JPWO2006093106A1 - Rubber composition for resin modification, process for producing the same, and rubber-reinforced resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for resin modification capable of obtaining a rubber-reinforced resin having high stability during storage and use, excellent gloss and color tone, excellent transparency, and less fish eyes. A production method and a rubber-reinforced resin composition using the rubber composition for resin modification are provided. SOLUTION: 100 parts by weight of a conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule, and a thioether compound thermal stabilizer and an acrylate compound heat A rubber composition for resin modification comprising 0.01 to 0.20 parts by weight of at least one heat stabilizer selected from the group consisting of stabilizers. Production of a resin-modifying rubber composition, wherein a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule is added to the conjugated diene polymer rubber, and then another thermal stabilizer is added. Method. A rubber-reinforced resin composition comprising the rubber composition for resin modification and a resin. [Selection figure] None

Description

  The present invention relates to a resin-modifying rubber composition suitable for modifying an aromatic vinyl resin such as a styrene resin, a method for producing the same, and a rubber-reinforced resin composition obtained by using the resin-modifying rubber composition Related to things. More specifically, the present invention is excellent in stability during production and storage, and can be used to obtain a rubber-reinforced resin composition excellent in gloss and color tone, excellent in transparency, and having less fish eyes. The present invention relates to a rubber composition for resin modification, a production method thereof, and a rubber-reinforced resin composition obtained using the rubber composition for resin modification.

  Aromatic vinyl resins such as styrene resins are used in a wide range of applications because of their good moldability, high rigidity, and easy availability of raw material monomers, and as thermoplastic resins used in various applications. is important. However, on the other hand, it has the disadvantage of being vulnerable to impact and fragile. For this reason, in applications that require impact resistance, reinforcement with rubber is performed. Typical aromatic vinyl resins reinforced with rubber include high impact polystyrene (HIPS) in which polystyrene is reinforced with crosslinked rubber particles, ABS resin in which styrene-acrylonitrile copolymer is reinforced with crosslinked rubber particles, and polyphenylene ether. And modified polyphenylene ether blended with HIPS. As rubbery polymers used to obtain these rubber-reinforced resins, conjugated diene polymers are most commonly used. However, since the conjugated diene polymer has a large amount of double bonds in its molecule, it has a problem of low stability against heat and oxygen during storage and use.

  In order to improve the stability of the conjugated diene polymer with respect to heat and oxygen, hydrogenation may be performed on a part of the unsaturated bond remaining in the conjugated diene polymer. However, hydrogenation is not possible in all applications, and an antioxidant is usually added.

For this reason, many studies have been conducted on antioxidants to be added to a resin-modifying rubber composition.
For example, Patent Document 1 discloses a rubber-reinforced styrene resin composition containing 0.002 wt% or more and less than 0.02 wt% of a phenolic antioxidant having a molecular weight of 400 to 700 and having one or more thioether structures in the molecule. Things are disclosed. However, in the presence of the diene polymer containing this antioxidant, there is a problem in the polymerization stability when polymerizing the styrene monomer.

  In Patent Document 2, by adding a three-component thioether-based heat stabilizer, a phosphite-based heat stabilizer, and a phenol-based heat stabilizer having a molecular weight of 500 or more, an impact modifier for thermoplastic resin is blended. It has been reported that a saturated polyester resin having excellent colorability and heat deterioration resistance can be obtained. However, in the study by the present inventors, when this impact modifier is applied to a thermoplastic resin other than a saturated polyester resin, only a resin having poor color tone due to poor heat resistance and heat deterioration can be obtained.

On the other hand, although not limited to resin modification, a device for preventing coloring or deterioration of the rubber itself has been devised.
In Patent Document 3, when a polymer obtained using an organolithium compound as an initiator is subjected to steam stripping to remove the solvent, the polymerization is stopped with water, alcohol or the like, preferably with an organic acid, and then a phenol-based stabilizer and tris. By adding a tris (disubstituted or trisubstituted phenyl) phosphite stabilizer such as (2,4-di-t-butylphenyl) phosphite, a polymer having excellent transparency and devitrification resistance can be obtained. It is described. However, in some cases, there is a problem that the transparency of the resin is lowered.

  In this way, in spite of a great variety of studies being conducted, until now it has excellent stability during production and storage, as well as excellent gloss and color tone, excellent transparency, The present condition is that the rubber composition for resin modification which can obtain rubber-reinforced resin with few fish eyes is not obtained.

JP 11-71489 A Japanese Patent Laid-Open No. 1-245044 JP-A-1-182307

Therefore, the object of the present invention is for resin modification, which has high stability during storage and use, and can be used to obtain a rubber-reinforced resin having excellent gloss and color tone, excellent transparency, and less fish eyes. It is to obtain a rubber composition.
Another object of the present invention is to provide a method for producing the rubber composition for resin modification.
Still another object of the present invention is to provide a rubber-reinforced resin composition using the rubber composition for resin modification.

  As a result of diligent research to achieve the above object, the present inventors have added a plurality of heat stabilizers having a specific structure to a conjugated diene polymer rubber in a specific ratio and used them. The present inventors have found that the problem can be solved, and have completed the present invention based on this knowledge.

Thus, according to the present invention, 100 parts by weight of a conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule, and a thioether compound thermal stabilizer and There is provided a rubber composition for resin modification comprising 0.01 to 0.20 parts by weight of at least one heat stabilizer selected from the group consisting of acrylate compound heat stabilizers.
Further, according to the present invention, 100 parts by weight of a conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule, and at least one thioether compound There is provided a rubber composition for resin modification comprising 0.01 to 0.20 parts by weight of a total of a heat stabilizer and at least one acrylate compound heat stabilizer.
In the rubber composition for resin modification of the present invention, the amount of the thioether compound heat stabilizer and the acrylate compound heat stabilizer is preferably 0.01 to 0.20 parts by weight.

In the rubber composition for resin modification of the present invention, the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is preferably a diphosphite heat stabilizer.
In the rubber composition for resin modification of the present invention, the amount of the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is 0.02 to 0.00 per 100 parts by weight of the conjugated diene polymer rubber. The amount is preferably 10 parts by weight, more preferably 0.03 to 0.09 parts by weight.

In the rubber composition for resin modification of the present invention, the thioether compound heat stabilizer preferably has a phenol group in its molecule.
In the rubber composition for resin modification of the present invention, the amount of the thioether compound heat stabilizer is preferably 0.01 to 0.10 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. More preferably, it is -0.09 weight part.
In the rubber composition for resin modification of the present invention, the acrylate compound heat stabilizer preferably has a phenol group in its molecule.
In the rubber composition for resin modification of the present invention, the amount of the acrylate compound heat stabilizer is preferably 0.01 to 0.10 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. More preferably, it is -0.09 weight part.

Further, according to the present invention, the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is added to the conjugated diene polymer rubber, and then the other heat stabilizer is added. A method for producing a rubber composition for resin modification of the invention is provided.
In the method for producing a rubber composition for resin modification according to the present invention, the conjugated diene polymer rubber obtained by using an organolithium compound as a polymerization initiator has an amount of less than 1 equivalent to lithium of the organolithium compound. After adding at least one acid selected from the group consisting of organic acids, inorganic acids and Lewis acids, a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is added to the conjugated diene polymer rubber. It is preferable to do.

Further, in the method for producing a resin-modifying rubber composition of the present invention, at least the addition of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule to the conjugated diene polymer rubber, other than the heat stabilizer It is preferable to carry out before the compounding agent is added to the conjugated diene polymer rubber.
Furthermore, in the method for producing a resin-modifying rubber composition of the present invention, all the heat stabilizers are added to the conjugated diene polymer rubber, and before the compounding agents other than the heat stabilizer are added to the conjugated diene polymer rubber. It is preferable to carry out.

Furthermore, according to the present invention, there is provided a rubber-reinforced resin composition comprising the above-described resin-modifying rubber composition of the present invention and a base resin.
In the rubber-reinforced resin composition, the base resin preferably contains at least an aromatic vinyl resin.

  According to this invention, the rubber composition for resin modification excellent in stability at the time of manufacture and storage can be obtained. Further, by using this resin-modifying rubber composition, it is possible to obtain a rubber-reinforced resin composition that is excellent in gloss and color tone, excellent in transparency, and has little fish eye.

  The rubber composition for resin modification of the present invention comprises 100 parts by weight of a conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule, and thioether. It contains 0.01 to 0.20 parts by weight of at least one heat stabilizer selected from the group consisting of a compound heat stabilizer and an acrylate compound heat stabilizer.

(Conjugated diene polymer rubber)
The conjugated diene polymer rubber used in the present invention is a conjugated diene homopolymer rubber or a copolymer rubber of a conjugated diene and a monomer copolymerizable therewith.
In the conjugated diene copolymer rubber, the ratio of the conjugated diene monomer unit is not particularly limited, but is preferably 40% by weight or more, and more preferably 50 to 75% by weight. When a conjugated diene copolymer rubber having the above ratio is within this range, the resulting rubber-reinforced resin composition has excellent impact resistance.

The conjugated diene monomer for obtaining this conjugated diene polymer rubber is not particularly limited, and specific examples thereof include butadiene, isoprene, 2,3-dimethylbutadiene, 1,3-pentadiene and the like. . Among these, butadiene and isoprene are preferable, and butadiene is particularly preferable.
These conjugated diene monomers may be used alone or in combination of two or more.

The monomer copolymerizable with the conjugated diene is not particularly limited. Specific examples thereof include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-t-butylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 5 Aromatic vinyl monomers such as t-butyl-2-methylstyrene; non-such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, dicyclopentadiene, 5-ethylidene-2-norbornene Conjugated diene monomers; (meth) acrylic acid ester monomers such as methyl acrylate, methyl methacrylate, ethyl acrylate and butyl acrylate; α, β-ethylene such as acrylonitrile, methacrylonitrile and α-chloroacrylonitrile Unsaturated nitrile monomer; and the like.
Among these, aromatic vinyl monomers are preferable, and styrene is particularly preferable.

  When the copolymer is used as the conjugated diene polymer rubber, the bonding mode of each monomer is selected according to the purpose and application. For example, in the case of using an aromatic vinyl-conjugated diene copolymer, random copolymerization is selected when the impact strength is most important, and a block copolymer is selected for use in which gloss is important.

When an aromatic vinyl-conjugated diene copolymer is used as the conjugated diene polymer rubber, the aromatic vinyl content is usually 3 to 60% by weight, preferably 10 to 50% by weight, more preferably 20 to 35% by weight. When it is, it is excellent in impact strength and transparency.
In the case of a block copolymer, the aromatic vinyl block ratio is preferably 70% by weight or more and more preferably 80% by weight or more when the gloss is important. If the balance between impact strength and gloss is the purpose, the block ratio is preferably 20 to 80% by weight, more preferably 30 to 75% by weight.
The aromatic vinyl block rate is a unit amount forming a chain having a molecular weight of about 1,000 or more consisting of only an aromatic vinyl monomer unit in all aromatic vinyl monomer units in the block copolymer rubber. Is a numerical value indicating I.V. M.M. It is a value measured according to the osmium acid decomposition method described in Kolthoff et al., Journal of Science (J. Polym. Sci.), Volume 1, p429 (1948).

The bonding mode in the conjugated diene monomer unit is not particularly limited, but the ratio of the vinyl bonding unit is usually 1 to 90 mol%, preferably 7 to 50 mol%, more preferably 10 to 40 mol%.
When the vinyl bond unit amount is within this range, a molded product having excellent impact resistance and gloss and having little variation in gloss depending on the surface part in an injection molded product or the like is obtained from the rubber-reinforced resin composition of the present invention. Can do.
The amount of the monomer other than the aromatic vinyl monomer that can be copolymerized with the conjugated diene is usually 40% by weight or less, preferably 30% by weight or less, more preferably 15% in all monomers. % By weight or less.

  Specific examples of the conjugated diene polymer rubber include polymer rubbers composed only of conjugated diene monomer units such as butadiene rubber, isoprene rubber and butadiene-isoprene rubber; styrene-butadiene rubber, styrene-isoprene rubber, styrene-butadiene- Random copolymer rubber of aromatic vinyl monomer such as isoprene rubber and conjugated diene monomer; styrene-butadiene block copolymer rubber, styrene-isoprene block copolymer rubber, styrene-butadiene-isoprene block copolymer And a block copolymer rubber of an aromatic vinyl monomer such as a combined rubber and a conjugated diene monomer.

  The molecular weight of the conjugated diene polymer rubber is not particularly limited, but is usually 50,000 to 1,000,000, preferably 100,000 to 600,000, more preferably in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography. Gives a resin composition having excellent impact strength and gloss when 150,000 to 500,000.

  When the conjugated diene polymer rubber is an aromatic vinyl-conjugated diene copolymer rubber, the 5% styrene solution viscosity of the aromatic vinyl-conjugated diene block copolymer rubber is 5 to 200 mPa · s, preferably 10 to 100 mPa · s. When s, more preferably 15 to 70 mPa · s, the impact strength of the resin composition and the handleability of the solution during production of the resin composition are excellent.

  Although there is no restriction | limiting in particular in the glass transition temperature (In the case of a block copolymer, the glass transition temperature of the conjugated diene polymer block part), as for conjugated diene polymer rubber, -40 degrees C or less is preferable, More preferably- 90 to -50 ° C, more preferably -85 to -55 ° C.

The polymerization method of the conjugated diene polymer rubber is not particularly limited, and a conventionally known method can be adopted.
For example, in a hydrocarbon solvent, organic alkali metal catalyst, organic alkaline earth metal catalyst, or organic acid salt of transition metal such as cobalt, nickel, neodymium, samarium, gadolinium, etc. Depending on the conditions, other monomers used are polymerized to produce a polymer solution.
Conjugated diene polymer rubber having the above glass transition temperature when solution polymerization is performed using an organic alkali metal catalyst, an organic alkaline earth metal catalyst, or an organic acid salt of a transition metal such as cobalt, nickel, neodymium, samarium, or gadolinium Can be easily obtained.
Among these, a method using an organic alkali metal catalyst is preferable.

  As the organic alkali metal catalyst, an organic lithium compound in which one or more lithium atoms are bonded in the molecule is preferable. Examples of the organic lithium compound include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium, hexamethylene dilithium, butadienyl lithium, and isoprenyl dilithium. be able to. These organolithium compounds may be used alone or in combination of two or more.

The polymerization solvent is not particularly limited as long as it is inert to the polymerization initiator, and for example, a chain hydrocarbon solvent, a cyclic hydrocarbon solvent, or a mixed solvent thereof is used.
Examples of chain hydrocarbon solvents include n-butane and isobutane; 1-butene, isobutylene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene and n-pentane Examples thereof include chain alkanes and alkenes having 4 to 5 carbon atoms such as isopentane and neo-pentane.
Specific examples of the cyclic hydrocarbon solvent include aromatic compounds such as benzene, toluene and xylene; and alicyclic hydrocarbons such as cyclohexane.
These polymerization solvents may be used alone or in combination of two or more.

During polymerization, adjustment of polymerization rate, variation of microstructure (cis, trans, vinyl ratio) of polymerized conjugated diene monomer unit, adjustment of reactivity ratio of conjugated diene monomer and vinyl aromatic compound, etc. For the purpose, a polymerization regulator can be used.
As the polymerization regulator, an aromatic or aliphatic ether having a relative dielectric constant of 2.5 to 5.0, or a polar compound such as a tertiary amine can be preferably used.
Specific examples of such polar compounds include aromatic ethers such as diphenyl ether and anisole; aliphatic ethers such as diethyl ether, dibutyl ether and ethylene glycol dibutyl ether; tertiary monoamines such as trimethylamine, triethylamine and tripropylamine; Tertiary polyamines such as N, N, N ′, N′-tetramethylethylenediamine and N, N, N ′, N′-tetraethylethylenediamine; and the like, and one or more of these are preferably used. Is done.
In addition to the above, examples of the polar compound include thioethers; phosphines such as triphenylphosphine; phosphoramides such as hexamethylphosphoramide; alkylbenzene sulfonates; alkoxides of potassium or sodium;

The polymerization temperature for producing the conjugated diene polymer rubber is generally -10 ° C to 150 ° C, preferably 40 ° C to 120 ° C. The time required for the polymerization varies depending on the conditions, but is usually within 48 hours, particularly preferably 0.5 to 10 hours. When it is difficult to control the reaction temperature, it is preferable to control the temperature by reflux cooling using a reaction vessel provided with a reflux condenser.
The polymerization is desirably performed in an atmosphere of an inert gas such as nitrogen gas. The polymerization pressure is not particularly limited as long as it is carried out in a pressure range sufficient to maintain the monomer and solvent in the liquid phase within the above polymerization temperature range.

The polymerization method of each monomer is not particularly limited, and batch polymerization in which the total amount of monomers and the total amount of initiator are collectively charged into the polymerization system and reacted, and these are continuously reacted while being supplied to the polymerization system. Usually used, such as continuous polymerization, a method in which a part of the monomer and the initiator is used for polymerization to a predetermined conversion rate, and then the remaining monomer and initiator are added to continue the polymerization. Any of the methods may be used.
Moreover, what is necessary is just to stop a polymerization reaction using polymerization stoppers, such as alcohol, as needed.
Further, the conjugated diene polymer rubber may be one obtained by hydrogenating after polymerization to saturate at least a part of the unsaturated bonds in the polymer.

  The conjugated diene polymer rubber solution after polymerization may be acidic or alkaline due to various metal compounds used as a polymerization catalyst. Therefore, before operations such as coagulation and heat stabilizer blending, it is preferable to neutralize with a basic or acidic compound corresponding to the liquidity.

Examples of the basic compound used for the neutralization include alkali metal hydroxides; alkali metal carbonates; alkali metal hydrogen carbonate salts; ammonia; amine compounds such as ethanolamine.
Further, as the acidic compound, Lewis acid can be used in addition to inorganic acid and organic acid.
Examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, boric acid, phosphoric acid, and carbon dioxide gas.
Examples of organic acids include carboxylic acids such as benzoic acid and citric acid, as well as sulfonic acids, sulfinic acids, and phenolic compounds.
Examples of Lewis acids include aluminum chloride, iron chloride, boron fluoride and the like.
Of these, organic acids are preferable, and carboxylic acid is particularly preferable.

The amount of these neutralizing agents is preferably used less than the amount necessary to completely neutralize the catalyst metal residue. Preferably, the amount is 0.1 to 0 relative to the amount necessary for complete neutralization (for example, when an organic lithium compound is used as the polymerization initiator, relative to the lithium of the organic lithium compound used). 0.9 equivalent, more preferably 0.2 to 0.7 equivalent, and particularly preferably 0.3 to 0.6 equivalent.
By making the use amount of the neutralizing agent within this range, precipitation of the neutralizing agent in the conjugated diene polymer rubber can be completely prevented, and the transparency of the rubber-reinforced resin composition obtained using the neutralizing agent can be reduced. It will be good.

  In the rubber composition for resin modification of the present invention, other rubbers may be blended in addition to the conjugated diene polymer rubber.

The rubber composition for resin modification of the present invention contains a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule as an essential heat stabilizer.
The phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is not particularly limited, but is preferably a diphosphite heat stabilizer.
Specific examples thereof include dialkylpentaerythritol diphosphites such as di (tridecyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite; di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di -T-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol Diphosphite, bis (2,4-di-t-butyl-6-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-isopropylphenyl) pentaerythritol diphosphite, Bis (2,6-di-t-butyl- -Sec-butylphenyl) pentaerythritol diphosphite, diarylpentaerythritol diphosphites such as bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite; and other pentaerythritol diphosphites such as , Tetra (tridecyl) isopropylidene diphenyl diphosphite, tetra (tridecyl) -1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butane diphosphite, tetra (C ₁₂ or more) C ₁₅ following mixed alkyl) -4,4'-isopropylidene diphenyl diphosphite, tetra (tridecyl) -4,4'-butylidene bis (2-t-butyl-5-methylphenyl) diphosphite, tetra (tridecyl) - 4,4′-butylidenebis (3-methyl) (Lu-6-tert-butylphenol) diphosphite, bis (octylphenyl) -bis [4,4′-butylidenebis (3-methyl-6-tert-butylphenol)]-1,6-hexanediol diphosphite, etc. Can do.
The phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule is tris [2-t-butyl-4- (3-t-butyl-4-hydroxy-5-methylphenylthio) -5- It may have two or more thioether structures in the molecule, such as methylphenyl] phosphite.

Of these phosphite compound heat stabilizers having two or more phosphorus atoms in the molecule, diphosphite heat stabilizers that are liquid at room temperature are preferred from the viewpoint of uniform dispersibility. Further, the molecular weight is preferably 700 or more, and more preferably 800 or more.
In the rubber composition for resin modification, the amount of the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is preferably 0.01 to 0.20 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. Is 0.02 to 0.10 parts by weight, more preferably 0.03 to 0.09 parts by weight.
When the amount used is within this range, the conjugated diene polymer rubber is less likely to be colored and deteriorated, the polymerization stability during the production of the rubber-reinforced resin composition, and the color tone, transparency and the resulting rubber-reinforced resin composition Good gloss.

  When a phosphite compound heat stabilizer having one phosphorus atom in the molecule is used instead of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, the gel in the conjugated diene polymer rubber The amount increases, storage stability becomes poor, and the color tone and transparency of the resulting resin-modifying rubber composition and rubber-reinforced resin composition are inferior.

The rubber composition for resin modification of the present invention is at least selected from the group consisting of a thioether compound heat stabilizer and an acrylate compound heat stabilizer in addition to a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule. It is necessary to further contain a kind of heat stabilizer.
The amount of the at least one heat stabilizer needs to be 0.01 to 0.20 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. When the amount used is within this range, the conjugated diene polymer rubber is less likely to be colored and deteriorated, the polymerization stability during the production of the rubber-reinforced resin composition, and the color tone, transparency and the resulting rubber-reinforced resin composition Good gloss.

  These thioether compound heat stabilizers and acrylate compound heat stabilizers may be used alone or in combination. When both are used in combination, the total amount used needs to be 0.01 to 0.20 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. When a thioether compound heat stabilizer and an acrylate compound heat stabilizer are used in combination, a further excellent heat stability effect can be obtained as compared with the case where each is used alone.

The thioether compound thermal stabilizer is not particularly limited as long as it is a thermal stabilizer having a thioether structure in which a sulfur atom is bonded to two hydrocarbon groups, but preferably has two or more thioether structures in the molecule.
Specific examples thereof include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, laurylstearyl-3,3 ′. -Thiodipropionate, pentaerythritol-tetrakis (3-laurylthiopropionate), 3,9-bis- (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] Undecane; 4,6-bis (octylthiomethyl) -o-cresol, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4 -Bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine; and the like.
One of these thioether compound heat stabilizers may be used alone, or two or more thereof may be used in combination.
Of these thioether compound heat stabilizers, phenol compounds, that is, those having a phenol group in the molecule are preferred.

The amount of the thioether compound heat stabilizer used is 0.01 to 0.10 parts by weight, preferably 0.02 to 0.09 parts by weight, more preferably 0.03 to 0 parts per 100 parts by weight of the conjugated diene polymer rubber. 0.08 part by weight.
When the amount used is within this range, the conjugated diene polymer rubber is less likely to be colored and deteriorated, the stability during storage is good, the stability during production of the rubber-reinforced resin composition is good, and the resulting rubber reinforcement The color tone of the resin composition becomes good.

The acrylate compound heat stabilizer is a heat stabilizer having an acryloyl group or a methacryloyl group in the molecule. Any other structure may be used as long as it has one or more of these groups in the molecule.
Preferable acrylate compound heat stabilizers include those having a structure of an acrylic ester or methacrylic ester having a phenol group, which is obtained from an alcohol having a phenol group in the molecule and acrylic acid or methacrylic acid. Specific examples thereof include 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-3,5 -Di-t-amylphenyl) ethyl] -4,6-di-t-amylphenylacrylate.
This acrylate compound heat stabilizer is preferable because it does not cause coloring of the rubber composition.

The amount of the acrylate compound heat stabilizer used is 0.01 to 0.10 parts by weight, preferably 0.02 to 0.09 parts by weight, more preferably 0.03 to 0 parts per 100 parts by weight of the conjugated diene polymer rubber. 0.08 part by weight.
When the amount used is within this range, the conjugated diene polymer rubber is less likely to be colored and deteriorated, the stability during storage is good, the stability during production of the rubber-reinforced resin composition is good, and the resulting rubber reinforcement The color tone of the resin composition becomes good.

The rubber composition for resin modification of the present invention contains a heat stabilizer other than a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, a thioether compound heat stabilizer, and an acrylate compound heat stabilizer. Also good.
Such heat stabilizers include phosphite compound heat stabilizers having one phosphorus atom in the molecule, phosphonite compound heat stabilizers having two or more phosphorus atoms in the molecule, thioether structures and acryloyl groups in the molecule. Or the phenol compound heat stabilizer which does not have a methacryloyl group etc. can be mentioned.
The amount of these heat stabilizers used is 0.01 to 0.10 parts by weight, preferably 0.02 to 0.09 parts by weight, more preferably 0.03 to 0 parts per 100 parts by weight of the conjugated diene polymer rubber. 0.08 part by weight.

  Specific examples of the phosphite compound thermal stabilizer having one phosphorus atom in the molecule include tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2, 5-di-t-butylphenyl) phosphite, tris (2,4-bis (1,1-dimethylpropyl) phenyl) phosphite, tridecylphosphite, octyldiphenylphosphite, di (decyl) monophenylphosphite , Tris (3,5-di-t-butyl-4-hydroxyphenyl) phosphite, tris (mono-, di-mixed nonylphenyl) phosphite, 2,2'-methylenebis (4,6-di-t- Butylphenyl) -2-ethylhexyl phosphite, 2,2'-methylenebis (4,6-di-t-butylphenyl) -2-oct Tridecyl phosphite, 2,2'-ethylidene-bis (4,6-di -t- butyl-phenyl) fluoro phosphite, and the like.

  Specific examples of the phosphonite compound heat stabilizer having two or more phosphorus atoms in the molecule include tetrakis (2,4-di-t-butylphenyl) biphenylene diphosphonite, tetrakis (2,4-di-t-butyl). And -5-methylphenyl) biphenylene diphosphonite.

  Specific examples of the thermal stabilizer for a phenol compound other than a phenol compound having a thioether structure in which a sulfur atom is bonded to two hydrocarbon groups, an acryloyl group or a methacryloyl group in the molecule include tetrakis [methylene-3 (3 ′, 5 '-Di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, octadecyl-3- (3,5-di-) t-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) pro Onate], 1,3,5-tris- (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid, 2,2'-methylene-bis- (4-methyl-6-t- Butylphenol), 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10- Tetraoxaspiro [5.5] undecane, 4-hydroxymethyl-2,6-di-t-butylphenol, 2,6-di-t-butyl-4-ethylphenol, butylated hydroxyanisole, 2,2′- Dihydroxy-3,3′-dicyclohexyl-5,5′-dimethyl-diphenylmethane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 4 4′-butylidenebis (6-t-butyl-m-cresol, 4,4′-thiobis (3-methyl-6-t-butylphenol), bis (3-cyclohexyl-2-hydroxy-5-methylphenyl) methane, 2,2'-methylenebis (4-ethyl-6-t-butyl-phenol), 1,1-bis (2'-methyl-4'-hydroxy-5'-t-butyl-phenyl) butane, etc. Can do.

In order to prepare the rubber composition for resin modification of the present invention, various heat stabilizers may be added to the conjugated diene polymer rubber, and the method is not particularly limited.
There is no limitation in particular in the addition method of each heat stabilizer. After the polymerization, it may be added to the coagulated conjugated diene polymer rubber, but it is preferable to add it to the solution of the conjugated diene polymer rubber before the coagulation because the heat stabilizer can be easily dispersed uniformly.
The shape of the heat stabilizer when added to the conjugated diene polymer rubber may be as it is or in the form of a solvent solution, but is preferably a solvent solution having a concentration of 1 to 50% by weight.

  In the method for producing a rubber composition for resin modification according to the present invention, the order in which the heat stabilizer is added to the conjugated diene polymer rubber is not particularly limited, but the heat of the phosphite compound having two or more phosphorus atoms in the molecule. In order to prevent coloring of the conjugated diene polymer rubber, it is preferable to add a heat stabilizer other than this after adding the stabilizer.

In the present invention, the time when the heat stabilizer is added to the conjugated diene polymer rubber is not particularly limited, and may be any time after polymerization.
When an organolithium compound is used as a polymerization initiator, from the viewpoint of preventing coloring of the resulting resin-modifying rubber composition, the conjugated diene polymer rubber obtained by polymerization is equivalent to 1 equivalent to the organolithium compound. After adding at least one acid selected from the group consisting of an organic acid, an inorganic acid and a Lewis acid, a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule is added to the conjugated diene weight. It is preferable to add to the united rubber and then to add another heat stabilizer.
Various compounding agents such as liquid paraffin, calcium carbonate, silica, flame retardant, and light stabilizer can be added to the rubber composition for resin modification of the present invention as necessary. In the method, it is preferable to add at least a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule to the conjugated diene polymer rubber before adding these compounding agents. It is preferred to add a stabilizer.

The rubber-reinforced resin composition of the present invention comprises the above-described rubber composition for resin modification of the present invention and a base resin.
Although base resin is not specifically limited, An aromatic vinyl resin, an olefin resin, etc. can be illustrated.
Examples of aromatic vinyl resins include acrylonitrile-acrylate-styrene resin, acrylonitrile-ethylene-styrene resin, acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, polystyrene resin, high impact polystyrene resin, methyl methacrylate-butadiene-styrene resin. And methyl methacrylate-styrene resin.
Examples of the olefin resin include polyethylene and polypropylene.
Furthermore, the base resin may be an engineering resin such as polyphenylene ether, polyamide, polycarbonate, polyacetal, polyester, in addition to the aromatic vinyl resin and olefin resin.
These base resin may be used individually by 1 type, or may use 2 or more types together.
The rubber-reinforced resin composition of the present invention preferably contains at least an aromatic vinyl resin among these base resins.

The amount of the rubber composition for resin modification in the rubber-reinforced resin composition is a weight ratio of conjugated diene polymer rubber / base resin in the rubber composition for resin modification, usually 2/98 to 25/75. The range is preferably 3/97 to 20/80, more preferably 5/95 to 15/85.
If the amount of the conjugated diene polymer rubber is too large, the gloss, rigidity, weather resistance, hardness, etc. of the molded product obtained from the rubber-reinforced resin composition are inferior. If the amount of the base resin is too large, the impact resistance of the molded product Lack of sex.

  The method for producing the rubber-reinforced resin composition of the present invention is not particularly limited, and the base resin and the rubber-reinforced resin composition may be mixed by any method, and the presence of the resin-modifying rubber composition A monomer (hereinafter sometimes referred to as a “resin monomer”) that is a raw material for the base resin may be polymerized, but according to the latter method, a composition having excellent impact resistance is obtained. It is preferable because it can be obtained.

  The base resin and the rubber-reinforced resin composition can be mixed using various kneading apparatuses such as a single screw extruder or a multi-screw extruder such as a twin screw, a Banbury mixer, a roll, and a kneader. The mixing temperature is preferably in the range of 100 to 250 ° C.

  When the resin monomer is polymerized in the presence of the resin modifying rubber composition, a polymerization stock solution in which the resin modifying rubber composition is dissolved or dispersed in the resin monomer is polymerized in a reactor. The polymerization method is not particularly limited, and any of a bulk polymerization method, a suspension polymerization method, a solution polymerization method, an emulsion polymerization method and the like may be used.

In the bulk polymerization method, a resin-modifying rubber composition is dissolved or dispersed in a resin monomer, a molecular weight regulator, a lubricant, etc. are added as necessary, an initiator is added, and an inert gas atmosphere is added. The polymerization may be carried out while stirring. When the aromatic vinyl monomer is polymerized by a bulk polymerization method, the polymerization temperature is preferably 60 to 200 ° C.
In the suspension polymerization method, a resin-modified rubber composition is dissolved in a resin monomer in the same manner as in the bulk polymerization method, and a molecular weight regulator, a lubricant, etc. are added as necessary, and an initiator is added. Can be dispersed in an aqueous solution in which the suspension stabilizer is dissolved, polymerized while maintaining the suspended state, and the suspension stabilizer can be sufficiently washed and removed after the polymerization to recover the resin composition. . When the aromatic vinyl monomer is polymerized by the suspension polymerization method, the polymerization is preferably completed at 60 to 150 ° C.
In the solution polymerization method, as in the bulk polymerization method, the rubber composition for resin modification is dissolved in the resin monomer, and a molecular weight regulator, a lubricant, and an organic solvent for viscosity adjustment are added as necessary. Then, an initiator may be added and polymerization may be performed while stirring in an inert gas atmosphere. When the aromatic vinyl monomer is polymerized by a solution polymerization method, the polymerization temperature is preferably 60 to 200 ° C.
Bulk polymerization may be performed until about 10 to 50% by weight of the resin monomer is polymerized, and then polymerization may be performed by a two-stage polymerization method in which suspension polymerization or solution polymerization is performed.
After completion of the polymerization, the rubber-reinforced resin composition is recovered by performing a treatment such as coagulation and drying by a conventional method.

  In the rubber-reinforced resin composition of the present invention, when the resin is a thermoplastic resin, the lower limit of the melt flow rate measured at 200 ° C. under a load of 5 kg is preferably 0.1, more preferably, according to JIS K6871. Is 0.5, and the upper limit is preferably 20. When the melt flow rate is within the above range, kneading can be facilitated, the dispersion of the rubber composition for resin modification becomes uniform, and the resin modification effect is exhibited well.

If necessary, the rubber-reinforced resin composition of the present invention may contain various compounding agents that are usually used in the resin industry within a range that does not impair the effects of the present invention.
As such compounding agents, mineral oil, liquid paraffin, organic or inorganic fillers, stabilizers other than heat stabilizers other than weathering stabilizers and light stabilizers, plasticizers, lubricants, ultraviolet absorbers, colorants, Examples include pigments, release agents, antistatic agents, flame retardants, and the like.

Hereinafter, the present invention will be described more specifically with reference to reference examples, examples and comparative examples. In addition, the part and% in each example are mass references | standards unless there is particular notice.
Each characteristic was evaluated by the following method.

(Molecular weight of polymer)
The molecular weight is calculated in terms of polystyrene by gel permeation chromatography using tetrahydrofuran as a carrier. Specifically, the measurement is performed using two high performance liquid chromatography apparatuses HLC8220 and two columns GMH-HR-H (both manufactured by Tosoh Corporation).
(Aromatic vinyl compound content in conjugated diene polymer rubber (aromatic vinyl-conjugated diene copolymer))
Measured by proton NMR.
(Vinyl bond amount of conjugated diene monomer unit in conjugated diene polymer rubber)
Measured by proton NMR.
(Aromatic vinyl block rate)
Measured by osmium acid decomposition method.

(Polymerization stability of resin monomer in the presence of resin-modifying rubber composition)
A 10% styrene solution of the rubber composition for resin modification is prepared. This is heated to 125 ° C., and immediately after reaching 125 ° C., 1 part of n-dodecyl mercaptan is added and maintained at 125 ° C. as it is. Next, the polymerization conversion rate is measured every 30 minutes, the measurement is terminated when the polymerization conversion rate exceeds 70%, and the polymerization start time is determined by the following method.
This measurement is repeated three times. In three measurements, when the difference between the maximum value and the minimum value of the polymerization initiation time obtained was less than 30 minutes, “polymerization stability was good”, and when the difference was 30 minutes or more, “polymerization stability” Is not good. "

(Method for determining polymerization start time)
The time when the horizontal axis is time (the time when n-dodecyl mercaptan is added is 0), the time when the vertical axis is the polymerization conversion rate, the polymerization conversion rate is plotted on a graph of polymerization conversion rate, and the polymerization conversion rate is 20% or more. An approximate straight line is obtained by the least square method using points. The time at the intersection of this approximate straight line and the X axis (horizontal axis) is taken as the polymerization start time. Even when this numerical value is negative, the numerical value is used.

(Initial color tone of resin-modifying rubber composition (APHA))
The 5.43% toluene solution of the resin modifying rubber composition is measured in accordance with ASTM D125 using a color measuring device (trade name “OME-2000” manufactured by Nippon Denshoku Industries Co., Ltd.).

(Presence or absence of precipitation of neutralizing agent)
The rubber composition for resin modification is pressed at 100 ° C. to prepare a sheet having a thickness of 2 mm. The degree of cloudiness of the obtained transparent sheet is visually determined.

(Amount of gel in the rubber composition for resin modification)
5 g of a sample is put into 95 g of toluene placed in an Erlenmeyer flask and stirred for 4 hours with a magnetic stirrer, and then the gel (toluene insoluble matter) is filtered using a filter paper (No. 2). When the entire filter paper is dyed with osmic acid, the gel is dyed. Therefore, the number of gels is visually counted and determined according to the following criteria.
1: No gel having a diameter of 0.5 mm or more 2: Several gels having a diameter of about 0.5 to 1 mm are observed.
3: A gel having a diameter of about 1 mm can be seen on one side of the filter paper.
4: In addition to a gel having a diameter of about 1 mm, a gel having a diameter of about 2.5 mm is observed.

(Storage stability of resin-modified rubber composition)
The sheet (manufacturing method, size, etc.) is left in a gear oven (2 ventilations / 1 hour) at 70 ° C. for 1 week.
Thereafter, the color tone of the sheet is visually observed. When there is no coloring and it is transparent, it is determined as “good”.

(Gloss of rubber-reinforced resin composition)
Using a rubber-reinforced resin composition pellet, a mold having a length of 9 cm, a width of 5 cm and a thickness of 2 mm using an injection molding machine SAV-30 / 30 (manufactured by Yamashiro Seiki Co., Ltd .; mold temperature 50 ° C., nozzle tip temperature 240 ° C.) In addition, a test piece is manufactured by injecting perpendicularly in the thickness direction from a position 1 cm (8 cm from the other end) from one end to the vertical direction on the center line in the horizontal direction.
Using this test piece, measurement is performed at an incident angle of 60 ° in accordance with JIS Z 8741. A glossiness of more than 85 is defined as “good”, and a glossiness of 85 or less is defined as “poor”.
In addition, the measurement is performed on a portion (gate portion) and a portion 6 cm (end portion) each having a distance of 1 cm from the injection port on the lateral center line of the test piece and averaging them.

(Color tone of rubber-reinforced resin composition)
The rubber-reinforced resin composition is press-molded at 200 ° C. to obtain a 50 mm × 50 mm × 3 mm sheet. The color tone of this sheet is visually determined. When it is milky white, “good” is set.

(Fisheye in rubber-reinforced resin composition)
The rubber-reinforced resin composition was extruded at 200 ° C. from a 40 mm short axis extruder equipped with a 30-cm wide T-die. A film having a thickness of about 0.2 mm is obtained by stretching 1.5 times, and after 30 minutes, the number of fish eyes having a diameter of 3 mm or more present in 30 cm × 10 cm of the film is counted. If there are 5 or more, “Yes” is set.

(Transparency of MBS resin)
Resin monomer so that the rubber-reinforced resin composition obtained by polymerizing the resin monomer in the presence of the resin-modifying rubber composition has the same refractive index as that of the resin-modifying rubber composition. The composition of the body is adjusted and polymerization is performed to obtain a rubber-reinforced resin composition. From the obtained rubber-reinforced resin composition, a sheet of 50 mm × 50 mm × 3 mm is prepared according to ASTM D-1003, and the light transmittance thereof is measured. A light transmittance of 85 or more and no yellowing or turbidity is defined as “good”.

(Reference Example 1)
(Preparation of conjugated diene polymer rubber (a1))
After distillation, 600 kg of cyclohexane purified with molecular sieve 3A and 60 kg of butadiene purified in the same manner were charged into an autoclave with a cooling condenser, jacket and stirrer having a capacity of 2,000 liters substituted with nitrogen, and adjusted to 50 ° C. To this, 50 mmol of tetramethylethylenediamine and 1.05 mol of n-butyllithium were added to initiate polymerization. Ten minutes later, 60 kg of 1,3-butadiene was added over 30 minutes. 30 minutes after the completion of the addition, when the polymerization conversion rate was almost 100%, 80 kg of styrene purified as described above was added over 30 minutes while maintaining the temperature at 80 ° C. Then, after continuing reaction for 50 minutes, after adding 2.1 mol of isopropyl alcohol and continuing stirring for 5 minutes, the solution of conjugated diene polymer rubber (a1) was obtained. The weight average molecular weight of the conjugated diene polymer rubber (a1) was 340,000, and the molecular weight distribution was 1.2. The styrene content was 39.8%, the 1,2-vinyl structure of the butadiene portion was 10.5 mol%, and the styrene block ratio was 95%.

(Preparation of conjugated diene copolymer rubber (b))
600 kg of cyclohexane, 25 kg of butadiene, and 66 kg of styrene, which were purified in the molecular sieve part 3A after distillation, were charged into a 2,000 liter autoclave equipped with a nitrogen-cooled condenser, jacket and stirrer, and adjusted to 50 ° C. To this was added 290 mmol of tetramethylethylenediamine and 2.67 mol of n-butyllithium to initiate polymerization. After 15 minutes, while maintaining the temperature at 65 ° C., 40 kg of 1,3-butadiene was added over 15 minutes. Subsequently, 30 kg of 1,3-butadiene was added over 15 minutes, and 10 kg of 1,3-butadiene was further added over 15 minutes. When the addition was completed 20 minutes, the polymerization conversion rate was about 100%. 4 kg of 1,3-butadiene was added over 1 minute. Then, when the reaction was continued for 10 minutes, 670 mmol of tetramethoxysilane was added. Next, after the reaction was continued for 30 minutes, 5.3 mol of isopropyl alcohol was added and stirring was continued for 5 minutes to obtain a solution of the conjugated diene polymer rubber (b). The weight average molecular weight of the conjugated diene polymer rubber (b) was 320,000, and the molecular weight distribution was 1.3. The styrene content was 25.2%, and the 1,2-vinyl structure content of the butadiene portion was 17.8 mol%.

(Example 1)
(Preparation of resin-modifying rubber composition (R))
A 10% cyclohexane solution of tetra (tridecyl) -4,4′-butylidenebis (2-tert-butyl-5-methylphenyl) diphosphite [a phosphite compound thermal stabilizer having two or more phosphorus atoms in the molecule] is used as a conjugated diene. It added to the solution of 50 degreeC conjugated diene polymer rubber (a1) so that the quantity of heat stabilizer might be 0.10 part with respect to 100 parts of polymer rubber (a), and it stirred for 5 minutes. Thereafter, a 10% cyclohexane solution of 4,6-bis (octylthiomethyl) -o-cresol [thioether compound thermal stabilizer] was added to 0.09 part, and the mixture was further stirred for 5 minutes.
The solidified crumb desolvated by the steam stripping method is adjusted to a moisture content of about 10% through a squeezing machine, dried in an extrusion dryer at about 150 ° C., and then dried in hot air at 70 ° C. to give a rubber composition for resin modification (R1) was obtained.
Table 1 shows the results of the evaluation of the properties of this resin-modifying rubber composition (R1).

(Preparation of rubber-reinforced resin composition (S))
10 parts of the rubber composition for resin modification (R1) was dissolved in 90 parts of styrene monomer, and a styrene polymerization stock solution containing 300 ppm of n-dodecyl mercaptan (chain transfer agent) was prepared with respect to the solution.
Into a 4 liter jacketed reactor, 2,300 g of a styrene polymerization stock solution was placed and polymerized at 130 ° C. with sufficient stirring until the solid content concentration reached 45%.
A polymerization reaction liquid is taken out from the reactor, cooled to 20 ° C., 625 g thereof and 1,875 g of a 0.5% aqueous solution of polyvinyl alcohol (GOHSENOL GH-20, manufactured by Nippon Synthetic Chemical Industry) as a dispersing agent are mixed in a 4 liter stirring device. The mixture was placed in a stainless steel reactor equipped with a heater and heated to 70 ° C. with stirring.
Next, 1.25 g of benzoyl peroxide and 0.63 g of dicumyl peroxide were added as radical polymerization initiators, and the mixture was added at 70 ° C. for 1 hour, 90 ° C. for 1 hour, 110 ° C. for 1 hour, and further at 130 ° C. for 4 hours. Suspension polymerization was carried out while raising the temperature step by step. After completion of the polymerization, the mixture was cooled to 20 ° C., the polymer was separated by filtration, the polymer was recovered, and washed with water. After dehydration, it was dried under reduced pressure at 60 ° C. for 12 hours to obtain a polystyrene resin composition as a rubber-reinforced resin composition (S1).
The resulting rubber-reinforced resin composition (S1) was evaluated for gloss, color tone and fish eye. The results are shown in Table 1.

(Preparation of MBS resin (M))
Also, a solution consisting of 50 g of the resin modifying rubber composition (R), 320 g of styrene, 62 g of methyl methacrylate and 10 g of ethylbenzene was prepared in a 10 liter autoclave. To this, 0.1 g of n-dodecyl mercaptan and 0.02 g of t-butyl peroxybenzoate were added, and polymerization was started at 120 ° C. with stirring at 300 rpm. After 2 hours, the temperature was raised to 135 ° C. and the reaction was continued for 1 hour. Thereafter, the temperature was further raised to 150 ° C., the reaction was continued for 1 hour, and finally the reaction was continued until the temperature was raised to 200 ° C. and the polymerization conversion rate became approximately 100%. While keeping the reaction solution at 200 ° C., volatile components were removed under reduced pressure of 50 mmHg to obtain MBS resin (M1).
The transparency of the obtained MBS resin composition (M1) was evaluated. The results are shown in Table 1.

(Example 2)
The amount of tetra (tridecyl) -4,4′-butylidenebis (2-tert-butyl-5-methylphenyl) diphosphite was changed to 0.09 parts and 4,6-bis (octylthiomethyl) -o-cresol The amount was changed to 0.05 part, and 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate [acrylate compound heat stabilizer] A rubber composition R2 for resin modification was obtained in the same manner as in Example 1 except that 04 parts was used in combination.
Table 1 shows the results of the evaluation of the properties of this resin-modifying rubber composition (R2).
Using this resin-modifying rubber composition (R2), a rubber-reinforced resin composition (S2) and an MBS resin (M2) were obtained in the same manner as in Example 1.
Table 1 shows the results of evaluating the properties of this rubber-reinforced resin composition (S2) and MBS resin (M2).

(Example 3)
To a solution of the conjugated diene polymer rubber (a1), 0.525 mol of benzoic acid (corresponding to 0.5 times equivalent of n-butyllithium used for polymerization) was added as a 5% solution of xylene, and 10% at 70 ° C. The mixture was stirred for a minute to obtain a solution of the neutralized conjugated diene polymer rubber (a2).
Rubber composition for resin modification (R3) in the same manner as in Example 2, except that a solution of neutralized conjugated diene polymer rubber (a2) is used instead of the solution of conjugated diene polymer rubber (a1). Got.
Table 1 shows the results of the evaluation of each characteristic of this resin-modifying rubber composition (R3).
Using this resin-modifying rubber composition (R3), a rubber-reinforced resin composition (S3) and an MBS resin (M3) were obtained in the same manner as in Example 1.
Table 1 shows the results of evaluating the properties of this rubber-reinforced resin composition (S3) and MBS resin (M3).

Example 4
The amount of tetra (tridecyl) -4,4′-butylidenebis (2-tert-butyl-5-methylphenyl) diphosphite was changed to 0.05 parts and 4,6-bis (octylthiomethyl) -o-cresol 0 Example 1 except that 0.12 part of 2-t-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate was used instead of 0.09 part In the same manner as described above, a rubber composition for resin modification (R4) was obtained.
Table 1 shows the results of the evaluation of the properties of this resin-modifying rubber composition (R4).
Using this resin-modifying rubber composition (R4), a rubber-reinforced resin composition (S4) and an MBS resin (M4) were obtained in the same manner as in Example 1.
Table 1 shows the results of evaluating the properties of the rubber-reinforced resin composition (S4) and the MBS resin (M4).

(Example 5)
Instead of the solution of the conjugated diene polymer rubber (a1), a solution of the conjugated diene polymer rubber (b) is used, and tetra (tridecyl) -4,4′-butylidenebis (2-t-butyl-5-methylphenyl) is used. ) Resin modification was carried out in the same manner as in Example 1, except that the amount of diphosphite was changed to 0.08 parts and the amount of 4,6-bis (octylthiomethyl) -o-cresol was changed to 0.04 parts. A quality rubber composition (R5) was obtained.
Table 1 shows the results of the evaluation of the properties of this resin-modifying rubber composition (R5).
Using this resin-modifying rubber composition (R5), a rubber-reinforced resin composition (S5) and an MBS resin (M5) were obtained in the same manner as in Example 1.
Table 1 shows the results of evaluating the properties of this rubber-reinforced resin composition (S5) and MBS resin (M5).

(Comparative Example 1)
Instead of tetra (tridecyl) -4,4′-butylidenebis (2-t-butyl-5-methylphenyl) diphosphite, the thermal stabilizer Tris (2,4- Di-t-butylphenyl) phosphite was used instead of 0.09 part of 4,6-bis (octylthiomethyl) -o-cresol, octadecyl-3- (3,5- A rubber composition for resin modification (RC1) was obtained in the same manner as in Example 1 except that 0.10 parts of di-t-butyl-4-hydroxyphenyl) propionate was used.
Table 2 shows the results of the evaluation of the properties of this resin-modifying rubber composition (RC1).
Using this rubber composition for resin modification (RC1), a rubber-reinforced resin composition (SC1) and an MBS resin (MC1) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC1) and MBS resin (MC1).

(Comparative Example 2)
To the solution of the conjugated diene polymer rubber (a1), 1.05 mol of benzoic acid (corresponding to 1.0 times the equivalent of n-butyllithium used in the polymerization) was added as a 5% solution of xylene and 10% at 70 ° C. The mixture was stirred for a minute to obtain a solution of the neutralized conjugated diene polymer rubber (a3).
A rubber composition for resin modification (RC2) in the same manner as in Comparative Example 1 except that a solution of the neutralized conjugated diene polymer rubber (a3) is used instead of the solution of the conjugated diene polymer rubber (a1). Got.
Table 2 shows the results of the evaluation of the properties of this resin-modifying rubber composition (RC2).
Using this resin-modifying rubber composition (RC2), a rubber-reinforced resin composition (SC2) and an MBS resin (MC2) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC2) and MBS resin (MC2).

(Comparative Example 3)
Instead of the solution of conjugated diene polymer rubber (a1), a solution of neutralized conjugated diene polymer rubber (a3) was used, and the thermal stabilizer was changed to tetra (tridecyl) -4,4′-butylidenebis (2-t From the combination of 0.10 parts of -butyl-5-methylphenyl) diphosphite and 0.09 part of 4,6-bis (octylthiomethyl) -o-cresol, 4,6-bis (octylthiomethyl) -o-cresol A rubber composition for resin modification (RC3) was obtained in the same manner as in Example 1 except that only 0.20 part was changed.
Table 2 shows the results of evaluating the properties of this resin-modifying rubber composition (RC3).
Using this resin-modifying rubber composition (RC3), a rubber-reinforced resin composition (SC3) and an MBS resin (MC3) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC3) and MBS resin (MC3).

(Comparative Example 4)
Instead of the solution of the conjugated diene polymer rubber (a1), a solution of the neutralized conjugated diene polymer rubber (a2) is used, and the thermal stabilizer is tetra (tridecyl) -4,4′-butylidenebis (2-t- 0.09 part of butyl-5-methylphenyl) diphosphite, 0.05 part of 4,6-bis (octylthiomethyl) -o-cresol and 2-t-butyl-6- (3-t-butyl- 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate 0.04 parts of octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) which is a phenol compound heat stabilizer Rubber for resin modification in the same manner as in Example 3, except that 0.10 parts of propionate and 0.20 parts of 4,6-bis (octylthiomethyl) -o-cresol are used. A composition (RC4) was obtained.
Table 2 shows the results of the evaluation of the properties of this resin-modifying rubber composition (RC4).
Using this resin-modifying rubber composition (RC4), a rubber-reinforced resin composition (SC4) and an MBS resin (MC4) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC4) and MBS resin (MC4).

(Comparative Example 5)
Instead of tetra (tridecyl) -4,4′-butylidenebis (2-t-butyl-5-methylphenyl) diphosphite, the thermal stabilizer Tris (2,4- Resin modification in the same manner as in Example 1 except that di-t-butylphenyl) phosphite was used and the amount of 4,6-bis (octylthiomethyl) -o-cresol was increased to 0.20 parts. A rubber composition (RC5) was obtained.
Table 2 shows the results of the evaluation of the properties of this resin-modifying rubber composition (RC5).
Using this resin-modifying rubber composition (RC5), a rubber-reinforced resin composition (SC5) and an MBS resin (MC5) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC5) and MBS resin (MC5).

(Comparative Example 6)
Instead of the solution of the conjugated diene polymer rubber (a1), the solution of the conjugated diene polymer rubber (b) is used, and the thermal stabilizer is octadecyl-3- (3,5-di-t which is a phenol compound thermal stabilizer. A rubber composition for resin modification (RC6) was obtained in the same manner as in Example 1 except that the amount was changed to 0.08 part of (butyl-4-hydroxyphenyl) propionate.
Table 2 shows the results of the evaluation of each characteristic of this resin-modifying rubber composition (RC6).
Using this resin-modifying rubber composition (RC6), a rubber-reinforced resin composition (SC6) and an MBS resin (MC6) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of the rubber-reinforced resin composition (SC6) and MBS resin (MC6).

(Comparative Example 7)
Except that the solution of the conjugated diene polymer rubber (b) was used in place of the solution of the conjugated diene polymer rubber (a1) and the heat stabilizer was changed to only 0.50 parts of distearyl pentaerythritol diphosphite In the same manner as in Example 1, a rubber composition for resin modification (RC7) was obtained.
Table 2 shows the results of the evaluation of the properties of this resin-modifying rubber composition (RC7).
Using this resin-modifying rubber composition (RC7), a rubber-reinforced resin composition (SC6) and an MBS resin (MC7) were obtained in the same manner as in Example 1.
Table 2 shows the results of evaluating the properties of this rubber-reinforced resin composition (SC7) and MBS resin (MC7).

Notes to Table 1 and Table 2 * 1: Equivalent ratio of polymerization catalyst to metal * 2: Tetra (tridecyl) -4,4′-butylidenebis (2-t-butyl-5-methylphenyl) diphosphite * 3: Distearyl penta Erythritol diphosphite * 4: 4,6-bis (octylthiomethyl) -o-cresol * 5: 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4 -Methylphenyl acrylate * 6: Tris (2,4-di-t-butylphenyl) phosphite * 7: Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate

From the results of Tables 1 and 2, the following can be understood.
Even if a phosphite compound heat stabilizer having one phosphorus atom is used in combination with a phosphite compound heat stabilizer having two phosphorus atoms in the molecule, a resin modification obtained can be obtained. The quality rubber composition has a large amount of gel and is inferior in storage stability, and the rubber-reinforced resin composition obtained therefrom is inferior in various properties (Comparative Example 1). In the production process of the conjugated diene polymer rubber used for the resin-modifying rubber composition, the above properties are hardly improved even when the catalyst residue is neutralized with an acid (Comparative Example 2).
Even if a thioether compound heat stabilizer is used as a heat stabilizer, or a phenol compound heat stabilizer is used in combination with this, no improvement is seen, and the storage stability, polymerization stability, etc. are inferior, and the rubber composition for resin modification The color tone of the product and rubber-reinforced resin composition is inferior (Comparative Examples 3 and 4).
Even when a phosphite compound heat stabilizer having one phosphorus atom and a thioether compound heat stabilizer having a phenol group in the molecule are used in combination, the polymerization stability is not excellent, and the rubber composition for resin modification and rubber reinforcement The color tone of the resin composition is not so good (Comparative Example 5). Further, when only the phenol compound heat stabilizer is used, the storage stability of the resin-modifying rubber composition is inferior, and fish eyes are produced by molding the rubber-reinforced resin composition (Comparative Example 6).
In addition, when the phosphite compound thermal stabilizer which has a 2 or more phosphorus atom in a molecule | numerator is used in large quantities exceeding the range prescribed | regulated by this invention, each characteristic deteriorates on the contrary (comparative example 7).

  In contrast, at least one heat stabilizer selected from the group consisting of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, a thioether compound heat stabilizer, and an acrylate compound heat stabilizer is used as a conjugated diene. What was added in the range of 0.01-0.20 weight part with respect to 100 weight part of polymer rubber shows each outstanding characteristic (each Example). In particular, a combination of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, a thioether compound heat stabilizer, and an acrylate compound heat stabilizer exhibits excellent characteristics (Examples 2 and 3). ). Further, due to the synergistic effect of the combination of the neutralization treatment of the catalyst residue with acid and the heat stabilizer of the present invention in the production process of the conjugated diene polymer rubber (comparison between Example 2 and Example 3), particularly excellent characteristics. Is obtained.

Claims (18)

  Consists of 100 parts by weight of a conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, and a thioether compound heat stabilizer and an acrylate compound heat stabilizer. A rubber composition for resin modification comprising 0.01 to 0.20 parts by weight of at least one heat stabilizer selected from the group.   100 parts by weight of conjugated diene polymer rubber, 0.01 to 0.20 parts by weight of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule, and at least one thioether compound heat stabilizer and at least one acrylate A rubber composition for resin modification comprising a total of 0.01 to 0.20 parts by weight of a compound heat stabilizer.   The rubber composition for resin modification according to claim 1 or 2, wherein the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is a diphosphite heat stabilizer.   The amount of the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is 0.02 to 0.10 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. The rubber composition for resin modification according to any one of Items.   The amount of the phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is 0.03 to 0.09 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. The rubber composition for resin modification according to any one of Items.   The rubber composition for resin modification according to any one of claims 1 to 5, wherein the thioether compound heat stabilizer has two or more thioether structures in its molecule.   The rubber composition for resin modification according to any one of claims 1 to 6, wherein the thioether compound heat stabilizer has a phenol group in its molecule.   The rubber for resin modification according to any one of claims 1 to 7, wherein the amount of the thioether compound heat stabilizer is 0.01 to 0.10 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. Composition.   The rubber for resin modification according to any one of claims 1 to 8, wherein the amount of the thioether compound heat stabilizer is 0.02 to 0.09 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. Composition.   The rubber composition for resin modification according to any one of claims 1 to 9, wherein the acrylate compound heat stabilizer has a phenol group in its molecule.   The resin-modifying rubber according to any one of claims 1 to 10, wherein the amount of the acrylate compound heat stabilizer is 0.01 to 0.10 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. Composition.   The rubber for resin modification according to any one of claims 1 to 11, wherein the amount of the acrylate compound heat stabilizer is 0.02 to 0.09 parts by weight per 100 parts by weight of the conjugated diene polymer rubber. Composition.   The phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule is added to the conjugated diene polymer rubber, and then the other heat stabilizer is added. The manufacturing method of the rubber composition for resin modification in any one.   The conjugated diene polymer rubber obtained by using an organolithium compound as a polymerization initiator is selected from the group consisting of an organic acid, an inorganic acid and a Lewis acid in an amount of less than 1 equivalent to lithium of the organolithium compound. The resin modification according to claim 13, which comprises adding at least one acid and then adding a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule to the conjugated diene polymer rubber. A method for producing a quality rubber composition.   Claims wherein at least the addition of a phosphite compound heat stabilizer having two or more phosphorus atoms in the molecule to the conjugated diene polymer rubber is performed before the compounding agent other than the heat stabilizer is added to the conjugated diene polymer rubber. 15. A method for producing a rubber composition for resin modification as set forth in claim 13 or 14.   16. The rubber composition for resin modification according to claim 15, wherein all of the heat stabilizer is added to the conjugated diene polymer rubber before adding a compounding agent other than the heat stabilizer to the conjugated diene polymer rubber. Manufacturing method.   A rubber-reinforced resin composition comprising the rubber composition for resin modification according to any one of claims 1 to 12 and a base resin.   The rubber-reinforced resin composition according to claim 17, wherein the base resin contains at least an aromatic vinyl resin.