JPH05320485A - High-flow thermoplastic resin composition excellent in low-temperature impact resistance - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a thermoplastic resin composition having excellent impact resistance at low temperature and excellent flow processability at injection molding. [Composition] A resin composition comprising a polyester resin, an ABS resin, an epoxy group-containing AS resin, a tetrafluoroethylene resin and a reinforcing filler. [Effect] A thermoplastic resin composition having excellent impact resistance at low temperatures and fluidity processability during injection molding, which is useful in a wide range of fields such as automobile parts and electronic parts, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition excellent in impact resistance at low temperature and flow processability in injection molding, and more specifically, polyester-ABS containing a specific polymer.
The present invention relates to a resin composition.

[0002]

2. Description of the Related Art Polyester resins are used in a wide range of fields such as electric and electronic parts and automobile parts because of their excellent chemical resistance and fluid processability. However, its impact resistance, especially its low notched impact strength, limits its application considerably. Therefore, research was conducted on resin compositions for the purpose of improving the impact resistance of polyester resins.
Method of blending BS resin (Japanese Patent Publication No. 51-25261)
No.), and ABS blended with polyester resin
A method of introducing a functional group into a resin / AS resin to improve the physical properties (JP-A-54-23656 and JP-A-1-163).
No. 249) has been proposed.

[0003]

However, the resin composition obtained by the above method is insufficient in improving the impact resistance at least at low temperature.

[0004]

The inventors of the present invention have diligently studied a method of improving impact resistance at low temperature while maintaining the fluidity of a polyester resin during injection molding. The present invention has been completed by finding that the object can be achieved by blending a polymer and, if necessary, a reinforcing filler in a specific ratio.

That is, the present invention is based on a total amount of 100 parts by weight of the following components (A), (B) and (C): 0.05 to 1.0 part by weight of a tetrafluoroethylene resin (D), for reinforcement. It is a high-fluidity thermoplastic resin composition having an excellent weld strength, which comprises 0 to 100 parts by weight of a filler (E). (A) Polyester resin mainly composed of polyalkylene terephthalate 15 to 85 parts by weight (B) ABS resin 10 to 50 parts by weight (C) Vinyl cyanide monomer (I) 15 to 40% by weight Aromatic vinyl monomer (II) 60 to 84.9 wt% Epoxy group-containing vinyl monomer (III) Polymer obtained by polymerizing 0.1 to 0.4 wt% 3 to 75 parts by weight (D) Tetrafluoroethylene resin 0.05-1.0 parts by weight (E) Reinforcing filler 0-100 parts by weight

The polyester resin (A) mainly composed of polyalkylene terephthalate in the present invention is mainly composed of an aromatic dicarboxylic acid having 8 to 22 carbon atoms and 2 to 2 carbon atoms.
It contains 50% by weight or more of two alkylene glycols or cycloalkylene glycols, and may optionally contain a subordinate amount of an aliphatic dicarboxylic acid such as adipic acid or sebacic acid as a constituent unit. You may include polyalkylene glycol, such as polyethylene glycol and polytetramethylene glycol, as a structural unit. Particularly preferred polyester resins include polyethylene terephthalate and polytetramethylene terephthalate. These polyester resins may be used alone or in admixture of two or more. The amount of polyester resin (A) used is (A), (B)
And 15 to 85 out of 100 parts by weight of the total amount of the component (C)
Parts by weight.

Next, the ABS resin (B) in the present invention is obtained by graft polymerizing a vinyl cyanide monomer and an aromatic vinyl monomer on a rubbery polymer composed of butadiene units. . Examples of the rubbery polymer include copolymers containing 50% or more of polybutadiene units and inferior amounts of styrene units and acrylonitrile units, such as styrene-butadiene copolymer and acrylonitrile-butadiene copolymer.

The content of the rubbery polymer in the graft polymer is preferably 50 to 80% by weight. 50% by weight
If it is less than the above range, the content of the resin component which is not graft polymerized as described below tends to increase, and if it exceeds 80% by weight, it becomes difficult to obtain the ABS resin as a powder. In addition, the content of the resin component not graft-polymerized with the rubber-like polymer is the total resin composition ((A), (B) and (C)).
It is particularly preferable that the total amount is 7% by weight or less in 100 parts by weight). If the amount exceeds 7% by weight, the copolymer composed of vinyl cyanide and aromatic vinyl, which has poor compatibility with the polyester resin, tends to increase.

The vinyl cyanide monomer used in the graft polymerization includes acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile and the like, and these can be used alone or in combination. The proportion of vinyl cyanide monomer in the graft monomer is preferably 15 to 40% by weight. If it is less than 15% by weight, the resulting resin composition tends to be inferior in impact resistance and chemical resistance, and if it exceeds 40% by weight, coloring when forming the obtained resin composition becomes large. The aromatic vinyl monomer used for the graft polymerization is styrene, α
-Methyl styrene, o-methyl styrene, 1,3-dimethyl styrene, p-methyl styrene, t-butyl styrene, halogenated styrene, p-ethyl styrene, etc., and these may be used alone or in combination of two or more. You can The proportion of the aromatic vinyl monomer in the graft monomer is preferably 25 to 85% by weight, and when it is out of these ranges, at least one of impact resistance and moldability is poor. In addition, a poor amount of another copolymerizable vinyl monomer can be copolymerized during the graft polymerization. Examples of the other copolymerizable vinyl monomer include methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, and maleimide monomers such as N-phenylmaleimide, but are not particularly limited thereto. .. These other copolymerizable vinyl monomers are optionally used within the range of up to 35% by weight in the graft monomer.

The amount of ABS resin (B) used is (A),
10 to 5 in 100 parts by weight of the total amount of the components (B) and (C)
It is 0 parts by weight, preferably 10 to 35 parts by weight.
When it is out of the range of 10 parts by weight to 50 parts by weight, at least one of impact resistance and chemical resistance is inferior, which is not preferable. If the amount exceeds 35 parts by weight and is 50 parts by weight or less, the amount of free AS resin that has not been graft-polymerized tends to increase, and a high graft ratio is required to reduce this to 7% by weight or less. The content of the free resin component which is not graft-bonded is obtained as follows. That is, 2.5 g of the graft copolymer was immersed in 90 ml of acetone to prepare 6
After heating at 5 ℃ for 3 hours, use a centrifuge to 1500 rpm
Centrifuge for 30 minutes at. After that, the supernatant is removed, the residue is dried in a vacuum dryer at 65 ° C. for 12 hours, and the dried sample is precisely weighed, and its weight is G (g). Content X (%) of free resin component that is not graft polymerized
(For the graft copolymer) can be determined by the following formula.

[0011]

[Equation 1]

The polymer (C) in the present invention comprises 15 to 40% by weight of vinyl cyanide monomer and 5 of aromatic vinyl monomer.
It is obtained by polymerizing 9.6 to 84.9% by weight and 0.1 to 0.4% by weight of an epoxy group-containing vinyl monomer. The same vinyl cyanide monomer and aromatic vinyl monomer as those used in the ABS resin (B) can be used. The content of vinyl cyanide monomer is 15 to 40% by weight, preferably 15 to 25% by weight, based on the total amount of graft monomers. If it is out of this range, at least one of impact resistance, chemical resistance, and coloring of the molded product will be poor. The content of the aromatic vinyl monomer is 59.6 to 84. based on the total amount of the monomers used in the polymer (C).
It is 9% by weight, and if it is out of this range, impact resistance,
Flow processability during injection molding is reduced. Examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate and glycidyl acrylate, and glycidyl methacrylate is particularly preferable. The content of the epoxy group-containing vinyl monomer is 0.1 to 0.4% by weight based on the total amount of the monomers used in the polymer (C). If it is less than 0.1% by weight, the effect of improving impact resistance is inferior, and if it exceeds 0.4% by weight, the fluidity during molding tends to be low, or the impact resistance tends to be low.

As the polymer (C), inferior amounts of other copolymerizable vinyl monomers can be used in addition to the above monomers. Examples of these monomers include methacrylic acid esters such as methyl methacrylate and maleimide monomers such as 2-vinylpyridine, 4-vinylpyridine and N-phenylmaleimide, but are not particularly limited thereto. Absent. These other copolymerizable monomers are optionally used in the range of up to 35% by weight in the polymer (C). The content of the polymer (C) is 3 to 75 parts by weight, and 3
If it is less than part by weight, the effect of improving impact resistance will be poor, and if it exceeds 75 parts by weight, at least one of chemical resistance and impact resistance will be poor. The polymer (C) had a reduced viscosity η _{SP / C} of 0.5 measured with a 0.2% dimethylformamide solution.
It is preferably 5 or less. If it exceeds 0.55, the flow processability during injection molding tends to be poor.

The amount of the tetrafluoroethylene resin (D) used in the present invention is 0.05 to 1.0 parts by weight based on the total amount of (A), (B) and (C). If it is less than 0.05 part by weight, the effect of improving low temperature impact resistance is poor, and if it exceeds 1 part by weight, extrusion and molding become difficult. The tetrafluoroethylene resin also includes copolymers containing up to 50 wt% ethylene. The average particle size of tetrafluoroethylene resin is 35
In the range of 0 μm to 800 μm, those having a molecular weight of 1,000,000 or more are preferably used. Within this range, low temperature impact resistance is particularly excellent. A commercially available tetrafluoroethylene resin is preferably used.

The resin composition of the present invention is further heat-resistant by adding a reinforcing filler (E), if necessary.
It is possible to improve rigidity and dimensional stability. The reinforcing filler (E) is at least one kind of inorganic fibers such as glass fiber, carbon fiber and the like, wollastonite, talc, mica powder, glass foil, potassium titanate and the like, but is particularly limited to these. It is not something that will be done. Further, these crushed products are also preferably used for the purpose of improving the appearance of the molded product by the obtained resin composition. The amount of the reinforcing filler (E) used is 0 to 100 parts by weight based on 100 parts by weight of the total amount of the components (A), (B) and (C). 10
If it exceeds 0 parts by weight, the resulting resin composition is inferior in impact resistance and surface appearance, so that it is not the object of the present invention.

Further, additives such as modifiers, release agents, stabilizers against light and heat, dyes and pigments can be added to the resin composition of the present invention as needed. As a method for adjusting the thermoplastic resin composition of the present invention, a device such as a Henschel mixer or a tumbler used for blending ordinary resins can be used. Further, for shaping, a device used for ordinary shaping such as a single-screw extruder, a twin-screw extruder, and an injection molding machine can be used.

[0017]

The present invention will be described in more detail with reference to the following examples. In the examples, "part" and "%" mean "part by weight" and "% by weight", respectively. In addition, evaluation of each physical property in an Example was based on the following method. (1) Izod impact strength It was measured according to ASTM D-256 by using a test piece having a notch in post processing in a test piece having a thickness of 6.3 mm. (Measurement temperatures are 23 ° C and -30 ° C.) (2) Heat distortion temperature It was measured according to ASTM D-648 (bending stress 4.
6 kg / cm ² ). (3) Short shot pressure (SS pressure) SS pressure was 1 using M-100 (Meiki Co., Ltd.).
When molding a 00 mm square plate with a thickness of 3 mm at a cylinder temperature of 240 ° C, the minimum moldable pressure is the maximum pressure of the molding machine (20
It is expressed as a percentage with respect to 00 kg · f / cm ² ).

Reference Example Each component used in this example was produced by the following method. Polyester Resin (A) As the polyester resin (A), polytetramethylene terephthalate having an intrinsic viscosity [η] of 1.05 was used. Production of ABS resin (B-1) From 63.5 parts (as solid content) of polybutadiene latex having a solid content of 35% and an average particle size of 0.08 μm, 85% of n-butyl acrylate units and 15% of methacrylic acid units are used. Copolymer latex having an average particle size of 0.08 μm
5 parts (as solid content) was added with stirring, and stirring was continued for 30 minutes to obtain a bloated rubber latex having an average particle diameter of 0.28 μm. The obtained enlarged rubber latex was added to a reaction vessel, and 20 parts of distilled water, 0.2 part of naphthalenesulfonic acid formalin condensate (Demol N: Kao Co., Ltd.), 0.02 part of sodium hydroxide, and Dextrose were added. After adding 0.35 part and raising the temperature in the reactor to 60 ° C, ferrous sulfate 0.3
006 parts and 0.2 parts of sodium pyrophosphate were added, and further 10.5 parts of acrylonitrile, 24.5 parts of styrene, t-
A mixture consisting of 0.2 part of dodecyl mercaptan and 0.12 part of cumene hydroperoxide was continuously added dropwise with stirring for 90 minutes, and then the mixture was kept for 1 hour and cooled. The obtained graft copolymer latex is coagulated with dilute sulfuric acid, washed, filtered and dried to obtain the graft copolymer (B-
1) was obtained. The content of the resin component not graft-bonded in the obtained graft copolymer (B-1) was measured by the above-mentioned method, and was 4%.

Manufacture of ABS resin (B-2): 39 parts (as solid content) of polybutadiene latex having a solid content of 35% and an average particle size of 0.08 μm, 85% of n-butyl acrylate units and 15% of methacrylic acid units. 1 part (as solid content) of a copolymer latex having an average particle form of 0.08 μm was added with stirring, and stirring was continued for 30 minutes to obtain an enlarged rubber latex having an average particle diameter of 0.28 μm. The resulting enlarged rubber latex was added to the reaction vessel,
Further, 50 parts of distilled water, 0.2 parts of demole N, 0.02 parts of sodium hydroxide and 0.35 parts of dextrose were added to raise the temperature in the reaction vessel to 60 ° C., and then ferrous sulfate 0.006
Parts, and 0.2 parts of sodium pyrophosphate were added, and further a mixture of 17.4 parts of acrylonitrile, 42.6 parts of styrene, 0.4 parts of t-dodecyl mercaptan, and 0.24 parts of cumene hydroperoxide was stirred and stirred. After the solution was continuously added dropwise over a period of 1 minute, it was kept for 1 hour and cooled. The obtained copolymer latex was coagulated with dilute sulfuric acid, washed, filtered and dried to obtain a graft copolymer (B-2). The content of the free resin component which was not graft-bonded was 25%.

Production of Copolymer (C-1) 115 parts of distilled water, 1 part of tricalcium phosphate and Demol P
0.001 part (manufactured by Kao Corporation) was placed in a reaction kettle and stirred. 23 parts acrylonitrile, 66.7 styrene
Parts, glycidyl methacrylate 0.3 parts, t-dodecyl mercaptan 0.5 parts, azobisisobutyronitrile 0.1 part.
17 copies, Gaffac GB-520 (Toho Chemical Industry Co., Ltd.)
(Made from) and added a mixture of 0.003 parts to make a suspension, and then 75
The temperature was raised to ℃ and held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-1) was 0.49.

Preparation of Copolymer (C-2) 115 parts of distilled water, 1 part of tricalcium phosphate and Demol P
0.001 part was charged into a reaction kettle and stirred. 28 parts of acrylonitrile, 71.7 parts of styrene, 0.3 part of glycidyl methacrylate, 0.6 part of t-dodecyl mercaptan.
Part, 0.17 part of azobisisobutyronitrile and 0.003 part of Gafac GB-520 0.003 part were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-2) is 0.4.
It was 7.

Production of Copolymer (C-3) 115 parts of distilled water, 1 part of tribasic calcium phosphate and Demol P
0.001 part was charged into a reaction kettle and stirred. 28 parts of acrylonitrile, 71.7 parts of styrene, 0.3 parts of glycidyl methacrylate, 0.3 parts of t-dodecyl mercaptan.
Part, 0.17 part of azobisisobutyronitrile and 0.003 part of Gafac GB-520 0.003 part were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-3) is 0.6.
It was 5.

Production of Copolymer (C-4) 115 parts of distilled water, 1 part of tribasic calcium phosphate and Demol P
0.001 part was charged into a reaction kettle and stirred. 23 parts of acrylonitrile, 76.7 parts of styrene, 0.3 part of glycidyl methacrylate, 0.3 part of t-dodecyl mercaptan.
Part, 0.17 part of azobisisobutyronitrile and 0.003 part of Gafac GB-520 0.003 part were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-4) was 0.6.
It was 4.

Preparation of Copolymer (C-5) 115 parts of distilled water, 1 part of tricalcium phosphate and Demol P
0.001 part was charged into a reaction kettle and stirred. 28 parts of acrylonitrile, 72 parts of styrene, 0.3 part of t-dodecyl mercaptan, 0.17 of azobisisobutyronitrile.
And 0.003 parts of Gafac GB-520 were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-5) was 0.65.

Production of Copolymer (C-6) 115 parts of distilled water, 1 part of tribasic calcium phosphate and demol P
0.001 part was charged into a reaction kettle and stirred. 23 parts of acrylonitrile, 77 parts of styrene, 0.5 part of t-dodecyl mercaptan, 0.17 of azobisisobutyronitrile.
And 0.003 parts of Gafac GB-520 were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-6) was 0.49.

Production of Copolymer (C-7) 115 parts of distilled water, 1 part of tricalcium phosphate and Demol P
0.001 part was charged into a reaction kettle and stirred. 23 parts of acrylonitrile, 76.4 parts of styrene, 0.6 part of glycidyl methacrylate, 0.5 part of t-dodecyl mercaptan.
Part, 0.17 part of azobisisobutyronitrile and 0.003 part of Gafac GB-520 0.003 part were added to form a suspension, the temperature was raised to 75 ° C., and the mixture was held for 240 minutes to complete the polymerization. The reduced viscosity of the obtained copolymer (C-7) was 0.4.
It was 9.

Ethylene tetrafluoride resin (D) As the tetrafluoroethylene resin, a full-on fine powder CD manufactured by Asahi IC Eye Fluoropolymers Co., Ltd.
-1, CD-123 and CD-086 were used.

Reinforcing filler (E) ECSO3T-34 (manufactured by Nippon Electric Glass Co., Ltd.) as glass fiber, Pyrofil TR-06N as carbon fiber
(Manufactured by Mitsubishi Rayon Co., Ltd.) was used as talc, Microtalc MP10-52 (manufactured by Pfizer MSP Co., Ltd.).

Examples 1 to 12 and Comparative Examples 1 to 14 The above components (A) to (E) were blended in the proportions shown in Tables 1 and 2 and then mixed in a super mixer (manufactured by Kawata Co., Ltd.). After mixing for 5 minutes, the mixture was pelletized with a twin-screw extruder having a screw diameter of 37 mm. After injection molding using the obtained pellets to obtain a sample, various physical properties were evaluated by the above-mentioned methods. The results are shown in Tables 1 and 2.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

Since the thermoplastic resin composition of the present invention is excellent in impact resistance at low temperature and flow processability at injection molding, it is extremely useful in a wide range of fields such as automobile parts and electronic parts. Therefore, its industrial significance is great.

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Claims (6)

[Claims] 1. A tetrafluoroethylene resin (PT) based on 100 parts by weight of a total amount of the following components (A), (B) and (C).
A high-fluidity thermoplastic resin composition having excellent impact resistance at low temperatures, which comprises 0.05 to 1.0 parts by weight of FE) and 0 to 100 parts by weight of a reinforcing filler (E). (A) Polyester resin mainly composed of polyalkylene terephthalate 15 to 85 parts by weight (B) ABS resin 10 to 50 parts by weight (C) Vinyl cyanide monomer (I) 15 to 40% by weight Aromatic vinyl monomer (II) 59.6-84.9% by weight Polymer obtained by polymerizing 0.1-0.4% by weight of epoxy group-containing vinyl monomer (III) 3-75 parts by weight (D) Tetrafluoride Ethylene resin 0.05 to 1.0 parts by weight (E) Reinforcing filler 0 to 100 parts by weight 2. The thermoplastic resin composition according to claim 1, wherein the vinyl cyanide monomer of the polymer (C) is 15 to 25 parts by weight. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the reduced viscosity η _{SP / C} measured with a 0.2% dimethylformamide solution in the polymer (C) is 0.55 or less. object. 4. The thermoplastic resin composition according to claim 1, wherein the butadiene rubber polymer in the ABS resin (B) is 50 to 80% by weight. 5. The content of the resin component not bonded to the rubbery polymer in the ABS resin (B) is 100 parts by weight of the total amount of the resin compositions ((A), (B) and (C)). ))
The thermoplastic resin composition according to claim 1, wherein the content is 7% by weight or less. 6. The content of the reinforcing filler (E) is 20 to 7.
The thermoplastic resin composition according to claim 1, which is 0 part by weight.