JPH0623289B2 - Method for producing thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a thermoplastic resin composition which is excellent in environmental stress cracking properties and has an improved surface state of a molded article.

(Prior Art) When a rubber-containing styrenic resin is brought into contact with a chemical under stress, a crack is generated, and in a remarkable case, a phenomenon of breaking is observed. This phenomenon is called environmental stress crack phenomenon,
Alkanes, alkenes, which have low solubility in resins,
It is well known that remarkable observation is made with chemicals such as alcohol, carboxylic acid and ester.

The environmental stress cracking phenomenon occurs even when no external force is applied to the resin molded product, and the strain during molding that remains inside the molded product is released by contact with chemicals. It greatly restricts the use of resin.

It is known that i) the content of the rubber component, ii) the molecular weight of the resin component, and iii) the composition of the resin component as factors that affect the environmental stress crackability of the rubber-containing styrene resin.
i) increasing the content of the rubber component, ii) increasing the molecular weight of the resin component, iii) increasing the absolute value of the difference between the solubility parameter of the resin component and the solubility parameter of the chemical, or Methods such as introducing a bulky substituent into the molecular chain to increase the melt viscosity of the resin component are known, but in any case, the effect of improving the environmental stress crack resistance was insufficient in practice.

By the way, by the present inventors, by mixing the acrylic acid ester-based polymer with the rubber-containing styrene-based resin,
It has been reported that the environmental stress crack resistance of a rubber-containing styrene resin is dramatically improved (Japanese Patent Laid-Open No. 58-179).
257).

However, although the composition of the invention has a remarkable effect of improving the environmental stress cracking property, a defective phenomenon may be observed in the surface state of the injection molded product, and therefore the improvement has been required.
That is, when the composition of the invention is subjected to injection molding, a mica-like layered delamination phenomenon may be observed near the gate of the molded article, or an abnormal surface called a flow mark may be observed near the gate. In some cases, the design of the molded product could be impaired.

The poor phenomenon of these surface states is caused by the acrylic ester polymer particles dispersed in the rubber-containing styrene resin,
It is considered that this phenomenon is caused by flat deformation due to shear stress at the time of injection molding, and when the rubber-containing styrene-based resin having a high melt viscosity is used, the appearance of the defective phenomenon is particularly remarkable.

In order to prevent flat deformation of the acrylic ester polymer particles, it is effective to copolymerize a polyfunctional vinyl monomer during the polymerization of the acrylic ester polymer.

(Problems to be Solved by the Invention) However, in the case of an acrylic acid ester-based polymer obtained by copolymerizing a polyfunctional vinyl monomer such as divinylbenzene or ethylene glycol dimethacrylate, the phenomenon of poor surface condition Although the improvement is achieved, the gel content is high, and the effect of improving the environmental stress cracking resistance of the rubber-containing styrene resin is insufficient. Therefore, by using a polyfunctional vinyl monomer and a chain transfer agent together to produce an acrylic acid ester-based polymer having a low gel content and a branched structure, excellent environmental stress crack resistance is obtained. Moreover, it is possible to prepare a composition that gives a molded product in which the phenomenon of poor surface condition is suppressed, but the effect was unsatisfactory in practice.

An object of the present invention is to provide a thermoplastic resin composition that has improved the above-mentioned drawbacks of the prior art.

(Means for Solving Problems) The present invention will be described in brief. The present invention is an invention relating to a method for producing a thermoplastic resin composition, comprising (A) a polymer of a vinyl-based monomer, and a glass thereof. The transition temperature exceeds 20 ° C, the gel content is 10% or less, the solubility parameter is 8.0 to 10.0 (ca / cc) ^1/2 , and the polystyrene-based weight average molecular weight is 2 × 10 ⁵ or more. Emulsion 20-90 of polymer [(A) component polymer]
% (As polymer solids) and (B) homopolymer or copolymer of acrylic acid ester monomer, or copolymer of acrylic acid ester monomer and other copolymerizable monomer And its glass transition temperature is 20
10 to 80% by weight of an emulsion of a polymer [(B) component polymer] having a gel content of 70% or less and a solubility parameter of 8.4 to 9.8 (ca / cc) ^1/2. (As the solid content of the polymer) is mixed in an emulsion state, and then the polymer is separated into 0.5 to 50% by weight of the polymer composition and the rubber component content is 1 to 20% by weight. The high-impact polystyrene resin 50 to 9 in which 90% by weight or more of the monomer constituting the resin component is a styrene monomer
It is characterized in that it is mixed with 9.5% by weight.

The thermoplastic resin composition produced according to the method of the present invention has excellent resistance to environmental stress cracking, and is unlikely to cause a layered peeling phenomenon or a defective phenomenon of a molded article such as a flow mark.

Examples of the vinyl-based monomer that constitutes the polymer that is the component (A) of the present invention include styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, cyanostyrene,
Aromatic vinyl monomers such as chlorostyrene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, decyl acrylate, octadecyl acrylate, hydroxy Acrylic ester monomers such as ethyl acrylate, methoxyethyl acrylate, glycidyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, decyl methacrylate, octadecyl methacrylate, hydroxyethyl methacrylate, methoxyethyl Methacrylate Methacrylic acid ester monomers such as glycidyl methacrylate and 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 Such as vinyl halide monomers such as vinyl formate, vinyl acetate, vinyl propionate, vinyl decanoate, vinyl octadecanoate, etc., ethylene, propylene, 1-butene, isobutylene, 2-butene, etc. Olefin monomers, maleimides, N-methylmaleimides, N-ethylmaleimides, N-propylmaleimides, N-cyclohexylmaleimides, N-phenylmaleimides, N-toluylmaleimides and other maleimide monomers, and maleic anhydride and other acids. anhydrous Monomers, butadiene, isoprene, chloroprene, and other conjugated diene monomers, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, hexyl vinyl ether, decyl vinyl ether, octadecyl vinyl ether, phenyl vinyl ether, cresyl vinyl ether, glycidyl vinyl ether, and other vinyl ether monomers , Vinyl vinyl monomer such as methyl vinyl ketone and phenyl vinyl ketone, vinyl pyridine and the like, but not limited thereto.

The vinyl-based monomer that constitutes the component (A) polymer of the present invention may be a polyfunctional vinyl monomer. Examples of the polyfunctional vinyl monomer include divinylbenzene and ethylene glycol diethylene. (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, vinyl (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, pentaethylene glycol di (meth) acrylate, Naethylene glycol di (meth) acrylate, tetradecaethylene glycol di (meth) acrylate, eicosa ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, pentapropylene glycol di (meth) acrylate, nonapropylene glycol Examples include di (meth) acrylate, tetradecapropylene glycol di (meth) acrylate, eicosapropylene glycol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate. Here, for example, ethylene glycol di (meth) acrylate means ethylene glycol diacrylate or ethylene glycol dimethacrylate.

The component (A) polymer of the present invention has a glass transition temperature of 20 ° C.
It is necessary to exceed. A more preferable glass transition temperature is 30 ° C or higher. When the glass transition temperature of the component (A) polymer is 20 ° C. or lower, the weight ratio of the component (A) and the component (B)
It is industrially disadvantageous because it is difficult to handle the polymer composition C formed by mixing the component polymer as powder or pellets, and when mixed with a high-impact polystyrene resin, its heat resistance is improved. It is not preferable because it greatly decreases.

The component (A) polymer of the present invention has a composition of 8.0 to 10.0 (ca / cc) ^1/2
It is necessary to have a solubility parameter in the range of, and a more preferable range is 8.6 to 9.4 (ca / cc) ^1/2 . A thermoplastic resin obtained by mixing a high-impact polystyrene resin with a polymer composition C obtained by mixing a component (A) polymer having a solubility parameter outside the range of the present invention with a component (B) polymer. In the case of the composition, a layered peeling phenomenon and a surface defect phenomenon such as a flow mark appear on the molded product, which is not preferable.

In addition, the solubility parameter as used in the present specification refers to John Wiley End Sons Co., Ltd., New York City, 1975, edited by Brand Wrap and EHImmergut, Polymer Handbook (Polymer).
Handbook) Second Edition, using the solubility parameter values described on pages IV-337 to IV359, the solubility parameter δ _T of the copolymer is defined as the individual vinyl unit amount constituting the copolymer composed of m kinds of vinyl monomers. It is calculated by the following formula I from the solubility parameter δ _n of the homopolymer of the polymer and its weight fraction W _n .

For example, the solubility parameters of polybutyl acrylate and ethyl polyacrylate are respectively 8.8 (ca / cc) ^1/2 ,
Assuming 9.4 (ca / cc) ^1/2 , polybutyl acrylate 70
The solubility parameter of a copolymer composed of 30 wt% of polyethyl acrylate and 90 wt% of polyethyl acrylate is calculated to be 9.0 (ca / cc) ^1/2 .

The component (A) polymer of the present invention is required to have a polystyrene-based weight average molecular weight of 2 × 10 ⁵ or more.
Obtained by mixing a high-impact polystyrene resin with a polymer composition C obtained by mixing a component (A) polymer having a weight average molecular weight of less than 2 × 10 ^{5 on a} polystyrene basis with a component (B) polymer. In addition, the thermoplastic resin composition is not preferable because a layered peeling phenomenon and a surface defect phenomenon such as a flow mark appear on the molded product.

The polystyrene-based weight average molecular weight in the present specification is a weight average molecular weight determined by gel permeation chromatography, assuming that the component (A) polymer is polystyrene. That is, using polystyrene having a narrow molecular weight distribution and a known molecular weight as a standard substance, the relationship between the outflow peak volume of the gel permeation chromatogram and the molecular weight is obtained to prepare a calibration curve. Then, the gel permeation chromatogram of the component (A) polymer is measured, the molecular weight is determined from the outflow volume using the above calibration curve, and the weight average molecular weight is calculated according to a conventional method.

The component (A) polymer of the present invention needs to have a gel content of 10% or less. The gel content referred to in the present invention means that about 1.0 g of the component (A) polymer is precisely weighed ( _denoted as S ₀ g), placed in a basket made of a 400-mesh stainless wire net, and 100 g of methyl ethyl ketone. After being immersed in the solution and left at 5 ° C. for 24 hours, the basket was pulled up and air-dried at room temperature, and the weight S ₁ g of the component (A) polymer insoluble matter was measured. Then, the value calculated according to the following formula II was calculated. Say.

(S ₁ / S ₀ ) × 100 (%) ...... [II] (A) Component polymer having a gel content of more than 10% (B)
The thermoplastic resin composition obtained by mixing the polymer composition C mixed with the component polymer and the high-impact polystyrene resin is not preferable because the molded product has poor gloss.

The method for producing the component (A) polymer of the present invention is not particularly limited, and known techniques such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization can be arbitrarily applied, but the production by emulsion polymerization is industrial. Most advantageous to. Because, in part,
This is because the component (A) polymer and the component (B) polymer are mixed in an emulsion state in the present invention.
This is because emulsion polymerization can industrially easily produce a high-molecular weight polymer.

In producing the component (A) polymer of the present invention, the vinyl-based monomer is selected such that the glass transition temperature, gel content, solubility parameter and weight average molecular weight of the obtained component (A) polymer are the present invention. Although it is optional as long as the above condition is satisfied, the component (A) polymer is particularly preferably polystyrene for improving the layered peeling property.

It is possible to use a chain transfer agent for the purpose of controlling the molecular weight of the component (A) polymer. In particular, in the case of copolymerizing a polyfunctional vinyl monomer, a chain transfer agent may be used in combination to prepare a component (A) polymer having a branched structure and a low gel content. it can.

The chain transfer agent that can be used is not particularly limited, and examples thereof include octyl mercaptan, decyl mercaptan, dodecyl mercaptan, thioglycolic acid, ethyl thioglycolate, butyl thioglycolate, ethyl o-mercaptobenzoate, 1-naphthyl disulfide, and sulfur. Sulfur compounds, 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 or copolymer of an acrylic acid ester monomer, or a copolymer of an acrylic acid ester monomer and another copolymerizable monomer. However, here, the specific examples of the acrylic ester monomer are the same as the specific examples of the acrylic ester monomer described above as an example of the vinyl-based monomer constituting the component (A) polymer of the present invention. Is. Further, specific examples of the copolymerizable monomer that constitutes the component (B) polymer include, among the monomers listed above as examples of the vinyl-based monomer that constitutes the component (A) polymer,
This is the same as the specific example excluding the acrylic acid ester monomer.

Further, the component (B) polymer of the present invention may use a polyfunctional vinyl monomer or a chain transfer agent in the polymerization, and specific examples of the polyfunctional vinyl monomer and the chain transfer agent are:
Each is the same as the specific examples described above for the component (A) polymer.

The component (B) polymer of the present invention has a glass transition temperature of 20 ° C.
It is necessary to be the following. A more preferable glass transition temperature is 10 ° C or lower. Thermoplastic resin composition obtained by mixing a polymer composition C obtained by mixing a component (B) polymer having a glass transition temperature exceeding 20 ° C. with a component (A) polymer, and a high-impact polystyrene resin. Then, the environmental stress crack resistance is poor, which is not preferable.

The component (B) polymer of the present invention needs to have a gel content of 70% or less. The method for measuring the gel content is 100 g instead of 100 g of methyl ethyl ketone.
The procedure is the same as that of the component (A) polymer except that the above toluene is used, and it is calculated according to the above-mentioned formula II. A thermoplastic resin composition obtained by mixing a polymer composition C obtained by mixing a component (B) polymer having a gel content of more than 70% with a component (A) polymer into a high-impact polystyrene resin The environmental stress crack resistance is poor, which is not preferable.

The component (B) polymer of the present invention is required to have a solubility parameter in the range of 8.4 to 9.8 (ca / cc) ^1/2 . A more preferable numerical range is 8.6 to 9.6 (ca / cc) ^1/2 . The method for determining the solubility parameter is the same as that for the component (A) polymer, and is calculated according to the above-mentioned formula I.
The solubility parameter of the component (B) polymer is 8.4 (ca / cc)
^When it exceeds ^1/2 or 9.8 (ca / cc) ^1/2 , a polymer composition C prepared by mixing the component (B) polymer with the component (A) polymer is mixed with a high-impact polystyrene resin. The environmental stress crack resistance of the thermoplastic resin composition obtained in this way is poor, which is not preferable.

The method for producing the component (B) polymer is not particularly limited, and known techniques such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization can be arbitrarily applied, but the production by emulsion polymerization is industrially most advantageous. Is.

In the production of the component (B) polymer, the acrylic ester monomer or the copolymerizable monomer is selected such that the glass transition temperature, gel content, and gel content of the component (B) obtained are It is optional as long as the solubility parameter satisfies the requirements of the present invention.

In the present invention, 20 to 90% by weight of the component (A) polymer and 10 to 80% by weight of the component (B) are mixed in an emulsion state to obtain a polymer composition C, but the component (B) is used. When the content of the polymer is less than 10% by weight, the thermoplastic resin composition obtained by mixing the polymer composition C and the high-impact polystyrene resin is inferior in environmental stress crack resistance, and 8
If it exceeds 0% by weight, a layered delamination phenomenon, a surface defect phenomenon such as a flow mark, etc. appear in a molded article made of the thermoplastic resin composition, which is not preferable.

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

The emulsification method of the polymer is not particularly limited, and known techniques can be arbitrarily applied. For example, a method of removing a solvent after mixing and stirring a polymer solution with an emulsifier and water to form an emulsion, a method of mixing and stirring fine powder obtained by pulverizing a polymer with an emulsifier and water to form an emulsion, There is a method of pulverizing a polymer in the presence of an emulsifier and water to prepare an emulsion, but the method is not limited to this.

The particle size of the polymer of the component (A) polymer or the component (B) polymer in the emulsion is not particularly limited, but the area average particle size is preferably 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 taking the fraction of the particle diameter at which the particle diameter is d _i as f _i .

Σf _i d _i ³ / Σf _i d _i ² ...... [III] Especially when the area average particle size of the component (B) polymer exceeds 5 µ, the component (B) polymer is mixed with the component (A) polymer. A layered delamination phenomenon or a flow mark may occur in a molded product of a thermoplastic resin composition obtained by mixing the polymer composition C thus obtained with a high-impact polystyrene resin.

There are no particular restrictions on the type of emulsifier used for emulsion polymerization of the (A) component polymer or (B) component polymer, or for emulsifying the polymer, and an anionic surfactant, a cationic surfactant,
The amphoteric surfactant and the nonionic surfactant can be arbitrarily selected, but the anionic surfactant can be most advantageously used.

The mixing method of the component (A) polymer emulsion and the component (B) polymer emulsion is not particularly limited, and a fixed container type mixing device, a rotary container type mixing device, a pipeline mixer, a static mixer, etc. are used. And mixing can be performed.

The method for separating the polymer composition C from the mixed emulsion of the component (A) polymer emulsion and the component (B) polymer emulsion is not particularly limited, and the emulsion includes hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, etc. Electrolytes such as acids, sodium chloride, calcium chloride, aluminum chloride, sodium sulfate, magnesium sulfate,
Polyvinyl alcohol, polyethylene glycol, polyethylene glycol-polypropylene glycol block copolymer, a method of adding a precipitating agent such as a water-soluble polymer such as carboxymethyl cellulose, a method of freezing the emulsion and destructing the emulsion, a method of heating the emulsion in a high temperature gas. The method of spraying on can be exemplified.

The polymer composition C separated from the mixed liquid of the component (A) polymer emulsion and the component (B) polymer emulsion can be further supplied to a melt kneader for melt kneading. Examples of melt-kneading devices that can be used include Banbury mixers, intensive mixers, mixed extruders, co-kneaders, extruders, and rolls. Further, the melt-kneading device having a dehydration mechanism disclosed in Japanese Patent Publication No. 59-37021 can be used, but in the case of using the device, an emulsion and a precipitating agent are continuously supplied to the device. It is also possible to continuously perform mixing, emulsion breaking, dehydration, drying and melt kneading in the same device.

The high-impact polystyrene-based resin of the present invention refers to a rubber-containing styrene-based resin including a rubber component, a resin component, and a covalently bonded product of the rubber component and the resin component. Examples of the rubber component include polybutadiene, polyisoprene,
Conjugated diene rubbers such as polychloroprene, poly (butadiene-styrene), poly (butadiene-acrylonitrile), poly (butadiene-styrene-methylmethacrylate), poly (ethylene-propylene-4-ethylidenenorbornene), poly (ethylene-propylene) -Dicyclopentadiene) poly (ethylene-propylene-2,
5-norbornadiene) and other ethylene propylene rubbers. Further, as the monomer constituting the resin component, styrene, α-methylstyrene, vinyltoluene,
Styrene-based monomers such as t-butylstyrene, nitrile monomers such as acrylonitrile and methacrylonitrile,
(Meth) acrylic acid ester monomers such as methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, maleimide, N-methylmaleimide, N-ethylmaleimide,
Maleimide monomers such as N-cyclohexylmaleimide, N-phenylmaleimide and N-toluylmaleimide, maleic anhydride and the like can be mentioned, but 90% by weight or more of the monomers constituting the resin component are styrene monomers. Need to be.

The method for producing the high-impact polystyrene resin is not particularly limited, and known techniques such as bulk polymerization, bulk-suspension polymerization, suspension polymerization, solution polymerization and emulsion polymerization can be arbitrarily applied.

For example, for the purpose of adjusting the rubber component contained in the high-impact polystyrene-based resin, it is possible to mix the separately-polymerized resin component with the high-impact polystyrene-based resin. It does not have to have the same composition as the resin component obtained by the polymerization of the impact polystyrene resin. For example, high impact polystyrene obtained by polymerizing styrene in the presence of polybutadiene can be mixed with poly (styrene-maleic anhydride) obtained by another polymerization.

A covalent bond of a rubber component and a resin component, which is one of the essential structural units of a high-impact polystyrene-based resin, can be produced by a so-called graft polymerization method, but in the present invention, a known technique of the graft polymerization method can be arbitrarily applied. .

The rubber component content of the high-impact polystyrene-based resin needs to be 1 to 20% by weight. When the content of the rubber component is less than 1% by weight, the thermoplastic resin composition obtained by mixing with the polymer composition C has low impact resistance, and when it exceeds 20% by weight, the rigidity decreases.

In the present invention, 0.5 to 50% by weight of the polymer composition C and 50 to 99.5% by weight of the high impact polystyrene resin are mixed to produce a thermoplastic resin composition. More preferably, 2 to 40% by weight of the polymer composition C and 60 to 98% by weight of the high impact polystyrene resin are mixed. If the addition amount of the polymer composition C is less than 0.5% by weight, the resulting thermoplastic resin composition is inferior in environmental stress crack resistance, and is 50% by weight.
If it exceeds, the rigidity, heat resistance or impact resistance of the composition is deteriorated, which is not preferable.

The method for mixing the polymer composition C and the high-impact polystyrene resin is not particularly limited, and the desired thermoplastic resin composition can be manufactured by mixing both components in the powder or pellet state. Examples of the mixing device include a fixed container type mixing device such as a Henschel mixer, and a rotating container type mixing device such as a V-type blender and a tumbler, but are not limited thereto.

As a method for mixing the polymer composition C and the high-impact polystyrene resin, melt kneading can be exemplified.
Specific examples of the melt-kneading device used include a Banbury mixer, an intensive mixer, a mixed extruder, a cokneader, an extruder, and a roll.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

In addition, all the parts and% described in each example are weight standards.

Example 1 and Comparative Example 1 [Production of component (A) -Production of A-1 to A-15] 150 parts of pure water and 2 parts of potassium stearate were charged into an autoclave and heated to 50 ° C with stirring. An aqueous solution prepared by dissolving 0.005 part of ferrous sulfate heptahydrate 0.005 part, ethylenediamine tetraacetic acid tetrasodium salt dihydrate 0.01 part, and sodium formaldehyde sulfoxylate dihydrate 0.3 part in pure water 10 parts was poured. Added

Then, 4 parts of 100 parts of the monomer mixture liquid having the composition shown in Table 1 was added.
Continuously added over time. At the same time, potassium persulfate 0.05
An aqueous solution prepared by dissolving 25 parts of pure water 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, the temperature of the system was raised to 70 ° C., and the mixture was further stirred for 2 hours to complete the polymerization.

Table 2 shows the properties of the obtained component (A).

[Production of component (A) -Production of A-16 to A-17] 175 parts of pure water and 2 parts of potassium stearate were charged into an autoclave and heated to 70 ° C with stirring.

An aqueous solution in which 0.05 part of potassium persulfate was dissolved in 10 parts of pure water was added thereto, and 100 parts of a monomer mixed solution having the composition shown in Table 1 was continuously added over 4 hours.

After the addition of the monomer mixture is completed, lauroyl peroxide
0.1 part was added, and the mixture was further stirred at 70 ° C. for 2 hours to complete the polymerization.

Table 2 shows the properties of the obtained component (A).

[Production of component (A) -Production of A-18] 175 parts of pure water and 2 parts of potassium stearate were charged into an autoclave and heated to 50 ° C with stirring. An aqueous solution prepared by dissolving 0.005 part of ferrous sulfate heptahydrate 0.005 part, ethylenediamine tetraacetic acid tetrasodium salt dihydrate 0.01 part, and sodium formaldehyde sulfoxylate dihydrate 0.3 part in pure water 10 parts was poured. Added

Then, a mixed solution prepared by dissolving 0.2 part of diisopropylbenzene hydroperoxide in 100 parts of the monomer mixed solution having the composition shown in Table 1 was continuously added over 5 hours.

After the addition of the monomer mixture was completed, 0.1 part of diisopropylbenzene hydroperoxide was added, the temperature of the system was raised to 70 ° C., and the mixture was further stirred for 2 hours to complete the polymerization.

Table 2 shows the properties of the obtained component (A).

[Structure of component (B) -excluding B-15 and B-27] 120 parts of pure water and 2 parts of sodium dodecylbenzene sulfonate were charged into an autoclave and stirred while stirring 6
Heated to 5 ° C. Where, ferrous sulfate heptahydrate 0.005
Part, ethylenediamine tetraacetic acid tetrasodium salt dihydrate 0.01
Part, and an aqueous solution of 0.3 part of sodium formaldehyde sulfoxylate dihydrate dissolved in 10 parts of pure water were added.

Then, 2 parts of 100 parts of the monomer mixed solution having the composition shown in Table 3 was used.
0% was added to the autoclave and potassium persulfate 0.2%
Polymerization was initiated by adding 2.5 parts of an aqueous solution.

Simultaneously with the start of the polymerization, the remaining amount of the monomer mixture solution was continuously added over 4 hours. Simultaneously with the start of polymerization, an aqueous solution prepared by dissolving 0.05 part of potassium persulfate in 20 parts of pure water was continuously added over 6 hours. After the addition of the potassium persulfate solution was completed, the contents of the autoclave were cooled to complete the polymerization.

Table 4 shows the properties of the obtained component (B).

[Structure of component (B) -Production of B-15 and B-27] 140 parts of pure water and 2 parts of sodium dodecylbenzenesulfonate were charged into an autoclave and stirred for 7
Heated to 0 ° C.

An aqueous solution prepared by dissolving 0.05 part of potassium persulfate in 10 parts of pure water was added thereto, and 100 parts of a monomer mixed solution having the composition shown in Table 3 was continuously added over 4 hours.

After the addition of the monomer mixture, 0.1 part of diisopropylbenzene hydroperoxide was added, and the mixture was further added at 70 ° C for 2 hours.
Polymerization was completed by stirring for time.

Table 4 shows the properties of the obtained component (B).

The abbreviations of the long-chain bifunctional monomers used in Table 3 are as follows.

9G; nonaethylene glycol dimethacrylate 14G; tetradecaethylene glycol dimethacrylate 9PG; nonapropylene glycol dimethacrylate 9AG; nonaethylene glycol diacrylate [Production of polymer composition C] 50 parts of component (A) emulsion (of polymer) (As solid content) and 50 parts of component (B) emulsion (as solid content of polymer) are mixed in an emulsion state, and further polyethylene glycol-polypropylene glycol block copolymer (ethylene oxide weight fraction in the total molecule). A 10% aqueous solution of 80% and 0.7 part of polypropylene glycol molecular weight 1750-Pluronic F-68 manufactured by Asahi Denka Kogyo Co., Ltd. was added.

An aqueous solution obtained by dissolving 5 parts of calcium chloride / dihydrate in 400 parts of pure water was heated to 80 to 95 ° C., and the mixed emulsion described above was added thereto with stirring to deposit.

The obtained slurry was filtered, washed with water, and dried in an atmosphere at 70 ° C. to obtain a polymer composition C.

In addition, each physical property value was calculated | required by the following method.

(1) Glass transition temperature Component (A) or component (B) The emulsion obtained by dropping the emulsion in methanol is dried to obtain a DuPont measuring instrument.
It was measured using a 10 differential scanning calorimeter and a 990 thermal analyzer.

(2) Gel content The solid obtained by dropping the emulsion of the component (A) or the component (B) into methanol was dried. About 1.0 g thereof was precisely weighed, measured by the method described above, and calculated by the formula II. However, the solvent used was different between the component (A) and the component (B), methyl ethyl ketone was used for the component (A), and toluene was used for the component (B).

(3) Solubility Parameter The solubility parameter value [unit is (ca / cc) ^1/2 ] of each polymer used in the calculation of the solubility parameter in each example is as follows.

Butyl polyacrylate; 8.8 Ethyl polyacrylate; 9.4 Polymethylmethacrylate; 9.5 Polyacrylonitrile; 12.5 Polystyrene; 9.1 Polyvinyltoluene; 8.9 Poly (t-butylstyrene); 7.9 (4) Weight average molecular weight Toyo Soda Kogyo Co., Ltd. Two GMH-6 type columns manufactured by the same company were connected in series to HLC-802A type gel permeation chromatography for measurement. A refractometer was used as the detector, and tetrahydrofuran was used as the solvent.

The upper limit of measurement of the weight average molecular weight when using this device is 6 ×
10 ⁵ and Table 2 for samples exceeding 6 × 10 ^5.
> 6 was written in the corresponding column.

The sample used was a solid obtained by precipitating the component (A) emulsion with methanol.

[Production of Thermoplastic Resin Composition] 90 parts of high-impact polystyrene resin pellets composed of 7% polybutadiene and 93% polystyrene, and having a polystyrene weight average molecular weight of 2.15 × 10 ⁵ , and 10 parts of polymer composition C powder. The mixture was mixed and supplied to VC-40 (single screw extruder with vent) manufactured by Chuo Kikai Seisakusho Co., Ltd. to obtain pellets.

A molded product was prepared using the obtained pellets and physical properties were evaluated. The results are shown in Table 5, Experiment Nos. 1 to 45.

The measured physical properties of each example were obtained by the following methods.

(1) Tensile yield point …… ASTM D-638 (2) Izod impact strength …… ASTM D-256 (3) Vicat softening temperature …… JIS 6870 (4) Gloss …… JIS Z-8741 (5) Chemical resistance (Environmental stress crack resistance) ASTM D-638 Type I Danben is bent to 20 mm and fixed to a jig, coated with ethylene glycol monoethyl ether, and broken until left at 23 ° C at temperature. Represents the time in minutes. > 180 in the table is 1
It shows that it does not break after 80 minutes.

(6) Layered peeling and flow mark 2 by IS-80CN-V injection molding machine manufactured by Toshiba Machine Co., Ltd.
A strip-shaped molded product of 0 × 80 × 3 mm is prepared. The gate is located at the center of one side with a length of 20 mm, and the gate shape is an edge gate with a length of 2 mm having a rectangular cross section of 2 mm in the length direction and 1.5 mm in the thickness direction of the molded product. The mold has four cavities.

When the gate portion of the obtained molded product was manually broken, layer-like peeling might occur near the gate, and the degree of peeling was evaluated in the following manner in comparison with a standard sample.

A: Not observed at all B: A little observed C: Considerable observed D: Remarkably observed Experiment numbers 1-38 are Examples and numbers 39-45 are Comparative Examples.

In Comparative Example 39, the glass transition temperature of the component (A) deviates from the scope of the present invention, but the polymer composition obtained by mixing and precipitating the component (A) emulsion and the component (B) emulsion Since the solid of the substance C does not become powder at room temperature but has a lump form, an operational disadvantage is caused, for example, in the dehydration process of the precipitate, the washing process, the drying process, or the mixing process with the rubber-containing styrene resin.

In the experiments other than Comparative Example 39, the solid of the polymer composition C was in the form of powder and no operational trouble occurred.

As is clear from the comparative examples, when the weight average molecular weight or the solubility parameter of the component (A) deviates from the range of the present invention, the delamination phenomenon becomes remarkable, and when the glass transition temperature of the component (A) deviates from the range of the present invention. Heat resistance or operability during production is poor, and when the gel content of the component (A) deviates from the range of the present invention, gloss is poor, which is not particularly preferable. Further, if the solubility parameter, gel content or glass transition temperature of the component (B) deviates from the range of the present invention, the environmental stress crack resistance is deteriorated, which is not preferable.

Example 2 and Comparative Example 2 The A-1 emulsion and the B-1 emulsion produced in Example 1 were mixed in an emulsion state at a ratio shown in Table 6 (parts in the table are solid contents of the polymer). Represents the department as). Further, 7 parts of a 10% aqueous solution of Pluronic F-68 used in Example 1 was added to 100 parts of the solid content of the polymer mixture.

The obtained mixed emulsion was subjected to a precipitation treatment in the same manner as in Example 1 to obtain polymer compositions C-1 to C-7.

Next, 90 parts of the high-impact polystyrene resin pellets used in Example 1 and the polymer compositions C-1 to C-7
The powder was mixed with 10 parts and fed to a VC-40 type extruder to obtain pellets.

The pellets thus obtained were used for physical property evaluation in the same manner as in Example 1, and the results are shown in Table 7.

As is clear from Comparative Example 2, (B) in the polymer composition C
If the component content deviates from the lower limit of the range of the present invention, the environmental stress crack resistance is inferior, and if it deviates from the upper limit, the layered peeling phenomenon becomes remarkable, and both are not preferable.

Example 3 and Comparative Example 3 50 parts of A-1 emulsion (as solid content of polymer) and 50 parts of B-1 emulsion (as solid content of polymer) produced in Example 1 were in an emulsion state. Mix and then Pluronic F-6
7 parts of a 10% aqueous solution of 8 were added.

The obtained mixed emulsion was subjected to a precipitation treatment in the same manner as in Example 1 to obtain a powder of Example composition C.

Then, the powder of the polymer composition C was supplied to a VC-40 type extruder to obtain pellets. The obtained pellets of the polymer composition C and the high-impact polystyrene resin pellets used in Example 1 were obtained. Table 8
The mixture was mixed at the ratio shown in Table 1 and supplied to a VC-40 type extruder to obtain a thermoplastic resin composition pellet.

The physical properties of the obtained pellets were evaluated in the same manner as in Example 1, and the results are shown in Table 3.

As is clear from Comparative Example 3, when the addition amount of the polymer composition C deviates from the lower limit of the range of the present invention, the environmental stress resistance of the obtained thermoplastic resin composition is poor, and when it deviates from the upper limit, heat resistance Is lowered, which is not preferable.

(Effects of the Invention) As described above, the thermoplastic resin composition produced according to the method of the present invention is excellent in environmental stress crack resistance, and the layered delamination phenomenon of the obtained molded article is significantly suppressed. It has a remarkable effect.

Claims (1)

[Claims] 1. A polymer of vinyl monomer (A), which has a glass transition temperature exceeding 20 ° C., a gel content of 10% or less, and a solubility parameter of 8.0 to 10.0 (ca / cc).
20 to 90% by weight of an emulsion of a polymer which is ^1/2 and has a polystyrene-based weight average molecular weight of 2 × 10 ⁵ or more.
(As the solid content of the polymer) and (B) a homopolymer or copolymer of an acrylic acid ester monomer, or a copolymer of an acrylic acid ester monomer and another copolymerizable monomer. , Its glass transition temperature is 20
10 to 80% by weight of a polymer emulsion having a gel content of 70% or less and a solubility parameter of 8.4 to 9.8 (ca / cc) ^1/2 (as solid content of polymer) And 50% by weight of a polymer composition C obtained by separating the polymer after mixing and in an emulsion state, and the content of the rubber component being 1 to 20% by weight, and constituting a resin component. A method for producing a thermoplastic resin composition, wherein 90% by weight or more of a monomer is mixed with 50 to 99.5% by weight of a high-impact polystyrene resin which is a styrene monomer.