JP2009001758A - Method for manufacturing rubber composition for use in tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a method for manufacturing a rubber composition for use in a tire, which can reconcile low rolling resistance and abrasion resistance to a higher degree than before; the rubber composition manufactured by using the method; and the tire manufactured by using the rubber composition. <P>SOLUTION: The method for manufacturing the rubber composition for use in a tire is achieved by kneading: a diene rubber (A); a diene rubber (B) identical to or different from the diene rubber (A); a reinforcing filler (C); and a crosslinking agent (D), wherein the method comprises: a step of obtaining a master batch by adding the whole of the filler (C) to the diene rubber (A); and a step of kneading the master batch obtained with the diene rubber (B) and the crosslinking agent (D). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a rubber composition for a tire, a rubber composition produced by the production method, and a tire using the rubber composition. More specifically, the present invention is highly compatible with low rolling resistance and wear resistance. The present invention relates to a method for producing a rubber composition for a tire, a rubber composition produced by the production method, and a tire using the rubber composition.

  In order to improve the wear resistance of a pneumatic tire, for example, carbon black that imparts high reinforcement and excellent wear resistance is widely used as a reinforcing filler for rubber. Further, in order to improve the wear resistance of the pneumatic tire, it is conceivable to increase the filling amount of carbon black or to use carbon black having a smaller particle diameter. However, in either case, there is a problem that hysteresis loss due to carbon black increases and rolling resistance increases. That is, it is generally known that the low rolling resistance and wear resistance of a pneumatic tire are in a mutually contradictory relationship.

  On the other hand, hydrous silicic acid is known as a filler that achieves both low rolling resistance and wear resistance. However, the rubber composition blended with hydrous silicic acid has a problem in that the storage elastic modulus is smaller than that of the rubber composition blended with carbon black having the same specific surface area, so that the grip performance is inferior.

In order to solve the above-described problems, several methods for preparing various master batches have been proposed in the production of a tire rubber composition. For example, Patent Document 1 reports that a masterbatch can be obtained by adding a part or all of a crosslinking agent to butadiene rubber, thereby making it possible to achieve both low rolling resistance and high wear resistance. Yes. Patent Documents 2 and 3 report that low rolling resistance and wear resistance can be improved by preparing a silica masterbatch. Furthermore, Patent Documents 3 to 5 report that a master batch of natural rubber or modified natural rubber is prepared in order to greatly improve low loss, wear resistance, fracture characteristics, and the like.
JP 2003-147124 A JP 2005-179436 A JP 2006-265400 A JP 2006-143879 A JP 2006-143881 A JP 2006-213878 A JP 2006-213879 A JP 2006-219618 A

  By adopting the conventional masterbatch method as described above, the above-mentioned problems associated with the blending of carbon black and hydrous silicic acid have been solved to some extent, but today, it has a higher degree of rolling resistance and wear resistance. There is a demand for a method for producing a rubber composition for a tire that can be made compatible.

  Accordingly, an object of the present invention is to provide a method for producing a rubber composition for a tire capable of achieving both higher rolling resistance and wear resistance than ever before, a rubber composition produced by this production method, The object is to provide a tire using this rubber composition.

  As a result of diligent studies to solve the above problems, the present inventors have produced a rubber composition using a diene rubber masterbatch to which a reinforcing filler has been added in advance, rather than by the conventional method. It has been found that low rolling resistance and wear resistance can be achieved at a higher level, and the present invention has been completed.

That is, the manufacturing method of the rubber composition for tires of the present invention includes a diene rubber (A), a diene rubber (B) that is the same as or different from the (A) diene rubber, and a reinforcing filler (C ) And a crosslinking agent (D), when producing a rubber composition for tires,
The step of adding the reinforcing filler (C) to the diene rubber (A) to obtain a master batch, the diene rubber (B) and the cross-linking agent (D) in the obtained master batch And a step of kneading.

  Further, the present invention relates to a rubber composition for tires obtained by the above production method.

  Furthermore, the present invention relates to a tire characterized by having a tread composed of the tire rubber composition.

  According to the method for producing a rubber composition for a tire of the present invention, both low rolling resistance and wear resistance of a tire can be achieved at a higher level than ever before.

  The method for producing a rubber composition for a tire according to the present invention includes a diene rubber (A), a diene rubber (B) that is the same as or different from the (A) diene rubber, and a reinforcing filler (C). In manufacturing a rubber composition for a tire by kneading a crosslinking agent (D), first, a master batch is prepared by adding all of the reinforcing filler (C) to the diene rubber (A). To do. Next, the diene rubber (B) and the crosslinking agent (D) are kneaded into the obtained master batch. This makes it possible to obtain a low-loss rubber composition while maintaining fracture characteristics and the like as compared with the conventional method, and to achieve both higher rolling resistance and wear resistance than ever before. Can do.

  Here, the weight average molecular weight of the diene rubber (A) is preferably the same as or higher than the weight average molecular weight of the diene rubber (B), more preferably 1 to 5 times. Thereby, it becomes possible to obtain a desired effect more favorably.

  Diene rubbers that can be used as the diene rubber (A) or (B) include styrene-butadiene rubber (SBR), isoprene synthetic rubber (IR), acrylonitrile-butadiene rubber (NBR), and isobutylene-isoprene rubber (IIR). And chloroprene rubber (CR). These rubbers may be used alone or in combination of two or more.

  As the reinforcing filler (C), for example, carbon black, silica, magnesium hydroxide, magnesium oxide, titanium oxide, aluminum hydroxide, clay, alumina, talc, calcium carbonate, which are conventionally used in tire rubber compositions, are used. And inorganic fillers such as magnesium carbonate. Of these, carbon black, which has a high rubber reinforcing effect, is preferred. As such carbon black, those usually used in the rubber industry can be used. For example, various grades of carbon black such as SAF, HAF, ISAF, FEF, and GPF can be used. These reinforcing fillers may be used alone or in combination of two or more.

  The crosslinking agent (D) is a concept that includes a vulcanizing agent and a vulcanization accelerator, and vulcanizes containing sulfur such as sulfur, sulfur chloride compounds, and organic sulfur compounds conventionally used in rubber compositions for tires. Agents, inorganic vulcanizing agents, oximes, nitroso compounds, polyamines, organic peroxides and the like. Examples of the vulcanization accelerator include thiazole compounds, sulfenamide compounds, thiourea compounds, thiuram compounds, guanidine compounds, aldehyde-amine compounds, aldehyde-ammonia compounds, and the like.

  In the present invention, the blending ratio of the diene rubber (A) and the diene rubber (B) in the rubber component is preferably 30 to 70 to 70 to 30 in terms of mass ratio. When the proportion of the diene rubber (A) in 100 parts by mass of the total rubber component is less than 30 parts by mass, sufficient breaking strength cannot be obtained, while when it exceeds 70 parts by mass, sufficient low loss is obtained. I can't.

  Moreover, the compounding amount of the reinforcing filler (C) is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the rubber component. If the blending amount is less than 10 parts by mass, the breaking strength tends to decrease. On the other hand, if it exceeds 200 parts by mass, sufficient low loss cannot be obtained.

  In addition, the compounding quantity of a crosslinking agent (D) can be made into the range applied to the normal rubber compound for tires.

  In the method for producing a tire rubber composition of the present invention, various compounding agents usually used in the rubber industry, for example, anti-aging agent, scorch preventing agent, zinc white, softening, within a range not impairing the object of the present invention. An agent, stearic acid, an ozone deterioration preventing agent and the like can be appropriately blended.

  The master batch according to the present invention can be prepared, for example, by kneading using a usual processing apparatus such as a Banbury mixer, a roll, or a kneader. Moreover, also when kneading this masterbatch, a diene rubber (B), and a crosslinking agent (D), it can knead | mix using the apparatus similar to the case of preparation of a masterbatch.

  By applying the rubber composition for a tire of the present invention obtained by the method of the present invention to a tire tread, it is possible to achieve both higher rolling resistance and wear resistance than the conventional method. The tire of the present invention can be produced by applying the tire rubber composition of the present invention to a tread rubber according to a usual method, and the tire production method itself is not limited at all.

Hereinafter, the present invention will be specifically described based on examples.
According to the composition shown in Table 1 below, a master batch was prepared by kneading at 110 ° C. for 3.5 minutes using a Banbury mixer. Next, with or without using the two kinds of master batches obtained, kneading at 110 ° C. for 3.5 minutes using a Banbury mixer according to the blending contents shown in Table 2 below, and various test rubber compositions Was prepared.

(1) Low loss property Viscoelasticity measuring device [manufactured by Rheometrics Co., Ltd.] is used for vulcanized rubber obtained by vulcanizing various test rubber compositions at 145 ° C for 33 minutes, temperature 50 ° C, strain 10% The loss tangent (tan δ) was measured at a frequency of 15 Hz, and each of Comparative Examples 1, 2, and 3 corresponding to Examples 1, 2, 3, and 4 was indicated as an index. It shows that it is excellent in low-loss property, so that a numerical value is small.

(2) Abrasion resistance The rupture strength at room temperature of a vulcanized rubber obtained by vulcanizing various test rubber compositions at 145 ° C for 33 minutes was measured using a ring tensile abrasion tester. Each example corresponding to 100 of each comparative example was indicated as an index. The larger the index value, the better the fracture characteristics.

ＳＢＲ１：スチレンブタジエンゴムＪＳＲ製♯１５００
ＳＢＲ２：スチレンブタジエンゴムＪＳＲ製♯１７１２（♯１５００の高分子量タイプ）
老化防止剤１：ワックス
老化防止剤２：Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−Ｐ−フェニレンジアミン

SBR1: Styrene butadiene rubber JSR # 1500
SBR2: Styrene butadiene rubber JSR # 1712 (# 1500 high molecular weight type)
Anti-aging agent 1: Wax anti-aging agent 2: N- (1,3-dimethylbutyl) -N′-phenyl-P-phenylenediamine

老化防止剤１：ワックス
老化防止剤２：Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−Ｐ−フェニレンジアミン
加硫促進剤１：１，３−ジフェニルグアジニン
加硫促進剤２：ジベンゾチアジルジスルフィド
加硫促進剤３：Ｎ−ｔ−ブチル−２−ベンゾチアゾリルスルフェンアミド

Anti-aging agent 1: Wax anti-aging agent 2: N- (1,3-dimethylbutyl) -N′-phenyl-P-phenylenediamine vulcanization accelerator 1: 1,3-diphenylguanidine vulcanization accelerator 2: Dibenzothiazyl disulfide vulcanization accelerator 3: Nt-butyl-2-benzothiazolylsulfenamide

  As is apparent from the evaluation results of the characteristics shown in Table 2, the rubber compositions of the examples produced according to the production method of the present invention are superior in both breaking strength and low loss performance to the comparative examples. I understand.

Claims (4)

Kneading a diene rubber (A), a diene rubber (B) that is the same as or different from the (A) diene rubber, a reinforcing filler (C), and a crosslinking agent (D) In producing a tire rubber composition by
A step of adding a total of the reinforcing filler (C) to the diene rubber (A) to obtain a master batch, and the diene rubber (B) and the crosslinking agent (D) added to the obtained master batch. A method of producing a rubber composition for tires.   The production method according to claim 1, wherein the weight average molecular weight of the diene rubber (A) is the same as or higher than the weight average molecular weight of the diene rubber (B).   A rubber composition obtained by the production method according to claim 1.   A tire comprising a tread made of the rubber composition for a tire according to claim 3.