JP3414429B2 - Rubber-modified impact-resistant styrenic resin composition and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact-resistant styrenic resin composition excellent in both gloss and impact resistance and a method for producing the same.

[0002]

2. Description of the Related Art Polystyrene is widely used in various applications because it has excellent rigidity, transparency, luster and the like and has good moldability. However, this polystyrene has a major drawback of being inferior in impact resistance, and various unvulcanized rubbers are used as a toughening agent in order to improve this drawback. Among them, impact-resistant styrene-based resin compositions in which a styrene-based monomer is radically polymerized in the presence of unvulcanized rubber and a styrene-based polymer is graft-polymerized on a rubber-like polymer are industrially widely produced. As unvulcanized rubber used for this purpose, there are polybutadiene rubber and styrene-butadiene copolymer rubber, and in particular, polybutadiene rubber is widely used for imparting excellent impact resistance.

In recent years, applications of impact-resistant styrene resins have been
As it spreads to housings and other parts of household electric appliances, axle parts, office equipment parts, daily sundries, toys, etc., various superior characteristics are required.
Above all, there is a strong demand for impact-resistant styrenic resins having excellent impact resistance and excellent gloss. Generally, the impact resistance can be improved by increasing the content of the rubber-like polymer, but the styrene resin having the increased rubber-like polymer has an improved impact resistance but has a decreased gloss. To do. On the other hand, the gloss can be improved by reducing the content of the rubber-like polymer or by refining the particles of the rubber-like polymer dispersed in the resin, but the impact resistance is significantly lowered. .

[0004]

As described above, since impact resistance and luster are contradictory properties, the balance between the contradictory properties of excellent impact resistance and luster is improved to a satisfactory level. Although it was difficult to do so, the present invention aims to obtain an impact-resistant styrene-based resin composition that solves the above-mentioned problems and has an excellent balance of physical properties of impact resistance and gloss. To do.

[0005]

DISCLOSURE OF THE INVENTION In the present invention, as a result of detailed examination of obtaining an impact-resistant styrenic resin having an excellent balance of physical properties of impact resistance and gloss, it has not been examined as a toughening agent. By using the specific modified conjugated diene rubber, it became clear that the above-mentioned object was achieved, and the present invention was completed. That is,
The present invention has a polystyrene equivalent weight average molecular weight of 50,000 measured by gel permeation chromatography.
In the conjugated diene polymer in the range of
Impact-resistant styrene resin composition containing 2 to 25 wt% of a carboxyl group-containing conjugated diene rubber containing 0.015 to 2.0 wt% of a carboxyl group as a toughening agent, and measured by gel permeation chromatograph Weight average molecular weight in terms of polystyrene is 50,000 to 7
2 to 25% by weight of a carboxyl group-containing conjugated diene rubber containing 0.015 to 2.0% by weight of a carboxyl group in a conjugated diene polymer having a range of 0,000 and a styrene-based monomer or a styrene-based monomer Of a mixture of a copolymerizable monomer with a copolymerizable monomer and radical polymerization by a bulk polymerization method, a bulk suspension polymerization method or a solution polymerization method. Is provided.

It has been found that the impact-resistant styrenic resin of the present invention can obtain a resin having an excellent balance of physical properties of impact resistance and gloss for the first time by using a specific modified conjugated diene rubber as a toughening agent. It is characterized by Hereinafter, the present invention will be described in detail. The modified conjugated diene rubber used in the present invention contains 0.015 to 2.0% by weight of a carboxyl group in the conjugated diene polymer,
The polystyrene equivalent weight average molecular weight measured by gel permeation chromatography is 50,000 to 70.
The conjugated diene rubber having a carboxyl group in the conjugated diene polymer can be obtained by a conventionally known method.

For example, a conjugated diene polymer having an active lithium terminal obtained by polymerizing at least one conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as a polymerization initiator is present in the presence of a Lewis base. A conjugated diene rubber containing a carboxyl group at the polymer end can be obtained by reacting with carbon dioxide underneath and then treating the carboxylithium salt with an acid or the like. Further, a terminal carboxyl group-containing conjugated diene rubber can be similarly obtained by reacting a polymer having an active lithium terminal with an acid anhydride such as maleic anhydride and fumaric anhydride,
The preferred method of introducing the carboxyl group is by reacting a polymer having an active lithium terminal with carbon dioxide.

The organolithium compound includes a monoorganolithium compound or a polyfunctional organolithium compound,
Alternatively, it may be a mixture of a polyfunctional organolithium compound and a monoorganolithium compound. Examples of the monoorganolithium compound include n-propyllithium and iso-
There are propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, benzyllithium and the like, but preferably n-butyllithium and s.
ec-Butyl lithium or the like is used.

Examples of polyfunctional organolithium compounds include dilithiomethane, 1,4-dilithiobutane, and 1,6.
-Dilithiohexane, 1,4-dilithiocyclohexene, 1,4-dilithio-2-ethylcyclohexane,
1,3-dilithio-4-phenylbutane, 1,2-dilithio-1,2-diphenylethane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,1-dilithiodiphenylene, 1, 4-dilithiobenzene, 1,5
-Dilithionaphthalene, dilithiopolybutadiene, dilithioisoprene, dilithiodiisoprene, dilithiopolyisoprene, 2,2 ', 2 "-trilithio-p-terphenyl, 1,3,5-trilithiobenzene, 1, 3,5
-Trilithio-2,4,6-triethylbenzene and the like.

In addition to the above, an organolithium compound substantially containing a polyfunctional organolithium compound by reacting a monoorganolithium compound with another compound may be used. Among these examples, a typical catalyst is a reaction product of at least one monoorganolithium compound and a polyvinyl aromatic compound, and for example, a reaction product of a monoorganolithium compound and a polyvinyl aromatic compound. (JP-A-48-103690), a reaction product obtained by reacting a monoorganolithium compound with a conjugated diene or a monovinylaromatic compound and then reacting with a polyvinylaromatic compound, or a monoorganolithium compound, a conjugated diene. Alternatively, a reaction product obtained by simultaneously reacting a monovinyl aromatic compound and a polyvinyl aromatic compound (West German Patent 2,0
03, 384) and the like are used. Furthermore, a catalyst obtained by reacting a reaction product of a monoorganolithium compound and a monovinylaromatic compound with a polyvinylaromatic compound, and then further reacting the monovinylaromatic compound (Japanese Patent Publication No. 50-37078). It is valid.

The term "polyvinyl aromatic compound" as used herein means
Divinylbenzene, 1,2,4-trivinylbenzene,
1,3-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4
-Trivinylbiphenyl and the like, and particularly divinylbenzene is preferable, but divinylbenzene includes o-, m-,
There are p- isomers, which are virtually satisfied with commercially available divinylbenzene, which is a mixture of these isomers.
The monovinyl aromatic compound includes styrene, vinyltoluene, vinylethylbenzene, vinylxylene, vinylnaphthalene, etc., but styrene is particularly common.
As the hydrocarbon solvent used in these reactions, butane,
Aliphatic hydrocarbons such as pentane and hexane, aliphatic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene are used.

The conjugated diene monomer used in the present invention is 1,
3-butadiene, isoprene, 2,3-dimethyl-1,
3-butadiene, 1,3-pentadiene, 3-methyl-
1,3-pentadiene, 1,3-heptadiene, 1,3
-Conjugated dienes such as hexadiene. The reaction of a living polymer having an active lithium terminal with carbon dioxide is preferably carried out in the presence of a Lewis base in order to reduce a coupling reaction which is a side reaction, and examples of suitable Lewis base include tetrahydrofuran and the like. Ethers or polyamines such as N, N, N ', N'-tetramethylethylenediamine and the like, preferably N,
N, N ', N'-tetotimethylethylenediamine is used.

The weight% of the carboxyl groups bonded in the conjugated diene rubber can be freely changed by the molar ratio of Lewis base and active lithium. There is no particular limitation on the method of adding the Lewis base, for example, a method of adding the compound after completion of the polymerization of the conjugated diene monomer, or a method of adding the compound before the polymerization of the conjugated diene monomer. Another method is to add the compound during the polymerization of the conjugated diene monomer. Polymerization of the conjugated diene monomer in the presence of a large amount of Lewis base is not preferable from the viewpoint of controlling the microstructure of the conjugated diene rubber, and generally, after the polymerization of the conjugated diene monomer is completed, the compound is A method of adding is preferably used.

Regarding the method of adding carbon dioxide, for example, a method of adding the compound after completion of the polymerization of the conjugated diene monomer, or silicon tetrachloride, tin tetrachloride, methyltrichlorosilane, tetramethoxysilane, tetraethoxysilane. A method of adding a known polyfunctional coupling agent such as alkoxysilane, carbon tetrachloride, diethyl adipate, etc., and then adding the compound is generally used. The carbon dioxide used may be solid or gaseous, but normally 1 to 10 g of dry gaseous carbon dioxide is used.
Under a pressure of kg / cm ² (gauge pressure), 0.5 to 100 mol per 1 mol of the organolithium compound is supplied into the polymer solution for reaction.

The reaction temperature is in the range of 50 ° C. to 140 ° C., preferably 70 ° C. to 110 ° C. When the reaction temperature exceeds 140 ° C., the reaction rate is lowered and the amount of introduced carboxyl groups is remarkably reduced. However, if the temperature is lower than 50 ° C., the proportion of the side reaction product does not change at all, a special device for cooling the reaction tank is required, and the viscosity increases, which is disadvantageous in industrial practice. The weight% of the carboxyl groups bonded in the conjugated diene rubber is the amount of carbon dioxide added and / or
Alternatively, the amount of the polyfunctional coupling agent can be arbitrarily changed.

It is also possible to mix the other conjugated diene polymer with the carboxyl group-containing modified conjugated diene rubber to adjust the weight% of the carboxyl groups. Furthermore, it is also possible to introduce a carboxyl group into the side chain of the conjugated diene rubber, for example, reacting carbon dioxide under the conditions described above after alkali metallizing the conjugated diene rubber in a hydrocarbon solvent with an alkali metallizing agent. Then, by treating the carboxyalkali metal salt with an acid or the like, a conjugated diene rubber having a carboxyl group bonded to the side chain of the polymer can be obtained.

Examples of the alkali metallizing agent include a mixture of alkyl lithium such as n-butyl lithium, sec-butyl lithium, tert-butyl lithium and iso-propyl lithium with polyamine, sodium alcoholate or potassium alcoholate, and the like. Above all,
Mixtures of alkyllithium / N, N, N ', N'-tetramethylethylenediamine, tertiary lithium alcoholates of alkyllithium / potassium or sodium are preferably used. Examples of the potassium or sodium tertiary alcoholate include sodium or potassium tert-butyl alcoholate, sodium or potassium tert-alcohol.
Examples include amyl alcoholate, sodium or potassium isopropyl alcoholate, sodium or potassium hexyl alcoholate, and the like. As the hydrocarbon solvent used in these reactions, alicyclic hydrocarbons such as butane, pentane and hexane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene are used. .

The alkali metallization reaction is carried out at -50 to 150 ° C.
The temperature is preferably 0 to 100 ° C., and the weight% of the carboxyl group bonded to the side chain can be adjusted by the amount of the alkali metallizing agent used and the reaction conditions. The conjugated diene rubber is 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene, 1,3-. It is a polymer of conjugated dienes such as hexadiene. Preferred conjugated diene rubbers are polybutadiene rubber, polyisoprene rubber, butadiene-isoprene copolymer rubber and the like. It is also possible to obtain a carboxyl group-containing conjugated diene rubber by modifying the conjugated diene rubber with a peroxide and an unsaturated carboxylic acid or a thiol group-containing carboxylic acid, and further, the carboxyl group-containing conjugate obtained by the above method. The conjugated diene rubber may be mixed with the diene rubber and used.

In the conjugated diene rubber having a carboxyl group in the polymer obtained by the above method, the carboxyl group contained in the polymer is in the range of 0.015 to 2.0% by weight, Preferably 0.025 to 1.0% by weight
Is. When the content of the carboxyl group is less than 0.015% by weight, it is difficult to obtain the impact resistant styrene resin composition of the present invention having excellent impact resistance and gloss, and more than 2.0% by weight. Then, there is no significant difference in the effect of the present invention, which is not preferable from the viewpoint of manufacturing cost. The carboxyl group content in the modified conjugated diene rubber can be easily determined by a method such as an infrared spectrophotometer or titration.

The conjugated diene rubber in the present invention has some influence on the impact resistance of the resulting impact-resistant styrene resin composition due to its microstructure. For example, when polybutadiene is used as the conjugated diene rubber, Two
-Vinyl content is 10-80%, cis-1,4 content is
It is preferably in the range of 10 to 85%, but in particular,
The 2-vinyl content is preferably 10 to 40%, more preferably 10 to 25%, and a polybutadiene having a 1,2-vinyl content outside this range is used. The resin has poor impact resistance. There is no particular limitation on the method for adjusting the 1,2-vinyl content, and any conventionally known method can be used. For example, when polymerizing a conjugated diene rubber, dimethyl ether, diethyl ether, tetrahydrofuran (THF), etc. are added to the polymerization system. And the like; amines such as dimethylamine; thioethers such as dimethyl sulfide and diethyl sulfide.

Further, hexamethylphosphoramide (H
MPA) is added (Japanese Patent Publication No. 43-5904), tetramethylethylenediamine (TMEDA) is added (Japanese Patent Publication No. 42-17199), and diethylene glycol dimethyl ether is added. The 1,2-vinyl bond may be polymerized so as to be uniform in the molecular chain, or may be polymerized so as to gradually change along the molecular chain (Japanese Patent Publication No. 48-875). (U.S. Pat. No. 3,301,840), and further polymerized so as to be bound in blocks (US Pat.
You may. In order to polymerize 1,2-vinyl bonds uniformly in the molecular chain, the polymerization initiation temperature is usually 30 to 90.
℃, the method of polymerizing as low temperature as possible is adopted, and in order to polymerize the 1,2-vinyl bond so as to gradually change along the molecular chain, a method of carrying out the polymerization at an elevated temperature, That is, a method in which the polymerization initiation temperature is usually 30 to 80 ° C. and the polymerization termination temperature is 85 to 120 ° C. is adopted.

Polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography of a carboxyl group-containing conjugated diene rubber containing 0.015 to 2.0% by weight of a carboxyl group in the polymer used in the present invention. Is in the range of 50,000 to 700,000, preferably 100,000 to 400,000, and the ratio Mw / Mn of the weight average molecular weight and the number average molecular weight (Mn) is 1.1 to 3. A range of 0.0 is preferable. If the Mw of the conjugated diene rubber used is less than 50,000, the resulting styrenic resin will have poor impact strength and M
When w exceeds 700,000, it is difficult to obtain a resin having excellent gloss because the required small-diameter particles cannot be obtained.

The impact-resistant polystyrene-based resin composition of the present invention is a styrene-based resin composition containing 2 to 25% by weight of the above-mentioned modified conjugated diene rubber. The intended effect of improving impact resistance is insufficient. On the other hand, when the amount of use exceeds 25% by weight, the impact resistance is improved, but the characteristics of the original polystyrene resin, such as tensile strength and rigidity, and gloss This is unfavorable because it impairs the appearance. The method for obtaining the impact-resistant styrene-based resin composition of the present invention is not particularly limited as long as it is considered so that the requirements of the present invention can be satisfied, and a known method can be used. 2 to 25% by weight of the conjugated diene rubber of the invention and 98 to 75% by weight of a mixture of a styrene monomer or a monomer copolymerizable with the styrene monomer are subjected to a bulk polymerization method, a bulk-suspension polymerization method or Radical polymerization is performed by a solution polymerization method to produce an impact-resistant styrene resin.

Bulk polymerization, which is one of the preferred methods for obtaining the high impact polystyrene resin composition of the present invention, generally involves first dissolving the modified conjugated diene rubber of the present invention in styrene and optionally adding toluene. Diluent such as ethylben,
Liquid paraffin, mineral oil, internal lubricants such as organic polysiloxane, antioxidants, mercaptans and α-methylstyrene dimer, etc. are added.
In catalytic polymerization using a radical initiator as a catalyst, the polymerization of styrene is continued at a lower temperature than usual, for example, at a temperature of 60 to 180 ° C.

In the case of catalytic polymerization, 1,1 is used as an initiator.
-Bis (t-butylperoxy) cyclohexane, 1,
Peroxyketals such as 1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane; di-t
-Butyl peroxide, 2,5-dimethyl-2,5-
Dialkyl peroxides such as di (t-butylperoxy) hexane and dicumyl peroxide; diacyl peroxides such as benzoyl peroxide, m-toluoyl peroxide and lauroyl peroxide;
Peroxydicarbonates such as dimyristyl peroxydicarbonate and diisopropyl peroxydicarbonate; t-butyl peroxyisopropyl carbonate, t-butyl peroxyacetate, di-t-butyl diperoxy isophthalate, t-butyl percarbonate Peroxyesters such as oxybenzoate; Ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide; Hydroperoxides such as p-mentha hydroperoxide, t-butyl hydroperoxide and cumene hydroperoxide; Azobis Azo compounds such as isobutyronitrile and azobiscyclohexanecarbonitrile are used.

These may be used alone or in combination of two or more, and if necessary, chain transfer agents such as mercaptans, α-methylstyrene linear dimer,
Terpinolene or the like can be used. Further, in this bulk polymerization method, an organic polysiloxane as an internal lubricant, for example, polydimethylsiloxane may be added in an amount of 0.005 to 10 parts by weight based on 100 parts by weight of the polymer, if desired. After the completion of the polymerization, when the unreacted styrene is contained in the produced polymer, the styrene can be removed by a known method, for example, a method of removing under reduced pressure or an extruder designed for the purpose of removing volatile matter. desirable. During the bulk polymerization, stirring can be carried out if necessary, but it is desirable to stop or moderate the stirring after the conversion rate of styrene to the polymer, that is, the polymerization rate has advanced by 60% or more. Stirring may lower the strength of the obtained polymer, and if necessary, the polymerization is carried out in the presence of a small amount of a diluent such as toluene or ethylbenzene, and after completion of the polymerization, these diluents are removed by heating together with unreacted styrene. May be.

The bulk suspension polymerization method is also useful in the production of the impact-resistant styrene resin composition of the present invention. In this method, the first half of the polymerization is carried out by the bulk polymerization and the second half of the reaction is suspended. It is carried out by polymerization. That is, the styrene solution of the modified conjugated diene rubber of the present invention is subjected to heat polymerization or catalyst addition polymerization in the absence of a catalyst in the same manner as in the case of the above-mentioned bulk polymerization, and usually 50% or less of styrene, particularly preferably 10 to 4
Up to 0% is partially polymerized by the bulk polymerization method and then this partially polymerized mixture is dispersed in the aqueous medium with stirring in the presence of a suspension stabilizer or a combination of this and a surfactant. The second half of the reaction is completed by the suspension polymerization method. The produced polymer is washed, dried and, if necessary, pelletized or powdered before use.

In addition to the above-mentioned methods, useful impact-resistant polystyrene resin compositions can be obtained by the conventionally known methods which are improved and improved. Further, a part of styrene forming the impact-resistant styrene-based resin composition together with the modified conjugated diene rubber of the present invention may be replaced with a monomer capable of radical polymerization with styrene other than styrene. The body is used in a range of 50% by weight or less based on the total monomers containing styrene, and examples of the copolymerizable monomer other than styrene include α-methylstyrene, vinyltoluene, vinylethylbenzene, vinylxylene, Examples thereof include monovinyl aromatic hydrocarbons such as vinylnaphthalene, conjugated dienes such as butadiene and isoprene, acrylonitrile and methyl methacrylate, and these monomers may be used alone or in combination of two or more.

The gel content (toluene insoluble content) in the impact resistant styrene resin composition obtained as described above is preferably in the range of 10 to 40% by weight, and the gel content in the resin composition is Swelling index in toluene is 7 to 13
Further, the weight average molecular weight of the resin portion is preferably 100,000 to 400,000, and more preferably 150,000 to 300,000. Since the amount of the styrene oligomer remaining in the resin affects the heat resistance, it is usually preferably 1% by weight or less, and particularly 0.5% by weight or less when heat resistance is required.

The impact resistant styrenic resin composition of the present invention can be molded into a wide variety of practically useful products by a processing method such as injection molding, extrusion molding, and the like. Accordingly, various additives such as antioxidants, ultraviolet absorbers, flame retardants, lubricants, release agents, fillers, organic polysiloxanes, and other thermoplastic resins such as general-purpose polystyrene, methacrylic resin, polyphenylene ether, polycarbonate , Styrene / butadiene block copolymer resin, methyl methacrylate / styrene copolymer resin, maleic anhydride / styrene copolymer resin, polyamide resin, polyester resin, etc.

[0031]

[Micro structure]

Using an infrared spectrophotometer, the Morello method (La chimi)
ca EL'industria 41 , 758 (19
58)]]. [Weight Average Molecular Weight] Using a gel permeation chromatograph (hereinafter referred to as GPC) manufactured by Waters, a column manufactured by DuPont was used, and a GPC curve measured at 35 ° C.
It was calculated as a polystyrene-converted weight average molecular weight.

[Content of Carboxyl Group in Polymer] The polymer is washed with a large amount of water to remove hydrogen chloride and catalyst residues, and then a 1/20 normal standard alcohol solution of potassium hydroxide is used to remove the medium. It was determined by performing a Japanese titration. [Izod Impact Strength] The obtained composition was compression-molded to prepare a test piece having a thickness of 3.2 mm, which was measured according to JIS-K-7110. [Gloss] Using a dumbbell test piece injection-molded according to ASTM D-638, the glossiness (incident angle 60 °) of the gate portion and the end gate portion was measured and averaged according to ASTM D-523. [Rubber particle size] It was measured using a Coulter counter method and expressed as a 50% median size.

(Examples 1 to 12 and Comparative Examples 1 to 4) Carboxyl group-containing polybutadiene rubbers were obtained by the methods shown below with the amounts and conditions shown in Table 1. Inner volume 1
A 0 liter stirrer and a jacketed autoclave were washed and dried, replaced with nitrogen, and then purified and dried in advance.
Add 3-butadiene and cyclohexane, then 1,2
-Tetrahydrofuran (THF) was added as a vinyl modifier, and an organic lithium catalyst was further added to start polymerization at 70 ° C. The polymerization temperature rose to about 100 ° C. Then, in some cases, silicon tetrachloride was added to obtain a living polybutadiene solution.

Next, N, N, N ', N'-tetramethylethylenediamine (TMEDA) was added to the living polybutadiene solution, and then 5 kg of dried carbon dioxide was added.
/ Cm ² (gauge pressure) It was introduced into the autoclave, and the temperature at this time was about 80 ° C. Further, 0.3 g of anhydrous hydrochloric acid was added and reacted for 30 minutes, and then the rubber solution was added to 18
It was extracted into a liter metal container, 10 liters of water was added, and the mixture was stirred for 60 minutes, then water was extracted and this operation was repeated 3 times to remove excess hydrochloric acid.

To the polymer solution thus obtained, 0.5 part by weight of 2,6-di-tert-butyl-4-methylphenol (BHT) was added as a stabilizer per 100 parts by weight of the polymer, and the solvent was removed by heating. A carboxyl group-containing polybutadiene rubber was obtained, and the charging amount and conditions at that time were as shown in Table 1. Regarding the organolithium catalyst used in the production of this polybutadiene rubber, the catalyst A is n
A 5 wt% n-hexane solution of butyllithium,
Catalyst B is a mixture of 1,2-dilithio-1,2-diphenylethane and n-butyllithium, and is an organolithium catalyst having a lithium atom ratio of 1: 4 based on the lithium atom in each compound. Yes, it was used as a 5 wt% toluene solution.

[0036]

[Table 1] (* The amount of the catalyst B used is a value converted into the amount of n-butyllithium that yields the same amount of lithium atoms as the contained lithium atoms, and the amount of the catalyst A used is n- in a 5 wt% n-hexane solution. Butyllithium amount)

Next, using various polybutadiene rubbers shown in Table 1, impact-resistant polystyrene was obtained by bulk polymerization described below. Stirrer, jacketed reactor, Table 2
And solvent, monomers, etc. were added in the types and proportions shown in Table 3, and then the conjugated diene rubber material No. shown in Table 1 was added. Polybutadiene rubber and n-octadecyl-
3- (4'-hydroxy-3 ', 5'-di-tert-
Butylphenol) propionate
Stir to dissolve. To this, 1 × 10 ⁻⁴ mol of di-tert-butyl peroxide was added with respect to 1 mol of the monomer, and polymerization was carried out at 110 ° C. for 3 hours, 140 ° C. for 5 hours, and 180 ° C. for 2 hours. After heating at 230 ° C. for 30 minutes, unreacted products were removed under reduced pressure, and the obtained polymer was pulverized.
Polydimethylsiloxane having a viscosity of 0 centistokes was added and pelletized by an extruder.

[0038]

[Table 2]

[0039]

[Table 3] As is clear from the results of Examples and Comparative Examples in Tables 2 and 3, the impact-resistant polystyrene using the carboxyl group-containing conjugated diene rubber of the present invention is a resin composition excellent in gloss and impact resistance. On the other hand, with the impact-resistant polystyrene other than the present invention, a resin excellent in gloss and impact strength could not be obtained, and one of the physical properties was inferior.

Examples 13 to 23 and Comparative Example 5 Carboxyl group-containing polybutadiene rubber was produced under the charged amounts and conditions shown in Table 4, and the specific polymerization method was the same as in Example 1. It was carried out in the way. Catalysts C, D, and E used as the organolithium-based catalysts were reaction products prepared under the conditions shown in Table 5, and were soluble in cyclohexane, which is a polybutadiene polymerization solvent. The divinylbenzene used to prepare the catalyst was a commercially available divinylbenzene containing 57% by weight of the isomer mixture, the balance being ethylvinylbenzene and diethylbenzene.

[0041]

[Table 4] (* Catalysts C, D, and E are shown in Table 5 for the preparation ratios, the reaction-produced catalysts prepared under the conditions, and the catalyst amounts are shown in terms of n-butyllithium equivalent)

[0042]

[Table 5] Using the obtained carboxyl group-containing polybutadiene rubber, bulk polymerization was carried out in the same manner as in Example 1, and the resulting high impact polystyrene was evaluated in the same manner as in Example 1 and the results and results are shown in Table 6 and Table 6. 7 shows.

[0043]

[Table 6]

[0044]

[Table 7] As is clear from Tables 6 and 7, the impact-resistant polystyrene using the carboxyl group-containing conjugated diene rubber of the present invention is a resin having excellent gloss and impact strength.

(Examples 24 to 32 and Comparative Examples 6 and 7,
8) Polymerization was carried out in the same manner as in Example 1 under the charged amounts and conditions shown in Table 8 to obtain various polybutadiene living polymers. Then, to this living polymer solution, a metallizing agent was added in the types and amounts shown in Table 6, and a metallation reaction was carried out at 50 ° C. for 1 hour. Then, 5 kg / cm ² (gauge pressure) of dried carbon dioxide was introduced into the autoclave. The temperature at this time was 10 ° C. Furthermore, 0.3 g of anhydrous hydrochloric acid was added and reacted for 30 minutes,
Then, the rubber solution was extracted into an 18-liter metal container,
10 liters of water was added, the mixture was stirred for 60 minutes, and the water was extracted. This operation was repeated 3 times to remove excess hydrogen chloride. In the polymer solution thus obtained, as a stabilizer,
6-di-tert-butyl-4-methylphenol (B
(HT) was added in an amount of 0.5 part by weight per 100 parts by weight of the polymer, and the solvent was removed by heating to obtain a carboxyl group-containing polybutadiene rubber shown in Table 6.

[0046]

[Table 8] (* Catalyst D is a reaction product catalyst prepared by reacting under the preparation ratio and conditions shown in Table 5, and the catalyst amount is shown in terms of n-butyllithium equivalent amount.
The amount of the catalyst A used was n- in a 5 wt% n-hexane solution.
Butyllithium amount. 1) is N, N, N ', N'-tetramethylethylenediamine. 2) is potassium tert-amylate. )

Using these rubbers, bulk polymerization was carried out in the same manner as in Example 1 to obtain high impact polystyrene shown in Tables 9 and 10.

[Table 9]

[0048]

[Table 10] As is clear from Table 9 and Table 10, the impact-resistant polystyrene of the present invention is a resin having excellent gloss and impact resistance.

[0049]

INDUSTRIAL APPLICABILITY The impact-resistant styrene-based resin composition of the present invention has an excellent balance of physical properties of impact resistance and gloss, as compared with conventional impact-resistant styrene-based resins, and is suitable for electronic devices such as TVs and VTRs. It can be used for a wide variety of purposes such as appliances, home electric appliances such as air conditioners and refrigerators, general appliances such as office automation equipment, stationery, toys, leisure sports goods, household goods, building materials / house parts, food containers, etc. It has an extremely excellent industrial effect.

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Claims (2)

(57) [Claims] 1. A polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography is 50,
The conjugated diene polymer in the range of 000 to 700,000 contains 2 to 25% by weight of the carboxyl group-containing conjugated diene rubber containing 0.015 to 2.0% by weight of the carboxyl group, and can ionically bond with the carboxyl group. Various compounds
An impact-resistant styrene-based resin composition, which is characterized by not containing it . 2. A polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography is 50,
In the conjugated diene polymer in the range of 000 to 700,000, 2 to 25% by weight of the carboxyl group-containing conjugated diene rubber containing 0.015 to 2.0% by weight of the carboxyl group, and a styrene-based monomer or styrene 98-75% by weight of a mixture of the system monomer and the copolymerizable monomer ,
A method for producing an impact-resistant styrene-based resin composition, which comprises radical polymerization by a bulk polymerization method, a bulk suspension polymerization method, or a solution polymerization method in the absence of a compound capable of forming an ionic bond with a xyl group .