JP2002338753A - Rubber composition having improved wet skid resistance and rolling resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition having good wet skid resistance and low rolling resistance obtained by incorporating an easily producible compounding ingredient into a rubber. SOLUTION: The rubber composition having good wet skid resistance and low rolling resistance comprises a rubber and a composite composed of an oxidative condensate obtained by subjecting a compound having a π-electron aromatic ring to oxidative condensation and carbon black. A pneumatic tire uses the rubber composition in a tire tread.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber composition, and more particularly, to a rubber composition having good wet skid resistance and low rolling resistance in which a compounding agent which is easy to produce is mixed with rubber. .

[0002]

2. Description of the Related Art With the advancement of high performance and high function of automobiles, the required performance of tires is becoming higher year by year. As one of them, there is a strong demand for the development of a tire that has a grip force on a wet road surface, that is, a good wet skid resistance, and also has low fuel consumption. In order to obtain a fuel-efficient tire, it is necessary to use a tire having a small hysteresis loss. However, when the hysteresis loss is reduced, the rolling resistance is reduced, and the grip force is reduced, which is a problem in running safety. On the other hand, if the wet skid resistance is increased in order to increase the grip force, the rolling resistance, that is, the hysteresis loss increases, resulting in a tire with poor fuel economy.

As described above, since wet skid resistance and rolling resistance are in a trade-off relationship, studies on rubber compositions for tires that satisfy both are actively conducted. Various compounding agents to be added to the rubber composition have been reported as rubber compositions for tires having high wet skid resistance despite low rolling resistance.

[0004] Nitroso compounds have been reported as compounding agents for improving the dynamic behavior as described above, but there is a problem that nitrosamine compounds have a bad effect on the human body, and the production has been discontinued at present. (Kenneth W. Doa
k et al.; Rubber Chem. Technol., 28, 895 (1995),
Payne, AR et al.; J. Rubber Res. Inst. Malaya,
22, 275 (1969), Walker, LA et al.; Rubber Age
90, 925 (1962), Patts, KT et al., Rubber Chem.
Technol., 47, 289 (1974), Daneil F. Graves; Rubber
Chem. Technol., 66, 61 (1993)) Also, dinitroamine compounds have been reported as other compounding agents. However, it has been reported that the above-mentioned improvement in the dynamic behavior is observed for polyisoprene rubber but not for butadiene rubber such as SBR. (Yamaguchi, T. et al .; Kau
See, tsch. Gummi. Kunstst., 42, 403 (1989)) A dialkylamino group-containing sulfur compound (Japanese Patent Application Laid-Open No. 9-278942) is used as a compounding agent which exhibits the above-mentioned effects on polyisoprene rubber and butadiene rubber. ) Or aminobenzenesulfonyl azide (Gonzalez, L. et al.; Ru
bber Chem. Technol., 69, 266 (1996)). However, these compounds have drawbacks in that the production process is complicated over many steps, and that the latter azide compound is explosive and uses sodium azide which requires careful handling as a raw material for synthesis.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rubber composition having good wet skid resistance and low rolling resistance in which a compounding agent which is easy to produce is blended with rubber. It is in.

[0006]

According to the present invention, (i)
A rubber composition comprising 100 to 100 parts by weight of a rubber and (ii) 10 to 180 parts by weight of a composite comprising carbon black and an oxidized condensate obtained by oxidatively condensing a compound having a π-electron aromatic ring, and the rubber composition comprising The used pneumatic tire is provided.

[0007]

According to the present invention, (a) an oxidized condensate obtained by oxidatively condensing a compound having a π-electron aromatic ring (hereinafter, also referred to as “oxidized condensate” of the present invention); By compounding a composite comprising carbon black (hereinafter, also referred to as “composite” of the present invention) into a rubber composition,
In addition to obtaining good wet skid resistance and low rolling resistance, the composite of the present invention is a highly industrially practical compounding agent because it is easy to produce.

The compound having a π-electron aromatic ring used in the present invention is not particularly limited as long as it can form the oxidized condensate of the present invention with an oxidizing agent. Examples of the compound include aniline, naphthylamine, phenylenediamine, naphthylenediamine, and the like. Triaminobenzene, triaminonaphthalene, pyrrole, indole, carbazole, thiophene, selenophene, imidazole, furan, benzene,
Examples include azulene, pyrene, triphenylene, fluorene, benzenedithiol, diphenyldisulfide, phenol, diethynylbenzene, and derivatives thereof. As the derivative, for example, carbon number 1-30
An alkyl group, an alkoxy group having 1 to 30 carbon atoms, and 1 carbon atom
Alkylene oxide group, sulfonic acid group, alkylene sulfonic acid group having 1 to 30 carbon atoms, hydroxyl group, nitro group, amino group, cyano group, (di) alkylamino group (alkyl group has 1 to 30 carbon atoms), etc. And a compound in which one or more substituents are introduced on an aromatic ring. The above compounds may be used alone or in combination of two or more.

The oxidizing agent used in the present invention is not particularly limited as long as it can form the oxidized condensate of the present invention by oxidatively condensing the compound having a π-electron aromatic ring. Examples thereof include ammonium persulfate and persulfate. Persulfates such as potassium; trivalent iron salts such as iron (III) chloride, iron (III) sulfate and iron (III) nitrate; divalent copper salts such as copper (II) chloride; potassium permanganate, permanganate Permanganates such as sodium phosphate; dichromates such as potassium dichromate and sodium dichromate; peroxides such as hydrogen peroxide and peracetic acid; oxygen;
Ozone, oxidase (eg Liu, W. et al .; J. Am. Ch.
em. Soc. 1999, 121 , 71) and the like. Also, a redox-based initiator composed of an iron (II) salt and hydrogen peroxide, a Lewis acid (aluminum trichloride, iron trichloride, etc.) and an oxidizing agent (copper salt (cuprous chloride, secondary chloride) (Such as copper) and air (oxygen) can also be used (eg, Toshima, N. et a
l.; Chem. Lett. 2000, 1428 and Toshima, N.; Makromo
l. Chem., Macromol. Symp. 1992, 59, 123). The oxidizing agents may be used alone or in combination of two or more. The amount of the oxidizing agent to be added is preferably 0.005 to 20, more preferably 0.01 to 10, in terms of a molar ratio to the compound having a π-electron aromatic ring (oxidizing agent / compound having a π-electron aromatic ring).

As the oxidized condensate of the present invention, a compound obtained by previously oxidizing and condensing the above-mentioned compound having a π-electron aromatic ring may be used. It may be condensed, or may be bonded to carbon black simultaneously with oxidative condensation. As the oxidized condensate, the above π
The compound is not particularly limited as long as it is obtained by oxidatively condensing a compound having an electron aromatic ring. In particular, aniline, pyrrole, thiophene and their derivatives are preferably oxidatively condensed.

An example of the oxidized condensate of the present invention is a π-conjugated polymer compound, which is a polymer compound in which a large number of conjugated double bonds are introduced into the polymer main chain, and which has conductivity by doping treatment. It is known for showing. Examples of such a π-conjugated polymer compound include polyalinine, polypyrrole, polythiophene, poly (p-phenylene), poly (p-phenylenevinylene), and derivatives thereof. Polyaniline and its derivatives polymethylaniline, polythiophene, polypyrrole, and poly (p-phenylene) are preferred because they are versatile and economical.

[0012]

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(In each of the above formulas, n is 1 to 1000.) The oxidized condensate of the present invention is preferably bound to the composite of the present invention in an amount of 0.01 to 30% by weight, more preferably 0.05 to 25% by weight. preferable.
This is because by setting the content to 0.01% by weight or more, further effects of the present invention can be obtained, and even if the content exceeds 30% by weight, it is difficult to obtain an additional effect.

The carbon black used in the present invention is not particularly limited as long as it is a carbon black which is usually blended with rubber, but has a nitrogen specific surface area (N ₂ SA) of 20 to 20.
The carbon black of 0 m ² / g is preferred in terms of good processability and reinforcement when compounded with rubber, and examples thereof include SAF, ISAF, HAF, FEF and GPF grade carbon black.

The composite of the present invention is a composite in which an oxidized condensate obtained by oxidatively condensing a compound having a π-electron aromatic ring and carbon black are physically or chemically bonded. Must be present at least on the surface.

The method for producing the composite of the present invention includes, for example, (1) surface-treating carbon black with a solution containing a compound having a π-electron aromatic ring and an inorganic acid and / or an organic acid, and then further adding an oxidizing agent. (2) After surface-treating carbon black with a solution containing a compound having a π-electron aromatic ring and an inorganic acid and / or an organic acid, an oxidizing agent and an inorganic acid and / or (3) surface treatment with a solution containing an organic acid, (3) surface treatment of a slurry of carbon black with a solution containing a compound having a π-electron aromatic ring and an inorganic acid and / or an organic acid and an oxidizing agent, 4) After the carbon black is surface-treated with a solution containing an inorganic acid and / or an organic acid and an oxidizing agent, the surface is further treated with a solution containing a compound having a π-electron aromatic ring and an inorganic acid and / or an organic acid. (5) a method in which carbon black is subjected to a surface treatment with a solution containing an inorganic acid and / or an organic acid and an oxidizing agent, and further subjected to a surface treatment in a gas phase atmosphere of a compound having a π-electron aromatic ring; A) a method of surface-treating carbon black with a solution containing an oxidized condensate;
(7) A method of dispersing and mixing carbon black and an oxidative condensate is exemplified.

The inorganic acid and / or organic acid used in the present invention may be any one, and specifically, sulfuric acid,
Protonic acids such as hydrochloric acid, nitric acid, perchloric acid and borofluoric acid and salts thereof; carboxylic acids such as acetic acid, formic acid and benzoic acid and salts thereof; phenols such as phenol, nitrophenol, cyanophenol and the like Salts: benzenesulfonic acid, p-toluenesulfonic acid, p
-Dodecylbenzene sulfonic acid, alkyl naphthalene sulfonic acid, anthraquinone sulfonic acid, alkyl sulfonic acid, dodecyl sulfonic acid, camphor sulfonic acid, dioctyl sulfosuccinic acid, copper phthalocyanine tetrasulfonic acid, porphyrin tetrasulfonic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, Organic sulfonic acids such as naphthalene sulfonic acid condensate and salts thereof; phosphates such as propyl phosphate, butyl phosphate, hexyl phosphate, polyethylene oxide dodecyl ether phosphate, polyethylene oxide alkyl ether phosphate, and the like; Sulfates such as lauryl sulfate, cetyl sulfate, stearyl sulfate, lauryl ether sulfate, and the like; These salts and the like. Preferably, hydrochloric acid, sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid, p-dodecylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, alkylsulfonic acid, dodecylsulfonic acid, camphorsulfonic acid, dioctylsulfosuccinic acid, polystyrenesulfonic acid, Organic sulfonic acids such as polyvinyl sulfonic acid and naphthalene sulfonic acid condensate, and salts thereof. These inorganic acids and / or
Alternatively, the organic acids may be used alone or in combination of two or more. The addition amount of the inorganic acid and / or the organic acid is 0.001 to 15 in a molar ratio to the compound having a π-electron aromatic ring, and further,
It is preferably 0.005 to 10.

The solvent used for producing the complex of the present invention is not particularly limited, but is particularly preferably a solvent which can oxidatively condense the compound having a π-electron aromatic ring. Specifically, water, alcohols such as methanol, ethanol and propanol, ketones such as acetone and methyl ethyl ketone, nitriles such as acetonitrile and benzonitrile, N, N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone,
Solvents such as propylene carbonate can be mentioned. Preferred is water or a solvent containing water.

The reaction temperature of the oxidative condensation reaction is not particularly limited, but is preferably -20 to 400 ° C. and 300 ° C. or lower.
This is because even if the polymerization temperature is higher than 400 ° C., it is difficult to obtain a further improvement effect.

The composite of the present invention containing an inorganic acid and / or an organic acid produced by the above-mentioned production method may be directly blended into a rubber, but the inorganic acid and / or organic acid may be compounded from the composite of the present invention. The removed material may be compounded in the rubber. The method for removing the inorganic acid and / or the organic acid from the composite of the present invention is not particularly limited, and any known method can be used. In general, the complex of the present invention containing an inorganic acid and / or an organic acid may be brought into contact with a basic compound. It may be operated in a state. Examples of the basic compound include primary, secondary and tertiary alkylamines (eg, mono, di, triethylamine), hydrazine and derivatives thereof, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium carbonate, Examples thereof include alkali metal carbonates such as potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate, and ammonia.

The obtained composite of the present invention may be dried at room temperature or under heating. The drying temperature is 10
~ 350 ° C, preferably 25-300 ° C.

When a π-conjugated polymer compound is used in the composite of the present invention, for example, (1) a monomer forming a π-conjugated polymer compound and a doping agent are contained, and carbon black is dispersed. A method of adding an oxidizing agent to a solution, (2) a method of adding a monomer forming an π-conjugated polymer compound to a solution containing an oxidizing agent and a doping agent and dispersing carbon black, (3)
A method of adding an oxidizing agent and a doping agent to a solution containing a monomer forming a π-conjugated polymer compound and dispersing carbon black, (4) a monomer forming a π-conjugated polymer compound, a doping agent, and an oxidizing agent. A method of adding carbon black to a solution containing an agent, (5) forming a π-conjugated polymer compound in a solution containing a monomer forming a π-conjugated polymer compound, a doping agent, and an oxidizing agent; A method of surface-treating carbon black with a solution containing a conjugated polymer may be used.

The monomer forming the π-conjugated polymer compound is a compound having a π-electron aromatic ring in the molecular structure. Examples of such a monomer include aniline, naphthylamine, phenylenediamine, naphthylenediamine, triaminobenzene, triaminonaphthalene, pyrrole, thiophene, furan, benzene, and derivatives thereof. Examples of the derivative include compounds in which one or more substituents such as an alkyl group having 1 to 30 carbon atoms, an alkoxy group, an alkylene oxide group, a sulfonic acid group, and an alkylene sulfonic acid group are introduced on an aromatic ring. The above monomers may be used alone or in combination of two or more.

The oxidizing agent used in the present invention is not particularly limited as long as it has polymerization activity with respect to the above-mentioned monomers, and examples thereof include the above-mentioned ones. The amount of the oxidizing agent to be added is preferably 0.005 to 20, more preferably 0.01 to 10, as a molar ratio to the monomer (oxidizing agent / monomer).

The doping agent added when forming the composite of the present invention is not particularly limited, and any doping agent capable of doping the π-conjugated polymer compound can be used. Can be used. Specific examples include iodine, bromine, chlorine, halogen compounds such as iodine,
Protic acids such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, borofluoric acid, etc., various salts of these protonic acids, aluminum trichloride, iron trichloride, molybdenum chloride, antimony chloride, arsenic pentafluoride, antimony pentafluoride, etc. Lewis acid, acetic acid,
Organic acids such as trifluoroacetic acid, benzenesulfonic acid and p-toluenesulfonic acid, and high molecular acids such as polyethylenesulfonic acid, polyethylenecarboxylic acid, polyacrylic acid and polystyrenesulfonic acid.

Among the doping agents, particularly preferred are protonic acids such as sulfuric acid, hydrochloric acid, nitric acid, perchloric acid and borofluoric acid, various salts of these protonic acids, and carboxylic acids such as acetic acid, formic acid and benzoic acid. And salts thereof, phenols such as phenol, nitrophenol and cyanophenol, and salts thereof, benzenesulfonic acid, p-toluenesulfonic acid, p-dodecylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, anthraquinonesulfonic acid, and alkylsulfonic acid. Organic sulfonic acids such as dodecyl sulfonic acid, camphor sulfonic acid, dioctyl sulfosuccinic acid, copper phthalocyanine tetrasulfonic acid, porphyrin tetrasulfonic acid, polystyrene sulfonic acid, polyvinyl sulfonic acid, naphthalene sulfonic acid condensate and salts thereof Phosphates such as propyl phosphate, butyl phosphate, hexyl phosphate, polyethylene oxide dodecyl ether phosphate, polyethylene oxide alkyl ether phosphate and salts thereof, lauryl sulfate, cetyl sulfate, stearyl sulfate And sulfuric esters such as lauryl ether sulfate and salts thereof. Preferably, hydrochloric acid, nitric acid, benzenesulfonic acid, p-toluenesulfonic acid, p-dodecylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, alkylsulfonic acid, dodecylsulfonic acid, camphorsulfonic acid, dioctylsulfosuccinic acid, polystyrenesulfonic acid, Organic sulfonic acids such as polyvinyl sulfonic acid and naphthalene sulfonic acid condensate, and salts thereof.

These doping agents may be used alone or in combination of two or more. The addition amount of the doping agent is 0.0 as a molar ratio to the monomer (dopant / monomer).
It is preferably from 01 to 15, more preferably from 0.005 to 10.

The solvent used for producing the complex of the present invention is not particularly limited as long as it is a solvent capable of oxidatively polymerizing the above-mentioned monomers, and specific examples thereof include water, methanol, ethanol, propanol and the like. Alcohols, ketones such as acetone and methyl ethyl ketone, nitriles such as acetonitrile and benzonitrile, N, N-
Dimethylformamide, dimethylsulfoxide, N-
Solvents such as methylpyrrolidone and propylene carbonate can be mentioned. Preferred is water or a solvent containing water.

The polymerization temperature in the reaction is not particularly limited, but is preferably -20 to 90 ° C, more preferably 70 ° C or lower. If the polymerization temperature exceeds 90 ° C, side reactions tend to occur,
This is because it becomes difficult to form a π-conjugated polymer compound having the intended structure.

The composite of the present invention containing the doping agent produced by the above-mentioned production method may be directly blended with rubber. However, the composite of the present invention is subjected to de-doping treatment to remove the doping agent and to remove the doping agent. May be blended. The method for dedoping the composite of the present invention is not particularly limited, and any known method can be used. Generally, the complex of the present invention containing a doping agent may be brought into contact with a basic compound, and the basic compound may act on the formed complex of the present invention in a gas phase or a liquid phase. Is also good. Examples of the basic compound include primary, secondary and tertiary alkylamines (for example, mono, di, triethylamine), hydrazine and derivatives thereof, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium carbonate, and carbonate. Examples thereof include alkali metal carbonates such as potassium, sodium hydrogen carbonate, and potassium hydrogen carbonate, and ammonia.

The composite of the present invention produced without adding a doping agent may be compounded in rubber.

The obtained composite of the present invention may be dried at room temperature or under heating. The drying temperature is 25
It is preferably from 350 to 350 ° C, more preferably from 60 to 300 ° C.

The rubber raw material used in the present invention is at least one selected from natural rubber and diene-based synthetic rubber. That is, from natural rubber and many diene-based synthetic rubbers, these may be used alone or as a blend of two or more thereof. As the diene-based synthetic rubber, for example, polyisoprene rubber, polybutadiene rubber,
Styrene butadiene rubber, butyl rubber, chlorobutyl rubber, chloroprene rubber and the like can be mentioned. These rubbers are merely examples, and the present invention is not limited to the above rubbers.

The amount of the composite of the present invention is 10 to 180 parts by weight, preferably 30 to 160 parts by weight, per 100 parts by weight of rubber.
Parts by weight. In addition, the composite of the present invention can be used in combination with a filler usually compounded in rubber. Suitable fillers include silica. When silica is used in combination, the amount of silica is preferably 0 to 120 parts by weight, more preferably 0 to 80 parts by weight, based on 100 parts by weight of the rubber. The weight ratio of silica to the composite of the present invention (silica: composite) is preferably 1:20 to 20: 1.
The total amount of silica and the composite of the present invention is preferably 10 to 180 parts by weight, more preferably 25 to 150 parts by weight, based on 100 parts by weight of rubber.

When silica is used in combination, it is preferable to use 3 to 20 parts by weight of the silane coupling agent with respect to 100 parts by weight of the silica. Suitable silane coupling agents include bis (3-triethoxysilylpropyl) tetrasulfide (Si69), bis (3-triethoxysilylpropyl) disulfide (Si75) and the like.

The rubber composition of the present invention comprises a vulcanizing agent, a vulcanization accelerator, a vulcanization retarder, a curing aid such as an activator and an antioxidant,
Additives commonly used as rubber auxiliaries, such as softeners, plasticizers and antioxidants, can be appropriately compounded with the composite of the present invention.

Vulcanizing agents include sulfur or sulfur donating vulcanizing agents such as amine disulfides, polymeric polysulfides or sulfur / olefin adducts. Sulfur is preferred as the sulfur vulcanizing agent. Further, peroxides may be used as the vulcanizing agent. The amount of sulfur-based vulcanizing agent added is
0.1 to 30 parts by weight, or 0.5 to 100 parts by weight of rubber
It is preferably from 10 to 10 parts by weight, more preferably from 1 to 6 parts by weight. The amount of peroxides is based on 100 parts by weight of rubber.
It is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight.

Examples of the vulcanization accelerator include thiazoles such as dibenzothiazyl disulfide, Nt-butyl-2-benzothiazolylsulfenamide and N-cyclohexyl-2-benzothiazolylsulfenamide. And dithiocarbamic acids, guanidines, thioureas, xanthogenic acids and the like, as well as agents and thiurams vulcanization accelerators such as tetramethylthiuram disulfide. The vulcanization accelerator is preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the rubber.

The other rubber auxiliaries are used in an appropriate amount applied to the intended use. An appropriate amount is, for example, 0.1 to 50 parts by weight based on 100 parts by weight of rubber.

The mixing of the rubber, the composite of the present invention with other compounding agents and rubber auxiliaries can be carried out by a conventional mixing method, for example, using a mixer such as a roll, an internal mixer, and a Banbury mixer.

The rubber composition according to the present invention is applicable not only to rubber compositions for tires such as rubber compositions for tire treads, but also to other rubber products.

[0042]

EXAMPLES The present invention will be further described with reference to the following examples, but it goes without saying that the scope of the present invention is not limited to these examples. Complex carbon black (complex 1 to 11) and comparative of the present invention manufactured by the manufacturing method illustrated in following examples 1 to 22 and Comparative Examples 1~2 (N339, N ₂ S
A = 92 m ² / g) at a compounding ratio (parts by weight) shown in Tables 1 and 2 below to produce a rubber composition.
Vulcanize the rubber under the conditions of 20 minutes, for these unvulcanized rubber composition and vulcanized rubber composition, subjected to the following tests,
The results are shown in Tables 1 and 2. Composite 1 (anilinated condensate / carbon black composite
Aniline production water 80g body) 5g (53.7mmol), hydrochloride 5.6 g (53.7
mmol) and 40 mg of iron (II) sulfate. After a surface treatment of 100 g of carbon black (N339) was performed with the aqueous aniline solution, a surface treatment of carbon black was further performed with 20 g of water in which 5.2 g (53.7 mmol) of aqueous hydrogen peroxide was dissolved. The surface-treated carbon black was dried at 110 ° C. for 24 hours to obtain a composite comprising an aniphosphorylation condensate and carbon black. Composite 2 (anilinated condensate / carbon black composite
Aniline production water 80g body) 5g (53.7mmol), hydrochloride 5.6 g (53.7
mmol), 5.1 g (26.8 mmol) of p-toluenesulfonic acid and 40 mg of iron (II) sulfate. After a surface treatment of 100 g of carbon black (N339) was performed with the aqueous aniline solution, a surface treatment of carbon black was further performed with 20 g of water in which 5.2 g (53.7 mmol) of aqueous hydrogen peroxide was dissolved. The surface-treated carbon black was dried at 110 ° C. for 24 hours to obtain a composite comprising an aniphosphorylation condensate and carbon black. Composite 3 (anilinated condensate / carbon black composite
Aniline production water 80g body) 5g (53.7mmol), hydrochloride 5.6 g (53.7
mmol), 7.8 g of sodium dodecyl sulfonate (26.8 mm
ol) and 40 mg of iron (II) sulfate. After a surface treatment of 100 g of carbon black (N339) was performed with the aqueous aniline solution, a surface treatment of carbon black was further performed with 20 g of water in which 5.2 g (53.7 mmol) of aqueous hydrogen peroxide was dissolved.
The surface-treated carbon black was dried at 110 ° C. for 24 hours to obtain a composite comprising an aniphosphorylation condensate and carbon black. Composite 4 (anilinated condensate / carbon black composite
Aniline production water 100g body) 5g (53.7mmol), hydrochloride 5.6 g (5
3.7 mmol), 5.1 g of p-toluenesulfonic acid (26.8 mmol)
l) and 40 mg of iron (II) sulfate were dissolved at 70 ° C. After adding 5.2 g (53.7 mmol) of aqueous hydrogen peroxide to this aqueous aniline solution, the mixture was stirred at 70 ° C. for 4 hours to obtain an aqueous solution in which an aniphosphorylation condensate was uniformly dispersed. The aqueous solution containing this aniphosphorylation condensate contains carbon black (N3
39) After 100 g of surface treatment, it was dried at 110 ° C. for 24 hours. By the above operation, a composite comprising the aniphosphorylation condensate and carbon black was obtained. Composite 5 (anilinated condensate / carbon black composite
Aniline production water 100g body) 5g (53.7mmol), hydrochloride 5.6 g (5
3.7 mmol), 7.8 g of sodium dodecylsulfonate (26.
8 mmol) and 40 mg of iron (II) sulfate were dissolved at 70 ° C. After adding 5.2 g (53.7 mmol) of aqueous hydrogen peroxide to this aqueous aniline solution, the mixture was stirred at 70 ° C. for 4 hours to obtain an aqueous solution in which an aniphosphorylation condensate was uniformly dispersed. 100 g of carbon black (N339) was subjected to a surface treatment with the aqueous solution containing the aniphosphorylation condensate, and then dried at 110 ° C. for 24 hours. By the above operation, a composite comprising the aniphosphorylation condensate and carbon black was obtained. Composite 6 (anilinated condensate / carbon black composite
Body) manufacturing aniline black 5 g (Tokyo colorant Industry Co., Ltd., after the surface treatment of carbon black (N339) 100 g aniline black uniform aqueous dispersion consisting No25 aniline black) and water 100 g, 24 at 110 ° C. Dried for hours. By the above operation, a composite comprising aniline black (anilinated condensate) and carbon black was obtained. Complex 7 (anilinated condensate (polyaniline) / car
Preparation of Bon Black Composite ) 100 g of a polyaniline aqueous solution (5 wt% sulfonated polyaniline aqueous solution, manufactured by Aldrichs ) is used to prepare carbon black (N3
39) After 100 g of surface treatment, it was dried at 110 ° C. for 24 hours. By the above operation, a composite comprising an aniphosphorylation condensate (polyaniline) and carbon black was obtained. Composite 8 (pyrrole oxidized condensate / carbon black composite
As water 80g pyrrole 5g of the body) (74.5 mmol), sodium dodecyl sulfonate 6.5 g (22.5 mmol) and iron sulfate (II) 40 mg
Was dissolved. After a surface treatment of 100 g of carbon black (N339) was performed with this aqueous pyrrole solution, a surface treatment of carbon black was further performed with 20 g of water in which 7.2 g (74.5 mmol) of aqueous hydrogen peroxide was dissolved. The surface-treated carbon black was dried at 110 ° C. for 24 hours to obtain a composite comprising a pyrrole oxidized condensate and carbon black. Composite 9 (pyrrole oxidized condensate / carbon black composite
Preparation of pyrrole 5 g (74.5 mmol), sodium dodecylsulfonate 6.5 g (22.5 mmol) and iron (II) sulfate 40 in 100 g of water
mg was dissolved at 70 ° C. After 7.2 g (74.5 mmol) of aqueous hydrogen peroxide was added to the aqueous aniline solution, the mixture was stirred at 70 ° C. for 4 hours to obtain an aqueous solution in which pyrrole oxidative condensate was uniformly dispersed. 100 g of carbon black (N339) was subjected to a surface treatment with the aqueous solution containing the oxidized condensate of pyrrole, and then dried at 110 ° C. for 24 hours. By the above operation, a composite comprising a pyrrole oxidized condensate and carbon black was obtained. Composite 10 (thiophene oxidation condensate / carbon black composite
As water 80g thiophene 5g of polymer) (59.4 mmol), sodium dodecyl sulfonate 5.1 g (17.7 mmol), iron sulfate (II) 40 mg
Was dissolved. After 100 g of carbon black (N339) was surface-treated with this thiophene aqueous solution, the surface treatment of carbon black was further carried out with 20 g of water in which 5.8 g (59.4 mmol) of aqueous hydrogen peroxide was dissolved. The surface-treated carbon black was dried at 110 ° C. for 24 hours to obtain a composite comprising a thiophene oxidized condensate and carbon black. Composite 11 (thiophene oxidation condensate / carbon black composite
As water 100g thiophene 5g of polymer) (53.7 mmol), sodium dodecyl sulfonate 5.1 g (17.7 mmol) and iron (II) sulfate
40 mg was dissolved at 70 ° C. After 5.8 g (59.4 mmol) of aqueous hydrogen peroxide was added to the thiophene aqueous solution, the mixture was stirred at 70 ° C. for 4 hours to obtain an aqueous solution in which the thiophene oxidized condensate was uniformly dispersed. 100 g of carbon black (N339) was subjected to a surface treatment with the aqueous solution containing the thiophene oxidized condensate, and then dried at 110 ° C. for 24 hours. By the above operation, a composite comprising a thiophene oxidized condensate and carbon black was obtained. Mooney viscosity Measured at 100 ° C based on JIS K6300. The smaller the value, the better the workability and the better. Scorch time Measured at 125 ° C based on JIS K6300. Vulcanization time Based on JIS K6300, the time (min) to reach 95% vulcanization degree at 125 ° C was measured and defined as vulcanization time. The shorter the vulcanization time, the faster the vulcanization rate. Tensile properties According to JIS K 6251, 100% modulus (MPa), 3
The 00% modulus (MPa), the breaking strength (MPa) and the breaking elongation (%) were measured. tanδ Using a viscoelastic spectrometer manufactured by Toyo Seiki Seisaku-sho, the viscoelastic properties at 0 ° C. and 60 ° C. were measured under the conditions of an initial strain of 10%, an amplitude of ± 2%, and a frequency of 20 Hz. The wear resistance was measured using a Lambourn abrasion tester (Iwamoto Seisakusho Co., Ltd.) under the conditions of a load of 5 kg, a slip ratio of 25%, a time of 4 minutes and room temperature. In Table 2, Comparative Example 2 is shown as an index, each of which is 100. The larger the number, the better the wear resistance.

[0043]

[Table 1]

[0044]

[Table 2]

The components shown in Tables 1 and 2 were as follows. SBR1: Solution-polymerized SBR, Nipol 1712, manufactured by Zeon Corporation, oil exhibition containing 37.5 parts by weight of aroma oil per 100 parts by weight of rubber SBR2: Solution-polymerized SBR, Nipol 1712, manufactured by Zeon Corporation Carbon black: Carbon black N339, Tokai Nitrogen specific surface area (N ₂ SA) = 92 m ² / g, manufactured by Carbon Co., Ltd. Antioxidant: (N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine), manufactured by Bayer Co., Ltd. Agent: N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Toyo Kagaku Co., Ltd. From the above Tables 1 and 2, the rubber compositions of Examples 1 to 22 containing Complexes 1 to 11 of the present invention were compared with Comparative Example 1 Tanδ as compared with the rubber composition containing carbon black shown in
(0 ° C) while maintaining or increasing tanδ (60
° C) is reduced, and low rolling resistance is improved without lowering wet skid resistance. On the other hand, with regard to workability (Mooney viscosity, scorch time), tensile properties and abrasion resistance, composites 1-11
In the rubber compositions of Examples 1 to 22 containing the same, the characteristics of the rubber compositions mixed with the carbon black shown in Comparative Examples 1 and 2 are maintained as they are, and a decrease in mechanical properties is suppressed.

Further, the composites 1 to 11 were not complicated as in the above-mentioned conventional compounding agent and the production method was complicated, and could be easily produced.

As described above, according to the present invention, a compound consisting of an oxidized condensate obtained by oxidatively condensing a compound having a π-electron aromatic ring and a carbon black is mixed with a rubber composition, whereby a compounding agent which can be easily produced is prepared. Thereby, good wet skid resistance and low rolling resistance can be obtained. Examples 23 to 30 and Comparative Example 3 Composites (composites 12 to 19) comprising a π-conjugated polymer compound and carbon black produced by the production methods described below,
After preparing a rubber composition in which carbon black was mixed at a compounding ratio (parts by weight) shown in Table 3 below for comparison, 1
The rubber was vulcanized at 60 ° C. for 20 minutes and subjected to the following tests. The results are shown in Table 3. Of composite 12 (polyaniline / carbon black composite)
In 500 mL of production water, 2 g (21.5 mmol) of aniline and 2.24 g of hydrochloric acid (2
1.5 mmol) and 7.01 g of dodecylbenzenesulfonic acid (21.
5 mmol) was added. 100 g of carbon black (N220) was further added to the obtained aqueous solution with good stirring.
After cooling the solution to 5 ° C, ammonium persulfate
5.89 g (25.8 mmol) was added, and the mixture was stirred for 5 hours so that the reaction temperature did not exceed 10 ° C. After completion of the reaction, the black powder in the reaction solution was filtered and washed with water and methanol. In the filtrate and the washing solution when filtering the complex comprising polyaniline and carbon black from the reaction solution, green coloring derived from polyaniline was not observed. It was found that a complex was quantitatively formed with carbon black. Then, the obtained composite is dried at 80 ° C. for 8 hours,
A composite comprising doped polyaniline and carbon black was obtained. The amount of polyaniline in the composite was 2% by weight. Of composite 13 (polyaniline / carbon black composite)
In 500 mL of production water, 2 g (21.5 mmol) of aniline and 2.24 g of hydrochloric acid (2
1.5 mmol) and 7.01 g of dodecylbenzenesulfonic acid (21.
5 mmol) was added. 100 g of carbon black (N220) was further added to the obtained aqueous solution with good stirring.
After cooling the solution to 5 ° C, ammonium persulfate
5.89 g (25.8 mmol) were added. Stirring was performed for 5 hours so that the reaction temperature did not exceed 10 ° C. After completion of the reaction, sodium carbonate powder was added until the reaction solution showed basicity with pH test paper, and the mixture was stirred for 4 hours. The black powder in the reaction solution was filtered and washed with water and methanol. The filtrate and the washing solution when the complex comprising polyaniline and carbon black were filtered out from the reaction solution did not show blue coloring derived from the undoped polyaniline. It was found that the doped polyaniline quantitatively formed a complex with carbon black. Then, the obtained composite was dried at 80 ° C. for 8 hours to obtain a composite comprising undoped polyaniline and carbon black. The amount of polyaniline in the composite was 2% by weight. Of composite 14 (polyaniline / carbon black composite)
The amounts of aniline, hydrochloric acid, dodecylbenzenesulfonic acid and ammonium persulfate used for the production of the production complex 12 were 5 g (53.7 mmol), 5.6 g (53.7 mmol), and 17.5 g (53.7 mmol), respectively.
mmol) and 14.7 g (64.4 mmol) except for the complex
A composite comprising polyaniline and carbon black was obtained in the same manner as in Example 12. In the filtrate and the washing solution when the composite comprising polyaniline and carbon black is filtered out of the reaction solution, green coloring derived from the undoped polyaniline is not observed, and the doped polyaniline is quantitatively detected. It was found that a complex was formed with carbon black. Then, the obtained composite was dried at 80 ° C. for 8 hours to obtain a composite comprising undoped polyaniline and carbon black. The amount of polyaniline in the composite was 5% by weight. Of composite 15 (polyaniline / carbon black composite)
The amounts of aniline, hydrochloric acid, dodecylbenzenesulfonic acid and ammonium persulfate used in the production of the production complex 13 were 5 g (53.7 mmol), 5.6 g (53.7 mmol), and 17.5 g (53.7 mmol), respectively.
mmol) and 14.7 g (64.4 mmol), to obtain a composite composed of polyaniline and carbon black in the same manner as in the case of composite 13. The filtrate and the washing solution when the complex comprising polyaniline and carbon black were filtered out from the reaction solution did not show blue coloring derived from the undoped polyaniline. It was found that the doped polyaniline quantitatively formed a complex with carbon black. Then, the obtained composite was dried at 80 ° C. for 8 hours to obtain a composite comprising undoped polyaniline and carbon black. The amount of polyaniline in the composite was 5% by weight. Of composite 16 (polyaniline / carbon black composite)
Aniline 2g in manufacturing water 200 mL (21.5 mmol), hydrochloric acid 2.24 g (2
1.5 mmol) and 6.19 g of sodium dodecylsulfonate (2
After 1.5 mmol) was added and stirred well, the aqueous solution was cooled to 5 ° C. or lower. While maintaining the reaction solution at 5 ° C. or lower, 4.90 g (21.5 mmol) of ammonium persulfate was added with stirring to obtain a solution.
A time reaction was performed. As the reaction proceeded, a homogeneous green solution was obtained. This uniform polyaniline aqueous solution was added to 100 g of carbon black (N220) with good stirring.
When a part of the obtained composite composed of polyaniline and carbon black was collected and washed with water and methanol, green coloring derived from polyaniline was not observed. It was found that a complex was quantitatively formed with carbon black. Then, the remaining composite composed of polyaniline and carbon black was dried at 80 ° C. for 8 hours to obtain a composite composed of doped polyaniline and carbon black. The amount of polyaniline in the composite was 2% by weight. Of composite 17 (polyaniline / carbon black composite)
The amounts of water, aniline, hydrochloric acid, sodium dodecylsulfonate and ammonium persulfate used in the production of production complex 16 were
Each 500mL, 5g (53.7mmol) 5.6g (53.7mmo
l) A composite consisting of polyaniline and carbon black was obtained in the same manner as for composite 16, except that the amounts were changed to 15.5 g (53.7 mmol) and 12.3 g (53.7 mmol). When a part of the obtained composite composed of polyaniline and carbon black was collected and washed with water and methanol, no green color derived from polyaniline was observed in the washing solution, and the reaction was completed. It was found that the doped polyaniline quantitatively formed a complex with carbon black. Then, the remaining composite was dried at 80 ° C. for 8 hours to obtain a composite composed of doped polyaniline and carbon black. The amount of polyaniline in the composite was 5% by weight. Of composite 18 (polypyrrole / carbon black composite)
To 500 mL of production water, 2 g (29.8 mmol) of pyrrole and 9.73 g (29.8 mmol) of dodecylbenzenesulfonic acid were added. 100 g of carbon black (N220) was further added to the obtained aqueous solution while stirring well. After cooling this solution to 5 ° C., 8.16 g (35.8 mmol) of ammonium persulfate was added,
Stirring was performed for 5 hours so that the reaction temperature did not exceed 10 ° C. After completion of the reaction, the black powder in the reaction solution was filtered and washed with water and methanol. The filtrate and the washing liquid when filtering the complex consisting of polypyrrole and carbon black from the reaction solution did not show green-brown coloring derived from polypyrrole. Was quantitatively formed into a complex with carbon black. Then, the obtained composite was dried at 80 ° C. for 8 hours to obtain a composite composed of doped polypyrrole and carbon black. The amount of polypyrrole in the composite was 2% by weight. Of composite 19 (polypyrrole / carbon black composite)
To 500 mL of production water, 2 g (29.8 mmol) of pyrrole and 9.73 g (29.8 mmol) of dodecylbenzenesulfonic acid were added. 100 g of carbon black (N220) was further added to the obtained aqueous solution while stirring well. After cooling this solution to 5 ° C., 8.16 g (35.8 mmol) of ammonium persulfate was added,
Stirring was performed for 5 hours so that the reaction temperature did not exceed 10 ° C. After completion of the reaction, sodium carbonate powder was added until the reaction solution showed basicity with pH test paper, and the mixture was stirred for 4 hours.
The black powder in the reaction solution was filtered and washed with water and methanol. The filtrate and washing solution used when filtering the complex comprising polypyrrole and carbon black from the reaction solution did not show brown coloring derived from undoped polypyrrole. It was found that the doped polypyrrole quantitatively formed a complex with carbon black. Then, the obtained composite was dried at 80 ° C. for 8 hours to obtain a composite comprising undoped polypyrrole and carbon black. The amount of polypyrrole in the composite was 2% by weight.

The Mooney viscosity, scorch time, vulcanization time, tensile properties and tan δ were measured by the same methods as described above.

The wear resistance was measured using a Lambourn abrasion tester (manufactured by Iwamoto Seisakusho KK) with a load of 5 kg and a slip ratio of 25.
%, Time of 4 minutes, and room temperature were shown as indices with the value of Comparative Example 3 taken as 100. The larger the number, the better the wear resistance.

[0050]

[Table 3]

The following components were used in Table 3. SBR3: solution polymerization SBR, Nipol 1712, manufactured by Zeon Corporation Carbon black: carbon black N220, manufactured by Tokai Carbon Co., Ltd., nitrogen specific surface area (N ₂ SA) = 115 m ² / g Antioxidant: (N-phenyl-N′-) (1,3-dimethylbutyl) -p-phenylenediamine), Bayer vulcanization accelerator: N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Toyo Kagaku Company Examples 23 to 30 including a composite consisting of carbon black and composites (composites 12 to 19)
In the rubber composition of Comparative Example 3, tan δ (60 ° C.) was reduced while maintaining or increasing tan δ (0 ° C.) as compared with the rubber composition containing carbon black shown in Comparative Example 3. It can be seen that the low rolling resistance was improved without reducing the wet skid resistance. On the other hand, with regard to processability (Mooney viscosity, scorch time), tensile properties, and abrasion resistance, the rubber compositions of Examples 23 to 30 including composites 12 to 19 were blended with carbon black shown in Comparative Example 3. The properties of the rubber composition are maintained as they are, and a decrease in mechanical properties is suppressed.

Further, the composites 12 to 19 could be easily produced without a complicated production method in which the production steps were performed in multiple stages as in the conventional compounding agents described above.

[0053]

As described above, according to the present invention, the rubber composition is compounded with a composite comprising an oxidized condensate of a compound having a π-electron aromatic ring and carbon black.
Good wet skid resistance and low rolling resistance can be obtained by a compounding agent that is easily manufactured.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C08L 101/00 C08L 101/00 (72) Inventor Miaki Kirino 2-1 Oiwake, Hiratsuka-shi, Kanagawa Prefecture Yokohama Rubber F-term in Hiratsuka Works (reference) 4J002 AC00W CE00X CM05X DA036 GN01

Claims (8)

[Claims] 1. A rubber composition comprising (i) 100 parts by weight of a rubber and (ii) 10 to 180 parts by weight of a composite comprising carbon black and an oxidized condensate obtained by oxidatively condensing a compound having a π-electron aromatic ring. object. 2. The method according to claim 1, wherein the concentration of the oxidized condensate in the composite is 0.01
The rubber composition according to claim 1, wherein the content is from 30 to 30% by weight. 3. The rubber composition according to claim 1, wherein the composite has a carbon black surface coated with the oxidized condensate. 4. The rubber composition according to claim 1, wherein the compound having a π-electron aromatic ring is at least one selected from aniline, thiophene, pyrrole, and derivatives thereof. 5. The rubber composition according to claim 1, wherein the oxidized condensate of the compound having a π-electron aromatic ring is a π-conjugated polymer compound. 6. The rubber composition according to claim 5, wherein the π-conjugated polymer compound is at least one selected from the group consisting of polyaniline, polypyrrole, polythiophene, and derivatives thereof. 7. The rubber composition according to claim 5, wherein the amount of the π-conjugated polymer compound bound in the composite comprising the π-conjugated polymer compound and carbon black is 0.01 to 30% by weight. 8. A pneumatic tire using the rubber composition according to claim 1 for a tire tread.