JP2007031700A - Composition for vulcanizing halogn-containing elastomer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for vulcanizing a halogen-containing elastomer, and a vulcanized rubber material obtained by vulcanizing the composition for vulcanization. <P>SOLUTION: This rubber composition for vulcanization contains a halogen-containing elastomer (A), a 4,4'-thiobisbenzenethiol derivative (B) represented by formula (I) wherein R<SP>1</SP>-R<SP>8</SP>are a hydrogen atom or a 1-4C alkyl group and they may be each the same or different, and calcium hydroxide and/or sodium carbonate (C). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a halogen-containing elastomer vulcanizing composition and a vulcanized rubber material thereof.

  In general, halogen-containing elastomers are widely used as materials having excellent physical properties such as heat resistance when vulcanized.

  However, since the carbon-halogen bond which is the vulcanization point in the polymer is somewhat chemically stable, it means a vulcanization system conventionally used (a combination of a vulcanizing agent and an acid acceptor). The same shall apply hereinafter), and it has been relatively difficult to vulcanize it easily and effectively.

On the other hand, ethylene thiourea has been used as an effective vulcanizing agent for vulcanizing halogen-containing elastomers (Non-patent Documents 1 and 2). In recent years, its use has been decreasing.
SLGraham et al., Bull.Environ.Contam.Toxicol., 7, 19 (1972) Shoji Teramoto, et al., Toxicology Research Bulletin, 3, 22 (1974)

  An object of the present invention is to provide a halogen-containing elastomer composition having a vulcanization system capable of easily, effectively and safely vulcanizing a halogen-containing elastomer in view of the above-mentioned problems of the prior art, and the composition An object of the present invention is to provide a vulcanized rubber material excellent in various physical properties such as heat resistance, obtained by vulcanizing styrene.

  As a result of various studies, the present inventors have found that the halogen-containing elastomer (A), the 4,4′-thiobisbenzenethiol derivative (B) represented by the following general formula (I), and calcium hydroxide and / or sodium carbonate The present invention has been completed by finding that the rubber composition for vulcanization characterized by containing (C) achieves the above-mentioned object.

[Ｒ¹〜Ｒ⁸ はそれぞれ同一でも異なっていてもよく、水素原子または炭素数1〜4のアルキル基を意味する。]

[R ^{1 to} R ⁸ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]

  According to the vulcanizing composition of the present invention, it is possible to vulcanize a halogen-containing elastomer easily, effectively and safely, and to provide a vulcanized rubber material excellent in various physical properties such as heat resistance. Further, the vulcanized rubber material of the present invention can be applied to various rubber members and rubber products that are required to have various physical properties such as electrophotographic equipment and automobile applications.

First, the halogen-containing elastomer (A) will be described.
The halogen-containing elastomer (A) constituting the main component of the composition of the present invention comprises a polymer mainly composed of a halogen-containing monomer, a polymer in which halogen is bonded to the polymer main chain, and a small amount of halogen as a crosslinking point. The polymer which contains is mentioned.
Examples of the polymer mainly composed of a halogen-containing monomer include epichlorohydrin rubber, polychloroprene, fluororubber, and the like. Polymers in which halogen is bonded to the polymer main chain include chlorinated polyethylene, polychlorinated polymer, and the like. Examples of the polymer containing a small amount of halogen as a crosslinking point include chlorinated butyl rubber, brominated butyl rubber, and acrylic rubber copolymerized with a chlorine-containing monomer.

  These polymers can be produced by polymerizing from various known monomers by a known means, but any of them may be a commercial product, and there is no particular limitation.

  Among the halogen-containing elastomers (A), as epichlorohydrin rubber, epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, epichlorohydrin-allyl glycidyl ether copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer , Epichlorohydrin-propylene oxide copolymer, epichlorohydrin-propylene oxide-allyl glycidyl ether terpolymer, and epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymer. Among these, epichlorohydrin homopolymer, epichlorohydrin-ethylene oxide copolymer, and epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer are preferable.

  In the case where the halogen-containing elastomer (A) is an epichlorohydrin rubber, the composition of the epichlorohydrin-ethylene oxide copolymer is such that the epichlorohydrin component is 5 mol% to 80 mol%, the ethylene oxide component is 20 mol% to 95 mol%, preferably epichlorohydrin. The component is 30 mol% to 60 mol%, the ethylene oxide component is 40 mol% to 70 mol%, and in the epichlorohydrin-allyl glycidyl ether copolymer, the epichlorohydrin component is 85 mol% to 99 mol%, and the allyl glycidyl ether component is 1 mol% to 15 mol%. Preferably, the epichlorohydrin component is 90 mol% to 98 mol%, the allyl glycidyl ether component is 2 mol% to 10 mol%, In the terpolymer of drin-ethylene oxide-allyl glycidyl ether, the epichlorohydrin component is 5 mol% to 75 mol%, the ethylene oxide component is 20 mol% to 90 mol%, the allyl glycidyl ether component is 1 mol% to 10 mol%, preferably the epichlorohydrin component is What uses 10 mol%-65 mol%, an ethylene oxide component is 30 mol%-85 mol%, and an allyl glycidyl ether component is 2 mol%-8 mol% is used.

  As a method for producing the polymer rubber, a known polymerization method can be employed. In particular, the method using the organotin-phosphate ester condensate described in US Pat. No. 3,773,694 of the present applicant as a polymerization catalyst is preferable because the polymer can be obtained in a high yield. That is, a product can be obtained with a polymerization yield of 90% or more by polymerizing at a polymerization temperature of 10 to 70 ° C. for 5 to 15 hours using an aliphatic or aromatic hydrocarbon as a solvent in the presence of the catalyst. The molecular weight range of these copolymer rubbers is preferably 30 to 200 in terms of Mooney viscosity at 100 ° C.

Next, the 4,4′-thiobisbenzenethiol derivative (B) will be described.
Examples of the 4,4′-thiobisbenzenethiol derivative (B) represented by the general formula (I) used in the present invention include 4,4′-thiobisbenzenethiol, 2-methyl-4,4 ′. -Thiobisbenzenethiol, 3-methyl-4,4'-thiobisbenzenethiol, 2,2'-dimethyl-4,4'-thiobisbenzenethiol, 3,3'-dimethyl-4,4'-thio Examples thereof include bisbenzenethiol.
Here, in the general formula (I), R ^{1 to} R ⁸ are defined as a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In interpreting the technical scope of the present invention, so-called equivalents (for example, , When an atom or functional group other than hydrogen is present in a part of the alkyl group).
4,4′-thiobisbenzenethiol is preferred.

  For example, 4,4'-thiobisbenzenethiol is a compound that has been useful as a raw material for producing high-performance engineering plastic materials and high-refractive plastic lenses that are excellent in heat resistance and chemical resistance. Synthesis methods are publicly known (Japanese Patent Laid-Open Nos. 3-014557, 4-257558, 4-264064, and 6-032773), and can be easily produced based on these methods. Moreover, you may use a commercial item.

  The blending ratio of the 4,4′-thiobisbenzenethiol derivative (B) may be 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight based on 100 parts by weight of the halogen-containing elastomer.

  In addition, a known vulcanizing agent for a halogen-containing elastomer may be used in combination with the 4,4′-thiobisbenzenethiol derivative (B) without departing from the spirit of the present invention. Examples of such vulcanizing agents for halogen-containing elastomers include polyamines (ethylenediamine, hexamethylenediamine, etc.), thioureas (ethylenethiourea, 1,3-diethylthiourea, etc.), and thiadiazoles (2,5-dimercapto-). 1,3,4-thiadiazole, etc.), mercaptotriazines (2,4,6-trimercapto-1,3,5-triazine, etc.), pyrazines (pyrazine-2,3-dithiocarbonate etc.), quinoxalines ( 6-methylquinoxaline-2,3-dithiocarbonate, etc.), organic peroxides (tert-butyl hydroperoxide, etc.), sulfur, morpholine polysulfides (morpholine disulfide, etc.), thioram polysulfides (tetramethylthiuram disulfide, etc.) Etc. These vulcanizing agents can be used alone or in combination of two or more.

Next, calcium hydroxide and / or sodium carbonate (C) will be described.
The calcium hydroxide and / or sodium carbonate (C) used in the present invention functions as a so-called acid acceptor used to absorb halogens generated when a halogen-containing elastomer is vulcanized.
As the acid acceptor (C), calcium hydroxide or sodium carbonate may be used alone, or calcium hydroxide and sodium carbonate may be used in combination.

  The compounding amount of the acid acceptor (C) may be 0.2 to 20 parts by weight, preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the halogen-containing elastomer.

  Moreover, you may use the well-known acid acceptor of a halogen containing elastomer in combination with the acid acceptor (C) which consists of calcium hydroxide and / or sodium carbonate in the range which does not deviate from the meaning of this invention. However, the known acid acceptor is preferably used when a known vulcanizing agent other than the 4,4'-thiobisbenzenethiol derivative (B) used in the present invention is used in combination.

  Known acid acceptors include Group II metal oxides, hydroxides, carbonates, carboxylates, silicates, borates, phosphites, and Group IV metal oxides of the Periodic Table. , Basic carbonate, basic carboxylate, basic phosphite, basic sulfite, tribasic lead sulfate, etc., and synthetic hydrotalcite represented by the following general formula (II) and general formula ( And the Li-Al clathrate compound represented by III).

[式中、xとyは0〜10の実数、ただしx+y=1〜10、zは1〜5の実数、wは0〜10の実数を表す。]

[Wherein x and y are real numbers of 0 to 0, where x + y = 1 to 10, z is a real number of 1 to 5, and w is a real number of 0 to 10. ]

[式中、Xは無機または有機のアニオンであり、nはアニオンXの価数であり、mは0〜3の実数を表す。]

[Wherein, X represents an inorganic or organic anion, n represents the valence of the anion X, and m represents a real number of 0 to 3. ]

  Specific examples of known acid acceptors include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, quicklime, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate , Calcium phosphite, zinc oxide, tin oxide, lisage, red lead, lead white, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite, base Mention may be made of basic lead sulfite and tribasic lead sulfate.

Also, known accelerators (vulcanization accelerators) and retarders can be added to the vulcanized rubber composition of the present invention.
Examples of vulcanization accelerators include basic silica, primary, secondary, tertiary amines (n-hexylamine, octylamine, etc.), organic acid salts of these amines and their adducts (n-butylamine acetate) ), Aldehyde ammonia accelerators (hexamethylenetetramine, reaction products of acetaldehyde and ammonia, etc.), aldehyde amine accelerators (condensates of aniline and butyraldehyde, etc.), guanidine accelerators (diphenylguanidine, etc.), thiazole System accelerators (2-mercaptobenzothiazole zinc salt, etc.), sulfenamide accelerators (N-ethyl-2-benzothiazylsulfenamide, etc.), thiuram accelerators (tetramethylthiuram disulfide, etc.), dithiocarbamine Acid accelerators (such as zinc dimethyldithiocarbamate), 1,8-diazabicyclo (5,4,0) Undecene-7 and its weak acid salt, 1,5-diazabicyclo (4,3,0) nonene-5, 6-dibutylamino 1,8-diazabicyclo (5,4,0) undecene-7 and its weak acid salt, A class ammonium compound etc. can be mentioned.
Examples of the retarder include acidic silica, N-cyclohexylthiophthalimide, di- (O-benzamidophenyl) disulfide, and phthalic anhydride.
These vulcanization accelerators and retarders may be used alone or in combination of two or more. The amount of the vulcanization accelerator or retarder is 0 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the halogen-containing elastomer.

  The rubber composition for vulcanization of the present invention includes other additives usually used in the technical field, such as lubricants, anti-aging agents, fillers, reinforcing agents, plasticizers, processing aids, pigments, foaming agents. Etc. can be arbitrarily blended.

  Furthermore, blending with rubber, resin, or the like that is commonly performed in the technical field is also possible without departing from the spirit of the present invention. Examples of the rubber used in the present invention include butadiene rubber, styrene-butadiene rubber, isoprene rubber, natural rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-isoprene rubber, ethylene-propylene-diene rubber, and the like. For example, PMMA (polymethyl methacrylate) resin, PS (polystyrene) resin, PUR (polyurethane) resin, PVC (polyvinyl chloride) resin, EVA (ethylene / vinyl acetate) resin, AS (styrene / acrylonitrile) resin, Examples include PE (polyethylene) resin.

[式中、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹およびＲ¹²はそれぞれ同一または異なって、炭素原子数１〜１８のアルキル基、アルケニル基、アリール基、シクロアルキル基、アルコキシ基、または主鎖がポリオキシエチレン鎖もしくはポリオキシプロピレン鎖で末端にアルキル基、アルケニル基、アリール基、シクロアルキル基、アルコキシ基もしくは水酸基を有する基である。]
で表され、アニオン種が過塩素酸イオンのような無機酸イオン、または、塩化物イオンのようなハロゲンイオンなどを有した第四級アンモニウム塩などを任意に添加してよい。 By the way, when imparting conductivity to the rubber composition for vulcanization of the present invention, as a conductivity imparting agent, electron conductive particles such as carbon black, metal salts such as alkali metal salts and alkaline earth metal salts, or cations Species is general formula (IV)

[In the formula, R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are the same or different, and the alkyl group, alkenyl group, aryl group, cycloalkyl group, alkoxy group, or main chain of 1 to 18 carbon atoms is A group having an oxyethylene chain or a polyoxypropylene chain and having an alkyl group, alkenyl group, aryl group, cycloalkyl group, alkoxy group or hydroxyl group at the terminal. ]
A quaternary ammonium salt in which the anion species has an inorganic acid ion such as a perchlorate ion or a halogen ion such as a chloride ion may be optionally added.

In these salts serving as a conductivity-imparting agent, examples of the cation species include Li, Na, K, Mg, Ca, cations of transition metals such as Fe, Cu, Zn, and Ag metals, tetramethylammonium, and tetrabutylammonium. And phosphonium ions such as triethylmethylphosphonium and tetraethylphosphonium. Examples of the anion species include chlorine ions, perchlorate ions, thiocyanate ions, tetrafluoroborate ions, nitrate ions, AsF ⁶⁻ , PF ⁶⁻ , dodecylbenzenesulfonate ions, etc. A compound selected from these combinations can be used as the conductivity-imparting agent.

  The amount of the conductivity-imparting agent may be 0 to 10 parts by weight, for example, 0 to 5 parts by weight with respect to 100 parts by weight of the halogen-containing elastomer.

  As a method for blending the composition of the present invention, any means conventionally used in the field of polymer processing, for example, a mixing roll, a Banbury mixer, various kneaders, and the like can be used.

  As the blending procedure, it can be carried out by a usual procedure performed in the field of polymer processing. For example, first knead only the polymer, then create a kneading compound containing the vulcanizing agent and a compounding agent other than the vulcanization accelerator, and then add the vulcanizing agent and vulcanization accelerator to the kneading B It can be done in the procedure to do.

  The composition of the present invention can be made into a vulcanized product, that is, a vulcanized rubber material, usually by heating to 100 to 250 ° C. The vulcanization time varies depending on the temperature, but it is usually between 0.5 and 300 minutes. Vulcanization molding is not only when the vulcanization and molding are performed integrally, or when the vulcanized composition is formed by heating again to the vulcanized composition previously molded, or the vulcanized product is heated first. Any of the cases where the vulcanized rubber material is processed for molding may be used. As a specific method of vulcanization molding, any method such as compression molding using a mold, injection molding, a steam can, an air bath, infrared rays, or heating using a microwave can be used.

  The semiconductive rubber member used in the electrophotographic process in the present invention means a semiconductive rubber roll for charging, developing, transferring, etc., a semiconductive endless belt, etc. used for a copying machine, a printer or the like.

  In addition, the extruded vulcanized product and the mold vulcanized product used for automobile use in the present invention are a fuel oil hose around a fuel tank such as a fuel hose, a filler neck hose, a vent hose, a vapor hose, an emission control hose, a PCV. It means air hoses such as hoses.

The present invention will be specifically described with reference to examples and comparative examples. However, the present invention is not limited to these.
[Examples 1-6, Comparative Examples 1-6]
Each material shown in Table 1-1 and Table 2-1 was kneaded with a kneader and an open roll to prepare an unvulcanized rubber sheet.
(1) The Mooney scorch test defined in JIS K6300 was performed using the obtained unvulcanized rubber sheet.
(2) The vulcanization curve of the unvulcanized rubber sheet obtained in the same manner was measured at 170 ° C. for 15 minutes using a JSR Clastometer Type III.
(3) The obtained unvulcanized rubber sheet was press vulcanized at 170 ° C. for 15 minutes to obtain a primary vulcanizate having a thickness of 2 mm. Using the obtained vulcanizate, the tensile test (normal physical properties) was evaluated. Each evaluation test was performed in accordance with the method described in JIS K 6251 in order.
(4) Using the primary vulcanizate, a heat aging test was conducted according to the air heating aging test (normal oven method) described in JIS K 6257.
(5) The obtained unvulcanized rubber sheet was press vulcanized at 170 ° C. for 20 minutes using a test piece preparation mold, and a cylindrical test piece primary vulcanized having a diameter of about 29 mm and a height of about 12.5 mm. I got a thing. Using the obtained vulcanizate, a compression set test was conducted according to the method described in JIS K 6262.

The test results of Examples and Comparative Examples obtained from each test method are shown in Table 1-2 and Table 2-2.
In each table, the lowest viscosity Vm, _{t 5} Mooney scorch time specified in Mooney scorch test JIS _{K6300, M 100} tensile stress at 100% elongation specified in the tensile test of JIS K6251, Tb is the tensile test JIS K6251 The tensile strength defined, Eb, is the elongation defined in the tensile test of JIS K6251, and Hs is the hardness defined in the hardness test of JIS K6253.
Moreover, about Examples 1-6 and Comparative Examples 1-5, the vulcanization curve of an unvulcanized rubber sheet is shown in FIG.

  By comparing each Example with Comparative Examples 1 to 5, calcium hydroxide and / or sodium carbonate (C) with respect to the 4,4′-thiobisbenzenethiol derivative (B) represented by the general formula (I) It can be seen that the halogen-containing elastomer can be easily and effectively vulcanized by using as an acid acceptor, and the vulcanized product exhibits various physical properties such as excellent heat aging resistance. It can also be seen that the compression set is superior to that of Comparative Example 6 in which ethylenethiourea is used in place of the component (B) 4,4'-thiobisbenzenethiol.

  The vulcanized rubber material of the present invention is used as a material for rubber products and resin products utilizing the excellent heat resistance, oil resistance, weather resistance, ozone resistance, and wear resistance of halogen-containing elastomers, or as a raw material for adhesives and coating materials. Can be used widely. In particular, epichlorohydrin rubber materials are extremely effective for automobile applications such as fuel hoses, air hoses and tube materials, and OA equipment applications such as semiconductive rollers, belts and drums.

3 is a graph showing a vulcanization curve of an unvulcanized rubber sheet.

Claims (5)

(A) a halogen-containing elastomer, (B) a 4,4′-thiobisbenzenethiol derivative represented by the following formula (I), and (C) calcium hydroxide and / or sodium carbonate Rubber composition for sulfur.

[R ^{1 to} R ⁸ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ]   (A) Halogen-containing elastomer is epichlorohydrin rubber, chlorinated polyethylene, polyvinyl chloride, polychloroprene, chlorosulfonated polyethylene, chlorinated butyl rubber, brominated butyl rubber, fluoro rubber, and acrylic rubber copolymerized with chlorine-containing monomers The rubber composition for vulcanization according to claim 1, wherein the rubber composition is at least one polymer selected from the group consisting of:   A vulcanized rubber material obtained by vulcanizing the rubber composition for vulcanization according to claim 1 or 2.   A semiconductive rubber member used in an electrophotographic process, which is obtained by molding and vulcanizing the vulcanizing rubber composition according to claim 1. An extrusion vulcanized product or a mold vulcanized product for use in automobiles, obtained by molding and vulcanizing the rubber composition for vulcanization according to claim 1 or 2.

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