JP2011184611A - Use of s-(4-aminobutyl)thiosulfuric acid or metal salt thereof for improving viscoelastic properties of vulcanized rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve viscoelastic properties of a vulcanized rubber used for production of a tire. <P>SOLUTION: S-(4-aminobutyl)thiosulfuric acid or its metal salt is used for improving viscoelastic properties of the vulcanized rubber. A metal ion in the S-(4-aminobutyl)thiosulfuric acid metal salt is preferably a lithium ion, a sodium ion, a potassium ion, a cesium ion, a cobalt ion, a copper ion, or a zinc ion. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to the use of S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof for improving the viscoelastic properties of vulcanized rubber.

  In recent years, there has been a demand for improvement in fuel consumption (that is, reduction in fuel consumption) of automobiles due to a demand for environmental protection. In the field of automobile tires, it is known that the fuel efficiency of automobiles is improved by improving viscoelastic characteristics (see Non-Patent Document 1).

Edited by Japan Rubber Association “Introduction to Rubber Technology” Maruzen Co., Ltd., p. 124

  In the field of tires, a method for improving the viscoelastic properties of vulcanized rubber used for tire manufacture has been demanded.

  As a result of intensive studies under such circumstances, the present inventor has reached the present invention.

That is, the present invention
1. 1. S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof for improving viscoelastic properties of vulcanized rubber; The use according to item 1 above, wherein the metal ion in the metal salt of S- (4-aminobutyl) thiosulfuric acid is lithium ion, sodium ion, potassium ion, cesium ion, cobalt ion, copper ion or zinc ion;
Etc. are provided.

  The present invention can provide a method for improving the viscoelastic properties of a vulcanized rubber used for manufacturing a tire.

Hereinafter, the present invention will be described in detail.
In the present invention, “improving viscoelastic properties” can include, for example, modifying a loss factor (tan δ) of a vulcanized rubber as described below.

The metal salt of S- (4-aminobutyl) thiosulfuric acid used in the present invention has the following formula (H ₂ N— (CH ₂ ) ₄ —SSO ₃ ⁻ ) _n · M ^{n +}
(In the formula, M ^{n +} represents a metal ion, and n represents its valence.)
It is a compound shown by these.

  The metal salt of S- (4-aminobutyl) thiosulfuric acid is, for example, a method of reacting 4-halobutylamine with sodium thiosulfate; reacting phthalimide potassium salt with 1,4-dihalobutane, It can be produced by any known method such as a method of reacting with sodium thiosulfate and then hydrolyzing the obtained compound. The metal salt of S- (4-aminobutyl) thiosulfuric acid thus produced usually contains about 0.1% to 5% of water.

S- (4-aminobutyl) thiosulfuric acid is, for example, a method in which hydrochloric acid is allowed to act on the metal salt of S- (4-aminobutyl) thiosulfuric acid obtained by the above-mentioned production method to remove the metal as a chloride; It can be produced by any known method. The S- (4-aminobutyl) thiosulfuric acid thus produced usually contains about 0.1% to 5% water.

As the metal ion represented by M ^{n +} , lithium ion, sodium ion, potassium ion, cesium ion, cobalt ion, copper ion and zinc ion are preferable, and lithium ion, sodium ion and potassium ion are more preferable. n represents the valence of the metal ion, and is not particularly limited as long as it is a possible range for the metal. For example, in the case of an alkali metal ion such as lithium ion, sodium ion, potassium ion or cesium ion, n is usually 1, n is usually 2 or 3 in the case of cobalt ion, and n is in the case of copper ion. Usually, it is an integer of 1 to 3, and in the case of zinc ion, n is usually 2. According to said manufacturing method, although a sodium salt is obtained normally, what is necessary is just to exchange cation as needed.

  The median diameter of S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof is preferably in the range of 0.05 to 100 μm. Such median diameter can be measured by a laser diffraction method.

  This invention is implemented by mix | blending this S- (4-aminobutyl) thiosulfuric acid or its metal salt at the time of manufacture of vulcanized rubber.

  The vulcanized rubber usually contains a rubber component, a filler, zinc oxide, a sulfur component and a vulcanization accelerator.

  Rubber components include natural rubber, epoxidized natural rubber, deproteinized natural rubber and other modified natural rubber, as well as polyisoprene rubber (IR), styrene / butadiene copolymer rubber (SBR), polybutadiene rubber (BR), and acrylonitrile. -Various synthetic rubbers such as butadiene copolymer rubber (NBR), isoprene / isobutylene copolymer rubber (IIR), ethylene / propylene-diene copolymer rubber (EPDM), halogenated butyl rubber (HR), etc. are exemplified. Highly unsaturated rubbers such as rubber, styrene / butadiene copolymer rubber and polybutadiene rubber are preferably used. Particularly preferred is natural rubber. It is also effective to combine several rubber components such as a combination of natural rubber and styrene / butadiene copolymer rubber, a combination of natural rubber and polybutadiene rubber.

  Examples of natural rubber include natural rubber of grades such as RSS # 1, RSS # 3, TSR20, SIR20 and the like. As the epoxidized natural rubber, those having a degree of epoxidation of 10 to 60 mol% are preferable, and examples thereof include ENR25 and ENR50 manufactured by Kumpoulan Guthrie. As the deproteinized natural rubber, a deproteinized natural rubber having a total nitrogen content of 0.3% by weight or less is preferable. The modified natural rubber contains a polar group obtained by reacting natural rubber with 4-vinylpyridine, N, N, -dialkylaminoethyl acrylate (for example, N, N, -diethylaminoethyl acrylate), 2-hydroxyacrylate, or the like in advance. Natural rubber is preferably used.

  Examples of the SBR include emulsion polymerization SBR and solution polymerization SBR described in pages 210 to 211 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. In particular, solution-polymerized SBR is preferably used as a rubber composition for a tread, and further, the molecular terminal is terminated by using 4,4′-bis- (dialkylamino) benzophenone such as “Nippol (registered trademark) NS116” manufactured by Nippon Zeon Co., Ltd. Modified polymerized SBR, solution polymerized SBR modified with molecular halides using tin halide compounds such as “SL574” manufactured by JSR, commercially available silane-modified solution polymerized SBR such as “E10” and “E15” manufactured by Asahi Kasei , Lactam compounds, amide compounds, urea compounds, N, N-dialkylacrylamide compounds, isocyanate compounds, imide compounds, silane compounds having an alkoxy group (trialkoxysilane compounds, etc.), and aminosilane compounds alone, Or a silane compound having a tin compound and an alkoxy group, Using two or more different compounds as described above, such as an alkylacrylamide compound and a silane compound having an alkoxy group, each of the molecular ends obtained by modifying the molecular ends is either nitrogen, tin, or silicon, or those Solution polymerization SBR having a plurality of elements is particularly preferably used. Oil-extended SBR in which oil such as post-polymerization process oil and aroma oil is added to emulsion polymerization SBR and solution polymerization SBR can be preferably used as a rubber composition for treads.

  Examples of BR include solution polymerization BR such as high cis BR having 90% or more of cis 1,4 bond and low cis BR having cis bond of around 35%, and low cis BR having a high vinyl content is preferably used. . Furthermore, tin-modified BR such as “Nipol (registered trademark) BR 1250H” manufactured by Nippon Zeon, 4,4′-bis- (dialkylamino) benzophenone, tin halide compound, lactam compound, amide compound, urea compound, N, An N-dialkylacrylamide compound, an isocyanate compound, an imide compound, a silane compound having an alkoxy group (trialkoxysilane compound, etc.), an aminosilane compound alone, or a silane compound having a tin compound and an alkoxy group, Using two or more different compounds as described above, such as an alkylacrylamide compound and a silane compound having an alkoxy group, each of the molecular ends obtained by modifying the molecular ends is either nitrogen, tin, or silicon, or those Solution polymerization B with multiple elements But particularly preferably used. These BRs can be preferably used as a rubber composition for a tread or a rubber composition for a sidewall, and are usually used in a blend with SBR and / or natural rubber. In the rubber composition for treads, the blend ratio is preferably 60 to 100% by weight for SBR and / or natural rubber and 0 to 40% by weight for BR relative to the total rubber weight. In the rubber composition for sidewalls, The SBR and / or natural rubber is preferably 10 to 70% by weight and the BR is preferably 90 to 30% by weight based on the total rubber weight, and further the natural rubber is 40 to 60% by weight and BR 60 to 40% based on the total rubber weight. Weight percent blends are particularly preferred. In this case, a blend of modified SBR and non-modified SBR or a blend of modified BR and non-modified BR is also preferable.

Examples of the filler include carbon black, silica, talc, clay, aluminum hydroxide, titanium oxide and the like that are usually used in the rubber field. Carbon black and silica are preferably used, and carbon black is particularly preferable. Preferably used. Examples of the carbon black include those described on page 494 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. HAF (High Abrasion Furnace), SAF (Super Abrasion Furnace), ISAF (Intermediate). Carbon blacks such as SAF), FEF (Fast Extrusion Furnace), MAF, GPF (General Purpose Furnace), and SRF (Semi-Reinforcing Furnace) are preferred. The rubber composition for a tire tread CTAB surface 40~250m ² / g, nitrogen adsorption specific surface area 20 to 200 m ² / g, carbon black having a particle diameter 10~50nm is preferably used, with CTAB surface 70~180m ² / g A certain carbon black is more preferable, and examples thereof include N110, N220, N234, N299, N326, N330, N330T, N339, N343, N351 and the like in the ASTM standard. A surface-treated carbon black in which 0.1 to 50% by weight of silica is attached to the surface of the carbon black is also preferable. Furthermore, it is also effective to combine several kinds of fillers such as the combined use of carbon black and silica. In the rubber composition for a tire tread, it is preferable to use carbon black alone or both carbon black and silica. In the rubber composition for carcass and sidewall, carbon black having a CTAB surface area of 20 to 60 m ² / g and a particle diameter of 40 to 100 nm is preferably used. Examples thereof include N330, N339, N343, N351, N550 in the ASTM standard. N568, N582, N630, N642, N660, N662, N754, N762, and the like. The amount of the filler used is not particularly limited, but is preferably in the range of 5 to 100 parts by weight per 100 parts by weight of the rubber component. Particularly preferably, the amount is 30 to 80 parts by weight when only carbon black is used as a filler, and 5 to 50 parts by weight when used in combination with silica in a tread member application.

Examples of the silica include silica having a CTAB specific surface area of 50 to 180 m ² / g and a nitrogen adsorption specific surface area of 50 to 300 m ² / g. “AQ”, “AQ-N” manufactured by Tosoh Silica Co., Ltd., Degussa "Ultrasil (registered trademark) VN3", "Ultrasil (registered trademark) 360", "Ultrasil (registered trademark) 7000", Rhodia "Zeosil (registered trademark) 115GR", "Zeosil (registered trademark)" Commercially available products such as “1115MP”, “Zeosil (registered trademark) 1205MP”, “Zeosil (registered trademark) Z85MP”, “Nippal (registered trademark) AQ” manufactured by Nippon Silica Co., Ltd. are preferably used. Further, silica having a pH of 6 to 8, silica containing 0.2 to 1.5% by weight of sodium, true spherical silica having a roundness of 1 to 1.3, silicone oil such as dimethyl silicone oil, and ethoxysilyl group It is also preferable to use an organosilicon compound containing silane, silica surface-treated with an alcohol such as ethanol or polyethylene glycol, and silica having two or more different nitrogen adsorption specific surface areas.

  The amount of the filler used is not particularly limited, but silica is preferably used in the rubber composition for a tread for passenger cars, and the range of 10 to 120 parts by weight per 100 parts by weight of the rubber component is preferable. Moreover, when mix | blending a silica, it is preferable to mix | blend 5-50 weight part of carbon black, and the blend ratio of silica / carbon black is especially preferable 0.7 / 1-1 / 0.1. When silica is usually used as a filler, bis (3-triethoxysilylpropyl) tetrasulfide ("Si-69" manufactured by Degussa) or bis (3-triethoxysilylpropyl) disulfide ("Si-" manufactured by Degussa) 75 "), bis (3-diethoxymethylsilylpropyl) tetrasulfide, bis (3-diethoxymethylsilylpropyl) disulfide, octanethioic acid S- [3- (triethoxysilyl) propyl] ester (General Electronic Silicones) "NXT silane"), octanethioic acid S- [3-{(2-methyl-1,3-propanedialkoxy) ethoxysilyl} propyl] ester and octanethioic acid S- [3-{(2-methyl-1, 3-propanedialkoxy) methylsilyl} propyl] ester Rutriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-octyltrimethoxysilane , N-octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, 3-methacryloxypropyltrimethoxysilane, 3 -Methacryloxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) ) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, (3-glycidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) triethoxy Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyl It is preferable to add a compound having a functional group such as an element such as silicon or alkoxysilane that can be bonded to silica, such as one or more silane coupling agents selected from the group consisting of triethoxysilane, and bis (3 -Triethoxysilylpropyl) tetrasulfide (Degussa "Si-69 ), Bis (3-triethoxysilylpropyl) disulfide (manufactured by Degussa, "Si-75"), 3-octanoylthiopropyl aminopropyltriethoxysilane (General Electronic Silicon Inc. Ltd. "NXT silane") is particularly preferred. Although the addition time of these compounds is not particularly limited, it is preferably compounded into rubber at the same time as silica, and the compounding amount is preferably 2 to 10% by weight, more preferably 7 to 9% by weight, based on silica. is there. In the case of blending, the blending temperature is preferably 80 to 200 ° C, more preferably 110 to 180 ° C. Furthermore, when silica is used as the filler, in addition to silica, an element such as silicon that can be bonded to silica or a compound having a functional group such as alkoxysilane, monohydric alcohol such as ethanol, butanol, octanol, or ethylene Glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol, polyether polyol and other dihydric alcohols, N-alkylamines, amino acids, liquid polybutadienes whose molecular ends are carboxyl-modified or amine-modified, etc. It is also preferable to mix.

Examples of the aluminum hydroxide include aluminum hydroxide having a nitrogen adsorption specific surface area of 5 to 250 m ² / g and a DOP oil supply amount of 50 to 100 ml / 100 g.

  Examples of the sulfur component include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur. Usually, powdered sulfur is preferred, and insoluble sulfur is preferred when used for tire members having a large amount of sulfur such as belt members.

  Moreover, it is preferable to mix | blend and knead | mix zinc oxide and a vulcanization accelerator other than said S- (4-aminobutyl) thiosulfuric acid metal salt, a rubber component, a filler, and a sulfur component.

  Examples of vulcanization accelerators include thiazole-based vulcanization accelerators and sulfur compounds described on pages 412 to 413 of Rubber Industry Handbook <Fourth Edition> (issued by the Japan Rubber Association on January 20, 1994). Examples thereof include phenamide vulcanization accelerators and guanidine vulcanization accelerators.

  Specifically, for example, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N-dicyclohexyl-2 -Benzothiazolylsulfenamide (DCBS), 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), diphenylguanidine (DPG). When carbon black is used as the filler, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N-dicyclo Hexyl-2-benzothiazolylsulfenamide (DCBS) or dibenzothiazyl disulfide (MBTS) and diphenylguanidine (DPG) are preferably used in combination, and when silica and carbon black are used in combination as fillers N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N-dicyclohexyl-2-benzothiazolylsulfate Fenamide (DCBS), dibenzothiazyl disulfide It is preferable that either of MBTS) in combination with diphenyl guanidine (DPG).

  The ratio of sulfur to the vulcanization accelerator is not particularly limited, but is preferably in the range of sulfur / vulcanization accelerator = 2/1 to 1/2 by weight ratio. Further, EV vulcanization in which the ratio of sulfur / vulcanization accelerator, which is a method for improving heat resistance in rubber members mainly composed of natural rubber, is 1 or less is used in the present invention in applications that particularly require improvement in heat resistance. Preferably used.

  Generally, when producing a vulcanized rubber, the production is basically performed in three steps. That is, the first step of blending rubber components, fillers, zinc oxide, etc. at a relatively high temperature, the second step of blending sulfur components, vulcanization accelerators, etc. at a relatively low temperature, and finally adding at a relatively high temperature. A vulcanized rubber is obtained by the third step of vulcanization.

  The metal salt of S- (4-aminobutyl) thiosulfuric acid may be blended in the second step, but is preferably blended in the first step together with the filler and zinc oxide. The amount of S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof used is preferably in the range of 0.1 to 10 parts by weight per 100 parts by weight of the rubber component. More preferably, it is the range of 0.3-3 weight part. The blending temperature in the case of blending in the first step is preferably 80 to 200 ° C, more preferably 110 to 180 ° C. The blending temperature when blended in the second step is preferably 50 to 100 ° C.

  S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof can be blended with a supporting agent in advance. Examples of such a carrier include the fillers exemplified above and “inorganic fillers and reinforcing agents” described on pages 510 to 513 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. Carbon black, silica, calcined clay and aluminum hydroxide are preferred. The amount of the carrier used is not particularly limited, but is preferably in the range of 10 to 1000 parts by weight per 100 parts by weight of S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof.

  It is also possible to mix and knead an agent for improving the viscoelastic properties conventionally used in the rubber field. Examples of such an agent include N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“SUMIFINE (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), JP-A-63. Dithiouracil compounds described in JP-A No. 233942, nitrosoquinoline compounds such as 5-nitroso-8-hydroxyquinoline (NQ-58) described in JP-A-60-82406, “Tactrol (registered trademark) AP, manufactured by Taoka Chemical Co., Ltd.” V-200 ”, alkylphenol / sulfur chloride condensates described in JP-A No. 2009-138148 such as“ BALTAC 2, 3, 4, 5, 7, 710 ”manufactured by Penwald, and bis (3-triethoxysilyl) Propyl) tetrasulfide (“Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (Degussa) “Si-75”), bis (3-diethoxymethylsilylpropyl) tetrasulfide, bis (3-diethoxymethylsilylpropyl) disulfide, octanethioic acid S- [3- (triethoxysilyl) propyl] ester, octanethio Acid S- [3-{(2-methyl-1,3-propanedialkoxy) ethoxysilyl} propyl] ester and octanethioic acid S- [3-{(2-methyl-1,3-propanedialkoxy) methylsilyl} Propyl] ester phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, n- Oh Tiltrimethoxysilane, n-octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, 3-methacryloxypropyltri Methoxysilane, 3-methacryloxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2- Aminoethyl) -3-aminopropyltriethoxysilane, (3-glycidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) triethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Silane coupling agents such as rutrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 1,6-bis (N, N′-dibenzylthiocarbamoyldithio) hexane (“BA9188” manufactured by Bayer), 1,6-hexamethylenedithiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (Flexis) “Perkalink 900”), 1-benzoyl-2-phenylhydrazide, 1- or 3-hydroxy-N ′-(1-methylethylidene) -2-naphthoic acid hydrazide, 1 described in JP-A-2004-91505 -Or 3-hydroxy-N '-(1-methylpropylidene)- -Naphthoic acid hydrazide, 1- or 3-hydroxy-N '-(1,3-dimethylbutylidene) -2-naphthoic acid hydrazide and 1- or 3-hydroxy-N'-(2-furylmethylene) -2- Carboxylic acid hydrazide derivatives such as naphthoic acid hydrazide, 3-hydroxy-N ′-(1,3-dimethylbutylidene) -2-naphthoic acid hydrazide, 3-hydroxy-N ′-( 1,3-diphenylethylidene) -2-naphthoic acid hydrazide and 3-hydroxy-N ′-(1-methylethylidene) -2-naphthoic acid hydrazide, bismercaptooxadiazole compounds described in JP-A-2006-328310, Japanese Patent Application Laid-Open No. 2009-40898, pyrithione salt compound, Japanese Patent Application Laid-Open No. 2006-249361 Cobalt hydroxide compounds described are exemplified.

  Among them, N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“Sumifine (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), 5-nitroso-8-hydroxyquinoline ( NQ-58), bis (3-triethoxysilylpropyl) tetrasulfide (“Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (“Si-75” manufactured by Degussa), 1, 6-bis (N, N′-dibenzylthiocarbamoyldithio) -hexane (“KA9188” manufactured by Bayer), hexamethylenebisthiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (flexis Alkyl polymers such as “Takaroll (registered trademark) AP, V-200” manufactured by Taoka Chemical Co., Ltd. Nord-sulfur chloride condensate is preferable.

  When blending zinc oxide, blending in the first step is preferable, and when blending the vulcanization accelerator, blending in the second step is preferable.

  Various compounding agents conventionally used in the rubber field can be blended and kneaded. Examples of such compounding agents include anti-aging agents; oils; fatty acids such as stearic acid; Coumarone resin NG4 (softening point 81 to 100 ° C.) of Nittsu Chemical Co., Ltd., process resin of Kobe Oil Chemical Co., Ltd. Coumarone-indene resin such as AC5 (softening point 75 ° C.); Terpene resin such as terpene resin, terpene / phenol resin, aromatic modified terpene resin; Mitsubishi Gas Chemical Co., Ltd. “Nikanol (registered trademark) A70” (softening point) Rosin derivatives such as 70 to 90 ° C .; hydrogenated rosin derivatives; novolac alkylphenol resins; resole alkylphenol resins; C5 petroleum resins; liquid polybutadienes. These compounding agents can be blended in either the first step or the second step.

  Examples of the oil include process oil and vegetable oil. Examples of the process oil include paraffinic process oil, naphthenic process oil, and aromatic process oil.

  Examples of the anti-aging agent include those described in pages 436 to 443 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. Among them, N-phenyl-N′-1,3-dimethylbutyl-p-phenylenediamine (6PPD), reaction product of aniline and acetone (TMDQ), poly (2,2,4-trimethyl-1,2-) dihydro Quinoline) (“Antioxidant FR” manufactured by Matsubara Sangyo Co., Ltd.), synthetic wax (paraffin wax, etc.) and vegetable wax are preferably used.

  It is also possible to blend and knead a vulcanizing agent such as morpholine disulfide conventionally used in the rubber field. These are preferably blended in the second step.

  Further, a peptizer and a retarder may be blended and kneaded, and various general rubber chemicals and softeners may be blended and kneaded as necessary.

  Examples of the retarder include phthalic anhydride, benzoic acid, salicylic acid, N-nitrosodiphenylamine, N- (cyclohexylthio) -phthalimide (CTP), sulfonamide derivatives, diphenylurea, bis (tridecyl) pentaerythritol-diphosphite, etc. N- (cyclohexylthio) -phthalimide (CTP) is preferably used.

  The retarder may be blended and kneaded in the first step, but is preferably blended and kneaded in the second step.

  The amount of the retarder used is not particularly limited, but is preferably in the range of 0.01 to 1 part by weight per 100 parts by weight of the rubber component. Particularly preferred is 0.05 to 0.5 parts by weight.

  The temperature condition in the first step is preferably 200 ° C. or lower. More preferably, it is 120-180 degreeC. The temperature condition in the second step is preferably 60 to 120 ° C.

  Next, the 3rd process of heat-processing the kneaded material obtained at the 2nd process is demonstrated.

  The temperature condition in the heat treatment is preferably 120 to 180 ° C. The heat treatment is usually performed at normal pressure or under pressure.

  The use of the present invention usually includes a step of processing the kneaded product in a specific state before subjecting the kneaded product obtained in the second step to the heat treatment in the third step.

  Here, the “process for processing the kneaded product into a specific state” means, for example, in the tire field, the “process for coating the kneaded product on a steel cord”, “step for coating a carcass fiber cord”, “tread” The process of processing into the shape of the member for use "etc. are mentioned. In addition, each member such as a belt, a carcass, an inner liner, a sidewall, and a tread (cap tread or under tread) respectively obtained by these steps is usually combined with other members by a method usually performed in the field of tires. Further, after being molded into the shape of a tire, that is, through the step of incorporating the kneaded product into the tire, it is subjected to the heat treatment in the third step in the state of the raw tire containing the kneaded product. Such heat treatment is usually performed under pressure.

  Of the rubber blends suitable for tread members suitable for trucks, buses, light trucks, and large construction tires, the rubber component is preferably natural rubber alone or a blend of SBR and / or BR containing natural rubber as a main component. As the filler, carbon black alone or a blend with carbon black containing silica as a main component is preferably used. Further, N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“Sumifine (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), 5-nitroso-8-hydroxyquinoline ( NQ-58), bis (3-triethoxysilylpropyl) tetrasulfide (Si-69), bis (3-triethoxysilylpropyl) disulfide (Si-75), 1,6-bis (N, N′-di) Benzylthiocarbamoyldithio) -hexane (“KA9188” manufactured by Bayer), hexamethylene bisthiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (“Parkalink 900” manufactured by Flexis), Taoka Viscosity of alkylphenol / sulfur chloride condensates such as chemical “Tacchirol (registered trademark) AP, V-200” It is preferable to use a sex modifier.

  Among rubber blends suitable for tread members suitable for passenger car tires, the rubber component includes, as a main component, solution-polymerized SBR having a molecular end modified with a silicon compound alone or the above-mentioned terminal-modified solution-polymerized SBR, and non-modified solution polymerization. A blend with at least one rubber selected from the group consisting of SBR, emulsion polymerization SBR, natural rubber and BR is preferred. Moreover, as a filler, the blend with carbon black which has a silica as a main component is used preferably. Further, N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“Sumifine (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), 5-nitroso-8-hydroxyquinoline ( NQ-58), bis (3-triethoxysilylpropyl) tetrasulfide (Si-69), bis (3-triethoxysilylpropyl) disulfide (Si-75), 1,6-bis (N, N′-di) Benzylthiocarbamoyldithio) -hexane (“KA9188” manufactured by Bayer), hexamethylene bisthiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (“Parkalink 900” manufactured by Flexis), Taoka Viscoelasticity of alkylphenol / sulfur chloride condensates such as “Tacchirol (registered trademark) AP, V-200” It is preferable to use a modifier.

  Among the rubber blends suitable for the sidewall member, the rubber component includes a blend of at least one rubber selected from the group consisting of BR as a main component, non-modified solution polymerization SBR, emulsion polymerization SBR, and natural rubber. preferable. Further, as the filler, carbon black alone or a blend with silica containing carbon black as a main component is preferably used. Further, N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“Sumifine (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), 5-nitroso-8-hydroxyquinoline ( NQ-58), bis (3-triethoxysilylpropyl) tetrasulfide (Si-69), bis (3-triethoxysilylpropyl) disulfide (Si-75), 1,6-bis (N, N′-di) Benzylthiocarbamoyldithio) -hexane (“KA9188” manufactured by Bayer), hexamethylene bisthiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (“Parkalink 900” manufactured by Flexis), Taoka Viscoelasticity of alkylphenol / sulfur chloride condensates such as “Tacchirol (registered trademark) AP, V-200” It is preferable to use a modifier.

  Among rubber blends suitable for carcass and belt members, the rubber component is preferably natural rubber alone or a blend with BR containing natural rubber as a main component. Further, as the filler, carbon black alone or a blend with silica containing carbon black as a main component is preferably used. Further, N, N′-bis (2-methyl-2-nitropropyl) -1,6-hexanediamine (“Sumifine (registered trademark) 1162” manufactured by Sumitomo Chemical Co., Ltd.), 5-nitroso-8-hydroxyquinoline ( NQ-58), bis (3-triethoxysilylpropyl) tetrasulfide (Si-69), bis (3-triethoxysilylpropyl) disulfide (Si-75), 1,6-bis (N, N′-di) Benzylthiocarbamoyldithio) -hexane (“KA9188” manufactured by Bayer), hexamethylene bisthiosulfate disodium salt dihydrate, 1,3-biscitraconimidomethylbenzene (“Parkalink 900” manufactured by Flexis), Taoka Viscoelasticity of alkylphenol / sulfur chloride condensates such as “Tacchirol (registered trademark) AP, V-200” It is preferable to use a modifier.

  Using the vulcanized rubber thus obtained, a pneumatic tire is produced by a usual method. That is, the rubber composition in the stage before the vulcanization treatment is extruded into a tread member, and is pasted and molded by a usual method on a tire molding machine to form a green tire. A tire can be obtained by heating and pressurizing.

  The fuel efficiency of the automobile equipped with the tire thus obtained is improved, and a reduction in fuel consumption can be achieved.

  EXAMPLES Hereinafter, although an Example, a test example, a manufacture example, etc. are given and this invention is demonstrated concretely, this invention is not limited to these.

Production Example 1: Sodium salt of S- [4- (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl) butyl] thiosulfuric acid The reaction vessel was purged with nitrogen, and N- (4-Chlorobutyl) phthalimide (10.00 g, 0.042 mol), sodium thiosulfate pentahydrate (10.44 g, 0.042 mol), methanol (50 ml) and water (50 ml) were charged, and the resulting mixture was stirred at 80 ° C. for 21 hours. Refluxed. The reaction mixture was allowed to cool, the solvent was completely removed under reduced pressure, 225 ml of ethanol was added, and the mixture was refluxed for 1 hour. By-product sodium chloride was removed by hot filtration. The filtrate was concentrated under reduced pressure until crystals precipitated, and then allowed to stand. The crystals were collected by filtration and washed with ethanol. The crystals obtained were dried in vacuo to give 14.2 g (0) of the sodium salt of S- [4- (1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl) butyl] thiosulfuric acid. 0.042 mol) was obtained.
¹ H-NMR (270.05 MHz, D ₂ O) δ _ppm : 1.7 (4H, p, J = 6.8 Hz), 3.0 (2H, t, J = 6.6 Hz), 3.6 ( 2H, t, J = 6.3 Hz), 7.6-7.7 (4H, m)

Production Example 2: Sodium salt of S- (4-aminobutyl) thiosulfuric acid The reaction vessel was purged with nitrogen, and then S- [4- (1,3-dihydro-1,3-dioxo-2H-isoindole- 2-yl) butyl] thiosulfuric acid sodium salt (14.2 g, 0.042 mol), hydrazine monohydrate (2.25 g, 0.045 mol), and ethanol (144 ml) were charged, and the resulting mixture was stirred at 76 ° C. for 5 hours. Refluxed. The reaction mixture was allowed to cool and the solvent was completely removed under reduced pressure, and then 72 ml of water was added. 1 mol / l hydrochloric acid (1N) was added to the aqueous solution to adjust the pH to 3 to 4, and the by-product phthalhydrazide was removed by filtration. A 1 mol / l sodium hydroxide solution (1N) was added to the filtrate to adjust the pH to 10 to 11, and then the solvent was completely removed under reduced pressure. 217 ml of ethanol was added to the concentrate and refluxed for 1 hour. By-product sodium chloride was removed by hot filtration. The filtrate was concentrated under reduced pressure until crystals precipitated, and then allowed to stand. The crystals were collected by filtration and washed with ethanol. The obtained crystals were vacuum-dried to obtain 4.0 g (0.019 mol) of sodium salt of S- (4-aminobutyl) thiosulfuric acid.
¹ H-NMR (270.05 MHz, D ₂ O) δ _ppm : 1.5 (2H, p, J = 14.5 Hz), 1.7 (2H, p, J = 14.8 Hz), 2.6 ( 2H, t, J = 7.3 Hz), 3.0 (2H, t, J = 7.3 Hz)

Example 1
<First step>
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of natural rubber (RSS # 1), 45 parts by weight of HAF (Asahi Carbon Co., Ltd., trade name “Asahi # 70”), 3 parts by weight of stearic acid Then, 5 parts by weight of zinc oxide and 1 part by weight of sodium salt of S- (4-aminobutyl) thiosulfuric acid obtained in Production Example 2 were kneaded and mixed to obtain a rubber composition. This process was carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time was 160 to 170 ° C.
<Second step>
The rubber composition obtained in the first step, 1 part by weight of sulfur accelerator (N-cyclohexyl-2-benzothiazolesulfenamide), sulfur at a temperature of 60 to 80 ° C. in an open roll machine 2 parts by weight and an antioxidant (N-phenyl-N′-1,3-dimethylbutyl-p-phenylenediamine: trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd.) 1 part by weight Thus, a rubber composition was obtained.
<Third step>
The rubber composition obtained in the second step was vulcanized at 145 ° C. to obtain a vulcanized rubber.

Reference example 1
In Example 1, a vulcanized rubber was obtained in the same manner as in Example 1 except that the sodium salt of S- (4-aminobutyl) thiosulfuric acid was not used.

Test example 1
Tensile properties and viscoelastic properties were measured as follows.
(1) Rebound resilience The resilience was measured using a Lupke type testing machine.
(2) Tensile properties Measurement was performed according to JIS-K6251.
The tensile stress (M ₁₀₀ ) was measured using a dumbbell No. 3 type.

(3) Viscoelastic property It measured using the viscoelasticity analyzer made by Ueshima Seisakusho.
Condition: Temperature -5 ° C to 80 ° C (Temperature increase rate: 2 ° C / min)
Initial strain 10%, dynamic strain 2.5%, frequency 10Hz

When the vulcanized rubber obtained in Reference Example 1 is used as a control, the vulcanized rubber obtained in Example 1 has a 6% improvement in resilience, a 7% improvement in tensile stress (M ₁₀₀ ), and a viscoelastic property (60 Tan δ) at 22 ° C. was reduced by 22%, and improvements in various physical properties were confirmed in all tests.

Example 2
A belt is obtained by covering the steel cord that has been subjected to the brass plating treatment with the kneaded material obtained in the second step of Example 1. A vulcanized tire is obtained by forming a green tire using the obtained belt according to a normal production method and heating and pressing the obtained green tire in a vulcanizer.

Example 3
The kneaded material obtained in the second step of Example 1 is extruded to obtain a tread member. Using the obtained tread member, a raw tire is formed according to a normal production method, and the obtained raw tire is heated and pressurized in a vulcanizer to obtain a vulcanized tire.

Example 4
The kneaded material obtained in the second step of Example 1 is extruded to prepare a kneaded material having a shape corresponding to the carcass shape, and a carcass is obtained by sticking the upper and lower sides of the polyester carcass fiber cord. . Using the obtained carcass, a raw tire is formed according to a normal production method, and the obtained raw tire is heated and pressurized in a vulcanizer to obtain a vulcanized tire.

Example 5
In the second step of Example 1, a vulcanized rubber is obtained in the same manner as in Example 1 except that 0.2 parts by weight of N- (cyclohexylthio) -phthalimide (CTP) is further kneaded and blended.

Example 6
The vulcanized rubber obtained by the following first to third steps is suitable for cap treads.
<First step>
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of styrene / butadiene copolymer rubber SBR # 1502 (manufactured by Sumitomo Chemical Co., Ltd.), ISAF-HM (manufactured by Asahi Carbon Co., Ltd., trade name “Asahi # 80”) ) 45 parts by weight, stearic acid 2 parts by weight, zinc oxide 3 parts by weight, S- (4-aminobutyl) thiosulfate sodium salt 1 part by weight, anti-aging agent (N-phenyl-N′-1,3-dimethyl) Butyl-p-phenylenediamine (6PPD): 1 part by weight of trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd. and 2 parts by weight of wax (“OZOACE-0355” manufactured by Nippon Seiwa) were kneaded and mixed. A rubber composition is obtained. This process is carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
The rubber composition obtained by the first step, 3 parts by weight of a vulcanization accelerator N-cyclohexyl-2-benzothiazolesulfenamide (CBS) at a temperature of 60 to 80 ° C. in an open roll machine; 2 parts by weight of sulfur is kneaded and mixed to obtain a kneaded product.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 7
The vulcanized rubber obtained by the following first to third steps is suitable for undertread.
<First step>
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of styrene / butadiene copolymer rubber SBR # 1502 (manufactured by Sumitomo Chemical Co., Ltd.), ISAF-HM (manufactured by Asahi Carbon Co., Ltd., trade name “Asahi # 80”) ) 35 parts by weight, stearic acid 2 parts by weight, zinc oxide 3 parts by weight, S- (4-aminobutyl) thiosulfate sodium salt 1 part by weight, anti-aging agent (N-phenyl-N′-1,3-dimethyl) Butyl-p-phenylenediamine (6PPD): 1 part by weight of trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd. and 2 parts by weight of wax (“OZOACE-0355” manufactured by Nippon Seiwa) were kneaded and mixed. A rubber composition is obtained. This process is carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
A rubber composition obtained by the first step at a temperature of 60 to 80 ° C. in an open roll machine, and 2 parts by weight of a vulcanization accelerator N-cyclohexyl-2-benzothiazolesulfenamide (CBS); A vulcanization accelerator diphenylguanidine (DPG) 0.5 part by weight, a vulcanization accelerator dibenzothiazyl disulfide (MBTS) 0.8 part by weight and 1 part by weight of sulfur are kneaded and mixed to obtain a kneaded product.
<Third step>
A vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 8
The vulcanized rubber obtained by the following first to third steps is suitable for a belt.
<First step>
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of natural rubber (RSS # 1), 45 parts by weight of HAF (Asahi Carbon Co., Ltd., trade name “Asahi # 70”), 3 parts by weight of stearic acid , 5 parts by weight of zinc oxide, 1 part by weight of sodium salt of S- (4-aminobutyl) thiosulfuric acid, 10 parts by weight of hydrous silica (“Nipsil (registered trademark) AQ” manufactured by Tosoh Silica Co., Ltd.), anti-aging agent 2 parts by weight of FR (“Antioxidant FR” manufactured by Matsubara Sangyo Co., Ltd.), 2 parts by weight of resorcin and 2 parts by weight of cobalt naphthenate are kneaded and mixed to obtain a rubber composition. It is carried out by kneading for 30 minutes at a rotation speed of a mixer of 50 rpm, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
The rubber composition obtained by the first step at a temperature of 60 to 80 ° C. with an open roll machine, and 1 weight of vulcanization accelerator N, N-dicyclohexyl-2-benzothiazolesulfenamide (DCBS) 1 part by weight, 6 parts by weight of sulfur and 3 parts by weight of a methoxylated methylol melamine resin (“SUMIKANOL 507AP” manufactured by Sumitomo Chemical Co., Ltd.) are kneaded and mixed to obtain a kneaded product.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 9
Vulcanized rubber obtained by the following first to third steps is suitable for an inner liner.
<First step>
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki), halogenated butyl rubber ("Br-IIR2255" manufactured by ExxonMobil) 100 parts by weight, GPF 60 parts by weight, stearic acid 1 part by weight, zinc oxide 3 parts by weight, 1 part by weight of sodium salt of S- (4-aminobutyl) thiosulfuric acid and 10 parts by weight of paraffin oil (“Diana Process Oil” manufactured by Idemitsu Kosan Co., Ltd.) are kneaded and mixed to obtain a rubber composition. This process is carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
The rubber composition obtained by the first step at a temperature of 60 to 80 ° C. in an open roll machine, 1 part by weight of an antioxidant (condensation product of aniline and acetone (TMDQ)), a vulcanization accelerator dibenzothia 1 part by weight of zircodisulfide (MBTS) and 2 parts by weight of sulfur are kneaded and mixed to obtain a kneaded product.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 10
The vulcanized rubber obtained by the following first to third steps is suitable for a side wall.
<First step>
Using a Banbury mixer (600 ml Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.), 40 parts by weight of natural rubber (RSS # 3), 60 parts of polybutadiene rubber (“BR150B” manufactured by Ube Industries), 50 parts by weight of FEF, and 2.5 parts by weight of stearic acid Parts, zinc oxide 3 parts by weight, sodium salt of S- (4-aminobutyl) thiosulfate 1 part by weight, anti-aging agent (N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (6PPD) : 2 parts by weight of trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd., 10 parts by weight of aromatic oil (“NC-140” manufactured by Cosmo Oil Co., Ltd.) and wax (“ 2 parts by weight of “Sannok (registered trademark) wax”) are kneaded and mixed to obtain a rubber composition. This process is carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
The rubber composition obtained by the first step and the vulcanization accelerator N-tert-butyl-2-benzothiazolylsulfenamide (BBS) 0.75 at a temperature of 60 to 80 ° C. in an open roll machine Part by weight and 1.5 parts by weight of sulfur are kneaded and mixed to obtain a kneaded product.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 11
The vulcanized rubber obtained by the following first to third steps is suitable for carcass.
<First step>
Using a Banbury mixer (600 ml Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.), 70 parts by weight of natural rubber (TSR20), 30 parts by weight of styrene / butadiene copolymer rubber SBR # 1502 (manufactured by Sumitomo Chemical), N339 (manufactured by Mitsubishi Chemical) 60 parts by weight, 2 parts by weight of stearic acid, 5 parts by weight of zinc oxide, 7 parts by weight of process oil (“Diana Process PS32” manufactured by Idemitsu Kosan Co., Ltd.) and 1 part by weight of sodium salt of S- (4-aminobutyl) thiosulfuric acid The rubber composition is obtained by kneading and blending. This process is carried out by kneading at a rotational speed of a mixer of 50 rpm for 5 minutes after charging various chemicals and fillers, and the rubber temperature at that time is 160 to 175 ° C.
<Second step>
The rubber composition obtained by the first step at a temperature of 60 to 80 ° C. in an open roll machine, and 1 part by weight of a vulcanization accelerator N-tert-butyl-2-benzothiazolylsulfenamide (BBS) 3 parts by weight of sulfur, anti-aging agent (N-phenyl-N′-1,3-dimethylbutyl-p-phenylenediamine (6PPD): trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd.) 1 weight Parts and 1 part by weight of an antioxidant (aniline and acetone condensate (TMDQ)) are kneaded and mixed to obtain a kneaded product.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 145 ° C.

Example 12
The vulcanized rubber obtained by the following first to third steps is suitable for cap treads.
<First step>
Using a Banbury mixer (600 ml Laboplast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of styrene / butadiene copolymer rubber SBR # 1500 (manufactured by JSR), silica (trade name: “Ultrasil (registered trademark) VN3-G” Degussa 78.4 parts by weight, carbon black (trade name “N-339” manufactured by Mitsubishi Chemical Corporation), 6.4 parts by weight, silane coupling agent (bis (3-triethoxysilylpropyl) tetrasulfide: trade name “ 6.4 parts by weight of Si-69 (manufactured by Degussa), 47.6 parts by weight of process oil (trade name “NC-140” manufactured by Cosmo Oil), anti-aging agent (N-phenyl-N′-1,3- Dimethylbutyl-p-phenylenediamine (6PPD): trade name “Antigen (registered trademark) 6C” manufactured by Sumitomo Chemical Co., Ltd.) 1.5 parts by weight, zinc oxide 2 parts by weight, 2 parts by weight of stearic acid and 3 parts by weight of sodium salt of S- (4-aminobutyl) thiosulfuric acid are kneaded and mixed to obtain a rubber composition. The process is operated in a temperature range of 70 ° C. to 120 ° C., kneaded at 80 rpm mixer speed for 5 minutes after charging various chemicals and fillers, and then kneaded at 100 rpm mixer speed for 5 minutes. To implement.
<Second step>
The rubber composition obtained by the first step and 1 part by weight of a vulcanization accelerator N-cyclohexyl-2-benzothiazolesulfenamide (CBS) at a temperature of 30 to 80 ° C. in an open roll machine. 1 part by weight of a sulfur accelerator diphenylguanidine (DPG), 1.5 parts by weight of a wax (trade name “Sannok (registered trademark) N” manufactured by Ouchi Shinsei Chemical Co., Ltd.) and 1.4 parts by weight of sulfur are kneaded and blended. A kneaded product is obtained.
<Third step>
Vulcanized rubber is obtained by heat-treating the kneaded product obtained in the second step at 160 ° C.

Example 13
In Example 12, it replaced with styrene butadiene copolymer rubber SBR # 1500 (made by JSR), and it used similarly to Example 12 except using solution polymerization SBR ("ASAPRENE (trademark)" Asahi Kasei Chemicals Co., Ltd.). A vulcanized rubber is obtained. This vulcanized rubber is suitable as a cap tread.

Example 14
In Example 12, SBR # 1712 (manufactured by JSR) was used instead of styrene-butadiene copolymer rubber SBR # 1500 (manufactured by JSR), the amount of process oil used was changed to 21 parts by weight, and zinc oxide was charged. Vulcanized rubber is obtained in the same manner as in Example 12 except that the timing is changed to the second step. This vulcanized rubber is suitable as a cap tread.

  The present invention can provide a method for improving the viscoelastic properties of a vulcanized rubber used for manufacturing a tire.

Claims (3)

Use of S- (4-aminobutyl) thiosulfuric acid or a metal salt thereof for improving viscoelastic properties of vulcanized rubber. The use according to claim 1, wherein the metal ion in the metal salt of S- (4-aminobutyl) thiosulfuric acid is lithium ion, sodium ion, potassium ion, cesium ion, cobalt ion, copper ion or zinc ion. The use according to claim 1, wherein the metal ion in the metal salt of S- (4-aminobutyl) thiosulfuric acid is a lithium ion, a sodium ion or a potassium ion.