JP2011179016A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition with which high impact resistance (especially low-temperature impact resistance) is obtained without seriously impairing pigment colorability and flowability. <P>SOLUTION: The thermoplastic resin composition includes: a composite rubber-based graft copolymer (A) obtained by grafting one or more vinyl monomers to a composite rubber containing polyorganosiloxane and polyalkyl acrylate; and a resin component (B) other than the composite rubber-based graft copolymer (A), wherein a content of the composite rubber-based graft copolymer (A) is 0.5-3.0 pts.mass with respect to 100 pts.mass of the thermoplastic resin composition, a content of polyorganosiloxane in the composite rubber-based graft copolymer (A) is 30-70 mass%, a mass-average particle diameter of the composite rubber-based graft copolymer (A) is 300-2,000 nm, and Dw/Dn (mass-average particle diameter/number-average particle diameter) is 1.0-2.0. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition used as a molding material.

Molded bodies made of thermoplastic resins are widely used in various fields including automotive fields, electrical / electronic equipment fields, office automation equipment such as printers, etc., and these molded bodies have high impact resistance and pigmentation. Characteristics and fluidity are required.
In order to improve the impact resistance of the thermoplastic resin, a method of adding an impact modifier is usually used.
For example, a method has been proposed in which a composite rubber graft copolymer obtained by graft polymerization of a vinyl monomer to a composite rubber composed of polyorganosiloxane and polyalkyl (meth) acrylate is used as an impact modifier. .
Patent Document 1 discloses a silicone / acrylic composite rubber graft copolymer having a number average particle size of 300 to 2000 nm, a polyorganosiloxane content of 20 to 70% by mass, and a composite rubber content of 70 to 90% by mass. A thermoplastic resin composition comprising a coalescence and the composite rubber-based graft copolymer has been proposed. Patent Document 2 discloses a silicone / acrylic composite rubber-based graft copolymer having a polyorganosiloxane content of 65 to 99% by mass, and flame retardancy containing the composite rubber-based graft copolymer and a polycarbonate resin. Thermoplastic resin compositions have been proposed.
However, it is known that the method using a composite rubber-based graft copolymer contains a low-refractive index polyorganosiloxane, so that the pigment colorability is lower than that of other impact modifiers.

  Further, in recent years, a molded body used in the automotive field and OA equipment field has been reduced in thickness, and accordingly, further improvement in the fluidity of the thermoplastic resin is required. However, in the methods described in Patent Document 1 and Patent Document 2, a thermoplastic resin composition that satisfies the required performance has not been obtained.

JP 2004-359889 A JP 2000-17136 A

  The present invention has been made in view of the above circumstances, and provides a thermoplastic resin composition capable of obtaining high impact resistance (particularly impact resistance at low temperatures) without significantly impairing pigment colorability and fluidity. For the purpose.

As a result of intensive studies by the inventor to solve the above-mentioned problems, a composite containing a specific amount of polyorganosiloxane and having a mass average particle diameter and Dw / Dn (mass average particle diameter / number average particle diameter) within a specific range. The inventors have found that a rubber-based graft copolymer may be used, and have invented the following thermoplastic resin composition.
That is, the thermoplastic resin composition of the present invention comprises a composite rubber graft copolymer (A) obtained by grafting one or more vinyl monomers to a composite rubber containing polyorganosiloxane and polyalkyl acrylate. A thermoplastic resin composition containing a resin component (B) other than the composite rubber-based graft copolymer (A), wherein the content of the composite rubber-based graft copolymer (A) is a thermoplastic resin composition. 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the product, the polyorganosiloxane content in the composite rubber-based graft copolymer (A) is 30 to 70% by mass, and the composite rubber-based graft copolymer ( The mass average particle diameter of A) is 300 to 2000 nm, and Dw / Dn (mass average particle diameter / number average particle diameter) is 1.0 to 2.0.
In the thermoplastic resin composition of the present invention, the resin component (B) preferably contains a polycarbonate.
Moreover, in the thermoplastic resin composition of this invention, it is further more preferable that the resin component (B) contains a fluororesin (b2).

  According to the thermoplastic resin composition of the present invention, high impact resistance (especially impact resistance at low temperatures) can be obtained without significantly impairing pigment colorability and fluidity.

[Composite rubber-based graft copolymer (A)]
The composite rubber-based graft copolymer (A) contained in the thermoplastic resin composition of the present invention is obtained by graft-polymerizing one or more vinyl monomers to a composite rubber containing a polyorganosiloxane and a polyalkyl acrylate rubber. And a silicone / acrylic composite rubber graft copolymer.

The composite rubber-based graft copolymer (A) has a mass average particle diameter of 300 to 2000 nm and a mass average particle diameter Dw / number average particle diameter Dn of 1.0 to 2.0. Here, the mass average particle diameter and Dw / Dn are values measured by a capillary particle size distribution meter using the composite rubber-based graft copolymer (A) in a latex state as a measurement sample.
When the mass average particle diameter of the composite rubber-based graft copolymer (A) is less than 300 nm, the impact resistance (particularly, low temperature impact resistance) of the molded product obtained from the thermoplastic resin composition decreases, and the mass average particle When the diameter exceeds 2000 nm, the pigment colorability and impact resistance (particularly low-temperature impact resistance) of the molded product obtained from the thermoplastic resin composition may be deteriorated and the surface appearance of the molded product may be impaired.
When Dw / Dn exceeds 2.0, pigment colorability becomes low. It is theoretically impossible that Dw / Dn is less than 1.0.
In addition, the mass average particle diameter of the composite rubber-based graft copolymer (A) is more preferably 300 to 1000 nm.
The Dw / Dn of the composite rubber-based graft copolymer (A) is more preferably 1.0 to 1.5.

  The polyorganosiloxane content in the composite rubber-based graft copolymer (A) is 30 to 70% by mass. When the polyorganosiloxane content is less than 30% by mass, impact resistance (particularly, low temperature impact resistance) is lowered, and when it exceeds 70% by mass, pigment colorability is lowered.

The composite rubber constituting the composite rubber-based graft copolymer (A) is formed from a polyorganosiloxane and a polyalkyl acrylate rubber. The polyalkyl acrylate rubber preferably has a crosslinked structure and has a glass transition temperature (hereinafter referred to as “Tg”) of 0 ° C. or less.
Among the composite rubbers, a composite rubber obtained by polymerizing an alkyl acrylate component in the presence of polyorganosiloxane is preferable.

The polyorganosiloxane used in the present invention is not particularly limited, but is preferably a polyorganosiloxane containing a vinyl polymerizable functional group.
The polyorganosiloxane having a vinyl polymerizable functional group can be obtained by polymerizing dimethylsiloxane, a siloxane having a vinyl polymerizable functional group, and, if necessary, a siloxane-based crosslinking agent.

Examples of dimethylsiloxane used for the production of polyorganosiloxane include dimethylsiloxane-based cyclic bodies having 3 or more member rings, and those having 3 to 7 members are preferable. Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. These may be used alone or in combination of two or more.
From the viewpoint of easy control of the particle size distribution, it is preferable to use octamethylcyclotetrasiloxane as the main component.

The vinyl polymerizable functional group-containing siloxane is obtained by copolymerizing a monomer containing a vinyl polymerizable functional group and capable of being bonded to dimethylsiloxane via a siloxane bond. In consideration of the reactivity with dimethylsiloxane, it is preferable to use various alkoxysilane compounds containing a vinyl polymerizable functional group. 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 siloxanes.
These vinyl polymerizable functional group-containing siloxanes can be used alone or as a mixture of two or more.

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

  The method for producing the polyorganosiloxane is not particularly limited, but an emulsion obtained by emulsifying a siloxane mixture containing dimethylsiloxane and a vinyl polymerizable functional group-containing siloxane, or a siloxane-based crosslinking agent as necessary with an emulsifier and water. , Using a homomixer that makes fine particles by shearing force by high-speed rotation, a homogenizer that makes fine particles by jet output from a high-pressure generator, etc., and then polymerizing at high temperature using an acid catalyst, and then using an alkaline substance The method of neutralizing an acid is mentioned. In this case, examples of the method for adding the acid catalyst used for the polymerization include a method of mixing with a siloxane mixture, an emulsifier and water, and a method of dropping an emulsion in which the siloxane mixture is microparticulated into a hot acid aqueous solution at a constant rate. . Considering the ease of controlling the particle size of the polyorganosiloxane, a method of polymerizing by maintaining an emulsion containing a siloxane mixture at a high temperature and then mixing an acid catalyst aqueous solution is preferable.

The emulsifier used in producing the polyorganosiloxane is not particularly limited, but an anionic emulsifier and a nonionic emulsifier are preferable.
Examples of the anionic emulsifier include sodium alkylbenzene sulfonate, sodium diphenyl ether disulfonate, sodium alkyl sulfate, polyoxyethylene alkyl sodium sulfate, polyoxyethylene nonyl phenyl ether sodium sulfate, polyoxyethylene alkyl sodium phosphate, polyoxyethylene alkyl phosphoric acid. Calcium is mentioned.
Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene distyrenated phenyl ether, and polyoxyethylene tribenzyl phenyl ether.
These emulsifiers can be used alone or in combination of two or more.

  The method of mixing the siloxane mixture, emulsifier and water includes mixing by high-speed stirring and mixing by a high-pressure emulsifier such as a homogenizer. This is the preferred method.

  Examples of the acid catalyst used for the polymerization of polyorganosiloxane 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 are used alone or in combination of two or more. Of these, the use of mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid is preferred because the particle size distribution of the polyorganosiloxane latex can be narrowed.

The polymerization temperature for obtaining the polyorganosiloxane is preferably 50 ° C. or higher, and more preferably 70 ° C. or higher. The polymerization time for obtaining the polyorganosiloxane is preferably 2 hours or longer, and more preferably 5 hours or longer.
The polymerization can be stopped by cooling the reaction solution and neutralizing the latex to pH 6 to 8 with an alkaline substance such as sodium hydroxide, potassium hydroxide, sodium carbonate, aqueous ammonia solution or the like.

  In the present invention, the mass average particle diameter Dw of the composite rubber-based graft copolymer is 300 to 2000 nm, and the mass average particle diameter Dw / number average particle diameter Dn is 1 while increasing the polyorganosiloxane content in the composite rubber. In order to make it 0.0 to 2.0, it is preferable that the polyorganosiloxane has a mass average particle diameter of 150 to 1000 nm and Dw / Dn of 1.0 to 1.7.

Examples of the alkyl acrylate constituting the composite rubber include alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; hexyl methacrylate, 2-ethylhexyl methacrylate, and n-dodecyl methacrylate. And alkyl methacrylate having 6 or more carbon atoms in the alkyl group. Among the alkyl acrylates, n-butyl acrylate is preferable because the impact resistance and gloss of the molded product obtained from the thermoplastic resin composition are improved.
These alkyl acrylates can be used alone or in combination of two or more.

In order to introduce a crosslinked structure into the polyalkyl acrylate component, it is preferable to polymerize by adding an acrylic crosslinking agent. The polymerized acrylic crosslinking agent also functions as a graft crossing point for the vinyl monomer to be grafted during the production of the graft copolymer (A).
Examples of the acrylic crosslinking agent include allyl methacrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,4-butylene glycol di (meth). Examples include acrylate, triallyl cyanurate, and triallyl isocyanurate. These can be used alone or in combination of two or more.
Although there is no restriction | limiting in particular in content of an acrylic type crosslinking agent, It is preferable that it is 0.1-5.0 mass% in 100 mass% of polyalkyl acrylate components.

Examples of the method for producing the composite rubber include a method of adding an alkyl acrylate component to a polyorganosiloxane latex and polymerizing it using a known radical polymerization initiator to obtain a composite rubber latex.
Examples of a method for adding an alkyl acrylate component to a polyorganosiloxane latex include a method in which an alkyl acrylate component is added to a polyorganosiloxane latex at once, and a method in which an alkyl acrylate component is dropped at a constant rate into a polyorganosiloxane latex. Is mentioned.

In producing the latex of the composite rubber, an emulsifier can be added to stabilize the latex and control the average particle size of the composite rubber.
Examples of the emulsifier used when producing the composite rubber latex include the same emulsifiers as used when producing the above-mentioned polyorganosiloxane latex, and anionic emulsifiers and nonionic emulsifiers are preferred.

  Examples of the polymerization initiator used for the polymerization of the alkyl acrylate component include a peroxide, an azo-based initiator, or a redox-based initiator in which an oxidizing agent / reducing agent is combined. Among these, it is preferable to use a redox initiator, particularly a combination of ferrous sulfate, ethylenediaminetetraacetic acid disodium salt, a reducing agent and a peroxide.

Examples of the peroxide include organic peroxides such as diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide. These can be used alone or in combination of two or more.
Examples of the reducing agent include sodium formaldehyde sulfoxylate, L-ascorbic acid, fructose, dextrose, sorbose, and inositol. These can be used alone or in combination of two or more.

In the presence of the composite rubber as described above, a latex-like composite rubber graft copolymer (A) is obtained by radical polymerization of a graft monomer component composed of one or more vinyl monomers. Can do.
The vinyl monomer is not particularly limited. For example, aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyl toluene; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, and 2-ethylhexyl methacrylate; methyl acrylate And acrylic acid esters such as ethyl acrylate and butyl acrylate; and vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. These vinyl monomers can be used alone or in combination of two or more.
Further, various chain transfer agents and graft crossing agents for adjusting the molecular weight and grafting rate of the graft polymer can be added to the vinyl monomer used in the graft polymerization.

Examples of the graft polymerization method of the graft monomer component onto the composite rubber include a method in which the graft monomer component is added to the latex of the composite rubber and polymerized in one or more stages.
When polymerizing in multiple stages, it is preferable to polymerize by adding the graft monomer component in portions or continuously in the presence of a latex of a composite rubber. By 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.
Examples of the polymerization initiator used for the polymerization of the graft monomer component include the same polymerization initiators used for the polymerization of the alkyl acrylate rubber described above.

When polymerizing the graft monomer component, an emulsifier can be added to stabilize the latex and control the average particle size of the graft copolymer.
Examples of the emulsifier used when the graft monomer component is polymerized include the same emulsifiers as used in the above-described production of the polyorganosiloxane latex, and anionic emulsifiers and nonionic emulsifiers are preferred.
As the usage-amount of the emulsifier at the time of superposing | polymerizing a graft monomer component, 0.1-10 mass parts is preferable with respect to 100 mass parts of graft copolymers, and 0.2-5 mass parts is more preferable.

The composite rubber-based graft copolymer (A) is recovered as a powder from the composite rubber-based graft copolymer latex obtained as described above.
As a method for recovering the powder from the latex, either a spray drying method or a coagulation method can be used.

The spray drying method is a method in which a polymer latex is sprayed in the form of fine droplets in a dryer and dried by applying a heating gas for drying.
Examples of the method for generating fine droplets include a rotating disk type, a pressure nozzle type, a two-fluid nozzle type, and a pressurized two-fluid nozzle type.
The capacity of the dryer may be a small capacity as used in a laboratory or a large capacity as used industrially.
The temperature of the heating gas for drying is preferably 200 ° C. or less, and more preferably 120 to 180 ° C.
The polymer latex to be spray-dried can be used alone or in combination of two or more. Furthermore, in order to improve powder characteristics such as blocking and bulk specific gravity during spray drying, an optional component such as silica can be added to the latex of the polymer and spray dried.

In the coagulation method, a latex polymer is poured into hot water in which calcium chloride, calcium acetate, aluminum sulfate, etc. are dissolved, and the graft copolymer is separated by salting out and solidifying. In this method, the coalesced is recovered by dehydration or the like, and further dried using a pressure dehydrator or a hot air dryer.
Examples of the coagulant used for coagulating the polymer from the latex include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate, and acids such as sulfuric acid. These coagulants may be used alone or in combination of two or more, but when used in combination, it is necessary to select a combination that does not form an insoluble salt in water. For example, it is not preferable to use calcium acetate in combination with sulfuric acid or a salt thereof (sodium salt or the like) or carbonate (sodium salt), since a water-insoluble calcium salt is formed.
The above-mentioned coagulant is usually used as an aqueous solution. The concentration of the coagulant aqueous solution is preferably 0.1% by mass or more, and more preferably 1% by mass or more from the viewpoint that the polymer can be coagulated and recovered stably. Further, the concentration of the coagulant aqueous solution is preferably 20% by mass or less because the amount of the coagulant remaining in the recovered polymer can be reduced and the performance of the molded product such as colorability is hardly deteriorated. More preferably, it is 15 mass% or less.

The method of bringing the latex into contact with the coagulant aqueous solution is not particularly limited. Usually, while stirring the coagulant aqueous solution, the latex is continuously added to the coagulant aqueous solution and kept for a certain period of time. Examples include a method in which a mixture containing a coagulated polymer and water is continuously extracted from the container by continuously injecting it into a container equipped with a stirrer at a constant ratio.
The amount of the coagulant aqueous solution is not particularly limited, but is preferably 10 parts by mass or more, and preferably 500 parts by mass or less with respect to 100 parts by mass of the latex.
The temperature at which the latex is brought into contact with the coagulant aqueous solution is not particularly limited, but is preferably 30 ° C. or higher, and preferably 100 ° C. or lower. The contact time is not particularly limited.

  The solidified polymer is washed with about 1 to 100 times by weight of water, and the filtered polymer in a wet state is dried using a fluid dryer, a press dehydrator or the like. What is necessary is just to determine a drying temperature and drying time suitably with the polymer obtained.

[Resin component (B)]
The resin component (B) used in the present invention is a resin other than the composite rubber-based graft copolymer (A), specifically, a thermoplastic resin that is a resin other than the fluororesin (b2) described later. Examples thereof include resin (b1) and fluorine-based resin (b2).
Specific examples of the thermoplastic resin (b1) include olefin resins such as polypropylene (PP) and polyethylene (PE); polystyrene (PS), high impact polystyrene (HIPS), (meth) acrylate / styrene copolymer (MS ), Styrene / acrylonitrile copolymer (SAN), styrene / maleic anhydride copolymer (SMA), acrylonitrile / butadiene / styrene copolymer (ABS), acrylate / styrene / acrylonitrile copolymer (ASA), Styrene (St) resins such as acrylonitrile / ethylene / propylene rubber / styrene copolymer (AES); acrylic (Ac) resins such as polymethyl methacrylate (PMMA); polycarbonate (PC) resin; polyamide (PA) resin; Polyethylene terephthalate PEs resins such as poly (PET) and polybutylene terephthalate (PBT); (modified) polyphenylene ether ((m-) PPE) resin, polyoxymethylene (POM) resin, polysulfone (PSO) resin, polyarylate (PAr) Resin, engineering plastics such as polyphenylene (PPS) resin; thermoplastic polyurethane (PU) resin; alloy of PC resin such as PC / ABS and St resin, and PVC resin such as PVC / ABS and St resin Alloy, alloy of PA resin such as PA / ABS and St resin, alloy of PA resin and TPE, alloy of PA resin such as PA / PP and polyolefin resin, PC resin such as PC / PBT and PEs resin Alloys with olefin resins such as polyolefin resin / TPE and PP / PE , PPE / HIPS, PPE / PBT, alloys between PPE resins such as PPE / PA, PVC / PMMA and other PVC-based resins and Ac-based resin alloys, etc .; hard vinyl chloride resin, semi-rigid vinyl chloride Examples thereof include PVC resins such as resins and soft vinyl chloride resins.

Among these, St resin, PC resin, PA resin, PET resin, PBT resin, (m-) PPE resin, POM resin, PU resin, alloy of PC resin and St resin such as PC / ABS, PA / Alloy of PA resin such as ABS and St resin, alloy of PA resin and TPE, alloy of PA resin such as PA / PP and polyolefin resin, alloy of PC resin such as PC / PBT and PEs resin, An alloy of PPE resins such as PPE / PBT and PPE / PA is preferable.
Furthermore, it is more preferable that the resin component (B) contains a PC resin because the effects of the present invention are particularly exhibited.

The fluororesin (b2) has a fibril-forming ability and can be easily dispersed in the resin composition and bonded to each other to form fibrils. When fibrils are formed, flame retardancy is improved. Therefore, in order to improve flame retardancy, it is preferable that the resin component (B) contains the fluororesin (b2).
The fluororesin (b2) is preferably at least one compound selected from polytetrafluoroethylene (PTFE) and PTFE modified with an organic polymer (hereinafter abbreviated as “modified PTFE”). . Among these, modified PTFE is more preferable in that the appearance of a molded product obtained by melt molding a thermoplastic resin composition is improved.
As the modified PTFE, those having high affinity with the thermoplastic resin (b1) are preferable from the viewpoint of dispersibility in the resin composition, and a mixture of PTFE and an organic polymer is more preferable.
Examples of the organic polymer monomer for obtaining the modified PTFE include aromatic vinyl monomers such as styrene; (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate; acrylonitrile and the like. Examples thereof include vinyl cyanide monomers. These may be used alone or in combination of two or more.
The organic polymer monomer is one or more selected from aromatic vinyl monomers, (meth) acrylates, and vinyl cyanide monomers in view of affinity with the thermoplastic resin (b1). And a monomer containing at least (meth) acrylate is more preferable.
Specific examples of PTFE include Teflon (registered trademark) 30J (trade name) manufactured by Mitsui DuPont Fluorochemical Co., Ltd. A specific example of the modified PTFE is METABRENE A-3800 (trade name) manufactured by Mitsubishi Rayon Co., Ltd.

  Although the compounding quantity of a fluorine resin (b2) does not have a restriction | limiting in particular, 0.01-5 mass parts with respect to a total of 100 mass parts of a composite rubber-type graft copolymer (A) and a thermoplastic resin (b1). Is preferable, and 0.05 to 2 parts by mass is more preferable. If the blending amount of the fluororesin (b2) is not less than the lower limit, the flame retardancy is further improved, and if it is not more than the upper limit, the fluororesin (b2) can be easily dispersed.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention contains the composite rubber-based graft copolymer (A) described above and a resin component (B).
In the thermoplastic resin composition of the present invention, the content of the composite rubber-based graft copolymer (A) is 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin composition. It is preferable that it is 5-1.5 mass parts. When the content of the composite rubber-based graft copolymer (A) is less than 0.5 parts by mass, the impact resistance improving effect is not sufficiently exhibited. When the content exceeds 3.0 parts by mass, the pigment colorability and fluidity are increased. May decrease.

In the thermoplastic resin composition of the present invention, additives may be appropriately blended within a range that does not impair the original purpose.
Additives include reinforcing agents and fillers such as pigments and dyes, glass fibers, metal fibers, metal flakes, carbon fibers, 2,6-di-butyl-4-methylphenol, 4,4′-butylidene-bis ( Phenolic antioxidants such as 3-methyl-6-t-butylphenol); phosphite antioxidants such as tris (mixed, mono and dinylphenyl) phosphite, diphenyl isodecyl phosphite; dilauryl thiodipropio Nitrate, sulfur-based antioxidants such as dimyristyl thiodipropionate diasterial thiodipropionate; benzotriazoles such as 2-hydroxy-4-octoxybenzophenone and 2- (2-hydroxy-5-methylphenyl) benzotriazole Ultraviolet absorber; bis (2,2,6,6) -tetramethyl-4-pi Light stabilizers such as lysinyl); antistatic agents such as hydroxylalkylamines, sulfonates; lubricants such as ethylenebisstearylamide, metal soaps; and tetrabromophenol A, decabromophenol oxide, TBA epoxy oligomers, TBA polycarbonate oligomers And flame retardants such as antimony trioxide, TPP, and phosphate esters.

  As a method for preparing the thermoplastic resin composition, for example, a composite rubber-based graft copolymer (A) and a resin component (B) are mixed with a Henschel mixer, a tumbler, etc., and then an extruder, a kneader, a mixer, etc. Examples thereof include a melt mixing method and a method in which the composite rubber-based graft copolymer (A) is mixed with the resin component (B) previously melted.

The said thermoplastic resin composition is shape | molded and utilized as a molded article.
Examples of the molding method of the thermoplastic resin composition include an injection molding method, an extrusion molding method, a press molding method, a vacuum molding method, and a blow molding method.

  Since the composite rubber-based graft copolymer (A) contained in the thermoplastic resin composition of the present invention has a large effect of improving impact resistance (particularly, low-temperature impact resistance), the composite rubber-based graft copolymer (A) It is not necessary to increase the blending of. Therefore, the pigment colorability and fluidity are not significantly impaired.

Hereinafter, the present invention will be described more specifically with reference to examples. In the following, “part” and “%” mean “part by mass” and “% by mass”, respectively.
In the following examples, solid content concentration, mass average particle diameter, Dw / Dn, Charpy impact strength, MFR, pigment colorability, and flame retardancy were measured or evaluated.

(1) Solid content concentration of latex Latex was dried with a hot air dryer at 180 ° C. for 30 minutes, and the solid content concentration was calculated by the following formula.
Solid content concentration [%] = [(mass of residue after drying at 180 ° C. for 30 minutes) / (mass of latex before drying)] × 100

(2) Mass average particle diameter, Dw / Dn
Using a latex diluted with deionized water to a concentration of about 3% as a sample, a mass average particle size and Dw / Dn were measured using a CHDF2000 particle size distribution meter manufactured by MATEC, USA.
The measurement was performed under the following standard conditions recommended by MATEC.
Cartridge: Capillary cartridge for particle separation (trade name; C-202)
Carrier liquid: Dedicated carrier liquid (trade name: 2XGR500)
Carrier liquid: almost neutral Carrier liquid flow rate: 1.4 ml / min Carrier liquid pressure: about 4,000 psi (2,600 kPa)
Measurement temperature: 35 ° C
Sample usage: 0.1 ml
Further, as the standard particle size substance, monodisperse polystyrene with a known particle size manufactured by DUKE of the United States having a particle size of 12 points in the range of 40 to 800 nm was used.

(3) Charpy impact strength Charpy impact strength was measured at 23 ° C and -30 ° C according to JIS K7111, using a test piece of a thermoplastic resin composition.

(4) MFR
After the thermoplastic resin composition pellets were pre-dried at 80 ° C. for 12 hours, a melt indexer (manufactured by Techno Seven Co., Ltd.) at a measurement temperature of 300 ° C. under conditions of preheating for 5 minutes and a load of 1.20 kgf. L-243-1531 type) and measured according to JIS K 7210.

(5) Pigment colorability Using a test piece of a thermoplastic resin composition having a thickness of 2 mm, L ^* was measured according to JIS Z 8729 (L ^* a ^* b ^* object color display method by color system). A spectroscopic color difference meter SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd. was used for the measurement. The lower L ^* , the better the pigment colorability.

(6) Flame retardancy Flame retardancy of 1/16 inch combustion rods was measured according to UL-94.
Five specimens with a total combustion time of less than 50 seconds and no drip cotton ignition are "V-0", and those with a total combustion time of 250 seconds or less and no drip cotton ignition are "V-1" Those having a total combustion time of 250 seconds or less and drip cotton ignition were evaluated as “V-2”, and those having a total combustion time exceeding 250 seconds were evaluated as “Fail”.

[Production Example 1] Production of polyorganosiloxane latex (S-1) 2 parts tetraethoxysilane (TEOS), 0.5 part γ-methacryloyloxypropyldimethoxymethylsilane (DSMA) and octamethylcyclotetrasiloxane (momentive Performance Materials Japan GK, product name: TSF-404) 97.5 parts was mixed to obtain 100 parts of a siloxane mixture. To this was added 150 parts of distilled water in which 1.0 part of sodium dodecylbenzenesulfonate (DBSNa) was dissolved, and the mixture was stirred with a homomixer at 10000 rpm for 5 minutes, and then passed twice through the homogenizer at a pressure of 20 MPa for stable premixing. An organosiloxane emulsion was obtained.
The above emulsion was placed in a separable flask equipped with a cooling condenser, and a mixture of 0.20 parts of sulfuric acid and 49.8 parts of distilled water was added over 3 minutes to react. The reaction aqueous solution thus obtained was heated to 80 ° C., maintained for 7 hours, and cooled. Next, this reaction product was kept at room temperature for 6 hours, and then neutralized to pH 7.0 using a 10% aqueous sodium hydroxide solution to obtain a polyorganosiloxane latex (S-1).
The polyorganosiloxane latex (S-1) had a solid content concentration of 29.4%, a mass average particle size of 354 nm, and Dw / Dn of 1.12.

[Production Example 2] Production of polyorganosiloxane latex (S-2) TEOS 2 parts, DSMA 0.5 part and cyclic organosiloxane mixture (manufactured by Shin-Etsu Chemical Co., Ltd., product name: DMC, hereinafter abbreviated as DMC) 5 parts were mixed to obtain 100 parts of an organosiloxane mixture. To this was added 300 parts of distilled water in which 0.68 parts of DBSNa was dissolved, and the mixture was stirred for 2 minutes at 10,000 rpm with a homomixer, and then passed twice through a homogenizer at a pressure of 20 MPa to obtain a stable premixed emulsion.
On the other hand, 10 parts of dodecylbenzenesulfonic acid (DBSH) and 90 parts of ion-exchanged water were injected into a separable flask equipped with a cooling condenser to prepare a DBSH aqueous solution.
While the DBSH aqueous solution was heated to 90 ° C., the premixed emulsion was added dropwise over 4 hours to react, and the temperature was maintained for 2 hours after the completion of the addition and cooled. Next, the obtained reaction product was kept at room temperature for 12 hours, and then neutralized to pH 7.0 using a 10% aqueous sodium hydroxide solution to obtain a polyorganosiloxane latex (S-2).
The polyorganosiloxane latex (S-2) had a solid content concentration of 18.5%, a mass average particle size of 80 nm, and Dw / Dn of 1.11.

[Production Example 3] Production of polyorganosiloxane latex (S-3) 2.0 parts of TEOS, 0.5 part of DSMA and 97.5 parts of DMC were mixed to obtain 100 parts of a siloxane mixture. A solution prepared by dissolving 0.67 part of DBSNa and 0.68 part of DBSH in 150 parts of deionized water was added thereto, and stirred at 10,000 rpm for 5 minutes with a homomixer. Next, the mixture was passed twice through a homogenizer at a pressure of 20 MPa to obtain a stable premixed organosiloxane emulsion.
The above emulsion was put into a separable flask equipped with a cooling condenser, and the temperature was maintained and cooled for 8 hours while being heated to 80 ° C. Subsequently, it neutralized to pH 7.0 using 10% sodium hydroxide aqueous solution, and the latex of polyorganosiloxane (S-3) was obtained.
The polyorganosiloxane latex (S-3) had a solid content concentration of 33.3%, a mass average particle size of 254 nm, and Dw / Dn of 2.54.

[Production Example 4] Production of composite rubber-based graft copolymer (A-1) A polyorganosiloxane latex (prepared in Production Example 1) was placed in a separable flask equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device. S-1) 183.7 parts (54 parts as polyorganosiloxane) was added.
Further, after adding 50 parts of deionized water and mixing, a mixture of 36.0 parts of butyl acrylate (n-BA), 0.6 part of allyl methacrylate (AMA) and 0.15 part of cumene hydroperoxide (CHP) was added. Added.
By passing a nitrogen stream through the separable flask, the atmosphere in the flask was replaced with nitrogen, and the temperature was raised to 60 ° C.
The internal temperature is 60 ° C., 0.001 part of ferrous sulfate (Fe), 0.003 part of disodium ethylenediaminetetraacetate (EDTA), 0.3 part of sodium formaldehyde sulfoxylate (SFS), deionized water 2 An aqueous solution consisting of .5 parts was added, and then held at an internal temperature of 70 ° C. for 1 hour to obtain a composite rubber latex.
A mixture of 9.5 parts of methyl methacrylate (MMA), 0.5 part of methyl acrylate (MA) and 0.03 part of t-butyl hydroperoxide (t-BH) was added to the latex of the composite rubber at an internal temperature of 70 ° C. The polymerization was conducted dropwise for 60 minutes.
After completion of dropping, the mixture was held at an internal temperature of 70 ° C. for 60 minutes and then cooled to obtain a composite rubber-based graft copolymer (A-1) latex. Table 1 shows the measurement results of the weight average particle diameter and Dw / Dn of the obtained composite rubber-based graft copolymer latex (A-1).
Next, 500 parts of an aqueous solution in which calcium chloride was dissolved at a ratio of 7.5% was heated to 60 ° C. and stirred. 340 parts of the latex of the composite rubber graft copolymer (A-1) was gradually dropped into the aqueous calcium chloride solution thus obtained and solidified. The obtained solidified product was separated, washed with water, and dried to obtain a composite rubber-based graft copolymer (A-1).

[Production Examples 5 to 7] Production of composite rubber graft copolymer (A-2 to A-4) Copolymers (A-2 to A-4) were obtained. Further, the mass average particle diameter and Dw / Dn of the obtained composite rubber-based graft copolymer (A-2 to A-4) were measured. The measurement results are shown in Table 1.

[Example 1]
3.0 parts of the composite rubber-based graft copolymer (A-1) obtained in Production Example 4, 97 parts of PC resin (Mitsubishi Engineering Plastics Co., Ltd., Iupilon S-2000F), BASF Japan Co., Ltd. Irganox 245 (referred to as “Irg245” in the table) 0.3 part, PADE-36 manufactured by ADEKA Corporation (referred to as “PEP36” in the table) 0.3 part, Mitsubishi Rayon ( 1.0 part of Metablen A-3800 manufactured by Mitsubishi Chemical Co., Ltd. and carbon black # 960 (indicated in the table as “CB # 960”) 0.4 part by hand are blended and then 30 mm φ twin screw extruder. (L / D = 30) was used to melt and mix at a cylinder temperature of 280 ° C. and a screw rotation speed of 200 rpm to obtain a thermoplastic resin composition. Subsequently, this thermoplastic resin composition was pelletized with a pelletizer.
The obtained pellets were dried at 80 ° C. for 12 hours and then supplied to a 100 t injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., trade name: SE-100DU) at a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. Injection molding was performed to obtain test pieces for various evaluations.
Charpy impact strength, MFR, L ^* , and flame retardancy were evaluated using thermoplastic resin composition pellets and test pieces. The evaluation results are shown in Table 2.

[Example 2, Comparative Examples 1 to 4]
A pellet and a test piece of a thermoplastic resin composition were obtained in the same manner as in Example 1 except that the type and addition amount of the composite rubber-based graft copolymer were changed to those shown in Table 2. Charpy impact strength, MFR, L ^* , and flame retardancy were evaluated using thermoplastic resin composition pellets and test pieces. The evaluation results are shown in Table 2.

As is clear from Example 1, the thermoplastic resin composition using the composite rubber-based graft copolymer specified in the present invention has high Charpy impact strength at −30 ° C. and excellent impact resistance at low temperatures. It was. Moreover, L ^* value which shows pigment coloring property is 10 or less, it was excellent also in pigment coloring property, and it had fluidity | liquidity and a flame retardance.
In the thermoplastic resin composition of Example 2, the amount of the composite rubber-based graft copolymer added is smaller than that of Example 1. The thermoplastic resin composition of Example 2 had high Charpy impact strength at −30 ° C. and excellent impact resistance at low temperatures even when the composite rubber-based graft copolymer was reduced. Further, since the amount of the composite rubber-based graft copolymer added was low, the L ^* value was small, the pigment colorability was excellent, and the flame retardancy was also excellent.
On the other hand, the thermoplastic resin composition of Comparative Example 1 had low Charpy impact strength and flame retardancy at −30 ° C. because the polyorganosiloxane content in the composite rubber-based graft copolymer used was small.
The thermoplastic resin composition of Comparative Example 2 had a low Charpy impact strength at −30 ° C. because the composite rubber-based graft copolymer used had a small mass average particle size.
In the thermoplastic resin composition of Comparative Example 3, since the Dw / Dn of the composite rubber-based graft copolymer used exceeded 2.0, L ^* was large and the pigment colorability was low.

Since the thermoplastic resin composition of the present invention has an excellent balance of impact resistance (particularly low temperature impact resistance), pigment colorability, and fluidity, miscellaneous goods such as building materials, automobiles, toys, and stationery, as well as OA equipment and home appliances. It is widely useful in various fields including equipment.

Claims (3)

Composite rubber-based graft copolymer (A) obtained by grafting one or more vinyl monomers on a composite rubber containing polyorganosiloxane and polyalkyl acrylate, and a resin other than the composite rubber-based graft copolymer (A) A thermoplastic resin composition comprising a component (B),
The content of the composite rubber-based graft copolymer (A) is 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin composition,
The polyorganosiloxane content in the composite rubber-based graft copolymer (A) is 30 to 70% by mass, the mass average particle diameter of the composite rubber-based graft copolymer (A) is 300 to 2000 nm, Dw / Dn (mass average particle) A thermoplastic resin composition having a diameter / number average particle diameter of 1.0 to 2.0.   The thermoplastic resin composition according to claim 1, wherein the resin component (B) contains a polycarbonate resin.   The thermoplastic resin composition according to claim 1 or 2, wherein the resin component (B) contains a fluororesin (b2).