WO2017171458A1 - Rubber composition for tire tread - Google Patents

Abstract

The present invention relates to a rubber composition for a tire tread, capable of simultaneously satisfying both grip force (wet/dry) and rotational resistance characteristics by using a silane-modified petroleum resin produced from copolymerization of a petroleum resin-based monomer and a silane-based compound.

Description

Rubber composition for tire tread

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0039458 dated March 31, 2016 and Korean Patent Application No. 10-2017-0039166 dated March 28, 2017. All content disclosed in the literature is included as part of this specification.

The present invention relates to a rubber composition for tire treads that can satisfy both grip force and rotational resistance at the same time.

The tire supports the load of the vehicle, mitigates the impact generated on the road, and delivers the power and braking power of the car engine to the road to maintain the movement of the car. There are a number of characteristics required for a vehicle tire to satisfy, such as durability, wear resistance, rolling resistance, fuel economy, steering stability, ride comfort, braking, vibration, noise, and the like.

Recently, as vehicles are advanced and safety requirements are increased, high performance tires are required to maintain optimal performance on various road surfaces and climates. To meet these demands, tire energy consumption efficiency ratings have been introduced.

The tire energy consumption efficiency rating system measures the rolling resistance (friction force) and wet road braking force of tire products to improve energy consumption efficiency (fuel efficiency) in the vehicle driving stage. It is a scheme to encourage consumers to choose high-efficiency tires, just as they select energy-efficient electric refrigerators.

The tire energy consumption efficiency rating is classified into two types of fuel efficiency (efficiency) and safety. The lower the rolling resistance of the tire, the better the fuel efficiency, and the higher the braking force of the wet road, the higher the safety. .

Fuel efficiency is measured based on rolling resistance (RR) and refers to resistance generated while a round object such as a tire moves in a straight line at a constant speed in a plane. In addition, wet road braking force (Wet Grip) refers to the braking performance, the tire performance related to safety, and as the information on the accident of the vehicle is frequently encountered, the awareness of safety increases, which shows much interest in the braking performance of the vehicle. have.

On the other hand, the rubber composition of the tire tread is made of rubber, fillers and other additives, by changing their composition to adjust the physical properties required for the tire, that is, rotational resistance, durability, grip force and the like.

Rubber, which is the main material of the tire tread rubber composition, deforms and recovers to its original state after a certain time. This is due to its elasticity, which is a property of rubber. Deterioration should be minimized. Thus, the Republic of Korea Patent No. 10-0227566 proposed that the use of carbon black and silica as a reinforcing material can significantly lower the rotational resistance, Republic of Korea Patent No. 10-1572106 to further lower the rotational resistance, silane A method of using vinyltris (2-methoxyethoxy) silane as a compound has been proposed.

 Regarding the improvement of the grip force, Korean Laid-Open Patent No. 2016-0002044 discloses excellent grip performance under high-speed conditions by using a master batch containing styrene-butadiene rubber and pellet type plant resins such as sesame resin, sunflower resin, and coconut resin. And a composition showing wear resistance.

As already mentioned, the grip force is a technique that allows the tire surface to closely adhere to the road surface, and it is advantageous if the tire elasticity is excellent. However, when considering the rolling resistance, the rolling resistance is advantageous as the adhesion to the road surface is lower, so that the rolling resistance and the grip force of the tire are opposite to each other. That is, tires with low rolling resistance may be advantageous in fuel efficiency but may have poor adhesion to the road when the road is wet.

Recently, tire development is progressing in a way to adjust the two at the same time out of the one-dimensional way to increase the rolling resistance or increase the grip force.

For example, Korean Patent Publication No. 2015-0024701 and US Patent No. 8,637,606 apply modified terpene phenolic resins having a high softening point together with silica, thereby improving the compatibility of phenols with synthetic rubbers. It is disclosed that the grip performance on a wet road surface can be improved by reducing the fluidity of the sheet without deteriorating the rolling resistance performance.

In addition, the Republic of Korea Patent No. 10-1591276 Tg is -50 to -40 ℃, the pattern viscosity is 60 to 80 ℃, including 20 to 50 parts by weight of epoxidized natural rubber having an epoxidation degree of 5 to 50 mol%, tires It has been proposed a rubber composition which can improve the wet road braking force of and can improve the durability performance with low rotational resistance performance or fuel economy performance without deterioration of abrasion resistance performance.

Despite these various attempts, there is a need for a technique that has a satisfactory value of both the rolling resistance and the grip force of the tire.

[Preceding technical literature]

[Patent Documents]

Republic of Korea Patent No. 10-0227566 (1999.08.04), rubber tread rubber composition

Republic of Korea Patent No. 10-1572106 (2015.11.20), rubber tread rubber composition and a tire manufactured using the same

Republic of Korea Patent Publication No. 10-2016-0002044 (January 07, 2016), the rubber composition for tire treads and tires manufactured using the same

Republic of Korea Patent Publication No. 10-2015-0024701 (2015.03.09), rubber tread rubber composition

8,637,606 (January 28, 2014), Tires and tread formed from phenol-aromatic-terpene resin

Republic of Korea Patent No. 10-1591276 (January 28, 2016), rubber tread rubber composition and a tire manufactured using the same

In order to solve the above problems, the present inventors pay attention to the properties of carbon black, silica and silane coupling agents used to improve physical properties in the rubber composition for tire tread, inorganic materials such as silica by using a material having high compatibility with Multidisciplinary research was carried out under the idea of increasing the dispersibility of.

As a result, when petroleum resin modified with silane is used as an additive instead of a simple petroleum resin, it is possible to manufacture low-fuel, high-performance tires by improving the compatibility as well as improving the grip properties and rotational resistance as well as the basic physical properties of a tire tread. Confirmed.

Accordingly, an object of the present invention is to improve the grip force and at the same time lower the rising width of the rolling resistance known to the opposite physical properties, low fuel efficiency high performance tire tread that can satisfy the two properties of the grip force and rotation resistance required as a tire at the same time It is to provide a rubber composition.

In order to achieve the above object, the present invention provides a rubber composition for tire treads, comprising a silane-modified petroleum resin copolymerized with a petroleum resin monomer, and a silane compound represented by the following formula (1):

[Formula 1]

CH ₂ = C (R ₁ )-(COO) _x (C _n H _2n ) _y Si (R ₂ ) (R ₃ ) (R ₄ )

(In Formula 1, R ₁ to R ₄ , n, x and y are as described in the specification.)

At this time, the petroleum resin monomer is characterized in that the olefin monomer having at least one ethylenically unsaturated group selected from mixed C5 fraction, mixed C9 fraction and dicyclopentadiene obtained from naphtha cracking.

In addition, the rubber composition for the tire tread is characterized in that it comprises a raw rubber, carbon black, silica, a silane coupling agent, a vulcanizing agent, and a vulcanization accelerator together with the silane-modified petroleum resin.

The rubber composition for tire treads according to the present invention improves the grip force (wet / dry) of the tire, lowers the rising width of the rotational resistance according to the improvement of the grip force, and simultaneously satisfies the two physical properties of the grip force and the rotational resistance required as a tire Low fuel efficiency, high performance tires can enhance product competitiveness.

The present invention improves the dry / wet grip of a tire and at the same time lowers the rise of rotational resistance, which is known to be the opposite of the physical properties, to satisfy the two properties of the tire and the grip force required as a tire. It provides a rubber composition for.

The grip force referred to herein includes both wet grip force and dry grip force. At this time, the wet grip force refers to the grip force on the road surface wetted by snow or rain water, and the dry grip force refers to the grip force on a general road surface state. Good grip means that the tire and the road have high adhesion, which means good braking when cornering or stopping.

The rolling resistance refers to the ratio of the rolling resistance to the load applied to the tire, and in the present invention, the excellent rolling resistance characteristic means that the energy loss between the tire itself or the tire and the road surface is small or the rising width of the rolling resistance is high when the vehicle is driven. It means less.

The grip force and the rotational resistance are opposite to each other. When the grip force is increased, the rotational resistance is also increased to increase fuel economy. As described above, the rubber composition for tire treads according to the present invention must satisfy the contradictory aspect of improving the fuel efficiency by reducing the rotational resistance while securing the braking property by increasing the grip force.

Rubber compositions used in tire treads include raw rubbers, reinforcing agents, silane coupling agents, vulcanizing agents, and vulcanizing accelerators, wherein silica is used together with carbon black as a reinforcing agent to increase rotational resistance and silane coupling to increase grip. Use ring agent. At this time, the rotational resistance and the grip force increase only when the silica and the silane coupling agent are uniformly mixed. In the present invention, the carbon black, the silica and the silane coupling agent have inorganic properties, and Si (for the silica and the silane coupling agent) In consideration of having a high compatibility, that is, by using a silane-modified petroleum resin, the grip force is increased, thereby increasing the rotational resistance, thereby satisfying the grip force and the rotational resistance characteristics at the same time.

Specifically, the silane-modified petroleum resin proposed in the present invention means that the petroleum resin monomer and the silane compound are prepared by copolymerizing with each other.

The repeating unit composed of the petroleum resin monomer increases the hysteresis of the rubber composition for tire treads (energy loss per number of repeated deformations of the tire), thereby converting and absorbing external energy generated during tire braking into thermal energy to increase the grip force of the tire.

In addition, the repeating unit composed of the silane-based compound exhibits high compatibility with carbon black, silica, and a silane coupling agent, an inorganic filler used as a reinforcing agent in the rubber tread rubber composition due to the presence of Si, It is possible to secure the effect of increasing the dispersibility and lowering the rolling resistance obtained by the use of the above composition.

More specifically, the petroleum resin monomer used in the production of the silane-modified petroleum resin proposed in the present invention, specifically, is derived from naphtha cracking and includes at least one ethylenically unsaturated functional group which is a polymerizable functional group in a molecular structure. Preferably, the petroleum resin monomer may be a mixed C5 to C12 fraction, or a diolefin in a liquid phase, which may be put to practical use. Preferably, the mixed C5 fraction, a mixed C9 fraction, or a diolefin may be used.

Mixed C5 fractions include 1-pentene, 2-methyl-2-butene n-pentane, propadiene, dicyclopentadiene, piperylene, isoprene, cyclopentene, 1,3-pentadiene, and the like. Silver styrene, vinyltoluene, indene, alphamethylstyrene and benzene / toluene / xylene (BTX) and the like; diolefins are propadiene, dicyclopentadiene, piperylene, isoprene, cyclopentene, 1 , 3-pentadiene and the like. Preferably, the petroleum resin monomers include diolefins, more preferably dicyclopentadiene.

The silane monomer copolymerized with such a petroleum resin monomer includes an ethylenically unsaturated functional group which is a polymerizable functional group in a molecular structure, and is preferably represented by the following Chemical Formula 1:

[Formula 1]

CH ₂ = C (R ₁ )-(COO) _x (C _n H _2n ) _y Si (R ₂ ) (R ₃ ) (R ₄ )

(In Formula 1, R ₁ is hydrogen or methyl group, R ₂ to R ₄ are the same as or different from each other, hydrogen, C1 to C20 alkyl group, C3 to C12 cycloalkyl group, C1 to C12 alkoxy group, C2 to C12 An acyloxy group, a C6 to C30 aryloxy group, a C5 to C30 araloxy group, or a C1 to C20 amine group,

n is an integer from 1 to 12,

x and y are 0 or 1).

Preferably, R ₁ is hydrogen or a methyl group, R ₂ to R ₄ are the same as or different from each other, an alkyl group of C1 to C6, or an alkoxy group of C1 to C6, n is an integer of 1 to 6, x and y is 0 or 1.

"Alkyl" as used herein means a linear or branched saturated monovalent hydrocarbon moiety of 1 to 20, preferably 1 to 10, more preferably 1 to 6 carbon atoms. The alkyl group may be further substituted by the following substituents as well as unsubstituted. Examples of alkyl groups include methyl, ethyl, propyl, 2-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl, dodecyl, and the like, and additionally substituted with halogen, fluoromethyl, difluoro Chloromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, iodomethyl, bromomethyl and the like.

As used herein, "cycloalkyl" refers to a saturated or unsaturated non-aromatic monovalent monocyclic, bicyclic or tricyclic hydrocarbon moiety of 3 to 12 ring carbons, further defined by the following substituents. Can be substituted. For example, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl, cyclooctyl, decahydronaphthalenyl, adamantyl, norbornyl (ie, bicyclo [2,2, 1] hept-5-enyl) etc. are mentioned.

As used herein, "alkoxy" means a linear or branched saturated monovalent hydrocarbon moiety of 1 to 12, preferably 1 to 10, more preferably 1 to 6 carbon atoms. The alkoxy group may be further substituted by the following substituents as well as unsubstituted. Examples of the alkoxy group are methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentoxy, ethoxy, dodecoxy and the like, and when substituted with halogen, fluoromethoxy, difluoromethoxy, tri Fluoromethoxy, chloromethoxy, dichloromethoxy, trichloromethoxy, iodomethoxy, bromomethoxy and the like.

As used herein, "acyloxy" is a linear or branched hydrocarbon of 1 to 12, preferably 1 to 10 carbon atoms, such as acetoxy, ethanoloxy, propanoloxy, butanoloxy, pentanoloxy, Hexanoloxy, 2,2-dimethylpropanoloxy, 3,3-dimethylbutanoloxy and the like. These may be further substituted by certain substituents described below.

As used herein, "aryloxy" includes the case where oxygen is contained in a monocyclic aryl group or a polycyclic aryl group. An aryl group means an aromatic ring. Specifically, as the aryloxy group, phenoxy, p-tolyloxy, m-tolyloxy, 3,5-dimethyl-phenoxy, 2,4,6-trimethylphenoxy, p-tert-butylphenoxy, 3-biphenyl Oxy, 4-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, 4-methyl-1-naphthyloxy, 5-methyl-2-naphthyloxy, 1-anthryloxy, 2-anthryl Oxy, 9-anthryloxy, 1-phenanthryloxy, 3-phenanthryloxy, 9-phenanthryloxy, and the like, but are not limited thereto.

As used herein, the "amine group" is not particularly limited in number of carbon atoms, but is preferably 1 to 30. Specific examples of the amine group include methylamine group, dimethylamine group, ethylamine group, diethylamine group, phenylamine group, naphthylamine group, biphenylamine group, anthracenylamine group, and 9-methyl-anthracenylamine group. , Diphenylamine group, phenylnaphthylamine group, ditolylamine group, phenyltolylamine group, triphenylamine group and the like, but are not limited thereto.

All compounds or substituents herein may be substituted or unsubstituted unless otherwise specified. Herein, the substituted hydrogen is a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an amino group, a thio group, a methylthio group, an alkoxy group, a nitrile group, an aldehyde group, an epoxy group, an ether group, an ester group, an ester group , Carbonyl group, acetal group, ketone group, alkyl group, perfluoroalkyl group, cycloalkyl group, heterocycloalkyl group, allyl group, benzyl group, aryl group, heteroaryl group, derivatives thereof and combinations thereof Means replaced by one.

Specifically, the silane-based compound of formula 1 is vinyltrimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, triacetoxyvinylsilane, triphenylvinylsilane, tris (2-methoxyethoxy) vinylsilane, 3 -(Trimethoxysilyl) propyl methacrylate, γ- (meth) acryloxypropyl trimethoxysilane and mixtures thereof, and one selected from the group consisting of vinyltrimethoxysilane. .

Silane-modified petroleum resins according to the present invention are prepared by copolymerization of petroleum resin monomers and silane compounds as described above. The copolymerization proceeds by addition reaction between the petroleum resin monomer and the double bond present in the silane compound.

The copolymerization may be used in various ways, it is not particularly limited in the present invention. For example, thermal polymerization, photopolymerization, ion polymerization, and radiation polymerization can be performed, and thermal polymerization can be preferably used.

The thermal polymerization is carried out by adding a petroleum resin monomer and a silane compound to the reactor, and then reacted for 0.5 to 10 hours, preferably 1 to 3 hours by applying heat of 150 to 300 ℃, if necessary, can be applied pressure have. Pressure application is carried out by mounting a separate pressure application device or by thermal polymerization in an autoclave. At this time, the pressure is carried out in the range of 20 to 25bar.

The range of reaction temperature, time and pressure during thermal polymerization is an optimal parameter for obtaining a petroleum resin that can satisfy both rotational resistance and grip force when applied to a rubber tread rubber composition. When the range of the reaction temperature, time and pressure is out of the range, an unreacted substance is present in the final product or the molecular weight of the petroleum resin is lowered. In addition, due to side reactions or excessive increase in molecular weight when thermal polymerization is performed under excessive conditions, it is not easy to secure satisfactory physical properties when applied to the rubber composition for tire tread of the final product.

Along with the thermal polymerization conditions, the content ratio used in thermal polymerization of the petroleum resin monomer and the silane compound should be considered, and they are used in 50 to 95% by weight and 5 to 50% by weight, respectively. The silane-based compound is involved in the softening point and degree of polymerization of the final silane-modified petroleum resin, and these properties decrease as the content thereof increases. Therefore, the silane-based compound is used in the above-mentioned range, preferably 10 to 25% by weight, more preferably 10 to 20% by weight.

In particular, the petroleum resin monomer and the silane-based compound have high reactivity, thereby eliminating the use of a thermal polymerization initiator during thermal polymerization, and a reaction solvent may be used if necessary.

Non-polymerizable solvents may be used as propane, butane, pentane, hexane, octane, decane, dodecane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, dichloro Methane, chloroethane, dichloroethane, chlorobenzene and the like are used, preferably benzene, xylene, toluene, cyclohexane or a mixed solvent thereof can be used. At this time, the reaction solvent may be used by diluting the final concentration of the reactant to 30 to 70% by weight.

The petroleum resin obtained after thermal polymerization is subjected to a general post-treatment process, for example, degassing and concentration to remove unreacted substances, side reaction products and the like to obtain a silane-modified resin to be prepared in the present invention.

The degassing process is a process for separating solid silane-modified petroleum resin, unreacted substances and side reaction products (eg oligomers) at high temperature and, if necessary, under high pressure.

The degassing process is directly related to the yield and softening point of the petroleum resin, and the higher the degassing temperature, the lower the yield and softening point. However, when too low, the purity of the silane-modified petroleum resin is greatly reduced because it is difficult to remove unreacted substances and side reaction products. Therefore, the degassing process should be carried out under the condition that the yield and softening point do not decrease.

Preferably, the present invention is carried out for 1 to 15 minutes in the temperature range of 200 to 280 ℃, preferably 230 to 270 ℃. If degassing is carried out at a temperature below the above, the purity of the silane-modified petroleum resin is lowered as mentioned above. On the contrary, if the degassing is carried out at the above temperature, the yield and the softening point are decreased, so Since adhesive force and cohesion force) fall, it uses suitably within the said range.

The silane-modified petroleum resin prepared through the above steps is a resin having a softening point of 70 to 150 ° C., preferably 90 to 130 ° C., measured according to STM E28, and a number average molecular weight (Mn) of 500 to 5000. resin having a range of g / mol. In particular, the softening point and the molecular weight is a parameter that directly affects the grip force and the rolling resistance, and the high softening point and the molecular weight means that the hardness after curing is increased, which means that the rolling resistance may be lowered. In addition, the softening point and low molecular weight means that the resin has flexibility, which means that the adhesion to the road surface may be increased and thus the grip force may be increased. In the present invention, it is possible to secure the optimum effect when having the above range.

In addition, the silane-modified petroleum resin according to the present invention has a proton content of silanes determined by ¹ H-NMR of at least 1.7%, a proton content of silanes of at least 7%, and is analyzed by X-ray fluorescence spectroscopy. It is resin which Si weight fraction which is the weight ratio which a silicon (Si) element occupies among all the obtained elements is at least 0.3 wt%.

As described above, the silane-modified petroleum resin according to the present invention is a copolymer of an olefin-based compound represented by dicyclopentadiene and a silane-based compound, and includes a silane compound together with the adhesiveness of a conventional petroleum resin for tire treads. The compatibility with the carbon black, silica, and silane coupling agents used in the rubber composition can be enhanced to further increase the tire physical properties (particularly, rotational resistance and grip force).

Such silane-modified petroleum resin is used in 1 to 30 parts by weight, preferably 5 to 15 parts by weight based on 100 parts by weight of the raw rubber. If the content is less than the above range, the effect of improving the rotational resistance and the grip force cannot be expected simultaneously. On the contrary, if the content exceeds the above range, the workability and the processability of reducing the viscosity of the rubber composition have to be redesigned to reduce the viscosity of the rubber composition. It may be lowered, which may cause deterioration of physical properties such as tensile strength and hardness of the final manufactured tire, so it is suitably used within the above range.

In Experimental Example 3 of the present invention, the rubber composition for tire treads was prepared including the composition described above, and the grip force and rotational resistance thereof were measured.

The grip force is involved in the brake braking property and is indicated by a loss factor (Tan δ) measured at a frequency of 10 to 100 Hz, 0 ° C, and 25 ° C by a dynamic viscoelastic test, and the larger the loss factor, the better the brake braking property is. The excellent dry grip property means that the loss coefficient (Tan δ) measured at a frequency of 10 to 100 Hz and around 25 ° C. by the dynamic viscoelastic test of the rubber composition is large. By the dynamic viscoelastic test, the loss coefficient (Tan δ) measured at a frequency of 10 to 100 Hz and around 0 ° C is large.

Rotational resistance is shown by the loss coefficient (Tan delta) measured by the dynamic viscoelastic test of the rubber composition for tire treads about 10-100 Hz, 70 degreeC, and a smaller said loss coefficient improves rolling resistance characteristic. The excellent rotational resistance characteristic means that the loss coefficient (Tan δ) measured at a frequency of 10 to 100 Hz and around 70 ° C by a dynamic viscoelastic test of the rubber composition for automobile tread is small.

The four measured values, Tg, Tan δ (0 ° C.), Tan δ (25 ° C.) and Tan δ (70 ° C.) are moving in the same trend. Preferably the rotational resistance (R / R, Tan δ 70 ° C.) or wet grip force (Tan δ 0 ° C.) should be improved while Tg is maintained at the same or similar level. Ideally, the direction in which the rotational resistance is lowered and the wet grip force is higher is preferable. However, since the rotational resistance and the wet grip force are complementary to each other, it is not easy to improve both of these properties. Therefore, it is most ideal to increase the wet grip force while the rotational resistance is substantially maintained or at least deteriorated.

According to Experimental Example 2 of the present invention, in the case of using the silane-modified petroleum resin according to the present invention, a loss factor was measured at 11 Hz while Tg was kept the same, and compared with rubber (Comparative Example 1) not using the same. As a result, the dry grip force improved up to 128%, the wet grip force increased by 133%, and the rotational resistance increased within -16%. This can be seen as a similar level compared to the terpene phenol resin (Comparative Example 2), which is currently used in the industry for the purpose of improving grip. Through this, even if the value of the grip force is increased when applying the product of the present invention it was possible to minimize the rising value of the rotational resistance.

As already mentioned, the rubber composition for tire treads according to the present invention includes raw rubber, reinforcing agent, silane coupling agent, vulcanizing agent, and vulcanization accelerator as essential compositions in addition to the silane-modified petroleum resin.

The raw material rubber is not particularly limited as long as it has an olefinic double bond (carbon-carbon double bond), and natural rubber, synthetic rubber, or a mixture thereof can be used. For example, the raw rubber may be natural rubber, butadiene rubber, nitrile rubber, silicone rubber, isoprene rubber, styrene-butadiene rubber (SBR), isoprene-butadiene rubber, styrene-isoprene-butadiene rubber, acrylonitrile-butadiene rubber ( NBR), ethylene-propylene-diene rubber, halogenated butyl rubber, halogenated isoprene rubber, halogenated isobutylene copolymer, chloroprene rubber, butyl rubber and halogenated isobutylene-p-methylstyrene rubber It is preferable.

As the reinforcing agent, carbon black and silica are used.

Carbon black obtains effects such as improvement of abrasion resistance, improvement of rotational resistance characteristics, prevention of cracking and cracking (ultraviolet rays deterioration) by ultraviolet rays. The carbon black usable in the present invention is not particularly limited, and any carbon black may be used as long as it is commonly used in the field of tire treads. For example, as the carbon black, carbon black such as farnes black, acetylene black, thermal black, channel black and graphite may be used. In addition, physical properties such as particle diameter, pore volume, specific surface area, etc. of carbon black are not particularly limited, and various carbon blacks used in the rubber industry, for example, SAF, ISAF, HAF, FEF, GPF, SRF (all of which are abbreviations for carbon black classified in the ASTM specification D-1765-82a of the United States) and the like can be suitably used.

Such carbon black is preferably contained 5 to 50 parts by weight, preferably 50 to 65 parts by weight based on 100 parts by weight of the raw rubber. The carbon black is an essential element for rubber compounding as a reinforcing filler. If the content is less than the above range, the effect of reinforcing is inferior. On the contrary, if the carbon black exceeds the above range, dispersion is difficult.

In addition, silica can be used without particular limitation what is used as a rubber reinforcing agent in the tire tread field, for example, dry method white carbon, wet method white carbon, synthetic silicate-based white carbon, colloidal silica, precipitated silica and the like. . Although the specific surface area of silica does not have a restriction | limiting in particular, Usually, the range of 40-600 m <2> / g, Preferably it is 70-300 m <2> / g, The thing of 10-1000 nm can be used for a primary particle diameter. These may be used independently or may be used in combination of 2 or more type.

Such silica is preferably included in 30 to 80 parts by weight, preferably 50 to 65 parts by weight based on 100 parts by weight of the raw rubber. If the content is less than the above range, the rotational resistance is high and the fuel efficiency is lowered. On the contrary, if the content exceeds the above range, the grip force may be lowered. Therefore, it is suitably used within the above range.

As the reinforcing agent, in addition to the carbon black and silica, powders of minerals such as clay and talc, carbonates such as magnesium carbonate and calcium carbonate, alumina hydrates such as aluminum hydroxide and the like can be used.

Silane coupling agents are used to compound the silica.

Examples of the silane coupling agent that can be used include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris (β-methoxy-ethoxy) silane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, 3 -Chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis (3- (triethoxysilyl) propyl) disulfide , Bis (3-triethoxysilylpropyl) trisulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilyl Propyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2- Mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl Trasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropyl Benzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxy Methylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide, and the like. It is used individually or in mixture of 2 or more types, Preferably bis (3- (triethoxysilyl) propyl) tetrasulfide is used.

The use amount of the silane coupling agent depends on the content of silica, and preferably 5 to 20 parts by weight based on 100 parts by weight of the raw rubber. If the content is less than the above range, it is difficult to uniformly mix silica, which may lower the physical properties of the tire tread. On the contrary, if the content exceeds the above range, the gelation of rubber may occur during the production of the tire tread. Use it appropriately.

The crosslinking agent can be used without particular limitation what is normally used for crosslinking of the rubber, and can be appropriately selected according to the rubber component and the isobutylene polymer. As a crosslinking agent, For example, sulfur crosslinking agents, such as a sulfur, a morpholine disulfide, and an alkylphenol disulfide; Cyclohexanone peroxide, methyl acetoacetate peroxide, tert-butylperoxy isobutylate, tert-butylperoxybenzoate, benzoyl peroxide, lauroyl peroxide, dicumyl peroxide, di-tert-butyl peroxide And organic peroxide crosslinking agents such as 1,3-bis (tert-butylperoxyisopropyl) benzene and the like.

The crosslinking agent is used in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the raw rubber, and if the content is less than the above range, the crosslinking is insufficient, making it difficult to manufacture tires having desired physical properties (eg wear resistance), and vice versa. In this case, too, due to excessive crosslinking, the physical properties of the tire (eg, elasticity) are lowered, so it is appropriately used within the above range.

The rubber composition for automobile treads according to the present invention together with the crosslinking agent includes a vulcanization accelerator and a vulcanization aid. It does not specifically limit as a vulcanization accelerator and a vulcanization adjuvant, According to the rubber component, isobutylene-type polymer, and crosslinking agent which a rubber composition contains, it can select suitably and can use. In addition, "vulcanization" represents the bridge | crosslinking through at least one sulfur atom.

As a vulcanization accelerator, For example, Thiuram type accelerators, such as tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, and tetraethyl thiuram disulfide; Thiazole type accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide; Sulfenamide-based accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide and N-oxydiethylene-2-benzothiazolylsulfenamide; Guanidine-based accelerators such as diphenylguanidine and diorthotriguanidine; aldehyde-amine accelerators such as n-butylaldehyde-aniline condensate and butylaldehyde-monobutylamine condensate; Aldehyde-ammonia-based accelerators such as hexamethylenetetramine; Thiourea type accelerators, such as thiocarbanilide, etc. are mentioned. When mix | blending these vulcanization accelerators, you may use individually by 1 type or in combination of 2 or more types.

The content of such a vulcanization accelerator is preferably used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the raw rubber, in view of improving physical properties.

Examples of the vulcanization aid include metal oxides such as zinc oxide (zinc) and magnesium oxide; Metal hydroxides such as calcium hydroxide; Metal carbonates such as zinc carbonate and basic zinc carbonate; Fatty acids such as stearic acid and oleic acid; Aliphatic metal salts such as zinc stearate and magnesium stearate; Amines such as din-butylamine and dicyclohexylamine; Ethylene dimethacrylate, diallyl phthalate, N, N-m-phenylenedimaleimide, triallyl isocyanurate, trimethylolpropane trimethacrylate, and the like. When mix | blending these vulcanization adjuvant, you may use individually by 1 type or may use it in combination of 2 or more type.

The content of such vulcanization aid is preferably used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the raw rubber, in view of improving physical properties.

In addition, the rubber composition according to the present invention may also be used as one or two or more of various additives used in the field of the rubber industry, for example, an anti-aging agent, a vulcanization retardant, an annealing agent, a process oil, a plasticizer, etc. You may contain it. It is preferable that the compounding quantity of these additives is 0.1-10 weight part with respect to 100 weight part of rubber components.

The rubber composition for automobile treads comprising the composition as described above is made into a tire by a known method.

As an example, the rubber composition according to the present invention can be prepared by kneading each of the above components using a kneading machine such as a plastomill, a Banbury mixer, a roll, an internal mixer, or the like. Specifically, among the above components, it is preferable to knead components other than the crosslinking agent and the vulcanization accelerator and further knead the crosslinking agent and the vulcanization accelerator to the obtained kneaded product after that.

The rubber composition produced by the above method can be used as a material constituting a tread portion (and a cap portion including the tread portion) in contact with the road surface. In view of the production method, an uncrosslinked molded body for a tire is produced by extrusion processing in accordance with the shape of the tire (specifically, the shape of the tread) in which the rubber composition is to be formed, and molding in a conventional manner on a tire molding machine. A tire tread can be manufactured by heat-pressing this uncrosslinked molded object for tires in a vulcanizer, for example, and a tire tread and other parts can be manufactured, and a target tire can be manufactured.

The tires thus produced are excellent in mechanical properties (elasticity, wear resistance, hardness, tensile strength, modulus, etc.) to be used as tires. In particular, the grip (wet / dry) is high, driving stability and brake braking of the vehicle is excellent, and the rotational resistance is low, it is possible to implement a low fuel consumption of the vehicle.

Therefore, the rubber composition of this invention is suitable as a rubber composition for obtaining the tread of tires, such as a low fuel consumption tire and a high performance tire.

Hereinafter, preferred examples and comparative examples of the present invention will be described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

Production Example  One: Silane  denaturalization Petroleum resin  1 manufacturer

312.5 g of dicyclopentadiene (DCPD, Kolon Industries Co., Ltd., purity 80%) (corresponding to 250 g of reactant in consideration of purity) and vinyltrimethoxysilane (TMVS.reagent grade, product of Aldrichtk, purity 99.99%) 62.5 g The total amount of the two components is Hysol (Kolon Industries Co., Ltd., a process product mainly composed of non-polymeric naphthenic materials) as a solvent (corresponding to 20% by weight of the total amount with the DCPD reactant). Was weighed in an amount of 50% by weight, and introduced into a 1L autoclave. After adding the raw materials, the reactor was fastened and replaced with nitrogen to remove unnecessary reaction such as reaction with oxygen at high temperature.

When the temperature of the reactor was raised to 275 ° C. and the reaction temperature was reached, the reaction time was measured and reacted for 1 hour (in the reaction conditions, the reactor internal pressure was 20 to 25 bar). When the reaction was completed, it was cooled to room temperature. After cooling to 30 ° C. or lower, the internal pressure was depressurized, and the reactor was opened to obtain a polymer.

Since the polymer contained a solvent and an unreacted material in addition to the polymerized material, the polymer was removed. Specifically, the total amount of the polymer was put in a 1 L glass four-neck kettle, and vacuum was obtained at room temperature. The degree of vacuum was maintained at 10 torr, and when the vacuum was caught, the temperature was raised to 240 ° C with stirring. When the temperature reached 240 ° C., the concentration time began to be measured and maintained for 10 minutes. When the concentration was completed, the vacuum was released in that state to recover the molten resin powder therein.

Production Example  2: Silane  denaturalization Petroleum resin  2 manufacturing

A silane-modified petroleum resin was prepared in the same manner as in Preparation Example 1, except that degassing was performed at 260 ° C.

Production Example  3: Silane  denaturalization Petroleum resin  3 manufacturing

A silane-modified petroleum resin was prepared in the same manner as in Preparation Example 2 except that degassing was performed for 20 minutes.

Production Example  4: terpene phenol-modified Petroleum resin  Produce

In accordance with US Pat. No. 8,637,606, terpene phenol-modified petroleum resin was prepared.

Experimental Example  1: property evaluation

The physical properties of the silane / terpene phenol-modified petroleum resins prepared in Preparation Examples 1 to 4 were measured, and the results are shown in Table 1 below.

	How to measure	Preparation Example 1	Preparation Example 2	Preparation Example 3	Preparation Example 4
Softening point	ASTM E 28	100 ℃	120 ℃	130 ℃	115 ℃
Mn (g / mol)	Gel Permeation Chromatography (Hewlett-Packard Company, model name HP-1100)	455	649	662	808
Mw (g / mol)		689	966	1002	1093
Mz (g / mol)		1256	1478	1624	2345

Example  1 to 3, Comparative example  1 and 2: tires Tread  Rubber composition

A rubber composition for tire treads was prepared using the silane or terpene phenol-modified petroleum resin prepared above.

A tire tread rubber composition was prepared in the composition of Table 2 below, and rubber specimens were prepared for physical property measurement.

After adding the composition shown in Table 2 to the short-barrier mixer, the compounding operation and vulcanization at 160 ℃ 20 minutes to prepare a test rubber specimen. At this time, Comparative Example 1 means a composition (Blank) not using a silane-modified petroleum resin, Comparative Example 2 means a composition using a petroleum resin prepared according to US Patent No. 8,637,606.

Composition (parts by weight)		Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
Raw material rubber	ESBR 1 )	100	100	100	100	100
Petroleum resin	Preparation Example 1	5	-	-	-	-
	Preparation Example 2	-	5	-	-	-
	Preparation Example 3	-	-	5	-	-
	Preparation Example 4	-	-	-	-	5
Reinforcement	Carbon Black 2 )	60	60	60	60	60
	Silica 3 )	60	60	60	60	60
Silane coupling agent	TESPT 4 )	10	10	10	10	10
Vulcanizer	Sulfur 5 )	1.5	1.5	1.5	1.5	1.5
Vulcanization accelerator	ZnO 6 )	3	3	3	3	3
additive	Stearic acid 7 )	2	2	2	2	2
	DPG 8 )	One	One	One	One	One
	TBBS 9 )	1.5	1.5	1.5	1.5	1.5
Note 1) ESBR (SBR-1502), manufactured by KKPC, 2) CarbonN-330, manufactured by OEC, 3) SilicaZ-155, manufactured by Evonik, 4) TESPT; Bis (3- (triethoxysilyl) propyl) tetrasulfide, X-50S, manufactured by Evonik, 5) Sulfur, manufactured by Miwon chem, 6) ZnO, manufactured by Kemai chem, 7) manufactured by Stearic acid, Kemai chem , 8) DPG: Diphenyl guanidine, manufactured by Miwon chem, 9) TBBS; n-cyclohexyl benzothiazyl-2-sulfamide, manufactured by Miwon chem

Experimental Example  2: measuring mechanical properties

The physical properties of the rubber specimens prepared in Examples and Comparative Examples were measured, and the results are shown in Table 3 below.

Properties		Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
UTM Measurement 1 )	50% modulus (kgf / cm 2 )	21.95	21.93	20.45	23.70	21.01
	100% modulus kgf / cm 2 )	30.33	30.47	30.85	30.96	28.17
	300% modulus (kgf / cm 2 )	66.03	68.04	67.95	66.31	61.38
	Tensile Strength (break, kgf / cm 2 )	222.72	219.08	219.57	222.69	219.03
	Elongation at break (%)	1163.94	1073.4	1068.54	1147.35	1222.52
Hardness 2)	Shore A	85	86	86	86	84
Rubber rheometer 3 )	T min	5.75	5.49	5.89	8.64	6.52
	T max	29.22	30.22	30.91	37.33	31.3
	Ts2	1:43	1:52	1:50	1:08	1:26
	Tc10	1:55	2:04	2:03	1:27	1:40
	Tc50	4:12	4:11	4:00	3:29	4:09
	Tc90	7:24	7:14	6:56	6:25	7:30
Abrasion Resistance 4 )	Initial weight (g)	3.8312	3.8449	3.8559	3.9289	3.8808
	1 time (g)	3.6724	3.6629	3.6728	3.6473	3.6954
	2 times (g)	3.5140	3.4901	3.5246	3.4174	3.5317
	loss	4.31%	4.72%	4.03%	6.30%	4.43%
1) UTM Properties: Model: UTM-Shimadzu AG-1S (Load cell: PFG-5kN), 2) Hardness: Model: Shore Hardness Tester (Shore-A type), 3) Rubber Rheometer: ASTM D 5289- 95 (2001), 4) Abrasion Resistance: ASTM D 2228

Referring to Table 3, the rubber compositions of Examples 1 to 3 showed the same mechanical properties (modulus, tensile strength, elongation, hardness, etc.) compared to Comparative Examples 1 and 2.

Rheometer results, measured with rubber rheometers, are parameters related to the rate of cure and the behavior of the rubber composition during process application, and are related to processability in tire manufacturing. At this time, if the value (T _min , T _max ) is too high or low, it is not easy to apply to the existing process, which means that a new process design is required. The results of T _min , T _max , Ts2 (scorch time), Tc2 (time to 2% curing), Tc90 (time to 90% curing), etc. of Examples 1 to 3 shown in Table 3 above It can be seen that it corresponds to a specification that can be easily applied to an existing process.

Abrasion resistance is a wear resistance by contact, which is a value that is considered when using a rubber product such as a tire in a dynamic state, and the rubber composition of Examples 1 to 3 exhibits a loss of about 4.7% or less. It can be seen that excellent.

From these results, it can be seen that the silane-modified petroleum resin proposed in the present invention can satisfactorily satisfy the physical properties required as a tire without affecting the workability even when added during the manufacture of a tire.

Experimental Example  3: Grip Rotational resistance Dynamic machinery  Analyzer (DMA) Measurement

The loss coefficient (Tan δ) and glass transition temperature (Tg) related to grip force and rolling resistance were measured at 11 Hz by using Dynamic Mechanical Analysis (Model: TA-DMA Q800). 1 is shown. At this time, higher values of Tan δ @ 0 ° C and Tan δ @ 25 ° C mean better grip force, and lower values of Tan δ @ 70 ° C mean better rotation resistance.

	Tanδ			Tg (℃)
	0 ℃	25 ℃	70 ℃
Example 1	0.1778	0.1265	0.1466	-34.2
	125%	123%	83%
Example 2	0.1899	0.1313	0.1448	-33.1
	133%	128%	84%
Example 3	0.1875	0.131	0.1488	-33.9
	131%	128%	82%
Comparative Example 1	0.1428	0.1026	0.1221	-34.7
	100%	100%	100%
Comparative Example 2	0.1717	0.12	0.1441	-33.4
	120%	117%	85%

As shown in Table 4, looking at the value of Tan δ (0 ℃), which is a loss factor associated with the wet grip force of the rubber composition of Examples 1 to 3 and Tan δ (25 ℃) associated with the dry grip force, this is a comparative example Dry grip force up to 128%, wet grip force is increased by 133% compared to 1, it can be seen that when using the silane-modified petroleum resin according to the present invention can improve the wet / dry grip force.

In the case of the numerical value of Tan δ (70 ° C.), which is related to the rotational resistance, the rubber compositions of Examples 1 to 3 rose with the improvement of the grip force, but the terpene phenol resins which are commonly used in the industry and in general (compare Compared to Example 2, it can be seen that it is possible to effectively reduce the increase in rotational resistance due to the increased grip force by using the silane-modified petroleum resin.

The numerical values of Tan δ associated with the rotational resistance and the grip force presented in Table 4 are reliable data as a result of comparing the Tg values. The peak value of Tan δ is related to Tg. To compare Tan δ related to rolling resistance and grip force, the Tg value should be compared at almost the same level. It can be seen that the compositions of Examples and Comparative Examples have a Tg value in a nearly similar range.

From these results, it can be seen that the rubber composition for tire treads including the silane-modified petroleum resin according to the present invention secures an effect of simultaneously satisfying grip force and rotational resistance.

The rubber composition for tire treads according to the present invention is preferably applicable to the production of tire products with low fuel efficiency and high performance.

Claims (11)

1. A rubber composition for tire treads comprising a petroleum resin-based monomer and a silane-modified petroleum resin copolymerized with a silane-based compound represented by Formula 1 below:

   [Formula 1]

   CH ₂ = C (R ₁ )-(COO) _x (C _n H _2n ) _y Si (R ₂ ) (R ₃ ) (R ₄ )

   (In Formula 1, R ₁ is hydrogen or methyl group, R ₂ to R ₄ are the same as or different from each other, hydrogen, C1 to C20 alkyl group, C3 to C12 cycloalkyl group, C1 to C12 alkoxy group, C2 to C12 An acyloxy group, a C6 to C30 aryloxy group, a C5 to C30 araloxy group, or a C1 to C20 amine group,

   n is an integer from 1 to 12,

   x and y are 0 or 1).
2. The method of claim 1,

   R ₁ is hydrogen or a methyl group, R ₂ to R ₄ are the same as or different from each other, an alkyl group of C1 to C6 or an alkoxy group of C1 to C6, n is an integer of 1 to 6, x and y are 0 or Rubber composition for a tire tread for 1 person.
3. The method of claim 1,

   The petroleum resin monomer is a rubber composition for tire treads which is one selected from the group consisting of mixed C5 fractions, mixed C9 fractions, dicyclopentadienes and mixtures thereof obtained from naphtha cracking.
4. The method of claim 1,

   The silane compound is vinyl trimethyl silane, vinyl trimethoxy silane, vinyl triethoxy silane, triacetoxy vinyl silane, triphenyl vinyl silane, tris (2-methoxy ethoxy) vinyl silane, 3- (trimethoxy A rubber composition for a tire tread, which is one selected from the group consisting of silyl) propyl methacrylate, γ- (meth) acryloxypropyl trimethoxysilane, and mixtures thereof.
5. The method of claim 1,

   The silane-modified petroleum resin has a softening point of 70 to 150 ℃, the number average molecular weight (Mn) is 500 to 5000 g / mol rubber composition for the tire tread.
6. The method of claim 1,

   The silane-modified petroleum resin is a rubber composition for tire tread copolymerized with 50 to 95% by weight of petroleum resin monomer and 5 to 50% by weight of silane compound.
7. The method of claim 1,

   The copolymer is a rubber tread rubber composition is carried out by a thermal polymerization method.
8. The method of claim 7, wherein

   The thermal polymerization is a rubber composition for tire treads carried out at a pressure of 20 to 25 bar at 150 to 300 ℃.
9. The method of claim 1,

   The silane-modified petroleum resin is a tire tread rubber composition is contained in 1 to 30 parts by weight based on 100 parts by weight of the raw rubber in the rubber tread rubber composition.
10. The method of claim 1,

    The tire tread rubber composition comprises a raw rubber, carbon black, silica, a silane coupling agent, a vulcanizing agent, and a vulcanizing accelerator rubber composition for a tire tread.
11. The method of claim 10,

    The rubber composition for tire tread is 5 to 50 parts by weight of carbon black, 30 to 80 parts by weight of silica, 5 to 20 parts by weight of silane coupling agent, 0.1 to 5 parts by weight of vulcanizing agent, and a vulcanization accelerator based on 100 parts by weight of raw rubber. Rubber composition for a tire tread comprising 0.1 to 10 parts by weight.