JPH07173363A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition having excellent surface appearance, adhesivity to adhesives and impact resistance and extremely useful for acoustic instrument parts, interior trim for automobile, parts for household appliances, etc., having excellent heat-resistance, low warpage and high rigidity. CONSTITUTION:This resin composition is produced by compounding (a) 15-70wt.% of a graft copolymer obtained by polymerizing 30-70 pts.wt. of a mixture of 15-45wt.% of a vinyl cyanide compound, 55-85wt.% of an aromatic vinyl compound and 0-30wt.% of other copolymerizable vinyl compound in the presence of 30-70 pts.wt. of a conjugated diene rubber, (b) 0-60wt.% of a copolymer composed of 15-45wt.% of a vinyl cyanide compound, 55-85wt.% of an aromatic vinyl compound and 0-30wt.% of other copolymerizable vinyl compound, (c) 20-80wt.% of a polybutylene terephthalate and (d) 1.5-30wt.% of a polyethylene terephthalate and compounding 100 pts.wt. of the obtained resin composition with (e) 5-100 pts.wt. of a filler. The ratio of the components (c)/(d) is 95/5 to 50/50.

Description

Detailed Description of the Invention

[0001]

The present invention relates to surface appearance, adhesiveness,
Because of its excellent impact resistance, heat resistance, low warpage, rigidity, and molding processability, applications requiring these properties, for example, audio equipment parts requiring appearance,
The present invention relates to a thermoplastic resin composition suitable for automobile interior parts, home electric appliance parts and the like.

[0002]

2. Description of the Related Art Rubber-reinforced styrenic resins represented by ABS resins have excellent impact resistance, molding processability, dimensional stability and good surface gloss, and are therefore suitable for automobiles and home appliances. Used as a resin material for various purposes. However, under the condition that it is used at a high ambient temperature, its heat resistance is not sufficient, so that its use is limited.

On the other hand, polybutylene terephthalate (PB
T) has excellent mechanical properties, electrical properties, heat resistance, and chemical resistance, and is used as an engineering plastic in a wide range of fields. However, it has a drawback of poor impact resistance and has a large crystallinity, so that a resin composition particularly reinforced with glass fiber or the like warps in a molded product, resulting in significantly poor dimensional accuracy.

For the purpose of solving such a problem, it has been proposed to blend an ABS resin having excellent impact resistance and dimensional stability with PBT having excellent heat resistance and chemical resistance. However, this composition has a drawback that the surface appearance of the molded product is poor when a filler typified by glass fiber is added for the purpose of imparting heat resistance and rigidity. Further, compared with PBT, the adhesiveness to the adhesive is improved, but it is at a level extremely lower than that of the ABS resin, and further improvement of the adhesive strength has been desired.

JP-A-5-202275 discloses an AB in which the amount of rubber reinforced with glass fibers is 30% by weight or less.
It has been proposed to improve the surface appearance by adding 1 to 10 parts by weight of polyethylene terephthalate (PET) to a composition composed of S resin and PBT resin. However, the adhesiveness with the adhesive is not sufficient and the impact resistance is insufficient, and A added to improve these defects of PBT resin.
The effect of BS did not appear.

As a result of intensive studies aimed at solving these drawbacks, the present inventor has found that a resin composition comprising an ABS resin and a polybutylene terephthalate resin, which is reinforced with a filler and has a rubber amount within a specific range. In, by blending a specific amount of polyethylene terephthalate resin, excellent surface appearance, adhesiveness, impact resistance, further chemical resistance,
We found that it has excellent warpage, rigidity and heat resistance,
The present invention has been completed.

[0007]

That is, according to the present invention, the vinyl cyanide compound 1 is used in the presence of 30 to 70 parts by weight of a conjugated gen rubber.
Graft copolymer obtained by polymerizing 30 to 70 parts by weight of a monomer mixture consisting of 5 to 45% by weight, an aromatic vinyl compound 55 to 85% by weight, and another copolymerizable vinyl compound 0 to 30% by weight. 15 to 70% by weight of the polymer (a),
Copolymer obtained by polymerizing a monomer mixture consisting of 15 to 45% by weight of a vinyl cyanide compound, 55 to 85% by weight of an aromatic vinyl compound, and 0 to 30% by weight of another copolymerizable vinyl compound. Filler (e) with respect to 100 parts by weight of a resin composition consisting of 0 to 60% by weight of the coalesced (b) and 20 to 80% by weight of polybutylene terephthalate (c) and 1.5 to 30% by weight of polyethylene terephthalate (d). It relates to a thermoplastic resin composition comprising 5 to 100 parts by weight and having a mixing ratio of polybutylene terephthalate and polyethylene terephthalate between 95/5 and 50/50.

The present invention will be specifically described below.

The graft copolymer (a) used in the present invention means 55 to 85% by weight of an aromatic vinyl monomer and 15% of a cyanide vinyl monomer in the presence of 30 to 70 parts by weight of a gen rubber. To 45% by weight, and 0 to 30% by weight of another vinyl monomer copolymerizable therewith, 30.
To 70 parts by weight of a graft copolymer (hereinafter referred to as AB
S resin).

The term "gen-based rubber" as used herein means polybutadiene (PBD) and styrene-butadiene rubber (S).
BR) and the like.

Examples of the aromatic vinyl-based monomer in the above ABS resin include styrene (ST), α-methylstyrene (AMS), β-methylstyrene and the like, and these can be used in combination.

Examples of vinyl cyanide monomers include acrylonitrile (AN) and methacrylonitrile, with AN being more preferred.

Examples of the vinyl vinyl monomer copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer include methyl (meth) acrylate and butyl acrylate. In order to obtain the resin composition excellent in surface appearance, adhesion and impact resistance of the present invention, it is essential that the constituent ratio of each component in the ABS resin is within the above range. When the ABS resin (component a) having a rubber amount of less than 30 parts by weight is used, the rubber amount in the entire resin composition is lowered, and the mechanical properties of the final composition, especially the impact resistance are lowered. If the amount of the gen-based rubber in the ABS resin exceeds 70 parts by weight, the moldability of the final composition will deteriorate. Further, when the amount of the aromatic vinyl-based monomer in the monomer mixture forming the matrix resin in the ABS resin exceeds 85% by weight, the physical properties of the ABS resin are deteriorated, while the vinyl cyanide monomer If the amount exceeds 45% by weight, the resin composition becomes non-uniform and the resin tends to be colored.
It is necessary that the content of other vinyl monomers that can be copolymerized with the aromatic vinyl monomer and the vinyl cyanide monomer be 30% by weight or less. If it exceeds 30% by weight, the physical properties of the ABS resin, particularly impact resistance and fluidity, deteriorate.

As a method for producing the ABS resin, a known emulsion polymerization method, bulk suspension polymerization method or solution polymerization method can be mentioned. Especially, the emulsion polymerization ABS resin using a rubber latex has good workability during the subsequent blending. Therefore, it is more preferable.

The copolymer (b) used in the present invention means 55 to 85% by weight of an aromatic vinyl monomer, 15 to 45% by weight of a vinyl cyanide monomer, and other copolymerizable with these. It is a copolymer (hereinafter referred to as AS resin) obtained by copolymerizing a monomer mixture consisting of 0 to 30% by weight of a vinyl-based monomer.

Examples of the aromatic vinyl-based monomer in the AS resin include styrene (ST), α-methylstyrene (AMS), β-methylstyrene and the like, and these can be used in combination.

Examples of vinyl cyanide monomers include acrylonitrile (AN) and methacrylonitrile, with AN being more preferred.

Examples of the vinyl monomer copolymerizable with the aromatic vinyl monomer and the vinyl cyanide monomer include methyl (meth) acrylate and butyl acrylate.

If the amount of the aromatic vinyl monomer in the AS resin is less than 55% by weight, the AS resin becomes brittle, and 85% by weight.
If it exceeds, the thermal stability of the resin deteriorates. On the other hand, when the amount of vinyl cyanide monomer is less than 15% by weight, the AS resin has low chemical resistance, and when it exceeds 45% by weight, moldability is deteriorated. In addition, other vinyl monomers that can be copolymerized with the aromatic vinyl monomer and the vinyl cyanide monomer are 30 at most.
It should be less than 10% by weight, and if it is copolymerized more than that, the fluidity becomes worse.

Further, as a method for producing the AS resin, there are an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method and the like, but there is no problem even if they are produced by any polymerization method.

In the present invention, ABS resin (a) and A
When the mixture of S resin (b) is used, the mixing ratio by weight should be selected in the range of (a) / (b) = 1/0 to 1/4. As long as it is within this mixing ratio range,
There are no particular restrictions on the mixing method.

When the ratio of (a) / (b) is out of the range of 1/0 to 1/4, the physical properties of the final composition, particularly the impact resistance, are lowered, which is suitable for the material resin which is the object of the present invention. Not.

The polybutylene terephthalate resin (PBT) used in the present invention is as follows. That is,
Mention may be made of polymers synthesized from 1,4-butanediol and dimethyl terephthalate. Further, a polymer obtained by co-condensing a small amount of a third component such as ethylene glycol, a diol such as 1,3-propanediol, or a dicarboxylic acid other than terephthalic acid may be used in the synthesis, if necessary.

The polybutylene terephthalate used in the present invention has an intrinsic viscosity of 0.3 to 2.5 dl / g, particularly 0.4 to 2.
Those between 0 dl / g are desirable.

The polyethylene terephthalate resin (PET) used in the present invention includes a polymer obtained by a condensation reaction containing terephthalic acid (or its ester forming derivative) and ethylene glycol (or its ester forming derivative) as main components. it can. Further, a part of the terephthalic acid component or the ethylene glycol component may be replaced with another copolymerization component. Among such copolymerization components, phthalic acids such as isophthalic acid are used as the acid component, dicarboxylic acids such as 2,6-naphthalene dicarboxylic acid, and the like, and the glycol component includes aliphatic diols such as trimethylene glycol and hydroquinone. Examples thereof include dihydroxybenzenes, bisphenols, aromatic phenols, and the like, but the types thereof are not limited. These copolymerization components may be used alone or in combination of two or more. Further, the ratio is preferably 10 mol% or less based on all dicarboxylic acids.

The polyethylene terephthalate used in the present invention is tetrachloroethane / phenol (mixing ratio 1 /
1) The intrinsic viscosity of the solution measured at 30 ° C. is 0.4 to 1.0
The thing of is desirable. Further, those of 0.5 to 0.9 are more preferable.

The compounding amount of PET in 100 parts by weight of the resin composition comprising (a) to (d) is 1.5 to 30.
%, Preferably 3 to 25 parts by weight, more preferably 5 to 25 parts by weight. Here, when the amount of PET is less than 1 part by weight, there is no effect of improving the surface appearance, and when it exceeds 30 parts by weight, the moldability and molding cycle are poor due to the slow crystallization rate of PET. In addition, the heat resistance decreases.

Among the above-mentioned compositions, PBT and PE
The mixing ratio of T is preferably in the range of 95/5 to 50/50, and more preferably 85/15 to 60/40. When the ratio of PET to PBT is less than 5%, the surface appearance modification is not satisfactory. On the contrary, when the ratio exceeds 50%, the transesterification reaction between PBT and PET becomes remarkable, resulting in heat resistance and impact resistance. The family name and the like are reduced, and the various characteristics that the blended body of ABS and PBT should have are significantly reduced.

The filler (e) used in the present invention refers to those generally used as a reinforcing material and a heat resistance improving material, and as such, glass fiber, carbon fiber, aramid fiber, stainless steel or aluminum oxide. Fibrous substances such as metal fibers, ceramics fibers, titanate whiskers, boron whiskers, zinc oxide whiskers, asbestos, glass flakes, glass beads, mica, silica, talc, clay, calcium carbonate, wollastonite, barium sulfate, Powder such as titanium oxide, or
Examples include plate-shaped inorganic fillers. Among them, chopped strand type glass fiber is preferable. The glass fiber is not particularly limited as long as it is usually used for reinforcing a resin. Further, the surface of the glass fiber may be subjected to a sizing agent, a coupling agent, or other surface treatment.
The length of the glass fiber may be at least the length at which the reinforcing effect appears. From the viewpoint of the reinforcing effect, a longer length is preferable, but in view of appearance, workability during mixing, pelletizing, etc., it is preferably about 0.4 to 6.0 mm, and the length of the glass fiber in the final molded product is 0. It is preferable that it is 0.2-2 mm. Also, these fillers can be used alone, or
It is possible to use more than one kind.

The blending amount of the filler (e) is 5 to 100 parts by weight based on 100 parts by weight of the resin composition consisting of a to d,
It is preferably 10 to 80 parts by weight. If the blending amount is less than 10 parts by weight, heat resistance, strength, elastic modulus, etc. are insufficient, and if it exceeds 100 parts by weight, the surface appearance is deteriorated and the fluidity is lowered, so that a good molded product cannot be obtained.

For blending the above components, an extruder and a
It is sufficient to melt and knead using a dull, roll or the like. A preferred method is a method in which powdered raw materials are mixed using a Henschel mixer or the like, and this is heated and melted using an extruder to be extruded and pelletized.

In the final composition of the present invention, various additives which are usually used, such as plasticizers, antioxidants, stabilizers, pigments and dyes, can be used. Further, a flame retardant may be added to the final composition of the present invention. As the flame retardant, a phosphorus compound such as triphenyl phosphate or a halogen compound such as decabromodiphenyl oxide is used. In addition, it is necessary to suppress the addition amount of these additives to 40 parts by weight or less per 100% by weight of the resin composition. If it is added more than this, the physical properties of the final composition deteriorate.

[0033]

EXAMPLES Examples of the present invention will be described below in detail. However, the present invention is not limited to these examples. All parts and% in the examples are based on weight. The types of (a) ABS resin and (b) AS resin used in the present invention are shown in Tables 1 and 2.

[0034]

[Table 1]

[Table 2] The properties of the compositions obtained in Examples 1 to 8 and Comparative Examples 1 to 8 were evaluated by the following 6 items.

(1) 60 ° reflectance The surface appearance was evaluated by 60 ° reflectance according to JIS K7105. Using a black colored pellet, a flat molded article having a length of 100 mm, a width of 50 mm and a thickness of 3 mm was molded by an injection molding machine, and the 60 ° reflectance at a fixed position was measured.

(2) Adhesive strength The tensile shear adhesive strength was measured according to JIS K6850. 12 cm in length, 2.5 cm in width and 3 in thickness by injection molding machine
mm into a molded product, and the test pieces are 2.5 × 1.
Bonded with a bonding area of 25 cm, 7 at 23 ° C and 65 RH
After curing for 2 days, the tensile tester was operated at 2 mm / min. The strength was measured at a pulling speed of.

(3) Izod impact strength Measured according to ASTM D256.

(4) Heat distortion temperature It was measured according to ASTM D648.

(5) Tensile Strength It was measured according to ASTM D638.

(6) Flexural Modulus Measured according to ASTM D790.

(Examples 1 to 3 and Comparative Examples 1 to 3) ABS resin (a-1), AS resin (b) and PBT resin (intrinsic viscosity 0.75) having the composition ratios shown in Table 3 ( c),
Total 10 parts of PET resin (d) having an intrinsic viscosity of 0.73
The glass fiber (e) having a fiber length of 3 mm and a fiber diameter of 13 μm was added to 0 part by weight, and 0.1 part of each of the antioxidant and the lubricant was further added, and then uniformly dry blended using a V-type blender. The resin mixture after blending was kneaded and extruded at 260 ° C. using a 40 mm single screw extruder manufactured by Osaka Seiki Co., Ltd.

No bent-up or surging was observed during extrusion. The extruded strand was cooled in a water bath and pelletized. 9 pellets in hot air dryer
After being dried at 0 ° C. for 4 hours, injection molding was performed. The injection molding was carried out by molding a test piece for physical property evaluation with a TS-100 type injection molding machine manufactured by Nissei Plastic Industry Co., Ltd. Molding conditions are as follows: cylinder temperature is 260 ℃, mold temperature is 80 ℃, molding cycle is
Injection was 15 seconds and cooling was 30 seconds.

The test pieces were a 1/4 "bar for bending test, heat distortion temperature test and Izod impact test, and a flat plate for surface appearance observation and a bar for measuring adhesive strength.

Table 3 shows the results of evaluation of the physical properties and surface appearance of the test pieces thus obtained. Comparative Example 1
3 to 3, PET, PBT, AB which are essential components of the present invention
The test result of the composition containing neither S was examined. When PET is not blended, the surface gloss and adhesive strength are poor, when PBT is not blended, the surface gloss and heat resistance are poor, and when ABS is not blended, the adhesive strength and impact resistance are poor. On the other hand, in Examples 1 to 3, PBT, ABS and A
The effect of adding PET to the S blend was investigated. By incorporating these essential components, it was possible to obtain a composition having a good surface appearance, in which no rise of glass fibers was observed on the surface of the molded article, high adhesive strength, and high impact resistance and heat resistance.

[0045]

[Table 3] (Examples 4 to 8 and Comparative Examples 4 to 8) In these examples, the respective components were mixed in the proportions shown in Table 4 in the same manner as in Example 1. The results are shown in Table 4. In Comparative Example 4, ABS (a-2) outside the scope of claims was used. In Comparative Examples 5 and 6, the compounding ratio of PBT was compared, and in Comparative Examples 7 and 8, PBT / PE was used.
When a composition having a T compounding ratio out of the claimed range was examined, any of the surface appearance, impact resistance, adhesiveness, and heat resistance was insufficient. On the other hand, Examples 4 to 8
Then, although the mixing ratio of each component was changed within the scope of claims,
All had high surface appearance, adhesive strength, impact resistance, and heat resistance.

[0046]

[Table 4]

[0047]

EFFECTS OF THE INVENTION A molded article comprising the composition of the present invention is excellent in surface appearance, adhesiveness with an adhesive and impact resistance, and is further excellent in low warpage, rigidity, heat resistance and molding processability. Therefore, it is extremely useful for applications in which these properties are required, such as audio equipment parts, interior parts for automobiles, and home appliances parts that require appearance.

Claims (2)

[Claims] 1. A cyanide vinyl compound in an amount of 15 to 45% by weight, an aromatic vinyl compound in an amount of 55 to 85% by weight, and another copolymerizable vinyl compound in the presence of 30 to 70 parts by weight of a conjugated gen rubber. ~ 30 wt% monomer mixture 3
15 to 70% by weight of a graft copolymer (a) obtained by polymerizing 0 to 70 parts by weight, and a vinyl cyanide compound 15
~ 45 wt%, aromatic vinyl compound 55-85 wt%,
And 0 to 60% by weight of a copolymer (b) obtained by polymerizing a monomer mixture consisting of 0 to 30% by weight of another copolymerizable vinyl compound and 20 to 80% by weight of polybutylene terephthalate (c). % And polyethylene terephthalate (d) 1.5 to 30% by weight, 100 parts by weight of the resin composition, and 5 to 100 parts by weight of the filler (e) are mixed. 2. The thermoplastic resin composition according to claim 1, wherein the mixing ratio of polybutylene terephthalate and polyethylene terephthalate is between 95/5 and 50/50.