JPH0366326B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a block copolymer comprising a vinyl aromatic compound and a conjugated diene, or a mixture of the block copolymer and a thermoplastic resin, with at least one selected from unsaturated carboxylic acids and derivatives thereof. This invention relates to a method for modifying a polymer using one type of modifier. [Prior Art] Many attempts have been made to improve adhesiveness, green strength, etc. by modifying resins or rubbers with highly functional unsaturated carboxylic acid compounds, such as maleic acid compounds. For example, Japanese Patent Application Publication No. 1973-
No. 56427 suggests a method of maleating a block copolymer of butadiene and styrene in the coexistence of a rubber developing oil by generating radicals using a radical initiator or heating. Also, Tokukai Akira
No. 55-13720 and JP-A No. 55-25315 disclose a method of mylenizing a block copolymer of butadiene and styrene in an organic solvent in the presence of a radical polymerization medium. Furthermore, JP-A-52-
No. 123443 also suggests a method of maleating a block copolymer consisting of butadiene and styrene together with polyethylene in a screw type extruder in the presence of a radical initiator. [Problems to be Solved by the Invention] However, in both of these methods, maleation occurs under the generation of radicals, so gelation of the resulting modified block copolymer is unavoidable. The modified block copolymer results in a significant deterioration in properties as a thermoplastic rubber, such as melt flow characteristics and appearance characteristics. Under these circumstances, the inventor of the present invention has conducted extensive research to solve the above problems, and has found that when a modification reaction is carried out under specific reaction conditions in the absence of a radical initiator using a screw extruder, the melting properties It has been discovered that a modified polymer with excellent properties and a small amount of toluene insoluble matter can be obtained, and this has already been disclosed in JP-A-55-38803 and JP-A-55-60511. however,
The modified block copolymers obtained by the methods disclosed in these publications did not necessarily have good color tone and needed to be improved. [Means and effects for explaining the problem] Under the present circumstances, the present inventors have investigated a method for obtaining a modified polymer that has excellent color tone and melting properties and contains less gel-like substances, and has developed a method for obtaining a modified polymer with a specific phenolic compound. It was discovered that by using a specific amount of a specific sulfur-based compound, effects that could not be predicted from conventional antioxidants can be exhibited, leading to the present invention. That is, the present invention has at least one polymer segment mainly composed of vinyl aromatic hydrocarbon and at least one polymer segment mainly composed of conjugated diene, and the vinyl aromatic hydrocarbon content is 5 to 5. 95
At least one modifier selected from unsaturated carboxylic acids and derivatives thereof is added to a block copolymer or a mixture of the block copolymer and a thermoplastic resin or rubbery polymer at 180 to 320°C. When reacting at a temperature of 0.05 to 5 parts by weight of at least one phenolic compound represented by the following general formulas [] to [], 0.05 to 5 parts by weight per 100 parts by weight of the block copolymer or mixture. The present invention relates to the modification of a polymer, characterized in that the modification reaction is carried out in the presence of at least one sulfur-based compound represented by the following general formulas [] and [] in Part 1. (In the above formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is an alkenyl group having 2 to 4 carbon atoms, and R ₃ is a tert
-Butyl group or cyclohexyl group, R ₄ is hydrogen or an alkyl group having 1 to 18 carbon atoms, R ₅ is 3 to 18 carbon atoms
20 alkyl groups, R ₆ and R ₇ are hydrogen or carbon number 1
~6 alkyl group is shown. ) The present invention will be explained in detail below. The block copolymer used in the present invention comprises at least one, preferably two or more polymer segments mainly composed of vinyl aromatic hydrocarbons and at least one polymer segment mainly composed of conjugated dienes. and the content of vinyl aromatic hydrocarbons is 5 to 5.
95% by weight, preferably 10 to 90% by weight, more preferably 15 to 85% by weight. Such a block copolymer exhibits properties as a thermoplastic elastomer when the content of vinyl aromatic hydrocarbons is 60% by weight or less, preferably 55% by weight or less; %, preferably 65% by weight or more, exhibits properties as a thermoplastic resin. Any known method may be used for producing the block copolymer used in the present invention, for example, Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-17979, Japanese Patent Publication No. 45-31951, Japanese Patent Publication No. 46 Examples include the method described in Publication No.-32415. These are methods in which a conjugated diene and a vinyl aromatic hydrocarbon are block copolymerized using a polymerization initiator _such as an organolithium compound in a hydrocarbon solvent. A) _o , B(-A-B) _o (In the above formula, A is a polymer segment mainly composed of vinyl aromatic hydrocarbon, and B is a polymer segment mainly composed of conjugated diene.A segment The _boundary between _the
(A-B) _o )]- _n+1 X [(B-A) _o B)]- _n+1 X, [
(A-B) _o A)]- _n+1 X (In the above formula, A and B are the same as above, and
represents, for example, the residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, or epoxidized soybean oil, or the residue of an initiator such as a polyfunctional organolithium compound. m and n are integers of 1 or more. ) It is obtained as a block copolymer represented by:
In the above formula, the polymer block mainly composed of vinyl aromatic hydrocarbons refers to
A copolymer block of a vinyl aromatic hydrocarbon and a conjugated diene containing 50% by weight or more and/or a vinyl aromatic hydrocarbon homopolymer block is defined as a polymer block mainly containing a conjugated diene. A copolymer block of a conjugated diene and a vinyl aromatic hydrocarbon containing an amount exceeding % by weight and/or
Or a conjugated diene homopolymer block. The vinyl aromatic hydrocarbons in the copolymer block may be uniformly distributed or tapered. A plurality of uniformly distributed portions and/or tapered distributed portions may coexist in each block. The block copolymer used in the present invention may be any mixture of block copolymers represented by the above general formula. The conjugated diene used in the present invention is a diolefin having a pair of conjugated double bonds, such as 1,
3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-
Examples include butadiene, 1,3-pentadiene, 1,3-hexadiene, and particularly common ones include 1,3-butadiene and isoprene. These may be used not only alone, but also as a mixture of two or more. Vinyl aromatic hydrocarbons used in the present invention include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, etc. However, styrene is a particularly common one. These may be used not only alone, but also as a mixture of two or more. The number average molecular weight of the block copolymer used in the present invention is 10,000 to 800,000, preferably 30,000 to 500,000.
It is. Incidentally, the block copolymer used in the present invention may be hydrogenated. In the present invention, the mixture of the block copolymer and the thermoplastic resin or rubbery polymer can be modified. Examples of thermoplastic resins include polystyrene, impact-resistant rubber-modified styrene polymer, acrylonitrile-styrene copolymer, and styrene-
50% polystyrene resins such as maleic anhydride copolymer, acrylonitrile-butadiene-styrene copolymer, methacrylate ester-butadiene-styrene copolymer, polyethylene, and ethylene.
Copolymers of ethylene containing the above and other monomers copolymerizable with it, such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers and their hydrolysates, ethylene-acrylic acid ionomers, and chlorinated polyethylene Polyethylene resins such as polypropylene, copolymers of propylene containing 50% or more of propylene and monomers copolymerizable with it, such as propylene-ethylene copolymers, propylene-ethyl acrylate copolymers, and chlorinated polypropylene Polypropylene resins such as polybutene-1, polybutene resins that are copolymers of butene-1 and other monomers copolymerizable with it, polyvinyl chloride, polyvinylidene chloride, vinyl chloride and/or vinylidene chloride. 50%
Polyvinyl chloride resin which is a copolymer of vinyl chloride and/or vinylidene chloride containing the above and other monomers copolymerizable with it, vinyl acetate with a vinyl acetate content of 50% or more and other copolymers. Polyvinyl acetate resins that are copolymers with polymer monomers and their hydrolysates, acrylic acid and its esters and amides, methacrylic acid and its esters and amides, and these acrylic acid monomers.
Polyacrylate resins that are copolymers with other copolymerizable monomers containing 50% or more, polymers of acrylonitrile and/or methacrylonitrile, and other copolymers containing 50% or more of these acrylonitrile monomers Nitrile resins, which are copolymers with monomers such as
Constituent units of polyamide resins and polymers, such as ring-opening polymers of aminolaurolactam, condensation polymers of ε-aminoundecanoic acid, and condensation polymers of hesamethylene diamine and dibasic acids such as adipic acid and sepacic acid. are linked by repeated ester bonds, such as condensates of dibasic acids such as phthalic acid and isophthalic acid, or derivatives thereof, and glycol components such as ethylene glycol, propylene glycol, butylene glycol, etc. Certain polyester resins, paryphenylene ether resins, or grafted polyphenylene ether resins obtained by graft polymerizing vinyl-substituted aromatic hydrocarbons to these resins, polyphenylene sulfide resins, polyoxymethylene, trioxane, and alkylene oxides. Polyacetal resins such as copolymers of
4'-dihydroxydiphenylalkane, 4,4'-
Polycarbonate resins such as polymers obtained by the reaction of dihydroxy compounds such as dihydroxy diphenyl sulfide and phosgene, or polymers obtained by transesterification of the dihydroxy compounds and dipheniccarbonate, polyether sulfones, etc. , polysulfone resins such as polyallylsulfone, thermoplastic polyurethane resins obtained by polyaddition reaction of diisocyanate components and glycol components, polybutadiene resins such as trans polybutadiene and 1,2-polybutadiene, pisphenol A and phthalate. Polyarylate resin, which is a polycondensation polymer consisting of an acid component, fluorine resin, which has a structure in which part or all of the hydrogen in a chain hydrocarbon polymer compound is replaced with fluorine, polyoxybenzoyl resin, polyimide resin Such as resin. In addition, as the rubbery polymer, polybutadiene,
Polyisoprene, styrene-butadiene copolymer, butadiene-acrylonitrile copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer,
Examples include thermoplastic polyurethane elastomer, silicone rubber, epichlorohydrin rubber, acrylic rubber, ethylene-vinyl acetate copolymer fluoro rubber, and the like. In the present invention, the mixing ratio (weight ratio) of the block copolymer and the thermoplastic resin or rubbery polymer is generally 99/1 to 3/97, preferably 97/97.
3-5/95. Incidentally, these may be mixed in advance or may be mixed in the modification reaction apparatus during the modification reaction. The modified mixture of the block copolymer and the thermoplastic resin or the rubbery elastic material has excellent compatibility with the unmodified thermoplastic resin or the rubbery elastic material, and at the same time, the block copolymer Higher temperature compared to single case, e.g. 200~
The modification reaction at 320°C, preferably 220 to 300°C can be carried out more smoothly. Examples of unsaturated carboxylic acids and their derivatives as modifiers used in the present invention include maleic acid, maleic anhydride, maleic ester, maleic amide, maleic imide, fumaric acid, fumaric ester, fumaric amide, fumaric acid imide, itaconic acid, itaconic anhydride, itaconic acid ester,
itaconic acid amide, itaconic acid imide, halogenated maleic acid, halogenated maleic anhydride, halogenated maleic acid ester, halogenated maleic acid amide, halogenated maleic acid imide, cis-
4-cyclohexene-1,2-dicarboxylic acid, cis-4-cyclohexene-1,2-dicarboxylic acid anhydride, cis-4-cyclohexene-1,2-dicarboxylic acid ester, cis-4-cyclohexene-
1,2-dicarboxylic acid amide, cis-4-cyclohexene-1,2-dicarboxylic acid imide, endo-cis-bicyclo(2,2,1)-5-heptene-2,3-dicarboxylic acid, endo-cis anhydride -bicyclo(2,2,1)-5-heptene-2,3-
Dicarboxylic acid, endo-cis-bicyclo(2,
2,1)-5-heptene-2,3-dicarboxylic acid ester, endo-cis-bicyclo(2,2,
1) -5-heptene-2,3-dicarboxylic acid amide, endo-cis-bicyclo(2,2,1)-5
Examples include -heptene-2,3-dicarboxylic imide, acrylic acid, acrylic ester, acrylic amide, methacrylic acid, methacrylic ester, and methacrylic amide. These can be used not only alone but also as a mixture of two or more. Among these, unsaturated dicarboxylic acids or derivatives thereof are preferred, and maleic anhydride is particularly preferred. In the present invention, the amount of at least one modifier selected from unsaturated carboxylic acids and derivatives thereof is generally 0.1 to 100 parts by weight, preferably 0.5 parts by weight, per 100 parts by weight of the block copolymer or mixture.
~50 parts by weight. If the amount of modifier is too small, the modification effect will be small, and conversely, if the amount of modifier is too much, it will be difficult to remove unreacted modifier from the modified product, or the homopolymer of the modifier itself will be Undesirable due to mixing. In the present invention, the temperature at which the modifier is reacted with the block copolymer or the mixture is 180 to 320°C.
℃, preferably 200-280℃. The reaction temperature is
If the temperature is lower than 180°C, the reaction of the modifier will be low and the modification effect will be small, which is not preferable. On the other hand, the reaction temperature
If the temperature exceeds 320°C, the color tone and melting characteristics will deteriorate, and gel-like substances that are insoluble in solvents such as toluene will increase, which is not preferable. In the present invention, in order to suppress the formation of gel-like substances during the denaturation reaction,
Although it is preferable to carry out the modification reaction in the absence of a radical initiator such as a peroxide or an azo compound, it is preferable to carry out the modification reaction using a small amount of the radical initiator as long as it does not cause significant formation of gel-like substances. Operations such as increasing the reaction rate may also be performed. The greatest feature of the present invention is that 0.05 to 5 parts by weight per 100 parts by weight of the block copolymer or mixture;
Preferably 0.1 to 2 parts by weight of the general formula [],
[], at least one selected from the phenolic compounds represented by [], 0.05 to 5 parts by weight, preferably 0.1 to 2 parts by weight of the general formula [], []
The modification reaction is carried out in the presence of at least one kind selected from the sulfur-based compounds shown below.
If the amount of phenol-based compounds and sulfur-based compounds used is less than 0.05 parts by weight each, no effect on improving color tone or melting properties or suppressing the formation of gel-like substances will be observed; Effects beyond the scope of the present invention cannot be achieved. In the phenolic compounds represented by the general formulas [] to [], the substituent R ₁ represents an alkyl group having 1 to 4 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isobutyl group, a tert- Although a butyl group is mentioned, a methyl group or a tert-butyl group is particularly preferred. R ₂ is an alkenyl group having 2 to 4 carbon atoms, specifically, an ethenyl group, an isopropenyl group, a propenyl group, an isobutenyl group, a butenyl group, and the like. Particularly preferred is the ethenyl group. _R3
Preferred is tert-butyl group. Substituent R ₄
Specific examples include hydrogen, methyl group, ethyl group, propyl group, and bityl group, with hydrogen or methyl group being particularly preferred. Also, the general formula [],
In the sulfur-based compound represented by [ ], R ₅ represents an alkyl group having 3 to 20 carbon atoms, and specific examples include hexyl, octyl, dodecyl, and octadecyl groups, with dodecyl being particularly preferred. R ₆ and R ₇ are hydrogen atoms or have 1 to 18 carbon atoms
represents an alkyl group, with hydrogen, methyl, ethyl, propyl, and butyl groups being particularly preferred. In the present invention, the color tone and melting characteristics are even better,
In addition, since the mixture of gel-like substances further obtains a modified polymer, at least one of other phenol stabilizers, other sulfur stabilizers, phosphorus stabilizers, and amine stabilizers,
One type can be used in combination. Preferred specific examples thereof include (A) tetrakis[methylene-3-(3',5'-di-
tert-butyl-4'-hydroxyphenyl)propionate]methane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene,
2,4-bis-(n-octylthio)-6-(4
-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol-bis [3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,3,5-tris-(4-
At least one phenolic stabilizer selected from tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid and 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol) (B) Dilauryl-3,3'-thiodipropionic acid ester, dimyristyl-3,3'-thiodipropionic acid ester, distearyl-3,3'-thiodipropionic acid ester, laurylstearyl-3,3' - at least one sulfur stabilizer selected from thiodipropionic acid esters (C) tris(nonylphenyl) phosphorite;
Cyclic neopetanetetrirubis (octadecyl phosphite), tris(2,4-
di-tert-butylphenyl) phosphorite,
4,4'-Butyldene-bis(3-methyl-6-
tert-butylphenyl di-tridecyl) phosphite, 4,4'-biphenylene diphosphinate tetrakis (2,4-di-tert-butylphenyl), cyclic neopentanetetrayl bis(2,4-di-tert- At least one phosphorus stabilizer selected from (butylphinyl) phosphorite is mentioned. These are generally 0.05 to 5 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the block copolymer or mixture.
It can be used in combination within the range of 2 parts by weight. The method of the present invention is carried out in the substantial absence of organic solvents.
It is preferable to carry out the process while melt-kneading, but if necessary, the process may be carried out in a state where the mixture is melted in an organic solvent. Melt-kneading methods include methods using general mixers such as internal mixers, co-kneaders, continuous kneaders with twin-screw rotors, single-screw, twin-screw or multi-screw extruders, and in particular methods using extruders. The method is preferred for continuous production. In the melt kneading method using an extruder, the average residence time in the extruder is generally 10 to 1000
seconds, preferably 30 to 500 seconds. If the average retention time is too short, problems such as a low reaction rate or non-uniform reaction may occur, while if the average retention time is too long, the formation of gel-like substances will become noticeable, which is undesirable. . Furthermore, in the method of the present invention, the amount of unreacted modifier remaining in the modified polymer after the modification reaction is 1 part by weight or less, preferably 0.5 part by weight or less per 100 parts by weight of the modified polymer. is preferred in order to obtain a modified polymer with excellent color tone. For this purpose, a method is recommended in which the modification reaction is carried out using an extruder attached to a ventable device, and the unreacted modifier is removed from the pent part by means such as reduced pressure. In the method of the present invention, the modification reaction is carried out in the presence of a basic inorganic compound to obtain an ionic crosslinked modified polymer. Basic inorganic compounds are generally monovalent, divalent and trivalent metal compounds, such as sodium compounds, potassium compounds,
Examples include magnesium compounds, calcium compounds, zinc compounds, aluminum compounds, etc. Preferred examples of these metal compounds include hydroxides,
Includes alcoholates, carboxylates, and oxides. Of these, magnesium hydroxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, compounds based on these, and mixtures thereof can be suitably used. The amount of these added is 100% of the block copolymer or the mixture.
0.01 to 5 parts by weight per part by weight, preferably
It is 0.05 to 3 parts by weight. In addition to the above-mentioned thermoplastic polymers and rubbery polymers, the modified polymer obtained by the present invention includes reinforcing agents,
Fillers, antioxidants, ultraviolet absorbers, colorants,
It is possible to add pigments, aggregates, flame retardants, blowing agents and other additives. More specific examples of the above-mentioned additives that can be added to the modified polymer obtained in the present invention are described in "Handbook of Rubber and Plastic Compounding Chemicals," published by Rubber Digest Co., Ltd., 1974. [Effects of the Invention] The present invention not only provides an industrial production method for stably obtaining a polymer modified with an unsaturated carboxylic acid or its derivative, but also has excellent color tone and melt adhesive properties, and can be used as a gel material. A modified polymer with less mixture of The modified polymer obtained by the present invention takes advantage of the fact that it is modified with an unsaturated carboxylic acid or its derivative, and can be used as a modifying material for various thermoplastic resins and thermosetting resins, as a material for coverings, and as adhesives and adhesives. It can be used as a material for agents, asphalt modifying material, electric wire and cable material, vulcanized rubber modifying material, etc. [Examples] In order to explain the present invention in more detail, Examples are shown below, but these Examples are intended to demonstrate the excellent effects obtained by the present invention, and are not intended to demonstrate the excellent effects obtained by the present invention. It does not limit the scope. The block copolymers used in the examples of the present invention were produced as follows. [Block copolymer (A)] In a nitrogen gas atmosphere, n-butyllithium was added to an n-hexane solution containing 15 parts by weight of 1,3-butadiene and 20 parts by weight of styrene, and the mixture was heated at 70°C for 2 hours.
After polymerization for an hour, an n-hexane solution containing 45 parts by weight of 1,3-butadiene and 20 parts by weight of styrene was further added, and the mixture was polymerized at 70 DEG C. for 2 hours. The obtained polymer had a styrene content of 40% by weight and a B of MI(G) of 10g/10mm.
It was a block copolymer with a -A-B-A structure. [Block copolymer (B)] In a nitrogen gas atmosphere, n-butyllithium was added to a cyclohexane solution containing 30 parts by weight of styrene, and after polymerization at 70°C for 1 hour, 70 parts by weight of 1,3-butadiene was added. A cyclohexane solution containing the mixture was added and polymerization was carried out at 70°C for 2 hours. After that, tetrachlorodyrane was added to 1/4 mole of the n-butyllithium used to make the styrene content 40% by weight and MI(G)20.
A block copolymer of (A-B( _-4 Si structure) of Add n-butyllithium to 70℃
After polymerization for 1 hour, a cyclohexane solution containing 20 parts by weight of 1,3-butadiene and 50 parts by weight of styrene was added and polymerization was carried out at 70°C for 2 hours. The obtained polymer was a block copolymer having an ABA structure with a styrene content of 80% by weight and an MI(G) of 8 g/10 mm. Examples 1 to 9 and Comparative Examples 1 to 6 After blending 100 parts by weight of block copolymer (A), 2 parts by weight of maleic anhydride, and the stabilizers shown in Table 1, the mixture was fed to a 30 mmφ extruder. The maleation reaction was carried out at 240°C. The average residence time in the extruder is approximately
It was hot in 90 seconds. Unreacted maleic anhydride was removed under reduced pressure from a vent installed near the tip of the extruder, so that the amount of residual maleic anhydride in the modified polymer was 0.2% by weight or less. The amount of maleic anhydride added to the resulting modified block copolymers varied from 0.4 to 0.6% by weight. Table 1 also shows the melt viscosity retention, toluene insoluble content, and color tone of the modified block copolymer obtained. It can be seen that the modified block copolymer subjected to the modification reaction in the presence of the phenolic compound and sulfur compound specified in the present invention has excellent color tone and melt viscosity characteristics, and contains less toluene-insoluble gel-like substances. In Example 1, when the operation of removing unreacted maleic anhydride from the vent part was not performed, the b value of the obtained modified polymer pellets was 35 and the color tone was slightly inferior.

【table】

【table】

[Table] Comparative Example 7 A modification reaction was carried out in the same manner as in Example 1 except that 0.5 parts by weight of phenothiazine was used instead of the phenol compound. The melt viscosity retention and toluene insoluble content of the obtained modified block copolymer were both good (rank ◎), and the color tone was at the rank △ level. When the above modified block copolymer was exposed to sunlight for one week, the color changed to reddish brown and the color tone was poor (rank x).
The modified block copolymers of Examples 1 to 9 showed almost no discoloration under the same sunlight exposure conditions. Comparative Example 8 When the modification reaction of Example 1 was carried out at 330°C,
Gelation occurred during the denaturation reaction, making it impossible to carry out the denaturation reaction smoothly. Examples 10 to 27 After blending 5 parts by weight of maleic anhydride and stabilizers with 100 parts by weight of a mixture of block copolymer and thermoplastic resin or rubbery polymer according to the compounding method shown in Table 2. The mixture was fed to a 30 mmφ extruder whose cylinder temperature was set to the temperature shown in Table 2, and a maleation reaction was carried out. The average residence time in the extruder was adjusted to a range of 60 to 120 seconds. In addition, unreacted maleic anhydride was removed under reduced pressure from the pent section attached to the tip of the extruder, and the amount of residual maleic anhydride in the modified polymer was reduced to 0.3% by weight.
I made it look like the following. The amount of maleic anhydride added to the obtained modified block copolymer was 0.2 to 1.5% by weight.
In addition, the melt viscosity of the modified block copolymer obtained using stabilizers outside the scope of the present invention was significantly superior, and the color tone was also good and it was gel-like. There was also little insoluble matter mixed in.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A polymer having at least one polymer segment mainly composed of a vinyl aromatic hydrocarbon and at least one polymer segment mainly composed of a conjugated diene, and having a vinyl aromatic hydrocarbon content of 5 At least one modifier selected from unsaturated carboxylic acids and derivatives thereof is added to a block copolymer or a mixture of the block copolymer and a thermoplastic resin or rubbery polymer in an amount of 180 to 95% by weight. When reacting at a temperature of 320°C, 100% of the block copolymer or the mixture
The following general formula [] ~ 0.05 to 5 parts by weight per part by weight
When the modification reaction is carried out in the presence of at least one selected from the phenolic compounds represented by [] and 0.05 to 5 parts by weight of at least one selected from the sulfur compounds represented by the following general formula [], [] A method for modifying polymers characterized by: (In the above formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₂ is an alkenyl group having 2 to 4 carbon atoms, and R ₃ is a tert
-Butyl group or cyclohexyl group, R ₄ is hydrogen or an alkyl group having 1 to 18 carbon atoms, R ₅ is 3 to 18 carbon atoms
20 alkyl groups, R ₆ and R ₇ are hydrogen or carbon number 1
~6 alkyl group is shown. )