) and (C) are melt-kneaded using a Banbury mixer, a roller kneader, a single-screw or multi-screw extruder or the like, and the components (A) and (C) are kneaded. After reacting the component (A), the component (D) is added and the component (B) is dynamically cross-linked by melt-kneading the component (B), or the component (A) and the component (C) are melt-kneaded (A After sufficiently reacting the terminal carboxyl group of the component and the epoxy group of the component (C), there is a method in which the component (D) is added and the internal crosslinking of the component (B) is dynamically performed by melt-kneading. The former is preferred in terms of productivity.

As for the conditions for melt kneading, it is necessary that the kneading temperature be equal to or higher than the melting temperature of the continuous phase component (A).
It is preferably from 150 to 250 ° C, particularly preferably from 170 to 220 ° C. Further, the residence time of the entire melt kneading is preferably 30 seconds to 15 minutes, and the residence time (kneading time required for crosslinking) after adding the component (D) is preferably 15 seconds to 10 minutes. .

The resin composition may contain various additives such as an antioxidant, a plasticizer, an antistatic agent, an ultraviolet absorber, a coloring agent, a foaming agent, and a crystal nucleating agent in a range that does not impair the characteristics of the present invention. Can be appropriately blended.

[0016]

The thermoplastic polyester resin composition of the present invention comprises:
The component (A) and the component (B) are compatible via the component (C), and the component (B) can be finely dispersed in the component (A). Furthermore, due to internal crosslinking of component (B), component (B)
Even if the volume fraction is higher than the component (A), the component (A) can be a continuous phase. Further, it is presumed that since the component (B) is crosslinked, rubber elasticity (flexibility) is more easily developed, and a composition excellent in compression set, which is important as an elastomer, can be obtained.

[0017]

Next, the present invention will be described more specifically with reference to examples. In addition, the measuring method of each property value in an Example and a comparative example is as follows. (1) Surface hardness Measured according to ASTM-D2240. (2) Tensile strength and elongation Measured according to ASTM-D638. (3) Compression set Measured according to JIS K6301. In addition, this value is an index of the elastomer characteristic,
The smaller the value, the better.

Example 1 Random copolymerized polyester having a terephthalic acid / sebacic acid / tetramethylene glycol = 80/20/100 (weight ratio) as the component (A) (relative viscosity 1.65, melting point 180 ° C.) 50
Parts by weight, EPDM of component (B) (VISTALON 3708, manufactured by EXXON)
50 parts by weight, as the component (C), an olefin-based copolymer which is an ethylene / glycidyl methacrylate / vinyl acetate-based terpolymer (manufactured by Sumitomo Chemical Co., Ltd .: bond fast 7B, glycidyl methacrylate content: 12 wt. %) 5 parts by weight are added, and a twin screw extruder with an inner diameter of 30 mm (PCM-30, manufactured by Ikegai Iron Works)
The components (A) and (C) are reacted and melt-kneaded at a kneading temperature of 200 ° C. and a kneading time of 4 minutes to form a pellet, and then the component (D), 2, Add 0.48 parts by weight of 5-dimethyl-2,5-di (t-butylperoxy) hexine-3 (manufactured by NOF CORPORATION, Perhexin 25B, white powder type) and knead again using a twin-screw extruder at a kneading temperature of 200 ° C. The component (B) was internally kneaded by melt-kneading under the conditions of a time of 1.5 minutes to form pellets. Next, a test piece was prepared from the pellet using an injection molding machine (Mitsubishi Heavy Industries, Model 125/75). Table 1 shows the physical properties of the obtained test pieces.

Examples 2 to 4 and Comparative Examples 1 to 5 The same as Example 1 except that the amounts of the components (A), (B), (C) and (D) were changed as shown in Table 1. To make a test piece. Table 1 shows the physical properties of the obtained test pieces.

[0020]

[Table 1]

The resin compositions obtained in Examples 1 to 4 were able to obtain excellent values in all of physical properties such as surface hardness, tensile strength / elongation, and compression set. In contrast, the comparative example has the following problem.

In Comparative Examples 1 and 2, the compression set was remarkably inferior because no dynamic internal crosslinking was performed, and the component (C) as a compatibilizer was not present. The compatibility between component (A) and component (B) was poor and mechanical properties were poor. Comparative Example 3 had no performance as an elastomer because it was only a copolymerized polyester. Comparative Example 4 was a sample subjected to dynamic internal crosslinking, but the resulting sample was inferior in performance as an elastomer because of a large amount of component (A) serving as a matrix. Comparative Example 5 was inferior in compression set because dynamic internal crosslinking was not performed.

[0023]

According to the present invention, it is possible to easily impart low hardness and flexibility while maintaining the thermoplasticity and moldability of the conventional TPEE. It can also be applied to fields that were advantageous.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 67:02 33:14) (C08L 67/02 23:16 33:14)

Claims (3)

[Claims] 1. A total of 100 parts by weight of (A) 75 to 5 parts by weight of a copolymerized polyester resin and (B) 25 to 95 parts by weight of EPDM rubber, (C) epoxy-containing (meth) in the same molecule. Olefin copolymer having at least an acrylate component 1
A thermoplastic polyester resin composition comprising 20 parts by weight and (D) 0.1 to 2.0 parts by weight of a crosslinking initiator. 2. The olefin copolymer of component (C) is an ethylene / glycidyl (meth) acrylate copolymer, a propylene / glycidyl (meth) acrylate copolymer,
Ethylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, propylene / glycidyl (meth) acrylate / vinyl acetate terpolymer, ethylene / propylene / glycidyl (meth) acrylate / vinyl acetate quaternary 2. The thermoplastic polyester resin composition according to claim 1, comprising an olefin copolymer selected from the group consisting of polymers. 3. A polyester resin (A), EPDM (B)
The rubber and the (C) olefin copolymer having at least an epoxy-containing (meth) acrylate component in the same molecule are melt-kneaded, and the components (A) and (C) are allowed to react with each other.
(D) A method for producing a thermoplastic polyester resin composition, comprising adding a crosslinking initiator and internally kneading the component (B) by melt-kneading.