JP6001995B2 - Rubber composition and pneumatic tire using the same - Google Patents

Description

  The present invention relates to a rubber composition and a pneumatic tire using the same.

  Conventionally, in the automobile industry, there has been a demand for fuel efficiency reduction of automobiles, and there has been a demand for a rubber composition for a tread that can provide a tire with low rolling resistance, and in terms of safety, grip properties on a wet road surface, That is, a rubber composition for a tread that can provide a tire having high wet grip properties is required.

  The rolling resistance and wet grip properties of these tires are related to the hysteresis loss (tan δ) of the tread rubber. At 10 Hz, the smaller the tan δ near 60 ° C., the lower the rolling resistance and the larger tan δ near 0 ° C. Although the wet grip property is so high, it has been difficult to make both compatible (Patent Document 1).

  As a rubber composition for a tread used for such a pneumatic tire in the automobile field, Patent Document 2 discloses a block copolymer composed of a conjugated diene polymer block and an acrylic polymer block, a diene rubber component, and a silicon system. A rubber composition comprising an inorganic filler has been disclosed, which is intended to improve the dispersibility of the silicon-based inorganic filler in the rubber component by means of a block copolymer. It does not improve gender balance.

  Patent Document 3 discloses an acrylic block copolymer (A) comprising a methacrylic polymer block (a) and a (meth) acrylic polymer block (b), natural rubber, and a diene polymer rubber. And a rubber composition for a pneumatic tire containing at least one rubber component (B) selected from olefin polymer rubber. However, although the tan δ value at 0 ° C. has increased by about 10%, the tan δ value at 40 ° C. tends to deteriorate rather, and further improvement is desired regarding the balance between rolling resistance and wet grip properties. Yes.

On the other hand, tan δ is high near 0 ° C. and 30 ° C., and the dynamic elastic modulus (G ′) is low near −20 ° C., so that the dry performance, wet performance and on-ice performance of the studless tire can be improved. Mainly natural rubber and / or polyisoprene rubber and polybutadiene rubber for the purpose of providing a rubber composition and a studless tire using such a rubber composition in a tread and having excellent dry performance, wet performance and on-ice performance. 20 to 70 parts by mass of at least one filler (B) selected from the group consisting of carbon black and white filler with respect to 100 parts by mass of the rubber component (A) as a component, and a weight average molecular weight in terms of polystyrene of 2 × a 10 ³ to 50 × 10 ³ (meth) acrylate (co) polymer (C) rubber, characterized in that by blending a 3-30 parts by weight Compositions, studless tire characterized by using the rubber composition in a tread has been proposed (Patent Document 4). However, the rubber composition containing such a simple (meth) acrylate polymer has a problem that friction on ice does not particularly increase and wear resistance is lowered. Moreover, there is no description regarding rolling resistance, and in fact, the balance between rolling resistance and wet grip is insufficient, and there is room for improvement. Moreover, there is no description regarding running stability, and there is no suggestion about what kind of effect is produced.

  In addition, the (meth) acrylate polymer and / or (meth) acrylamide type having two or more functional groups capable of hydrogen bonding and / or hydrolysis condensation reaction with the white filler (A) with respect to the diene rubber. A rubber composition characterized in that the polymer (B) is added after being mixed in advance, and a pneumatic tire having a tread portion obtained by using the rubber composition has high friction on ice and excellent wear resistance. Has been proposed (Patent Document 5). However, in order to obtain these effects, it is necessary to add a large amount of the polymer (B), and there is a problem that the cost is inferior. Moreover, there is no description regarding rolling resistance, and in fact, the balance between rolling resistance and wet grip is insufficient, and there is room for improvement. Further, a (meth) acrylate polymer and / or a (meth) acrylamide polymer (B) having two or more functional groups capable of hydrogen bonding and / or hydrolysis condensation reaction and a white filler (A) are previously added. When mixed, the functional group in the polymer and the surface of the white filler are hydrogen-bonded or chemically bonded, and the viscosity of the composition is increased, so that there is a problem that much energy is required for kneading.

  Patent Document 6 discloses an admixture obtained by kneading a vinyl polymer having a group having a polymerizable carbon-carbon double bond at at least one molecular terminal with a thermoplastic resin or a thermosetting resin. It is disclosed that when cured, the mechanical properties, heat resistance, chemical resistance, and weather resistance of the thermoplastic resin or thermosetting resin can be improved. However, there is no description about applying such a vinyl polymer to a tire, and when a (meth) acrylic polymer having a reactive double bond at one end is added to a diene rubber. There is no suggestion about what effect the obtained cured product exerts on the balance of rolling resistance / wet grip and running stability.

JP 2004-196937 A JP 2003-89729 A JP 2010-254908 A JP 2006-274051 A JP2012-21149A JP 2008-255198 A

  The problem to be solved by the present invention is to provide a rubber composition having an excellent balance of conflicting properties such as rolling resistance and wet grip properties, and also excellent running stability.

  As a result of intensive studies to solve the above problems, by adding a (meth) acrylic polymer (D) having a double bond capable of reacting at the time of vulcanization of the diene rubber at the molecular piece end, The present inventors have found that a rubber composition having excellent balance of contradictory properties such as rolling resistance and wet grip property and excellent running stability can be obtained, and the present invention has been completed.

  That is, the present invention can react at 10 to 150 parts by weight of the white filler (B) and / or carbon black (C) with respect to 100 parts by weight of the diene rubber (A) and at the time of vulcanization of the diene rubber. The present invention relates to a rubber composition characterized by containing 0.5 to 20 parts by weight of a (meth) acrylic polymer (D) having a double bond at a molecular piece terminal.

  A preferred embodiment is characterized by containing 0 to 90 parts by weight of white filler (B) and / or 0 to 60 parts by weight of carbon black (C) with respect to 100 parts by weight of diene rubber (A). The present invention relates to a rubber composition.

  In a preferred embodiment, the diene rubber (A) is at least one selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber. .

  In a preferred embodiment, the white filler (B) is at least one selected from the group consisting of silica, clay, mica, talc, shirasu, calcium carbonate, magnesium carbonate, aluminum hydroxide and barium sulfate. The present invention relates to a characteristic rubber composition.

  In a preferred embodiment, the double bond capable of reacting with the diene rubber (A) is at least one selected from the group consisting of an alkenyl group and a (meth) acryloyl group. The present invention relates to a rubber composition.

  In a preferred embodiment, the (meth) acrylic polymer (D) has a number average molecular weight of 5,000 to 100,000.

  As a preferred embodiment, the (meth) acrylic polymer (D) has a carboxyl group, a hydroxyl group, an ether group, an amide group, an amino group, a hydrolyzable silyl group, an epoxy group, an acid anhydride group, in the molecular chain. The present invention relates to a rubber composition having at least one functional group selected from the group consisting of active chlorine groups in the molecule.

  As a preferred embodiment, the present invention relates to a rubber composition characterized in that the rubber composition is for tires.

  As a preferred embodiment, the present invention relates to a pneumatic tire using the rubber composition described above.

  As a preferred embodiment, the present invention relates to a pneumatic tire tread characterized by using the rubber composition described above.

  The rubber composition of the present invention is obtained by blending a rubber component conventionally used in tires with a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of a diene rubber at the molecular end. It can be used as a rubber composition and a pneumatic tire that are excellent in the balance of conflicting characteristics such as rolling resistance and wet grip properties and excellent in running stability.

  In the present invention, 10 to 150 parts by weight of white filler (B) and / or carbon black (C) can be reacted with 100 parts by weight of diene rubber (A) and at the time of vulcanization of diene rubber. It is a rubber composition characterized by containing 0.5 to 20 parts by weight of a (meth) acrylic polymer (D) having a heavy bond at the end of a molecular piece.

  Hereinafter, each component of the present invention will be described in detail.

<Diene rubber (A)>
The diene rubber (A) is not particularly limited as long as it is a rubber obtained from a monomer containing a diene compound. For example, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile butadiene rubber, ethylene-propylene-diene copolymer rubber, styrene-isoprene copolymer. Examples thereof include rubber, isoprene-butadiene copolymer rubber, styrene-isoprene-butadiene copolymer rubber and chloroprene rubber. The styrene-butadiene copolymer rubber (SBR) may be either an emulsion polymerization method SBR or a solution polymerization method SBR. It may be a rubber having a functional group introduced, such as solution polymerization SBR or modified butadiene rubber. The diene rubber (A) is more preferably natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, butadiene rubber, or a blend of two or more thereof.

  These diene rubbers may be used in combination with at least one selected from the group consisting of olefin polymer rubbers. Examples of the olefin rubber include butyl rubber, chlorinated butyl rubber, brominated butyl rubber, and ethylene-propylene-diene rubber.

<White filler (B)>
The white filler (B) is not particularly limited as long as it can generally be blended as a filler in a rubber composition. Examples of the white filler (B) include silica; clay minerals such as clay and talc and silicate minerals such as mica; shirasu; calcium carbonate (for example, colloidal calcium carbonate, ultrafine calcium carbonate, light calcium carbonate , Heavy calcium carbonate), carbonates such as magnesium carbonate and potassium carbonate; alumina hydrates such as aluminum hydroxide; and barium sulfate.

  Especially, it is selected from the group consisting of silica, clay, talc, mica and other silicate minerals, shirasu, calcium carbonate, magnesium carbonate, aluminum hydroxide, and barium sulfate because of its excellent balance of rolling resistance and wet grip. At least one kind is preferred, and silica having a higher effect is more preferred.

  Silica is not particularly limited, and examples thereof include wet silica, dry silica, and pulverized silica. Of these, wet silica is preferred because it is excellent in wear resistance, mechanical properties, and economy.

  The white filler (B) may be used alone or in combination of two or more.

  In the present invention, the amount of the white filler (B) is preferably 0 to 90 parts by weight with respect to 100 parts by weight of the diene rubber. The amount of the white filler (B) is more preferably 10 to 60 parts by weight with respect to 100 parts by weight of the diene rubber (A) in terms of excellent balance between rolling resistance and wet grip properties. More preferably, it is ˜60 parts by weight.

<Carbon black (C)>
Carbon black (C) is not particularly limited as long as it can generally be blended as a filler in a rubber composition. Examples of carbon black (C) include FEF, SRF, HAF, ISAF, and SAF grades. Carbon black (C) is preferably HAF, ISAF, or SAF grade in terms of further improving mechanical properties and wear resistance. Carbon black (C) may be used alone or in combination of two or more.

  In the present invention, the amount of carbon black (C) is preferably 0 to 60 parts by weight with respect to 100 parts by weight of the diene rubber. The amount of carbon black (C) is more preferably 5 to 60 parts by weight and more preferably 5 to 40 parts by weight with respect to 100 parts by weight of the diene rubber (A) in terms of superior wear resistance. Is more preferable.

  The total amount of the white filler (B) and the carbon black (C) is 10 to 150 parts by weight with respect to 100 parts by weight of the diene rubber (A) in terms of excellent mechanical properties and excellent wear resistance. However, it is preferably 30 to 90 parts by weight.

  When both the white filler (B) and the carbon black (C) are blended as fillers, the amount of the carbon black (C) is 10 to 50% by weight in the total amount of the filler in that it is more excellent in wear resistance. It is preferably 10 to 30% by weight in that rolling resistance is further improved.

<(Meth) acrylic polymer (D) having a double bond capable of reacting at the time of vulcanization of a diene rubber>
The rubber composition of the present invention comprises a (meth) acrylic polymer (D) having a double bond capable of reacting at the time of vulcanization of a diene rubber, at 100 parts by weight of the diene rubber (A). And 0.5 to 20 parts by weight. Preferably it is 0.5-10 weight part, More preferably, it is 0.5-5 weight part. If the added amount is less than 0.5 parts by weight, it becomes difficult to obtain an effect of improving the balance between rolling resistance and wet grip properties. If the added amount is more than 20 parts by weight, it is not only economically disadvantageous but also handling of the rubber composition is difficult. It becomes difficult and not preferable.

<< Double bond capable of reacting during vulcanization of diene rubber >>
The double bond capable of reacting during the vulcanization of the diene rubber is not particularly limited as long as it is a double bond functional group capable of reacting when the diene rubber is sulfur vulcanized or peroxide vulcanized. Examples of such a double bond include an alkenyl group, an alkenoxy group, an alkenoyl group, an alkynyl group, and a (meth) acryloyl group.

The alkenyl group, alkenoxy group, and alkenoyl group may be any of linear, branched, and cyclic groups having 2 to 22 carbon atoms, such as a vinyl group, vinyloxy group, propenyl group, propenoxy group, and butenyl group. , Butenoxy group, butenoyl group, pentenyl group, pentenoxy group, pentenoyl group, pentadienyl group, pentadienoxy group, pentadienoyl group, hexenyl group, hexenoxy group, hexenoyl group, hexadienyl group, hexadienoxy group, hexadienyl group, hexatrienyl group, hexatrienyl group Enoxy group, hexatrienoyl group, heptenyl group, heptenoxy group, heptenoyl group, heptadienyl group, heptadienoxy group, heptadienoyl group, heptatrienyl group, heptatrienoxy group, heptatrienoyl group, octet Group, octenoxy group, octenoyl group, octadienyl group, octadienoxy group, octadienoyl group, octatrienyl group, octatrienoxy group, octatrienoyl group, octatetraenyl group, octatetraenoxy group, octatetraenoyl group , Nonenyl group, noneneoxy group, nonennoyl group, nonadienyl group, nonadienoxy group, nonadienoyl group, nonatrienyl group, nonatrienoxy group, nonatrienoyl group, nonatetraenyl group, nonatetraenoxy group, nonatetraenoyl group, decenyl group, decenoyl group, decenoyl group And their dienes, trienes, tetraenes, pentaene compounds, undecenyl groups, undecenoxy groups, undecenoyl groups, and their dienes, trienes, tetraenes, pentaene compounds, Decenyl group, dodecenoxy group, dodecenoyl group, and their dienes, trienes, tetraenes, pentaenes, hexaene compounds, tridecenyl groups, tridecenoxy groups, tridecenoyl groups, and their dienes, trienes, tetraenes, pentaenes, hexaene compounds, tetradecenyl groups, tetradecenyl groups Groups, tetradecenoyl groups, and their dienes, trienes, tetraenes, pentaenes, hexaenes, heptaene compounds, pentadecenyl groups, pentadecenoxy groups, pentadecenoyl groups, and their dienes, trienes, tetraenes, pentaenes, hexaenes, heptaene compounds, hexadecenyl groups, hexadecenoxy Group, hexadecenoyl group, and these dienes, trienes, tetraenes, pentaenes, hexaenes, heptae , Octaene compounds, heptadecenyl groups, heptadecenoxy groups, heptadecenoyl groups, and these dienes, trienes, tetraenes, pentaenes, hexaenes, heptaenes, octaene compounds, and the like. In addition, oleyl group (—C ₁₈ H ₃₅ ), linoleyl group (—C ₁₈ H ₃₃ ), linolenyl group (—C ₁₈ H ₃₁ ), arachidonyl group (—C ₂₀ H ₃₅ ), eicosapentaenyl. group (C ₂₀ H _33), 11- docosenyl (-C ₂₂ H _43), 13- docosenyl (-C ₂₂ H _43), 12- hydroxy-9-octadecenyl, docosahexaenoyl-enyl (-C ₂₂ H ₃₃ ), oleyloxy group, linoleoxy group, linoleinoxy group, arachidoxy group, eicosapentaenoxy group, 11-docosenoxy group, 13-docosenoxy group, 12-hydroxy-9-octadecenoxy group, docosahexaenoxy group, Undecenoyl group, hexadecenoyl group, oleoyl group, linoleyl group, linoyl group, arachidonoyl group, 11-docosenoyl group, 13-docosenoyl group, 1 Examples thereof include functional groups derived from natural fatty acids such as 2-hydroxy-9-octadecenoyl group, docosahexaenoyl group, and eicosapentaenoyl group.

  Also, functional groups such as dicyclopentenyl group, dicyclopentenyloxyethyl group, 2-vinyloxyethyl group, 2- (2-vinyloxyethoxyethyl) group, terpenyl group, limonel group, orthostyryl group, metastyryl group, parastyryl group, etc. Also mentioned.

  Further, among these groups, an organic group in which a hydrogen atom is substituted with a halogen atom such as fluorine, chlorine, bromine, or iodine, or an organic group containing an oxygen atom or a nitrogen atom can be given.

  The alkynyl group may be any of linear, branched and cyclic alkynyl groups having 2 to 10 carbon atoms, such as ethynyl group, propynyl group, 1-butynyl group, 1-pentynyl group and 3-methyl. Examples thereof include a -1-butynyl group and a phenylbutynyl group.

  Examples of the (meth) acryloyl group include an acryloyl group, a methacryloyl group, an acryloxy group, and a methacryloxy group.

  The double bond capable of reacting during vulcanization of these diene rubbers is an alkenyl group or a (meth) acryloyl group from the viewpoint of excellent balance between rolling resistance and wet grip properties and good reactivity. Among them, from the viewpoint of easy introduction into the polymer, vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, octenyl group, undecenyl group, undecenoyl group, oleyl group, oleoyl group, acryloxy group A methacryloxy group is preferred.

<< Main chain of (meth) acrylic polymer >>
The (meth) acrylic monomer constituting the main chain of the (meth) acrylic polymer (D) having a double bond capable of reacting at the time of vulcanization of the diene rubber in the present invention is not particularly limited. Various types can be used.

  As (meth) acrylate monomers, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-n-propyl, isopropyl (meth) acrylate, (meth) acrylic N-butyl acid, isobutyl (meth) acrylate, (tert-butyl) (meth) acrylate, n-pentyl (meth) acrylate, isoamyl (meth) acrylate, (n) hexyl (meth) acrylate, ( (Meth) acrylic acid cyclohexyl, (meth) acrylic acid-n-heptyl, (meth) acrylic acid-n-octyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid isooctyl, (meth) acrylic acid nonyl, (Meth) acrylic acid isononyl, (meth) acrylic acid decyl, (meth) acrylic acid isodecyl, (meth) Undecyl crylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, (meth) acrylic Stearyl acid, isostearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate, 2-decyltetradecanyl (meth) acrylate, phenyl (meth) acrylate, toluyl (meth) acrylate , Tolyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (Meth) acrylic acid dicyclopentanyl Oxyethyl, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, adamantyl (meth) acrylate, 3-hydroxy-1- (meth) acrylate Adamantyl, 1-methyladamantyl (meth) acrylate, 1-ethyladamantyl (meth) acrylate, 3, (meth) acrylic acid, 5-dihydroxy-1-adamantyl, benzyl (meth) acrylate, (meth) acrylic acid 2 -Methoxyethyl, 2-butoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, (meth) acrylic acid Phenoxyethyl, methyl phenoxy (meth) acrylate , (Meth) acrylic acid m-phenoxybenzyl, (meth) acrylic acid ethyl carbitol, (meth) acrylic acid-methoxytriethylene glycol, (meth) acrylic acid-ethoxydiethylene glycol, (meth) acrylic acid 2-hydroxy-3 -Phenoxypropyl, (meth) acrylic acid 2-ethylhexyl diethylene glycol, (meth) acrylic acid methoxy-dipropylene glycol, (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,4-cyclohexanedimethanol (meth) acrylate, glycerin (meth) acrylate, (meth) Acrylic acid polyester Lenglycol (Nippon's Blemmer PE-90, PE-200, PE-350, PE-350G, AE-90, AE-200, AE-400, etc.), (meth) acrylic acid polypropylene glycol (Nippon's Blemmer PP -500, PP-800, PP-1000, AP-150, AP-400, AP-550, etc.) (meth) acrylic acid polyethylene glycol-polypropylene glycol (Nippon Bremer 50PEP-300, 70PEP-350B etc.), ( (Meth) acrylic acid polyethylene glycol-polypropylene glycol, (meth) acrylic acid polyethylene glycol-polytetramethylene glycol, (meth) acrylic acid polypropylene glycol-polytetramethylene glycol), (meth) acrylic acid polyethylene glycol -Polybutylene glycol, glycidyl (meth) acrylate, 4-hydroxybutyl-glycidyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, 2-aminoethyl (meth) acrylate, diethylamino (meth) acrylate Ethyl, dimethylaminoethyl quaternary (meth) acrylate (light ester DQ-100, DQ-75, etc. manufactured by Kyoeisha Chemical), 4- (meth) acrylic acid-2-methyl-2-ethyl-1,3-dioxolane 2- (meth) acrylic acid-1,4-dioxaspiro [4,5] dec-2-ylmethyl (manufactured by Osaka Organic Chemical Industry, CHDOL-10), 3-ethyl-3-oxetanyl (meth) acrylate (Osaka) OXE-10), (meth) acrylic acid γ-butyrolactone, (meth) acrylic acid 2 Phenylthioethyl, (meth) acrylic acid 2-hydroxy-3- (2-propenyloxy) propyl, phthalic anhydride- (meth) acrylic acid 2-hydroxypropyl adduct (Biscoat # 2100, manufactured by Osaka Organic Chemical Industry), 2 -(Meth) acryloyloxyethyl phthalic acid (Kyoeisha Chemical Light Ester HPA-MPL, Shin-Nakamura Chemical CB-1 etc.), 1,2-cyclohexyldicarboxylic acid-mono [1-methyl-2-[(1-oxo -2-propenyl) oxy] ethyl] ester (Biscoat # 2150 made by Osaka Organic Chemical Industry), (meth) acryloyloxy-ethylhexahydrophthalate (light ester HO-HH, HOA-HH, etc. made by Kyoeisha Chemical), (meta ) Acrylic Royloxyethyl Succinate (Kyoeisha Chemical Light Ester HO-M , HOA-MS, Shin-Nakamura Chemical SA, A-SA, etc.), 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalic acid (Kyoeisha Chemical Light Ester HO-MPP, etc.), 2- (meth) Acryloyloxyethyl-hydroxyethylphthalic acid (HOE-MPE, etc., manufactured by Kyoeisha Chemical Co., Ltd.), 2- (meth) acryloyloxyethyl-phosphate esters (Light Ester P-1M, P-2M, etc. manufactured by Kyoeisha Chemical Co., Ltd.), (meth) acrylic Acid ethoxylated-o-phenylphenol, (meth) acrylic acid methoxypolyethylene glycol (Kyoeisha Chemical Light Ester MC, 130MA, 041MA, MTG, MTG-A, 130A, Shin-Nakamura Chemical M-90G, AM-90G, M -230G, AM130G, Hitachi Chemical Funkrill FA-400M, NOF Corporation Renmer PME-100, PME-200, PME-400, PME-550, PME-1000, PME-4000, AME-400, etc.) (Meth) acrylic acid phenoxy polyethylene glycol (Kyoeisha Chemical Light Acrylate P-200A, New Nakamura Chemical AMP-20GY, NOF Blemmer PAE-50, PAE-100, AAE-50, AAE-300, Toagosei Aronix M-101, M-102, etc.), (meth) acrylic acid paracumylphenoxyethyl , (Meth) acrylic acid nonylphenoxypolyethylene glycol (Kyoeisha Chemical Light Acrylate NP-4EA, NP-8EA, Hitachi Chemical Funkrill FA-314A, FA-318A, NOF Bremer ANE-1300, Toagosei M- 111, M113, M- 17), (meth) acrylic acid octoxypolyethylene glycol-polypropylene glycol, (meth) acrylic acid lauroxypolyethylene glycol, (meth) acrylic acid stearoxypolyethylene glycol, (meth) acrylic acid phenoxy-polyethylene glycol-polypropylene glycol, (Meth) acrylic acid nonylphenoxy-polyethylene glycol-polypropylene glycol, (meth) acrylic acid 3-chloro-2-hydroxypropyl, (meth) acrylic acid 2- (2-vinyloxyethoxy) ethyl, (meth) acrylic acid ali Roxypolyethylene glycol-polypropylene glycol, undecylenoxy (meth) acrylate, undecylenoxypolyethylene glycol (meth) acrylate, (meth) acrylic acid ω-cap Ruboxy-polycaprolactone (M-5300 manufactured by Toagosei Co., Ltd.), Acrylic acid dimer (M-5600 manufactured by Toagosei Co., Ltd., β-CEA manufactured by Daicel Cytec), (Meth) acrylic acid N-ethylmaleimide, (Meth) acrylic acid penta Methylpiperidinyl, tetramethylpiperidinyl (meth) acrylate, γ- (methacryloyloxypropyl) trimethoxysilane, γ- (methacryloyloxypropyl) triethoxysilane, γ- (methacryloyloxypropyl) methyldimethoxysilane, ( 2- (ethyl methacrylate) 2-isocyanatoethyl acrylate, 2- (0- [1'-methylpropylideneamino] carboxyamino) ethyl (meth) acrylate, 2-[(3,5-dimethylpyrazolyl) carbonyl (meth) acrylate Amino] ethyl, (meth) acrylic acid Lead, potassium (meth) acrylate, sodium (meth) acrylate, magnesium (meth) acrylate, calcium (meth) acrylate, barium (meth) acrylate, strontium (meth) acrylate, nickel (meth) acrylate , Copper (meth) acrylate, aluminum (meth) acrylate, lithium (meth) acrylate, neodymium (meth) acrylate, trifluoromethylmethyl (meth) acrylate, 2,2,2- (meth) acrylate Trifluoroethyl, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, perfluoroethyl methyl (meth) acrylate, (meth) acryl 2-perfluoroethyl ethyl acid, perfluoroethyl (meth) acrylate Perfluorobutylmethyl, 2- (perfluoroethyl) 2- (perfluoroethyl) (meth) acrylate, perfluoroethyl (meth) acrylate, perfluoromethyl (meth) acrylate, diperfluoromethyl (meth) acrylate Methyl, 2,2-di-perfluoromethyl ethyl (meth) acrylate, perfluoromethyl perfluoroethyl methyl (meth) acrylate, 2-perfluoromethyl-2-perfluoroethyl ethyl (meth) acrylate, ( (Meth) acrylic acid 2-perfluorohexylmethyl, (meth) acrylic acid 2-perfluorohexylethyl, (meth) acrylic acid 2-perfluorodecylmethyl, (meth) acrylic acid 2-perfluorodecylethyl, (meth) 2-perfluorohexadecylmethyl acrylate, (meta And acrylic acid 2-perfluoroalkyl-hexadecyl ethyl and the like.

  These may be used alone or a plurality of these may be copolymerized. Here, (meth) acryl represents acryl and / or methacryl.

  The main chain of the (meth) acrylic polymer (D) having a double bond capable of reacting at the time of vulcanization of the diene rubber in the present invention is easy to mix the rubber composition and low temperature of the cured product. From the viewpoint of excellent physical properties such as flexibility and elongation, it is preferable to be produced mainly by polymerizing acrylate monomers. Here, “mainly” means that 50 mol% or more of the monomer units constituting the (meth) acrylic polymer (D) is an acrylate ester monomer, preferably 70 mol% or more. is there.

  Particularly preferred acrylic ester monomers include acrylic acid alkyl ester monomers, specifically ethyl acrylate, acrylic acid, acrylic acid-n-butyl, acrylic acid-tert-butyl, acrylic acid 2-ethylhexyl, Stearyl acrylate.

  In the present invention, these preferable monomers may be copolymerized with other monomers, and further block copolymerized. Examples of the monomer to be copolymerized include styrene monomers such as styrene, vinyl toluene, α-methyl styrene, chlorostyrene, styrene sulfonic acid, and salts thereof; fluorine-containing vinyl such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride. Monomers; Silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl and dialkyl esters of maleic acid; fumaric acid, monoalkyl and dialkyl esters of fumaric acid; maleimide , Methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclamate Maleimide monomers such as hexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, Examples thereof include vinyl esters such as vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, allyl chloride, and allyl alcohol.

  Molecular weight distribution of (meth) acrylic polymer (D) in the present invention, that is, ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) measured by gel permeation chromatography (GPC) (Mw / Mn) Is not particularly limited, but is preferably less than 1.8, more preferably 1.7 or less, even more preferably 1.6 or less, even more preferably 1.5 or less, and particularly preferably 1.4 or less, and most preferably 1.3 or less. When the molecular weight distribution is too large, not only is handling difficult, but control of the temperature characteristics of the resulting rubber composition and cured product tends to be difficult. In the GPC measurement in the present invention, chloroform is used as the mobile phase, the measurement is performed with a polystyrene gel column, and the number average molecular weight and the like can be determined in terms of polystyrene.

  The number average molecular weight of the (meth) acrylic polymer (D) in the present invention is not particularly limited, but when measured by GPC, a range of 500 to 1,000,000 is preferable, and 1,000 to 100,000. Is more preferable, and 5,000 to 100,000 is more preferable. If the molecular weight is too low, the effect of adding the (meth) acrylic polymer (D) cannot be obtained sufficiently, and it becomes difficult to balance the rolling resistance and the wet grip property. On the other hand, if it is too high, handling tends to be difficult.

<< Synthesis of (meth) acrylic polymer >>
The (meth) acrylic polymer (D) used in the present invention is not particularly limited and can be obtained by a conventionally known polymerization method. Among these, the radical polymerization method or the anion polymerization method is preferable from the viewpoint of versatility of the monomer and easy introduction of a double bond at the terminal. The radical polymerization can be classified into a “chain transfer agent method” and a “living radical polymerization method”. As the chain transfer agent method, as described in JP-A-9-104718, a (meth) acrylic monomer is polymerized in the presence of a chain transfer agent having a carboxyl group and then reacts with the carboxyl group. A method of introducing a radical polymerizable group such as a (meth) acryloyl group into one end of a polymer by reacting a compound having a glycidyl group or a hydroxyl group as a functional group is common. As the “living radical polymerization method”, for example, as described in JP-A-2005-232419, JP-A-2006-291073, etc., an organic halide is used as an initiator and a transition metal complex is used as a polymerization catalyst. Can be used to polymerize (meth) acrylic monomers to convert the terminal halogen functionality to the desired double bond.

  The atom transfer radical polymerization will be briefly described below.

  In atom transfer radical polymerization, an organic halide, particularly an organic halide having a highly reactive carbon-halogen bond (for example, a carbonyl compound having a halogen at the α-position or a compound having a halogen at the benzyl-position), or a sulfonyl halide. A compound or the like is preferably used as an initiator.

  There is no restriction | limiting in particular as a (meth) acrylic-type monomer used in atom transfer radical polymerization, All the (meth) acrylic-type monomers illustrated can be used suitably.

  Although it does not specifically limit as a transition metal complex used as a polymerization catalyst, Preferably it is a metal complex which uses a periodic table group 7, 8, 9, 10, or 11 element as a central metal, More preferably, it is 0. A transition metal complex having valent copper, monovalent copper, divalent ruthenium, divalent iron, or divalent nickel as a central metal, particularly preferably a copper complex. Specific examples of the monovalent copper compound used to form the copper complex include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, and oxidized oxide. Cuprous, cuprous perchlorate, and the like. In the case of using a copper compound, 2,2′-bipyridyl or a derivative thereof, 1,10-phenanthroline or a derivative thereof, tetramethylethylenediamine, pentamethyldiethylenetriamine, hexamethyltriethylenetetraamine or hexamethyltris ( Polyamines such as 2-aminoethyl) amine are added as ligands.

The polymerization reaction can be carried out without solvent, but can also be carried out in various solvents. It does not specifically limit as a kind of solvent, The solvent of Unexamined-Japanese-Patent No. 2005-232419 Paragraph [0067] is mentioned. These may be used alone or in combination of two or more. Polymerization can also be performed in an emulsion system or a system using supercritical fluid CO ₂ as a medium.

  Although superposition | polymerization temperature is not limited, It can carry out in the range of 0-200 degreeC, Preferably, it is the range of room temperature-150 degreeC.

<< Introduction method of double bond >>
As a method for introducing a double bond capable of reacting at the time of vulcanization of the diene rubber used in the present invention, a known method can be used. Examples of the method for introducing an alkenyl group include the methods described in paragraphs [0085] to [0098] of JP-A-2007-302749. Among these methods, since control is easier, (Ab) when synthesizing a (meth) acrylic polymer by living radical polymerization, at the end of the polymerization reaction or after completion of the reaction of a predetermined monomer, for example, A method of reacting a compound having at least two alkenyl groups having low polymerizability such as 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene and the like is preferable.

  Examples of the method for introducing a (meth) acryloyl group include the methods described in paragraphs [0080] to [0091] of JP-A-2004-203932. Among these methods, from the viewpoint of easier control, it is preferable that the method is produced by substituting the terminal halogen group of the (meth) acrylic polymer with a compound having a (meth) acryloyl group.

  The (meth) acrylic polymer having a terminal halogen group is a method of polymerizing vinyl monomers using the above-described organic halides or sulfonyl halide compounds as initiators and transition metal complexes as catalysts, or chain transfer of halogen compounds. Although it is manufactured by a method of polymerizing a vinyl monomer as an agent, the former is preferred.

Although it does not specifically limit as a compound which has a (meth) acryloyl group, The compound represented by following General formula (1) can be used,
M ⁺ -OC (O) C (R) = CH ₂ (1)
Specific examples of R in the above formula (1) include, for example, —H, —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) _n CH ₃ (n represents an integer of 2 to 19), — _{C 6 H 5, -CH 2 OH} , -CN, etc., and is preferably -H, -CH _3.

M ⁺ in the above formula (1) is a counter cation of an oxyanion, and examples of M ⁺ include alkali metal ions, specifically lithium ions, sodium ions, potassium ions, and quaternary ammonium ions. Examples of the quaternary ammonium ion include tetramethylammonium ion, tetraethylammonium ion, tetrabenzylammonium ion, trimethyldodecylammonium ion, tetrabutylammonium ion and dimethylpiperidinium ion, and are preferable from the viewpoint of reactivity and availability. Are sodium ion and potassium ion.

  The usage-amount of the oxyanion of General formula (1) becomes like this. Preferably it is 1-5 equivalent with respect to a halogen group, More preferably, it is 1.0-1.2 equivalent. Since this reaction proceeds almost quantitatively, if the amount is too small, a sufficient amount of (meth) acryloyl groups is not introduced relative to the halogen group, and if the amount is too large, it is economically undesirable.

  The solvent for carrying out this reaction is not particularly limited but is preferably a polar solvent because it is a nucleophilic substitution reaction. For example, tetrahydrofuran, dioxane, diethyl ether, acetone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, hexamethylphosphoric Triamide, acetonitrile and the like are used.

  Although the temperature which performs reaction is not limited, Generally it is 0-150 degreeC, In order to hold | maintain a polymeric terminal group, Preferably it carries out at room temperature-100 degreeC.

  In the present invention, the (meth) acrylic polymer (D) may have at least one or more functional groups in one molecule as necessary. The functional group is preferably at least one functional group selected from a carboxyl group, a hydroxyl group, an ether group, an amide group, an amino group, a hydrolyzable silyl group, an epoxy group, an acid anhydride group, and an active chlorine group. . By introducing a functional group, the dispersibility and bonding strength with rubber component (A), white filler (B), and carbon black (C), as well as rolling resistance and wet grip properties are improved. Adhesiveness between the object and the rubber parts constituting the tire can be imparted. Furthermore, it can utilize as a crosslinking point using a functional group.

  In the present invention, the functional group is a carboxyl group, in terms of heat resistance, dispersibility with the rubber component (A), imparting adhesion, ease of introduction into the (meth) acrylic polymer (D), cost, and the like. It is preferably at least one selected from an acid anhydride group, a hydroxyl group, and an epoxy group.

  The content of these functional groups can be appropriately selected from the dispersibility, viscosity, dynamic viscoelasticity, and reactivity required as a rubber composition for a pneumatic tire, but when the content increases (meta ) The glass transition temperature of the acrylic polymer (D) becomes high or the interaction with the white filler (B) becomes strong, so that kneading may become difficult. From the viewpoints of flexibility, rubber elasticity, and kneadability Therefore, the content in the (meth) acrylic polymer (D) is preferably 20% by weight or less, and more preferably 10% by weight or less.

  The method for introducing the functional group into the acrylic polymer is not particularly limited. The method includes copolymerizing a monomer having a functional group, and copolymerizing a monomer having a functional group that serves as a precursor of the functional group. Thereafter, there is a method of generating a functional group by a known chemical reaction.

  Examples of the monomer having a carboxyl group include unsaturated carboxylic acid compounds such as (meth) acrylic acid, unsaturated dicarboxylic acid compounds such as maleic acid and fumaric acid, and monoester compounds thereof. Moreover, a carboxyl group can be converted from a functional group serving as a precursor thereof. Examples of the monomer having a functional group serving as a precursor of a carboxyl group include t-butyl (meth) acrylate, trimethylsilyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid α, α. -Dimethylbenzyl, (meth) acrylic acid α-methylbenzyl, maleic anhydride and the like. After these monomers are polymerized, a carboxyl group can be generated by hydrolysis, acid decomposition, thermal decomposition or the like.

  Examples of the monomer having an acid anhydride group include maleic anhydride. Moreover, as a functional group used as the precursor of an acid anhydride group, a carboxyl group is mentioned, As a method of introduce | transducing a carboxyl group, the said method can be mentioned.

  Examples of the monomer having a hydroxyl group include (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-3-hydroxypropyl, and (meth) acrylic acid. -4-hydroxybutyl, glycerin mono (meth) acrylate, Blemmer PE series (Nippon Yushi Co., Ltd.), Blemmer AE series (Nippon Yushi Co., Ltd.), Blemmer P (Nippon Yushi Co., Ltd.), Blemmer PP series (Japan) Oil & Fat Co., Ltd., Blemmer AP Series (Nippon Yushi Co., Ltd.), Blemmer PEP Series (Nippon Yushi Co., Ltd.), Blemmer AEP Series (Nippon Yushi Co., Ltd.), Blemmer PET Series (Nippon Yushi Co., Ltd.), Blemmer AET series (Nippon Yushi Co., Ltd.), Blemmer PPT series (Nippon Yushi) Co., Ltd.)), Brenmer APT series (Nippon Oil & Fats Co., Ltd.), and the like.

  Examples of the monomer having an epoxy group include glycidyl (meth) acrylate, 2,3-epoxy-2-methylpropyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, and the like ( Examples thereof include esters of (meth) acrylic acid with an organic group-containing alcohol containing an epoxy ring, and epoxy group-containing unsaturated compounds such as 4-vinyl-1-cyclohexene 1 and 2 epoxides.

<Other additives>
In addition to the above, the rubber composition of the present invention is generally used in the rubber industry for the purpose and use of compounding agents such as fillers, plasticizers, vulcanizing agents, vulcanization accelerators, and anti-aging agents. It can mix | blend suitably according to. Examples of the filler include aluminum oxide, organic short fibers, (meth) acrylic resin fine particles, epoxy resin fine particles, glass fine particles, glass fibers, and flake graphite in addition to the above-described carbon black and white filler. Plasticizers include paraffinic process oil, naphthenic process oil, petroleum process oil such as aromatic process oil, dibasic acid dialkyl such as diethyl phthalate, dioctyl phthalate and dibutyl adipate, liquid polybutene, liquid poly Examples include low molecular weight liquid polymers such as isoprene, and natural oils such as orange oil. Among these, liquid polybutene, liquid polyisoprene, and aromatic process oil are preferable because of compatibility with the rubber component. Examples of the vulcanizing agent include sulfur, phenol resin, metal oxide, peroxide and the like. These are usually used in an amount of about 0.5 to 10 parts per 100 parts by weight of the rubber component. Examples of the vulcanization accelerator include 2-mercaptobenzothiazole (M), 2,2-dithiobisbenzothiazole (DM), mercaptobenzothiazole zinc salt (MZ), mercaptobenzothiazolecyclohexylamine salt (M60), 2 , 4-dinitrophenylthiobenzothiazole (DBM), thiazole vulcanization accelerators such as N, N-diethylthiocarbamoylthiobenzothiazole (64), N-cyclohexyl-2-benzothiazoylsulfenamide (CZ), N-tert-butyl-2-benzothiazole sulfenamide (NS), N-oxydiethylene-2-benzothiazoyl sulfenamide (NOBS), N, N-dicyclohexyl-2-benzothiazoyl sulfenamide (DZ ), Morpholinodithiobenzothiazole (MDB) sulfenamide vulcanization accelerators, hexamethylenetetramine (H) amine vulcanization accelerators, butyraldehyde aniline (B), butyraldehyde monobutylamine (833) aldehyde ammonia vulcanization Accelerators, guanidines such as diphenylguanidine (D), di-o-tolylguanidine (DT), o-tolylguanidine (BG), dicatecholboric acid-di-o-tolylguanidine salt (PR), tetramethylthiuram Promotion of thiuram vulcanization such as monosulfide (TS), tetramethyl thiuram disulfide (TT), tetraethyl thiuram disulfide (TET), tetrabutyl thiuram disulfide (TBT), dipentamethylene thiuram hexasulfide (TRA), tetrabenzyl thiuram disulfide Agent It is. These are usually used in an amount of about 0.2 to 5 parts per 100 parts by weight of the rubber component. A vulcanization accelerator may be used individually by 1 type, and may use 2 or more types together.

The rubber composition of the present invention can further contain a silane coupling agent.
When silica is used as the white filler, a silane coupling agent may be added at the time of blending from the viewpoint of further improving the reinforcement.

  Examples of the silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, and bis (2-triethoxy). Silylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyl Triethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxy Rylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl Methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropylbenzothiazole tetrasulfide, N -(1,3-Dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, vinyltrimethoxy Run, vinyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-glycidoxypropyltri Methoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-mercaptopropyltrimethoxysilane , Γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, γ-mercaptopropylmethyldiethoxysilane, and the like.

  Among these, bis (3-triethoxysilylpropyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and γ-acryloxypropyl are superior in terms of wear resistance and from the viewpoint of reinforcing effect. Triethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriethoxysilane, and styryltriethoxysilane are preferred.

  A silane coupling agent can be used individually or in combination of 2 types or more, respectively.

<Method for adjusting rubber composition>
The method for preparing the rubber composition of the present invention employs a method conventionally used in the rubber industry, and the method for producing the rubber composition of the present invention is not particularly limited. Examples thereof include a kneading method using an apparatus (for example, a Banbury mixer, a kneader, a roll, etc.).

  As kneading conditions, when additives other than the vulcanizing agent and the vulcanization accelerator are blended, the kneading temperature is usually 50 to 200 ° C., preferably 80 to 190 ° C., and the kneading time is usually 30 seconds. -30 minutes, preferably 1-30 minutes.

  When blending a vulcanizing agent and a vulcanization accelerator, the kneading temperature is usually 100 ° C. or lower, preferably room temperature to 80 ° C. A composition containing a vulcanizing agent and a vulcanization accelerator is usually used after vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 120 to 200 ° C, preferably 140 to 180 ° C.

<Pneumatic tire, pneumatic tire tread>
The pneumatic tire of the present invention is produced by a usual method using the rubber composition. That is, a rubber composition containing various additives as necessary is extruded in accordance with the shape of the tread of the tire at an unvulcanized stage, molded by a normal method on a tire molding machine, etc. The tire members are bonded together to form an unvulcanized tire. This unvulcanized tire can be heated and pressurized in a vulcanizer to produce the pneumatic tire of the present invention.

  The pneumatic tire of the present invention can be suitably used as a tire for passenger cars and a tire for trucks and buses (heavy load tire).

  When the rubber composition of the present invention is used for a pneumatic tire, the performance of the tire is estimated by the following index.

  The wet grip property is considered to depend on deformation near the surface of the tire. This deformation near the surface is known to be a vibration of a very high frequency, and when using temperature frequency conversion, the wet grip property is expressed by tan δ of −20 ° C. to 0 ° C. at 10 Hz. On the other hand, the rolling resistance is a vibration of about 10 to 100 Hz around 60 ° C., and is expressed by tan δ of 40 ° C. to 70 ° C. at 10 Hz. Therefore, both rolling resistance and wet grip can be achieved by increasing tan δ of −20 ° C. to 0 ° C. and decreasing tan δ of 40 ° C. to 70 ° C.

  The running stability is expressed by a small change in elastic modulus at 40 ° C to 90 ° C.

  Specific examples of the present invention will be described below together with comparative examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, “part” and “%” represent “part by weight” and “% by weight”, respectively. “Number average molecular weight” and “molecular weight distribution (ratio of weight average molecular weight to number average molecular weight)” were calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC). However, a GPC column filled with polystyrene cross-linked gel (shodex GPC K-804, K-802.5; manufactured by Showa Denko KK) was used as the GPC solvent with chloroform.

The number of functional groups introduced per molecule of polymer was calculated based on the concentration analysis by ¹ H-NMR and the number average molecular weight determined by GPC. NMR was measured at 23 ° C. using Bruker ASX-400 and deuterated chloroform as a solvent.

<Rolling resistance>
A test piece having a length of 40 mm, a width of 5 mm, and a thickness of 2 mm was cut out from the vulcanized rubber cured product, and a dynamic strain was measured using a dynamic viscoelasticity measuring device DVA-200 (manufactured by IT Measurement Control Co., Ltd.). The tan δ at 70 ° C. was measured under the conditions of 1% and 10 Hz.
About this characteristic, it showed with the index | exponent which makes a reference | standard sample (after-mentioned comparative example 1) 100. The smaller this index, the better the rolling resistance.

<Wet grip>
A test piece having a length of 40 mm, a width of 5 mm, and a thickness of 2 mm was cut out from the vulcanized rubber cured product, and a dynamic strain was measured using a dynamic viscoelasticity measuring device DVA-200 (manufactured by IT Measurement Control Co., Ltd.). Tan δ at 0 ° C. was measured under the conditions of 0.1% and 10 Hz.

  About this characteristic, it showed with the index | exponent which makes a reference | standard sample (after-mentioned comparative example 1) 100. The larger this index, the better the wet grip.

<Rolling resistance / wet grip balance>
The ratio of the index calculated in terms of rolling resistance and wet grip (wet grip index / rolling resistance index) was shown as an index with the reference sample (Comparative Example 1 described later) as 100. The larger this value is, the better the balance between rolling resistance and wet grip property is. When the value is smaller than 100, the balance is worse than the reference sample.

<Running stability>
A test piece having a length of 40 mm, a width of 5 mm, and a thickness of 2 mm was cut out from the vulcanized rubber cured product, and a dynamic strain was measured using a dynamic viscoelasticity measuring device DVA-200 (manufactured by IT Measurement Control Co., Ltd.). The storage modulus at 50 ° C. and 90 ° C. was measured under the conditions of 1% and 10 Hz. About this characteristic, ratio of the storage elastic modulus in 50 degreeC and 90 degreeC was shown by the index | exponent which makes a reference | standard sample (Comparative Example 1 mentioned later) 100. The smaller this index is, the smaller the change in elastic modulus with temperature, indicating that the running performance with respect to the speed change is more stable.

(Synthesis example 1) Synthesis example of poly (n-butyl acrylate) polymer [P1] having an acryloyl group According to a known method, cuprous bromide as a catalyst, pentamethyldiethylenetriamine as a ligand, α-bromobutyric acid Ethyl was used as an initiator, and n-butyl acrylate was used as a monomer, and polymerization was carried out at a (n-butyl acrylate) / (ethyl α-bromobutyrate) ratio of 80 to obtain a terminal bromine group poly (n-butyl acrylate).

  This polymer was dissolved in N, N-dimethylacetamide, potassium acrylate and a heat stabilizer were added, and the mixture was heated and stirred at 70 ° C. in a nitrogen atmosphere. N, N-dimethylacetamide in this mixed solution was distilled off under reduced pressure, butyl acetate was added to the residue, and insoluble matter was removed by filtration. The butyl acetate in the filtrate was distilled off under reduced pressure to obtain a poly (n-butyl acrylate) polymer [P1] having an acryloyl group at one end.

The number average molecular weight of the obtained polymer [P1] was about 12,000, and the molecular weight distribution was 1.1. When the average number of acryloyl groups introduced per polymer molecule was determined by ¹ H-NMR analysis, it was about 0.9.

(Synthesis example 2) Synthesis example of poly (n-butyl acrylate) polymer [P2] having an acryloyl group One end of the polymer as in Synthesis example 1 except that the monomer / initiator ratio is 40 A poly (n-butyl acrylate) polymer [P2] having an acryloyl group was obtained.

The number average molecular weight of the obtained polymer [P2] was about 6500, and the molecular weight distribution was 1.2. When the average number of acryloyl groups introduced per polymer molecule was determined by ¹ H-NMR analysis, it was about 0.9.

(Synthesis Example 3) Synthesis Example of Poly (n-butyl acrylate) Polymer [P3] Having an Alkenyl Group Acetonitrile was added as a solvent to the terminal bromine group poly-acrylate n-butyl synthesized in Synthesis Example 1, and 1 , 7-octadiene was reacted. Acetonitrile and excess 1,7-octadiene were distilled off under reduced pressure, butyl acetate was added to the residue, and insolubles were removed by filtration. The butyl acetate in the filtrate was distilled off under reduced pressure to obtain a poly (n-butyl acrylate) polymer [P3] having an alkenyl group at one end.

The number average molecular weight of the obtained polymer [P3] was about 13,000, and the molecular weight distribution was 1.1. When the average number of alkenyl groups introduced per molecule of the polymer was determined by ¹ H-NMR analysis, it was about 0.9.

(Synthesis example 4) Synthesis example of poly (n-butyl acrylate) / (acrylic acid) copolymer [P4] having an acryloyl group In the same manner as in Synthesis example 1, cuprous bromide as a catalyst, pentamethyldiethylenetriamine Is the ligand, ethyl α-bromobutyrate is the initiator, n-butyl acrylate / t-butyl acrylate (90/10 by weight) is the monomer, and the monomer / (ethyl α-bromobutyrate) ratio is 80. The terminal bromine group poly (n-butyl acrylate) / (t-butyl acrylate) copolymer was obtained.

  This polymer was similarly treated with potassium acrylate to obtain a poly (n-butyl acrylate) / (t-butyl acrylate) copolymer having an acryloyl group at one end.

P-Toluenesulfonic acid is added to the obtained copolymer as an acid catalyst, and the reaction is carried out at 110 ° C. under reduced pressure by heating to obtain a poly (n-butyl acrylate) / (acrylic acid) copolymer [P4]. It was. The number average molecular weight of the copolymer [P4] was about 9900, and the molecular weight distribution was 1.2. When the average number of acryloyl groups introduced per molecule of the polymer was determined by ¹ H-NMR analysis, it was about 1.0.

(Synthesis example 5) Synthesis example of poly (methoxyethyl acrylate) polymer having acryloyl group [P5] Except for using methoxyethyl acrylate as a monomer, poly having acryloyl group at one end in the same manner as synthesis example 1 (Methoxyethyl acrylate) polymer [P5] was obtained.

The number average molecular weight of the obtained polymer [P5] was about 11,000, and the molecular weight distribution was 1.1. When the average number of acryloyl groups introduced per polymer molecule was determined by ¹ H-NMR analysis, it was about 0.8.

(Comparative Synthesis Example X1) Synthesis example of poly (n-butyl acrylate) polymer [PX1] having acryloyl group Cuprous bromide as catalyst, pentamethyldiethylenetriamine as ligand, diethyl-2,5-dibromoadipate And an n-butyl acrylate as a monomer, and polymerization is carried out with a (n-butyl acrylate) / (diethyl-2,5-dibromoadipate) ratio of 80 to obtain a terminal bromine group poly-n-butyl acrylate. It was.

  This polymer was dissolved in N, N-dimethylacetamide, potassium acrylate was added, and the mixture was heated and stirred at 70 ° C. in a nitrogen atmosphere. N, N-dimethylacetamide in this mixed solution was distilled off under reduced pressure, butyl acetate was added to the residue, and insoluble matter was removed by filtration. The butyl acetate in the filtrate was distilled off under reduced pressure to obtain a poly (n-butyl acrylate) polymer [PX1] having acryloyl groups at both ends.

The number average molecular weight of the polymer [PX1] was 12,000, the molecular weight distribution was 1.2, and the average number of acryloyl groups introduced per polymer molecule was determined by ¹ H-NMR analysis to be about 1.8. It was a piece.

(Comparative Synthesis Example X2) Synthesis Example of Poly (n-butyl acrylate ) Polymer Having Silyl Group [PX2] Poly (n-butyl acrylate) polymer having an alkenyl group at one end synthesized in Synthesis Example 3 Methyldimethoxysilane is added to [P3], and an isopropanol solution of [bis (1,3-divinyl-1,1,3,3-tetramethyldisiloxane) platinum complex] as a platinum catalyst is mixed and heated to 110 ° C. The hydrosilylation reaction was performed by heating. Unreacted methyldimethoxysilane was distilled off under reduced pressure to obtain a poly (n-butyl acrylate) polymer [PX2] having a silyl group at one end.

The number average molecular weight of the obtained polymer [PX2] was about 13,000, and the molecular weight distribution was 1.1. When the average number of silyl groups introduced per polymer molecule was determined by ¹ H-NMR analysis, it was about 0.9.

(Comparative Synthesis Example X3) Synthesis Example of Poly (n-butyl acrylate) Polymer [PX3] Having Silyl Group Cuprous bromide as catalyst, pentamethyldiethylenetriamine as ligand, diethyl-2,5-dibromoadipate Is used as an initiator, and n-butyl acrylate is used as a monomer, and polymerization is carried out with a (n-butyl acrylate) / (diethyl-2,5-dibromoadipate) ratio of 160 to obtain terminal bromine group poly (n-butyl acrylate). It was. 1,7-octadiene was reacted with this terminal bromine group poly (butyl acrylate) to obtain a poly (n-butyl acrylate) polymer having alkenyl groups at both ends.

  This poly (n-butyl acrylate) polymer having alkenyl groups at both ends is reacted with methyldimethoxysilane using a hydrosilylation reaction, and poly (n-butyl acrylate) having hydrolyzable silyl groups at both ends. ) A polymer [PX3] was obtained.

The number average molecular weight of the obtained polymer [PX3] was about 25000, and the molecular weight distribution was 1.3. When the average number of silyl groups introduced per molecule of the polymer was determined by ¹ H-NMR analysis, it was about 2.0.

Example 1
Emulsion polymerization method Styrene-butadiene rubber (Nipol 1502, manufactured by Nippon Zeon Co., Ltd.) 100 parts by weight, (meth) acrylic polymer synthesized in Synthesis Example 1 [P1] 3 parts by weight, silica AQ (Tosoh Silica Co., Ltd.) as a white filler 50 parts by weight, Asahi # 70 (manufactured by Asahi Carbon Co., Ltd.) as carbon black, 10 parts by weight as softening agent, 30 parts by weight of Aromax 3 (manufactured by Fujikosan), stearic acid (reagent: Wako Pure Chemical Industries, Ltd.) 2 Labo plast mill (Toyo) which set 2 parts by weight of zinc oxide (zinc oxide, reagent: Wako Pure Chemical Industries) 2 parts by weight and 2 parts by weight of NOCRACK 810-NA (manufactured by Ouchi Shinsei) as an antioxidant. After kneading for 15 minutes using Seiki Co., Ltd., the mixture was once taken out and cooled. The mixture was again put into a lab plast mill so that the resin temperature did not exceed 90 ° C., 2 parts by weight of sulfur (reagent: Wako Pure Chemical Industries, Ltd.) as a vulcanizing agent, and N-tert-butyl as a vulcanization accelerator. 2-benzothiazolesulfenamide (reagent: Wako Pure Chemical Industries, Ltd.) 1.5 parts by weight and N, N′-diphenylguanidine (reagent: Wako Pure Chemical Industries, Ltd.) 1.5 parts by weight were added, and 5 minutes. A rubber composition was obtained by kneading. The rubber composition was press-molded at 170 ° C. for 30 minutes to produce a sheet having a thickness of 2 mm. The moldability was very good. A test piece was cut out from the sheet, and the dynamic viscoelasticity was measured to evaluate rolling resistance, wet grip property, and running stability.

(Examples 2 to 5)
As a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of a diene rubber at the molecular end, as shown in Table 1, instead of (meth) acrylic polymer [P1] ) A sheet was prepared from the rubber composition in the same manner as in Example 1 except that the indicated number of acrylic polymers [P2] to [P5] were added, and the dynamic viscoelasticity was measured.

(Comparative Example 1)
A sheet was prepared from the rubber composition in the same manner as in Example 1 except that no (meth) acrylic polymer was added, and dynamic viscoelasticity was measured.

(Comparative Example 2)
Instead of the (meth) acrylic polymer [P1], a sheet is formed from the rubber composition in the same manner as in Example 1 except that 3 parts of a (meth) acrylic polymer [PX1] having acryloyl groups at both ends is added. The dynamic viscoelasticity was measured.

(Comparative Example 3)
A rubber composition in the same manner as in Example 1 except that 3 parts of (meth) acrylic polymer [PX2] having a hydrolyzable silyl group at one end is added instead of (meth) acrylic polymer [P1]. Sheets were prepared from the objects, and dynamic viscoelasticity was measured.

(Comparative Example 4)
A rubber composition in the same manner as in Example 1 except that 3 parts of a non-functional acrylic oligomer obtained by high-temperature continuous polymerization method using n-butyl acrylate instead of (meth) acrylic polymer [P1] is added. Sheets were prepared from the objects, and dynamic viscoelasticity was measured.

(Comparative Example 5)
A sheet was prepared from the rubber composition in the same manner as in Example 1 except that 5 parts of a silane coupling agent KBE-846 made by Shin-Etsu Chemical was added instead of the (meth) acrylic polymer [P1]. Elasticity was measured.

  In the case of Examples 1 and 2, compared with the case where nothing is added (Comparative Example 1) by adding a (meth) acrylic polymer having a double bond capable of reacting at the end of the molecular piece at the time of vulcanization of the diene rubber. Thus, the rolling resistance is almost the same, the wet grip property is remarkably improved, and the balance of rolling resistance / wet grip property is improved by 10% or more. Furthermore, since the running stability is improved by 20% or more, it is useful as a rubber composition and a tire excellent in the balance of contradictory characteristics such as rolling resistance and wet grip property and also in running stability. In Example 3, the wet grip property is slightly lower, but the rolling resistance is improved, and the balance of rolling resistance / wet grip property is also considerably improved. In addition, the running stability is improved by 10% or more. In Example 4, although the wet grip property is slightly lowered, the rolling resistance is remarkably improved, and the balance of rolling resistance / wet grip property and running stability are greatly improved. In Example 5, although the wet grip property is low, the rolling resistance is greatly improved, and the balance of the rolling resistance / wet grip property is improved by 20% as compared with the case of E-SBR alone (Comparative Example 1). ing. Furthermore, the running stability is improved by 30% or more.

  On the other hand, in Comparative Example 2, when a (meth) acrylic polymer having acryloyl groups at both ends was used, the wet grip was improved, but the rolling resistance was remarkably deteriorated, and the balance of rolling resistance / wet grip was improved. It is damaged. In addition, the running stability is significantly deteriorated. Similarly, in Comparative Example 3, the balance of rolling resistance / wet grip property is impaired, and the running stability is remarkably deteriorated. In Comparative Example 4, a non-functional acrylic oligomer obtained by a high temperature continuous polymerization method was used. This acrylic oligomer does not have a double bond capable of reacting at the terminal during vulcanization of the diene rubber. As a result, although excellent in running stability, the rolling resistance is remarkably deteriorated, and the balance of rolling resistance / wet grip property is also deteriorated. In Comparative Example 5, a silane coupling agent (bis-3-triethoxysilylpropyl tetrasulfide), which is a common additive in silica compounding for tire applications, was used. In this case, the rolling resistance and wet grip properties are slightly improved, but the running stability is remarkably deteriorated.

(Example 6)
Solution polymerization method Styrene-butadiene rubber (Nipol NS116R, manufactured by Nippon Zeon Co., Ltd.) 70 parts by weight, butadiene rubber (Nipol BR1220, manufactured by Nippon Zeon Co., Ltd.) 30 parts by weight, (meth) acrylic polymer synthesized in Synthesis Example 1 [P1 ] 3 parts by weight, silica AQ (manufactured by Tosoh Silica) as white filler, 10 parts by weight Asahi # 70 (manufactured by Asahi Carbon) as carbon black, Aromax 3 (manufactured by Fuji Kosan) as softener 30 parts by weight, stearic acid (reagent: Wako Pure Chemical Industries, Ltd.) 2 parts by weight, zinc white (zinc oxide, reagent: Wako Pure Chemical Industries, Ltd.) 2 parts by weight, NOCRACK 810-NA (Ouchi Shinsei Co., Ltd.) as an antioxidant (Made) After kneading (primary kneading) for 15 minutes using a lab plast mill (manufactured by Toyo Seiki Co., Ltd.) with 2 parts by weight set to 80 ° C., the mixture was once taken out and cooled. The mixture was again put into a lab plast mill so that the resin temperature did not exceed 90 ° C., 2 parts by weight of sulfur (reagent: Wako Pure Chemical Industries, Ltd.) as a vulcanizing agent, and N-tert-butyl as a vulcanization accelerator. 2-benzothiazolesulfenamide (reagent: Wako Pure Chemical Industries, Ltd.) 1.5 parts by weight and N, N′-diphenylguanidine (reagent: Wako Pure Chemical Industries, Ltd.) 1.5 parts by weight were added, and 5 minutes. The rubber composition was obtained by kneading (secondary kneading). The rubber composition was press-molded at 170 ° C. for 30 minutes to produce a sheet having a thickness of 2 mm. The moldability was very good. A test piece was cut out from the sheet, and the dynamic viscoelasticity was measured to evaluate rolling resistance, wet grip property, and running stability.

(Example 7)
Example 6 except that 1 part by weight of (meth) acrylic polymer [P1] is added as a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of the diene rubber at the molecular end. Similarly, a sheet was prepared from the rubber composition, and dynamic viscoelasticity was measured.

(Example 8)
As a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of a diene rubber at the molecular end, instead of the (meth) acrylic polymer [P1], one-terminal methacryloyl made by Toagosei Co., Ltd. A sheet was prepared from the rubber composition in the same manner as in Example 6 except that 3 parts by weight of the basic acrylic polymer macromonomer AB-6 was used, and the dynamic viscoelasticity was measured.

(Comparative Example 6)
A sheet was prepared from the rubber composition in the same manner as in Example 6 except that no (meth) acrylic polymer was added, and dynamic viscoelasticity was measured.

(Comparative Example 7)
Instead of the (meth) acrylic polymer [P1], a sheet is formed from the rubber composition in the same manner as in Example 6 except that 3 parts of a (meth) acrylic polymer [PX1] having acryloyl groups at both ends is added. The dynamic viscoelasticity was measured.

(Comparative Example 8)
Rubber composition as in Example 6 except that 3 parts of (meth) acrylic polymer [PX2] having a hydrolyzable silyl group at one end is added instead of (meth) acrylic polymer [P1] Sheets were prepared from the objects, and dynamic viscoelasticity was measured.

(Comparative Example 9)
Rubber composition as in Example 6 except that 5 parts of (meth) acrylic polymer [PX3] having hydrolyzable silyl groups at both ends is added instead of (meth) acrylic polymer [P1]. Sheets were prepared from the objects, and dynamic viscoelasticity was measured.

(Comparative Example 10)
A rubber composition in the same manner as in Example 6 except that 3 parts of a non-functional acrylic oligomer obtained by a high-temperature continuous polymerization method using n-butyl acrylate instead of the (meth) acrylic polymer [P1] is added. Sheets were prepared from the objects, and dynamic viscoelasticity was measured.

(Comparative Example 11)
Instead of the (meth) acrylic polymer [P1], 3 parts of MMA (methyl methacrylate) -BA (butyl acrylate) -MMA type acrylic block copolymer (BA / MMA = 80/20% by weight) Except for the addition, a sheet was prepared from the rubber composition in the same manner as in Example 1, and the dynamic viscoelasticity was measured.

(Comparative Example 12)
A sheet was prepared from the rubber composition in the same manner as in Example 6 except that 5 parts of a silane coupling agent KBE-846 made by Shin-Etsu Chemical was added instead of the (meth) acrylic polymer [P1]. Elasticity was measured.

  In the case of Example 6, the rolling resistance is higher than that in the case where nothing is added (Comparative Example 6) by adding a (meth) acrylic polymer having a double bond capable of reacting at the end of the molecular piece at the time of vulcanization of the diene rubber. The wet grip property is remarkably improved, and the balance of rolling resistance / wet grip property is improved by 50% or more. Furthermore, since the running stability is also improved by 30% or more, it is useful as a rubber composition and a tire excellent in the balance of conflicting characteristics such as rolling resistance and wet grip properties and also in running stability. Indicated. In both Examples 7 and 8, the rolling resistance or the wet grip property is improved by about 10% without greatly impairing the balance of the rolling resistance / wet grip property, and at the same time, the running stability is greatly improved.

  On the other hand, in Comparative Example 7, when a (meth) acrylic polymer having acryloyl groups at both ends was used, the wet grip property and rolling resistance deteriorated, and the balance of rolling resistance / wet grip property was not lost. The stability also deteriorated. In Comparative Example 8 using a (meth) acrylic polymer having a hydrolyzable silyl group at one end, no improvement in rolling resistance was observed, and only wet grip properties were slightly improved. As a result, rolling resistance / wet grip The balance of sex improved slightly, but the effect was limited. In Comparative Example 9 using a (meth) acrylic polymer having hydrolyzable silyl groups at both ends, not only the rolling resistance was not improved, but also the wet grip property deteriorated, and accordingly, the rolling resistance / wet grip property. As a result, the balance was significantly impaired. In Comparative Example 10 using the non-functional acrylic oligomer, the rolling resistance and the wet grip property were both deteriorated. In Comparative Example 11 using the acrylic block copolymer, the rolling resistance and wet grip property were more significantly deteriorated. In Comparative Example 12 using a silane coupling agent (bis-3-triethoxysilylpropyltetrasulfide), which is a common additive in silica compounding for tire applications, the wet grip property is improved, but the rolling resistance is deteriorated. Therefore, the balance of rolling resistance / wet grip property is equivalent to Comparative Example 6 in which nothing is added, and no improvement effect is observed.

  Although all of the additives used in Comparative Examples 7 to 12 are expected to improve by about 10% with respect to running stability, no effective improvement is observed in any of rolling resistance, wet grip properties, and balance between the two.

  However, in Examples 6 to 8 to which a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of the diene rubber was added, in addition to the improvement in running stability, A remarkable improvement effect is observed in any one or a plurality of rolling resistance, wet grip property and balance between the two.

Example 9
From the rubber composition to the sheet in the same manner as in Example 6, except that during the primary kneading of the rubber composition, the mixture was kneaded for 15 minutes with a lab plast mill set at 80 ° C., and then the kneading temperature was increased to 150 ° C. for 10 minutes. The dynamic viscoelasticity was measured.

(Example 10)
As a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of a diene rubber at the molecular fragment end, instead of the (meth) acrylic polymer [P1], a (meth) acrylic polymer [ 3 parts by weight of P4], 5 parts of silane coupling agent KBE-846 manufactured by Shin-Etsu Chemical Co., Ltd. were added and kneaded for 15 minutes in a lab plast mill set at 80 ° C. during the primary kneading of the rubber composition. A sheet was prepared from the rubber composition in the same manner as in Example 6 except that the kneading temperature was raised to 150 ° C. and kneading for 10 minutes, and the dynamic viscoelasticity was measured.

(Comparative Example 13)
From the rubber composition to the sheet in the same manner as in Comparative Example 12, except that during the primary kneading of the rubber composition, the mixture was kneaded for 15 minutes with a lab plast mill set at 80 ° C. and then the kneading temperature was raised to 150 ° C. for 10 minutes. The dynamic viscoelasticity was measured.

  In Examples 9 and 10, both the rolling resistance / wet grip balance and running stability were improved, but a silane coupling agent (bis-3-triethoxy), which is a general additive in silica compounding for tire applications, was used. In Comparative Example 13 using only silylpropyltetrasulfide), running stability is remarkably deteriorated.

  From the above results, by using a (meth) acrylic polymer having a double bond capable of reacting at the time of vulcanization of diene rubber at the end of the molecular piece, rolling resistance and / or wet grip properties are improved, or rolling resistance. / Provided is a rubber composition having an improved wet grip balance and excellent running stability.

Claims (9)

10 to 150 parts by weight of white filler (B) and / or carbon black (C) with respect to 100 parts by weight of diene rubber (A), and molecules capable of reacting during vulcanization of diene rubber It contains 0.5 to 20 parts by weight of (meth) acrylic polymer (D) at one end, and diene rubber (A) is natural rubber, isoprene rubber, styrene-butadiene copolymer rubber, and butadiene rubber. At least Tanedea Rukoto rubber composition characterized selected from the group consisting of. The white filler (B) 0 to 90 parts by weight and / or carbon black (C) 0 to 60 parts by weight with respect to 100 parts by weight of the diene rubber (A). Rubber composition. The white filler (B) is at least one selected from the group consisting of silica, clay, mica, talc, shirasu, calcium carbonate, magnesium carbonate, aluminum hydroxide, and barium sulfate. The rubber composition according to 1 or 2 . The reaction double bond during vulcanization of diene rubber (A), an alkenyl group, of claims 1 to 3, characterized in that at least one member selected from the group consisting of (meth) acryloyl groups The rubber composition in any one. The rubber composition according to any one of claims 1 to 4 , wherein the (meth) acrylic polymer (D) has a number average molecular weight of 5,000 to 100,000. The (meth) acrylic polymer (D) is composed of a carboxyl group, a hydroxyl group, an ether group, an amide group, an amino group, a hydrolyzable silyl group, an epoxy group, an acid anhydride group, and an active chlorine group in the molecular chain. a rubber composition according to any one of claims 1 to 5, characterized in that it comprises at least one or more functional groups which are more selective in the molecule. The rubber composition according to any one of claims 1 to 6 , wherein the rubber composition is for tires. A pneumatic tire characterized by using the rubber composition according to any one of claims 1 to 7. A pneumatic tire tread, which comprises using a rubber composition according to any one of claims 1 to 7.