RUBBER COMPOSITION

Abstract

According to the rubber composition of the present invention comprising 0.1 to 10 parts by mass of -9 fatty acid amide and 0.1 to 100 parts by mass of an adhesive resin based on 100 parts by mass of a rubber component, the rubber composition being excellent in processability, mold release characteristics and abrasion resistance can be provided.

Claims

1. A rubber composition for a tire comprising: 0.1 to 10 parts by mass of -9 fatty acid amide and 0.1 to 100 parts by mass of an adhesive resin based on 100 parts by mass of a rubber component, wherein the rubber composition excludes a rubber composition for low temperature resistant tires, which is obtained from the following raw materials by weight: 60 to 80 parts by mass of a regenerated rubber, 15 to 25 parts by mass of an attapulgite, 10 to 15 parts by mass of a dolomite powder, 6 to 8 parts by mass of a rosin, 10 to 15 parts by mass of a silicone rubber, 3 to 5 parts by mass of an epoxy soybean oil, 2 to 4 parts by mass of a butyl acrylate, 0.15 to 0.25 parts by mass of a potassium persulfate, 1 to 2 parts by mass of an erucamide, 1 to 2 parts by mass of a zinc stearate, 0.15 to 0.25 parts by mass of a sodium lauryl sulfate, 1 to 2 parts by mass of a sulfur, and 5 to 10 parts by mass of a composite auxiliary agent; wherein the composite auxiliary agent is made of the following raw materials by weight: 30 to 40 parts by mass of a tea seed oil, 3 to 5 parts by mass of a turpentine, 1 to 2 parts by mass of a glycerol, 10 to 15 parts by mass of an acetyl tributyl citrate, 0.5 to 1 parts by mass of a phytic acid, 1 to 2 parts by mass of a sorbitan monostearate, and 1 to 2 parts by mass of a nano titanium dioxide.

2. The rubber composition for a tire of claim 1, comprising the -9 fatty acid amide in the form of a molten mixture comprising the -9 fatty acid amide and calcium stearate.

3. The rubber composition for a tire of claim 2, wherein the molten mixture is a molten mixture comprising 25 to 75% by mass of -9 fatty acid amide and 25 to 75% by mass of calcium stearate.

4. The rubber composition for a tire of claim 1, comprising: an adhesive resin having a softening point of 130 C. or lower and at least one of a process oil and a liquid polymer, wherein a total content of the adhesive resin having a softening point of 130 C. or lower, the process oil and the liquid polymer is not less than 20 parts by mass.

5. The rubber composition for a tire of claim 1, comprising not less than 9 parts by mass of a process oil.

6. The rubber composition for a tire of claim 1, comprising 40 to 150 by mass of a silica.

7. A tire comprising a tire member composed of the rubber composition for a tire of claim 1.

Description

EXAMPLE

[0063] The present invention will be described based on Examples, but the present invention is not limited thereto only.

[0064] A variety of chemicals used in Examples and Comparative Examples will be explained below.

Oleamide: ALFLOW E-10 (transparent melting point: 74 C.) manufactured by NOF CORPORATION
Calcium stearate: CALCIUM STEARATE G (transparent melting point: 154 C.) manufactured by NOF CORPORATION
Calcium 12-hydroxystearate: Calcium Castor Stearate (transparent melting point: 152 C.) manufactured by NOF CORPORATION
Stearamide: ALFLOW S-10 (transparent melting point: 103 C.) manufactured by NOF CORPORATION
Erucamide: ALFLOW P-10 (transparent melting point: 82 C.) manufactured by NOF CORPORATION
SBR1: N9548 manufactured by ZEON Corporation (oil extended amount: 37.5 parts, styrene content: 35% by mass, vinyl content: 18%,
Tg: 40 C., weight-average molecular weight: 1,090,000)
SBR2: NS612 manufactured by ZEON Corporation (non-oil extended, styrene content: 15% by mass, vinyl content: 30%, Tg: -65 C., weight-average molecular weight: 780,000)
BR: CB24 manufactured by Lanxess K.K. (high-cis BR synthesized using an Nd-based catalyst, Tg: -110 C.)
Carbon black: SHOBLACK N220 available from Cabot Japan K.K. (N.sub.2SA: 114 m.sup.2/g)
Silica 1: ULTRASIL VN3 manufactured by Evonik Degussa GmbH (N.sub.2SA: 175 m.sup.2/g)
Silica 2: Z115Gr available from Rhodia Japan, Ltd. (N.sub.2SA: 115 m.sup.2/g)
Silane coupling agent 1: Si75 (bis(3-triethoxysilylpropyl)disulfide) manufactured by Evonik Degussa GmbH
Aluminum hydroxide: APYRAL200SM (average particle size: 0.6 m, N.sub.2SA: 15 m.sup.2/g) manufactured by Sumitomo Chemical Co., Ltd.
Adhesive resin 1: Koreshin available from BASF Japan (phenolic resin, softening point: 145 C., Tg: 98 C.)
Adhesive resin 2: YS POLYSTER T160 (terpene phenol resin, softening point: 160 C., Tg: 100 C.) manufactured by Yasuhara Chemical Co., Ltd.
Adhesive Resin 3: YS RESIN TO125 (aromatic terpene resin, softening point: 125 C., Tg: 64 C.) manufactured by Yasuhara Chemical Co., Ltd.
Adhesive resin 4: Sylvatraxx4401 (-methylstyrene resin, softening point: 85 C., Tg: 43 C.) manufactured by Arizona Chemical Company, LLC
Adhesive Resin 5: NOVARES C10 (liquid coumarone-indene resin, softening point: 10 C., Tg: 30 C.) manufactured by Ruetgers Chemicals
Non-adhesive resin 1: 40MS available from Struktol GmH (styrene-ethylene-propylene copolymer resin, softening point: 102 C., Tg: 62 C.)
Non-adhesive resin 2: PR12686 (softening point: 93 C., Tg: 51 C.) manufactured by Sumitomo Bakelite Co., Ltd.
Non-adhesive Resin 3: MODIPER A1100 (polyethylene-polystyrene resin, softening point: 111 C., Tg: 85 C.) manufactured by NOF CORPORATION.
Non-adhesive resin 4: M-890A (DCPD petroleum resin, softening point: 115 C., Tg: 89 C.) manufactured by MARUZEN PETROCHEMICAL CO., LTD.
Process oil: Diana Process Oil manufactured by Idemitsu Kosan Co., Ltd.
Caster oil: Industrial castor oil No. 1 manufactured by HOKOKU CORPORATION
Liquid polymer: L-SBR820 (Liquid SBR, Mw: 10,000) manufactured by KURARAY CO., LTD.
Molten mixtures 1 to 11: each of molten mixtures prepared in accordance with Preparation of Molten mixtures mentioned later
Stearic acid: Ginrei R manufactured by Toho Zinc Co., Ltd.
Zinc sterate: Zinc stearate manufactured by NOF CORPORATION
Mold release agent 1: EF44 (fatty acid zinc, transparent melting point: 103 C.) available from Struktol GmH
Mold release agent 2: WB16 (a mixture of fatty acid calcium salt, fatty acid monoethanol amide and an ester of fatty acid monoethanol amide, transparent melting point: 101 C.) available from Struktol GmH
Mold release agent 3: Aflux37 (transparent melting point: 100 C.) manufactured by Rhein Chemie Corporation
Antioxidant 1: ANTIGENE 6C (6PPD, N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Company, Limited.
Antioxidant 2: NOCRAC 224 (TMQ, 2,2,4-trim ehtyl-1,2-dihydro quinolene polymer) manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO., LTD.
Wax: Ozoace 355 manufactured by Nippon Seiro Co., Ltd.
Zinc oxide: Zinc Oxide Class 2 manufactured by Mitsui Mining & Smelting Co., Ltd.
Sulfur: HK-200-5 (oil content: 5% by mass) manufactured by Hosoi Chemical Industry Co., Ltd.
Crosslinking resin: TACKIROL 201 (alkylphenol-formaldehyde resin) manufactured by Taoka Chemical Co., Ltd.
Vulcanization accelerator 1: Nocceler NS-G (TBBS, N-tert-butyl-2-benzothiazolesulfenamide) manufactured by Ou chi Shinko Chemical Industrial Co., Ltd.
Vulcanization accelerator 2: Nocceler D (DPG, 1,3-diphenylguanidine) manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.

Preparation of Molten Mixtures

[0065] A flask containing compounds shown in Table 1 was dipped into a silicon oil bath, followed by stirring with an electronic stirrer while heating up until the both compounds were melted, and then an obtained molten product was taken out, cooled and pulverized in a mortar to obtain uniform molten mixtures 1 to 11. Table 1 also shows transparent melting points of the respective molten mixtures. These transparent melting points are values measured according to Test methods for melting point and melting range of chemical products of JIS K 0064: 1992.

TABLE-US-00001 TABLE 1 Compounding amount Molten mixture (% by mass) 1 2 3 4 5 6 7 8 9 10 11 Oleamide 10 25 50 75 100 50 Calcium stearate 100 90 75 50 25 50 50 Calcium 12-hydroxystearate 50 Stearamide 100 50 Erucamide 100 50 Transparent melting point ( C.) 154 138 120 88 80 74 126 103 119 82 96

Examples and Comparative Examples

[0066] According to compounding formulations shown in Tables 2 to 6, chemicals except sulfur and a vulcanization accelerator were kneaded with a 1.7-liter sealed Banbury mixer at a discharge temperature of 160 C. for 5 minutes to obtain a kneaded product. Further, the obtained kneaded product was kneaded again with the 1.7-liter sealed Banbury mixer at a discharge temperature of 150 C. for four minutes (re-milling). Subsequently by using a biaxial open roll, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and a mixture was kneaded for four minutes until a temperature of the mixture became 105 C. to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was subjected to press-vulcanization at 170 C. for 12 minutes to produce a test rubber composition.

[0067] Each of the unvulcanized rubber compositions obtained according to compounding formulations shown in Tables 2 to 6 was extrusion-molded into a form of a tread using an extruder with an extrusion nozzle having a specific shape, and an extrudate was laminated with other tire members to form an unvulcanized tire, followed by press-vulcanization at 170 C. for 12 minutes to produce a test tire. The following evaluations were made using the obtained unvulcanized rubber compositions, test rubber compositions and test tires. The results of the evaluations are shown in Tables 2 to 6.

Index of Viscosity

[0068] A Mooney viscosity (ML.sub.1+4) of each of the unvulcanized rubber compositions after the re-milling was determined under the temperature condition of 130 C. according to JIS K 6300-1 Unvulcanized rubberPhysical propertiesPart. 1: Method for measuring viscosity and scorch time using a Mooney viscometer. The result is shown by an index, assuming an inverse number of a Mooney viscosity of Comparative Example 1 to be 100. As the index is larger, the Mooney viscosity is lower. A performance target value is 100 or more.

Index of Mold Release Characteristics

[0069] A degree of adhesion of the unvulcanized rubber composition onto a rotor metal and a mixer inner wall after kneading with a 1.7-liter Banbury mixer was evaluated visually and with a peeling time. The result is shown by an index, assuming release characteristics of Comparative Example 1 to be 100. As the index is larger, the release characteristics is lower. A performance target value is 105 or more.

Index of Abrasion Resistance

[0070] Each of the test tires was loaded on four wheels of a test vehicle (a domestic FF vehicle, displacement: 2,000 cc) and after in-vehicle running of 8,000 km on a dry asphalt road surface, a depth of the groove of each tire tread portion was measured. A traveling distance in which a groove depth of a tire was decreased by 1 mm was calculated. Assuming that an abrasion resistance index of Comparative Example 1 is 100, a result of each compounding formulation is indicated by an index with the following equation (abrasion resistance index). The larger the abrasion resistance index is, the more excellent the abrasion resistance is. A performance target value is 100 or more.

Abrasion resistance index=(Traveling distance when a tire groove depth is decreased by 1 mm)/(Traveling distance of Comparative Example 1 when a tire groove depth is decreased by 1 mm)100

Index of Wet Grip Performance

[0071] Each of the test tires was loaded on four wheels of a test vehicle (a domestic FF vehicle, displacement: 2,000 cc). A braking distance after braking at an initial speed of 100 km/hr on a wet asphalt road was measured. The wet grip performance was indicated with an index in accordance with the following equation, assuming the wet grip performance of Comparative Example 1 to be 100. The larger the index of the wet grip performance is, the more excellent the wet grip performance is. A lowest target value for performance is not less than 100, and 105 or more is more preferable.

(Index of wet grip performance)=(Braking distance of Comparative Example 1)/(Braking distance of each formulation)100

TABLE-US-00002 TABLE 2 Compounding amount Comparative Example (part by mass) 1 2 3 4 5 6 7 8 9 10 11 SBR 1 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 SBR 2 30 30 30 30 30 30 30 30 30 30 30 BR 40 40 40 40 40 40 40 40 40 40 40 Carbon black 5 5 5 5 5 5 5 5 5 5 5 Silica 1 110 110 110 110 110 110 110 110 110 110 110 Silica 2 Silane coupling agent 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 Aluminum hydroxide Adhesive resin 1 20 20 Adhesive resin 2 Adhesive resin 3 20 29 Adhesive resin 4 10 10 10 10 10 10 10 10 10 Adhesive resin 5 Process oil 39 39 39 39 39 39 39 9 39 39 Liquid polymer Molten mixture 1 3 Molten mixture 2 Molten mixture 3 Molten mixture 4 Molten mixture 5 Molten mixture 6 Molten mixture 7 Molten mixture 8 3 Molten mixture 9 3 Molten mixture 10 3 Molten mixture 11 Stearic acid 2 2 2 2 5 2 2 2 2 2 2 Zinc stearate 3 Mold releasing agent 1 3 Mold releasing agent 2 3 3 3 Mold releasing agent 3 3 Antioxidant 1 2 2 2 2 2 2 2 2 2 2 2 Antioxidant 2 1 1 1 1 1 1 1 1 1 1 1 Wax 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 2 2 2 2 2 2 2 2 2 2 2 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Vulcanization accelerator 2 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Evaluation Index of viscosity 100 100 91 89 94 104 100 111 116 104 114 Index of mold release characteristics 100 100 94 100 108 100 112 95 97 110 94 Index of abrasion resistance 100 101 102 88 94 94 95 110 106 96 106 Index of wet grip performance 100 100 99 85 92 98 98 124 115 94 104

TABLE-US-00003 TABLE 3 Compounding amount Example (part by mass) 1 2 3 4 5 6 7 8 9 10 11 SBR 1 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 41.25 SBR 2 30 30 30 30 30 30 30 30 30 30 30 BR 40 40 40 40 40 40 40 40 40 40 40 Carbon black 5 5 5 5 5 5 5 5 5 5 5 Silica 1 110 110 110 110 110 110 110 110 110 110 110 Silica 2 Silane coupling agent 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8 Aluminum hydroxide Adhesive resin 1 Adhesive resin 2 Adhesive resin 3 10 Adhesive resin 4 10 10 10 10 10 10 10 10 10 10 Adhesive resin 5 20 Process oil 39 39 39 39 39 39 39 39 36 19 39 Liquid polymer Molten mixture 1 Molten mixture 2 3 Molten mixture 3 3 Molten mixture 4 3 1 6 10 3 Molten mixture 5 3 Molten mixture 6 3 Molten mixture 7 3 Molten mixture 8 Molten mixture 9 Molten mixture 10 Molten mixture 11 3 Stearic acid 2 3 2 2 2 2 2 2 2 2 2 Zinc stearate Mold releasing agent 1 Mold releasing agent 2 Mold releasing agent 3 Antioxidant 1 2 2 2 2 2 2 2 2 2 2 2 Antioxidant 2 1 1 1 1 1 1 1 1 1 1 1 Wax 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 2 2 2 2 2 2 2 2 2 2 2 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Vulcanization accelerator 2 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Evaluation Index of viscosity 110 101 107 110 114 107 108 106 105 100 115 Index of mold release characteristics 113 107 108 112 106 107 107 105 120 117 117 Index of abrasion resistance 109 102 104 106 106 106 101 109 101 100 115 Index of wet grip performance 107 102 103 104 104 104 102 107 106 100 115

TABLE-US-00004 TABLE 4 Compounding amount Example (part by mass) 12 13 14 15 16 17 SBR 1 41.25 41.25 41.25 41.25 41.25 41.25 SBR 2 30 30 30 30 30 30 BR 40 40 40 40 40 40 Carbon black 5 5 5 15 5 50 Silica 1 110 110 110 107 70 Silica 2 110 Silane coupling agent 8.8 8.8 8.8 8.8 8.8 8.8 Aluminum hydroxide 10 50 Adhesive resin 1 20 20 20 Adhesive resin 2 10 Adhesive resin 3 20 29 20 Adhesive resin 4 10 10 Adhesive resin 5 Process oil 39 9 45 39 29 Liquid polymer 40 Molten mixture 1 Molten mixture 2 Molten mixture 3 Molten mixture 4 3 3 3 3 3 3 Molten mixture 5 Molten mixture 6 Molten mixture 7 Molten mixture 8 Molten mixture 9 Molten mixture 10 Molten mixture 11 Stearic acid 2 2 2 2 2 2 Zinc stearate Mold releasing agent 1 Mold releasing agent 2 Mold releasing agent 3 Antioxidant 1 2 2 2 2 2 2 Antioxidant 2 1 1 1 1 1 1 Wax 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 2 2 2 2 2 2 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1 1.3 1.3 1.3 1.3 1.3 1.3 Vulcanization accelerator 2 2.5 2.5 2.5 2.5 2.5 2.5 Evaluation Index of viscosity 118 125 130 108 108 100 Index of mold release characteristics 117 106 110 108 113 105 Index of abrasion resistance 115 125 122 111 105 100 Index of wet grip performance 110 130 120 113 119 140

TABLE-US-00005 TABLE 5 Compounding amount Comparative Example (part by mass) 12 13 14 15 16 17 18 SBR 1 41.25 41.25 41.25 41.25 41.25 41.25 41.25 SBR 2 30 30 30 30 30 30 30 BR 40 40 40 40 40 40 40 Carbon black 5 5 5 5 5 5 5 Silica 1 110 110 110 110 110 110 110 Silica 2 Silane coupling agent 8.8 8.8 8.8 8.8 8.8 8.8 8.8 Aluminum hydroxide Adhesive resin 1 Adhesive resin 2 Adhesive resin 3 Adhesive resin 4 Adhesive resin 5 Process oil 39 39 39 39 39 39 39 Liquid polymer Molten mixture 1 Molten mixture 2 3 Molten mixture 3 3 Molten mixture 4 3 Molten mixture 5 3 Molten mixture 6 3 Molten mixture 7 3 Molten mixture 8 Molten mixture 9 Molten mixture 10 Molten mixture 11 3 Stearic acid 2 3 2 2 2 2 2 Zinc stearate Mold releasing agent 1 Mold releasing agent 2 Mold releasing agent 3 Antioxidant 1 2 2 2 2 2 2 2 Antioxidant 2 1 1 1 1 1 1 1 Wax 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Zinc oxide 2 2 2 2 2 2 2 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Vulcanization accelerator 1 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Vulcanization accelerator 2 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Evaluation Index of viscosity 115 106 112 114 119 113 113 Index of mold release characteristics 123 117 118 121 115 116 117 Index of abrasion resistance 112 105 107 109 109 109 103 Index of wet grip performance 92 90 89 88 90 88 87

TABLE-US-00006 TABLE 6 Comparative Example 19 20 21 22 Compounding amount (part by mass) SBR 1 41.25 41.25 41.25 41.25 SBR2 30 30 30 30 BR 40 40 40 40 Carbon black 5 5 5 5 Silica 1 110 110 110 110 Silica 2 Silane coupling agent 8.8 8.8 8.8 8.8 Aluminum hydroxide Adhesive resin 1 10 Adhesive resin 2 10 Adhesive resin 3 10 Adhesive resin 4 10 Adhesive resin 5 39 39 39 39 Process oil Liquid polymer Molten mixture 1 Molten mixture 2 Molten mixture 3 3 3 3 3 Molten mixture 4 Molten mixture 5 Molten mixture 6 Molten mixture 7 Molten mixture 8 Molten mixture 9 Molten mixture 10 Molten mixture 11 Stearic acid 2 3 2 2 Zinc stearate Mold releasing agent 1 Mold releasing agent 2 Mold releasing agent 3 Antioxidant 1 2 2 2 2 Antioxidant 2 1 1 1 1 Wax 1.5 1.5 1.5 1.5 Zinc oxide 2 2 2 2 Sulfur 1.5 1.5 1.5 1.5 Vulcanization accelerator 1 1.3 1.3 1.3 1.3 Vulcanization accelerator 2 2.5 2.5 2.5 2.5 Evaluation Index of viscosity 114 111 111 110 Index of mold release 135 130 132 129 characteristics Index of abrasion resistance 111 104 100 108 Index of wet grip performance 88 93 89 90

[0072] From the results shown in Tables 2 to 6, it is seen that the rubber composition of the present invention comprising predetermined amounts of -9 fatty acid amide and an adhesive resin is excellent in processability, mold release characteristics, abrasion resistance and wet grip performance.