JPH11217411A - Rubber-modified styrene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve falling ball impact strength, tensile strength and flowability by dispersing butadiene-based rubber particles in a matrix of a certain styrene-acrylic copolymer. SOLUTION: 50-90 wt.% of a styrene-based monomer, 10-50 wt.% of an acrylonitrile-based monomer and/or a (meth)aerylate-based monomer, and optionally, 0-40 wt.% of another copolymerizable, unsaturated vinyl monomer are polymerized by graft polymerization at 20-100 deg.C for 2-10 hr in the presence of 3-30 wt.% of butadiene-based rubber particles having a particle size and dispersion coefficient defined by formula: D.P=4×(1/L)+10A+50B+50C (wherein D.P is a dispersion coefficient of 53-65; A is a fraction of rubber particle having a particle size of 0.12 μm or less to total rubber particles of 0.1-0.85; B is a fraction of rubber particle having a particle size of 0.12-0.5 μm to total rubber particles of 0.05-0.85; C is a fraction of rubber particle having a particle size of 0.5 μm or more to total rubber particles of 0.01-0.2; and L is an average distance between the rubber particles (μm)).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a specific rubber-modified styrenic resin composition, which has particularly excellent falling ball impact strength, high tensile strength, good fluidity, and whose molded product is coated. Even after, it relates to a resin composition that retains excellent low-temperature falling ball impact strength

[0002]

2. Description of the Related Art A styrene-based resin composition is a kind of impact-resistant resin obtained by dispersing a rubbery graft copolymer in a styrene-based copolymer matrix. Compositions are known. In application, it is used for housings of home appliances and molded products for automobile interiors. This kind of resin material always has the characteristics such as impact resistance and high tensile strength, but ABS resin is a typical material that meets this requirement. Styrene resin composition,
It has been widely used for a long time. In recent years, the appearance and added value of products have become increasingly important, and it has become common practice to apply coatings to molded products. The strength is greatly reduced, especially the falling ball impact strength at low temperatures. It is generally said that the impact resistance of a styrene resin is related to the rubber content of the resin or the average particle size of the rubber.
Increasing the rubber content or the average particle size improves the impact strength, but may adversely affect the stiffness, flowability and glossiness of the resin. It has been a long-standing problem in the technical field to create a resin material that has strength and that retains excellent falling ball impact strength at low temperatures even after molding and coating.

[0003] The main object of the present invention is to provide a rubber-modified styrene resin having excellent falling ball impact strength, high tensile strength and high gloss, and also having excellent falling ball impact strength at a low temperature even after molding and coating. It is to provide a composition.

[0004]

SUMMARY OF THE INVENTION The present invention has a kind of excellent falling ball impact strength, high tensile strength, good gloss, and
Even after coating the molded article, to provide a rubber-modified styrenic resin composition possessing excellent low-temperature ball impact strength,
It is formed by dispersing butadiene-based rubber particles in a styrene-based copolymer matrix.

That is, the present invention provides an acrylonitrile monomer and / or a (meth) acrylate monomer.
A monomer mixture containing 10 to 50% by weight, 50 to 90% by weight of a styrene monomer, and 0 to 40% by weight of another copolymerizable unsaturated vinyl monomer which is added as needed. In a resin composition containing a styrene-acrylic copolymer matrix obtained by polymerization and butadiene rubber particles dispersed in the matrix, the particle diameter and dispersion coefficient of the rubber particles satisfy the following formula: A rubber-modified styrenic resin composition characterized by the following. D. P = 4 × (1 / L) + 10A + 50B + 50C [D. P is the dispersion coefficient, whose value is in the range of 53 to 65,
A is a fraction occupied by rubber particles having a particle diameter of 0.12 μm or less in the whole rubber particles, and the value is between 0.1 and 0.85;
Is the fraction occupied by rubber particles having a particle diameter of more than 0.12 μm and less than 0.5 μm in the whole rubber particles, and the value is between 0.05 and 0.85. In percent, the value is between 0.01 and 0.2, and L is the distance (μm) between the average rubber particles. ].

A rubber-modified styrene system having the above-mentioned composition and at the same time having characteristics such as high falling ball impact strength, high tensile strength, and high glossiness, and maintaining good falling ball impact strength at a low temperature even after coating a molded article. A resin composition can be manufactured.

The styrenic copolymer of the present invention is 50 to 90% by weight as a total of 100% by weight, and 10 to 50% by weight of an acrylonitrile monomer and / or a (meth) acrylate monomer. %, And 0 to 40% by weight of other copolymerizable unsaturated vinyl monomers optionally added
It is composed of Further, the average molecular weight of the styrenic copolymer of the present invention is between 40,000 and 300,000, preferably 60,00.
0 to 250,000.

The styrene monomer used in the present invention is
Styrene, α-methylstyrene, α-chlorostyrene,
pt-butylstyrene, p-methylstyrene, o-chlorostyrene, p-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, 2,4,6-tribromostyrene, 2,5- Examples thereof include dibromostyrene and divinylbenzene, among which styrene or styrene and α-methylstyrene are preferably used in combination.

Acrylonitrile monomers include acrylonitrile and methacrylonitrile, among which acrylonitrile is preferred. On the other hand, as (meth) acrylate-based monomers, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate,
Butyl (meth) acrylate, benzyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylic acid Examples include glycidyl, α- (meth) acryloxypropyltrimethoxysilane, dimethylaminoethyl (meth) acrylate, and among them, methyl methacrylate is particularly preferred.

The copolymerizable unsaturated vinyl monomers used in the present invention include the following. For example, maleimide monomers, acrylic acid, methylacrylic acid, maleic anhydride and the like.

The maleimide monomers include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide,
N-octylmaleimide, N-dodecylmaleimide, N
-Cyclohexylmaleimide, N-phenylmaleimide, N-2,3-dimethylphenylmaleimide, N-
2,4-dimethylphenylmaleimide, N-2,3-diethylphenylmaleimide, N-2,4-diethylphenylmaleimide, N-2,3-dibutylphenylmaleimide, N-2,4-dibutylphenylmaleimide, N-
2,6-dimethylphenylmaleimide, N-2,3-dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide, N-2,4,6-tribromophenylmaleimide and the like Yes, N-phenylmaleimide is the best.

The butadiene rubber particles dispersed in the styrene copolymer matrix are rubbery graft copolymers. The rubbery graft copolymer is prepared from the butadiene rubber in the presence of the butadiene rubber in the presence of a mixture of various monomers, ie, a styrene monomer, an acrylonitrile monomer and / or (meth) acrylic acid. By polymerizing ester monomers and, if necessary, unsaturated vinyl monomers copolymerizable therewith.

A typical method for producing a rubbery graft copolymer is to polymerize a mixture of the various monomers in an emulsified state in the presence of an emulsion of a butadiene rubber (usually crosslinked). That is, the emulsion polymerization method, a solvent-soluble butadiene-based rubber, a mixture of the various monomers as described above and an organic solvent, if necessary, to prepare a solution of the butadiene-based rubber, and a method of polymerizing the solution, that is, a bulk or solution. There is a polymerization method.

The butadiene rubber used when the rubbery graft copolymer is prepared by an emulsion polymerization method comprises 100 to 50% by weight of 1,3-butadiene and a copolymerizable monomer having a -CH = C <group. Consists of ~ 50% by weight. For example, butadiene-unsaturated nitrile compounds such as polybutadiene, butadiene-styrene, butadiene-vinyl aromatic copolymer such as butadiene-vinyltoluene copolymer, butadiene-acrylonitrile copolymer, and butadiene-methacrylonitrile copolymer Butadiene-alkyl acrylate copolymers such as polymers, butadiene-methyl acrylate copolymer, butadiene-ethyl acrylate copolymer, butadiene-butyl acrylate copolymer, butadiene-2-ethylhexyl acrylate copolymer, There are a butadiene-alkyl methacrylate copolymer such as a butadiene-methyl methacrylate copolymer and a butadiene-ethyl methacrylate copolymer, and a tertiary or higher copolymer having 50% by weight or more of butadiene. As the butadiene rubber, those having a glass transition temperature of 0 ° C. or less are used.

The above-mentioned butadiene rubber is produced by a polymerization method such as emulsification, solution or lump. When the emulsion is prepared by an emulsion polymerization method, a monomer is directly subjected to emulsion polymerization to produce a rubber emulsion having a required rubber particle size. Alternatively, after the monomer is adjusted to a rubber emulsion having a smaller particle size by emulsion polymerization, further, by a freezing method or a homogenizer treatment method or an additive coagulation method, the rubber particles having the small particle size are coagulated and enlarged, Particles having a required rubber particle size are prepared and prepared for the next graft copolymerization reaction. In the additive coagulation method, an additive to be used is an acidic substance such as acetic anhydride, hydrochloric acid, sulfuric acid, or an inorganic salt substance such as sodium chloride, potassium chloride, calcium chloride, or magnesium chloride, or a methacrylic acid-acrylate copolymer ( For example, polymer aggregates containing a carboxyl group such as methacrylic acid-butyl acrylate copolymer) and the like.

In the production of the butadiene rubber emulsion of the present invention, a rubber latex having a desired particle size distribution can be produced by changing the method of adding an emulsifier, the reaction rate, and the conversion of a monomer.

The above rubbery polymer may be partially crosslinked. The amount of the crosslinking agent is 0 to 2% by weight based on the rubber-like polymer
Thus, any crosslinking agent generally used for butadiene rubbers can be used. For example, Divinyl benze
n), diallyl maleate, diallyl fumarate, allyl acrylate, tetraethylene glycol dimethacrylate and the like. The gel content of the butadiene rubber emulsion is related to the degree of swelling of the rubber, but is not particularly limited. But the gel content is 30-90%
Is most suitable, while the degree of rubber swelling using benzene as a solvent is most preferably 20 to 60.

Further, the rubbery graft copolymer can be used in the presence of a styrene-based monomer in the presence of butadiene-based rubber.
It is obtained by graft polymerization of 90% by weight, 10 to 50% by weight of an acrylonitrile monomer and / or a methacrylic acid ester monomer, and 0 to 40% by weight of another copolymerizable monomer. . The preparation of the graft copolymer is carried out using a known graft copolymerization technique, and the monomer mixture is subjected to a graft polymerization reaction in the presence of the rubber-like polymer, and the styrene-based polymer is grafted to the rubber-like polymer by a chemical bond. Join. The proportion of butadiene rubber in the rubbery graft copolymer is usually 20 to 90% by weight.

Depending on the ratio of the monomer to the rubbery polymer and the polymerization conditions, a necessary degree of graft polymerization of the rubbery graft copolymer can be obtained. Usually, a predetermined graft ratio can be obtained depending on a combination of various factors such as polymerization conditions during the graft polymerization reaction, the chemical structure of the rubber-like polymer, the rubber particle size, the charging speed of the monomer, and the chain transfer agent. Usually, rubber particles having an average particle size of 0.05 to 0.5 μm are used.

In the above-mentioned graft polymerization reaction, the initiator to be added is usually in the range of 0.01 to 5.0% by weight based on the monomer, and the best amount is 0.1 to 3.0% by weight. The addition amount is determined according to the polymerization reaction of the monomer, but the initiator may be increased to facilitate the graft polymerization reaction. The molecular weight of the graft polymer can be adjusted by controlling the reaction temperature and / or by adding a small amount of a conventional molecular weight modifier.
Examples of the molecular weight modifier include mercaptans, halides and terpenes. Specific examples include n-dodecyl mercaptan, carbon tetrabromide, terbinolene and α-methylstyrene dimer (2,4-diphenyl-4).
-Methyl-1-pentene) and the like.

In this graft polymerization reaction, the monomer mixture is usually added continuously or stepwise during the polymerization reaction, and it is desirable to add the initiator continuously or stepwise. As the initiator, various initiators for an emulsion free radical polymerization reaction are used. For example, peroxides and azo compounds may be added in a primary, continuous or stepwise manner. Suitable peroxide initiators include, for example, alkali metal peroxides, persulfates, perborates, peracetates, percarbonates, hydrogen peroxide, and the like, as well as other oil-soluble initiators. For example, di-tert
-Butyl peroxide, benzoyl peroxide, lauroyl peroxide, oleyl peroxide, cumene hydroperoxide, tetrabutyl hydroperoxide,
Other types of free radical catalysts are also used (eg, light irradiation, etc.).

The graft polymerization reaction of the rubber latex and the monomer mixture is agitated in an inert gas atmosphere at a temperature of 20 ° C to 100 ° C. Or pressurize to 0-100P.SIG. The polymerization time usually requires 2 to 10 hours. Of these, 4 to 9 hours are optimal.

In the present invention, when the rubber-like graft copolymer is produced by bulk or solution polymerization, the rubber-like graft copolymer is prepared in an amount of 3 to 30% by weight, and a styrene-based monomer based on the total monomer. 50-90% by weight of the body, 97-50% by weight of an acrylonitrile monomer and 10-50% by weight of a methacrylate monomer and 0-40% by weight of other copolymerizable monomers Is used. According to the production method, a rubbery polymer is dissolved in a monomer or a mixture of a monomer and a solvent in advance, and the resulting mixture is put into a reaction tank by a pump to perform a graft polymerization reaction.
The reactor is made up of many combinations, and the use of a kettle type reactor equipped with a strong stirrer is generally preferred, and the monomer and rubbery polymer are mixed well and polymerized in a continuous manner. A reactor with a tower-shaped pipe may be used.
During the reaction, a chain transfer agent is appropriately added. For example, tert-
Control the molecular weight with dodecyl mercaptan.

The butadiene rubber used for this purpose includes polybutadiene and butadiene copolymer. Representative examples of polybutadiene include a high cis type (Hi-cis) and a low cis type (Low-cis). Cis / Viny in high cis type
The typical weight composition of l is 94-98% / 1-5%, other compositions are trans-structure. Its Mooney viscosity is 20 ~ 12
Between 0, a molecular weight range of 100,000 to 800,000 is preferred. The typical composition of Cis / Vinyl in low-cis type rubber is 20-40% /
1-20%, other composition is trans structure, its Mooney viscosity is between 20-120. Other suitable butadiene rubbers include acrylonitrile / butadiene rubber and styrene / butadiene rubber. The styrene / butadiene rubber conforming to the present invention has a polymerization mode of di-block copolymer, tri-blo
ck) copolymerization, random copolymerization, or star-shaped (st
ar type) copolymerization. The weight ratio of styrene / butadiene rubber is preferably from 5/95 to 80/20, and the molecular weight range is preferably from 50,000 to 600,000. The average particle size of the rubber particles in the rubbery graft polymer produced by the bulk or solution polymerization method is usually 0.5 to 10 μm, preferably 0.8 to 6 μm.
It is.

The distribution of the rubber particle diameter in the present invention is represented by a fraction, wherein the fraction A of the rubber particles having a particle diameter of 0.12 μm or less to the whole rubber particles is 0.1 to 0.85, preferably 0.12 to 0.8, and 0.12 to 0.8. The fraction B of the rubber particles of more than μm and less than 0.5 μm with respect to the whole rubber particles is 0.05 to 0.85, and further 0.1 to 0.82
The fraction C of the rubber particles having a particle diameter of 0.5 μm or more with respect to the whole rubber particles is 0.01 to 0.2, preferably 0.02 to 0.14. When the fraction of the rubber particles is outside the scope of the present invention,
The balance between the falling ball impact strength, the tensile strength and the glossiness of the surface during molding is not good.

The dispersion coefficient (DP) of the present invention is shown below. D. P = 4 × (1 / L) + 10A + 50B + 50C where L is the distance (μm) between the average rubber particles. When the value of P is good in the range of 53 to 65 and the dispersion coefficient is less than 53, the low-temperature falling ball impact strength (painted product) of the molded product is not good,
Further, when the dispersion coefficient (DP) value is larger than 65, the falling ball impact strength after coating of the molded product is deteriorated, and the balance between the tensile strength and the surface glossiness of the resin is also deteriorated. More specifically, the distance (L) between the average rubber particles in the present invention was determined by taking a thin film obtained by staining the resin composition with osmium tetroxide (OsO ₄ ) using a transmission (TEM) electron microscope and photographing with a magnifying power.
After staining a 50,000 × electron micrograph with osmium tetroxide, the rubber part is dyed black and the hard styrene copolymer is not dyed, forming a white phase. Next, for one photo of 12cm x 12cm area, first, on one side of this photo,
Draw five parallel straight lines at 2 cm intervals. Next, in a direction perpendicular to the above, five straight lines, a total of ten straight lines, are similarly drawn at intervals of 2 cm. Next, first, the average distance Li between the rubber particles for one straight line in the straight line is determined by the following equation.

[0027]

(Equation 1)

Further, similarly, the average distance Li between the rubber particles is determined for a total of 10 straight lines (including the first straight line). Next, the average distance Lj between the rubber particles of one photograph is obtained by the following equation.

[0029]

(Equation 2)

Further, for 15 micrographs at different positions,
By calculating each Lj and finally averaging 15 Ljs, the average distance L between rubber particles defined in the present invention is obtained.

The percentage of the number of rubber particles in the resin composition of the present invention was measured by a transmission electron microscope at a magnification of 25,000 times (2,000 or more rubber particles). Is determined, n1 is the number of particles having a particle size of 0.12 μm or less, n2 is the number of particles having a particle size of 0.12 to 0.5 μm, and n3 is the number of particles having a particle size of 0.5 μm or more. That is, N (total number of rubber particles) = n1 + n2 + n3 The fraction of rubber particles having a particle diameter of 0.12 μm or less is A = (n1 /
N) The fraction of rubber particles having a particle diameter of more than 0.12 μm and less than 0.5 μm is B =
(N2 / N) The fraction of rubber particles having a particle diameter of 0.5 μm or more is C = (n3 /
N).

In the rubbery graft copolymer used in the present invention, the rubber component accounts for 15 to 80% by weight, preferably 45 to 75% by weight. The proportion of the styrene copolymer grafted onto the rubber and the rubber component is proportional to the graft ratio, and the graft ratio is 20 to 150% by weight, preferably 25 to 80% by weight based on the rubber weight.

In order to control the rubber content in the resin composition of the present invention, an appropriate amount of a styrene copolymer is mixed. Generally speaking, the content of the rubber component in the resin composition of the present invention is 2 to 50% by weight, preferably 7 to 35% by weight, particularly preferably 10 to 25% by weight.
% By weight is preferred. When the content of the rubber component in the rubber-like graft copolymer is within this range, the composition of the present invention is constituted as it is, so that it is not necessary to separately mix a styrene-based copolymer.

The styrene copolymer forming the matrix is obtained by combining the free styrene copolymer in the rubbery graft copolymer with the styrene copolymer mixed to adjust the rubber content. Means

Other additives can be added to the rubber-modified styrenic resin composition of the present invention, if necessary. As additives, for example, antioxidants, plasticizers, processing aids,
UV stabilizers, UV absorbers, fillers, reinforcing agents, colorants, lubricants, antistatic agents, flame retardants, flame retardant aids, heat stabilizers,
There are coupling agents or other additives. The above-mentioned additives can be usually added during the polymerization reaction, after the reaction, before coagulation, or in various processes such as extrusion kneading.

As the antioxidant, usually, a phenolic antioxidant, a thioether-based antioxidant, a phosphorus-based antioxidant, a chelating agent and the like are used, and the addition amount of the phenol-based antioxidant is 0.005 to 2.0% by weight. % Is preferred, and octadecyl (3,5-di-tert-butyl-4
-Hydroxyphenyl) propionate, triethylene glycol bis [3- (3-tert-butyl-5-methyl-
4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2-tert-butyl-6- (3-tert-butyl-2-hydroxy -5
-Methylbenzyl) -4-methylphenyl acrylate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-thiobis (4-methyl-
6-tert-butylphenol), 2,2'-thio [diethyl-bis-3- (3,5-di-tert-butyl-4-hydroxyphenyl)] propionate, 2,2'-oxamidobis- [ethyl-3 -(3,5-ditert-butyl-4-hydroxyphenyl) propionate].

The addition amount of the thioether-based antioxidant is 0.005
To 2.0% by weight, and typical examples thereof include distearyl thiodipropionate, dipalmityl thiodipropionate, pentaerythritol-tetrakis- (β-
Dodecylmethyl-thiopropionate), dioctadecylthioether and the like.

Phosphite-based antioxidants include phosphite-based and phosphonite-based antioxidants, and the added amount thereof is preferably 0.015 to 2.0% by weight. Representative examples thereof include tris (nonylphenyl) phosphite and tris-phosphite. Decylphosphite, cyclic neopentanetetraylbis (octadecylphosphite), 4,4-butylidenebis (3-methyl-6-tert-butylphenyl-ditridecylphosphite), tris (2,4-tert-butylphenyl) ) Phosphite or tetrakis (2,4-
The amount of the chelating agent such as tert-butylphenyl) 4,4′-biphenylenediphosphonite), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.01 to 2.0. % By weight, and typical examples include bisbenzoyl metal and sodium ethylenediaminetetraacetate.

The total amount of the above-mentioned antioxidants is usually 0.03 to 3.0% by weight based on the rubber-modified styrenic resin composition of the present invention.

Representative examples of the lubricant include metal soaps such as calcium stearate, magnesium stearate, and lithium stearate, ethylene bisstearyl amide, methylene bis stearyl amide, palmitic amide, butyl stearate, cetyl stearate, and polypropylene. Glycol monostearate, compounds such as behenic acid and stearic acid, silicone oil, polyethylene wax, ethylene-vinyl acetate wax and the like, the total amount of which is usually based on the rubber-modified styrene resin composition of the present invention. 0.03 to 5.0% by weight. There are also methyl methacrylate-based processing aids for improving extrudability and thermoformability.

Note that typical ultraviolet absorbers include benzotriazole compounds and benzophenone compounds, and typical ultraviolet stabilizers include hindered amine compounds. Usually, an ultraviolet absorber and an ultraviolet stabilizer are used. It is preferred to use When these are added, the total amount is usually 0.02 to 2.0% by weight based on the rubber-modified styrenic resin composition of the present invention.

In order to improve the properties of the resin such as discoloration due to ultraviolet irradiation or deterioration of the properties of the resin, for example, a combination of both a hindered amine-based ultraviolet stabilizer and a cyanoacrylic acid-based ultraviolet absorber is preferably used.
Uvinul 4050H (0.02 to 1.0% by weight) / Uninul 3035
(0.02 to 1.0% by weight).

Representative examples of the antistatic agent include low molecular weight compounds such as tertiary amine compounds and quaternary ammonium salt compounds, and polyamide polyethers and 3-chloro-1,2-propylene oxide polymers. Permanent antistatic polymeric materials.

Typical fillers include calcium carbonate, silica, mica and the like. Typical reinforcing agents include glass fiber, carbon fiber, and various whiskers.
r).

Typical coloring agents include titanium oxide,
Examples include iron oxide, carbon black, and phthalocyanine blue.

Representative flame retardants or flame retardant aids include decabromodiphenyl ether, tetrabromobisphenol A, brominated polystyrene oligomer, brominated epoxy resin, hexabromocyclododecane, chlorinated polyethylene, triphenyl phosphate, resorcinol. Examples include bis (diphenyl phosphate), red phosphorus, antimony oxide, aluminum hydroxide, magnesium hydroxide, zinc borate, melamine, melamine isocyanurate, silicone powder, polytetrafluoroethylene powder, and expandable graphite.

Representative heat stabilizers include dibutyltin maleate, zeolite-based stabilizers, basic magnesium aluminum hydroxide carbonate and the like. Further, as a thermal discoloration inhibitor, there is a low molecular weight styrene-maleic anhydride copolymer, the amount of addition of this is usually 0.1 to 1.0 of the rubber modified styrene resin composition of the present invention.
% By weight.

Typical coupling agents include silane, titanate and zirconate compounds.

In order to modify the styrenic resin composition of the present invention, a polymer additive having a suitably high molecular weight may be used. Examples of the polymer additive include rubbers other than butadiene rubber, For example, rubber-modified styrene resins such as AES resin and AAS resin made using EPDM or butyl acrylate rubber, maleic anhydride-styrene copolymer, styrene-phenylmaleimide copolymer,
Styrene having a phenylmaleimide content exceeding 40% by weight
Acrylonitrile-phenylmaleimide copolymer, copolymer of styrene-acrylonitrile-maleic anhydride copolymer imidized with aniline, crosslinked rubber without grafting operation, such as acrylonitrile-butadiene rubber, vinyl chloride resin, polymethyl methacrylate Resin, polycarbonate resin, polyamide resin, polybutylene terephthalate, styrene-based thermoplastic elastic material, various compatibilizers and the like. The compounding amount of these polymers is usually 3 to 200 parts by weight based on 100 parts by weight of the rubber-modified styrenic resin composition of the present invention.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to explain the present invention in more detail, examples and physical property measurement examples will be described below. However, the numbers of the following composition components and the like all indicate parts by weight,% by weight, etc., unless otherwise indicated. Also. The scope of the present invention is not limited to these examples.

<Production Example><Production Example I-1> Production of Butadiene Rubber Emulsion (A-1) The following raw materials are put into a reaction vessel equipped with a stirring device, a heating device, and a raw material supply pipe.

[0052] After adding the raw materials, the reaction is continued at 70 ° C. for 12 hours, and then the reaction is terminated. After the reaction, the conversion of the produced rubber emulsion is 93% or more, and the unreacted butadiene after the polymerization is removed by a steam distillation method. The emulsion has a solid content of 40%, the rubber particle size distribution of the polymer is 0.06 to 0.10 μm, and is hereinafter abbreviated as A1.

<Production Example I-2> Production of Butadiene Rubber Emulsion (A-2) In the formulation amount of Production Example I-1, 20% of monomer, 20% of potassium oleate and potassium persulfate aqueous solution were The reaction was performed in a primary addition manner, and the remaining 80% of the monomer, 80% of potassium oleate, and aqueous solution of potassium persulfate were continuously added for 5 hours, and the reaction was continued at 65 ° C. for 9 hours, followed by cooling. To terminate the reaction. The rubber emulsion conversion after the reaction is 85% or more. Unreacted butadiene after polymerization is removed by a distillation method using steam. The solid content of the emulsion is 39%, the rubber particle size distribution in the polymer is 0.08 to 0.12 μm, and is hereinafter abbreviated as A2.

<Production Example II> Synthesis of Copolymer Emulsion (II) Containing Carboxyl Group Having Enlargement Action The ingredients are as follows.

Component parts by weight n-ethyl acrylate 85.0 methacrylic acid 15.0 tert-dodecyl mercaptan 0.3 potassium oleate 2.0 sodium dioctyl sulfosuccinate 1.0 cumene hydroperoxide 0.4 sodium formaldehyde-modified sodium sulfoxylate 0.3 deionized water 200.0 And polymerized at 70 ° C. for 4 hours. With a conversion of more than 93%, a pH value of 6.1,
A rubber having an average particle size of 0.07 μm is obtained.

<Production Example III> Production of Enlarged Rubber Emulsion (C) 1.5 parts by weight (solid content) of 100 parts by weight (solid content) of butadiene rubber emulsion (A2) was stirred for 5 seconds while stirring. Copolymer emulsion containing an active carboxyl group (II)
And the inorganic electrolyte Na ₂ SO ₄ , followed by continuous stirring for 30 minutes, to obtain an enlarged rubber emulsion having a rubber particle size distribution of 0.28 to 0.45 μm. The following is abbreviated as C.

<Production Example IV-1) Production of Rubbery Graft Copolymer (D1) A graft polymerization reaction is performed according to the following formulation in a reactor purged with nitrogen gas. Ingredients by weight Butadiene rubber emulsion (A1) (solid content) 100.0 Styrene 75.0 Acrylonitrile 25.0 Potassium oleate 2.0 Tert-dodecylmercaptan 0.6 Cumene hydroperoxide 1.4 Ferrous sulfate solution (0.2%) 3.0 Sodium formaldehyde-modified sodium sulfoxylate (10%) 3.0 Ethylenediaminetetraacetic acid solution (0.25%) 20.0 Distilled water 200.0 Styrene / acrylonitrile in the above formulation is added in a continuous addition system within 5 hours, polymerized in a reaction tank, and the obtained rubber graft emulsion is coagulated with calcium chloride. Then, by drying until the water content becomes 2% or less after dehydration, a rubbery graft copolymer (D1) by an emulsion polymerization method can be produced. Its rubber content is 50% by weight.

<Production Example IV-2) Production of Rubbery Graft Copolymer (D2) Using the butadiene-based rubber emulsion (A2) obtained in Production Example I-2, a graft polymerization reaction was directly performed with the following composition. When,
A rubbery graft copolymer (D2) obtained by an emulsion polymerization method having a rubber content of 50% by weight is obtained. Ingredients by weight Synthetic rubber latex (A2) (solid content) 100.0 Styrene 75.0 Acrylonitrile 25.0 Potassium oleate 2.0 Tert-dodecyl mercaptan 0.6 Cumene hydroperoxide 1.4 Ferrous sulfate solution (0.2%) 3.0 Formaldehyde-modified sodium sulfoxylate (10%) 3.0 Ethylenediaminetetraacetic acid solution (0.25%) 20.0 Distilled water 200.0.

<Production Example IV-3> Production of Rubbery Graft Copolymer (D3) Using the enlarged rubber emulsion (C) produced in Production Example III,
The graft polymerization reaction proceeds directly according to the following formulation, and a rubbery graft copolymer (D3) obtained by an emulsion polymerization method having a rubber content of 50% by weight is obtained. Ingredient Parts by Weight enlarged rubber latex (C) (solid content) 100.0 styrene 75.0 acrylonitrile 25.0 Oleic acid potassium 2.0 tert-dodecyl mercaptan 0.6 cumene hydroperoxide 1.4 ferrous sulfate solution (0.2%) 8.6 Formaldehyde sodium sulfoxylate (10% ) 8.6 Ethylenediaminetetraacetic acid solution (0.25%) 57.0 Distilled water 200.0.

<Production Example IV-4> Production of Rubbery Graft Copolymer (D4) A graft polymerization reaction is carried out according to Production Example IV-1, and the formulation of the graft polymerization reaction in this example is as follows. is there. Ingredient Parts by Weight enlarged rubber latex (C) (solid content) 100.0 styrene 22.0 acrylonitrile 8.3 methyl methacrylate 3.0 oleate potassium 1.2 tert-dodecyl mercaptan 0.2 cumene hydroperoxide 0.5 ferrous sulfate solution (0.2%) 3.0 Formaldehyde reduction sulphoxylate Sodium (10%) 3.0 Ethylenediaminetetraacetic acid solution (0.25%) 20.0 Distilled water 200.0 The rubber graft emulsion obtained by the above formulation is coagulated with calcium chloride, dehydrated, and dried until the water content becomes 2% or less. , The obtained rubbery graft copolymer of the emulsion polymerization method (D
The rubber content of 4) is 75%.

<Production Example IV-5> Production of Rubbery Graft Copolymer (D5) The graft polymerization reaction is carried out according to Production Example IV-1, and the formulation of the graft polymerization reaction in this example is as follows. is there. Ingredients by weight Component enlarged rubber emulsion (C) (solid content) 100.0 styrene 22.5 acrylonitrile 7.8 α-methylstyrene 1.0 N-phenylmaleimide 2.0 potassium oleate 12.0 tert-dodecylmercaptan 0.2 cumene hydroperoxide 0.5 ferrous sulfate solution (0.2% 2.0) Formaldehyde-modified sodium sulfoxylate (10%) 3.0 Ethylenediaminetetraacetic acid solution (0.25%) 20.0 Distilled water 200.0 The rubber-like graft emulsion produced by the above formulation is coagulated with calcium chloride, and after dehydration, the water content is reduced to 2% or less. The rubber content of the rubbery graft copolymer (D5) obtained by the emulsion polymerization method is 75% by weight.

<Production Example V-1> Production of Rubbery Graft Copolymer (E1) Using 0.1 part by weight of benzoyl peroxide as an initiator,
Parts by weight of butadiene (product of Asahi Kasei Corporation, trade name is Asaden
o 55AS) is completely dissolved in 74.4 parts by weight of styrene, 25.6 parts by weight of acrylonitrile and 30 parts by weight of ethylbenzene to form a starting solution. Thereafter, the raw material solution was continuously fed into the first reactor having a volume of 45 liters, and the reaction temperature was increased to 100.
° C, a cooling circulation pipe is provided in the reactor, and a screw stirrer is provided. The stirring speed was 150 rpm, the monomer conversion rate in the first reactor was 15%, the mixture after the reaction was taken out in the first reactor, and the mixture was successively fed to the second, third, and fourth reactors. Feeding and adding 0.1 parts by weight of tert-dodecyl mercaptan into the third reactor, phase inversion occurs in the second reactor. The apparatus of the second, third and fourth reactors described above is the same as the first reactor except that the reaction temperature is 105
° C, 110 ° C, 125 ° C, stirring speed is 270rpm, 150r
The order is pm and 110 rpm. 60% conversion of the mixture
When the mixture becomes, the mixture is taken out and sent to a devolatilizer to remove unreacted monomers and volatile substances, and then extruded and sized to obtain a rubber-like graft copolymer by bulk (or solution) polymerization. A combination (E1) is obtained. The particle size distribution of the rubber particles is 0.65 to 1.0 μm, the rubber content is 10% by weight, and the styrene and acrylonitrile contents are 70% by weight and 30% by weight, respectively.

<Production Example V-2> Production of Rubbery Graft Copolymer (E2) According to the production method of Production Example V-1, except that benzoyl peroxide as an initiator was 0.15% by weight and the first reaction was carried out. The monomer conversion of the vessel is 16%, the rotation speed is 200 rpm, the temperature of the second reactor is 110 ° C., and the stirring speed is 300 rpm. After the reaction, it is extruded, granulated, and subjected to a bulk (or solution) polymerization rubbery graft copolymer (E
2) can be manufactured. The particle size distribution of the rubber particles is 0.45 to 0.72 μm, the rubber content is 10% by weight, the content of styrene and acrylonitrile is 72% by weight,
28% by weight.

<Method for Measuring Physical Properties> Standards for measuring the physical properties of the resin compositions prepared in Examples and Comparative Examples of the present invention are as follows.

1. Falling ball impact strength (unpainted) A test piece with a radius of 50 mm and a thickness of 3 mm is made by an injection molding machine and measured by the ASTM D-3763 method.

2. Low temperature falling ball impact strength (painted product) A disk test piece with a radius of 50 mm and a thickness of 3 mm is made by an injection molding machine, and a PU paint made by Taiwan Taiying Corporation: hardener: diluent = 100: 10: 50. Mix and paint with a spray. After the coated product has been dried at 70 ° C for 20 minutes,
℃ ℃ freezer for 4 hours, take out, and finally ASTM
Measured by the D-3763 method.

3. Surface glossiness 50mm (width) x 90m at 280 ° C molding temperature by injection molding machine
Make a test piece of m (length) x 3 mm (thickness). The test pieces were measured at an incident angle of 60 ° using a gloss meter, and the average value of five sets of test pieces was measured. The unit is%.

4. Tensile strength Measured by the ASTM D-638 method, and the unit is kg / cm ² .

<Example 1> As shown in Table 1, the rubbery graft copolymer and the styrene-acrylonitrile copolymer (composition weight ratio of acrylonitrile / styrene = 30)
/ 70. The weight average molecular weight is 120,000. ) Is adjusted to make the total rubber amount of the resin mixture after mixing 19% by weight. And for 100 parts by weight of the resin composition,
2,6-di-tert-butyl-4-methylphenol 0.1
Parts by weight, tris (nonylphenyl) phosphite 0.1
Parts by weight and 2.0 parts by weight of ethylenebisstearylamide are added and mixed, and extruded at 240 ° C. using a Werner & Pfleiders ZSK-35 twin screw extruder in Germany to granulate. Then 2
At 20 ° C, test specimens were prepared using a series No. SM-90 injection molding machine manufactured by Taiwan Seisho Corporation, and the ball impact strength when unpainted, the cold ball impact strength at low temperature, the surface glossiness and the tensile strength were measured. Table 4 shows the measurement results. Table 1
Table 1 also shows the fraction of rubber particles, the average distance between rubber particles, and the dispersion coefficient.

<Examples 2 to 13> In the same manner as in Example 1, resin compositions were prepared at the ratios of various polymers shown in Tables 1 and 2, and physical properties were measured in the same manner as in Example 1. . Tables 4 and 5 show the measurement results.

<Comparative Examples 1 to 13> In the same manner as in Example 1, resin compositions were prepared at the ratios of various polymers shown in Tables 2 and 3, and physical properties were measured in the same manner as in Example 1. . Tables 5 and 6 show the measurement results.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

[Table 5]

[0077]

[Table 6]

As is clear from the test results of the comparative examples in Tables 5 and 6, when the fraction of the number of rubber particles having a specific particle size is out of the range of the present invention or the dispersion coefficient is 53 to 65. When the value is out of the range, the molded article has a poor low-temperature falling ball impact strength and a low equilibrium in tensile strength and surface glossiness of the resin. As can be seen from the test results of Examples in Tables 4 and 5, the rubber-modified styrenic resin composition of the present invention has a rubber particle size distribution (different particle size distribution) and a distance between average rubber particles. By proper adjustment, it has the characteristic that excellent falling ball impact strength, high tensile strength, good gloss and falling ball impact strength at low temperature, especially good low temperature impact strength after molding coating can be maintained. A composition is obtained. Apply for a patent for this invention in accordance with the law, not only because its composition is new, but also of industrial value. The scope of the present invention includes not only the above-described embodiments but also all modifications or changes made by those skilled in the art within the essential scope of the present invention.

Claims (1)

[Claims] 1. An acrylonitrile monomer and / or a (meth) acrylate monomer 10 to 50% by weight, a styrene monomer 50 to 90% by weight, and other copolymers added as required. Polymerizable unsaturated vinyl monomer 0-40
In a resin composition containing a matrix of a styrene-acrylic copolymer obtained by copolymerizing a monomer mixture containing 1% by weight and butadiene rubber particles dispersed in the matrix, the particle size of the rubber particles And a rubber-modified styrenic resin composition having a dispersion coefficient satisfying the following formula. D. P = 4 × (1 / L) + 10A + 50B + 50C [where D. P is the dispersion coefficient, the value of which is in the range of 53 to 65, A is the fraction of rubber particles having a particle diameter of 0.12 μm or less in the whole rubber particles, the value is between 0.1 to 0.85, and B is The fraction of rubber particles having a particle diameter of more than 0.12 μm and less than 0.5 μm occupies the entire rubber particles, and the value is between 0.05 and 0.85. C is the fraction that rubber particles having a particle diameter of 0.5 μm or more occupy the entire rubber particles. Where the value is between 0.01 and 0.2, and L is the distance (μm) between the average rubber particles. ]