JP2013124348A - Rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition for improving the anti-oxidizing effect sustainability of a vulcanized rubber composition.SOLUTION: The rubber composition includes an antioxidant for rubbers obtained by supporting an anti-oxidizing substance for rubbers on activated carbon not having a hydroxyl group, and a rubber component. The anti-oxidizing substance for rubbers is preferably a compound represented by formula (I), wherein Ris H or 1-13C alkyl. The antioxidant for rubbers preferably includes the activated carbon not having a hydroxyl group in an amount of 1-100 pts.mass per 10 pts.mass of the anti-oxidizing substance for rubbers.

Description

  The present invention relates to a rubber composition and the like.

  Patent Document 1 describes N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine as an anti-aging material for rubber.

JP 2007-238803 A

  In a vulcanized rubber composition containing the conventional rubber anti-aging substance itself as it is, the anti-aging effect may not always be sufficiently satisfactory in terms of sustainability.

As a result of intensive studies under these circumstances, the present inventors have reached the present invention.
1. It comprises a rubber anti-aging agent obtained by supporting a rubber anti-aging substance on activated carbon having no hydroxyl group (hereinafter sometimes referred to as “the anti-aging agent for rubber”) and a rubber component. Rubber composition (hereinafter sometimes referred to as “the rubber composition of the present invention”).

（式（Ｉ）中、Ｒ^１は、水素原子又は炭素数１〜１３のアルキル基を表す。） 2. 1. The rubber anti-aging substance is a compound represented by the formula (I): The rubber composition as described.

(In formula (I), R ¹ represents a hydrogen atom or an alkyl group having 1 to 13 carbon atoms.)

3. 1. The rubber anti-aging agent is an anti-aging agent for rubber containing 1 part by mass to 100 parts by mass of activated carbon having no hydroxyl group with respect to 10 parts by mass of the anti-aging substance for rubber. Or 2. The rubber composition as described.

4). 1. An anti-aging agent for rubber obtained by supporting an anti-aging agent for rubber on activated carbon having no hydroxyl group, a rubber component, and a crosslinking agent. ~ 3. The rubber composition according to any one of the above.

5. 4). A vulcanized rubber composition comprising the rubber composition described above.

6). 4). A tire produced by processing the described rubber composition.

7). 5. A tire belt comprising a steel cord coated with the vulcanized rubber composition described above.

8). 5. A carcass for tires comprising a carcass fiber cord coated with the vulcanized rubber composition described above.

9. 5. A tire sidewall, a tire inner liner, a tire cap tread, or a tire undertread comprising the vulcanized rubber composition described above.

  In the vulcanized rubber composition containing the rubber composition of the present invention, the durability of the anti-aging effect is improved.

It is a figure explaining the method for measuring the transfer amount of the antiaging substance for rubber | gum in a vulcanized rubber composition. It is an infrared absorption spectrum of activated carbon (B1) used for this invention.

<Rubber aging prevention substances>
The “anti-aging agent for rubber” in the present invention is an organic substance blended for the purpose of preventing the aging of the rubber product and extending its life. The “anti-aging agent for rubber” in the present invention is not particularly limited, and examples thereof include those described in pages 436 to 443 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. be able to. Specifically, for example, N-phenyl-N′-1,3-dimethylbutyl-p-phenylenediamine (6PPD), reaction product of aniline and acetone (TMDQ), poly (2,2,4-trimethyl-1) , 2-) Dihydroquinoline) (“Antioxidant FR” manufactured by Matsubara Sangyo Co., Ltd.), synthetic wax (paraffin wax, etc.), vegetable wax, compound represented by formula (I), or compound represented by formula (II) Etc.
Preferable examples include substances having a relatively low molecular weight (specifically, for example, a molecular weight of about 150 to 400).
More preferable examples include a compound represented by the formula (I) or a compound represented by the formula (II).

（式（Ｉ）中、Ｒ^１は、水素原子又は炭素数１〜１３のアルキル基を表す。）

(In formula (I), R ¹ represents a hydrogen atom or an alkyl group having 1 to 13 carbon atoms.)

（式（ＩＩ）中、Ｒ^２は、水素原子又は、炭素数１〜１３のアルキル基を表す。Ｒ^３は、水素原子又は、炭素数１〜１３のアルコキシ基を表す）

(In formula (II), R ² represents a hydrogen atom or an alkyl group having 1 to 13 carbon atoms. R ³ represents a hydrogen atom or an alkoxy group having 1 to 13 carbon atoms)

  More specifically, for example, N-isopropyl-N′-phenyl-p-phenylenediamine (IPPD), N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine (6PPD), ETMDQ ( 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) and 2,2,4-trimethyl-1,2-dihydroquinoline.

<Activated carbon having no hydroxyl group (hereinafter sometimes referred to as “activated carbon”)>
Activated carbon is produced through carbonization and activation using natural products such as coconut shell, coal, pitch, and wood as raw materials. The “activated carbon” used in the present invention is not particularly limited, but is preferably a chemical activated charcoal activated with a chemical such as phosphoric acid, zinc chloride, sodium hydroxide, etc. , Purified white birch, special white birch, etc.

<Method for producing anti-aging agent for rubber>
The antiaging agent for rubber is obtained by supporting an antiaging material for rubber on activated carbon.
As content of activated carbon in this anti-aging agent for rubber | gum, it is good to contain 1-100 mass parts of activated carbon with respect to 10 mass parts of anti-aging substances for rubber | gum, for example. More preferably, it is good to contain 1 mass part-50 mass parts with respect to 10 mass parts of antiaging substances for rubber | gum, for example. Particularly preferably, for example, 2 to 30 parts by mass may be contained with respect to 10 parts by mass of the rubber anti-aging substance.

  Although the manufacturing method of this anti-aging agent for rubber | gum is not specifically limited, For example, the method of following (1), the method of following (2), etc. can be mentioned.

(1): After the rubber anti-aging substance is dissolved in a solvent, activated carbon is added to the resulting solution to obtain a mixture. The solvent is then removed from the mixture and the solid is dried (and crushed). Here, the “solvent” is not particularly limited as long as it can dissolve the anti-aging substance for rubber and can be removed by distillation. For example, hydrocarbon solvents such as toluene, xylene, hexane, heptane, etc. And ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and alcohol solvents such as methanol, ethanol and isopropanol.

(2): After melting the anti-aging substance for rubber, activated carbon is added to the resulting melt to obtain a mixture. Next, a method of drying (and crushing) the mixture.

  In the method (1) and the method (2), examples of the amount of activated carbon include 1 part by mass to 100 parts by mass with respect to 10 parts by mass of the antiaging substance for rubber. Preferably, 1 mass part-50 mass parts are mentioned with respect to 10 mass parts of antiaging substances for rubber | gum, for example. More preferably, for example, 2 to 30 parts by mass can be mentioned with respect to 10 parts by mass of the anti-aging agent for rubber.

  It can be easily confirmed, for example, by a solvent extraction method that the anti-aging material for rubber is supported on activated carbon. Specifically, for example, after supporting an anti-aging material for rubber on activated carbon, the anti-aging material for rubber is solvent-extracted to determine the content of the anti-aging material for rubber. What is necessary is just to observe the presence or absence of a change compared with the amount of the anti-aging substance. By supporting the rubber anti-aging substance on the activated carbon, the rubber anti-aging substance is strongly adsorbed on the pores of the activated carbon, and as a result, the amount of the rubber anti-aging substance extracted by the solvent is reduced.

That activated carbon does not have a hydroxyl group can be confirmed by, for example, Fourier transform infrared spectroscopy. In the infrared absorption spectrum of activated carbon, if there is no absorption in the region of 3800 to 2700 cm ⁻¹ , which is the absorption band of the O—H group stretching vibration, it means that there is no hydroxyl group.

<Use of anti-aging agent for rubber>
The rubber composition of the present invention contains the antiaging agent for rubber and a rubber component. The rubber composition of the present invention is preferably obtained by kneading the rubber anti-aging agent and a rubber component. Kneading can be performed by a known method. The rubber composition of the present invention is, for example, a masterbatch that is used to produce a more uniform vulcanized rubber composition having a more uniform quality (usually, the rubber before the vulcanized rubber composition is produced). And a rubber composition containing a high-concentration anti-aging material for rubber, which is a granular material in which a component and a large amount of the anti-aging agent for rubber are pre-kneaded. The rubber composition of the present invention may be a kneaded rubber composition further containing a filler, zinc oxide, stearic acid, a crosslinking agent, a vulcanization accelerator component, and the like.

As content of the anti-aging agent for rubber | gum in this invention rubber composition, 0.1 mass part-990 mass parts can be mentioned with respect to 100 mass parts of rubber components, for example.
When the rubber composition of the present invention is a kneaded rubber composition further containing a filler, zinc oxide, stearic acid, a crosslinking agent, a vulcanization accelerator component, etc., the antiaging agent for the rubber in the rubber composition of the present invention As content of, for example, 0.1 mass part-50 mass parts can be mentioned with respect to 100 mass parts of rubber components, Preferably, 1 mass part-30 mass parts can be mentioned, for example. More preferably, for example, 2 to 20 parts by mass can be used.
When the rubber composition of the present invention is a masterbatch used for producing a vulcanized rubber composition, the content of the rubber anti-aging agent in the rubber composition of the present invention is, for example, 100 parts by mass of a rubber component. 11 parts by weight to 990 parts by weight, preferably 31 parts by weight to 990 parts by weight, and more preferably 51 parts by weight to 600 parts by weight. Particularly preferred examples include 60 parts by mass to 500 parts by mass.

  Examples of rubber components include natural rubber, epoxidized natural rubber, deproteinized natural rubber and other modified natural rubber, polyisoprene rubber (IR), styrene / butadiene copolymer rubber (SBR), polybutadiene rubber (BR), acrylonitrile. Examples include various synthetic rubbers such as butadiene copolymer rubber (NBR), isoprene / isobutylene copolymer rubber (IIR), ethylene / propylene-diene copolymer rubber (EPDM), and halogenated butyl rubber (HR). Preferable examples include natural rubber, highly unsaturated rubber such as styrene / butadiene copolymer rubber and polybutadiene rubber. More preferably, natural rubber etc. can be mentioned. 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 the natural rubber include grades of natural rubber such as RSS # 1, RSS # 3, TSR20, and SIR20.
Examples of the epoxidized natural rubber include those having a degree of epoxidation of 10 mol% to 60 mol% (specifically, for example, ENR25, ENR50, etc., manufactured by Kumpoulan Guthrie).
Examples of the deproteinized natural rubber include a deproteinized natural rubber having a total nitrogen content of 0.3% by mass or less.
As the modified natural rubber, for example, 4-vinylpyridine, N, N-dialkylaminoethyl acrylate (specifically, N, N-diethylaminoethyl acrylate, etc.), 2-hydroxy acrylate, etc. are reacted in advance with natural rubber. And modified natural rubber containing a polar group.

Examples of the styrene-butadiene copolymer rubber (SBR) include emulsion polymerization SBR and solution polymerization SBR described in pages 210 to 211 of the “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. Can be mentioned. As the rubber composition for tread, for example, solution polymerization SBR can be preferably mentioned. Further, for example, solution polymerization SBR in which molecular ends are modified using 4,4′-bis- (dialkylamino) benzophenone such as “Nippol (registered trademark) NS116” manufactured by Nippon Zeon Co., Ltd., “SL574” manufactured by JSR, etc. Solution-polymerized SBR having a molecular end modified with a tin halide compound of No. 1, commercially available products of silane-modified solution-polymerized SBR such as “E10” and “E15” manufactured by Asahi Kasei Corporation, lactam compounds, amide compounds, urea compounds, N, An N-dialkylacrylamide compound, an isocyanate compound, an imide compound, a silane compound having an alkoxy group (trialkoxysilane compound, etc.) and an aminosilane compound alone, or a silane compound having a tin compound and an alkoxy group, Alkylacrylamide compounds and silane compounds having alkoxy groups A solution polymerization SBR having a plurality of different compounds such as nitrogen, tin, silicon, or a plurality of elements at the molecular ends obtained by modifying the molecular ends, respectively. More preferred can be mentioned.
Further, an oil-added SBR obtained by adding an oil such as process oil or aroma oil after polymerization into emulsion polymerization SBR and solution polymerization SBR can be preferably exemplified as the rubber composition for tread.

Examples of the polybutadiene rubber (BR) include solution polymerization BR such as a high cis BR having 90% or more of cis 1,4 bond and a low cis BR having a cis bond of around 35%. Preferably, for example, low cis BR having a high vinyl content can be used. Furthermore, for example, “Nipol (registered trademark) BR 1250H” manufactured by Nippon Zeon, tin-modified BR, 4,4′-bis- (dialkylamino) benzophenone, tin halide compound, lactam compound, amide compound, urea compound, etc. , N, N-dialkylacrylamide compound, isocyanate compound, imide compound, silane compound having alkoxy group (trialkoxysilane compound, etc.), aminosilane compound alone, or silane having tin compound and alkoxy group A compound, a plurality of different compounds such as an alkylacrylamide compound and an alkoxy group-containing silane compound, or the like, and each of the molecular ends obtained by modifying the molecular ends is nitrogen, tin, or silicon, or , Solution polymerization BR having a plurality of these elements It can be cited more preferably.
These BR can be preferably mentioned as a rubber composition for a tread or a rubber composition for a sidewall. Usually, it is used in a blend of SBR and / or natural rubber. As the blend ratio, in the case of the rubber composition for tread, SBR and / or natural rubber is 60% by mass to 100% by mass, BR is 40% by mass to 0% by mass, etc. with respect to the total rubber mass. Can do. Moreover, in the case of the rubber composition for sidewalls, SBR and / or natural rubber may be 10% by mass to 70% by mass, BR may be 90% by mass to 30% by mass, etc. with respect to the total rubber mass. . Preferably, a blend of natural rubber 40% by mass to 60% by mass and BR 60% by mass to 40% by mass with respect to the total rubber mass. In this case, a blend of modified SBR and non-modified SBR and a blend of modified BR and non-modified BR are also preferable.

Examples of the filler include carbon black, silica, talc, clay, titanium oxide and the like that are usually used in the rubber field. Preferably, carbon black, silica, etc. are mentioned, for example. More preferably, carbon black etc. can be mentioned, for example.
Examples of the carbon black include those described on page 494 of “Rubber Industry Handbook <Fourth Edition>” edited by the Japan Rubber Association. Preferably, for example, HAF (High Abrasion Furnace), SAF (Super Abrasion Furnace), ISAF (Intermediate SAF), FEF (Fast Extrusion Furnace), MAF, GPF (General Purpose Furnace), SRF (Semi-Reinforcing Furnace), etc. Carbon black is mentioned.
In the case of tire tread rubber composition, CTAB (Cetyl Tri-methyl Ammonium Bromide) surface area 40m ² / g~250m ² / g, nitrogen adsorption specific surface area 20m ² / g~200m ² / g, particle size 10nm~50nm Preferably, carbon black can be mentioned. More preferably, for example, carbon black and the like is CTAB surface 70m ² / g~180m ² / g. Specifically, for example, in the ASTM standard, N110, N220, N234, N299, N326, N330, N330T, N339, N343, N351 and the like can be mentioned. Moreover, the surface treatment carbon black which made 0.1 mass%-50 mass% adhere the silica to the surface of carbon black can also be mentioned preferably. More preferably, for example, a combination of several fillers such as a combination of carbon black and silica is used.
In the case of the tire tread rubber composition, for example, carbon black alone or both carbon black and silica can be preferably mentioned.
In the case of the carcass rubber composition, the rubber composition for a side wall is, CTAB surface area of 20m ² / g~60m ² / g, it can be preferably exemplified a carbon black particle size 40 nm to 100 nm. Specifically, for example, in the ASTM standard, N330, N339, N343, N351, N550, N568, N582, N630, N642, N660, N662, N754, N762 and the like can be mentioned.

  Although the usage-amount of this filler is not specifically limited, For example, 5 mass parts-100 mass parts can be mentioned with respect to 100 mass parts of rubber components. In the case of using only carbon black as a filler, for example, 30 to 80 parts by mass is preferably cited with respect to 100 parts by mass of the rubber component. Moreover, when using together carbon black and a silica as a filler in a tread member use, 5-60 mass parts of carbon black is mentioned preferably with respect to 100 mass parts of rubber components, for example.

The silica used as a filler, for example, a CTAB specific surface area 50m ² / g~180m ² / g of silica, silica nitrogen adsorption specific surface area 50m ² / g~300m ² / g or the like. Specifically, for example, “AQ” and “AQ-N” manufactured by Tosoh Silica Co., Ltd., “Ultra Gil (registered trademark) VN3”, “Ultra Gil (registered trademark) 360”, and “Ultra Gil (registered trademark)” manufactured by Degussa. 7000 ”,“ Zeosil (registered trademark) 115GR ”,“ Zeosil (registered trademark) 1115MP ”,“ Zeosil (registered trademark) 1205MP ”,“ Zeosil (registered trademark) Z85MP ”manufactured by Rhodia, (Registered trademark) AQ "and the like. Further, for example, silica having a pH of 6 to 8, silica containing 0.2% by mass to 1.5% by mass of sodium, true spherical silica having a roundness of 1 to 1.3, silicone oil such as dimethyl silicone oil It is also preferable to blend an organosilicon compound containing an ethoxysilyl group, silica surface-treated with an alcohol such as ethanol or polyethylene glycol, silica having two or more different nitrogen adsorption specific surface areas, and the like.

Although the usage-amount of this filler is not specifically limited, For example, 10 mass parts-120 mass parts can be mentioned with respect to 100 mass parts of rubber components.
Moreover, when mix | blending a silica, it is good to mix | blend 5-50 mass parts of carbon black with respect to 100 mass parts of rubber components, for example. As a compounding ratio of silica / carbon black, the range of 0.7 / 1-1 / 0.1 can be mentioned, for example.
When silica is used as the filler, bis (3-triethoxysilylpropyl) tetrasulfide (“Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (“Si-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 capable of binding to silica, such as one or more silane coupling agents selected from the group consisting of triethoxysilane. Specifically, for example, bis (3-triethoxysilylpropyl) tetrasulfide (“Si-69” manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (“Si-75” manufactured by Degussa), 3 -Octanoylthiopropyltriethoxysilane ("NXT silane" manufactured by General Electronic Silicones) and the like can be mentioned.
Although the addition time of these compounds is not particularly limited, it is preferable to add to the rubber at the same time as the silica. As a compounding quantity, 2 mass%-10 mass% can be mentioned with respect to the mass of a silica, for example. Preferably, 7 mass%-9 mass% are mentioned, for example.
As compounding temperature at the time of compounding the above-mentioned compound with rubber, 80 ° C-200 ° C can be mentioned, for example. Preferably, 110 degreeC-180 degreeC is mentioned, for example.
When silica is used as the filler, for example, 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, a monohydric alcohol such as ethanol, butanol, or octanol, Divalent or higher alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol, polyether polyol, N-alkylamines, amino acids, liquid polybutadienes whose molecular ends are carboxyl-modified or amine-modified, etc. May be blended.

  As usage-amount of a zinc oxide, 1 mass part-15 mass parts can be mentioned with respect to 100 mass parts of rubber components, for example. Preferably, 1 mass part-8 mass parts are mentioned, for example.

  As a usage-amount of a stearic acid, 0.5 mass part-10 mass parts can be mentioned with respect to 100 mass parts of rubber components, for example. Preferably, 1 mass part-5 mass parts are mentioned, for example.

  As a crosslinking agent, sulfur etc. can be mentioned, for example. Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur. Preferably, powder sulfur etc. are mentioned. Moreover, when using for tire members with many sulfur amounts, such as a member for belts, an insoluble sulfur etc. can be mentioned preferably, for example. Note that the sulfur does not contain a vulcanization accelerator. As usage-amount of sulfur, 0.3 mass part-5 mass parts can be mentioned with respect to 100 mass parts of rubber components, for example. Preferably, 0.5 mass part-3 mass parts are mentioned, for example.

  Examples of the vulcanization accelerator include thiazole vulcanization accelerators and sulfenamide vulcanization accelerators described on pages 412 to 413 of “Rubber Industry Handbook <Fourth Edition>” edited by Japan Rubber Association. And guanidine vulcanization accelerators.

Specifically, for example, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N-dicyclohexyl-2- Examples include benzothiazolylsulfenamide (DCBS), 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), and diphenylguanidine (DPG). Also, morpholine disulfide, which is a known vulcanizing agent, can be used.
When carbon black is used as the filler, for example, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS), N, N It is preferable to use either dicyclohexyl-2-benzothiazolylsulfenamide (DCBS) or dibenzothiazyl disulfide (MBTS) and diphenylguanidine (DPG).
When silica and carbon black are used in combination as fillers, for example, N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (BBS) , N, N-dicyclohexyl-2-benzothiazolylsulfenamide (DCBS) or dibenzothiazyl disulfide (MBTS) and diphenylguanidine (DPG) are preferably used in combination.

Although it does not restrict | limit especially as a ratio of sulfur and a vulcanization accelerator, For example, sulfur / vulcanization accelerator = 2 / 1-1 / 2 can be mentioned by mass ratio.
EV vulcanization in which the mass ratio of sulfur / vulcanization accelerator, which is a method for improving heat resistance in a rubber member mainly composed of natural rubber, is 1 or less is preferably used in applications requiring improvement in heat resistance.

  In addition, you may mix | blend various compounding agents normally used in the rubber | gum field | area. Examples of such compounding agents include oils; fatty acids such as stearic acid; Coumarone resin G-90 (softening point: 80 ° C. to 100 ° C.) manufactured by Nikkaku Chemical, and process resin AC8 (softened) manufactured by Kobe Oil Chemical Co., Ltd. Coumarone-indene resin such as terpene resin, terpene / phenol resin, aromatic modified terpene resin, etc .; “Nikanol (registered trademark) HP-100” (softening point 105-105) manufactured by Mitsubishi Gas Chemical Co., Ltd. 125 ° C.) xylene / formaldehyde resin; rosin derivatives such as “Ester gum” series and “neotol” series manufactured by Arakawa Chemical Co .; hydrogenated rosin derivatives; novolac alkylphenol resins; resol alkylphenol resins; Resin; liquid polybutadiene;

  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.

<Vulcanized rubber composition containing anti-aging agent for rubber>
The vulcanized rubber composition containing the rubber anti-aging agent is usually obtained by heat-treating a rubber composition obtained by kneading the rubber anti-aging agent, a rubber component and a crosslinking agent. As temperature conditions in heat processing, 120 degreeC-180 degreeC can be mentioned, for example. The heat treatment may be usually performed at normal pressure or under pressure.

The vulcanized rubber composition containing the present antiaging agent for rubber is suitably used for tires. Examples of the tire include a pneumatic tire and a solid tire.
Further, the vulcanized rubber composition containing the present anti-aging agent for rubber is a tire belt comprising a steel cord coated with each member constituting the tire, that is, a vulcanized rubber composition containing the present anti-aging agent for rubber. , A tire carcass including a carcass fiber cord coated with a vulcanized rubber composition containing the rubber anti-aging agent, a tire sidewall including a vulcanized rubber composition containing the rubber anti-aging agent, and a tire inner It is also preferably used as a liner, a tire tread or a tire undertread.

  The vulcanized rubber composition containing the present antiaging agent for rubber can extend the life of rubber materials such as tires. Further, the vulcanized rubber composition can be used not only for the above-mentioned tire use, but also as an anti-vibration rubber for automobiles such as engine mounts, strut mounts, bushes, and exhaust hangers.

EXAMPLES Hereinafter, although an Example, a reference example, a comparative example, etc. are given and this invention is demonstrated concretely, this invention is not limited to these.
<Rubber aging prevention substances>
A1: Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
<Activated carbon>
B1: Special white birch made by Nippon Enviro Chemicals

Production Example 1 (Production example of anti-aging agent for rubber)
A 300 ml round bottom flask was charged with 20 parts by mass of rubber anti-aging substance (A1) and dissolved in 160 parts by mass of methanol. 20 parts by mass of activated carbon (B1) was added to a methanol solution in which the antiaging substance for rubber (A1) was dissolved, and the resulting mixture was stirred at room temperature under nitrogen for 24 hours. This mixture was evaporated to obtain the rubber anti-aging agent (1) as a black solid.

In addition, the content rate of the anti-aging substance for rubber | gum in this anti-aging agent for rubber | gum was confirmed with the following method.
<Method of extracting anti-aging substances for rubber>
1. A mixed solution (mass ratio 1: 1) of 1M KCl aqueous solution and acetone was prepared.
2. The rubber anti-aging agent 0.5 g was weighed in a beaker.
3. 2. The above 1. 100 mL of the solution obtained in the above was added, and the resulting mixture was subjected to ultrasonic irradiation (irradiation time was 30 minutes, 60 minutes, and 90 minutes).
4). 3. above. The mixture obtained in was filtered with suction. The filter cake was washed until the color of the rubber anti-aging substance (red) disappeared. Such an operation was performed to collect the filtrate.
5. 4. above. From the filtrate collected in step 1, the solvent was distilled off under reduced pressure using an evaporator to obtain a concentrate.
6). 5. above. By adding dimethylformamide to the concentrate obtained in step 50, a 50 mL solution was obtained.
7). Above 6. The solution obtained in the above was subjected to liquid chromatography (LC) (mobile phase: phosphate buffer / acetonitrile / water system).
8). The content of the anti-aging agent for rubber in the anti-aging agent for rubber was calculated from the following formula.
<Calculation formula>
Content of anti-aging substances for rubber in this anti-aging agent for rubber (actual value) (%)
= ((UV detection peak area of anti-aging agent for rubber on LC) -5385.7) / 1324900

About the anti-aging agent for rubber obtained in the production example, the content of the anti-aging material for rubber confirmed by the above extraction method was compared with the theoretical value. The theoretical value is a value calculated by the following method.
<Calculation formula>
Content of rubber anti-aging substances (theoretical value) (%)
= 100 x (Rubber anti-aging substance charge) / (Rubber anti-aging substance charge + Activated carbon charge)
Table 1 shows the value of the content (%) of the anti-aging agent for rubber obtained with respect to the anti-aging agent for rubber (1) obtained in Production Example 1.

(Method for confirming that activated carbon used in the present invention has no hydroxyl group)
In the infrared absorption spectrum of the activated carbon (B1), no absorption due to OH group stretching vibration was observed, so it was confirmed that there was no hydroxyl group.

[Measurement conditions for infrared spectroscopy]
Apparatus: Fourier transform infrared spectrophotometer Varian 670-IR [manufactured by VARIAN]
Measurement method: Diffuse reflection method Correction function: Kubelka-Munk function

Reference Example 1 (Production example of basic rubber composition)
Into a 10 L kneader, 50 parts by mass of both natural rubber (product name: SMR-CV60) and butadiene rubber (product name: JSR BR01, manufactured by JSR Corporation) were added and kneaded for 2 minutes. After adding the materials shown in Table 2 to the obtained kneaded product, the mixture was further kneaded for 10 minutes to obtain a rubber composition as a basic rubber composition. The discharge temperature of the rubber composition from the kneader was 95 ° C.

Comparative Example 1 (Production Example of Vulcanized Rubber Composition not Containing Anti-aging Agent for Rubber)
163.5 parts by mass of the basic rubber composition obtained in Reference Example 1, 2 parts by mass of zinc oxide, and a vulcanization accelerator (N-tert-butyl-2-benzothiazolesulfenamide (TBBS)) 0.8 A rubber composition was obtained by kneading parts by mass and 1.5 parts by mass of sulfur with an open roll machine having a roll set temperature of 60 ° C. The obtained rubber composition was hot press molded at 145 ° C. Thus, a vulcanized rubber composition containing 15.5 cm in width, 16.0 cm in length and 2 mm in thickness, which does not contain this rubber anti-aging agent (however, both an anti-aging agent for rubber and activated carbon are added). includes not) was obtained. Incidentally, between 90% vulcanization of the measured rubber composition in conformity with JIS K 6300-2 to _(t c (90)) than the extended 5 minutes time and the vulcanization time.
Next, 163.5 parts by mass of the basic rubber composition obtained in Reference Example 1, 2 parts by mass of zinc oxide, and a vulcanization accelerator (N-tert-butyl-2-benzothiazolesulfenamide (TBBS)) A rubber composition was obtained by kneading 0.8 parts by mass, 1.5 parts by mass of sulfur, and 3 parts by mass of an anti-aging agent for rubber (A1) with an open roll machine having a roll set temperature of 60 ° C. . The obtained rubber composition is heated and press-molded at 145 ° C. to form a vulcanized rubber composition containing no anti-aging agent for rubber in the form of a sheet having a width of 15.5 cm, a length of 16.0 cm, and a thickness of 2 mm. (However, it contains a rubber anti-aging substance and does not contain activated carbon). Incidentally, between 90% vulcanization of the measured rubber composition in conformity with JIS K 6300-2 to _(t c ₍₉₀₎₎ than the extended 5 minutes time and the vulcanization time.

Reference Example 2 (Method for measuring the migration amount of anti-aging substances for rubber)
Vulcanized rubber composition not containing anti-aging agent for rubber (however, it does not contain both anti-aging substance for rubber and activated carbon) and vulcanized rubber composition not containing anti-aging agent for rubber (however, rubber The amount of migration of the anti-aging substance for rubber was measured using an anti-aging substance for use and no activated carbon).
Three sheets manufactured from a vulcanized rubber composition that does not contain the rubber anti-aging agent (but does not contain both the rubber anti-aging substance and activated carbon), and a rubber that does not contain the rubber anti-aging agent. The initial weight of each sheet was measured for three sheets produced from a vulcanized rubber composition (however, containing an antiaging substance for rubber and not containing activated carbon).
FIG. 1 is a diagram for explaining a method for measuring the amount of migration of a rubber anti-aging substance in a vulcanized rubber composition. 6 sheets after weight measurement (sheets 1 to 3 produced from a vulcanized rubber composition containing the present anti-aging agent for rubber, sheets produced from a vulcanized rubber composition not containing the present anti-aging agent for rubber) After laminating 4 to 6), the entire laminate was wrapped with aluminum foil 7 and further wrapped with aluminum laminate 8 from above. About 3 kg of weights 9 were placed on the aluminum foil and aluminum laminate package thus obtained.
The package on which the weight was placed was left in a thermostatic chamber at 25 ° C. for 6 days, then the aluminum foil and the aluminum laminate package were opened, each sheet was taken out, and the weight of each sheet was measured.
The amount of migration of the anti-aging agent for rubber was defined as a change in weight from the initial weight of the sheet produced from the vulcanized rubber composition not containing the anti-aging agent for rubber. Separately, as a result of extracting and quantifying the anti-aging agent for rubber from the vulcanized rubber composition of each sheet, it was confirmed that the weight change was caused by the migration of the anti-aging agent for rubber.

Example 1 (Production Example of Vulcanized Rubber Composition Containing Anti-aging Agent for Rubber)
163.5 parts by mass of the basic rubber composition obtained in Reference Example 1, 2 parts by mass of zinc oxide, and a vulcanization accelerator (N-tert-butyl-2-benzothiazolesulfenamide (TBBS)) 0.8 By kneading 6 parts by mass of the rubber anti-aging agent (1) obtained in Production Example 1 with 6 parts by mass of sulfur, 1.5 parts by mass of sulfur using an open roll machine having a roll set temperature of 60 ° C., rubber is obtained. A composition was obtained. The resulting rubber composition is heated and press-molded at 145 ° C. to form a vulcanized rubber composition containing the present antioxidant for rubber in the form of a sheet having a width of 15.5 cm, a length of 16.0 cm, and a thickness of 2 mm. Got. Incidentally, between 90% vulcanization of the measured rubber composition in conformity with JIS K 6300-2 to _(t c ₍₉₀₎₎ than the extended 5 minutes time and the vulcanization time.

(Production example of vulcanized rubber composition not containing anti-aging agent for rubber)
On the other hand, 163.5 parts by mass of the basic rubber composition obtained in Reference Example 1, 2 parts by mass of zinc oxide, and a vulcanization accelerator (N-tert-butyl-2-benzothiazolesulfenamide (TBBS)] 0 A rubber composition was obtained by kneading 0.8 parts by mass and 1.5 parts by mass of sulfur with an open roll machine having a roll set temperature of 60 ° C. The obtained rubber composition was heated and pressed at 145 ° C. By molding, a vulcanized rubber composition containing 15.5 cm in width, 16.0 cm in length and 2 mm in thickness and containing no anti-aging agent for rubber (however, an anti-aging agent for rubber and activated carbon) was obtained does not contain both). Incidentally, the inter 90% vulcanization time _(t c (90)) pressurizing a more extended time 5 minutes vulcanization of measured rubber composition in conformity with JIS K 6300-2 did.
Using the vulcanized rubber composition containing the rubber anti-aging agent and the vulcanized rubber composition not containing the rubber anti-aging agent (but not including both the rubber anti-aging substance and activated carbon) In the same manner as in Example 2, the amount of migration of the rubber anti-aging substance was measured.

The results obtained are summarized in Table 4.
“Transition rate of anti-aging agent for rubber” described in Table 4 is a vulcanized rubber composition not containing the anti-aging agent for rubber obtained in Comparative Example 1 (however, an anti-aging agent for rubber is added). It is a relative transfer amount of the anti-aging material for rubber in the examples when the transfer amount of the anti-aging material for rubber in the case of (including activated carbon and not including activated carbon) is defined as 100. The smaller the value, the slower the migration rate of the anti-aging material for rubber, which means that the durability of the anti-aging effect in the vulcanized rubber composition is improved.

Reference Example 3 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for undertread.
<First step>
(Procedure 1)
Using a Banbury mixer (600ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by mass 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 mass, 2 parts by mass of stearic acid, 3 parts by mass of zinc oxide, 4 parts by mass of the antiaging agent for rubber obtained in Production Example 1 (1) and wax (“OZOACE-0355” manufactured by Nippon Seiwa) 2 A rubber composition is obtained by kneading a mass part within a range of 160 ° C. to 175 ° C. for 5 minutes at a rotation speed of a mixer of 50 rpm.
(Procedure 2)
The rubber composition obtained in step 1 and 2 parts by mass of N-cyclohexyl-2-benzothiazolesulfenamide (CBS) as a vulcanization accelerator within the range of 60 ° C. to 80 ° C. in an open roll machine. By kneading 0.5 parts by mass of diphenylguanidine (DPG) as a vulcanization accelerator, 0.8 parts by mass of dibenzothiazyl disulfide (MBTS) as a vulcanization accelerator and 1 part by mass of sulfur, rubber was obtained. A kneaded product is obtained.
<Second step>
The rubber kneaded material obtained in the first step (procedure 2) is heat-treated at 145 ° C. to obtain a vulcanized rubber composition.

Reference Example 4 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for a belt.
<First step>
(Procedure 1)
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by mass of commercially available natural rubber (RSS # 1), 45 parts by mass of HAF (Asahi Carbon Co., Ltd., trade name “Asahi # 70”), stearic acid 3 Parts by mass, zinc oxide 5 parts by mass, hydrous silica (“Nipsil (registered trademark) AQ” manufactured by Tosoh Silica Co., Ltd.) 10 parts by mass, anti-aging agent for rubber obtained in Production Example 1 (1) 8 parts by mass, resorcin A rubber composition is obtained by kneading 2 parts by mass and 2 parts by mass of cobalt naphthenate within a range of 160 ° C. to 175 ° C. for 5 minutes at a rotation speed of a mixer of 50 rpm.
(Procedure 2)
The rubber composition obtained in Procedure 1 and N, N-dicyclohexyl-2-benzothiazolesulfenamide (DCBS) 1 as a vulcanization accelerator within the range of 60 ° C. to 80 ° C. in an open roll machine. A rubber kneaded material is obtained by kneading 3 parts by mass of 6 parts by mass of sulfur, 6 parts by mass of sulfur, and 3 parts by mass of a methoxylated methylol melamine resin (“SUMIKANOL 507AP” manufactured by Sumitomo Chemical Co., Ltd.).
<Second step>
The rubber kneaded material obtained in the first step (procedure 2) is heat-treated at 145 ° C. to obtain a vulcanized rubber composition.

Reference Example 5 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for an inner liner.
<First step>
(Procedure 1)
Using a Banbury mixer (600 ml Lab Plast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by mass of halogenated butyl rubber (“Br-IIR2255” manufactured by ExxonMobil), 60 parts by mass of GPF, 1 part by mass of stearic acid, 3 parts by mass of zinc oxide and A rubber composition is obtained by kneading 10 parts by mass of paraffin oil (“Diana Process Oil” manufactured by Idemitsu Kosan Co., Ltd.) within a range of 160 ° C. to 175 ° C. for 5 minutes at a rotation speed of a mixer of 50 rpm.
(Procedure 2)
In the range of 60 to 80 ° C. with an open roll machine, the rubber composition obtained in Procedure 1, the anti-aging agent for rubber (1) obtained in Production Example 1, 1 part by mass, and a vulcanization accelerator A rubber kneaded product is obtained by kneading 1 part by mass of a certain dibenzothiazyl disulfide (MBTS) and 2 parts by mass of sulfur.
<Second step>
A vulcanized rubber composition is obtained by heat-treating the kneaded product obtained in the first step (procedure 2) at 145 ° C.

Reference Example 6 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for side walls.
<First step>
(Procedure 1)
Using a Banbury mixer (600 ml Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.), 40 parts by mass of commercially available natural rubber (RSS # 3), 60 parts by mass of polybutadiene rubber (“BR150B” manufactured by Ube Industries, Ltd.), 50 parts by mass of FEF, and stearic acid 2 0.5 parts by mass, 3 parts by mass of zinc oxide, 8 parts by mass of the antiaging agent for rubber (1) obtained in Production Example 1, 10 parts by mass of aromatic oil (“NC-140” manufactured by Cosmo Oil Co., Ltd.) and wax A rubber composition was obtained by kneading 2 parts by mass (“Sannok (registered trademark) wax” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) within the range of 160 ° C. to 175 ° C. for 5 minutes at a rotation speed of a mixer of 50 rpm. Get things.
(Procedure 2)
The rubber composition obtained in Procedure 1 and N-tert-butyl-2-benzothiazolylsulfenamide (BBS) 0. A rubber kneaded material is obtained by kneading 75 parts by mass and 1.5 parts by mass of sulfur.
<Second step>
The rubber kneaded material obtained in the first step (procedure 2) is heat-treated at 145 ° C. to obtain a vulcanized rubber composition.

Reference Example 7 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for carcass.
<First step>
(Procedure 1)
Using a Banbury mixer (600 ml Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.), 70 parts by mass of commercially available natural rubber (TSR20), 30 parts by mass of styrene / butadiene copolymer rubber SBR # 1502 (manufactured by Sumitomo Chemical), N339 (Mitsubishi Chemical Corporation) 60 parts by mass, 2 parts by mass of stearic acid, 5 parts by mass of zinc oxide and 7 parts by mass of process oil (“Diana Process PS32” manufactured by Idemitsu Kosan Co., Ltd.) within a range of 160 ° C. to 175 ° C. for 5 minutes, 50 rpm A rubber composition is obtained by kneading at a rotational speed of the mixer.
(Procedure 2)
The rubber composition obtained in Procedure 1 and N-tert-butyl-2-benzothiazolylsulfenamide (BBS) 1 mass as a vulcanization accelerator within the range of 60 ° C. to 80 ° C. in an open roll machine. A rubber kneaded product is obtained by kneading 4 parts by mass of 3 parts by mass of sulfur, 3 parts by mass of sulfur, and 4 parts by mass of the antiaging agent for rubber (1) obtained in Production Example 1.
<Second step>
The rubber kneaded product obtained in the first step (procedure 2) is heat-treated at 145 ° C. to obtain a vulcanized rubber.

Reference Example 8 (Production Example of Vulcanized Rubber Composition)
The vulcanized rubber composition obtained by the following first step and second step is suitable for cap treads.
<First step>
(Procedure 1)
Using a Banbury mixer (600 ml Laboplast Mill manufactured by Toyo Seiki Co., Ltd.), 100 parts by mass of styrene / butadiene copolymer rubber SBR # 1500 (manufactured by JSR), silica (trade name: “Ultrasil (registered trademark) VN3-G” Degussa 78.4 parts by mass, carbon black (trade name “N-339” manufactured by Mitsubishi Chemical Corporation), 6.4 parts by mass, silane coupling agent (bis (3-triethoxysilylpropyl) tetrasulfide: trade name “ 6.4 parts by mass of Si-69 “manufactured by Degussa), 47.6 parts by mass of process oil (trade name“ NC-140 ”manufactured by Cosmo Oil Co., Ltd.), anti-aging agent for rubber obtained in Production Example 1 (1 ) 6 parts by mass and 2 parts by mass of zinc oxide were kneaded in the range of 70 ° C. to 120 ° C. for 5 minutes at the rotation speed of the mixer of 80 rpm, and subsequently in the range of 70 ° C. to 120 ° C. In 5 minutes, by kneading at a rotation speed of 100rpm of mixer to obtain a rubber composition.
(Procedure 2)
The rubber composition obtained in step 1 and 1 part by mass of N-cyclohexyl-2-benzothiazolesulfenamide (CBS) as a vulcanization accelerator within the range of 30 ° C. to 80 ° C. in an open roll machine 1 part by weight of diphenylguanidine (DPG) as a vulcanization accelerator, 1.5 parts by weight of wax (trade name “Sannok (registered trademark) N” manufactured by Ouchi Shinsei Chemical Co., Ltd.) and 1.4 parts by weight of sulfur By kneading, a rubber kneaded product is obtained.
<Second step>
The rubber kneaded material obtained in the first step (procedure 2) is heat-treated at 160 ° C. to obtain a vulcanized rubber composition.

Reference Example 9 (Production Example of Vulcanized Rubber Composition)
In Reference Example 8, the same procedure as in Reference Example 8 was used, except that solution-polymerized SBR (“ASAPrene (registered trademark)” manufactured by Asahi Kasei Chemicals) was used instead of styrene-butadiene copolymer rubber SBR # 1500 (manufactured by JSR). Thus, a vulcanized rubber composition is obtained. The obtained vulcanized rubber composition is suitable as a cap tread.

Reference Example 10 (Production Example of Vulcanized Rubber Composition)
In Reference Example 8, in place of styrene / butadiene copolymer rubber SBR # 1500 (manufactured by JSR), SBR # 1712 (manufactured by JSR) was used, the amount of process oil used was changed to 21 parts by mass, and zinc oxide was charged. A vulcanized rubber composition is obtained in the same manner as in Reference Example 8 except that the timing is changed to Procedure 2. The obtained vulcanized rubber composition is suitable as a cap tread.

  In the vulcanized rubber composition containing the rubber composition of the present invention, the durability of the anti-aging effect is improved.

1,2,3 Sheets manufactured from a vulcanized rubber composition containing an antioxidant for rubber 4,5,6 Sheets 7 manufactured from a vulcanized rubber composition not containing an antioxidant for rubber 7 Aluminum foil 8 Aluminum laminate 9 weight

Claims (9)

  A rubber composition comprising a rubber anti-aging agent obtained by supporting a rubber anti-aging substance on activated carbon having no hydroxyl group and a rubber component. The rubber composition according to claim 1, wherein the rubber anti-aging substance is a compound represented by the formula (I).

(In formula (I), R ¹ represents a hydrogen atom or an alkyl group having 1 to 13 carbon atoms.)   The anti-aging agent for rubber is an anti-aging agent for rubber containing 1 to 100 parts by mass of activated carbon having no hydroxyl group with respect to 10 parts by mass of the anti-aging agent for rubber. Or the rubber composition of 2.   The anti-aging agent for rubber, an anti-aging agent for rubber obtained by carrying on an activated carbon having no hydroxyl group, a rubber component, and a cross-linking agent are contained. Rubber composition.   A vulcanized rubber composition comprising the rubber composition according to claim 4.   A tire manufactured by processing the rubber composition according to claim 4.   A tire belt comprising a steel cord coated with the vulcanized rubber composition according to claim 5.   A carcass for tires comprising a carcass fiber cord coated with the vulcanized rubber composition according to claim 5.   A tire sidewall, a tire inner liner, a tire cap tread, or a tire undertread comprising the vulcanized rubber composition according to claim 5.

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