JPH1143593A - Thermoplastic polyester resin composition and molded article thereof - Google Patents

Abstract

(57) [Problem] To provide a thermoplastic polyester resin composition having excellent heat shock resistance and good physical properties and mechanical properties, and a molded article thereof. A terminal carboxyl group concentration comprising the following components (A), (B) and (C) and a compounding ratio is 30 equivalent /.
A thermoplastic polyester resin composition weighing 10 ⁶ g or less and a molded product thereof. (A) 100 parts by weight of a thermoplastic polyester (B) 1 to 120 parts by weight of a glass fiber (C) 1 to 50 parts by weight of a polyolefin rubber having a carboxyl group and / or a hydroxyl group-reactive group

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester resin composition having excellent heat shock resistance and good physical and mechanical properties, and a molded product thereof.

[0002]

2. Description of the Related Art Thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate are widely used in various applications such as automobile parts, electric and electronic equipment parts by utilizing their excellent mechanical and physical properties. Have been. However, thermoplastic polyesters
It has a drawback in that it retains physical properties when exposed to both high and low temperatures alternately, that is, has poor heat shock resistance. In particular, heat shock resistance is required for applications such as inserting a metal or sealing a metal, such as a coil bobbin of a motor for electric equipment or a home appliance. Conventionally, to meet this requirement, inorganic fillers such as glass fiber, mica, talc, etc. have been added to polyester in large amounts, or rubber components have been tried to solve this, but this is not a definitive solution. However, it has been difficult to apply the above-mentioned application fields. The rubber component can follow the difference in thermal expansion between the rubber component and the metal, but cannot maintain strength and rigidity, which are excellent properties of polyester. Further, if a large amount of an inorganic component is added for the purpose of maintaining strength and rigidity, adverse effects such as deterioration of the appearance of a molded product occur.
Therefore, there has not yet been obtained any material that can satisfy this requirement.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition which maintains the excellent mechanical properties of a thermoplastic polyester and has excellent heat shock resistance.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the two components of glass fiber and rubber component are contained in a specific amount, and the terminal carboxyl group of the thermoplastic polyester after mixing is mixed. It has been found that by specifying the base concentration (hereinafter referred to as AV), a resin composition having excellent heat shock resistance and excellent physical and mechanical properties can be obtained, and finally the present invention has been completed. It has arrived.

That is, the present invention provides the following component (A):
It is a thermoplastic polyester resin composition having a terminal carboxyl group concentration comprising (B) and (C) and a compounding ratio of 30 equivalents / 10 ⁶ g or less. (A) 100 parts by weight of a thermoplastic polyester (B) 1 to 120 parts by weight of a glass fiber (C) 1 to 50 parts by weight of a polyolefin rubber having a carboxyl group and / or a hydroxyl group-reactive group

Hereinafter, the present invention will be described in detail. The thermoplastic polyester (A) used in the present invention generally includes polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate, polybutylene naphthalate and the like. An aliphatic dicarboxylic acid; at least one selected from alicyclic dicarboxylic acid components such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalene 1,4 or 2,6-dicarboxylic acid;
The heat of the glycol component is at least one selected from aliphatic glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, neopentylene glycol and cyclohexane dimethanol, and diols such as polyethylene glycol and polytetramethylene glycol. It is a thermoplastic polyester resin or a thermoplastic copolymer polyester resin. Preferably, a thermoplastic polyester resin comprising 80 mol% or more of ethylene terephthalate or butylene terephthalate repeating unit or a combination thereof is used.

The thermoplastic polyester used in the present invention
AV of resin is benzyl alcohol / chloroform mixture
Dissolve in solvent (5/5 volume ratio)
Titrate with potassium hydroxide / ethanol solution as indicator
Calculated and the value is 30 equivalent / 10⁶g or less, preferably 25
Equivalent / 10⁶g or less, more preferably 20 equivalent / 10 ⁶
g or less.

The thermoplastic polyester has an AV of 30 equivalents /
Means for controlling the amount to 10 ⁶ g or less include polymerization time, polymerization temperature,
Type and amount of catalyst, alkali metal compounds, methods such as the addition of additives such as alkaline earth metal compounds,
Oxazoline compounds such as 2,2 ′-(1,3-phenylene) bis-2-oxazoline and 2,2′-methylenebis (2-oxazoline), N, N′-bis (2,6-diisopropylphenyl) carbodiimide, Poly (1,3
A method of adding a terminal blocking agent such as a carbodiimide compound such as (5-triisopropylbenzene) polycarbodiimide and / or a resin having a reactive group such as a modified polyolefin can be employed.

The thermoplastic polyester resin used in the present invention usually has an intrinsic viscosity of 0.4 or more measured at 30 ° C. with a phenol / tetrachloroethane mixed solvent (6/4 weight ratio). 0.5 or more, more preferably 0.55 or more.

[0010] The glass fiber (B) used in the present invention is not particularly limited as long as it is generally used for resin reinforcement, but the diameter is 20 µm or less, preferably 15 µm.
Hereafter, more preferably 10 μm or less is used. For example, a long fiber type (roving) or a short fiber type (chopped strand) can be selected and used. Further, the glass fiber may be treated with a sizing agent such as polyvinyl acetate and polyester, a coupling agent such as a silane compound and a boron compound, and other surface treatment agents.

In the present invention, the blending amount of the glass fiber (B) is 1 to 120 parts by weight, preferably 5 to 100 parts by weight, more preferably 10 to 80 parts by weight based on 100 parts by weight of the thermoplastic polyester (A). Department. If the amount is less than 1 part by weight, the reinforcing effect by the glass fiber is insufficient, and
Excessive parts by weight are not preferred because the fluidity of the composition becomes extremely poor.

The polyolefin rubber (C) used in the present invention is a homopolymer of an ethylene hydrocarbon such as polyethylene, polypropylene or polybutene-1, or a copolymer of ethylene and α-olefin (ethylene-propylene copolymer). Copolymer, ethylene-propylene-diene terpolymer, ethylene-butene-1 copolymer, etc.) Copolymer of ethylene and vinyl compound (ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene -Acrylic acid ester copolymers, ethylene-methacrylic acid copolymers, etc.). These are used alone or as a mixture. In the present invention, those having a reactive group are preferred for compatibility with the polyester. Specifically, glycidyl esters of α, β-unsaturated acids and N, N-dimethylaminoethyl Those having a reactive group such as esters, phenyl esters, and stilbene-α, β-dicarboxylic acid, maleic acid, and maleic acid diphenyl ester may be copolymerized. In addition, you may mix | blend the polyolefin rubber which does not have a reactive group for compatibility with polyester, and the compatibilizer of polyester and olefin.

The compounding amount of the polyolefin rubber (C) is 1 to 5 with respect to 100 parts by weight of the thermoplastic polyester (A).
0 parts by weight, preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight. If the amount is less than 1 part by weight, the effect of heat shock resistance is small, and if it exceeds 50 parts by weight, the rigidity and heat resistance of the product are significantly reduced, and the excellent properties of the thermoplastic polyester are impaired.

In the composition of the present invention, a flame retardant, a flame retardant auxiliary, an inorganic filler, a core material,
You may mix | blend a stabilizer, an antioxidant, a light stabilizer, a mold release agent, a foaming agent, an antistatic agent, an anticancer agent, etc. The composition thus obtained can be easily molded by known molding methods such as injection molding and extrusion molding as appropriate, and the resulting molded article retains the original excellent properties of thermoplastic polyester,
It has the heat shock resistance required according to the product.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below, but the present invention is not limited thereto. As the component (A), a polyethylene terephthalate resin having an intrinsic viscosity of 0.5 to 0.7 and / or an intrinsic viscosity of 0.1.
Using a polybutylene terephthalate resin of 6 to 0.9,
A glass fiber (chopped strand having a fiber diameter of 10 μm and a fiber length of 3 mm) as the component (B), and an ethylene-glycidyl methacrylate copolymer (a glycidyl methacrylate component of 10 to 20% by weight) as a component (C) in a prescribed amount. After pre-mixing, the mixture is put into a hopper of a twin-screw extruder and melt-kneaded at a cylinder temperature of 240 to 280 ° C to obtain the composition of the present invention (compound chips).

This compound chip is used for
After drying at 2 ° C. for 2 to 6 hours, a metal insert molded product can be obtained by press-fitting a metal into the molded product, such as injection molding or extrusion molding using a metal insert. Power window,
A gear case such as a sunroof may be used. Also, the composition of the present invention is first molded by injection molding or extrusion molding,
For example, as a use of a molded product obtained by heating and pressing a ceramic plate using a silicon-based adhesive, an upper frame of an electromagnetic cooker and the like can be mentioned.

[0017]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In addition, the heat shock property in the examples was determined by the heat cycle which was obtained by the following method. Heat shock property: A molded product obtained by insert-molding a cylindrical stainless steel having a diameter of 36 mm and a height of 25 mm with a uniform thickness of 2 mm in resin thickness is treated at -40 ° C for 1 hour, and then at 180 ° C for 1 hour. The heat shock test for the treatment was repeated, and the cycle up to the occurrence of cracks by visual judgment was measured. In addition, if this heat shock is less than 50 times, it cannot be put on the market.

Examples 1-4, Comparative Examples 1-4 As component (A), polyethylene terephthalate resin (intrinsic viscosity 0.62) (hereinafter abbreviated as PET), polybutylene terephthalate resin (intrinsic viscosity 0.80) ( Below P
BT) as a component (B), glass fiber (chopped strand having a fiber diameter of 10 μm and a fiber length of 3 mm) (hereinafter abbreviated as GF), and glass beads having a particle diameter of 18 μm (hereinafter abbreviated as GB) as a comparative example. Was preliminarily mixed as a component (C) with an ethylene-glycidyl methacrylate copolymer (glycidyl methacrylate component 15 wt%) (hereinafter abbreviated as GMA-PE) in a composition shown in Table 1, and then charged into a hopper of a twin-screw extruder. Then, the mixture was melt-kneaded at a cylinder temperature of 265 ° C. to obtain compound chips. After drying the compound chip at 140 ° C. for 4 hours, a metal insert molded product for heat shock measurement was molded by an injection molding machine. The results are also shown in Table 1.

[0019]

[Table 1]

[0020]

As is apparent from Table 1, glass fiber and olefin rubber are blended with thermoplastic polyester,
Further, it is found that only when the AV of the polyester is 30 equivalents / 10 ⁶ g or less, a material excellent in heat shock resistance can be obtained while maintaining excellent mechanical properties of the thermoplastic polyester. Therefore, by adopting the present invention, it is possible to expand the field of application to such uses in which thermal cycling is used, and it is extremely useful especially in applications where a metal is inserted into thermoplastic polyester or a metal is sealed. It is important to contribute to the industry.

Claims (3)

[Claims] 1. The concentration of a terminal carboxyl group comprising the following components (A), (B) and (C) and a compounding ratio is 30 equivalents /
A thermoplastic polyester resin composition weighing 10 ⁶ g or less. (A) 100 parts by weight of a thermoplastic polyester (B) 1 to 120 parts by weight of a glass fiber (C) 1 to 50 parts by weight of a polyolefin rubber having a carboxyl group and / or a hydroxyl group-reactive group 2. A molded article obtained by inserting a metal into the resin composition according to claim 1. 3. A molded product obtained by bonding a ceramic plate to the resin composition according to claim 1.