JPH1149832A - Compression set reducing agent and resin containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an additive capable of providing a product improved in elasticity and compression set, having excellent processability, by subjecting a vinyl-based monomer to graft polymerization onto a complex rubber composed of a polyorganosiloxane and a polyalkyl (meth)acrylate. SOLUTION: This composition comprises a complex rubber-based graft copolymer obtained by subjecting (C) one or more vinyl-based monomers (methyl methacrylate) to graft polymerization onto a complex rubber which comprises (A) 1-99 wt.%, preferably 30-95 wt.% of a polyorganosiloxane (various cyclic substances of preferably 3 to 6-membered substances such as hexamethylcyclotrisiloxane may be cited as the organosiloxane) and (B) 99-1 wt.% of a polyalkyl (meth)acrylate and is preferably obtained by preparing a latex of the polyorganosiloxane and impregnating a synthetic monomer of an alkyl (meth)acrylate to particles of the polyorganosiloxane latex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a compression set reducing agent excellent in weather resistance and a soft resin composition containing the same.

[0002]

2. Description of the Related Art The demand for improved performance of soft resins is increasing year by year. Particularly in the field of automobiles, as materials for glass run channels, drainers, flash mount moldings, etc., they have excellent weather resistance, excellent elastic recovery and low elasticity. It is required to exhibit compression set.

Conventionally, soft vinyl chloride resins as these materials have a soft rubber-like feel, are superior in moldability, weather resistance, and coloring properties as compared with vulcanized rubber, and also from the viewpoint of cost,
It has been used extensively. However, there are problems that the material becomes brittle at a low temperature and that the compression set is inferior to that of vulcanized rubber. Attempts have been made to improve the vinyl chloride resin by replacing it with a higher degree of polymerization, but no satisfactory resin has been obtained.

Further, nitrile rubber (N
(BR rubber) has been proposed to improve the compression set, but these compositions tend to have poor weather resistance.

Further, Japanese Patent Application Laid-Open No. Hei 4-335047,
Japanese Patent Application Laid-Open No. 5-1187 discloses that a blend of chlorinated polyethylene and a plasticizer improves compression set and weather resistance, but has a practical problem of embrittlement at low temperatures. is there.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to have excellent workability which does not delay melt dispersion during kneading, and to obtain an elastic material based on a temperature difference due to seasonal fluctuation. Small change, imparts the ability to recover elasticity at the time of installation after bending storage, and also exhibits excellent elasticity over a long period of time even after the product, that is, shows rubber elasticity in a wide temperature range, and has a small compression set And a soft resin composition obtained by blending the additive.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that a composite rubber comprising a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate component has at least one or more types of composite rubber. When the soft permanent resin (B) is blended with the compression set (A), which is mainly composed of a composite rubber-based graft copolymer obtained by graft-polymerizing a vinyl monomer, it does not delay melt dispersion during kneading. What is excellent in processability, the one obtained by processing shows rubber elasticity over a wide temperature range, and is excellent in reducing compression set,
Further, it was found that the weather resistance was excellent.

That is, the gist of the present invention is as follows.
Compression permanent distortion reducing agent (A) comprising a composite rubber-based graft copolymer obtained by graft-polymerizing one or more vinyl monomers onto a composite rubber comprising a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate component And a soft resin composition containing the same.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The compression set reducing agent (A) used in the present invention is a composite rubber comprising a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate component, wherein one or more vinyl monomers are added to the composite rubber. It consists of a graft-polymerized copolymer.

In place of the above composite rubber, Japanese Patent Publication No. 7-58
No. 08 described in Japanese Patent Application Laid-Open Publication No. 08-0838, even if any one of a non-crosslinked polyorganosiloxane, a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate component or a simple mixture thereof is used as a rubber source, The resin composition having excellent processability and low compression set can be obtained only when the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate component are combined and integrated without obtaining the characteristics possessed.

[0012] The two components constituting the composite rubber are 1 to 99% by weight of a polyorganosiloxane rubber component and 99 to 1% by weight of a polyalkyl (meth) acrylate component (however, the total amount of both components is 100% by weight). %), From the viewpoint of compression set, the polyorganosiloxane rubber component is more preferably in the range of 30 to 95% by weight, and even more preferably 50 to 90% by weight.

The above-mentioned composite rubber may be produced by any method, but the emulsion polymerization method is most suitable. First, a latex of polyorganosiloxane is prepared, and then a monomer for the synthesis of alkyl (meth) acrylate is prepared. Is preferably impregnated into particles of a polyorganosiloxane latex, and then the synthesis monomer is polymerized.

The polyorganosiloxane rubber component constituting the composite rubber can be prepared by emulsion polymerization using the following organosiloxane and a crosslinking agent (CI). At this time, a graft crosslinking agent (GI) is further added. They can be used together.

Examples of the organosiloxane include various cyclic bodies having three or more membered rings, and the preferred one is the three-membered ring.
A 6-membered ring. For example, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, and the like, These may be used alone or in combination of two or more. These are used in an amount of 5% in the polyorganosiloxane component.
It is at least 0% by weight, preferably at least 70% by weight.

As the crosslinking agent (CI), trifunctional or tetrafunctional silane crosslinking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, Tetrabutoxysilane or the like is used. Particularly, a tetrafunctional crosslinking agent is preferable, and among them, tetraethoxysilane is particularly preferable. The amount of the crosslinking agent used is 0.1 to 30% by weight in the polyorganosiloxane component.

As the graft-linking agent (GI), a compound capable of forming a unit represented by the following formula is used.

[0018] ^{_{CH 2 = C (R 2)}} -COO (CH) P -SiR 1 n O (3-n) / 2 (GI-1) CH 2 = C (R 2) -C 6 H 4 -SiR 1 _{n O (3-n) /} 2 (GI-2) CH 2 = CH-SiR 1 n O (3-n) / 2 (GI-3) HS- (CH) P -SiR 1 n O (3-n _{) / 2} (GI-4) (wherein, R ¹ is a methyl group, an ethyl group, a propyl group, or a phenyl group, R ² is a hydrogen atom or a methyl group, n is 0, 1 or 2, and p is 1 to 3.) An integer of 6 is shown.) The (meth) acryloyloxysiloxane capable of forming the unit of the above formula (GI-1) has a high grafting efficiency and can form an effective graft chain, and exhibits impact resistance. It is advantageous in the point.

Incidentally, methacryloyloxysiloxane is particularly preferred as a compound capable of forming the unit of the above formula (GI-1). Specific examples of methacryloyloxysiloxane include β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyl Examples thereof include ethoxydiethylsilane, γ-methacryloyloxypropyldiethoxymethylsilane, and γ-methacryloyloxybutyldiethoxymethylsilane.

Examples of the unit capable of forming the unit of the above formula (GI-2) include vinylsiloxane, and specific examples include tetramethyltetravinylcyclotetrasiloxane.

One which can form the unit of the above formula (GI-3) is p-vinylphenyldimethoxymethylsilane. Examples of the unit capable of forming the unit of the formula (GI-4) include γ-mercaptopropyldimethoxymethylsilane, γ-mercaptopropylmethoxydimethylsilane, and γ-mercaptopropyldiethoxymethylsilane.

The amount of the grafting agent used is 0 to 10% by weight, preferably 0.5 to 5% by weight, based on the polyorganosiloxane component.

The latex of the polyorganosiloxane component can be produced by the method described in, for example, US Pat. Nos. 2,891,920 and 3,294,725. In the practice of the present invention, for example, a mixed solution of an organosiloxane and a crosslinking agent (CI) and, if desired, a graft crosslinking agent (GI) are mixed with a homogenizer in the presence of a sulfonic acid emulsifier such as alkylbenzenesulfonic acid or alkylsulfonic acid. It is preferable to produce by a method of shear-mixing with water using the method described above.
Alkylbenzene sulfonic acid is suitable because it acts as an emulsifier for the organosiloxane and also serves as a polymerization initiator. At this time, it is preferable to use a metal salt of an alkyl benzene sulfonic acid, a metal salt of an alkyl sulfonic acid or the like in combination, since this is effective for stably maintaining the polymer during graft polymerization.

Next, the polyalkyl (meth) acrylate component constituting the composite rubber can be synthesized using the following alkyl (meth) acrylate, cross-linking agent (CII) and graft-crossing agent (GII). .

As the alkyl (meth) acrylate,
For example, methyl acrylate, ethyl acrylate, n-
Propyl acrylate, n-butyl acrylate, 2-
Examples thereof include alkyl acrylates such as ethylhexyl acrylate and alkyl methacrylates such as hexyl methacrylate, 2-ethylhexyl methacrylate and n-lauryl methacrylate, and the use of n-butyl acrylate is particularly preferable.

Examples of the crosslinking agent (CII) include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and 1,4-butylene glycol dimethacrylate.

Examples of the graft crossing agent (GII) include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate and the like. Allyl methacrylate can also be used as a crosslinking agent. These crosslinking agents and graft crossing agents are used alone or in combination of two or more. The total amount of the crosslinking agent and the grafting agent used is 0.1 to 20% by weight in the polyalkyl (meth) acrylate component.

The polymerization of the polyalkyl (meth) acrylate component is carried out by adding the above-mentioned alkyl (meth) acrylate into a latex of a polyorganosiloxane component that has been neutralized by adding an aqueous solution of an alkali such as sodium hydroxide, potassium hydroxide or sodium carbonate. After adding a crosslinking agent and a graft-linking agent to impregnate the polyorganosiloxane particles, the reaction is carried out by the action of a usual radical polymerization initiator. As the polymerization proceeds, a composite rubber latex of the polyorganosiloxane component and the polyalkyl (meth) acrylate component is obtained. In the practice of the present invention, as the composite rubber, the main skeleton of the polyorganosiloxane rubber component has a repeating unit of dimethylsiloxane, and the main skeleton of the polyalkyl (meth) acrylate component has a repeating unit of n-butyl acrylate. Composite rubber is preferably used.

The composite rubber thus prepared by emulsion polymerization can be graft-copolymerized with a vinyl monomer, and the polyorganosiloxane rubber component and the polyalkyl (meth) acrylate component can be prepared from acetone, toluene or the like. Extraction and separation cannot be performed with ordinary organic solvents. The gel content measured by extracting the composite rubber with toluene at 90 ° C. for 12 hours is 80% by weight or more.

Examples of vinyl monomers to be graft-polymerized on the composite rubber include aromatic alkenyl compounds such as styrene, α-methylstyrene and vinyltoluene; methacrylic esters such as methyl methacrylate and 2-ethylhexyl methacrylate; methyl acrylate; Acrylic esters such as ethyl acrylate and n-butyl acrylate; and various vinyl monomers such as vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, which may be used alone or in combination of two or more. Of these vinyl monomers, methacrylates are preferred, and methyl methacrylate is particularly preferred.

The compounding amount of the compression set reducing agent (A) used in the present invention is 1 to 2000 parts by weight, preferably 5 to 100 parts by weight, more preferably 100 parts by weight of the soft resin (B). It is in the range of 10 to 50 parts by weight.

The ratio of the composite rubber to the vinyl monomer in the compression set reducing agent (A) is 5 to 95% by weight, preferably 25 to 90% by weight, based on the weight of the graft copolymer. % By weight and 5 to 95 vinyl monomers
%, Preferably 10 to 75% by weight. If the amount of the vinyl monomer is less than 5% by weight, the dispersibility of the graft copolymer in the resin composition will be poor, and if it exceeds 95% by weight, the compression set will be significantly reduced.

The compression set reducing agent (A) can be obtained by adding the above-mentioned vinyl monomer to the latex of the composite rubber and polymerizing it in one or more stages by a radical polymerization technique. The graft copolymer latex can be preferably separated and recovered by putting it into hot water in which a metal salt such as calcium chloride, calcium acetate or magnesium sulfate is dissolved, salting out and coagulating.

The soft resin (B) used in the present invention is not particularly limited, and it is conventionally known, styrene elastomer, olefin elastomer containing chlorinated polyethylene, urethane elastomer, polyester elastomer, polyamide elastomer. , A fluorine-based elastomer, 1,2-polybutadiene, trans 1,4-polyisoprene, a vinyl chloride-based elastomer containing a soft vinyl chloride resin, and the like, but may be used alone or in combination.

In addition, as long as the soft resin (B) is included and exhibits softness, other resins such as olefin resin (olefin resin) such as polypropylene (PP) and polyethylene (PE), polystyrene ( P
S), high impact polystyrene (HIPS), (meth) acrylate / styrene copolymer (MS),
Styrene / acrylonitrile copolymer (SAN), styrene / maleic anhydride copolymer (SMA), ABS, A
Styrene-based resins (St-based resins) such as SA and AES,
Acrylic resin (Ac resin) such as polymethyl methacrylate (PMMA), polycarbonate resin (PC resin), polyamide resin (PA resin), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. Polyester resin (PEs resin), (modified) polyphenylene ether resin (PPE)
Resin), polyoxymethylene resin (POM resin), polysulfone resin (PSO resin), polyarylate resin (PAr resin), polyphenylene resin (PPS resin), thermoplastic polyurethane resin ( P
Engineering plastics such as U-based resin), PC-based resin such as PC / ABS / St-based resin alloy, PVC-based resin such as PVC / ABS / St-based resin alloy, PA-based resin such as PA / ABS / St. -Based resin alloy, PA-based resin such as PA / PP / polyolefin-based resin alloy, PC-based resin such as PC / PBT / PEs-based resin alloy, alloy of olefin-based resins such as PP / PE, PPE / HIPS, PPE / PBT, PPE /
It can be used together with a polymer alloy such as a PPE resin alloy such as PA and a PVC resin / Ac resin alloy such as PVC / PMMA.

Particularly, as the soft resin (B), a composition comprising a vinyl chloride resin and / or a chlorinated polyethylene (B-1) and a plasticizer (B-2) is preferable.

Examples of the vinyl chloride resin include a vinyl chloride homopolymer, a post-chlorinated vinyl chloride polymer, a partially crosslinked vinyl chloride polymer, and a copolymer of a monomer copolymerizable with vinyl chloride. Any of the above can be selected and used.

Examples of monomers copolymerizable with vinyl chloride include vinyl esters of fatty acids such as vinyl acetate, vinyl propionate and vinyl laurate, methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate. (Meth) acrylic acid alkyl ester such as acrylate, acrylonitrile, vinyl cyanide such as methacrylonitrile, alkyl vinyl ether such as vinyl methyl ether, vinyl butyl ether, α-olefin such as ethylene, propylene, styrene, acrylic acid, methacrylic acid, Examples include unsaturated carboxylic acids such as maleic anhydride or acid anhydrides thereof, vinylidene chloride, vinyl bromide, various urethanes, and the like. These may be used alone or in combination of two or more. Among such copolymers, particularly preferred are vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene-vinyl acetate terpolymer,
Vinyl chloride-acrylic acid copolymer, and vinyl chloride-
Urethane copolymers are exemplified.

These vinyl chloride resins may be used alone or in combination of two or more. The average degree of polymerization is not particularly limited.
It is preferably in the range of 00 to 10,000, and those having different average polymerization degrees may be appropriately blended and used. If the average degree of polymerization is less than 700, sufficient elastic recovery cannot be obtained, and if it exceeds 10,000, processability tends to decrease.

The chlorinated polyethylene is not particularly limited, but has a chlorination degree of 20 to 45% and a chlorination degree of 10 to 45%.
It is preferable that the crystal has a heat of fusion of 5 to 35 cal / g by a DSC method (differential scanning calorimetry) at a heating rate of ° C./min. If the chlorination degree is less than 20%, the compatibility with the plasticizer decreases and the hardness cannot be reduced. If the chlorination degree exceeds 45%, the rubber elasticity decreases, and if the heat of crystal fusion becomes less than 5 cal / g, the resin becomes soft. Cannot maintain its form as 3
If it exceeds 5 cal / g, the hardness cannot be reduced, and the workability also decreases.

The plasticizer (B-2) used in the present invention is not particularly limited, and can be arbitrarily selected from those conventionally used for vinyl chloride resins. For example, alkyl esters of aromatic polybasic acids such as dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate, diisononyl phthalate, diundecyl phthalate, trioctyl trimellitate, triisooctyl trimellitate, and pyromet, dibutyl adipate, dioctyl adipate, dicynonyl adipate Polyesters such as alkyl esters of fatty acid polybasic acids such as phosphate, dibutyl azelate, dioctyl azelate and diisononyl azelate; phosphate esters such as tricresyl phosphate; adipic acid, azelaic acid, sebacic acid and phthalic acid Carboxylic acid and ethylene glycol, 1,2
A molecular weight of 600 to 8, with a polyhydric alcohol such as propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol;
Polyester plasticizers such as those having the ends of polycondensates of about 000 sealed with monohydric alcohols or monocarboxylic acids, epoxidized soybean oil, epoxidized linseed oil, epoxidized tall oil fatty acid-2-ethylhexyl, etc. Epoxy plasticizers, chlorinated paraffins and the like can be mentioned.

These plasticizers may be used alone or in combination of two or more. Among them, a phthalic acid-based plasticizer such as dioctyl phthalate or isononyl phthalate is used, and the above-mentioned vinyl chloride-based resin has a high polymerization degree. Is preferable because bleeding is small.

The amount of the plasticizer (B-2) is such that the plasticizing effect is exhibited, the elasticity and elongation of the obtained molded product are sufficient, and the hardness is not too high. Although not particularly limited, mechanical properties such as abrasion resistance tend to decrease when the content is too large, and usually 5 to 200 parts by weight based on 100 parts by weight of a vinyl chloride resin and / or chlorinated polyethylene. , Preferably 10-12
0 parts by weight, more preferably 30 to 90 parts by weight.

To the resin composition of the present invention, conventional stabilizers and fillers may be added at the time of compounding, kneading and molding the resin according to the purpose, as long as the physical properties are not impaired. Can be.

Examples of the stabilizer include lead-based stabilizers such as tribasic lead sulfate, dibasic lead phosphite, basic lead sulfite, lead silicate, potassium, magnesium, barium, and the like.
Metals such as zinc, cadmium and lead and 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, hydroxystearic acid,
Oleic acid, ricinoleic acid, linoleic acid, metal soap-based stabilizer derived from fatty acids such as behenic acid, alkyl group, ester group and fatty acid salt, maleate, organotin-based stabilizer derived from sulfide-containing, Ba-Zn system, Ca-
Zn-based, Ba-Ca-Sn-based, Ca-Mg-Sn-based, C
a-Zn-Sn-based, Pb-Sn-based, Pb-Ba-Ca-based composite metal soap-based stabilizers, metal groups such as barium, zinc, and branched fatty acids such as 2-ethylhexanoic acid, isodecanoic acid, and trialkylacetic acid; It is usually derived from two or more organic acids such as unsaturated fatty acids such as oleic acid, ricinoleic acid and linoleic acid, aliphatic acids such as naphthenic acid, and aromatic acids such as carboxylic acid, benzoic acid, salicylic acid, and substituted derivatives thereof. Metal salt stabilizers, and these stabilizers are dissolved in organic solvents such as petroleum hydrocarbons, alcohols, and glycerin derivatives, and further phosphites, epoxy compounds, color inhibitors, transparency improvers, light stabilizers, In addition to metal-based stabilizers such as metal salt liquid stabilizers that contain stabilizing aids such as antioxidants, plate-out inhibitors, and lubricants, epoxy resins and epoxy resins Epoxy compounds such as xylated soybean oil, epoxidized vegetable oil, and epoxidized fatty acid alkyl ester; phosphorus in which alkyl, aryl, cycloalkyl, and alkoxyl groups are substituted; dihydric alcohols such as propylene glycol; hydroquinone; A, an organic phosphite having an aromatic compound such as, hindered phenol such as bisphenol dimerized with BHT or sulfur or a methylene group, an ultraviolet absorber such as salicylate, benzophenone, benzotriazole, a hindered amine or Nickel complex salt light stabilizer, carbon black, UV shielding agent such as rutile type titanium oxide, polyhydric alcohol such as trimerol propane, pentaerythritol, sorbitol, mannitol, β-aminocrotonate Nitrogen, nitrogen-containing compounds such as 2-phenylindole, diphenylthiourea and dicyandiamide; sulfur-containing compounds such as dialkylthiodipropionate; keto compounds such as acetoacetate, dehydroacetic acid and β-diketone; organosilicon compounds; borate And the like, and these are used alone or in combination of two or more.

Examples of the filler include carbonates such as heavy calcium carbonate, precipitated calcium carbonate and colloidal calcium carbonate, titanium oxide, clay, talc, mica, silica, carbon black, graphite, glass beads, and the like.
Examples include inorganic fibers such as glass fibers, carbon fibers, and metal fibers, organic fibers such as polyamide, organic materials such as silicone, and natural organic materials such as wood flour.

In addition, MBS, ABS, AES, NB
Impact strength modifiers such as R, EVA, acrylic rubber, composite rubber graft copolymers, processing aids such as (meth) acrylate copolymers, liquid paraffin, pure hydrocarbons such as low molecular weight polyethylene, Halogenated hydrocarbons,
Fatty acids such as higher fatty acids, oxy fatty acids, fatty acid amides such as fatty acid amides, polyhydric alcohol esters of fatty acids such as glycerides, fatty alcohol esters of fatty acids (ester wax), metallic soaps, fatty alcohols,
Polyhydric alcohol, polyglycol, polyglycerol,
Ester such as partial ester of fatty acid and polyhydric alcohol, fatty acid and polyglycol, partial ester of polyglycerol, (meth) acrylate copolymer, etc.
These lubricants, chlorinated paraffin, aluminum hydroxide,
Flame retardants such as antimony trioxide and halogen compounds; heat-resistant improvers such as (meth) acrylate-based copolymers, imide-based copolymers, styrene-acrylonitrile-based copolymers, release agents, crystal nucleating agents, and fluids A property improving agent, a colorant, an antistatic agent, a conductivity-imparting agent, a surfactant, an antifogging agent, a foaming agent, an antibacterial agent, and the like can be added.

The method for producing the resin composition of the present invention is not particularly limited, and ordinary methods can be used satisfactorily. However, the melt mixing method is generally preferred. The use of small amounts of solvents is possible but generally not necessary. Examples of the apparatus include, in particular, an extruder, a Banbury mixer, a roller, a kneader, etc., which are operated batchwise or continuously. The order of mixing the components is not particularly limited.

[0049]

The present invention will be described in more detail with reference to the following examples and comparative examples. "Parts" in the description is "parts by weight"
Is shown.

Reference Example 1 Production of Composite Rubber Graft Copolymer (S-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 mixed siloxane was added to 200 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of dodecylbenzenesulfonic acid were dissolved, and 10,000 was mixed with a homomixer.
After pre-stirring at 300 rpm,
The mixture was emulsified and dispersed at a pressure of kg / cm ² to obtain an organosiloxane latex. This mixed solution was transferred to a separable flask equipped with a condenser and a stirring blade, heated at 80 ° C. for 5 hours while mixing and stirring, and allowed to stand at 20 ° C.
After 8 hours, the pH of this latex was neutralized to 7.4 with an aqueous sodium hydroxide solution to complete the polymerization, thereby obtaining a polyorganosiloxane latex. The polymerization rate of the obtained polyorganosiloxane was 89.5%, and the average particle size of the polyorganosiloxane was 0.16 μm. This latex was coagulated and dried with isopropanol to obtain a solid, which was extracted with toluene at 90 ° C. for 12 hours. The gel content was measured and found to be 91.4% by weight.

268 parts of the above-mentioned polyorganosiloxane latex were put into a separable flask equipped with a stirrer, and 102 parts of distilled water was added.
And a mixture of 9.7 parts of n-butyl acrylate, 0.3 part of allyl methacrylate and 0.56 part of tert-butyl hydroperoxide was stirred and stirred for 30 minutes, and this mixture was permeated into the polyorganosiloxane particles. I let it. Then, a mixture of 0.002 part of ferrous sulfate, 0.006 part of disodium ethylenediaminetetraacetate, 0.26 part of Rongalit and 5 parts of distilled water was charged to start radical polymerization. After holding for a while, the polymerization was completed to obtain a composite rubber latex. A part of this latex was collected and the average particle diameter of the composite rubber was measured to be 0.22 μm. Further, this latex was dried to obtain a solid, which was extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured to be 97.3% by weight.

A mixture of 0.06 parts of tert-butyl hydroperoxide and 15 parts of methyl methacrylate was added dropwise to the composite rubber latex at 70 ° C. for 15 minutes, and then maintained at 70 ° C. for 4 hours to form a composite rubber latex. The graft polymerization of was completed. The polymerization rate of methyl methacrylate was 96.4%. The obtained graft copolymer latex was dropped into 200 parts of hot water containing 1.5% by weight of calcium chloride, coagulated, separated, washed, and dried at 75 ° C. for 16 hours to obtain a powdery composite rubber graft copolymer. 96.9 parts of the combined S-1 were obtained.

(Reference Example 2) Preparation of composite rubber-based graft copolymer (S-2, 3) Composite rubber-based graft copolymer S-2 was prepared in the same manner as in S-1 except for the charged composition shown in Table 1. , S-3.

Reference Example 3 Production of Acrylic Graft Copolymer (S-4) To a separable flask equipped with a stirrer, 295 parts of distilled water and 0.1 part of sodium dodecylbenzenesulfonate were added, and the mixture was purged with nitrogen. Then, the temperature was raised to 50 ° C., and 83.3 parts of n-butyl acrylate and 1.7 of allyl methacrylate were obtained.
And a mixture of 0.4 parts of tert-butyl hydroperoxide were charged and stirred for 30 minutes, and the mixture was permeated into the polyorganosiloxane particles. Then, sulfuric acid 1
A mixture of 0.002 part of iron, 0.006 part of disodium ethylenediaminetetraacetate, 0.26 part of Rongalit and 5 parts of distilled water was charged to start radical polymerization, and then kept at an internal temperature of 70 ° C. for 2 hours to carry out polymerization. Upon completion, a composite rubber latex was obtained. A part of this latex was collected and the average particle diameter of the composite rubber was measured to be 0.22 μm. Further, this latex was dried to obtain a solid, which was extracted with toluene at 90 ° C. for 12 hours, and the gel content was measured to be 97.3% by weight.

A mixture of 0.06 part of tert-butyl hydroperoxide and 15 parts of methyl methacrylate was added dropwise to this composite rubber latex at 70 ° C. for 15 minutes, and then kept at 70 ° C. for 4 hours to form a composite rubber latex. The graft polymerization of was completed.

The polymerization rate of methyl methacrylate is 97.
2%. The obtained graft copolymer latex was dropped into 200 parts of hot water containing 1.5% by weight of calcium chloride, coagulated, separated, washed, and dried at 75 ° C. for 16 hours.
A powdery acrylic graft copolymer S-4 was obtained.

(Reference Example 5) Production of polyorganosiloxane-based graft copolymer (S-5) Polyorganosiloxane latex 2 in Reference Example 1
85 parts of tert-butyl hydroperoxide 0.0
A mixture of 6 parts and 15 parts of methyl methacrylate was heated to 70 ° C.
For 15 minutes, and then kept at 70 ° C. for 4 hours to complete the graft polymerization to the composite rubber. The polymerization rate of methyl methacrylate was 97.4%. The obtained graft copolymer latex was treated with calcium chloride 1.5
It was dropped into 200 parts by weight of hot water of 200% by weight, coagulated, separated, washed, and dried at 75 ° C. for 16 hours to obtain a powdery polyorganosiloxane-based graft copolymer S-5.

Reference Example 6 Graft Copolymer (S-6)
Production of 0.5 part of γ-methacryloyloxypropyldimethoxymethylsilane and 99.5 parts of octamethylcyclotetrasiloxane were mixed to obtain 100 parts of a siloxane mixture. 100 parts of the above mixed siloxane was added to 200 parts of distilled water in which 1 part of sodium dodecylbenzenesulfonate and 1 part of dodecylbenzenesulfonic acid were respectively dissolved, and the mixture was preliminarily stirred at 10,000 rpm using a homomixer, and then 300 kg / cm ^{2 with} a homogenizer. Emulsified by pressure,
By dispersing, an organosiloxane latex was obtained. This mixed solution was transferred to a separable flask equipped with a condenser and a stirring blade, heated at 80 ° C. for 5 hours with mixing and stirring, then left at 20 ° C., and after 48 hours, the pH of the latex was adjusted to 7.0 using an aqueous sodium hydroxide solution. Then, the mixture was neutralized to 4, and the polymerization was completed to obtain a polyorganosiloxane latex. The polymerization rate of the obtained polyorganosiloxane was 87.5%, and the average particle size of the polyorganosiloxane was 0.17.
μm. Further, this latex was coagulated and dried with isopropanol to obtain a solid, which was extracted with toluene at 90 ° C. for 12 hours.

309 parts of the above polyorganosiloxane latex were placed in a separable flask equipped with a stirrer, 61 parts of distilled water was added, the atmosphere was replaced with nitrogen, the temperature was raised to 70 ° C., and then ferrous sulfate was added. A mixture of 0.002 parts, 0.006 parts of disodium ethylenediaminetetraacetate, 0.26 parts of Rongalit and 5 parts of distilled water was charged.
A mixed solution of 0.04 part of rt-butyl hydroperoxide and 10 parts of methyl methacrylate was added dropwise over 10 minutes, and then kept at 70 ° C. for 4 hours to complete the graft polymerization to the composite rubber. The polymerization rate of methyl methacrylate is
99.4%. The obtained graft copolymer latex was dropped into 200 parts of hot water containing 1.5% by weight of calcium chloride, coagulated, separated, washed, and dried at 75 ° C. for 16 hours to obtain a powdery graft copolymer S-. 96.9 parts were obtained.

(Examples 1 to 15, Comparative Examples 1 to 15) The graft copolymers S-1 to S-5 obtained in the above Reference Examples were added to the following amounts in the amounts shown in Table 1 and shown in Table 1. Physical properties were evaluated. In addition, vinyl chloride resin (hereinafter, PVC) is manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu high polymerization degree PVC "TK-2000".
(Degree of polymerization 2000), chlorinated polyethylene (hereinafter referred to as CP)
E) is "Eraslen 303B" manufactured by Showa Denko KK
(Chlorine content 32% by weight, heat of crystal fusion 12 cal /
g) was used. NBR rubber is manufactured by Nippon Synthetic Rubber Co., Ltd.
NC-38 was used.

PVC blending (Examples 1-5, Comparative Examples 1-5); PVC 100 parts Dioctyl phthalate 80 parts Calcium carbonate 10 parts Ba-Zn stabilizer 3 parts CPE blending (Examples 6-10, Comparative Examples 6-5) 10); CPE 100 parts Dioctyl phthalate 80 parts Calcium carbonate 10 parts Ba-Zn stabilizer 3 parts CPE / PVC blending (Examples 11 to 15, Comparative Examples 11 to 15); CPE 60 parts PVC 40 parts Dioctyl phthalate 80 parts Carbonate Calcium 10 parts Ba-Zn stabilizer 3 parts Processability was evaluated using a Kansai Roll Co., Ltd. 6 inch test roll machine at 150 ° C. and 15 rpm until the mixture was melted and wound. The time was measured.

After kneading for 5 minutes, the mixture was sandwiched between glass plates to obtain a sheet.

The surface appearance of the sheet was visually evaluated. ○
Indicates that the appearance is good, and X indicates that the appearance is poor.

In the weather resistance test, the surface appearance after 2,000 hours of sunshine weatherometer was visually evaluated.は indicates good appearance, and × indicates poor appearance.

In the compression set test, a test piece was prepared by using the sheet subjected to the weather resistance test and the sheet before the test,
Based on SK6301, the measurement was performed at 70 ° C. for 22 hours under a 25% compression condition.

The low-temperature rubber elasticity was evaluated by tentacles at -25 ° C. after storing the sheet in a low-temperature room at -20 ° C. for 5 hours or more. Elastic ones were evaluated as O, and embrittled ones as X.

Each of the blends was quickly wound around a roll, and the appearance of the obtained sheet was good.
Rubber elasticity and compression set before and after the weather resistance test were inferior.

The composite rubber-based graft copolymers S-1 to S-3 were quickly wound around a roll, and the appearance, compression set, and low-temperature rubber elasticity before and after the weather resistance test were all good.

When the acrylic graft copolymer S-4 was used, compression set and rubber elasticity at low temperature were inferior.

The silicone-based graft copolymer S-5, S
When -6 was used, the winding property, molded appearance, compression set, and rubber elasticity were inferior in any of the formulations.

[0071]

[Table 1]

[0072]

According to the present invention, the present inventors have found that a molded article obtained by processing has excellent weatherability, low compression set, and excellent workability without delaying melting during melt kneading. A composite rubber comprising a polyorganosiloxane component and a polyalkyl (meth) acrylate component having rubber elasticity
A composite rubber-based compression set reducing agent obtained by graft polymerization of at least one type of vinyl monomer and a soft resin composition containing the same have been developed.

The composite rubber-based compression set reducing agent has good heat resistance, flame retardancy, water repellency, release property, cushioning property, slidability, and impact strength. It is used in fields requiring properties, such as glass run channels, drainers, flush mount moldings, window frame materials for automobiles, soft parts of interior materials, building wall materials, flooring materials, and interior materials.

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Claims (2)

[Claims] 1. A compression set comprising a composite rubber-based graft copolymer obtained by graft-polymerizing one or more vinyl monomers onto a composite rubber comprising a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate component. Reducing agent (A). 2. A soft resin composition comprising the soft resin (B) and the compression permanent set reducing agent (A) according to claim 1 blended therein.