CN1121938A - Styrenic resin composition with high gloss, impact resistance and good processing fluidity - Google Patents

Abstract

The invention discloses a styrene-based resin composition with impact resistance, high gloss and good processing fluidity, which comprises: (I) 40-90wt% styrene-based copolymer (A), (II) 10 - 60 wt% rubbery graft copolymer (B), this rubbery graft copolymer (B) also includes: 65-95 wt% rubber (B ₁ ) and 5-30 wt% styrenic copolymer (B ₂ ), Wherein in the styrenic copolymer (B ₂ ), the ungrafted styrenic copolymer content accounts for below 20wt% of the styrenic copolymer (B ₂ ) total amount, and the molecular weight of the grafted styrenic copolymer is 20,000-150,000.

Description

Styrenic resin composition with high gloss, impact resistance and good processing fluidity

The present invention relates to a styrenic resin composition with high gloss, impact resistance and good processability.

Those skilled in the art understand that the styrenic resin composition is an impact-resistant resin composition prepared by dispersing a rubber-like graft copolymer in a styrenic copolymer. In terms of application, the resin materials used in the casings of home appliances and automotive molded products need to have both impact resistance and high gloss, and ABS resin is a representative styrene-based resin composition material that meets the above requirements. Therefore, , has been widely adopted for many years.

However, generally, the higher the impact resistance of the resin, the lower its gloss; on the contrary, the higher the gloss of the resin, the poorer its impact resistance; Rubber content or rubber particle size is related. According to previous studies, the more rubber content in the resin or the larger the rubber particle size, the stronger the impact resistance; and the lower the rubber content in the resin or the smaller the rubber particle size, the higher the glossiness . Therefore, how to prepare a resin material with both high gloss and excellent impact strength has become a long-standing subject in this technical field that needs to be researched and broken through.

In order to make the resin have both impact resistance and high gloss, one of the traditional improvement methods is to make the resin composition contain two or more rubber-like copolymers with different rubber particle sizes, such as Japanese Patent Application No. 59-202211 that is. Alternatively, it is also possible to achieve the purpose by limiting the gel content of the rubbery copolymer in the resin composition, as disclosed in Japanese Patent Application Laid-Open No. 62-84109. However, because the above-mentioned improvement methods all need to use rubber-like copolymers containing large particle sizes, the improvement effect on gloss is still very limited. In addition, Japanese Patent Laid-Open No. 62-201959 mentioned that the composition contains a rubber-like copolymer with a rubber particle size of 0.04-0.15 μm, which can produce a resin with high gloss and impact resistance. However, its impact resistance has not reached a practical level.

In order to strengthen the physical properties of the resin, another traditional improvement method is to graft the hard phase of the styrene-based copolymer on the rubber. In this way, to achieve the best physical properties, such as: high impact strength, high gloss The physical properties such as high density and other physical properties need to be achieved by making the graft level of the rubber graft copolymer high to a certain extent, otherwise good impact strength and high gloss cannot be obtained. But, in order to make the required reactor capacity or quantity of the rubber graft copolymer of aforementioned high degree of grafting all bigger, therefore, can't obtain high-efficiency production, also can cause shortcomings such as high production cost and uneconomical ; and when using emulsion polymerization to prepare rubber graft copolymers, due to the high degree of grafting, more waste water will be produced, which will have a bad impact on the environment. Therefore, how to achieve high production efficiency, low cost and low pollution Under such circumstances, the preparation of rubber graft copolymers with a low degree of grafting and the styrene-based resin materials with high gloss and excellent impact resistance have become a subject that has long been awaiting research breakthroughs.

The main purpose of the present invention is to provide a styrenic resin composition with impact resistance, high gloss and good processing fluidity under the condition of high efficiency, low cost and low pollution.

The feature of the present invention is that this impact-resistant polystyrene resin composition with high gloss and good processing fluidity mainly includes: (I) 40-90wt% styrene copolymer (A), the styrene The copolymer (A) is composed of 50-90wt% vinyl aromatic monomer, 10-50wt% unsaturated nitrile monomer and/or methacrylate monomer and 0-40wt% other copolymerizable monomer Composition; (II) 10-60wt% rubbery graft copolymer (B), this rubbery graft copolymer (B) comprises: 65-95wt% rubber (B ₁ ) and 5-30wt% styrene-based copolymer (B ₂ ) (including those grafted and not grafted on rubber), wherein the styrene copolymer (B ₂ ) is composed of 50-90 wt% vinyl aromatic monomer, 10-50 wt% unsaturated nitrile monomer and/or methacrylate monomers and 0-40wt% other copolymerizable monomers, and the content of ungrafted styrenic copolymer accounts for 20wt% of the total amount of styrenic copolymer (B ₂ ) Below, and the molecular weight of the grafted styrenic copolymer is 20,000-150,000.

According to the above composition, a styrenic resin composition having both impact resistance and high gloss can be obtained.

The styrene copolymer (A) in the styrene resin composition of the present invention is composed of 50-90wt% vinyl aromatic monomer, 10-50wt% unsaturated nitrile monomer and/or methacrylate monomer body and 0-40wt% of other copolymerizable monomers; wherein,

Vinyl aromatic monomers can be: styrene, α-methylstyrene, α-chlorostyrene, p-tert-butylstyrene, p-methylstyrene, o-chlorostyrene, p-chlorobenzene Ethylene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, 2,4,6-tribromostyrene and 2,5-dibromostyrene, etc., among which, styrene or α-methanol is preferred base styrene.

Unsaturated nitrile monomer can be: acrylonitrile, α-methacrylonitrile, methacrylonitrile, fumacronitrile etc., wherein, preferred acrylonitrile; Methacrylate monomer can be: methyl methacrylate, Ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, 2— Hydroxyethyl ester, glycidyl methacrylate, dimethylaminoethyl methacrylate, etc., among them, methyl methacrylate is preferable.

Suitable copolymerizable monomers include maleimide monomers such as: maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide Toimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide Laimide, N-2, 3- or 4-tolyl maleimide, N-2, 3- or 4-ethylphenyl maleimide, N-2, 3- or 4-butyl Phenylmaleimide, N-2,6-tolylmaleimide, N-2,3-or 4-chlorophenylmaleimide, N-2,3-or 4-bromo Phenylmaleimide.

Other copolymerizable monomers include: acrylic monomers, anhydrous maleic acid, anhydrous methethylenesuccinic acid, anhydrous methylmaleic acid, anhydrous pentapentacic acid, ethylene, propylene, 1 -butene, 1-pentene, 4-methyl-1-pentene, ethylene chloride, ethylene tetrafluoride, ethylene chlorotrifluoride, propylene hexafluoride, butadiene, propenylamine, isobutylene amine, vinyl acetate, vinyl ether, vinyl ketone, etc.

The rubber-like graft copolymer (B), which accounts for 10-60wt% of the total weight of the styrene-based resin composition of the present invention, contains rubber (B ₁ ) and styrene-based copolymer (B ₂ ); wherein,

Rubber (B ₁ ) content is 65-95wt%, and preferably 75-90wt%, they can be polybutadiene, butadiene interpolymer, ethylene-propylene copolymer [such as EPDM (ethylene-propylene-diene terpolymer) etc.] or acrylate-based polymers; the above-mentioned butadiene-based copolymers include butadiene/styrene copolymers, butadiene/acrylonitrile copolymers, etc.; the average particle size of the rubber is 0.05-0.6 μm, preferably 0.2- 0.5 μm, if a bimodal particle size distribution is adopted, the average particle size of the first group is 0.04-0.18 μm, and the average particle size of the second group is 0.20-0.6 μm.

The aforementioned rubber (B ₁ ) can be prepared by emulsification, solution or block polymerization, and the preferred method is: directly polymerize the monomer into a rubber emulsion of 0.05-0.6 μm by emulsion polymerization; or prepare the monomer by emulsion polymerization After forming a rubber emulsion with a small particle size of 0.05-0.20 μm, the above-mentioned small-particle rubber emulsion is grown into a rubber emulsion with a size of 0.22-0.6 μm by freezing hypertrophy method, mechanical hypertrophy method or additive hypertrophy method, so as to prepare for further graft copolymerization reaction . Wherein, the additives used in the additive hypertrophy method can be: acidic substances such as acetic anhydride, hydrogen chloride, sulfuric acid, or: basic substances such as sodium chloride, potassium chloride, calcium chloride, magnesium chloride, magnesium sulfate, and ( Meth)acrylic acid-(meth)acrylate copolymer (such as: methacrylic acid-butyl acrylate copolymer) and other acid group-containing polymer coagulants.

The styrene-based copolymer (B ₂ ) in the rubber-like graft copolymer (B) includes those grafted on the rubber and those not grafted on the rubber, and the styrene-based copolymer (B ₂ ) is composed of 50-90wt %vinyl aromatic monomer, 10-50wt% unsaturated nitrile monomer and/or methacrylate monomer and 0-40wt% other copolymerizable monomer; while not grafted on the rubber The content of the styrene-based copolymer accounts for less than 20 wt% of the total amount of the styrene-based copolymer (B ₂ ); and the molecular weight of the styrene-based copolymer grafted on the rubber is between 20,000-150,000, and preferably 40,000-120,000 .

As mentioned above, in the rubbery graft copolymer (B) of the present invention, the rubber (B ₁ ) accounts for 65-95 wt%, and preferably 75-90 wt%, and in the styrene-based copolymer (B ₂ ), there is no The content of the styrenic copolymer grafted on the rubber is less than 20wt% of the total amount of styrenic copolymer (B ₂ ), and at the same time, the molecular weight of the grafted styrenic copolymer is 20,000-150,000, and preferably 40,000- 120,000. When the rubber (B ₁ ) in the rubber-like graft copolymer (B) accounts for less than 65wt%, it is impossible to obtain a resin with high preparation efficiency, low cost and low pollution. And the processing fluidity becomes worse, and the impact resistance and elongation will also drop sharply, which cannot meet the practical requirements. In addition, under the condition that the rubber (B ₁ ) accounts for 65-95 wt%, when the content of the styrene-based copolymer not grafted on the rubber accounts for more than 20 wt% of the total amount of the styrene-based copolymer (B ₂ ), it is easy to cause The poor coagulation of rubber makes the dispersion between rubber particles not good, and cannot be uniformly dispersed in the hard phase of styrene-based copolymers, resulting in poor impact resistance, and no improvement in gloss, and poor rigidity. Impact. When the molecular weight of the styrene-based copolymer (B ₂ ) in the rubbery graft copolymer is less than 20,000, good impact strength and rigidity cannot be obtained. On the contrary, if the molecular weight of the styrene-based copolymer exceeds 150,000, the glossiness of the composition will decrease, and the processing fluidity will also deteriorate.

The styrenic copolymer (A) of the styrenic resin composition of the present invention can be prepared according to any conventional polymerization method, such as suspension polymerization, block suspension polymerization or block polymerization.

The rubbery graft copolymer (B) of the styrene-based resin composition of the present invention can be prepared by known methods, such as block polymerization, suspension polymerization, block-suspension polymerization, solution polymerization or emulsion polymerization, etc., wherein , preferably emulsion polymerization. In the preparation process of the graft copolymer, the styrene-based copolymer (B ₂ ) can be directly formed in the reaction, and the styrene-based copolymer can be grafted on the rubber (B ₁ ), or it can be ungrafted in a free state. exist.

The polymerization initiator of the present invention can use the initiator commonly used in traditional technology, for example dibenzoyl peroxide (benzoyl peroxide), diisopropyl benzene (diiso-propyl benzene hydroperoxide), hydrogen peroxide isopropyl benzene Propylbenzene (cumene hy-droperoxide), tert-butyl hydroperoxide (tert-butyl hydroperoxide), potassium persulfate (potassium persulfate), etc., among them, organic hydroperoxides are preferred.

The present invention can also use traditional technical activators such as the activator of redox catalytic system or iron ion, for example: sodium pyrophosphate dextrose (sodium pyrophosphate-dextrose), sodium formaldehyde sulfoxylate (sodium formaldehyde sulfoxylate), ascorbic acid ( Ascorbic acid), dihydroxy acetone (dihydroxy acetone), etc. can be used; in addition, ethylene diamine tetraacetic acid salt (ethylene diamine tetraacetic acid salt) can also be added to promote its effect; the source of iron ions can use ferric chloride or sulfurous acid iron.

The content of styrenic copolymer not grafted on the rubber can be controlled by polymerization conditions, such as: polymerization temperature, initiator, emulsifier, type and amount of chain transfer agent, addition method of monomer, etc. to be controlled.

In addition, chain transfer agents can also be added according to traditional techniques to adjust the molecular weight of the graft polymer, such as: n-butyl mercaptan, n-octyl mercaptan, n-dodecane Base mercaptan (n-dodecylmercaptan), tert-dodecyl mercaptan (tert-dodecyl mercaptan).

The molecular weight of the graft polymer of the present invention can also be adjusted by changing polymerization conditions such as polymerization temperature, type and amount of initiator, and addition method of monomers.

The suitable reaction temperature of the present invention is below 90°C, preferably 30-80°C.

The styrene-based resin composition of the present invention may add other substances as needed, and examples of such substances include: antioxidants, lubricants, ultraviolet absorbers, ultraviolet stabilizers, antistatic agents, fillers, reinforcing agents, coloring agents, etc. agent, flame retardant, flame retardant aid, heat stabilizer, coupling agent or other additives, etc., the above additives can be added incidentally during the polymerization reaction, after the polymerization reaction or before solidification and during extrusion mixing.

Antioxidants usually use substances such as phenolic antioxidants, thioether antioxidants, phosphorus antioxidants, chelating agents; representative phenolic antioxidants are: octadecyl (3,5-bis-tert-butyl- 4-hydroxyphenyl) propionate, triethylene glycol bis [3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentalysitol tetrakis [3-(3 , 5-bis-tert-butyl-4-hydroxyphenyl) propionate], 2-tert-butyl-6-(3-tert-butyl-2-hydroxyl-6-methylbenzyl)-4-methyl phenyl acrylate, 2,2'-methylenebis(4-methyl-6-tert-butylphenol) and 2,2'-thiobis(4-methyl-6-tert-butylphenol), etc. .

Representative thioether antioxidants are: distearoyl thiodipropionate, dipalmitoyl thiodipropionate, pentaerythritol-tetra-(β-dodecyl-thiopropionate) , Dioctadecyl sulfide, etc.

Phosphorus antioxidants are phosphite antioxidants, representative ones are: tris(nonylphenyl) phosphite, dodecyl phosphite, cyclic neopentane tetrahydronaphthyl bis(octadecyl) Alkyl phosphite), 4,4'-butylene bis(3-methyl-6-tert-butylphenyl-ditridecyl phosphite), tri(2,4-tert-butylphenyl ) phosphite, or tetrakis(2,4-tert-butylphenyl)-4,4'-extended biphenyl phosphate, oxidized 9,4-dihydro-9-oxo-10-phenanthrene phosphate, etc.

Representative chelating agents include: dibenzoylmethane, sodium salt of diethylamine tetraacetic acid, etc.

The added amount of the above-mentioned antioxidant is generally 0.03-1.6 wt% in total with respect to the total styrenic resin.

Representative lubricants include: sodium stearate, magnesium stearate, lithium stearate and other metal soaps, ethylene distearamide, methylene distearamide, palmitic acid amide, butyl stearate , palmityl stearate, polypropionyl tristearate, n-docosanoic acid, compounds such as stearic acid, polyethylene wax, octacosanoic acid wax, carnauba wax, petroleum wax etc.; the amount of lubricant added is generally 0.03-5.0 wt% in total with respect to the total styrenic resin. Representative UV absorbers include: benzotriazole-based compounds, benzophenone-based compounds, and representative UV stabilizers include: retarded amine-based compounds; the amount of the aforementioned substances added relative to the total styrene-based resin Usually it amounts to 0.02-2.0 wt%.

Representative antistatic agents include: tertiary amine compounds, quaternary ammonium compounds and other low-molecular compounds or polyamide polyethers, such as 3-chloro-1,2-propylene oxide polymers with permanent anti-static properties. Sexual polymeric substances.

Representative fillers are: calcium carbonate, silica, mica.

Representative reinforcing agents include: glass fiber, carbon fiber, and various whiskers.

Representative coloring agents are: titanium oxide, iron oxide, graphite, phthalocyanine dyes.

Representative flame retardants or flame retardant additives are: decabromodiphenyl ether, tetrabromobisphenol A, brominated polystyrene oligomer, brominated epoxy resin, hexabromocyclododecane, chlorine Chemicalized polyethylene, triphenyl phosphate, red phosphorus, antimony oxide, antimony hydroxide, magnesium hydroxide, zinc borate, melamine, silicone oil, polytetrafluoroethylene powder, expandable graphite, etc.

Representative stabilizers include: dibutyltin maleate, basic magnesium aluminum hydroxycarbonate, etc. Representative coupling agents include: silane-based, titanate, germanate-based compounds.

In the styrenic resin composition of the present invention, for modification, polymerization system additives can be appropriately used. Examples of the above-mentioned representative polymerization system additives include various propylene-based polymers for improving extrusion molding processability (referred to as a processing aid), vinyl chloride resin, polymethyl methacrylate, polycarbonate resin, polyamide resin, polybutylene p-ferrate, olefin-based polymer, styrene-based plastic elastomer, Low molecular weight styrene-maleic anhydride copolymer, silicone oil, various compatibilizers, etc.

The ratio of the styrene-based copolymer (B ₂ ) in the rubber-like graft copolymer (B) not grafted on the rubber is determined by the following method: 1 g of a sample of the rubber-like graft copolymer is dissolved. In 35g of acetone, after stirring for 2 hours, centrifuge at a high speed at 15000rpm for 1 hour, then filter the clarified liquid, dry the insoluble matter and weigh it, then the grafting rate can be obtained from the rubber content in the sample, and then The proportion of ungrafted styrenic copolymer was found from the graft ratio and the rubber content in the sample.

According to the research of Dinges et al. (refer to Die Makromol.Chemie101, 1967, p. 200-213), the molecular weight of the grafted copolymer is exactly the same as that of the ungrafted copolymer, so it is determined that the ungrafted styrene The molecular weight of the copolymer can indirectly obtain the molecular weight of the grafted styrenic copolymer. In the present invention, the measuring method of the molecular weight of the ungrafted styrenic copolymer is that the sample of 3g rubbery graft copolymer is dissolved in 100g acetone earlier, after stirring for 2 hours, then under the rotating speed of 15000rpm, high-speed Centrifuge for 1 hour, then analyze the molecular weight of the ungrafted styrene-based copolymer in the clarified liquid by GPC (gas permeation chromato-graph).

The styrenic resin composition that is made by embodiment and comparative example, its various physical property measuring methods are as follows: 1. melt index (MI, is the index of processing fluidity):

Tested according to ASTM-D1238G. ②Izod impact strength (Izod):

Measured according to ASTM-D256. ③tensile strength (tensile strength):

Measured according to the method of ASTM-D638. ④ Gloss:

Measured according to the method of ASTM-D523.

In the following examples and comparative examples, all parts and percentages (%) are by weight unless otherwise specified. Example 1

Into the stirred reactor, add 250 parts of rubber emulsion (composition: polybutadiene solid content 30%, gel content 75%, average particle diameter 0.26 μm). The reaction temperature was heated to 70°C. Add 3.0 parts of 0.2% ferrous sulfate solution, 0.9 parts of 10% sodium formaldehyde sulfoxylate solution and 3.0 parts of 0.25% ethylenediaminetetraacetic acid solution. The monomer solution and the starter solution were added dropwise on average in 6 hours. The monomer solution contained 18.75 parts of styrene, 6.25 parts of acrylonitrile, and 2.0 parts of t-dodecylmercaptan. The starter solution then contained 30 parts deionized water, 3.0 parts cumene hydroperoxide and 3.0 parts 10% sodium lauryl sulfate solution. After the monomer solution and the starter solution are dropped, continue to keep warm and stir for 2 hours to obtain a rubbery graft copolymer [ie component (B)].

Add octadecyl-3-(3,5-di-tert-butyl-4-hydroxyl-phenyl)-propionate (Ciba Geigy Production, trade name IRGANOX 1076) 0.5 part, 1.0 part of di-stearyl thio-di-propionate (di-stearyl thio-di-propionate), after mixing for 20 minutes, add 2% calcium chloride solution, It was allowed to coagulate at 85°C, filtered, dehydrated, and then vacuum-dried at 60°C.

Dried rubber-like graft copolymer powder, its ungrafted styrenic copolymer (AS) accounts for 9% of the styrenic copolymer (B ₂ ) total amount, the molecular weight of the grafted styrenic copolymer to 56,000.

The rubbery graft copolymer powder after drying is mixed with AS resin [being component (A)] again, (its monomer weight ratio is: acrylonitrile/styrene=30/70, molecular weight is 120,000), makes A styrene-based resin composition with a rubber content of 17% of the total weight of the composition; add 3.0 parts of a lubricant and a stabilizer, and extrude, mix and granulate at 200° C., then injection mold, and measure its physical properties. Example 2

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 1.6 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: In 2.4 parts of gained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 12%

(2) The molecular weight of the grafted styrene-based copolymer: 63,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Example 3

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 283.3 parts of 0.2% ferrous sulfate solution: 1.8 parts of 10% sodium formaldehyde sulfoxylate solution: 0.5 part of 0.25% ethylenediaminetetraacetic acid Solution: 1.8 parts monomer solution:

Styrene: 11 parts

Acrylonitrile: 4 parts

Tertiary - dodecyl mercaptan: 1.2 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 1.8 parts

10% sodium lauryl sulfate solution: In 1.8 parts of gained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 10%

(2) The molecular weight of the grafted styrene-based copolymer: 61,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Example 4

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 4.5 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: 5 parts

In addition, when preparing the rubber-like graft copolymer [component (B)], the reaction temperature was 80°C, and the monomer solution and the initiator solution were equally dropped into the stirred reactor over 5 hours. In the obtained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 10%

(2) The molecular weight of the grafted styrene-based copolymer: 36,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Example 5

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 1.2 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: 1 part

In addition, when preparing the rubber-like graft copolymer [component (B)], the reaction temperature was 60°C, and the monomer solution and the initiator solution were equally dropped into the stirred reactor over 8 hours. In the obtained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 10%

(2) The molecular weight of the grafted styrene-based copolymer: 112,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Example 6

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 3 parts

Methyl methacrylate: 3 parts

Tertiary - dodecyl mercaptan: 1.6 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: In 2.4 parts of gained rubbery graft copolymer [component (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 12%

(2) Molecular weight of grafted styrenic copolymer: 73,000, monomer weight ratio in AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Example 7

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 1.6 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: In 2.4 parts of gained rubbery graft copolymer [component (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 12%

(2) The molecular weight of the grafted styrene-based copolymer: 63,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene/N-phenylmaleimide=29.1/67.9/3.0, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Comparative Example 1

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 1.6 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: 5 parts

In addition, when preparing the rubber-like graft copolymer component (B), the reaction temperature was 55° C., and the monomer solution and the initiator solution were evenly dropped into the stirring reactor every 3 hours. In the obtained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 33%

(2) The molecular weight of the grafted styrene-based copolymer: 56,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Comparative Example 2

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 266.7 parts of 0.2% ferrous sulfate solution: 2.4 parts of 10% sodium formaldehyde sulfoxylate solution: 0.7 part of 0.25% ethylenediaminetetraacetic acid Solution: 2.4 parts monomer solution:

Styrene: 14 parts

Acrylonitrile: 6 parts

Tertiary - dodecyl mercaptan: 0.2 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 2.4 parts

10% sodium lauryl sulfate solution: 2.4 parts

In addition, when preparing the rubber-like graft copolymer component (B), the reaction temperature was 60° C., and the monomer solution and the initiator solution were evenly dropped into the stirring reactor every 6 hours. In the obtained rubbery graft copolymer [ingredient (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 10%

(2) The molecular weight of the grafted styrene-based copolymer: 19,5000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the obtained styrenic resin composition: 17% Comparative Example 3

Repeat the process described in Example 1, but use the following formula: rubber emulsion (ingredients as described above): 320 parts of 0.2% ferrous sulfate solution: 0.6 part of 10% sodium formaldehyde sulfoxylate solution: 0.2 part of 0.25% ethylenediaminetetraacetic acid Solution: 0.6 parts monomer solution:

Styrene: 3 parts

Acrylonitrile: 1 part

Tertiary - dodecyl mercaptan: 0.4 parts of starter solution:

Deionized water: 30 parts

Cumyl hydroperoxide: 0.6 parts

10% sodium lauryl sulfate solution: In 0.6 part of gained rubbery graft copolymer [component (B)] powder:

(1) Ungrafted styrenic copolymer (AS) accounts for the percentage of styrenic copolymer (B ₂ ) total amount: 9%

(2) The molecular weight of the grafted styrene-based copolymer: 58,000, the monomer weight ratio in the AS resin [component (A)] used:

Acrylonitrile/styrene=30/70, molecular weight 120000

(3) Rubber content in the resulting styrene-based resin composition: 17%

Table 1 has listed the composition of the styrenic copolymer [ingredient (A)] and the rubbery graft copolymer [ingredient (B)] used in the styrene resin composition that above-mentioned all examples and comparative example make , the overall composition of the obtained styrenic resin composition and the physical properties of the styrenic resin composition obtained in these Examples and Comparative Examples. In Table 1, the meanings represented by each symbol are as follows: AN: acrylonitrile SM: styrene monomer BD: polybutadiene MMA: methyl methacrylate gloss%: gloss (%) IZ: Izod resistance Impact strength (kg-cm/cm) MI: melt index (g/10min) TSy: yield point tensile strength (kg/cm ² ) EL: elongation (%)

The styrene-based resin composition according to the present invention can indeed have high gloss, impact resistance and good processing fluidity at the same time, so it is very suitable for processing and molding into shells of home appliances and automotive moldings, etc., which must have impact resistance at the same time and high gloss products. To sum up, the present invention breaks through the limitation that traditional styrene-based resins cannot have both impact strength and high gloss at the same time when the degree of grafting is low, so it is indeed a progressive, practical and novel invention.

Table 1 Example comparative example 1 2 3 4 5 6 7 1 2 3 Rubbery graft copolymer (B) Contentwt% 22.67 21.25 20 21.25 21.25 21.25 21.25 21.25 21.25 21.25 composition AN% 6.25 6 4 6 6 3 6 6 6 1 SM% 18.75 14 11 14 14 14 14 14 14 3 BD% 75 80 85 80 80 80 80 80 80 96 MMA% — — — — — 3 — — — — physical properties Gloss% 96 94 94 96 93 96 95 89 87 80 IZ 25.2 25.0 22.9 21.2 24.7 22.0 22.3 18.2 17.5 9.5 MI 1.55 1.64 1.71 1.78 1.54 1.66 1.52 1.55 1.35 1.36 TSy 450 455 458 435 460 440 460 420 440 403 EL twenty two 25 26 16 twenty four 19 twenty one 16 19 7

Claims (3)

1. a styrenic resin composition, comprising: (1) 40-90wt% styrenic copolymer (A), this styrenic copolymer (A) is made of 50-90wt% vinyl aromatic monomer , 10-50wt% unsaturated nitrile monomer and/or methacrylate monomer and 0-40wt% other copolymerizable monomer; (II) 10-60wt% rubbery graft copolymer (B ), this rubber-like graft copolymer (B) includes: 65-95wt% rubber (B ₁ ) and 5-30wt% styrene-based copolymer (B ₂ ) (including those grafted and not grafted on the rubber) , wherein the styrene copolymer (B ₂ ) is composed of 50-90wt% vinyl aromatic monomer, 10-50wt% unsaturated nitrile monomer and/or methacrylate monomer and 0-40wt% other Composed of copolymerizable monomers, and the content of ungrafted styrenic copolymer accounts for less than 20wt% of the total amount of styrenic copolymer (B ₂ ), and the molecular weight of the grafted styrenic copolymer is 20,000- 150,000. 2. The styrenic resin composition according to claim 1, wherein the rubber (B ₁ ) content in the rubbery graft copolymer (B) is 75 to 90 wt%. 3. The styrenic resin composition according to claim 1, wherein in the styrenic copolymer ( _B2 ) contained in the rubbery graft copolymer, the molecular weight of the grafted styrenic copolymer is 40,000-120,000.