KR100869904B1 - Tire tread rubber composition improved abrasion property - Google Patents

Abstract

A rubber composition for a tire tread is provided to improve abrasion resistance and rotation resistance of a tire thread compound by applying a silane-grafted ultrahigh molecular weight polyethylene. A rubber composition for a tire tread comprises 100 parts by weight of a base rubber; 50~90 parts by weight of at least one of carbon black and silica as a filler; and 1~20 parts by weight of silane-grafted ultrahigh molecular weight polyethylene. The silane-grafted ultrahigh molecular weight polyethylene is prepared by surface-treating a ultrahigh molecular weight polyethylene which is an ethylene homopolymer having the average molecular weight of 500 or more or an ethylene-alphaolefin copolymer, with at least one functional group selected from OH, alkoxy radical, aldehyde group, carbonyl radical, carboxyl, amine radical and nitro group; adding silane and peroxide to the surface-treated ultrahigh molecular weight polyethylene and reacting it.

Description

Tire Tread Rubber Composition Improved Abrasion Property}

The present invention relates to a rubber composition for tire treads, and more particularly, to tire treads having improved wear resistance and rolling resistance performance of a tire compound by including silane-grafted ultra high molecular weight polyethylene in a rubber composition for tire treads. It relates to a rubber composition.

In the prior art, Korean Patent Publication No. 2003-0080025 attempts to improve wear performance by using ultra high molecular weight polyethylene, and Korean Patent Publication No. 2004-0024850 and Korean Patent Publication No. 2005-0053425 are nonpolar. The ultra-high molecular weight polyethylene was applied by modifying the surface to show improved abrasion performance compared to general ultra-high molecular weight polyethylene. However, non-polar polyethylene has affinity with rubber and silica, so that the compoundability is poor due to its dispersibility and bonding ability. In comparison with the wear performance of the raw material of the ultra high molecular weight polyethylene, it is difficult to show an effect that the wear performance is greatly improved when the tire is applied.

The present invention is to provide a rubber composition for tire treads by improving the wear resistance and rolling resistance of the tread compound of the tire, by applying the silane-grafted ultra high molecular weight polyethylene in order to solve the above problems. .

The rubber composition for tire treads according to the present invention contains 50 to 90 parts by weight of at least one of carbon black and silica as a filler, and 1 to 20 parts by weight of silane-grafted ultra high molecular weight polyethylene, based on 100 parts by weight of the raw material rubber. It is characterized by.

The raw material rubber used in the present invention is not particularly limited to the kind thereof, and natural rubber, synthetic rubber or mixed rubber thereof is used. Preferably, butadiene rubber (BR), styrene butadiene rubber, butyl rubber and epichlorohydrin are used. Drined rubber, nitrile rubber, hydrogenated nitrile rubber, brominated polyisobutylisoprene-co-paramethylstyrene (BIMS), urethane rubber, fluorine rubber, silicone rubber, styrene ethylene butadiene styrene copolymer rubber (SEBS), ethylene propylene rubber , Ethylene propylene diene rubber (EPDM), hypalon rubber, chloroprene rubber, ethylene vinyl acetate rubber, acrylic rubber can be used alone or in combination of two or more thereof.

  The type of filler used in the present invention is not particularly limited, and at least one of carbon black and silica is preferably used, and 50 to 90 parts by weight is preferably used as a total amount. It is not preferable because it is not preferable, and if it exceeds 90 parts by weight, the amount of filler that cannot be bonded with rubber increases, which is not preferable.

The silane-grafted ultra high molecular weight polyethylene used in the present invention is used to increase the bonding strength with silica and to improve processability and dispersibility simultaneously.

The silane-grafted ultra high molecular weight polyethylene is treated with a functional group to increase the bonding strength with silica to the ethylene homopolymer or the ethylene-alpha olefin copolymer ultra high molecular weight polyethylene having a weight average molecular weight of 5 million or more and to improve wear performance and fairness. As illustrated in the following reaction scheme, the ultrahigh molecular weight polyethylene surface-treated with the functional group may be prepared by adding silane and a peroxide to react with heat.

As the functional group used for the surface treatment of the ultra high molecular weight polyethylene, one or more selected from hydroxy group, alkoxy group, aldehyde group, carbonyl group, carboxyl group, amine group and nitro group which have affinity with silica may be used. The repeating unit of the treated ultra high molecular weight polyethylene can be represented by the following structural formula.

The silane used in the production of the silane-grafted ultra high molecular weight polyethylene is a vinyl-based silane having good interconnection with polyethylene, and is not particularly limited in its type, and is vinyl triethoxy silane (VTEOS) and vinyl trimeth. Vinyltrimethoxyethoxy silane (VTMOEOS), vinylbenzylaminoethylaminopropyltrimethoxysilane ([2 (vinylbenzylamino) -ethyl] -3-aminopropyltrimethoxy silane), dimethylvinmethoxymethoxysilane (DMVMOS; dimethylvinylmethoxy silane), dimethyl At least one selected from vinyl ethoxysilane (DMVEOS), methylvinyldimethoxy silane (methyvinyldimethoxy silane) and methylvinyldimethoxy silane (methyvinyldimethoxy silane) may be used. The peroxide is preferably dicumyl peroxide. However, the peroxide is not particularly limited to dibenzoyl peroxide and bis-peroxide-2,5-dimethyl-2,5-di (t-butyl). Peroxide) -hexane, t-dibutyl cumyl peroxide, di-t-butyl peroxide, di (t-butyl peroxide) diisopropyl benzene can be used 1 or more types.

The silane-grafted ultra high molecular weight polyethylene is preferably used 1 to 20 parts by weight, but less than 1 part by weight does not exhibit abrasion performance is not preferable, if exceeding 20 parts by weight because the hardness is sharply increased to cause cracks Not desirable

In addition to the above-mentioned components, the rubber composition of the present invention includes additives that are commonly used in rubber treads, such as silane coupling agents, aromatic oils, antioxidants, zinc oxide, stearic acid, sulfur, accelerators, activators, and the like. An additive can be mix | blended in the normal usage range.

The rubber composition for tire treads of the present invention includes an silane-grafted ultra high molecular weight polyethylene, and thus has an effect of improving abrasion resistance and rolling resistance.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, these examples do not limit the scope of the present invention.

After the tire tread rubber compositions of Examples and Comparative Examples were prepared according to the composition of Table 1, rubber specimens were prepared from the respective rubber compositions, vulcanized at 160 ° C., and then the physical properties thereof were measured according to ASTM standards. Table 2 shows.

Table 1

                                                     (Unit: weight part)

division Comparative Example 1 Example 1 Example 2 Example 3 Styrene Butadiene Rubber 100 100 100 100 Silica 70 70 70 70 UHMW-PE ^{1 )} 5 0 0 0 Silane grafted UHMW-PE ^{2 )} 0 5 10 20 Silane coupling agent ^{3 )} 5.6 5.6 5.6 5.6 Aromatic Oil 37.5 37.5 37.5 37.5 Antioxidant ^{4 )} 2 2 2 2 Zinc oxide 3 3 3 3 Stearic acid 2 2 2 2 sulfur 2 2 2 2 Accelerators ^{5 )} 2 2 2 2 Activator ^{6 )} 0.5 0.5 0.5 0.5

Note 1) Ultra high molecular weight polyethylene: weight average molecular weight is more than 5 million

2) The ultra-high molecular weight polyethylene of 1) is grafted with vinyltrimethoxysilane.

3) TESPT (bis- (3-triethoxysilylpropyl) tetrasulfane)

4) TMDQ (polymerized 2,2,4-trimethyl-1,2-dihydroquinoline)

5) CZ (N-cyclohexyl-2-benzothiazolesulfenamide)

6) DPG (diphenyl guanidine)

TABLE 2

                                                         (Unit: relative index)

 division Comparative Example 1 Example 1 Example 2 Example 3  Properties Hardness 100 104 108 115 300% modulus 100 110 117 127 The tensile strength 100 94 95 98 Elongation 100 97 95 92 Wear resistance DIN wear ^{1 )} 100 115 120 135 Rolling resistance performance 70 ℃ tanδ ²⁾ 100 91 86 80

Note 1) The higher the wear index, the more favorable the value.

2) The lower the rolling resistance, the more favorable the value.

As shown in Table 2, it can be seen that the rubber composition of the embodiment is excellent in wear resistance and rotation resistance performance.

Claims (3)

A rubber composition for tire treads, comprising 50 to 90 parts by weight of at least one of carbon black and silica and 1 to 20 parts by weight of silane-grafted ultra high molecular weight polyethylene, based on 100 parts by weight of the raw material rubber. The silane-grafted ultra high molecular weight polyethylene according to claim 1 is a hydroxy group, an alkoxy group, an aldehyde group, a carbonyl group, a carboxyl group, an amine as a functional group in an ultra high molecular weight polyethylene which is an ethylene homopolymer or an ethylene-alpha olefin copolymer having a weight average molecular weight of 5 million or more. A rubber composition for tire treads, which is prepared by adding silane and a peroxide to a super high molecular weight polyethylene surface-treated with at least one functional group selected from a group and a nitro group. 3. The rubber composition for tire tread according to claim 2, wherein the silane in the silane-grafted ultra high molecular weight polyethylene is vinyl silane.