JP2005112949A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition which is improved in impact resistance without losing such characteristics of a polyacetal resin as slidability and so on. <P>SOLUTION: The thermoplastic resin composition contains a polyacetal resin (A) and an impact strength-modifying agent (B) having as the main component a graft rubber copolymer (G) which is a product of graft-polymerization by using at least one kind of an emulsifier (E) selected from a sulfonic acid-based salt compound and a sulfate-based salt compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin composition containing a polyacetal resin, and particularly to a thermoplastic resin composition having improved impact resistance without impairing the original properties of the polyacetal resin such as excellent sliding properties. It is.

  Polyacetal resin is an engineering plastic excellent in mechanical strength, fatigue resistance, slidability, chemical resistance, etc., and is used in OA equipment, information equipment, home appliances, automobiles, clothing, stationery, sundries, building materials, etc. It is widely used as a material for resin gears and mechanism parts. In particular, in addition to the above characteristics, mass production is possible at a low cost, and therefore, it is widely used as a material for buttons, clips, and gears that require the above characteristics.

When used as a material for buttons, clips, and gears, performance such as high impact resistance, low noise, low wear, and high accuracy is required. In particular, it is important to have excellent impact resistance.
Here, as a means for improving impact resistance, it is conceivable to add reinforcing fillers such as inorganic fillers such as glass fiber, carbon fiber, potassium titanate whisker, calcium carbonate, and talc to the polyacetal resin. . However, the reinforcing filler is generally harder than the polyacetal resin, and the reinforcing filler may scrape the polyacetal resin during sliding, leading to an increase in the amount of wear.
In addition, homopolymers and copolymers exist in polyacetal resins, and homopolymers tend to have higher impact resistance than copolymers. However, the homopolymer has a large post-shrinkage accompanying the progress of crystallization, and therefore has poor dimensional stability and is not suitable for the exemplified applications.
In addition, Patent Documents 1 and 2 propose examples of improving impact resistance in consideration of plating use, clip characteristics, and the like, but further improvement in impact resistance is required.
JP-A-2-129266 JP-A-6-1000075

  An object of this invention is to provide the thermoplastic resin composition which improved the impact resistance, without impairing the characteristics, such as a slidability which polyacetal resin originally has.

The present inventors have found that the above problems can be solved by blending a specific impact strength modifier, and have completed the present invention.
That is, the thermoplastic resin composition of the present invention is a graft rubber obtained by graft polymerization using a polyacetal resin (A) and at least one emulsifier (E) selected from a sulfonic acid salt compound and a sulfate salt compound. It contains the impact strength modifier (B) which has a copolymer (G) as a main component, It is characterized by the above-mentioned.
In the present specification, the “main component” means a component having a content of 60% by mass or more.

As a suitable graft rubber copolymer (G),
(A) mass median particle size _{(d w)} is 80 to 300 nm, and the weight average of the particle diameter _{(d w)} to the number average particle diameter _{(d n)} ratio _(d w / d _n) is 2 or less In the presence of a latex containing a butadiene rubber polymer (R), a total of 80 to 100 parts by weight of a methacrylic acid ester and an aromatic vinyl compound, and 0 to 20 parts by weight of a vinyl monomer copolymerizable therewith (However, the total amount of these graft monomers is 100 parts by mass) and 0.5 to 10 parts by mass of the emulsifier (E) (however, the total amount of the graft monomers and the butadiene rubber polymer (R) The total amount is 100 parts by mass), a graft rubber copolymer (GX) obtained by graft polymerization,
(B) an acrylic rubber (P) component containing n-butyl acrylate as a constituent component;
An acrylic rubber (Q) component comprising a (meth) acrylic acid ester of an alcohol having a branched side chain or an alcohol having an alkyl group having 13 or more carbon atoms as a constituent component and having a glass transition temperature lower than that of the acrylic rubber (P) component; A graft rubber copolymer (GY) containing
(C) Silicone / acrylic composite rubber obtained by graft polymerization of at least one vinyl monomer in the presence of composite rubber (X) latex containing polyorganosiloxane and polyalkyl (meth) acrylate rubber A graft rubber copolymer (GZ) having a polyorganosiloxane content of 8 to 70% by mass and a composite rubber (X) content of 65 to 90% by mass is mentioned.

As the emulsifier (E), a sulfonic acid salt compound having two phenyl groups is particularly preferable.
The graft rubber copolymer (G) is preferably one obtained by coagulating a polymer latex obtained after graft polymerization using an alkaline earth metal compound as a coagulant (F). As the coagulant (F), calcium acetate or calcium chloride is particularly suitable.
Moreover, it is preferable that the aluminum ion amount contained in an impact strength modifier (B) is 35 ppm or less.

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin composition which improved impact resistance can be provided, without impairing the characteristics, such as slidability which polyacetal resin originally has.

Hereinafter, the present invention will be described in detail.
The thermoplastic resin composition of this invention mix | blends a specific impact strength modifier (B) with the polyacetal resin (A).

"Polyacetal resin (A)"
The polyacetal resin (A) is not particularly limited, but a resin mainly composed of a polyoxymethylene copolymer having an oxymethylene group as a main repeating unit and an oxyalkylene group having 2 or more carbon atoms is preferable.
Specifically, formaldehyde or trioxane, which is a cyclic oligomer thereof, is used as a main monomer, and ethylene oxide, propylene oxide, 1,3-dioxolane, 1,3,5-trioxepane, 1,4-butanediol formal, diethylene glycol formal, etc. What is obtained by copolymerizing in the presence of a cationic catalyst using at least one selected from cyclic ethers and / or cyclic acetals having at least one carbon-carbon bond as a comonomer is preferable. As the comonomer, 1,3-dioxolane and / or 1,3,5-trioxepane, which do not cause chain transfer in the polymer, is preferable because of good comonomer dispersibility.

  As a polyoxymethylene copolymer, a copolymer containing an oxyalkylene group having 2 or more carbon atoms is suitable as a comonomer, but the content of oxyalkylene group units is 0.5 to 3.0% by mass. It is preferable that it is 0.6 to 2.0% by mass, and 0.7 to 1.6% by mass is particularly preferable. If the comonomer content is too low, the stability of the copolymer to heat and chemicals may be insufficient, and the long-term durability of various properties such as strength and accuracy may be reduced. If the comonomer content is too high, strength and rigidity may be reduced. Tends to decrease, which is not preferable.

The polyoxymethylene copolymer can be produced by the same equipment and method as the conventionally known trioxane copolymerization method.
In the production of the polyoxymethylene copolymer, batch production, continuous production, any production method may be employed, and any polymerization method such as melt polymerization, solution bulk polymerization, etc. may be employed. In consideration of industrial productivity, a continuous bulk polymerization method using a liquid monomer as a raw material and obtaining a solid powdery bulk polymer as the polymerization proceeds in the presence of an inert liquid catalyst as necessary is preferable.

At the time of polymerization, a chain transfer agent can be added to adjust the molecular weight of the polyoxymethylene copolymer. Examples of the chain transfer agent include methylal, ethylal, butyral and the like. Although the addition amount of a chain transfer agent is not specifically limited, It is suitably adjusted within the range of 0-1000 ppm according to the molecular weight of a copolymer.
As the polymerization catalyst, a known cationically active catalyst can be used. Cationic active catalysts include Lewis acids, in particular halides such as boron, tin, titanium, phosphorus, arsenic and antimony, such as boron trifluoride, tin tetrachloride, titanium tetrachloride, phosphorus pentachloride, phosphorus pentafluoride, Compounds such as arsenic pentafluoride and antimony pentafluoride and their complex compounds or salts, protic acids such as trifluoromethanesulfonic acid, perchloric acid, esters of protic acids, especially esters of perchloric acid and lower aliphatic alcohols (for example (Tertiary butyl ester of perchloric acid), protonic acid anhydrides, especially mixed anhydrides of perchloric acid and lower aliphatic carboxylic acids (especially acetyl perchlorite), or isopolyacids, heteropolyacids (eg phosphomolybdic acid), Or triethyloxonium hexafluorophosphate, triphenylmethyl hex Fluoro Aruze diisocyanate, acetyl hexafluoro borate and the like. Among these, boron trifluoride and a coordination compound of boron trifluoride and an organic compound (for example, ethers) are preferable. The addition amount of these catalysts is generally 10 to 300 ppm with respect to the total amount of the main monomer and comonomer.

Although it does not specifically limit as a superposition | polymerization apparatus, The continuous superposition | polymerization apparatus of trioxane, such as a kneader, a twin screw type continuous extrusion mixer, and a twin screw paddle type continuous mixer, can be used. If the apparatus to be used is a closed system, it may be divided into two or more stages. However, the thing provided with the grinding | pulverization function in which the solid polymer produced | generated by a polymerization reaction is obtained with a fine form is preferable.
The polymerization temperature is not particularly limited, but is generally from 64 to 120 ° C. A relatively low temperature is preferable within this range.
The preferred range of the polymerization time varies depending on the amount of the catalyst and is not particularly limited, but is generally 0.5 to 100 minutes.
After a suitable polymerization time has elapsed, it is preferable to deactivate the polymerization catalyst by immediately bringing the deactivator into mixed contact with the crude polymer discharged from the polymerization apparatus. Examples of the quencher include a solution obtained by mixing an amine such as triethylamine or triethanolamine with an inorganic alkaline substance such as sodium fluoride or potassium fluoride. The deactivator used is preferably an aqueous solution.

  After the polyacetal resin (A) has deactivated the polymerization catalyst, it is subjected to washing, separation / recovery of unreacted monomers, drying, etc., if necessary, and terminal stability such as decomposition and removal of unstable terminal parts as necessary. It is melt-kneaded pellets through commercialization process, and further, through addition of additives such as various stabilizers and processability improvers as necessary, and commercialized.

  Examples of organic compounds suitable as a stabilizer and a processability improver include 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 1,6-hexanediol-bis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [3- ( 3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene N-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) propionate, 4,4′-methylenebis (2 6-di-tert-butylphenol), 4,4′-butylidenebis- (6-tert-butyl-3-methylphenol), 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy) -5-methylphenyl) propionyloxy] -1,1-dimethylethyl} 2,4,8,10-tetraoxaspiro [5,5] undecane, di-stearyl-3,5-di-t-butyl-4 -Hydroxybenzylphosphonate, 2-t-butyl-6- (3-t-butyl-5-methyl-2-hydroxybenzyl) -4-methylphenyl acrylate, N, N'-hexamethylenebis (3,5-di Antioxidants typified by hindered phenols such as (t-butyl-4-hydroxy-hydrocinnamamide), nylon 6,10, nylon 6,66,610, polyacrylic Substituents with higher fatty acids such as stearic acid such as sodium, potassium, magnesium, calcium, barium, and other substituents such as hydroxyl groups such as polycondensates with polyamides such as polyamide, melamine, dicyandiamide and formaldehyde Heat-resistant stabilizers typified by metal-containing compounds such as salts of higher fatty acids, benzotriazoles such as 2- [2-hydroxy-3,5-bis- (α, α′-dimethylbenzyl) phenyl] benzotriazole, UV absorbers represented by benzophenones such as 2-hydroxy-4-methoxybenzophenone, 4-acetoxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl) -4-piperidyl) light stabilizer represented by hindered amines such as adipate, glycerin Examples include higher fatty acid esters such as monostearate and pentaerythritol tristearate, lubricants represented by higher fatty acid amides such as ethylenebis (stearylamide), and plasticizers such as polyethylene glycol and polyoxyethylene polypropylene copolymers. It is done. These may be used alone or in combination of two or more.

  Among them, as the antioxidant, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [3- (3,5-di-t- Butyl-4-hydroxyphenyl) propionate], 3,9-bis- {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) furopionyloxy-] 1,1-dimethylethyl } Hindered phenols such as -2,4,8,10-tetraoxaspiro [5,5] undecane are preferred, and the nitrogen-containing compound is preferably polycondensation with melamine, dicyandiamide or the like and formaldehyde, and a metal-containing compound As salts thereof, magnesium and calcium higher fatty acids and salts of substituted higher fatty acids are preferred.

  The total amount of the compound added as a stabilizer to the polyacetal resin (A) is not particularly limited, but is preferably 0.1 to 2.0% by mass, particularly 0.1 to 1.0% by mass. preferable.

"Impact strength modifier (B)"
In the present invention, the impact strength modifier (B) is a graft rubber copolymer (G) graft-polymerized using at least one emulsifier (E) selected from sulfonic acid salt compounds and sulfate salt compounds. ) As a main component.
Here, examples of the sulfonic acid salt compound include sodium dodecylbenzenesulfonate, sodium alkyldiphenyl ether disulfonate, and the like. Among them, a phenyl group-containing compound such as alkylbenzene sulfonate is preferable, and a compound containing two phenyl groups such as sodium alkyldiphenyl ether disulfonate is particularly preferable. Examples of the sulfuric acid salt compound include sodium lauryl sulfate. These emulsifiers (E) may be used individually by 1 type, and may use 2 or more types together. By using such an emulsifier (E), it is possible to improve impact resistance and thermal stability.
Although the usage-amount of an emulsifier (E) is not specifically limited, 0.5-10 mass parts is preferable with respect to 100 mass parts of total amounts of a graft monomer and a trunk polymer.
In the polymerization of the graft rubber copolymer (G), an emulsifying dispersant may be used in combination for the purpose of improving the polymerization stability. Examples of the emulsifying dispersant include sodium salt of β-naphthalenesulfonic acid formalin condensate.

 In addition, the graft rubber copolymer (G) is collected by spray recovery or salting out after the graft polymerization. As the graft rubber copolymer (G), a polymer latex obtained after the graft polymerization is used. Those obtained by coagulation using a coagulant (F) are preferred. As the coagulant (F), an alkaline earth metal compound such as magnesium chloride, magnesium acetate, barium chloride, barium acetate, calcium acetate, calcium chloride is preferable, and calcium acetate or calcium chloride is particularly preferable. By using such a graft rubber copolymer (G), a further effect of improving impact resistance and thermal stability can be obtained.

 In the present invention, the amount of aluminum ions detected from the impact strength modifier (B) is preferably 35 ppm, and more preferably 20 ppm or less. This is because aluminum ions may decompose the matrix resin. If it is within the above range, it is considered that there is almost no influence. The method for measuring the amount of aluminum ions will be described in the “Examples” section.

<Preferred example of graft rubber copolymer (G)>
Hereinafter, suitable examples of the graft rubber copolymer (G) will be described.
{Graft rubber copolymer (GX)}
As the graft rubber copolymer (G) suitable for the present invention,
(A) mass median particle size _{(d w)} is 80 to 300 nm, and the weight average of the particle diameter _{(d w)} to the number average particle diameter _{(d n)} ratio _(d w / d _n) is 2 or less In the presence of a latex containing a butadiene rubber polymer (R), a total of 80 to 100 parts by weight of a methacrylic acid ester and an aromatic vinyl compound, and 0 to 20 parts by weight of a vinyl monomer copolymerizable therewith (However, the total amount of these graft monomers is 100 parts by mass) and 0.5 to 10 parts by mass of the emulsifier (E) (however, the total amount of the graft monomers and the butadiene rubber polymer (R) The total amount is 100 parts by mass.), And a graft rubber copolymer (GX) obtained by graft polymerization.

As the butadiene-based rubber polymer (R), a homopolymer or copolymer of 1,3-butadiene is particularly preferable. Such a butadiene rubber polymer (R) comprises 1,3-butadiene, if necessary, a crosslinkable monomer, and one or more vinyl monomers copolymerizable with 1,3-butadiene. It is obtained by polymerizing.
Examples of the crosslinkable monomer include aromatic polyfunctional vinyl compounds such as divinylbenzene and divinyltoluene; dicarboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate and 1,3-butanediol diacrylate; trimethacrylic acid Examples include esters; triacrylic acid esters; carboxylic acid allyl esters such as allyl acrylate and allyl methacrylate; and di- or triallyl compounds such as diallyl phthalate, diallyl sebacate, and triallyl triazine. Examples of vinyl monomers that can be copolymerized with 1,3-butadiene (excluding crosslinkable monomers; the same applies hereinafter) include aromatic vinyl such as styrene and α-methylstyrene; methyl methacrylate, ethyl methacrylate Methacrylic acid alkyl ester such as ethyl acrylate, n-butyl acrylate, etc. acrylic acid alkyl ester, acrylonitrile, methacrylonitrile, etc. unsaturated nitrile, methyl vinyl ether, butyl vinyl ether etc. vinyl ether, vinyl chloride, vinyl bromide etc. halogen Vinyl chloride; vinylidene halides such as vinylidene chloride and vinylidene bromide; glycidyl group-containing vinyl monomers such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and ethylene glycol glycidyl ether That. These crosslinking monomers and vinyl monomers may be used alone or in combination of two or more.

  The compounding amount of each component is not particularly limited, but when the total amount of monomers used for the polymerization of the butadiene-based rubber polymer (R) is 100 parts by mass, the amount of 1,3-butadiene is 65 to 100 parts by mass, and the crosslinkability. The monomer amount is preferably 0 to 10 parts by mass, and the remainder is preferably one or more vinyl monomers that can be copolymerized with 1,3-butadiene. By setting the amount of 1,3-butadiene to 65 parts by mass or more, a good impact resistance imparting effect can be obtained. Moreover, what is necessary is just to add a crosslinkable monomer according to the level of the stress whitening resistance required, but 10 mass parts or less are preferable from a viewpoint of an impact resistance provision effect.

As a method for producing a latex of the butadiene rubber polymer (R), an emulsion polymerization method is suitable. In the emulsion polymerization, various known emulsifiers can be used as appropriate, and it is particularly preferable to use a sulfonic acid salt compound and / or a sulfate salt compound. The polymerization temperature is generally about 40 to 80 ° C., although it depends on the type of polymerization initiator. Further, before starting the polymerization, for example, a seed latex containing styrene or the like may be charged in advance.
The emulsion polymerization is preferably performed in multiple stages. Specifically, a method in which a part of the monomer used for the polymerization is previously charged in the reaction system and the remaining monomer is added all at once, dividedly or continuously after the polymerization is started is particularly preferable. In adopting multi-stage emulsion polymerization, the composition of the monomer charged initially and the composition of the monomer added later may be the same or may be changed. By adopting such a polymerization method, good polymerization stability can be obtained, and a latex having a desired particle size and particle size distribution can be stably obtained. Moreover, if a latex obtained by such a polymerization method is used to produce a graft rubber copolymer (GX) and blended with the polyacetal resin (A), the impact resistance, fluidity, and molding appearance are extremely high. An excellent resin composition is obtained.

As described above, the butadiene-based rubber polymer (R) has a mass average particle diameter (d _w ) of 80 to 300 nm, and a mass average particle diameter (d _w ) and a number average particle diameter (d _n ) the ratio _d w / _{d n} of is 2 or less.
If the mass average particle diameter (d _w ) is less than 80 nm, the impact resistance imparting effect may be reduced, and if it exceeds 300 nm, the stress whitening resistance and transparency may be deteriorated. Further, in the d w _/ d _n is greater than 2, with the impact resistance imparting effect is small, stress whitening resistance, transparency deteriorates, which may adversely affect against further shaped appearance.
The mass average particle diameter _{(d w)} and _d w / _{d n} of the butadiene-based rubber polymer (R) can be measured by a known method. For example, it can be measured using a commercially available capillary particle size distribution meter.

  The content of the butadiene rubber polymer (R) in the polymer latex used for the graft polymerization is preferably 50 to 85% by mass. If the content is less than 50% by mass, the impact resistance may be lowered, and if it exceeds 85% by mass, the dispersibility in the matrix resin may be lowered and the recovery as a powder may be difficult.

  The graft rubber copolymer (GX) is a vinyl-based copolymer that can be copolymerized with a total of 80 to 100 parts by weight of a methacrylic acid ester and an aromatic vinyl compound in the presence of the above-mentioned butadiene-based rubber polymer (R) latex. It is obtained by graft polymerization of 0 to 20 parts by mass of the monomer (however, the total amount of these graft monomers is 100 parts by mass), and then powder recovery by spray recovery or salting out. As the methacrylic acid ester used as the graft monomer, methacrylic acid alkyl ester is particularly preferable. When the monomer is used, the affinity with the matrix resin can be increased and good powder can be recovered.

  As the graft polymerization method, single-stage polymerization or multistage polymerization of two or more stages can be applied. When employing multistage polymerization, it is particularly preferable to prepare a part of the monomer used for the polymerization in the reaction system in advance and then add the remaining monomers all at once, divided addition or continuous addition after the start of the polymerization. By adopting such a polymerization method, good polymerization stability can be obtained, and a latex having a desired particle size distribution can be stably obtained.

As described above, it is preferable to use at least a methacrylic acid ester and an aromatic vinyl compound as a graft monomer, and further use other copolymerizable vinyl monomers as necessary.
Specific examples of the methacrylic acid ester include methyl methacrylate and ethyl methacrylate.
Specific examples of the aromatic vinyl compound include styrene, α-methylstyrene, halogen-substituted styrene, alkyl-substituted styrene and the like.
Specific examples of other copolymerizable vinyl monomers include acrylic acid alkyl esters such as ethyl acrylate and n-butyl acrylate; unsaturated nitriles such as acrylonitrile and methacrylonitrile; glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. Examples thereof include glycidyl group-containing vinyl monomers. Moreover, the various crosslinkable monomers illustrated previously as a suitable monomer used for manufacture of a butadiene-type rubber polymer (R) can also be used together. These vinyl monomers may be used alone or in combination of two or more.

  The blending ratio of the graft monomer is not particularly limited, but from the viewpoint of impact strength, transparency and fluidity, when the total amount of the graft monomer is 100 parts by mass, 10 to 99 parts by mass of the methacrylic acid ester and aromatic vinyl compound It is preferable to set it as 1-70 mass parts and 0-20 mass parts of other vinyl monomers which can be copolymerized.

From the same viewpoint, it is preferable to graft polymerize a mixture of these monomers in three stages.
For example, when three-stage graft polymerization is carried out, the first stage graft polymerization is carried out by using a methacrylic acid alkyl ester alone, or a single monomer comprising a methacrylic acid alkyl ester and one or more other vinyl monomers copolymerizable therewith. A monomer composed of an aromatic vinyl compound, or an aromatic vinyl compound and one or more other vinyl monomers copolymerizable with the aromatic vinyl compound. The third stage graft polymerization is carried out using a mixture of a methacrylic acid alkyl ester alone or a monomer mixture comprising a methacrylic acid alkyl ester and one or more other vinyl monomers copolymerizable therewith. It is particularly preferable to use this method.

By adopting such a polymerization method, for example, the impact-imparting effect and the compatibility with the polyacetal resin can be improved by the first stage graft polymerization, and the graft rubber copolymer ( The fluidity and transparency of GX) can be improved, and the gloss of the molding surface of the thermoplastic resin composition can be improved by the third stage graft polymerization.
When such polymerization method is employed, the total amount of the first stage graft monomer is 15 to 50 parts by mass, the total amount of the second stage graft monomer is 40 to 60 parts by mass, and the total amount of the third stage graft monomer is 5 to 45 parts by mass. (However, the total amount of graft monomers is 100 parts by mass). Setting the total amount of the first stage graft monomer to 15 parts by mass or more is preferable from the viewpoint of impact resistance of the thermoplastic resin composition, and setting it to 50 parts by mass or less, such as molding appearance of the thermoplastic resin composition, etc. This is preferable. Setting the total amount of the second stage graft monomer to 40 parts by mass or more is preferable from the viewpoint of fluidity of the graft rubber copolymer (GX), and setting to 60 parts by mass or less is the resistance of the thermoplastic resin composition. It is preferable in terms of impact properties and the like. Setting the total amount of the third stage graft monomer to 5 parts by mass or more is preferable from the viewpoint of the gloss of the molding surface of the thermoplastic resin composition, and setting to 45 parts by mass or less is that of the graft rubber copolymer (GX). It is preferable in terms of fluidity.

The blending ratio of the total amount of graft monomers and the butadiene-based rubber polymer (R), which is a trunk polymer, is not particularly limited, but when the total amount of graft monomers and the butadiene-based rubber polymer (R) is 100 parts by mass, butadiene The amount of the rubber-based rubber polymer (R) is preferably 50 to 80 parts by mass, and the total amount of graft monomers is preferably 50 to 20 parts by mass.
A total amount of the graft monomer of 50 parts by mass or less is preferable in terms of impact resistance and the like. Moreover, when this is 20 mass parts or more, it becomes difficult to generate | occur | produce a lump at the time of graft polymerization, and it is preferable at the point of moldability. At the same time, it is preferable from the viewpoint of fluidity of the graft rubber copolymer (GX), and a resin composition having a good molded appearance can be obtained.

  In the graft polymerization, various polymerization initiators can be used as necessary. Examples of the polymerization initiator include persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, lauroyl peroxide, diisopropylbenzene hydroperoxide, and the like. Organic peroxides; azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile; the above compounds and sulfites, hydrogen sulfites, thiosulfates, first metal salts, sodium formaldehyde sulfoxylate, dextst Examples include redox initiators combined with rose and the like.

{Graft rubber copolymer (GY)}
As the graft rubber copolymer (G),
(B) an acrylic rubber (P) component containing n-butyl acrylate as a constituent, and a (meth) acrylic acid ester of an alcohol having a branched side chain or an alcohol having an alkyl group having 13 or more carbon atoms, as constituents; A graft rubber copolymer (GY) containing an acrylic rubber (Q) component having a glass transition temperature lower than that of the acrylic rubber (P) component is also suitable.
This copolymer (GY) is a composite rubber containing at least two kinds of acrylic rubber components ((P) component and (Q) component) having different glass transition temperatures (hereinafter referred to as “polyalkyl (meth) acrylate type”). It is obtained by graft polymerization of at least one vinyl monomer (Ag) on a composite rubber (PQ).

Each acrylic rubber component is obtained by polymerizing a monomer containing one or more alkyl (meth) acrylates.
The alkyl (meth) acrylate is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, ethoxyethyl acrylate, methoxytripropylene glycol acrylate, 4-hydroxybutyl acrylate, Examples include lauryl methacrylate and stearyl methacrylate. These alkyl (meth) acrylates may be used individually by 1 type, and may use 2 or more types together.

In the polymerization of the acrylic rubber component, a monomer having two or more unsaturated bonds in the molecule may be added to the monomer liquid in an amount of 20% by mass or less, preferably 0.1 to 18% by mass. . A monomer having two or more unsaturated bonds in the molecule acts as a crosslinking agent or graft crossing agent.
Suitable crosslinking agents include, for example, silicones such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, divinylbenzene, polyfunctional methacrylic group-modified silicones, and the like. is there. Further, as the graft crossing agent, for example, allyl methacrylate, triallyl cyanurate, triallyl isocyanurate and the like are suitable. Allyl methacrylate can also be used as a crosslinking agent. These crosslinking agents and graft crossing agents may be used alone or in combination of two or more.
In the polymerization of the acrylic rubber component, the monomer liquid is further mixed with a copolymer component, such as an aromatic alkenyl compound such as styrene, α-methylstyrene, and vinyl toluene; a vinyl cyanide compound such as acrylonitrile and methacrylonitrile; a methacrylic acid-modified silicone. Various vinyl monomers such as fluorine-containing vinyl compounds may be added within a range of 30% by mass or less.

The polyalkyl (meth) acrylate composite rubber (PQ) contains at least two kinds of acrylic rubber components ((P) component and (Q) component), and these acrylic rubber components each have a glass transition temperature. Different ones are used.
Here, the polyalkyl (meth) acrylate composite rubber (PQ) preferably has two or more glass transition temperatures at 10 ° C. or lower, and at least one glass transition temperature is an n-butyl acrylate homopolymer. It is preferably lower than the glass transition temperature.
The glass transition temperature of the n-butyl acrylate homopolymer varies depending on whether or not there is crosslinking. “To make at least one glass transition temperature lower than the glass transition temperature of the n-butyl acrylate homopolymer”, the acrylic rubber (Q) component has a glass transition temperature of acrylic rubber containing n-butyl acrylate ( It may be designed to be lower than the glass transition temperature of the component P) alone.
By using a polyalkyl (meth) acrylate composite rubber (PQ) having such a glass transition temperature, it is possible to enhance the impact resistance imparting effect of the resulting impact strength modifier, particularly the impact resistance imparting effect at low temperatures. it can.

The glass transition temperature of the polymer is measured as a Tan δ transition point measured by a dynamic mechanical property analyzer (hereinafter referred to as “DMA”). In general, a polymer obtained from a monomer has an inherent glass transition temperature, and a single transition point is observed by itself (single component or multiple component random copolymer), but a mixture of multiple components, Alternatively, a unique transition point is observed in each of the composite polymers.
For example, in a polymer composed of two components, two transition points are observed by measurement. That is, in a polymer composed of two components, two peaks corresponding to each transition point are usually observed in the Tan δ curve measured by DMA. When the composition ratio is biased or when the transition temperature is close, each peak may approach and may be observed as a peak with a shoulder portion. Unlike a single peak curve, it can be discriminated. That is, in the polyalkyl (meth) acrylate based composite rubber (PQ), the glass transition temperature derived from the acrylic rubber (Q) component is higher than the glass transition temperature derived from the acrylic rubber (P) component containing n-butyl acrylate. Will be observed low.

  The polyalkyl (meth) acrylate-based composite rubber (PQ) is not particularly limited as long as it satisfies the above characteristics, but an acrylic rubber (P) component containing n-butyl acrylate as a constituent component, 2-ethylhexyl acrylate, What consists of the acrylic rubber (Q) component which contains at least 1 sort (s) chosen from the group which consists of ethoxyethyl acrylate, methoxytripropylene glycol acrylate, 4-hydroxybutyl acrylate, lauryl methacrylate, stearyl methacrylate as the component is excellent It is preferable because the effect of imparting impact resistance is manifested. Particularly, when the acrylic rubber (Q) component contains at least one of 2-ethylhexyl acrylate, lauryl methacrylate, and stearyl methacrylate as a constituent component, impact resistance is improved. Effect, more preferable because particularly excellent impact resistance imparting effect at low temperatures. In addition, when using stearyl methacrylate etc. which have crystallinity near room temperature, it is preferable to use together the monomer which melt | dissolves this.

The production method of the polyalkyl (meth) acrylate composite rubber (PQ) is not particularly limited. For example, in the case of comprising two kinds of acrylic rubber components, a monomer containing at least one kind of alkyl (meth) acrylate is first used. To obtain a first acrylic rubber component latex, and then add and impregnate the monomer constituting the second acrylic rubber component into the acrylic rubber component latex, and then the presence of a radical polymerization initiator. The method of making it polymerize under is mentioned. According to this method, a latex of polyalkyl (meth) acrylate based composite rubber (PQ) in which two kinds of acrylic rubber components are combined is obtained as the polymerization proceeds.
In addition, it is possible to employ a method such as dropwise polymerization of the second rubber component in the presence of the first rubber component, or enlargement of the combined rubber component with an acid or salt.

  In particular, the acrylic rubber (Q) component containing at least one selected from the group consisting of 2-ethylhexyl acrylate, ethoxyethyl acrylate, methoxytripropylene glycol acrylate, 4-hydroxybutyl acrylate, lauryl methacrylate, and stearyl methacrylate as a constituent component In the presence, it is preferable to obtain a polyalkyl (meth) acrylate composite rubber (PQ) by polymerizing a monomer containing n-butyl acrylate constituting the acrylic rubber (P) component.

The polymerization method is not particularly limited, but usually emulsion polymerization is employed, and forced emulsion polymerization can be employed if necessary.
When the acrylic rubber (Q) component is polymerized, it is preferable to employ forced emulsion polymerization. For example, when 2-ethyl acrylate, lauryl methacrylate, or stearyl methacrylate is used as a monomer constituting the acrylic rubber (Q) component, these are poor in water solubility, so that the acrylic rubber (Q) component is obtained by forced emulsion polymerization. Is preferably polymerized.
As the emulsifier and dispersion stabilizer used in the emulsion polymerization, known surfactants such as anionic, nonionic, and cationic can be used. Moreover, although the mixture can also be used as needed, it is preferable to use in that case combining an emulsifier with a large micelle formation ability, and a small emulsifier.

The particle diameter of the polyalkyl (meth) acrylate composite rubber (PQ) is not particularly limited, but the mass average particle diameter is in the range of 100 nm to 800 μm in consideration of the impact resistance and molded appearance of the resulting resin composition. Is preferred. When the mass average particle diameter is less than 100 nm, the impact resistance of the resin composition is reduced, and when it exceeds 800 nm, the impact resistance of the resin composition is reduced and the molded appearance may be deteriorated.
A mass average particle diameter is calculated | required by measurement of mass distribution. The “mass distribution” is a distribution in which the mass ratio of particles within a minute interval between a certain particle diameter dp and dp + Δdp is expressed as a percentage. The method for measuring the “mass average particle diameter” of the polyalkyl (meth) acrylate composite rubber (PQ) in this specification will be described in the “Examples” section.

  The vinyl monomer (Ag) to be grafted onto the polyalkyl (meth) acrylate composite rubber (PQ) is not particularly limited, but is an aromatic alkenyl compound such as styrene, α-methylstyrene, vinyltoluene; methyl methacrylate, 2 -Methacrylic acid esters such as ethylhexyl methacrylate; Acrylic acid esters such as methyl acrylate, ethyl acrylate and n-butyl acrylate; Vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. These may be used alone or in combination of two or more.

  In the monomer liquid, if necessary, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate having two or more unsaturated bonds in the molecule, A crosslinking agent such as silicone such as divinylbenzene or polyfunctional methacrylic group-modified silicone, or a grafting agent such as allyl methacrylate, triallyl cyanurate, or triallyl isocyanurate may be added within a range of 20% by mass or less. it can.

The ratio of the polyalkyl (meth) acrylate composite rubber (PQ) and the vinyl monomer (Ag) in the acrylic rubber-based graft copolymer (GY) is preferably 60-99.9% by mass for the former and the latter for 40 to 0.1% by mass, more preferably the former is 70 to 99.9% by mass, the latter is 30 to 0.1% by mass, and still more preferably the former is 80 to 99.9% by mass, and the latter is It is 20-0.1 mass%, Most preferably, the former is 85-95 mass%, and the latter is 15-5 mass%.
If the vinyl monomer (Ag) is less than 0.1% by mass, the dispersibility of the resulting acrylic rubber-based graft copolymer (GY) in the resin is lowered, and a resin composition obtained by blending it is obtained. There are cases where the workability of the steel deteriorates. On the other hand, when it exceeds 40 mass%, the impact strength imparting effect of the acrylic rubber-based graft copolymer (GY) may be lowered.

  Further, the amount of the iron compound used in the production of the acrylic rubber-based graft copolymer (GY) is preferably 0.0015 ppm or less, and more preferably 0.0005 ppm or less. This has the meaning of suppressing decomposition of the matrix resin, and if it exceeds the above range, the matrix resin may be decomposed, which is not preferable. On the other hand, if it is less than 0.00005 ppm, the polymerizability deteriorates, which is not preferable.

{Graft rubber copolymer (GZ)}
As the graft rubber copolymer (G),
(C) obtained by graft polymerization of at least one vinyl monomer (Bg) in the presence of a composite rubber (X) latex containing a polyorganosiloxane (S) and a polyalkyl (meth) acrylate rubber A graft rubber copolymer having a polyorganosiloxane content of 8 to 70% by mass and a composite rubber (X) content of 65 to 90% by mass. GZ) is also suitable.

  Particularly, the silicone / acrylic composite rubber (X) has a structure in which 1 to 99% by mass of the polyorganosiloxane component and 99 to 1% by mass of the polyalkyl (meth) acrylate rubber component cannot be separated from each other, And the thing whose total amount of a polyorganosiloxane component and a polyalkyl (meth) acrylate rubber component is 100 mass% is suitable.

 Although it does not specifically limit as polyorganosiloxane (S), The polyorganosiloxane containing a vinyl polymerizable functional group is preferable. Such a polyorganosiloxane (S) is produced using dimethylcycloorganosiloxane, a siloxane containing a vinyl polymerizable functional group capable of binding to dimethylcycloorganosiloxane via a siloxane bond, and, if necessary, a siloxane-based crosslinking agent. Can do.

 Examples of dimethylcycloorganosiloxane include 3-membered or more diorganosiloxane-based cyclics, and those having 3 to 7 members are particularly preferable. Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. These may be used alone or in combination of two or more.

 The vinyl polymerizable functional group-containing siloxane is not particularly limited as long as it contains a vinyl polymerizable functional group and can be bonded to dimethylcycloorganosiloxane through a siloxane bond, but the reactivity with dimethylcycloorganosiloxane is not limited. In consideration, various alkoxysilane compounds containing a vinyl polymerizable functional group are preferable. Specifically, β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-methacryloyloxypropylethoxydiethoxymethylsilane and δ-methacryloyloxybutyldiethoxymethylsilane and other methacryloyloxysilane, tetramethyltetravinylcyclotetrasiloxane and other vinylsiloxanes, p-vinylphenyldimethoxymethylsilane and other vinylphenylsilanes And γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropyltrimethoxysilane, etc. Script siloxane and the like are suitable. In addition, vinyl-polymerizable functional group containing siloxane may be used individually by 1 type, and may use 2 or more types together.

 As the siloxane-based crosslinking agent, trifunctional or tetrafunctional silane-based crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane are preferably used.

  For example, polyorganosiloxane (S) is a high-speed latex obtained by emulsifying a mixture of dimethylcycloorganosiloxane and a vinyl-polymerizable functional group-containing siloxane or a mixture containing a siloxane-based crosslinking agent as necessary with an emulsifier and water. After homogenization using a homomixer that produces fine particles by the shearing force of rotation, or a homogenizer that produces fine particles by the jet output of a high-pressure generator, the polymer is polymerized at a high temperature using an acid catalyst, and then the acid is converted to an alkaline substance. This can be done by neutralization.

  Examples of the method for adding an acid catalyst include a method of mixing with a siloxane mixture, an emulsifier and water, and a method of dropping a latex in which a siloxane mixture is atomized into a high-temperature acid aqueous solution at a constant rate. The latter method is preferable in consideration of ease of control of the diameter. The method of mixing the siloxane mixture, emulsifier, water and / or acid catalyst includes high-speed stirring and mixing with a high-pressure emulsifier such as a homogenizer. Among them, the method using a homogenizer is polyorganosiloxane latex particles. It is preferable because the diameter distribution can be reduced.

As the emulsifier used in the production of the polyorganosiloxane (S), anionic emulsifiers such as sodium alkylbenzene sulfonate, sodium lauryl sulfate, sodium polyoxyethylene nonylphenyl ether sulfate are preferable. Of these, sodium alkylbenzene sulfonate and sodium lauryl sulfate are particularly preferred.
Examples of the acid catalyst include sulfonic acids such as aliphatic sulfonic acid, aliphatic substituted benzenesulfonic acid, and aliphatic substituted naphthalenesulfonic acid, and mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid. These acid catalysts may be used individually by 1 type, and may use 2 or more types together. Of these, aliphatic-substituted benzenesulfonic acid is preferable and n-dodecylbenzenesulfonic acid is particularly preferable because it is excellent in the stabilizing effect of the polyorganosiloxane latex. Further, when n-dodecylbenzenesulfonic acid and a mineral acid such as sulfuric acid are used in combination, it is possible to reduce the molding appearance defect of the resin composition due to the emulsifier component of the polyorganosiloxane latex, which is preferable.

  The polymerization of the polyorganosiloxane (S) can be stopped by cooling the reaction solution and further neutralizing the latex with an alkaline substance such as caustic soda, caustic potash or sodium carbonate.

The composite rubber (X) can be prepared by adding an alkyl (meth) acrylate component to the polyorganosiloxane (S) latex and polymerizing with a known radical polymerization initiator.
Examples of the method for adding the alkyl (meth) acrylate include a method in which the alkyl (meth) acrylate is mixed with the polyorganosiloxane latex and a method in which the alkyl (meth) acrylate is dropped into the polyorganosiloxane latex at a constant rate. However, considering the impact resistance of the resulting resin composition, the former method is preferred.

Examples of the alkyl (meth) acrylate include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, and alkyls such as hexyl methacrylate, 2-ethylhexyl methacrylate, and n-lauryl methacrylate. And methacrylate. Among these, n-butyl acrylate is particularly preferable in consideration of the impact resistance and molding gloss of the resin composition.
Examples of the alkyl (meth) acrylate include allyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, triallyl cyanurate, triallyl isocyania. Polyfunctional alkyl (meth) acrylates such as nurate can also be used.
Alkyl (meth) acrylate may be used individually by 1 type, and may use 2 or more types together.
As the radical polymerization initiator, a peroxide, an azo initiator, a redox initiator combined with an oxidizing agent / reducing agent, or the like is used. Among them, a redox initiator is preferable, and a system in which ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, Rongalite, and hydroperoxide are combined is particularly preferable.

  The graft rubber copolymer (GZ) is obtained, for example, by radical polymerization of at least one vinyl monomer in the presence of the composite rubber (X). It can be produced by adding a monomer and by one-stage or multi-stage radical polymerization. When employing multistage polymerization, a method is preferred in which a part of the monomer used for the polymerization is charged into the reaction system in advance, and after the polymerization is started, the remaining monomers are added all at once, dividedly or continuously. By adopting such a polymerization method, good polymerization stability can be obtained, and a latex having a desired particle size and particle size distribution can be stably obtained.

Although it does not specifically limit as a vinyl-type monomer, For example, methacrylic acid ester, methyl acrylate, ethyl acrylate, such as aromatic alkenyl compounds, such as styrene, (alpha) -methylstyrene, vinyltoluene, methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate And acrylic acid esters such as butyl acrylate, and vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. These monomers may be used individually by 1 type, and may use 2 or more types together.
As the radical polymerization initiator, those exemplified in the production of the composite rubber (X) (reaction between polyorganosiloxane and alkyl (meth) acrylate) can be used.
Further, various chain transfer agents and graft crossing agents for adjusting the molecular weight and graft ratio of the graft polymer can be added to the monomer solution used in the graft polymerization.

 Although the particle diameter of the graft rubber copolymer (GZ) is not particularly limited, it is preferable that the mass average particle diameter is in the range of 100 nm to 800 μm in consideration of the impact resistance and the molded appearance of the resin composition. If the average particle size is less than 100 nm, the impact resistance of the resin composition may be reduced, and if it exceeds 800 nm, the impact resistance of the resin composition may be lowered and the molded appearance may be deteriorated.

As described above, the content of the polyorganosiloxane (S) in the graft rubber copolymer (GZ) is 8 to 70% by mass. When the content of the polyorganosiloxane (S) is less than 8% by mass, a sufficient impact resistance imparting effect cannot be obtained, and when it exceeds 70% by mass, other excellent properties of the polyacetal resin may be impaired.
Moreover, as above-mentioned, content of the composite rubber (X) in a graft rubber copolymer (GZ) shall be 65-90 mass%. If the content of the composite rubber (X) is less than 65% by mass, sufficient impact resistance imparting effect cannot be obtained, and if it exceeds 90% by mass, other excellent properties of the polyacetal resin may be impaired.
Further, the amount of the iron compound used at the time of producing the composite rubber (X) is preferably 0.0015 ppm or less, and more preferably 0.0005 ppm or less. This has the meaning of suppressing decomposition of the matrix resin, and if it exceeds the above range, the matrix resin may be decomposed, which is not preferable. On the other hand, if it is less than 0.00005 ppm, the polymerizability deteriorates, which is not preferable.

"Thermoplastic resin composition"
Preparation of the thermoplastic resin composition of the present invention is not particularly limited as long as a predetermined amount of the impact strength modifier (B) can be blended with the polyacetal resin (A). A known method to be used can be appropriately selected. For example, the polyacetal resin (A) and the impact strength modifier (B) are mixed directly or in advance, and then kneaded with a single or twin screw extruder or the like, and pelletized to prepare a thermoplastic resin composition. be able to.
In addition, as a method for molding the thermoplastic resin composition, a method of molding pellets prepared in the target composition as described above is suitable, but after preparing a plurality of types of pellets having different compositions, It is also possible to employ a method of mixing (diluting) at a predetermined ratio and subjecting to molding, and obtaining the target composition after molding. In preparing the pellets, it is preferable to pulverize a part or all of the polyacetal resin (A) as a substrate in advance in order to improve the dispersibility of the components to be blended therein.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. “Part” and “%” represent “part by mass” and “% by mass”, respectively, unless otherwise specified.

“Production of impact strength modifier (Production Examples 1 to 7)”
(Production Example 1) Impact strength modifier (BX1)
(1) Manufacture of butadiene rubber polymer (R1) latex The following components as the first monomer were charged into a 70 L autoclave and then heated to 43 ° C. When the temperature reached 43 ° C., the following redox initiator was added. The reaction was started by addition. Thereafter, the temperature was further raised to 65 ° C.
First monomer:
1,3-butadiene 23.6 parts styrene 1.25 parts t-dodecyl mercaptan 0.15 parts p-menthane hydroperoxide 0.1 parts sodium pyrophosphate 0.5 parts sodium lauryl sulfate 0.11 parts deionized water 70 Part redox initiator:
Ferrous sulfate 0.003 parts Dextrose 0.3 parts Deionized water 5 parts Three hours after the start of polymerization, the following initiator was further added. Immediately thereafter, the following second monomer, emulsifier and deionized water were added. It dripped continuously over time.
Initiator:
p-Mentane hydroperoxide 0.2 part Second monomer:
1,3-butadiene 70.8 parts Styrene 3.75 parts t-dodecyl mercaptan 0.45 parts Emulsifier, deionized water:
Sodium lauryl sulfate 1.2 parts Deionized water 75 parts 21 hours after the start of polymerization, a butadiene rubber polymer (R1) latex was obtained. Mass-average particle diameter of the butadiene rubber polymer (R1) Latex _{(d w)} is 165 _nm, was _d w _/ d n = 1.2. The content of butadiene rubber polymer (R1) in the latex was 98.5% by mass.
(2) Production of impact strength modifier (BX1) The following components were charged into a nitrogen-substituted flask, and the internal temperature was maintained at 70 ° C.
Butadiene rubber polymer (R1) latex 75 parts (solid content)
Sodium lauryl sulfate 1.5 parts Sodium formaldehyde sulfoxylate 0.6 parts Next, a mixture of the following components was added dropwise over 1 hour, and then held for 1 hour. The amount of cumene hydroxy peroxide added was 0.3% with respect to 100% of the total amount of graft monomers.
Methyl methacrylate 95 parts Styrene 5 parts Cumene hydroxy peroxide After completion of the polymerization reaction, a graft copolymer (GX1) latex was obtained. To this latex, 2.5 parts of calcium acetate (however, the solid content of the latex is 100 parts) was added and coagulated to obtain an impact strength modifier (BX1).

(Production Example 2) Impact strength modifier (BX2)
(1) Production of butadiene rubber polymer (R2) latex The following components as the first monomer were charged into a 70 L autoclave and then heated to 43 ° C. When the temperature reached 43 ° C., the following redox initiator was added. The reaction was started by addition, and then the temperature was further raised to 65 ° C.
First monomer:
1,3-butadiene 31.1 parts Styrene 6.3 parts divinylbenzene 1.45 parts p-menthane hydroperoxide 0.1 parts sodium pyrophosphate 0.5 parts sodium lauryl sulfate 0.8 parts deionized water 70 parts redox System initiator:
Ferrous sulfate 0.003 parts Dextrose 0.3 parts Deionized water 5 parts The following initiator was further added 2 hours after the start of polymerization, and immediately after that, the following second monomer, emulsifier and deionized water 3 It dripped continuously over time.
Initiator:
p-Mentane hydroperoxide 0.2 part Second monomer:
1,3-butadiene 51.0 parts Styrene 12.8 parts Divinylbenzene 2.95 parts Emulsifier, deionized water:
Sodium lauryl sulfate 1.2 parts Deionized water 75 parts Reaction was performed for 7 hours from the start of polymerization to obtain a butadiene-based rubber polymer (R2) latex. Mass-average particle diameter of the butadiene rubber polymer (R2) Latex _{(d w)} is 90 _nm, it was _d w _/ d n = 1.2. The butadiene rubber polymer (R2) content in the latex was 99.0% by mass.
(2) Production of impact strength modifier (BX2) The following components were charged into a nitrogen-substituted flask, and the internal temperature was maintained at 70 ° C.
Butadiene rubber polymer (R2) latex 75 parts (solid content)
Sodium lauryl sulfate 1.5 parts Sodium formaldehyde sulfoxylate 0.6 parts Next, a mixture of the following components was added dropwise over 1 hour, and then held for 1 hour (first-stage graft polymerization). The amount of cumene hydroxy peroxide added was 0.3% with respect to the total amount of graft monomers.
Methyl methacrylate 6.25 parts Ethyl acrylate 1.25 parts Cumene hydroxy peroxide Further, a mixture of the following components was added dropwise over 1 hour, and then held for 3 hours (second stage graft polymerization). The amount of cumene hydroxy peroxide added was 0.3% with respect to the amount of graft monomer.
Styrene 12.5 parts cumene hydroxy peroxide Further, a mixture of the following components was added dropwise over 0.5 hours, and then held for 1 hour (third-stage graft polymerization). The amount of cumene hydroxy peroxide added was 0.3% with respect to the amount of graft monomer.
Methyl methacrylate 5 parts cumene hydroxy peroxide After completion of the polymerization reaction, a graft copolymer (GX2) latex was obtained. To this latex, 2.5 parts of calcium acetate (however, the solid content of the latex is 100 parts) was added and coagulated to obtain an impact strength modifier (BX2).

(Production Example 3) Impact strength modifier (BY1)
99.5 parts of 2-ethylhexyl acrylate and 0.2 parts of allyl methacrylate were mixed to obtain 100 parts of a (meth) acrylate monomer mixture.
Next, 100 parts of the above (meth) acrylate monomer mixture was added to 195 parts of distilled water in which 1 part of sodium alkyldiphenyl ether disulfonate (registered trademark Perex SS-H manufactured by Kao Corporation) was dissolved as a solid content. After pre-stirring at 10,000 rpm with a mixer, it was emulsified and dispersed with a homogenizer under a pressure of 300 kg / cm ² to obtain a (meth) acrylate emulsion.
This emulsion was transferred to a separable flask equipped with a condenser and a stirring blade. The temperature was raised while purging with nitrogen and mixing and stirring. When the temperature reached 50 ° C, 0.5 part of tert-butyl hydroperoxide was added. Thereafter, a mixed solution of 0.0002 part of ferrous sulfate, 0.0006 part of ethylenediaminetetraacetic acid disodium salt, 0.26 part of Rongalite and 5 parts of distilled water was added. Thereafter, it was left for 5 hours to complete the polymerization, and an acrylic rubber (Q1) latex was obtained.
The polymerization rate of the obtained acrylic rubber (Q1) latex was 99.9%. The latex was coagulated and dried with ethanol to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured to be 93.7%.
Furthermore, 7.0 parts of Perex SS-H as a solid content was added to the obtained latex. This latex was sampled so that the solid content of poly-2-ethylhexyl acrylate containing allyl methacrylate was 10 parts, placed in a separable flask equipped with a stirrer, and distilled so that the amount of distilled water in the system was 195 parts. Added water. At this point, PELEX SS-H is present in the latex in a solid content of 0.8 part.
Next, a mixed liquid of 78 parts of n-butyl acrylate containing 2.0% of allyl methacrylate constituting the acrylic rubber (P1) component and 0.32 part of tert-butyl hydroperoxide was charged and stirred for 10 minutes. Was permeated into the previously prepared acrylic rubber (Q1) particles. After further stirring for 10 minutes, the atmosphere was replaced with nitrogen, the temperature in the system was raised to 50 ° C., 0.002 part of ferrous sulfate, 0.006 part of ethylenediaminetetraacetic acid disodium salt, 0.26 part of Rongalite and distilled water. 5 parts of the mixed solution was charged to start radical polymerization. Thereafter, the inner temperature was maintained at 70 ° C. for 2 hours to complete the polymerization, and a polyalkyl (meth) acrylate composite rubber latex comprising an acrylic rubber (P1) component and an acrylic rubber (Q1) component was obtained.
A part of this latex was sampled and the particle size distribution of the polyalkyl (meth) acrylate composite rubber was measured (the method will be described later), and the mass average particle diameter was 0.2 μm. The latex was dried to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured and found to be 98.3%.
A liquid mixture of 0.06 part of tert-butyl hydroperoxide and 12 parts of methyl methacrylate was dropped into the obtained polyalkyl (meth) acrylate composite rubber latex at 70 ° C. over 15 minutes, and then at 70 ° C. for 4 hours. This was held, and the graft polymerization to the polyalkyl (meth) acrylate composite rubber was completed to obtain an acrylic rubber graft copolymer (GY1) latex. The polymerization rate of methyl methacrylate was 99.4%.
Furthermore, acrylic rubber graft copolymer (GY1) latex was dropped into 200 parts of hot water of calcium acetate 3.0%, coagulated, separated, washed and dried at 75 ° C. for 16 hours to improve the powdery impact strength. A quality agent (BY1) was obtained. Further, the glass transition temperature was measured (the method will be described later). In addition, the measured glass transition temperature is a value derived from a polyalkyl (meth) acrylate based composite rubber. The glass transition temperature was observed at −58 ° C. (derived from the (Q1) component) and −29 ° C. (derived from the (P1) component).
(Measurement method of particle size distribution and glass transition temperature)
-Particle size distribution measurement of polyalkyl (meth) acrylate based composite rubber A sample obtained by diluting the obtained latex with distilled water was used as a sample and measured using a CHDF2000 type particle size distribution meter manufactured by MATEC USA. The measurement conditions were standard conditions recommended by MATEC. That is, using a dedicated particle separation capillary cartridge and carrier liquid, the liquidity is almost neutral, the flow rate is 1.4 ml / min, the pressure is about 4000 psi, the temperature is 35 ° C., and the diluted latex sample has a concentration of about 3%. Measurements were made on 0.1 ml. As the standard particle size substance, a total of 12 monodispersed polystyrenes having a known particle size manufactured by DUKE Corporation in the range of 0.02 μm to 0.8 μm were used.
・ Measurement of glass transition temperature of acrylic rubber-based graft copolymer 70 parts of the obtained acrylic rubber-based graft copolymer (GY1) and 30 parts of polymethyl methacrylate (PMMA) were both measured using a 25φ single screw extruder at 250 ° C. Using a press machine set at 200 ° C., pelletized and prepared to a thickness of 3 mm, the plate was cut into a width of about 10 mm and a length of 12 mm, and measured with a TA Instruments DMA983 model at a temperature increase rate of 2 ° C./min. The temperature corresponding to the transition point of the obtained Tan δ curve was determined as the glass transition temperature.

(Production Example 4) Impact strength modifier (BY2)
0.2 parts by weight of 25 parts of 2-ethylhexyl acrylate, allyl methacrylate in an amount corresponding to 0.2% of 2-ethylhexyl acrylate, sodium alkyldiphenyl ether disulfonate (registered trademark Plex SS-H manufactured by Kao Corporation) as a solid content Part and 40 parts of water are pre-dispersed at 12000 rpm for 5 minutes with a TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd., and then forcibly emulsified under a pressure of 20 MPa with a homogenizer LB-40 manufactured by Gourin. Obtained.
A separable flask equipped with a condenser and a stirring blade is charged with 120 parts of the pre-emulsion and water, and an amount of tertiary butyl hydroperoxide corresponding to 0.5% of 2-ethylhexyl acrylate in the pre-emulsion is placed in the container. The inside of the container was replaced with a nitrogen stream at 200 ml / min for 50 minutes. Thereafter, the temperature was raised to 50 ° C., and a mixed solution of ferrous sulfate 0.00002 part, ethylenediaminetetraacetic acid disodium salt 0.0006 part, Rongalite 0.02 part and distilled water 5 part was added and held for 100 minutes. Thus, the first polymerization reaction was completed.
Next, the temperature of the system was adjusted to 60 ° C., and a pre-emulsion having the same composition as previously prepared was added all at once into the system, and sodium alkyldiphenyl ether disulfonate (registered trademark Plex SS-H manufactured by Kao Corporation) was added. ) As solids and 0.1 part of tertiary butyl peroxide in an amount corresponding to 0.5% of 2-ethylhexyl acrylate in the pre-emulsion charged this time, and the inside of the system is brought to 60 ° C. with stirring. Temperature was adjusted. Furthermore, a mixed solution of 0.02 parts of Rongalite and 5 parts of distilled water was added and held for 100 minutes to complete the second stage polymerization reaction to obtain an acrylic rubber (Q2) component.
Furthermore, the temperature in the system was adjusted to 55 ° C., 65 parts of n-butyl acrylate constituting the acrylic rubber (P2) component, allyl methacrylate in an amount corresponding to 0.5% of n-butyl acrylate, and n-butyl A mixture of isopropylbenzene peroxide in an amount corresponding to 0.5% of the acrylate was charged all at once in the system, held for 5 minutes, and a mixture of 0.1 part Rongalite and 10 parts distilled water was added. The third stage polymerization was started. Thereafter, the temperature was maintained at 65 ° C. for 100 minutes to complete the third stage polymerization reaction, and a rubbery polymer latex containing the components (P2) and (Q2) was obtained.
The polymerization rate of this rubbery polymer was 99.9%. The latex was dried to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured and found to be 96.7%. The glass transition temperature was measured by the same method as in Production Example 3. The glass transition temperature was observed at −58 ° C. (derived from the (Q2) component) and −30 ° C. (derived from the (P2) component).
With the temperature of this rubbery polymer latex maintained at 65 ° C., this corresponds to 14.5 parts of methyl methacrylate and 0.5 part of butyl acrylate, and 0.5% of the total amount of these two monomers. An amount of a mixture of isopropylbenzene peroxide was dropped into the system over 25 minutes. Thereafter, the polymerization was held for 150 minutes to complete the graft polymerization, and an acrylic rubber-based graft copolymer (GY2) latex was obtained.
This graft copolymer (GY2) latex was dropped into 200 parts of hot water in which 3.0% of calcium acetate was dissolved, solidified, separated, washed, dried at 75 ° C. for 16 hours, An impact strength modifier (BY2) was obtained.

(Production Example 5) Impact strength modifier (BZ1)
(1) Production of polyorganosiloxane (S1) latex 2 parts of tetraethoxysilane, 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane and 97.5 parts of octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane mixture. It was. 100 parts of the above siloxane mixture was added to 200 parts of distilled water in which 0.67 parts of sodium dodecylbenzenesulfonate and 0.67 parts of dodecylbenzenesulfonic acid were dissolved, and the mixture was pre-stirred at 10,000 rpm with a homomixer, and then under a pressure of 20 MPa with a homogenizer. And then emulsified and dispersed to obtain an organosiloxane latex. This mixed solution was transferred to a separable flask equipped with a condenser and a stirring blade, heated at 80 ° C. for 5 hours with mixing and stirring, and then allowed to stand at 20 ° C. After 48 hours, the pH of the latex was adjusted to 7. with an aqueous sodium hydroxide solution. 4 to complete the polymerization to obtain a polyorganosiloxane (S1) latex. The mass average particle diameter of the polyorganosiloxane was 170 nm.
(2) Production of Silicone / Acrylic Composite Rubber (X1) Latex 20 parts of the above polyorganosiloxane (S1) latex was sampled in terms of solid content, placed in a separable flask equipped with a stirrer, and 0.2 parts of sodium lauryl sulfate. (In terms of solid content) and 120 parts of distilled water were added, and after nitrogen substitution, the temperature was raised to 50 ° C., n-butyl acrylate 64.52 parts, allyl methacrylate 0.48 parts and tert-butyl hydroperoxide 0.15. Part of the mixed solution was charged and stirred for 30 minutes, and this mixed solution was permeated into the polyorganosiloxane (S1) particles. Next, a mixed liquid of 0.0002 part of ferrous sulfate (relative to 0.7 ppm of latex), 0.0006 part of ethylenediaminetetraacetic acid disodium salt, 0.18 part of Rongalite and 5 parts of distilled water was charged to start radical polymerization. Thereafter, the polymerization was completed by maintaining the internal temperature at 70 ° C. for 90 minutes to obtain a silicone / acrylic composite rubber (X1) latex.
A part of the obtained latex was collected, and the mass average particle diameter of the composite rubber was measured. The latex was dried to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured. As a result, it was 96.7%.
(3) Manufacture of impact strength modifier (BZ1) To the composite rubber (X1) latex obtained above, a mixed solution of 0.08 part of tert-butyl hydroperoxide, 13 parts of methyl methacrylate and 2 parts of ethyl acrylate was added. The mixture was added dropwise at 30 ° C. for 30 minutes, and then held at 65 ° C. for 2 hours to complete the graft polymerization onto the composite rubber to obtain a graft rubber copolymer (GZ1). The polymerization rate of methyl methacrylate was 99.4%. The graft rubber copolymer (GZ1) had a polyorganosiloxane (S1) content of 20% and a composite rubber (X1) content of 85%.
The resulting graft rubber copolymer (GZ1) latex was coagulated with 4.0 parts of calcium acetate (however, the solid content of the latex was 100 parts) and solidified by heat treatment at 90 ° C. Thereafter, the solidified product was washed with warm water and further dried to obtain a powder impact strength modifier (BZ1).

(Production Example 6) Impact strength modifier (BZ2)
(1) Polyorganosiloxane (S1) latex was produced in the same manner as in Production Example 5 (1).
(2) Manufacture of silicone / acrylic composite rubber (X2) latex 30 parts of polyorganosiloxane (S1) latex was sampled in terms of solid content, placed in a separable flask equipped with a stirrer, and 0.2 parts of sodium lauryl sulfate ( (In terms of solid content) and 120 parts of distilled water were added, and after nitrogen substitution, the temperature was raised to 50 ° C., 39.52 parts of n-butyl acrylate, 0.48 parts of allyl methacrylate and 0.15 parts of tert-butyl hydroperoxide Was mixed and stirred for 30 minutes, and this mixed solution was allowed to permeate the polyorganosiloxane (S1) particles.
Next, a mixed liquid of 0.0002 part of ferrous sulfate (relative to 0.7 ppm of latex), 0.0006 part of ethylenediaminetetraacetic acid disodium salt, 0.18 part of Rongalite and 5 parts of distilled water was charged to start radical polymerization. Thereafter, the polymerization was completed by maintaining the internal temperature at 70 ° C. for 90 minutes to obtain a silicone / acrylic composite rubber (X2) latex.
A part of this latex was sampled and the mass average particle diameter of the composite rubber was measured, and it was 200 nm. The latex was dried to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured. As a result, it was 96.7%.
(3) Production of impact strength modifier (BZ2) To the composite rubber (X2) latex obtained above, 0.08 part of tert-butyl hydroperoxide, 22.5 parts of styrene, 7.5 parts of acrylonitrile, ethyl acrylate Two parts of the mixed solution was added dropwise at 65 ° C. over 200 minutes, and then held at 65 ° C. for 2 hours to complete the graft polymerization onto the composite rubber to obtain a graft rubber copolymer (GZ2). The polymerization rate of methyl methacrylate was 99.4%. The graft rubber copolymer (GZ2) had a polyorganosiloxane (S1) content of 30% and a composite rubber (X2) content of 70%.
The obtained graft copolymer (GZ2) latex was coagulated with 4.0 parts of calcium chloride (however, the solid content of the latex was 100 parts) and solidified by heat treatment at 90 ° C. Thereafter, the solidified product was washed with warm water and further dried to obtain a powder impact strength modifier (BZ2).

(Production Example 7) Impact strength modifier (C1)
A comparative impact strength modifier was prepared as follows.
To a separable flask equipped with a stirrer, add 295 parts of distilled water and 1.0 part of potassium tallowate, add 0.4 part of boric acid and 0.04 part of anhydrous sodium carbonate, and stir for 10 minutes. Then, the temperature was raised to 50 ° C., a mixed solution of 83.3 parts of n-butyl acrylate, 1.7 parts of allyl methacrylate and 0.4 part of tert-butyl hydroperoxide was added and stirred for 30 minutes. The organosiloxane particles were infiltrated. Next, a mixture of 0.002 part of ferrous sulfate, 0.006 part of ethylenediaminetetraacetic acid disodium salt, 0.26 part of Rongalite and 5 parts of distilled water was charged to start radical polymerization. The polymerization was completed by maintaining for a time to obtain a polyalkyl (meth) acrylate rubber latex consisting only of the acrylic rubber (P3) component. A part of this latex was sampled and the particle size of the polyalkyl (meth) acrylate rubber was measured in the same manner as in Production Example 3. As a result, it was monodisperse having a peak at 0.22 μm. The latex was dried to obtain a solid, extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured and found to be 97.3%.
To this polyalkyl (meth) acrylate rubber latex, a mixed solution of 0.06 part of tert-butyl hydroperoxide and 15 parts of methyl methacrylate was added dropwise at 70 ° C. over 15 minutes, and then kept at 70 ° C. for 4 hours. The graft polymerization of methyl methacrylate onto polyalkyl (meth) acrylate rubber was completed. The polymerization rate of methyl methacrylate was 97.2%.
The obtained graft rubber copolymer latex was coagulated, separated, washed with 5 parts of aluminum sulfate (provided that the solid content of the latex was 100 parts), dried at 75 ° C. for 16 hours, and powdered impact A strength modifier (C1) was obtained.

(Production Example 8) Production of polyacetal resin (A1) A mixture of trioxane and a small amount of 1,3-dioxolane (comonomer) was polymerized in the presence of boron trifluoride etherate (catalyst) to convert the oxyethylene group to 1 A polyacetal resin (A1) containing 50% was prepared. After the polymerization, the catalyst was deactivated with triethylamine (deactivator), and further pelletized through a terminal stabilization step.

(Examples 1-6, comparative example)
Polyacetal resin and impact strength modifier were blended at the ratio shown in Table 1, and pelletized with a TEM35B type twin screw extruder manufactured by Toshiba Machine to obtain a thermoplastic resin composition. Subsequently, in order to perform various evaluation tests, the obtained thermoplastic resin composition was injection-molded under normal conditions using a SAV60 type injection molding machine manufactured by Sanjo Kikai to prepare a test piece.

(Evaluation test)
The following evaluation tests were performed on the prepared impact strength modifiers and test pieces. Test items and evaluation methods are as follows.
1) Residual aluminum content of impact strength modifier Each prepared impact strength modifier was quantified from the measured value of an atomic absorption photometer according to a dry decomposition method which is a known analytical technique. That is, about 5 g of a sample was weighed, thermally decomposed at about 600 ° C., dissolved in hydrochloric acid, and then made up with 100 cc of pure water and subjected to measurement by an atomic absorption photometer.
2) Izod impact strength The Izod impact strength of the test piece was measured at 23 ° C. according to ASTM D256. The sample thickness was 1/8 inch and a notched specimen was used.
3) Flexural modulus The flexural modulus of the test piece was measured at 23 ° C. according to ASTM D790. The sample thickness was 1/4 inch.

(result)
As shown in Table 1, impact strength modifiers BX1, BX2, mainly composed of a graft rubber copolymer graft-polymerized using at least one emulsifier among sulfonic acid salt compounds and sulfate salt compounds. BY1, BY2, BZ1, and BZ2 all have a small amount of residual aluminum, and in Examples 1 to 6 in which these are blended into a thermoplastic resin composition, there is no decrease in elastic modulus and impact resistance compared to the comparative example. A thermoplastic resin composition having excellent properties was obtained.
In addition, this inventor has confirmed that all the thermoplastic resin compositions obtained in Examples 1-6 are excellent also in characteristics, such as a slidability which polyacetal resin originally has.

  The thermoplastic resin composition of the present invention is suitably used for resin gears and mechanical parts used for OA equipment, information equipment, home appliances, automobiles, clothing, stationery, sundries, building materials, and the like.

Claims (8)

Polyacetal resin (A);
Impact strength modifier (B) comprising, as a main component, a graft rubber copolymer (G) graft-polymerized using at least one emulsifier (E) selected from a sulfonic acid salt compound and a sulfate salt compound And a thermoplastic resin composition. Graft rubber copolymer (G)
A mass average particle diameter _{(d w)} is 80 to 300 nm, and the weight average particle diameter _{(d w)} and the ratio of the number average particle diameter _{(d n) (d w /} d n) is 2 or less butadiene rubber In the presence of the latex containing the polymer (R), a total of 80 to 100 parts by mass of a methacrylic acid ester and an aromatic vinyl compound, and 0 to 20 parts by mass of a vinyl monomer copolymerizable therewith (however, The total amount of these graft monomers is 100 parts by mass.) 0.5 to 10 parts by mass of the emulsifier (E) (however, the total amount of the graft monomers and the butadiene rubber polymer (R) is 100). The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is obtained by graft polymerization. Graft rubber copolymer (G)
an acrylic rubber (P) component containing n-butyl acrylate as a constituent component;
An acrylic rubber (Q) component comprising a (meth) acrylic acid ester of an alcohol having a branched side chain or an alcohol having an alkyl group having 13 or more carbon atoms as a constituent component and having a glass transition temperature lower than that of the acrylic rubber (P) component; The thermoplastic resin composition according to claim 1, comprising: Graft rubber copolymer (G)
A silicone / acrylic composite rubber graft copolymer obtained by graft polymerization of at least one vinyl monomer in the presence of a composite rubber (X) latex containing a polyorganosiloxane and a polyalkyl (meth) acrylate rubber. 2. The thermoplastic resin composition according to claim 1, which is a polymer, has a polyorganosiloxane content of 8 to 70 mass%, and a composite rubber (X) content of 65 to 90 mass%. Stuff.   The thermoplastic resin composition according to any one of claims 1 to 4, wherein the emulsifier (E) is a sulfonic acid salt compound having two phenyl groups. Graft rubber copolymer (G)
6. The polymer latex obtained after graft polymerization is obtained by coagulation using an alkaline earth metal compound as a coagulant (F), according to any one of claims 1 to 5. Thermoplastic resin composition. Graft rubber copolymer (G)
The thermoplastic resin composition according to claim 6, which is obtained using calcium acetate or calcium chloride as the coagulant (F).   The thermoplastic resin composition according to any one of claims 1 to 7, wherein the amount of aluminum ions contained in the impact strength modifier (B) is 35 ppm or less.