JP2015061893A - Slidability improver for polyolefin resin, polyolefin resin composition, and molded product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slidability improver for a polyolefin resin, which exhibits a slidability-improving effect by being added to a polyolefin resin.SOLUTION: A slidability improver (A) for a polyolefin resin comprises a rubber-containing graft copolymer (a) obtained by grafting one or more vinyl monomers onto a polyorganosiloxane-containing rubber. The rubber-containing graft copolymer (a) has a toluene-insoluble content of 10 mass% or more. The polyorganosiloxane-containing rubber is a composite rubber comprising a polyorganosiloxane and a polyalkyl (meth)acrylate.

Description

  The present invention relates to a polyolefin resin slidability improver capable of imparting a high degree of slidability by being blended with a polyolefin resin, a polyolefin resin composition containing the slidability improver, and a molded article thereof.

  Polyolefin resin is a general-purpose plastic used in various fields because it is lightweight, has high rigidity, and is inexpensive. Utilizing the characteristics of light weight and high rigidity, it is widely used especially for automobile members.

In recent years, the automobile industry has been increasingly hybridized and electric vehicles, and the demand for reducing the squeaking noise of plastic members accompanying the quietness of indoor spaces is rapidly increasing. For this reason, the need regarding the slidability improvement of a plastic member, especially polyolefin resin is increasing. When slidability is imparted to the resin material, the scratch resistance is also improved, and the need for a slidability improver for polyolefin resins, which inherently has a problem with scratch resistance, is increasing.

Technological development for imparting slidability to a thermoplastic resin has been performed for a long time, and it is known that high slidability can be imparted by blending silicone oil into a thermoplastic resin. For example, Patent Document 1 describes that high slidability can be imparted by blending silicone oil with ethylene propylene rubber. However, the technology for imparting slidability by blending silicone oil is a technology for imparting slidability by bleeding low-molecular-weight silicone oil on the surface of the molded product, resulting in excessive bleed over time, resulting in stickiness on the surface of the molded product. In addition to problems such as feeling, there was a problem that sliding performance deteriorated when the surface was wiped with a solvent or the like.

As a slidability improving technique that does not cause the above problems, a technique of blending a fluororesin with a thermoplastic resin is known. For example, Patent Document 2 describes that high slidability can be imparted to a molded body obtained by blending a fluororesin with a polyamide resin. However, in recent years, there has been a strong demand for dehalogenation in automobile parts due to increasing interest in environmental problems, and the blending of fluororesins is greatly limited.

A technique for blending a polyorganosiloxane-based graft copolymer into a thermoplastic resin is known as a slidability imparting technique that does not have a stickiness with time and does not contain a halogen element. For example, in Patent Document 3, a graft polymer obtained by grafting one or more vinyl monomers to a composite rubber composed of polyorganosiloxane and polyalkyl (meth) acrylate is blended in a polycarbonate resin. Although a technique capable of obtaining a resin composition having no stickiness and excellent slidability is described, there is no description of an example in which the graft copolymer is applied to a polyolefin resin. Further, as a technique for blending a polyorganosiloxane-containing graft polymer into a polyolefin resin, although described in Patent Document 4, it is blended as a flame retardant aid and there is no description regarding slidability.

JP-A-4-275353 JP 2005-239902 A JP 2011-26476 A JP 2000-26664 A

  The present invention provides a slidability improver for polyolefin resins that can impart high slidability by being blended with a polyolefin resin, a polyolefin resin composition containing the slidability improver and a polyolefin resin, and a molded article thereof. There is to do.

  The present invention relates to a polyolefin resin slidability improver (A) comprising a rubber-containing graft copolymer (a) obtained by grafting one or more vinyl monomers to a rubber containing polyorganosiloxane. The present invention also relates to a polyolefin resin composition comprising the polyolefin resin slidability improver (A) and a polyolefin resin. Furthermore, this invention relates to the molded object obtained by shape | molding the said thermoplastic resin composition.

  By blending the slidability improver of the present invention with a polyolefin resin, a high degree of slidability can be imparted.

In the present invention, “(meth) acrylate” means at least one of “methacrylate” or “acrylate”.
The slidability improver for polyolefin (A) of the present invention comprises a rubber-containing graft copolymer (a) obtained by grafting one or more kinds of vinyl monomers to a rubber containing polyorganosiloxane.

In the present invention, the rubber containing a polyorganosiloxane is preferably a polyorganosiloxane rubber or a composite rubber containing a polyorganosiloxane rubber and a polyalkyl (meth) acrylate, and particularly preferably a polyorganosiloxane rubber. preferable. As the polyorganosiloxane rubber, polydimethylsiloxane rubber is particularly preferable. Use of the polyorganosiloxane rubber is advantageous because a higher slidability improvement effect can be obtained with a small amount of addition.

  A polyorganosiloxane is a polymer containing an organosiloxane unit as a constituent unit. The polyorganosiloxane rubber can be obtained by polymerizing organosiloxane or an organosiloxane mixture containing components used as necessary. Examples of components used as necessary include a siloxane-based crosslinking agent, a siloxane-based graft crossing agent, and a siloxane oligomer having a terminal blocking group.

  As the organosiloxane, either a chain organosiloxane or a cyclic organosiloxane can be used. Cyclic organosiloxanes are preferred because they have high polymerization stability and a high polymerization rate. The cyclic organosiloxane is preferably a 3- to 7-membered ring, and examples thereof include the following compounds. Hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane and the like. These organosiloxanes can be used alone or in admixture of two or more. Among these organosiloxanes, 60% by mass or more is preferably octamethylcyclotetrasiloxane because the particle diameter of the polyorganosiloxane rubber can be easily controlled.

  As the siloxane-based crosslinking agent, those having a siloxy group are preferable. By using a siloxane-based crosslinking agent, a polyorganosiloxane having a crosslinked structure can be obtained. By causing the polyorganosiloxane to have a cross-linked structure, the transition of the polyorganosiloxane to the surface of the molded body over time can be suppressed, and stickiness on the surface of the molded body can be suppressed. Examples of the siloxane crosslinking agent include trifunctional or tetrafunctional crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. Can do. Among these, a tetrafunctional crosslinking agent is preferable, and tetraethoxysilane is particularly preferable. Although content of a siloxane type crosslinking agent is not specifically limited, It is preferable that it is 0.1-30 mass% in 100 mass% of organosiloxane mixtures.

  The siloxane-based graft crossing agent has a siloxy group and a functional group copolymerizable with a vinyl monomer. By using a siloxane-based graft crossing agent, a polyorganosiloxane having a functional group copolymerizable with a vinyl monomer can be obtained. By using such a graft crossing agent, an alkyl (meth) acrylate component for composite rubber, which will be described later, or a vinyl monomer for grafting described later can be grafted to the polyorganosiloxane by radical polymerization.

  Examples of the siloxane-based graft crossing agent include β- (meth) acryloyloxyethyldimethoxymethylsilane, γ- (meth) acryloyloxypropyldimethoxymethylsilane, γ- (meth) acryloyloxypropylmethoxydimethylsilane, γ- (meta (Meth) such as acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylethoxydiethylsilane, γ- (meth) acryloyloxypropyldiethoxymethylsilane, δ- (meth) acryloyloxybutyldiethoxymethylsilane Acryloyloxysilane; vinylsiloxanes such as tetramethyltetravinylcyclotetrasiloxane and methoxydimethylvinylsilane; vinylphenylsilanes such as p-vinylphenyldimethoxymethylsilane; γ -Mercaptosiloxanes such as mercaptopropyldimethoxymethylsilane and γ-mercaptopropyltrimethoxysilane; 1,3-bis (3-methacryloyloxypropyl) tetramethyldisiloxane, 1,3-bis (3-mercaptopropyl) tetramethyldi Examples include disiloxanes such as siloxane.

  These may be used alone or in combination of two or more. As content of a siloxane type graft crossing agent, it is preferable that it is 0.5-20 mass% in 100 mass% of organosiloxane mixtures.

  The siloxane oligomer having a terminal blocking group has an alkyl group or the like at the terminal of the organosiloxane oligomer and has a role of stopping the polymerization of the polyorganosiloxane. Examples of the siloxane oligomer having a terminal blocking group include hexamethyldisiloxane, 1,3-bis (3-glycidoxypropyl) tetramethyldisiloxane, and 1,3-bis (3-aminopropyl) tetramethyldisiloxane. And methoxytrimethylsilane.

  Further, 1,3-bis (3-methacryloyloxypropyl) tetramethyldisiloxane exemplified as a siloxane having a vinyl polymerizable functional group can also be used as a siloxane having a terminal blocking group.

The method for producing the polyorganosiloxane rubber is not particularly limited, and can be produced by a known method as described below.
First, emulsifying by adding an emulsifier, an acid catalyst and water to a siloxane mixture containing an organosiloxane, if necessary, a siloxane grafting agent, a siloxane crosslinking agent, and a siloxane oligomer having a terminal blocking group as required. To obtain a siloxane latex.

  Next, the siloxane latex is finely divided using a homomixer that makes fine particles by a shearing force generated by high-speed rotation, a homogenizer that makes fine particles by a jet output from a high-pressure generator, and the like to obtain a finely divided siloxane latex. As a method for obtaining finely divided siloxane latex, a method using a homogenizer is preferable because the particle size distribution of the silicone polymer can be reduced.

  Thereafter, the micronized siloxane latex is polymerized at a high temperature of 80 ° C., for example. After the polymerization, it is neutralized with an alkaline substance to obtain a latex of a silicone polymer.

  The emulsifier used in producing the latex of the silicone polymer 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, sodium polyoxyethylene alkyl sulfate, and sodium polyoxyethylene nonyl phenyl ether sulfate.

  Examples of the nonionic emulsifier include polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tribenzylphenyl ether, and polyoxyethylene polyoxypropylene glycol. These emulsifiers can be used alone or in combination of two or more.

  Although it does not specifically limit as the usage-amount of an emulsifier, 0.05-30 mass% is preferable in 100 mass% of siloxane mixtures. If the amount of the emulsifier used is 0.05% by mass or more in 100% by mass of the siloxane mixture, the emulsified dispersion state of the siloxane mixture becomes stable, and if it is 30% by mass or less, coloring of the resulting resin composition is suppressed. be able to.

  Examples of the acid catalyst used when polymerizing the siloxane mixture 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 can be used alone or in combination of two or more.

  As usage-amount of an acid catalyst, 0.05-10 mass% is preferable in 100 mass% of siloxane mixtures, and 0.2-5 mass% is more preferable. If the amount of the acid catalyst used is 0.05% by mass or more, the polymerization rate of the siloxane mixture is appropriate and the productivity of the silicone polymer is good. If the amount is 10% by mass or less, the resulting resin composition is colored. Can be suppressed.

Examples of the method for adding the acid catalyst in producing the silicone polymer include a method of adding the catalyst at a time to the latex of the siloxane mixture, and a method of dropping at a constant rate into the latex of the siloxane mixture.

  The polymerization of the siloxane mixture can be stopped, for example, by cooling the reaction solution and neutralizing the latex by adding an alkaline substance such as sodium hydroxide, potassium hydroxide, sodium carbonate, or ammonia.

  In the present invention, as the rubber containing polyorganosiloxane, a composite rubber containing polyorganosiloxane and polyalkyl (meth) acrylate (hereinafter sometimes abbreviated as “the present composite rubber”) can be used.

The polyalkyl (meth) acrylate used in the present composite rubber has a crosslinked structure, and preferably has a glass transition temperature represented by the following FOX formula of 0 ° C. or lower.
1 / (273 + Tg) = Σ (wi / (273 + Tgi)).
In the above formula, Tg is the glass transition temperature (° C.) of the copolymer, wi is the mass fraction of monomer i, and Tgi is the glass transition temperature of the homopolymer obtained by polymerizing monomer i. (° C). The value of Tg of the homopolymer is a value described in POLYMER HANDBOOK Volume 1 (WILEY-INTERSCIENCE).

  In addition to polyorganosiloxane and polyalkyl (meth) acrylate, the present composite rubber may contain a butadiene-based rubber or a polymer having a glass transition temperature exceeding 0 ° C. as necessary.

  The polyalkyl (meth) acrylate can be obtained by polymerizing an alkyl (meth) acrylate component. As the alkyl (meth) acrylate component, it is preferable to use an alkyl (meth) acrylate and, if necessary, an acrylic crosslinking agent and an acrylic graft crossing agent. By providing a chemical bond with the vinyl monomer used for graft polymerization using an acrylic graft crossing agent, the dispersibility in the polyolefin resin can be improved, and the appearance of the molded article is not deteriorated.

  Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, 2-ethylhexyl ( Examples include alkyl (meth) acrylates such as (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and n-dodecyl (meth) acrylate. Among the alkyl (meth) acrylates, n-butyl acrylate is preferable because of excellent polymerization stability. These alkyl (meth) acrylates can be used alone or in combination of two or more.

Examples of the acrylic crosslinking agent include the following. Divinylbenzene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, triallyl trimellitate, etc. These may be used alone or in combination of two or more.
Examples of the acrylic graft crossing agent include the following. Allyl (meth) acrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate and the like. These acrylic graft crossing agents may be used alone or in combination of two or more.

  Examples of the method for producing the composite rubber include a method of adding an alkyl (meth) acrylate component to a polyorganosiloxane latex and performing polymerization using a known radical polymerization initiator to obtain a composite rubber latex. Can be mentioned.

  Examples of the method of adding the alkyl (meth) acrylate component to the polyorganosiloxane latex include a method of adding the alkyl (meth) acrylate component to the polyorganosiloxane latex at once, and the alkyl (meth) to the polyorganosiloxane latex. The method of dripping an acrylate component at a fixed speed is mentioned. Among the above methods, a method in which an alkyl (meth) acrylate component is added to the polyorganosiloxane latex in a batch is preferable because the impact resistance of the resulting molded article is improved.

  In producing the latex of the composite rubber, an emulsifier can be added in order to stabilize the latex and control the volume 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 (meth) acrylate component include one or more polymerization initiators selected from peroxides, organic peroxides, and azo initiators. As for the peroxide, there are a case where the peroxide is used alone and a case where it is used as a redox initiator in combination with a reducing agent. Similarly, the organic peroxide may be used alone or in combination with a reducing agent or the like as a redox initiator. The azo initiator includes an oil-soluble azo initiator and a water-soluble azo initiator.

  Examples of the peroxide include hydrogen peroxide, potassium persulfate, and ammonium persulfate. These can be used alone or in combination of two or more.

  Examples of the organic peroxide include diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, succinic acid peroxide, and t-butyl peroxyneodecanoate. , T-butylperoxyneoheptanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexa Noate. These organic peroxides can be used alone or in combination of two or more.

  When a peroxide or organic peroxide is combined with a reducing agent to form a redox initiator, the above peroxide or organic peroxide, sodium formaldehyde sulfoxylate, L-ascorbic acid, fructose, dextrose, It is preferable to use a reducing agent such as sorbose or inositol in combination with ferrous sulfate / ethylenediaminetetraacetic acid disodium salt. These reducing agents can be used alone or in combination of two or more.

  Examples of the oil-soluble azo initiator include 2,2'-azobisisobutyronitrile and dimethyl 2,2'-azobis (2-methylpropionate). These can be used alone or in combination of two or more.

  Examples of the water-soluble azo initiator include 4,4′-azobis (4-cyanovaleric acid) and 2,2′-azobis [N- (2-carboxymethyl) -2-methylpropionamidine] hydride. Water, 2,2′-azobis- (N, N′-dimethyleneisobutylamidine) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, etc. Azo initiators. These can be used alone or in combination of two or more.

  The polyorganosiloxane content in the composite rubber (100% by mass) is not particularly limited, but is preferably 1% by mass or more. When the content of the polyorganosiloxane in the composite rubber is 1% by mass or more, the slidability of the resulting molded product can be imparted. The polyorganosiloxane content is preferably 30 to 99% by mass, more preferably 50 to 95% by mass, and particularly preferably 70 to 90% by mass.

  The volume average particle diameter of the latex of the rubber (polyorganosiloxane rubber or composite rubber) containing the polyorganosiloxane of the present invention is not particularly limited, but is preferably in the range of 50 to 1000 nm. If the volume average particle diameter is 50 nm or more, the latex stability is excellent, and if it is 1000 nm or less, excellent slidability can be imparted to the resulting molded article.

  The polyorganosiloxane-containing graft copolymer (a) of the present invention can be obtained by graft polymerization of one or more vinyl monomers to a rubber containing polyorganosiloxane. The graft component coats the polyorganosiloxane rubber and imparts powder handleability when the powder is recovered, and also serves to disperse the polyorganosiloxane when mixed with the polyolefin resin.

  The vinyl monomer used for the graft polymerization is not particularly limited, and any monomer can be used. Examples of the vinyl monomer for graft polymerization include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i- Alkyl (meth) acrylates such as butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene; acrylonitrile And vinyl cyanides such as methacrylonitrile. The above vinyl monomers can be used alone or in combination of two or more.

Graft monomer component (Examples of the polymerization method of the vinyl monomer for graft polymerization include a method in which the graft monomer component is added to a latex of rubber containing polyorganosiloxane and polymerized in one or more stages. When the graft monomer component is polymerized to the polyorganosiloxane rubber, it is preferable to use an acrylic graft crossing agent to have a chemical bond with the graft monomer component.The graft polymer and the rubber layer have a chemical bond. Therefore, the dispersibility in the polyolefin resin can be improved, and the appearance of the molded product is not deteriorated.

  When the polymerization is performed in multiple stages, it is preferable to polymerize by adding the graft monomer component in a divided or continuous manner in the presence of a rubber latex containing polyorganosiloxane. 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 (meth) acrylate component 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 polymer. 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.

The polyorganosiloxane content in 100% by mass of the polyorganosiloxane-containing graft polymer (a) of the present invention is not particularly limited, but is preferably in the range of 10% by mass to 95% by mass. When the content of the polyorganosiloxane is 10% by mass or more, high slidability can be imparted to the obtained molded body. The polyorganosiloxane content is preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 70% by mass or more. If the polyorganosiloxane content is 95% or less, sufficient powder handling properties can be imparted to the resulting polyorganosiloxane-containing graft polymer (a).

  The volume average particle diameter of the polyorganosiloxane-containing graft polymer (a) of the present invention is preferably 50 to 1000 nm because latex stability and slidability and surface appearance of the resulting molded article are improved. If the volume average particle diameter is 50 nm or more, the polymerization stability of the obtained latex can be ensured. Moreover, if a volume average particle diameter is 1000 nm or less, the high slidability and surface appearance will become favorable to the molded object obtained.

The content of the graft component in 100% by mass of the polyorganosiloxane-containing graft polymer (a) of the present invention is not particularly limited, but is preferably in the range of 1 to 99% by mass. When the content of the graft component is 1% by mass or more, high powder handleability can be imparted to the obtained graft copolymer. Moreover, if content of a graft component is less than 99 mass%, high slidability can be provided to the obtained molded object. The content of the graft component is preferably 3 to 80% by mass, and more preferably 5 to 50% by mass.
The amount of toluene insoluble matter in the polyorganosiloxane-containing graft polymer (a) of the present invention is not particularly limited, but is preferably 10% by mass or more. If the amount of toluene insolubles is 10% by mass or more, it is possible to suppress the sticky feeling of the surface of the molded body and the change in sliding performance of the molded body over time due to the bleed-out of low molecular weight siloxane over time. The amount of toluene insoluble is preferably 30% by mass or more, more preferably 50% by mass or more, particularly preferably 70% by mass or more, and most preferably 85% by mass or more. In order to control the toluene insoluble content to 10% by mass or more, a siloxane-based crosslinking agent, a siloxane-based grafting agent, or the like is used to cause the polyorganosiloxane to have a crosslinked structure or when a vinyl monomer is grafted. This can be achieved by using an acrylic graft crossing agent.

  The polyorganosiloxane-containing graft copolymer (a) of the present invention is obtained by emulsion polymerization of the polyorganosiloxane-containing graft polymer (a).

  The recovery method of the obtained polyorganosiloxane-containing graft copolymer (a) is not particularly limited, and can be recovered by a known method such as coagulation recovery, spray drying (spray drying) recovery, freeze drying recovery, and centrifugal recovery. Among these recovery methods, the coagulation method and the spray drying method are preferable from the viewpoint of uniformity of the obtained polyorganosiloxane-containing graft copolymer (a) powder.

  When powder recovery of the polyorganosiloxane-containing graft copolymer (a) is performed using a coagulation recovery method, the latex of the polyorganosiloxane-containing graft copolymer (a) is brought into contact with a coagulant at 30 to 90 ° C. The powder of the polyorganosiloxane-containing graft copolymer (a) can be recovered by coagulating with stirring to form a slurry and dehydrating and drying. Examples of the coagulant used in the coagulation recovery method include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; organic acids such as formic acid and acetic acid; inorganic salts such as aluminum sulfate, magnesium sulfate and calcium sulfate; and organic acids such as calcium acetate. Examples include salts.

  When powder recovery of the polyorganosiloxane-containing graft copolymer (a) is performed using a spray drying method, the latex of the polyorganosiloxane-containing graft copolymer (a) is treated with an inlet temperature of 120 to 220 ° C. and an outlet temperature of 40. The powder of the polyorganosiloxane-containing graft copolymer (a) can be recovered by spray drying with a spray dryer under the condition of ˜90 ° C. The outlet temperature is preferably 40 to 80 ° C., and preferably 40 to 70 ° C., from the viewpoint of the ability of the polyorganosiloxane-containing graft copolymer (a) to be pulverized into primary particles. Further preferred.

  As the polyorganosiloxane-containing graft copolymer (a) of the present invention, the same polymer may be used alone, or two or more polymers having different compositions, particle sizes, etc. may be used in combination.

  The polyorganosiloxane-containing graft copolymer (a) of the present invention exhibits high slidability imparting ability when blended with a polyolefin resin.

  The polyolefin resin in the present invention refers to a homopolymer of an olefin monomer or a copolymer containing 50% by mass or more of an olefin monomer, and examples of the olefin monomer include ethylene, propylene, Examples include 1-butene, 1-hexene, 1-decene, 1-octene, and 4-methyl-1-pentene. Specific examples of homopolymers of olefin monomers or copolymers mainly composed of olefin monomers include, for example, low density polyethylene, high density polyethylene, polypropylene, ethylene / propylene copolymer, polymethyl Examples include pentene, polybutene, and mixed resins thereof. Among these polyolefin resins, polypropylene and polyethylene are preferable, and polypropylene is particularly preferable from the viewpoint of the effect of improving the slidability by blending the slidability improver (A) of the present invention.

The polyolefin resin composition of the present invention contains a slidability improver (A) and a polyolefin resin (B). The ratio of the slidability improver (A) in the polyolefin resin composition of the present invention can be freely set according to the sliding performance of a molded product obtained by molding the polyolefin resin composition. The ratio of the slidability improver (A) is preferably 0.1 to 40% by mass when the total amount of the polyolefin resin composition is 100% by mass. When the concentration of the slidability improver (A) in the polyolefin resin composition is 0.1% by mass or more, a sufficient slidability improving effect is exhibited. If the density | concentration of a slidability improvement agent (A) is 40 mass% or less, the change of physical properties, such as an elasticity modulus, will be slight in the molded object obtained. As a density | concentration of a slidability improvement agent (A), 0.2-25 mass% is more preferable, It is more preferable that it is 0.5-15 mass%, It is especially preferable that it is 0.5-7 mass%. .

The thermoplastic resin composition of the present invention may contain other additives in addition to the slidability improver (A) and the polyolefin resin (B). Examples of other additives include fillers, flame retardants, antioxidants, light stabilizers, lubricants, and foaming agents.

Examples of the filler (C) include talc, calcium carbonate, mica, glass fiber, carbon fiber, magnesium carbonate, kaolin, calcium sulfate, barium sulfate, titanium white, white carbon, and carbon black. These fillers can be used alone or in combination of two or more. Among these fillers, talc, calcium carbonate, and mica are preferably used as automobile members. The amount of the filler is not particularly limited, and is preferably in the range of 1 to 100 parts by mass when the total of the slidability improver (A) and the polyolefin resin (B) is 100 parts by mass.

Examples of the flame retardant include “FR-1025M”, “FR-1524”, “FR-2124”, “F-2016”, “F-2300”, “F-2310”, “F-2300H” (product) Name, manufactured by ICL-IP Japan Co., Ltd.); “Frame Cut 120G”, “Frame Cut 121K”, “Frame Cut 122K” (trade name, manufactured by Tosoh Corporation); “SAYTEX RB-100”, “SAYTEX BT” Bromine-based flame retardants such as “-93”, “SAYTEX BT-93W”, “SAYTEX 8010”, “SAYTEX HP-7010P” (trade name, Albemarle Japan Co., Ltd.); 2200 "," ADK STAB FP-2200S "(trade name, ADEKA Corporation); Phosphate flame retardants such as “P770” (trade name, Suzuhiro Chemical Co., Ltd.); “TPP”, “TCP”, “TXP”, “CDP”, “CR-733S”, “CR-741”, “PX-200”, “TMCPP”, “CR-900”, “CR-509”, “CR-530”, “CR-504L” (trade name, Daihachi Chemical Industry Co., Ltd.); “ADK STAB PFR” , "Adekastab FP-500", "Adekastab FP-600" (trade name, ADEKA Co., Ltd.) and other phosphate ester flame retardants; flame retardants mainly composed of magnesium hydroxide, mainly composed of aluminum hydroxide Flame retardants, and mixtures thereof. These flame retardants may be used alone or in combination of two or more. The amount of the flame retardant is not particularly limited, and is preferably in the range of 1 to 200 parts by mass when the total of the slidability improver (A) and the polyolefin resin (B) is 100 parts by mass.

As the antioxidant, known antioxidants such as hindered phenol antioxidants, sulfur antioxidants, phosphorus antioxidants and the like can be used. These antioxidants may be used alone or in combination of two or more. The amount of the antioxidant is not particularly specified, and is preferably in the range of 0.1 to 2 parts by mass when the total of the slidability improver (A) and the polyolefin resin (B) is 100 parts by mass. When the amount of the antioxidant is within this range, the antioxidant ability can be imparted.

As the light stabilizer, known light stabilizers such as an ultraviolet absorber and a hindered amine light stabilizer can be used. These light stabilizers may be used alone or in combination of two or more. The amount of the light stabilizer is not particularly defined, and is preferably in the range of 0.1 to 2 parts by mass when the total of the slidability improver (A) and the polyolefin resin (B) is 100 parts by mass. When the amount of the light stabilizer is within this range, a light stabilizing function can be imparted.

  Examples of the lubricant include sodium, calcium or magnesium salts of lauric acid, palmitic acid, oleic acid or stearic acid. These lubricants may be used individually by 1 type, and may use 2 or more types together. The amount of the lubricant is not particularly limited, and is preferably in the range of 0.1 to 3 parts by mass when the total of the slidability improver (A) and the polyolefin resin (B) is 100 parts by mass. If the amount of the lubricant is within this range, it is possible to impart lubricity during extrusion.

As the foaming agent, known foaming agents such as inorganic foaming agents, volatile foaming agents, and decomposable foaming agents can be used.
Examples of the inorganic foaming agent include carbon dioxide, air, and nitrogen.
Examples of volatile blowing agents include aliphatic hydrocarbons such as propane, n-butane, i-butane, pentane and hexane; cyclic aliphatic hydrocarbons such as cyclobutane and cyclopentane; trichlorofluoromethane and dichlorodifluoromethane. Halogenated hydrocarbons such as dichlorotetrafluoroethane, methyl chloride, ethyl chloride, and methylene chloride.
Examples of the decomposable foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutyronitrile, and sodium bicarbonate.
These foaming agents may be used individually by 1 type, and may use 2 or more types together. The amount of the foaming agent is not particularly defined and can be arbitrarily set according to the desired foaming ratio. As a quantity of a foaming agent, when the sum total of a slidability improvement agent (A) and polyolefin resin (B) is 100 mass parts, it is preferable that it is the range of 0.1-10 mass parts. When the amount of the foaming agent is within this range, a foamed molded product can be obtained without deteriorating the appearance of the resulting molded product.

As a method of mixing the slidability improver (A), the polyolefin resin, and other additives as necessary, known melt kneading such as extrusion kneading and roll kneading can be used.

  The melt-kneading method is not particularly limited, and the slidability improver (A) of the present invention and the polyolefin resin (B) may be simultaneously melt-kneaded, and the total amount of the slidability improver (A) After melt-kneading a part of polyolefin resin (B) and manufacturing a masterbatch, you may melt-knead the said masterbatch and the remainder of polyolefin resin (B). When melt-kneading after creating the master batch, the polyolefin resin (B) at the time of creating the master batch and the polyolefin resin (B) to which the master batch is added may be the same or different types of polyolefin resins may be used. good.

  The content of the slidability improver (A) in the masterbatch is not particularly defined and can be blended at an arbitrary ratio. The content of the slidability improver (A) in 100% by mass of the master batch is preferably 1 to 70% by mass. If the density | concentration of a slidability improvement agent (A) is 1 mass% or more, sufficient slidability can be provided to the molded object obtained. If the density | concentration of a slidability improvement agent (A) is 70 mass% or less, a masterbatch can be extruded stably. In addition, it is also free to add other modifiers such as a filler and a flame retardant into the master batch containing the slidability improver (A).

  The melt-kneading temperature can be appropriately set according to the type of the polyolefin resin, and is preferably 160 to 280 ° C, more preferably 180 to 240 ° C.

The molded article of the present invention is obtained by molding the polyolefin fat composition of the present invention.
As the molding method, a known molding method can be used, and examples thereof include extrusion molding, injection molding, calendar molding, blow molding, thermoforming, foam molding, vacuum molding, and melt spinning.

  Since the molded body of the present invention is excellent in slidability and scratch resistance on the surface of the molded body, it is suitable for automobile members, household appliance members, medical members, and building members.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
In the examples, “parts” and “%” indicate “parts by mass” and “% by mass”.

(1) Sliding property About the obtained molded object, the dynamic friction coefficient was measured on the following measurement conditions in the atmosphere of room temperature 23 degreeC, and humidity 50%, and the following reference | standard evaluated.
Load: 30N
Travel speed: 2mm / min
Measuring distance: 10cm
Number of reciprocations: 30 times Note that the dynamic friction coefficient (μ) is a representative evaluation value indicating the slidability of the molded body obtained by the following formula. The smaller the value, the higher the slidability.
μ = f × r / L × R [−]
μ: Coefficient of dynamic friction f: Friction force detected by load cell R: Sample average radius r: Load center length L: Load <Evaluation criteria>
◎: Dynamic friction coefficient is 0.1 or less ○: Dynamic friction coefficient is greater than 0.1, 0.2 or less △: Dynamic friction coefficient is greater than 0.2, 0.25 or less ×: Dynamic friction coefficient is greater than 0.25

(2) Scratch resistance The state of the test after the above slidability evaluation was visually confirmed and evaluated according to the following criteria.
<Evaluation criteria>
○: Almost no scratch △: Scratch can be confirmed if fully confirmed ×: Clear scratch can be confirmed

(3) Bending elastic modulus About the obtained molded object, the bending elastic modulus was measured according to JIS K-7171. In addition, a molded object is a molded object of length: 80mm, thickness: 10mm, and width: 4mm.

(4) Volume average particle diameter (dv)
A latex containing particles is diluted with distilled water to prepare 0.1 mL of a diluted latex sample having a concentration of about 3%, and a capillary type particle size distribution analyzer (CHDF2000 type (trade name), manufactured by MATEC (USA)) is used. The volume average particle diameter (dv) was measured. The measurement conditions were a flow rate of 1.4 mL / min, a pressure of about 2.76 MPa (about 4,000 psi), and a temperature of 35 ° C. For the measurement, a capillary cartridge for particle separation and a carrier liquid were used, and the liquidity was made almost neutral. Before the measurement, a standard curve was prepared by measuring monodisperse polystyrene having a known particle size (manufactured by DUKE (USA)) as a standard particle size substance and measuring the particle size at a total of 12 points of 20 to 800 nm. Regarding the volume average particle diameter (dv), the analysis value in the volume distribution of the particle diameter measurement result was defined as the volume average particle diameter (dv).
(5) Toluene-insoluble content 0.5 g of the polyorganosiloxane-containing graft copolymer (a) was precisely weighed, immersed in 80 mL of toluene at room temperature for 24 hours, centrifuged at 12,000 rpm for 60 minutes, and separated poly The organosiloxane-containing graft copolymer (a) was weighed again to calculate the mass fraction (% by mass) of the toluene insoluble matter.

<Preparation of test piece for evaluation of slidability and scratch resistance>
Hand blended slidability improver (A) and “NOVATEC PP FY-4” (trade name, Homopolypropylene MFR = 5 g / 10 min manufactured by Nippon Polypro Co., Ltd.) as polyolefin resin (B) at the ratios shown in Table 21 Then, using a φ30 mm same-direction twin screw extruder (model name “BT-30” manufactured by Plastic Engineering Laboratory, L / D = 30), screw rotation speed: 200 rpm, cylinder temperature: 200 ° C. A polyolefin resin composition was obtained under the following conditions. The resulting polyolefin resin composition was subjected to a 100t injection molding machine (model name “SE-100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under conditions of molding temperature: 200 ° C., mold temperature: 80 ° C. A molded body having a thickness of 100 mm, a height of 100 mm, and a thickness of 3 mm was produced and used for evaluation.

<Creation of test specimen for bending elastic modulus evaluation>
A polyolefin resin composition was obtained in the same manner as the above test piece for slidability evaluation. The obtained polyolefin resin composition was long using a 100t injection molding machine (model name “SE-100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under conditions of molding temperature: 200 ° C. and mold temperature: 80 ° C. A molded body having a thickness of 80 mm, a thickness of 10 mm, and a width of 4 mm was prepared and subjected to evaluation of the flexural modulus.

<Production of polyorganosiloxane-containing graft copolymer>
[Production Example 1 Production of Polyorganosiloxane-Containing Graft Copolymer (a-1)]
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. 100 parts of the above siloxane mixture is added to 200 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of dodecylbenzenesulfonic acid are dissolved. An organosiloxane latex was obtained by emulsifying and dispersing under pressure. The mixture 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, left at 20 ° C., and after 48 hours, the latex was washed with 5% aqueous sodium hydroxide solution. The pH was neutralized to 7.4, polymerization was completed, and polyorganosiloxane latex (S-1) was obtained. The obtained polyorganosiloxane had a volume average particle size of 160 nm.

243 parts (81 parts as polyorganosiloxane) of the above polyorganosiloxane latex (S-1) were collected, placed in a separable flask equipped with a stirrer, 100 parts of distilled water was added, and the atmosphere was replaced with nitrogen. The temperature was raised to 0 ° C., and a mixture of 8.9 parts of n-butyl acrylate, 0.1 part of allyl methacrylate and 0.56 part of tert-butyl hydroperoxide was added and stirred for 30 minutes. The siloxane particles were infiltrated. Next, a mixture of ferrous sulfate (0.002 parts), ethylenediaminetetraacetic acid disodium salt (0.006 parts), Rongalite (0.26 parts) and distilled water (5 parts) was charged to initiate radical polymerization. The polymerization was completed by maintaining at a temperature of 70 ° C. for 2 hours to obtain a polyorganosiloxane / n-butyl acrylate composite rubber latex. A part of this latex was sampled and the volume average particle diameter of a polyorganosiloxane / n-butyl acrylate composite rubber (hereinafter also simply referred to as “composite rubber”) was measured and found to be 220 nm.

A mixture of 0.06 part of tert-butyl hydroperoxide and 10 parts of methyl methacrylate was added dropwise to the composite rubber latex over 15 minutes at 70 ° C., and then kept at 70 ° C. for 4 hours to graft onto the composite rubber. The polymerization was complete. The obtained graft copolymer latex is appropriately placed in 200 parts of hot water of 1.5% calcium chloride, coagulated, separated, washed, dried at 75 ° C. for 16 hours, and powdered polyorganosiloxane / n. A butyl acrylate composite rubber-containing graft copolymer (a-1) was obtained. This was designated as a slidability improver (A-1).

[Production Example 2 Production of Polyorganosiloxane-Containing Graft Copolymer (a-2)]
2 parts of tetraethoxysilane, 2 parts of γ-methacryloyloxypropyldimethoxymethylsilane, and 96 parts of octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane mixture. Add 100 parts of the above siloxane mixture to 150 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate is dissolved, pre-stir at 10,000 rpm with a homomixer, and then emulsify and disperse with a homogenizer at a pressure of 300 kg / cm @ 2. An organosiloxane latex was obtained.
Subsequently, the mixture was transferred to a separable flask equipped with a condenser and a stirring blade, and after the organosiloxane latex was heated to 80 ° C., a mixture of 0.2 part of sulfuric acid and 49.8 parts of distilled water was continuously added over 3 minutes. I put it in. The polymerization reaction was carried out while maintaining the temperature at 80 ° C. for 7 hours, and then cooled to 25 ° C. and held for 6 hours. Then, it neutralized until it became pH 7.0 with 5% sodium hydroxide aqueous solution, and polyorganosiloxane rubber latex (S-2) was obtained. The obtained polyorganosiloxane had a volume average particle size of 400 nm.

Collect 30 parts of the polyorganosiloxane latex (10 parts as polyorganosiloxane), put it in a separable flask equipped with a stirrer, add 200 parts by weight of distilled water, purge with nitrogen, and then raise the temperature to 50 ° C. Then, a mixed solution of 59.1 parts of n-butyl acrylate, 0.9 part of allyl methacrylate and 1.8.18 parts of tert-butyl hydroperoxide was added and stirred for 30 minutes. Infiltrated. Next, radical polymerization was carried out by adding a mixed solution of 0.010.001 parts of ferrous sulfate, 0.030.003 parts of disodium ethylenediaminetetraacetate, 1.80.18 parts of Rongalite and 5 parts of distilled water. Thereafter, the internal temperature was held at 65 ° C. for 2 hours to complete the polymerization to obtain a composite rubber latex. A part of this latex was sampled, and the volume average particle diameter of the composite rubber was measured and found to be 420 nm.

Further, with the composite rubber latex kept at 65 ° C., a mixed solution of 30 parts of methyl methacrylate and 0.14 part of tert-butyl hydroperoxide was dropped into the flask over 1 hour. After completion of the dropping, the temperature of 65 ° C. was maintained for 1 hour to complete the graft polymerization onto the composite rubber.

The obtained graft copolymer latex is appropriately placed in 200 parts of hot water of 1.5% calcium chloride, coagulated, separated, washed, dried at 75 ° C. for 16 hours, and powdered polyorganosiloxane rubber / An n-butyl acrylate composite rubber-containing graft copolymer (a-2) was obtained. This was designated as a slidability improver (A-2).

[Production Example 3 Production of Polyorganosiloxane-Containing Graft Copolymer (a-3)]
241 parts of polyorganosiloxane latex (S-1) described in Production Example 1 (80 parts as polyorganosiloxane) is collected, placed in a separable flask equipped with a stirrer, 100 parts of distilled water is added, and nitrogen substitution is performed. Then, the temperature was raised to 50 ° C., a mixed solution of 3.0 parts of allyl methacrylate and 0.2 part of tert-butyl hydroperoxide was added and stirred for 30 minutes, and this mixed solution was permeated into the polyorganosiloxane particles. . Next, a mixture of 0.001 part of ferrous sulfate, 0.003 part of disodium ethylenediaminetetraacetate, 0.26 part of Rongalite and 5 parts of distilled water was charged to initiate radical polymerization, The temperature was maintained at 70 ° C. for 2 hours to complete the polymerization to obtain a composite rubber latex. A part of this latex was sampled, and the volume average particle diameter of the composite rubber was measured and found to be 190 nm.
To the above composite rubber latex, a mixture of 0.12 part of tert-butyl hydroperoxide, 17 parts of methyl methacrylate and 2 parts of n-butyl acrylate was added dropwise at 70 ° C. over 15 minutes, and then 4 ° C. at 70 ° C. Holding for a time, the graft polymerization onto the composite rubber was completed. The obtained graft copolymer latex is appropriately placed in 200 parts of hot water of 1.5% calcium chloride, coagulated, separated, washed and then dried at 75 ° C. for 16 hours to contain a powdered polyorganosiloxane rubber. A graft copolymer (a-3) was obtained. This was designated as a slidability improver (A-3).

Table 1 summarizes the composition and evaluation results of the slidability improvers “A-1” to “A-3”.

n-BA: n-butyl acrylate AMA: allyl methacrylate MMA: methyl methacrylate

[Example 1]
As the slidability improver (A), 1 part of the above (A-1) and 99 parts of polypropylene resin “Novatech FY-4” (trade name, manufactured by Nippon Polypro Co., Ltd.) as the polyolefin resin were mixed. Extrusion was performed under the conditions of a screw rotation speed of 200 rpm and a cylinder temperature of 200 ° C. using a φ30 mm same-direction twin screw extruder (manufactured by Plastic Engineering Laboratory Co., Ltd., L / D = 30) to obtain a polyolefin resin composition. The obtained thermoplastic resin composition was dried at 80 ° C. for 12 hours, and the molded article for evaluation was molded with an injection molding machine (model name “SE-100DU”, manufactured by Sumitomo Heavy Industries, Ltd.). About the obtained molded object, the slidability, scratch resistance, and bending elastic modulus were evaluated by the above evaluation methods. The evaluation results are shown in Table 21.

[Example 2]
Except having changed the quantity of the slidability improving agent (A-1) to 5 parts, it compounded and shape | molded by the method similar to Example 1, and evaluated. The results are shown in Table 21.

[Example 3]
Except having changed the quantity of the slidability improving agent (A-1) to 30 parts, it compounded and molded by the method similar to Example 1, and evaluated. The results are shown in Table 21.

[Example 4]
The slidability improver (A) was changed to (A-2), and the amount was changed to the ratio described in Table 21, and then compounded and molded in the same manner as in Example 1 for evaluation. The results are shown in Table 21.

[Example 5]
Evaluation was performed by blending and molding in the same manner as in Example 2 except that 20 parts of talc (“Talc MS” manufactured by Nippon Talc Co., Ltd.) was added as a filler. The results are shown in Table 21.

[Example 6]
Evaluation was performed by blending, molding, and molding in the same manner as in Example 2 except that 20 parts of calcium carbonate (“Shirakaka CC-R” manufactured by Shiroishi Kogyo Co., Ltd.) was added as a filler. The results are shown in Table 21.

[Example 7]
The slidability improver (A) was changed to (A-3), and the amount was changed to the ratio shown in Table 2, and then compounded and molded in the same manner as in Example 1 for evaluation. The results are shown in Table 2.

[Example 8]
Except having changed the quantity of the slidability improvement agent (A-3) into 5 parts, it mix | blended and shape | molded by the method similar to Example 7, and evaluated. The results are shown in Table 2.
[Example 9]
Evaluation was carried out by blending and molding in the same manner as in Example 2 except that the polyolefin resin was changed to the polyethylene resin “Novatec HD HJ-362N” (trade name, manufactured by Nippon Polyethylene Co., Ltd.). The results are shown in Table 2.

[Comparative Example 1]
Except that the slidability improver (A) was not added, evaluation was carried out by blending and molding in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 2]
Except that the slidability improver (A) was not added, evaluation was carried out by blending and molding in the same manner as in Example 5. The results are shown in Table 2.

[Comparative Example 3]
Except that the slidability improver (A) was not added, evaluation was carried out by blending and molding in the same manner as in Example 6. The results are shown in Table 2.

PP: Novatec PP FY-4 manufactured by Nippon Polypro Co., Ltd.
PE: Novatec HD HJ-362N manufactured by Nippon Polyethylene Co., Ltd.
Talc: Talc MS manufactured by Nippon Talc Co., Ltd.
Carbonated Ca: White Shiraka CC-R manufactured by Shiroishi Kogyo Co., Ltd.

As is apparent from Table 2, the molded product containing the slidability improver (A) of the present invention can reduce the coefficient of dynamic friction and improve the slidability without greatly changing the elastic modulus. Further, along with the improvement of the slidability, the scratch resistance is also improved. On the other hand, Comparative Examples 1 to 3 which do not contain the slidability improver (A) of the present invention have low slidability and scratch resistance.
From the above, it is clear that the slidability of the obtained molded product can be improved by using the slidability improver (A) of the present invention.

  By using the slidability improver of the present invention, it is possible to improve the slidability and scratch resistance of the polyolefin resin molded body, automotive members, household appliance members, medical members, building members, sheet materials, film materials, It is suitable for etc.

Claims (12)

  A slidability improver (A) for polyolefin resin comprising a rubber-containing graft copolymer (a) obtained by grafting one or more kinds of vinyl monomers to rubber containing polyorganosiloxane.   The slidability improver (A) for polyolefin resin according to claim 1, wherein the toluene-insoluble content of the rubber-containing graft copolymer (a) is 10% by mass or more.   The slidability improver (A) for polyolefin resins according to claim 1 or 2, wherein the rubber containing polyorganosiloxane is a rubber comprising polyorganosiloxane.   The slidability improver (A) for polyolefin resins according to claim 1 or 2, wherein the rubber containing polyorganosiloxane is a composite rubber containing polyorganosiloxane and polyalkyl (meth) acrylate.   The slidability improver for polyolefin resin (A) according to any one of claims 1 to 4, wherein the content of the polyorganosiloxane in the rubber-containing graft copolymer (a) is 10 to 95% by mass.   A polyolefin resin composition comprising the slidability improver (A) for polyolefin resin according to any one of claims 1 to 5 and a polyolefin resin (B).   The polyolefin according to claim 6, wherein the content of the slidability improver (A) for polyolefin resin is 0.1 to 40% by mass (provided that the total of (A) and (B) is 100% by mass). Resin composition. The polyolefin according to claim 6, wherein the content of the slidability improver (A) for polyolefin resin is 0.1 to 7% by mass (provided that the total of (A) and (B) is 100% by mass). Resin composition.   The polyolefin resin composition according to any one of claims 6 to 8, wherein the polyolefin resin (B) is polypropylene.   Furthermore, the polyolefin resin composition of any one of Claims 6-9 containing a filler (C).   The polyolefin resin composition according to claim 10, wherein the filler (C) is talc, calcium carbonate, or mica.   The molded object formed by shape | molding the polyolefin resin composition of any one of Claims 6-11.