JPH04372643A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To prepare a compsn. excellent in resistance to environmental stress crack and coatability by compounding a mixture of a vinyl polymer with an acrylate polymer, a rubber-contg. styrene resin, and a thermoplastic polyester resin. CONSTITUTION:This compsn. is prepd. by compounding 0.5-50wt.% polymer mixture obtd. by coagulating a mixed emulsion consisting of 20-90wt.% (solid base) emulsion of a vinyl polymer having a glass transition point higher than 20 deg.C, a gel content of 10% or lower, a solubility parameter of 9.0-11.0 (cal/cc)<1/2>, and a wt.-average mol.wt. in terms of PS of (2-40)X10<5> and 10-80 wt. % (solid base) emulsion of an acrylate polymer or copolymer having a glass transition point lower than 20 deg.C, a gel content of 70% or lower, and a solubility parameter of 8.4-9.8 (cal/cc)<1/2>, 30-98.4wt.% rubber-contg. styrene resin, and 0.1-20 wt.% thermoplastic polyester resin.

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 having excellent environmental stress cracking resistance and paintability.

0002

2. Description of the Related Art Conventionally, rubber-containing styrenic resins, typified by ABS resins, have been used in a wide range of applications because of their excellent mechanical properties and moldability. In addition, because it has excellent paintability, it has recently been increasingly used after being painted for the purpose of decoration and prevention of UV deterioration. However, when rubber-containing styrenic resin comes into contact with chemicals under stress, it is observed that cracks occur and, in severe cases, breakage. Stress cracks that occur after painting are also caused by distortion remaining inside the molded product. This is one of the environmental stress cracking phenomena caused by release due to contact. On the other hand, the present inventors have already mixed an acrylic acid ester polymer and a vinyl monomer polymer in an emulsion state, and then separated the obtained polymer composition and mixed it into a rubber-containing styrene resin. They have found and reported that the environmental stress cracking resistance is dramatically improved by this method. (Unexamined Japanese Patent Publication No. 62-1587
Furthermore, it has been confirmed that the resin composition of the invention has good affinity with solvents in paints and thinners, and has excellent environmental stress cracking resistance, so it maintains good paint adhesion. There is. However, because this resin composition has a strong affinity with solvents, it absorbs a large amount of solvent near the gate or weld of the injection molded product, causing an abnormality commonly referred to as suction or paint crazing to occur on the surface of the paint film. may be observed in This abnormal phenomenon in the paint surface condition is caused by the rubber component dispersed in the rubber-containing styrene resin or the acrylic acid ester polymer particles being flattened and deformed by the shear stress during injection molding, and they have a high affinity. Since the deformation is recovered by absorbing the solvent in the paint or thinner, it is thought that this is caused by the formation of streak-like irregularities on the surface of the paint film. Therefore, the above-mentioned phenomenon is particularly noticeable near gates or welds where particles are easily flattened or deformed.

0003

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition which has excellent resistance to environmental stress cracking and which has improved surface defects after painting as described above.

0004

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, we have developed a polymer obtained by mixing an acrylic ester polymer and a vinyl monomer polymer in an emulsion state and then separating them. By adding thermoplastic polyester when mixing the composite composition with rubber-containing styrenic resin, it has excellent environmental stress cracking resistance, and the surface abnormal phenomenon called paint sucking phenomenon has been significantly improved. This discovery led to the present invention.

[0005] To summarize the present invention, the present invention relates to a thermoplastic resin composition, which includes: 1. (A)
It is a polymer of vinyl monomers (hereinafter referred to as component (A) polymer), and its glass transition temperature exceeds 20 degrees Celsius,
The gel content is 10% or less, the solubility parameter is 9.0 to 11.0 (cal/cc) 1/2, and the weight average molecular weight based on polystyrene is 2 x 105 or more and 40 x 105 Emulsions of polymers less than 20 to 9
(B) a homopolymer of acrylic ester monomer or a copolymer of acrylic ester monomer and other copolymerizable monomer; The glass transition temperature is 20 degrees Celsius or less, the gel content is 70% or less, and the solubility parameter is 8.4~
9.8(cal/cc)1/2 polymer (hereinafter ((
A polymer mixture C0.5-50 of (A) and (B) obtained by separating from an emulsion of 10-80% by weight (as solid content of the polymer) of component polymer B) Weight %, 2. 3. rubber-containing styrenic resin 30-98.4% by weight; The thermoplastic resin composition is composed of 0.1 to 20% by weight of a thermoplastic polyester resin and has excellent environmental stress cracking resistance and excellent paintability.

Vinyl monomers constituting the component (A) polymer of the present invention include, for example, styrene, α-methylstyrene,
Aromatic vinyl monomers such as vinyltoluene, t-butylstyrene, cyanostyrene, and chlorostyrene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; methyl acrylate, ethyl acrylate, butyl acrylate, and hexyl acrylate. ester, cyclohexyl acrylate, octyl acrylate, decyl acrylate, octadecyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, glycidyl acrylate, phenyl acrylate Acrylic acid ester monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, decyl methacrylate octadecyl methacrylate, hydroxyethyl methacrylate, methoxyethyl methacrylate, glycidyl methacrylate,
Methacrylic acid ester monomers such as phenyl methacrylate, amide monomers such as acrylamide and methacrylamide, unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, and itaconic acid, vinyl chloride, vinylidene chloride, etc. halogenated vinyl monomers, fatty acid vinyl ester monomers such as vinyl formate, vinyl acetate, vinyl propionate, vinyl decanoate, and vinyl octadecanoate, olefins such as ethylene, propylene, 1-butene, isobutylene, and 2-butene. Monomers, maleimide monomers such as maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-toluylmaleimide, acid anhydrides such as maleic anhydride Conjugated diene monomers such as butadiene, isoprene, chloroprene, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, hexyl vinyl ether, decyl vinyl ether, octadecyl vinyl ether, phenyl vinyl ether, cresyl vinyl ether,
Examples include, but are not limited to, vinyl ether monomers such as glycidyl vinyl ether, vinyl ketone monomers such as methyl vinyl ketone and phenyl vinyl ketone, and vinyl pyridine.

The vinyl monomer constituting the component (A) polymer of the present invention may be a polyfunctional vinyl monomer,
The polyfunctional vinyl monomer is, for example, divinylbenzene,
Ethylene glycol di(meth)acrylate, 1,3-
Butylene glycol di(meth)acrylate, 1,4-
Butylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane tri(meth)acrylate, allyl(meth)acrylate
Acrylate, vinyl (meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, pentaethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, tetradecaethylene glycol
di(meth)acrylate, eicosaethylene glyco
di(meth)acrylate, dipropylene glycol di(meth)acrylate, pentapropylene glycol di(meth)acrylate, nonapropylene glycol di(meth)acrylate,
meth)acrylate, tetradecapropylene glycol di(meth)acrylate, eicosapropylene glyco
Examples include di(meth)acrylate, 1,6-hexyl di(meth)acrylate, and the like. Here, for example, ethylene glycol di(meth)acrylate means ethylene glycol diacrylate or ethylene glycol dimethacrylate.

The polymer component (A) of the present invention must have a glass transition temperature of over 20 degrees Celsius. A more preferable glass transition temperature is 30 degrees Celsius or higher. (A) The glass transition temperature of the component polymer is 20 degrees Celsius or less (A
Polymer mixture C obtained by mixing the component polymer () and the component polymer (B) is industrially disadvantageous because it is difficult to handle as powder or pellets, and it is difficult to handle as a powder or pellet, and it is difficult to handle as a powder or pellet. It is not preferable because it greatly reduces heat resistance when mixed with

The component (A) polymer of the present invention has a molecular weight of 9.0 to 1
It is necessary to have a solubility parameter in the range of 1.0 (cal/cc) 1/2, and a more preferable range is 9.5 to 10.5 (cal/cc) 1/2. be. Solubility parameter deviates from the scope of the present invention (A)
A thermoplastic resin composition obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin with a polymer mixture C in which a component polymer is mixed with a component polymer (B) exhibits a delamination phenomenon in a molded product. , surface defects such as flow marks appear, which is undesirable.

[0010] In this specification, the solubility parameter refers to the solubility parameter published by John Wiley & Sons, New York, 1975, published by J.
Drup) and Inmargut (E.H.
Immergut), Polymer Handbook (
Polymer Handbook) 2nd edition IV33
Using the solubility parameter values described on pages 7 to IV, page 359, the solubility parameter δT of the copolymer is determined by calculating the solubility parameter δT of the individual vinyl monomers constituting the copolymer consisting of m types of vinyl monomers. It is calculated by the following formula [I] from the solubility parameter δn of the homopolymer and its weight fraction Wn.

[0011]

For example, the solubility parameters of butyl polyacrylate and polyethyl acrylate are each 8.8.
(cal /cc) 1/2 and 9.4 (cal /c
c) 1/2, butyl polyacrylate 70% by weight
The solubility parameter of the copolymer consisting of 30% by weight of polyethyl acrylate is 9.0 (cal/cc)1/
It can be calculated as 2.

The component (A) polymer of the present invention has a weight average molecular weight of 2×10 5 or more and 40×10
It must be less than 5. The weight average molecular weight is
Heat obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin with a polymer mixture C in which a component polymer (A) having a molecular weight of less than 2 x 105 based on polystyrene is mixed with a component polymer (B). Plastic resin compositions are undesirable because surface defects such as delamination and flow marks appear on molded products. Also, the weight average molecular weight is 40×10
If it is more than 5, the fluidity of the resin will decrease, which is not preferable in terms of actual molding.

In this specification, the weight average molecular weight based on polystyrene is the weight average molecular weight determined by gel permeation chromatography assuming that the component polymer (A) is polystyrene. That is, using polystyrene, which has a narrow molecular weight distribution and a known molecular weight, as a standard substance, a calibration curve is created by determining the relationship between the outflow peak volume of the gel permeation chromatogram and the molecular weight. Next, a gel permeation chromatogram of the component polymer (A) is measured, and the molecular weight is determined from the outflow volume using the above-mentioned calibration curve, and the weight average molecular weight is calculated according to a conventional method.

The polymer component (A) of the present invention must have a gel content of 10% or less. The gel content as used in the present invention means that approximately 1.0 g of component polymer (A) is weighed accurately (S0 g), placed in a cage made of 400 mesh stainless steel wire mesh, and placed in 100 g of methyl ethyl ketone. After soaking in water and leaving it for 24 hours at 5 degrees Celsius, the basket was pulled up and air-dried at room temperature.The weight S1 g of component (A) polymer insoluble matter was measured, and the value was calculated according to the following formula [II]. means.

(S1/S0)×100(%)...
[II]

[0017] Gel content exceeds 10% (A
A thermoplastic resin composition obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin with a polymer mixture C obtained by mixing the component polymer (B) with the component polymer (B) has a high gloss of a molded product. Less desirable.

As for the method for producing the component polymer (A) of the present invention, any known techniques such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization can be applied, and production by emulsion polymerization is industrially most advantageous. It is. One reason is that in the present invention, component polymers (A) and (B) are mixed in an emulsion state, and one reason is that according to emulsion polymerization, a high molecular weight polymer This is because it can be easily manufactured industrially.

In producing the component (A) polymer of the present invention, the vinyl monomer is selected depending on the glass transition temperature, gel content, solubility parameter, and It is arbitrary as long as the weight average molecular weight satisfies the provisions of the present invention.

A chain transfer agent may be used to control the molecular weight of the component polymer (A). In particular, when copolymerizing polyfunctional vinyl monomers, it is possible to produce component (A) polymers that have a branched structure and a low gel content by using a chain transfer agent in combination. can.

Chain transfer agents that can be used in the present invention include, for example, octylmercaptan, decylmercaptan, dodecylmercaptan, thioglycolic acid, ethyl thioglycolate, butyl thioglycolate, ethyl o-mercaptobenzoate, and 1-naphthyl. Examples include sulfur compounds such as disulfide and sulfur, halogen compounds such as carbon tetrabromide, hydrocarbons such as limonene and terpinolene, nitro compounds such as trinitrophenol and trinitrobenzene, and benzoquinone.

Next, the component (B) polymer of the present invention is a homopolymer of an acrylic ester monomer or a copolymer of an acrylic ester monomer and another copolymerizable monomer. Specific examples of acrylic ester monomers are (
A) An example of the vinyl monomer constituting the component polymer is the same as the specific example of the acrylic acid ester monomer listed above. Further, specific examples of the copolymerizable monomers constituting the component polymer (B) include acrylic monomers among the monomers described as examples of the vinyl monomers constituting the component polymer (A). This is the same as the specific example except for the acid ester monomer.

[0023] In addition, a polyfunctional vinyl monomer or a chain transfer agent can be used in the polymerization of component (B) of the present invention, and specific examples of the polyfunctional vinyl monomer and chain transfer agent are as follows. , are the same as the specific examples described for the component (A) polymer.

The component (B) polymer of the present invention must have a glass transition temperature of 20 degrees Celsius or less. A more preferable glass transition temperature is 10 degrees Celsius or less. (B)
The glass transition temperature of the component polymer exceeds 20 degrees Celsius (B
A thermoplastic resin composition obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin with a polymer mixture C obtained by mixing component polymer (A) with component polymer (A) has excellent environmental stress cracking resistance. is poor and undesirable.

The component (B) polymer of the present invention must have a gel content of 70% or less. The method for measuring the gel content is the same as the measurement procedure for the component polymer (A), except that 100 g of toluene is used instead of 100 g of methyl ethyl ketone as the solvent, and is calculated according to the above-mentioned formula [II]. Polymer mixture C in which a (B) component polymer having a gel content of more than 70% is mixed with a (A) component polymer
A thermoplastic resin composition obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin using the above method is undesirable because it has poor environmental stress cracking resistance.

The component (B) polymer of the present invention has a molecular weight of 8.4 to 9.
．． It is necessary to have a solubility parameter in the range of 8 (cal/cc) 1/2. A more preferable numerical range is 8.6 to 9.6 (cal/cc) 1/2. The method for determining the solubility parameter is the same as that for measuring the component polymer (A), and is calculated according to the above-mentioned formula [I].

The solubility parameter of the component polymer (B) is less than 8.4 (cal/cc) 1/2 or 9.8 (
cal/cc) 1/2, a polymer composition C prepared by mixing the (B) component polymer with the (A) component polymer is used to mix the rubber-containing styrenic resin and thermoplastic polyester resin. The thermoplastic resin composition obtained by this method has poor environmental stress cracking resistance and is therefore undesirable.

Regarding the method for producing the component polymer (B),
Any known technique such as emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization can be applied, and production by emulsion polymerization is industrially most advantageous, similar to the method for producing the component (A) component polymer.

When producing the component (B) polymer, the selection of the acrylic ester monomer or the copolymerizable monomer depends on the glass transition temperature of the obtained component (B) polymer,
The gel content and solubility parameters are arbitrary as long as they satisfy the provisions of the present invention.

In the present invention, component (A) polymer 20 to 90
% by weight and 10 to 80% by weight of the (B) component polymer are mixed to form a polymer mixture C, but the polymer mixture C in which the content of the (B) component polymer is less than 10% by weight is rubber-containing. A thermoplastic resin composition obtained by mixing a styrene resin and a thermoplastic polyester resin has poor environmental stress cracking resistance, and when the content exceeds 80% by weight, molded products made of the thermoplastic resin composition may suffer from delamination phenomenon. Surface defects such as flow marks appear, which is undesirable.

In the present invention, an emulsion of the polymer component (A) and an emulsion solution of the polymer component (B) are mixed in an emulsion state. When the component polymer (A) or the component polymer (B) is produced by emulsion polymerization, the emulsion polymerization solution obtained by emulsion polymerization can be used as it is, but if it is produced by another polymerization method, In some cases, a step of emulsifying the obtained polymer is necessary.

For emulsification of polymers obtained by other polymerization methods, any known technique can be applied. For example, (A
) A method in which a polymer solution is mixed and stirred with an emulsifier and water to form an emulsion, and then the solvent is removed; (B) A fine powder obtained by crushing the polymer is mixed and stirred with an emulsifier and water to form an emulsion. (C) A method in which a polymer is ground into an emulsion in the presence of an emulsifier and water, but is not limited to this method.

The particle size of the polymer in the emulsion of the component polymer (A) or the component polymer (B) is not particularly limited;
It is preferable that the area average particle diameter is 5 μm or less. Here, the area average particle diameter is calculated according to the following formula [III] by taking an electron micrograph of the emulsion and setting fi to the fraction of the particle diameter where the particle diameter is di.

Σfi di 3 /Σfi di 2 ...
[III]

In particular, the (B) component polymer having an area average particle diameter of more than 5 μm is used as the (A) component polymer.
A thermoplastic resin composition obtained by mixing a rubber-containing styrenic resin and a thermoplastic polyester resin using polymer mixture C mixed with a component polymer does not cause delamination phenomenon or flow marks on molded products. This may occur.

The type of emulsifier used for emulsion polymerization of component polymer (A) or component polymer (B) or emulsification of the polymer is not particularly limited, and includes anionic surfactants, cationic surfactants, and amphoteric surfactants. Any active agent and nonionic surfactant can be selected, but anionic surfactants can be used most advantageously.

The (A) component polymer emulsion and the (B) component polymer emulsion can be mixed by using devices such as a fixed container type mixing device, a rotating container type mixing device, a pipeline mixer, and a static mixer. can be used to perform mixing.

A method for separating polymer mixture C from a mixed emulsion of component (A) polymer emulsion and component (B) polymer emulsion is, for example, by adding hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, etc. to the emulsion. Acid, electrolyte such as sodium chloride, calcium chloride, aluminum chloride, sodium sulfate, magnesium sulfate, polyvinyl alcohol, polyethylene glycol, polyethylene glycol, polypropylene glycol block copolymer, carboxymethyl cellulose, etc. There are methods of adding a precipitating agent such as an aqueous polymer, a method of freezing the emulsion to break the emulsion, and a method of spraying the emulsion into a high-temperature gas.

The polymer mixture C separated from the mixture of the component (A) polymer emulsion and the component (B) polymer emulsion is:
Furthermore, it can be supplied to a melt-kneading device for melt-kneading. Examples of melt-kneading devices that can be used include Banbury mixers, intensive mixers, mixtruders, co-kneaders, extruders, and rolls. It is also possible to use a melt kneading device with a dehydration mechanism disclosed in Japanese Patent Publication No. 59-37021, but when using this device, the emulsion and precipitating agent are continuously supplied to the device. It is also possible to perform kneading, demulsification, dehydration, drying and melt-kneading continuously in the same device.

Monomers constituting the rubber component of the rubber-containing styrenic resin in the present invention include conjugated diene monomers such as butadiene, isoprene, dimethylbutadiene, chloroprene, and cyclopentadiene, 2,5-norbornadiene, 1, Homopolymerization of non-conjugated diene monomers such as 4-cyclohexadiene and 4-ethylidene norbornene,
or conjugated diene or non-conjugated diene and styrene, α-
Aromatic vinyl monomers such as methylstyrene and vinyltoluene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, and octyl. (meth)acrylic acid ester monomers such as acrylate, ethylene, propylene, 1-butene,
A copolymer with an olefin monomer such as isobutylene or 2-butene can be used.

Further, for the rubber component, a copolymer obtained by copolymerizing a polyfunctional vinyl monomer as a crosslinking monomer can also be used, and the polyfunctional vinyl monomer includes vinylbenzene,
Ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane trimethacrylate Examples include allyl acrylate, allyl methacrylate, vinyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0042] The rubber component used in the rubber-containing styrenic resin of the present invention must have a graft active site, and specifically, the rubber component must have a carbon-carbon double bond in the rubber molecule. It is preferable. The method for polymerizing the monomers is as follows:
For example, known techniques such as emulsion polymerization and solution polymerization can be used. Furthermore, the rubber component of the rubber-containing styrenic resin does not need to be of one type, and may be a mixture of two or more separately polymerized rubber components.

Monomers constituting the resin component of the rubber-containing styrenic resin in the present invention include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, and t-butylstyrene, acrylonitrile, and methacrylonitrile. Nitrile monomers such as methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate and other (meth)acrylic acid ester monomers, maleimide, N-methylmaleimide , N-ethylmaleimide, N-propylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-tolylmaleimide, N-xylylmaleimide, and other maleimide monomers, which can be used alone or in copolymerization. However, it is essential to contain a styrene monomer and a nitrile monomer.

The rubber-containing styrenic resin used in the present invention is composed of a rubber component and a resin component as described above, and a graft structure is present at the interface between the rubber component having a spherical structure and the resin component which is a continuous phase. It is necessary to do so. It is known that such a structure can be achieved by a so-called graft polymerization method in which part or all of the monomers constituting the resin component are polymerized in the presence of a rubber component. The resin can also be produced by known graft polymerization techniques.

For example, it is possible to mix a separately polymerized resin component with the rubber-containing styrenic resin for the purpose of adjusting the content of the rubber component contained in the rubber-containing styrenic resin. The resin component does not need to have the same composition as the resin component obtained by graft polymerization. For example, a resin component obtained by copolymerizing acrylonitrile, styrene, and α-methylstyrene may be mixed with a rubber-containing styrenic resin obtained by graft polymerizing acrylonitrile, styrene, and methyl methacrylate in the presence of polybutadiene. can.

Specific examples of the rubber-containing styrenic resin of the present invention include ABS (acrylonitrile-butadiene-styrene) resin, heat-resistant ABS (acrylonitrile-butadiene-styrene-α-methylstyrene) resin, and AAS.
(acrylonitrile-acrylic acid ester-styrene)
resin, AES (acrylonitrile-EPDM-styrene) resin, MBAS (methyl methacrylate-butadiene-acrylonitrile-styrene) resin, etc.

The content of the rubber component contained in the rubber-containing styrenic resin of the present invention is 2 to 70% by weight, preferably 5% by weight.
~60% by weight. If the content of the rubber component is less than 2% by weight, the impact resistance of the thermoplastic resin composition obtained by mixing the polymer mixture C and the thermoplastic polyester resin will be low, and if it exceeds 70% by weight, the rigidity or heat resistance will be poor. decreases.

Furthermore, the resin components of the rubber-containing styrenic resin of the present invention include 40 to 90% by weight of styrene monomer, 5 to 50% by weight of nitrile monomer, and 0% of other copolymerizable monomers.
It is preferable that the content is 40% by weight. If the styrene monomer content is less than 40% by weight, the fluidity will be low, and if it exceeds 90% by weight, the impact resistance or rigidity will decrease. Furthermore, if the nitrile monomer content is less than 5% by weight, the impact resistance and rigidity will be low;
If it exceeds % by weight, fluidity will decrease.

The thermoplastic polyester resin used in the present invention is composed of a high molecular weight polymeric glycol or glycol isophthalate having a repeating unit of the following formula shown in [Chemical formula 1], and a mixture of these esters. It is.

Particularly preferred thermoplastic polyester resins include polyethylene terephthalate and poly-1,4
-Butylene terephthalate can be used.

[0051]

[Chemical formula 1]

In the present invention, the polymer mixture C0.5-50
Weight%, rubber-containing styrenic resin 30-98.4% by weight
and 0.1 to 20% by weight of a thermoplastic polyester resin to produce a thermoplastic resin composition. More preferably, 2 to 40% by weight of polymer mixture C, 55 to 97% by weight of rubber-containing styrenic resin, and 1 to 10% by weight of thermoplastic polyester.
Mix % by weight.

If the amount of polymer mixture C added is less than 0.5% by weight, the resulting thermoplastic resin composition will have poor environmental stress cracking resistance, and if it exceeds 50% by weight, the rigidity, heat resistance or moldability will be poor. If the rubber-containing styrenic resin is less than 30% by weight, the impact resistance will be poor, which is preferable, and if it exceeds 98.4% by weight, the environmental stress cracking resistance will be poor, which is not preferable. Furthermore, if the thermoplastic polyester resin is less than 0.1% by weight, the coating crazing properties will be poor, and if it exceeds 20% by weight, the coating adhesion will be poor, which is not preferable.

In the present invention, a thermoplastic resin composition is prepared by mixing the polymer mixture C, a rubber-containing styrene resin, and a thermoplastic polyester resin. By mixing, a desired thermoplastic resin composition can be manufactured. Examples of the mixing device include a Henschel mixer, a V-type blender, and a tumbler.

Another mixing method is a melt-kneading method, and specific examples of melt-kneading equipment include a Banbury mixer, a co-kneader, an extruder, and a roll. Examples of the embodiment of the melt-kneading include a method of simultaneously supplying the polymer mixture C, a rubber-containing styrenic resin, and a thermoplastic polyester resin to a melt-kneading device, or a method of melt-kneading the polymer mixture C and a rubber-containing styrenic resin. There is a method of obtaining a thermoplastic resin composition by melt-kneading a thermoplastic polyester resin with a solid solid.

The thermoplastic resin composition of the present invention is widely used in, for example, automobile parts, home appliances, household goods, etc.
Specific examples include cowlings, lamp covers, undercovers, mirror covers, etc., which are exterior parts of motorcycles and four-wheeled vehicles.

[0057]

EXAMPLES The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to these Examples. Note that all parts and percentages described in Examples and Comparative Examples are based on weight.

Examples 1 to 10 and Comparative Examples 1 to 10 [(A
) Production of component polymers --- Production of A-1 to A-5] Pure water 1
50 parts of potassium stearate and 2 parts of potassium stearate were placed in an autoclave and heated to 50 degrees Celsius while stirring. Here,
Ferrous sulfate heptahydrate 0.005 part, ethylenediamine 4
0.01 part of tetrasodium acetate dihydrate, and 0.01 part of sodium formaldehyde sulfoxylate dihydrate.
An aqueous solution prepared by dissolving 3 parts in 10 parts of pure water was injected. Next, 100 parts of a monomer mixture having the composition shown in Table 1 was continuously added over 4 hours. At the same time, an aqueous solution of 0.05 parts of potassium persulfate dissolved in 25 parts of pure water was continuously added over 6 hours. After the addition of the monomer mixture was completed, 0.1 part of diisopropylbenzene hydroperoxide was added, and the system was heated to 70 degrees Celsius and stirred for an additional 2 hours to complete the polymerization.

[0059]

[Table 1]

[Production of (B) component polymer---Production of B-1 to B-6]
Charge 120 parts of pure water and 2 parts of sodium dodecylbenzenesulfonate into an autoclave, and heat to 6 degrees Celsius while stirring.
It was heated to 5 degrees. Here, ferrous sulfate heptahydrate 0.00
5 parts, ethylenediaminetetraacetic acid tetrasodium dihydrate 0
．． An aqueous solution prepared by dissolving 0.01 part of sodium formaldehyde sulfoxylate dihydrate and 0.3 part of sodium formaldehyde sulfoxylate dihydrate in 10 parts of pure water was injected. Next, monomer mixture 10 having the composition shown in Table 2
20% of 0 parts was poured into an autoclave, and 2.5 parts of a 0.2% aqueous solution of potassium persulfate was added to initiate polymerization. Simultaneously with the start of polymerization, the remaining amount of the monomer mixture was continuously added over 4 hours. Further, at the same time as the start of polymerization, an aqueous solution of 0.05 part of potassium persulfate dissolved in 20 parts of pure water was continuously added over 6 hours. After the addition to the aqueous potassium persulfate solution was completed, the contents of the autoclave were cooled to complete the polymerization.

[0061]

[Table 2]

[Production of Polymer Mixture C] 50 parts of component (A) polymer emulsion (as solid content of the polymer) and 50 parts of component (B) polymer emulsion (as solid content of polymer) were prepared. Mix in an emulsion state, and then add polyethylene glycol-polypropylene glycol block copolymer (ethylene oxide polymerization fraction in total molecule 80%, polypropylene glycol molecular weight 1750, manufactured by Asahi Denka Kogyo Co., Ltd., Pluronic F). -68) 0.7 part of 10% aqueous solution was added. An aqueous solution prepared by dissolving 5 parts of calcium chloride dihydrate in 400 parts of pure water was heated to 80 to 95 degrees Celsius, and the mixed emulsion was poured into the solution with stirring to precipitate a polymer mixture. The obtained slurry was filtered, washed with water, and dried in an atmosphere of 70 degrees Celsius to obtain a polymer mixture C.

[0063] Each physical property value was determined by the following method. (1) Glass transition temperature The solid obtained by dropping the (A) component polymer or (B) component polymer emulsion into methanol was dried and measured using a 910 differential scanning calorimeter, which is a DuPont measuring device, and a 990 differential scanning calorimeter. Measured using a thermal analyzer.

(2) Gel content The emulsion of the polymer component (A) or the polymer component (B) was dropped into methanol, and the obtained solid was dried. About 1.
0 g was accurately weighed, measured by the method described above, and calculated by formula [II]. However, the solvents used were different for the (A) component polymer and the (B) component polymer; methyl ethyl ketone was used for the (A) component polymer, and toluene was used for the (B) component polymer.

(3) Solubility parameter - The solubility parameter value [unit: (cal/cc) 1/2] of each polymer used to calculate the solubility parameter in each example is as follows. It is. Polybutyl acrylate; 8.8 Polyethyl acrylate; 9.4 Polymethyl methacrylate; 9.5 Polyacrylonitrile; 12.5 Polystyrene; 9.1 Polyvinyltoluene; 8.9 Poly(
t-butylstyrene); 7.9

[0066](
4) Weight average molecular weight The weight average molecular weight was measured using HLC-802A gel permeation chromatography manufactured by Toyo Sotaku Kogyo Co., Ltd., with two GMH-6 columns manufactured by the company in series. A refractometer was used as a detector, and tetrahydrofuran was used as a solvent. The sample used was a solid obtained by precipitating the component (A) polymer emulsion with methanol.

[Production of thermoplastic resin composition] 50% polybutadiene, 13% acrylonitrile, 37% styrene
Part A of ABS resin powder consisting of 30% acrylonitrile
, AS resin powder consisting of 70% styrene (weight average molecular weight 1.1 x 105 based on polystyrene) part b, polymer mixture C powder ((A) component polymer (A-type) and (B)
Component polymer (B-type) in the proportions shown in Tables 3 and 4) c part, commercially available polybutylene terephthalate resin ((manufactured by Mitsubishi Kasei Corporation, Novadol 5010) d part, 4,4'-isopropylidenebis[monophenyl-
Di-alkyl (C12-C15) phosphite] (manufactured by Adeka Argus Chemical Co., Ltd., MARK 1)
500) was mixed in a Henschel mixer and fed to VC-40 (vented single screw extruder) manufactured by Chuo Kikai Seisakusho Co., Ltd. to obtain pellets. Next, samples for measuring physical properties were prepared using the pellets, and physical properties were evaluated, and the results are shown in Tables 3 and 4.

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[Table 3]

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[Table 4]

The physical properties of Examples and Comparative Examples were determined by the following method. (1) Tensile yield point --- ASTM D-638
(2) Izod impact strength - ASTM D-256
(3) Vicat softening point---JIS K-6870
(4) Melt flow rate - JIS K-6874
(220℃, 10Kg load)

(5) Chemical resistance (environmental stress cracking resistance) A
The time taken to break when an STM D-638 type I dumbbell is given a 50 mm deflection, fixed to a jig, coated with acetic acid (special grade reagent), and left at a temperature of 23 degrees Celsius is expressed in minutes. In addition, >300 in Tables 3 and 4 means 3
Indicates that it does not break after 00 minutes.

(6) Paintability test: The test piece was a 120×1 piece obtained by injection molding.
A 20×2t (mm) square plate was used.・The coating method is shown in Table 5.・For the peeling of the grid-like paint, use a cross-cut tester to test the test plate that has been subjected to the above-mentioned paint treatment using a cross-cut tester.
Insert the cutting lines for the book. Next, apply duct tape,
Count the number of pieces of paint peeled off. - For paint crazing, observe the painted appearance of the test plate that has been subjected to the above painting treatment, and check with the naked eye whether there are any streak-like irregularities on the surface.

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[Table 5]

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[Effects of the Invention] As explained above, the thermoplastic resin composition produced according to the method of the present invention has excellent environmental stress cracking resistance and exhibits the effect of significantly improving the surface appearance after painting. Therefore, its industrial utility value is extremely large.

Claims (1)

[Claims] [Claim 1] 1. (A) A polymer of vinyl monomers, whose glass transition temperature exceeds 20 degrees Celsius, whose gel content is 10% or less, and whose solubility parameter is 9.
0 to 11.0 (cal/cc) 1/2, and a weight average molecular weight based on polystyrene of 2 x 105 or more and less than 40 x 105, emulsion of a polymer 20 to 90
(B) a homopolymer of an acrylic ester monomer or a copolymer of an acrylic ester monomer and another copolymerizable monomer, and the glass The transfer temperature is below 20 degrees Celsius and the gel content is 7
0% or less, and the solubility parameter is 8.4 to 9.
．． 8 (cal/cc) 1/2 polymer emulsion 1
0.5 to 50% by weight C of a polymer mixture of (A) and (B) obtained by separation from an emulsion with 0 to 80% by weight (as solid content of the polymer); 2. 3. rubber-containing styrenic resin 30-98.4% by weight; A thermoplastic resin composition comprising 0.1 to 20% by weight of a thermoplastic polyester resin.