BR102013023963A2 - tread tire comprising functionalized elastomer and pretreated silica - Google Patents

Abstract

tread tire comprising functionalized elastomer and pretreated silica. The invention relates to a tread tire of a rubber composition containing a functionalized elastomer and prehydrophobized precipitated silica reinforcement.

Description

Field of the Invention The invention relates to a tread tire of a rubber composition containing a functionalized elastomer having reactive functional groups with precipitated silica and the use of a rubberized tire. prehydrophobized precipitated silica. ;

Background of the Invention Rubber compositions for the components of various articles of manufacture, including tires, conventionally contain at least one diene-based elastomer, wherein the rubber composition may be reinforced with reinforcement, such as, for example, at least one of carbon black and precipitated silica, namely an amorphous synthetic silica containing hydroxyl groups on its surface, e.g. Precipitated silica is recognized to be hydrophilic in nature, which promotes charge-charge interaction (eg, the interaction between precipitated silica particle-precipitated particle) within the rubber composition and tends to resist interaction. charge-polymer (interaction between precipitated silica-diene-elastomer) within the rubber composition, thereby causing dispersion of the precipitated silica particles within the rubber composition. Such a phenomenon is well known to those having skill in such technique. ; ; The hydrophilic precipitated silica is conventionally coupled to the diene-based elastomer (s) in the rubber composition by the use of a silica coupler or silica coupling agent having a portion, such a dome, e.g. alkoxysilane component reactive with hydroxyl groups (e.g. silanol groups) on precipitated silica and a different portion such as, for example, a sulfur-containing component which is, or becomes, interactive with the diene-based elastomer (s) in the rubber composition. Such coupling of precipitated silica to promote reinforcement of a rubber composition is well known to those having; skill in such a technique. The reduced charge-charge interaction is promoted by pre-hydrophobizing the hydrophilic precipitated silica by pretreatment of the precipitated silica prior to its addition to the rubber composition with at least one of alkylsilane, alkoxysilane and the formerly silica coupling agent. containing an alkoxysilane to react with the hydroxyl groups on the precipitated silica. A part of the hydroxyl groups on the precipitated silica is therefore pre-forced with the alkylsilane groups, which will not couple to or bind to a diene-based polymer. Where the pretreatment also contains a silica coupling agent, the pretreated precipitated silica may interact directly with the diene-based elastomer (s) via the coupling agent contained on the precipitated silica without adding a silica coupling agent to; rubber composition itself. The use of such pre-treated or pre-hydrophobized precipitated silica to promote the best charge-polymer interaction within a rubber composition is well known to those having skill in such a technique. The improved charge-polymer interaction may also be promoted by the use of a functionalized diene-based elastomer containing reactive functional groups with hydroxyl groups on the precipitated silica. In this mode, functional groups on the elastomer may be reacted with hydroxyl groups on precipitated silica, thereby promoting their coupling with the diene-based functionalized elastomer (s) in the composition. Rubber So one. Added silica coupling agent may or may not be used to assist in coupling the precipitated silica to the diene-based elastomer (s) in the rubber composition.

Such pre-treated precipitated silica having been pretreated with a silica coupling agent is readily considered to be used to promote the charge-polymer interaction in a rubber composition containing a group functionalized diene elastomer. reactive functions with the hydroxyl groups on the pretreated precipitated silica.

However, it is also carefully considered that a portion of the hydroxyl groups of the pretreated precipitated silica have been pre-stressed by reaction with the silica coupling agent and also the hydrophobizing alkylsilane groups. Therefore, functional groups on the functionalized diene elastomer in the rubber composition will compete with the few remaining free hydroxyl groups on the precipitated silica, which is considered to significantly alter or reduce the ability of the functionalized polymer to interact effectively with the surface of the rubber. pre-treated silica and effectively reduce the coupling density of the silica in such a rubber composition, which contains both the pre-treated silica and the functionalized diene-based polymers.

Accordingly, this invention relates to a rubber composition containing a functionalized elastomer having functional groups intended to react with the hydroxyl groups contained on the precipitated silica reinforcement, to assist in coupling the precipitated silica with the elastomer and thereby to promote reinforcement of the elastomer with the precipitated silica, where its available hydroxyl groups have been significantly reduced or reduced by pre-hydrophobing (pretreatment) the precipitated silica with a silica coupling agent which may include an alkylsilyl or alkoxysilane which are considered to be reactive with hydroxyl groups on the precipitated silica. .

Therefore, the invention particularly relates to rubber compositions containing such functionalized elastomer and precipitated silica reinforcement which has been prehydrophobized prior to addition to the rubber composition. It is important to appreciate that the precipitated silica is typically hydrophilic in nature and thus does not mix efficiently with the diene-based elastomers and diene elastomer-containing rubber compositions. Such hydrophilic precipitated silica particles generally favor joint agglomeration by mutual attraction between their particles within the rubber composition, which promotes charge-to-charge interaction rather than conrelastomeric charge interaction, which thereby gives a mixture hydrophilic precipitated silica with the rubber composition. Such a phenomenon is well known to those having skill in the technique.

Therefore, there is an inherent motivation; to hydrophobize (e.g., pre-hydrophobize) such hydrophilic precipitated silica to make it more compatible with the elastomer (s) and thus promote interaction of carcass with elastomer and thereby mixing more efficient with dieno-based elastomers. Hydrophilic precipitated silica may be hydrophobized by treatment with various alkoxysilane-containing compounds, for example, silica coupling agents which react with hydroxyl groups on the precipitated silica in situ within such rubber compositions. The compounds; alkoxysilane-based non-silica coupling agents may also be used for this purpose.

Alternatively, the precipitated silica! Hydrophilic acid may be hydrophobized by pretreatment with various alkoxysilane-based silica coupling agents, alkoxysilanes that are not silica coupling agents, or a combination thereof, to make precipitated silica more hydrophobic prior to introduction into such hydrophobic compositions. rubber.

For example, and not intended to be limited, see U.S. Patent No. 5,698,619.

In one aspect, it was observed that such prehydrophobization of the precipitated silica with a combination of alkoxiorganomercaptosilane and alkylsilane (e.g. alkoxysilane), prior to their addition to the uncured rubber composition, dramatically reduced cold deformation hardness. sulfur-cured rubber composition, in a sense to reduce its storage modulus (G1) by deformations below 50 percent, compared to a rubber composition containing the functionalized elastomer where the precipitated silica is hydrophobized in situ within of the rubber composition rather than being prehydrophobized prior to addition to the rubber composition.

Accordingly, a challenge is presented to undertake an assessment of how to intensify (increase) such low cold-forming hardness property of the rubber composition containing the functionalized elastomer and the prehydrophobized silica. Several approaches to achieve this desired increase in low cold deformation hardness, without significant loss of rolling resistance predictive laboratory properties for a tire tread rubber composition, are listed '' · f. Ί 'in the following paragraphs; In some cases, separate technologies from each other can be combined to give the best iglobal approach.

A first embodiment is the inclusion of a hydrophilic precipitated silica in such a functionalized elastomer containing rubber composition to create double portions of precipitated silica in the rubber composition, i.e. a combination of prehydrophobized precipitated silica and hydrophilic precipitated silica ( precipitated silica which has not been prehydrophobized), where the functional groups on the functionalized elastomer are first reacted with the hydroxyl groups on the hydrophilic precipitated silica and thereafter allowed to react with the remaining hydroxyl groups on the said hydro precipitated silica. -phobic (hydroxyl groups remaining on the precipitated silica after it has been prehydrophobized) (in the absence of silica coupling agent added to the rubber composition). By this embodiment, it is believed that a new reinforcement mesh containing the prehydrophobized precipitated silica can be created for the functionalized elastomer containing rubber composition, particularly for the benefit of a tire tread of such rubber composition. This results from the functionalized elastomer being the only hydrophilic silica binding mechanism added, since no coupling agent is present to bind the elastomer to the silica, independent of the functional group on the elastomer. Historically, various rubber compositions and tires with their components have been proposed which contain double precipitated silica in a form of a combination of prehydrophobized precipitated silica together with precipitated silica which is hydrophobized in situ within the rubber composition. an added silica binding agent. For example, and not intended; be limiting, see U.S. Patent Nos. 4,474,908, 5,780,538, 6,127,468 and 6,573,324 and U.S. Patent Application No. 2005/0009955. However, this step-by-step interaction with the hydrophilic and hydrophobic precipitated silicas of said first embodiment is believed to be a significant departure from such past practice. A second embodiment of this assessment is the inclusion of a hydrophilic precipitated silica (precipitated silica which has not been prehydrophobized sod) and a silica coupling agent in such a functionalized elastomer containing rubber composition to create double portions of precipitated silica in the rubber composition, namely a combination of prehydrophobized precipitated silica and hydrophilic precipitated silica, where the functional groups on the functionalized elastomer are first allowed to react with the hydroxyl groups of the prehydrophobized silica and thereafter allowed to react with the groups. hydroxyl on the hydrophilic precipitated silica, where the silica coupling agent is allowed to react with the hydroxyl groups contained on both the prehydrophobized precipitated silica and the added hydrophilic precipitated silica. .

By this embodiment, it is believed that a new reinforcement mesh can be created containing the combination of pre-hydrophobized and hydrophilic precipitated silica coupled reactor silica added to the functionalized elastomer-containing rubber composition, particularly for the benefit of a tire tread of such a rubber composition j A third embodiment of this assessment is to combine the short fiber reinforcement together with the functionalized elastomers with any of the aforementioned first and second styles to promote an improvement of (a) increase in the low hardness properties of cold deformation of the rubber composition, while substantially maintaining the cured physical properties of the rubber composition, to promote improved rolling resistance (promote reduced rolling resistance) for tires when such rubber compositions are used in the following tire tread applications. Historically, short fiber reinforcement has been used in a variety of rubber compositions, including tire tread rubber compositions. However, it is believed that this proposed use of such short fibers is a significant departure from such prior use of short fibers emr in a rubber composition mixture containing functionalized elastomers combined with prehydrophobized silica. Consideration should be given to the addition of hydrophilic precipitated silica to such combined rubber compositions as described in the first embodiment of this invention. Thus, one could have a rubber composition comprised of functionalized elastomer capable of binding to a prehydrophobized silica combination (a precipitated silica having been pretreated prior to its addition to an internal rubber mixer). and hydrophilic silica (precipitated silica with pre-treatment) combined with a short fiber addition. Such short fibers may be in the form of, for example, individual fibers or cut yarns of a plurality of fibers. Such short fibers may be comprised of at least one of natural and synthetic fibers, such as, for example, at least one of nylon, aramid, polyester, rayon, cellulose and cotton.

A fourth embodiment of this invention is to add a resin formed in situ to the rubber of any of the first, second and third embodiments mentioned above, as a product of a combination of methylene donor and methylene receptor.

Historically, resin products from a methylene donor and methylene receptor, formed in situ within a rubber composition, have been proposed in a variety of rubber compositions, including rub band rubber compositions. I dages of tires. However, their inclusion in any of the first, second and third modalities mentioned above is believed to be a significant departure from such past practice. Examples of methylene donor and methylene receptor systems are discussed in U.S. Patent No. 3,517,722. They are representative of donors of • i. Methylene, for example hexamethyltothiotramine and hexamethoxymethylmelamine. They are representative of methylene receptors; for example, resorcinol, resorcinol monobenzoate, phenolic cashew oil resin, polyhydric phenoxy resin and reactive phenol / formaldehyde resin. i; . It is therefore a particular challenge to evaluate the inclusion of at least one or a combination of the following materials, as described in the different embodiments, in a rubber composition containing a functionalized diene elastomer and prehydrophobized silica to determine its impact on the low hardness of cold deformation, desirable to promote its increase, and also its elasticity property, which would be desirably maintained, ού the improved rolling resistance performance (the reduction in rolling resistance performance). ) on tires when such rubber compositions are used are tire treads, particularly. : I. *; (A) Combination of sequentially added hydrophilic and prehydrophobized precipitated silica. . (B) combination of hydrophilic precipitated and sequential prehydrophobized silica, '': (i) added together with silica coupling urant, (C) short fiber reinforcement in a distinct short fiber dispersion form with or No added hydrophilic precipitated silica and with or without added silica coupling agent, and (D) resin product of a methylene donor and methylene receptor formed in situ in the rubber composition, with or without added hydrophilic precipitated silica and with or without added silica coupling agent and with or without distinguishing short fibers. '' In the description of this invention, the term "phr" refers to refers to parts by weight for a material or ingredient per 100 parts by weight of elastomer (s). The terms "rubber" and "elastomer" may be used interchangeably unless otherwise stated. The terms "cure" and "vulcanize" "can be used by hand interchangeable unless otherwise specified. Summary and Practice of the Invention According to this invention, a rubber composition is comprised of, based on weight by weight per 100 parts by weight of rubber (phr): (A) 100 phr of at least one elastomer a diene-based composition comprising: (1) at least one functionalized diene-based elastomer, or (2) a combination of at least one functionalized diene-based elastomer and at least one non-functionalized diene-based elastomer, wherein the said combination contains more than 50 weight percent of said functionalized diene-based elastomer (s), and (B) about 30 to about 120 phr of charge. reinforcement comprised of: (1) precipitated silica, or (2) a combination of precipitated silica and rubber reinforcing carbon black containing up to about 65 phr rubber reinforcing carbon black; wherein said precipitated silica is comprised of: (a) prehydrophobized precipitated silica (hydrophobized precipitated silica prior to its addition to the rubber composition) and optionally a silica coupling agent added to said rubber composition, or; (b) a combination of prehydrophobized precipitated silica and hydrophilic precipitated silica and optionally a silica coupling agent added to said rubber composition; wherein said prehydrophobized precipitated silica is hydrophobized prior to its addition to the rubber composition by treatment with:; (i) at least one of an alkylsilane and alkoxysilane, particularly an alkoxysilane, or; (ii) a combination of at least one of an alkylsilane and alkoxysilane (particularly an alkoxysilane) together with at least one of an organoalkoxysilyl polysulfide and organomercaptoalkoxysilane, or '(iii) at least one of a polysulfide of wherein the hydrophilic precipitated silica is optionally hydrophobized in situ within the rubber composition and is hydrophobized by treatment within the rubber composition with at least one of an alkylsilane and alkoxysilane, particularly an alkoxysilane, or | ; (v) a combination of at least one of an alkylsilane and alkoxysilane (particularly an alkoxysilane) together with an alkoxysilane and at least one of an organoalkoxysilyl polysulfide, or (vi) at least one of an organoalkyl polysulfide and organomercaptoalcoxysilane, e.g. | ; ; · ’·. I ·. Wherein said additional die-based elastomer is comprised of at least one isoprene and 1,3-butadiene polymer and styrene and at least one isoprene and 1,3-butadiene copolymers; and ; wherein said functionalized elastomer is comprised of at least one of functionalized cis 1,4-polyisoprene elastomer: (functionalized IR), functionalized cis 1,4-polybutadiene elastomer (functionalized BR), functionalized butylene / butadiene (SBR functionalized), functionalized isoprene / butadiene copolymer elastomer (functionalized IBR) and functionalized styrene / isoprene / butadiene (functionalized SIBR) and elastomers prepared in organic solvent solution coupled with at least one deisoprene and 1,3-butadiene and styrene, with at least one of isoprene and 1,3-butadiene, wherein the functional groups of said elastomers are reactive with the precipitated silica hydroxyl groups.

In one embodiment, said rubber composition further contains at least one additive comprised of at least one of: (A) short fiber reinforcement, and (B) methylene donor and methylene receptor resin product.

Representative examples of said non-functionalized diene-based elastomers are, for example, and not intended to be limiting, cis 1,4-polyisoprene (particularly natural and synthetic rubber), 1,4-polybutadiene (particularly cis 1,4-polybutadiene) and '(A) the amine functional group reactive with hydroxyl groups on said precipitated silica, or (B) the siloxy functional group, including the end chain siloxy groups reactive with hydroxyl groups on said precipitated silica, or (C) a combination of reactive amine and siloxy functional groups with said hydroxyl groups on said precipitated silica, or: (D) a combination of thiol and siloxy reactive functional groups with the groups hydroxyl on said precipitated silica, or (E) a combination of reactive imine and siloxy functional groups with hydroxyl groups on said precipitated silica, or; (F) hydroxyl functional groups reactive with said precipitated silica, or (G) epoxy groups reactive with hydroxyl groups on said precipitated silica, or; (H) carboxyl groups reactive with hydroxyl groups on said precipitated silica. ;

In one embodiment, said functionalized elastomer contains functional group (s) comprised of: "For functionalized elastomers, they are representative of functionalized SBR elastomers, for example, functional chain SBR elastomers mentioned in US Patent No. 6,936,669. It is representative of a combination of amino-siloxy functionalized SBR elastomers with one or more elastomer-linked amino siloxy groups, for example, the R $ HPR355® and the functionalized SBR elastomers. with amino siloxy mentioned in US Patent Application Publication No. 2007/0185267.

Representative end-functional styrene / titanium elastomers with a silane sulfide group are; for example mentioned in patent publication WO 2007/047943. It is representative of hydroxy functionalized SBR elastomers, for example Asahi's Tufdene 3330®. 'J. ·. It is representative of epoxy functionalized SBR elastomers, for example Asahi's Tufdene E50®. j *; . For example, there is provided a method of preparing a composition of: 1: ''}. precipitated silica-reinforced rubber for a tire tread, which is comprised of at least two steps of; non-productive preparatory mixes, then Ϊ ·. . . ') l [. by a productive mixing step comprising, based on parts by weight per 100 parts by weight of rubber (phr): (A) Combining a pre-hydrophobized pre-precipitated silica with a composition of. t; [rubber containing at least one conjugated diene-based elastomer including said functionalized elastomer in at least one preparative non-productive mixing step in an internal rubber mixer (at a temperature of for example in a range from about 135 ° C to about 175 ° C); (B) removing said prehydrophobized precipitated silica-containing rubber composition from its internal rubber mixer (and allowing said rubber composition thereafter to cool to a temperature below about 40 ° C); (C) Combining a hydrophilic precipitated silica with said rubber composition containing prehydrophobized precipitated silica in the same mixing step or at least ·. . . t. '. V is a step of (subsequent and different preparative non-productive mixing) (subsequent to said non-productive preparatory mixing step; in which the prehydrophobized precipitated silica diite is added) in an internal rubber mixer (in the absence of addition,! A silane-containing hydrophobising agent for said hydrophilic precipitated silica to form a rubber composition which contains double silica moieties in a form of a combination of said prehydrophobized precipitated silica and said silica. A hydrophilic precipitate, wherein the prehydrophobized silica is hydrophobized prior to its addition to said rubber composition with at least one hydrophobizing agent comprised of a hydrophobic agent. alkoxysilane, organosilbxysilyl polysulfide and organomercaptoalcoxysilane.

For example, a preparation method is provided. of a precipitated silica-reinforced rubber composition for a tire wheel tread comprising at least one preparative non-productive mixing step followed by a productive mixing step comprising, based on parts by weight per 100 parts by weight of rubber (phr): (A) combining a prehydrophobized precipitated silica with a rubber composition containing at least one conjugated diene-based elastomer including said furcationized elastomer in at least one preparative non-productive mixing step in an internal rubber mixer (in a temperature of, for example, in a range from about 135 ° C to about 175 ° C); ; (B) Combining a hydrophilic precipitated silica with said 1'J rubber composition containing prehydrophobized precipitated silica in an equal or different non-productive mixing step (ahtes or after the addition of said prehydrophobized precipitated silica) in a mixer. internal rubber (in the absence of the addition of a silane-containing hydrophobizing agent to said precipitated silica to add hydrophilic), to form a rubber composition containing double silica moieties in a form of a combination of said prehydrophobized precipitated silica and said hydrophilic precipitated silica, wherein said prehydrophobized silica is hydrophobized prior to its addition to said rubber composition with at least one hydrophobization agent comprised of an alkoxysilane, alkoxysilane, organosiloxysilyl polysulfide and organomercaptoalkoxysilon. ; ;

In practice, the mixture of hydrophilic precipitated silica with at least one diene-based elastomer including said functionalized elastomer may be administered, for example: ; ! i 'i ·. (A) in the same non-productive mixing step, before or after the addition of the prehydrophobized precipitated silica, or (B) in a separate non-productive mixing step, after the addition of the prehydrophobized precipitated silica, or! (C) in a separate non-productive mixing step, after addition of the prehydrophobized precipitated silica, with a further separate non-productive mixing step between them, or! í. ·. i. . (D) is a separate subsequent productive mixing step in which sulfur and sulfur curing agents are added to the rubber composition.

In practice, as indicated above, said hydrophobizing agent for hydrophobizing said hydrophilic precipitated silica, for the purposes of this invention, is at least one of alkylsilane, alkoxysilane, organosiloxysilyl polysulfide, alternatively with a combination of alkoxysilane and at least one. of said polysulfide: from organosiloxysilyl or organomercaptoalkoxysilane.

In practice, it is representative of said organoalkoxysilyl polysulfides, for example, a bis (3-trialkoxysilylpropyl) polysulfide having an average of about 2 to about 4, optionally an average in a range of about 2 to about 2, 6, or in a range of from about 3.2 to about 3.8, sulfur atoms on their polysulfide bridge. Illustrative of said bis (3-trialkoxysilylalkyl) polysulfide is comprised of a bis (3-triethoxysilylpropyl) polysulfide.

In practice, it is representative of said alkoxysilane, for example, an alkoxysilane of the general formula (I): (I) Zn Si R 4 -N where R is a saturated alkyl radical having from one to 18, preferably from one to 8, atoms. carbon, such as, for example, methyl, ethyl, isopropyl, n-butyl and octadecyl radicals, n is a value from 1 to 3 and Z is an alkoxy radical represented as (R 10) -, where R 1 is a saturated alkyl radical having from one to 3 carbon atoms, such as, for example, methyl, ethyl and isopropyl radicals, preferably at least one of methyl and ethyl radicals. ;

Representative examples of alkoxysilanes of Formula (I) are, for example, trimethoxy methyl silane, dimethoxy dimethyl silane; methoxy trimethyl silane, trimethoxy propyl silane, trimethoxy octyl silane, trimethoxy hexadecyl silane, dimethoxy dipropyl silane, triethoxy methyl silane, triethoxy propyl silane, triethoxy octyl silane, and diethoxy dimethyl silane.

Accordingly, said alkoxysilanes have an alkoxy group being reactive with hydroxyl groups (e.g. silane groups) contained on the surface of the precipitated silica aggregates.

In the practice of this invention, the rubber composition may be comprised of various conjugated diene-based elastomers in addition to said functionalized elastomer. Such additional diene-based elastomers may be, for example, at least one of the polymers comprised of at least one of isoprene and 1,3-butadiene, and styrene copolymers and at least one isoprene and 1,3-conjugated diene conjugated diene hydrocarbon. butadiene as well as elastomers prepared by polymerization in organic solution coupled with tin. For example, representative of such additional elastomers are natural cis 1,4-polyisoprene rubber, cis-rubber. Synthetic 1,4-polyisoprene, cis-1,4-polybutadiene rubber, high-vinyl polybutadiene rubber having a 1.2-vinyl content in a range of from about 10 percent to about 90 percent , styrene / butadiene copolymer rubber (SBR) (copolymers prepared by polymerization in aqueous emulsion or organic solution) and including SBR prepared by organic solvent polymerization having a 1.2 vinyl content in a range of about 10 to about 90 percent, based on its polybutadiene-derived part, and a polystyrene content in a range of about 10 to about 60 percent, based on the copolymer, the styrene / high-content copolymer rubber trans 1,4-butadiene having a trans-1,4 content in the range of about 40 to about 80 percent, based on its polybutadiene-derived part, bor- '; ' · 1 . styrene / isoprene / butgdiene terpolymer crack, butadiene / acrylonitrile rubber, styrene / ispprene and deisoprene / butadiene copolymer rubber, 3,4-polyisoprene rubber and trans rubber 1.4 -polibutadiene !. Additional representative examples of such additional elastomers are, for example, tin or silicon-coupled elastomers prepared by polymerization in orphanous solution, such as, for example, tin-coupled styrene / butadiene copolymers. Silicon can also be used. !

Styrene / butadiene-tin-coupled copolymers can be prepared, for example, by introducing a tin-coupling agent during the styrene / 1,3-butajtiene monomer copolymerization reaction in an organic solvent solution, usually in the or near the end of the polymerization reaction. Such coupling of styrene / butadiene copolymers is well known to those. 1 ; Having skill in such a technique. ι I '} ·. ·. For such coupled elastomers, it is normally desired that at least 50 per cent and more generally within a range of about 60 to about 85 per cent of the bonds. '| Sn (tin) in the tin-coupled elastomers are attached to the i units; ·. {j-. butadiene of the styrene / butadiene tablet polymer to create Sn-dienyl bonds, such as butadienyl bonds. ; ; í. The creation of tin-dieriyl bonds can be carried out in a variety of ways, such as, for example, sequential addition of butadiene to the copolymerization system or the use of modifiers to alter the reactivity ratios of styrene and / or butadiene for copolymerization. Such practices, whether employed with a batch copolymerization system or with a continuum, are believed to be well known to those having skill in such a technique. Several tin compounds, particularly the organo tin compounds, may be used for coupling the elastomer. Representative of such compounds are, for example, alkyl tin trichloride, dialkyl tin dichloride, which produce variants of a tin-coupled styrene / butadienyl copolymer elastomer, although a trialkyl tin monochloride may be used which it would simply produce a tin-terminated copolymer. ; !

Examples of tin modified or coupled elastomers are, for example, the styrene / butadiene copolymer elastomers exemplified, for example, in U.S. Patent No. 5,064,901. r. Several commercially available amorphous synthetic precipitated silicas (precipitated silicas) may be used for the precipitated silicas for this invention. Such silicas may be characterized, for example, by their BET and CTAB surface areas. They are representative! of such silicas, for example, only and without limitation, PPG L · 't' - · '· Industries silicas under the trademark Hi-Sil, under the names 210, 243, etc .; Rhodia silicas, under the names Zeosil 1165MP and Zeosil 165GR, Evonic silicas under the names VN2 and VN3, and Huber silicas, such as Zeopol 8745 and Zeopol 8715.

It is readily appreciated by those having skill in the art that the rubber composition would be combined by the methods generally known in the rubble combining technique, such as mixing the various sulfur vulcanizable constituent rubbers with the various commonly used additive materials such as for example curing aids such as sulfur, activators, retarders and accelerators, processing additives such as oils, resins including sticking resins and plasticizers, fillers, pigments, fatty acid, zinc oxide, waxes, antioxidants and anti-zonizers, peptizing agents and reinforcing materials. The presence and relative amounts of the above additives are not considered to be an aspect of the present invention unless otherwise indicated which is more directed to a tire having: a tread including the tread running surface of a rubber composition containing double portions of silica in the form of a prehydrophobized precipitated silica and a hydrophilic precipitated silica in combination with a functionalized elastomer containing hydroxyl group reactive functionalities (e.g. silanol groups) on the precipitated silica.

Tires can be produced, shaped, molded and cured by a variety of methods, which will be readily apparent to those having skill in such a technique. ; ; The following Example is provided to further understand the invention. Parts and percentages are by weight unless otherwise indicated. EXAMPLE I (Control and Comparative Rubber Sample) Experiments were conducted to evaluate the effect of using a combination of hydrophilized hydrophobic precipitated silica in situ on an internal rubber mixer (e.g., Banbury mixer) using a added silica coupling agent as compared to a prehydrophobized precipitated silica without added hydrophilic silica or addition of a silica coupling agent within a rubber composition rubber containing a functionalized elastomer. This example will address the issues of this approach as to obtaining a rubber composition for tread component applications in a tire, where dramatic improvement (reduction) in rolling resistance can be obtained, with a corresponding reduction in low hardness property. of cold deformation, which could negatively impact the wet and dry handling performance of the tire.

The functional groups of the functionalized elastomer are understood to be reactive with the available hydroxyl groups on the precipitated silicas. Rubber composition A (control rubber sample) represents the addition of hydrophilic precipitated silica in the presence of silica coupling agent to a rubber composition containing a functionalized SBR polymer (stretch rubber / butadiene rubber) and a non-functionalized PBD polymer (cis 1,4-polybutadiene rubber). Sample B (comparative rubber sample) represents the use of a prehydrophobized precipitated silica added to the same polymer combination in the absence of any added silica coupling agent. The Rubber Sample A and Rubber Sample B compositions were prepared by mixing the elastomers with the precipitated silica fillers and silica coupling agent, when added; in at least one initial non-productive mixing step followed by a sequential non-productive (NP) mixing stage in an internal rubber mixer (Banbury rubber mixer) for about 4 minutes to a temperature of about 160 ° C. ° C. The rubber compositions were subsequently mixed in a productive mixing stage (P) in an internal rubber mixer (Banbury mixer), with a sulfur curing package, namely sulfur curing and accelerators), by fencing. 2 minutes to a drop temperature of, for example, about 115 ° C. The rubber compositions were removed from the internal mixer after each mixing step and cooled to below 40 ° C between each individual non-productive mixing stage and prior to the final productive mixing stage. The basic formulation for the Sample! Control Rubber A and Comparative Rubber Sample B are shown in Table 1 below, expressed in parts by weight per 100 parts of rubber (phr), unless otherwise indicated. .

Table 1 First Non-Productive Mixing Stage (NP1) Parts by weight (phr) Functionalized SBR Elastomer1! 60 Natural cis 1,4-polyisoprene rubber2 40 Hydrophobized precipitated silica (pre-treated) 30 and 84 Hydrophilic precipitated silica (untreated) 4 80 and 0 Process oil, auxiliaries and wax 22 Coupling agent5; 6.4 and 0 Anti-degradation (s) 6: 2 Carbon black, added, rubber reinforced7 3 Fatty acid8 2 Zinc oxide! 3 and 0.5 (for Rubber Sample B) Productive Mixing Stage (P);

Sulfur i 1.5 Accelerator (s) 9 2.9 and 4.2 (for Rubber Sample B) 1A styrene / butadiene elastomer prepared by polymerization in a tin-coupled solution containing a siloxyl (siloxy) functional group in the chain terminal, rea- '' t-. . . hydroxyl groups of a precipitated silica; t'· 2Natjjral cis-1,4-isoprene cis-rubber (TRS20) 3Prehydrophobized (pretreated) precipitated silica with a combination of mercaptoalcoxysilane and alkylsilane (eg alkoxysilane) as PPG Agilon 400® Industries 4 Hydrophilic precipitated silica (not prehydrophobized) as Rhodia's Zeosil 1165MP® 5 Coupling agent as a bis (3-triethoxysilylpropyl) polysulphide having an average of about 2 to about 2.6 sulfur linkers on its bridge polysulphidic such as Si-266® from Evonic} 6Amine based graders i 7Rubber reinforcing smoke N299, a designation of ASTM 8Mainly comprised of stearic, palmitic and oleic acids 9Slflfamide and guanidine sulfur cure accelerators The following Table 2 illustrates the curing behavior and the various physical properties of rubber compositions based on the basic formula of Table 1 and described herein as a Sample Rubber Control A and Comparative Rubber Sample B: Where cured rubber samples are examined, such as stress-strain, hot elasticity and hardness, the rubber samples were cured for about 12 minutes at a temperature about 170 ° C.

Table 2 ; i: J samples; * Comparative Control Materials (phrV i A B

Functionalized SBR elastomer 60 60 Hydrophilic silica (not prehydrophobized) 80 0 Prehydrophobized silica 0 84 Silica Coupling Agent | 6.4. 'i. · Properties I

Predictive Handling Properties One-way Tire Tread, Cured Storage Module (G1) 1 to 100 ° C, 11 Hertz (RPA) 1 \ ... "1 percent deformation (MPa) j 5116 1300 10 percent (MPa) '2145 1070 Predictive Tire Tread Rolling Resistance Properties * (The highest values for elasticity and the lowest values for Tan Delta are: I predict the beneficial reduction in tire rolling resistance ). „Elasticity (100 ° C) *. · 58.64 - Tan delta, (100 ° C, 10% deformation, 11 Hertz) 0.17 0.12 Tire Tread Predictive Wet Performance Properties Elasticity, 0Â ° C, 7.9.3, Predictive Property of Tire Tread Wear, Abrasion Resistance, i J,: i (Abrasion Rate, Smaller is Better) í Grosch2 Abrasion, Medium , mg / km j 126, 85-Tear Resistance3, · (foot adhesion) N · '. · .A 95 ° G for the test · ·,; 82 56 *' í 1 Ac data according to the Rubber Process Analyzer (RPA) · * s2 Grosch abrasion rate scraper LAT-100, measured in terms of mg / km of fractionated rubber. The test rubber sample is placed at a slope angle under constant load (Newtons); as it travels a certain distance over a rotating abrasive disk (eg disk from.HB Schleifmittel GmbH). In practice, a Lower Abram gravity test could be run, for example, on a 20 Newton load, 2 ° tilt angle, ile disc speed 40 km / h for a distance of 7,500 meters; a medium abrasion gravity test can be run, for example, on a 40 Newton 'load, 6 ° tilt angle, 20 km / h disc speed and 1,000 meter distance; A high abrasion severity test can be run, for example, on a 70 Newton load, 12 ° tilt angle, 20 km / h disc speed and 250 meter distance; and an Ultra-high abrasion gravity test can be run, for example, on a 70: Newtons load, 16 ° tilt angle, 20 km / h disc speed and 500 meter distance. ; . 3D data obtained from agreement with a tear resistance test (peal adhesion) to determine interfacial adhesion between two samples of a rubber composition. In particular, such interfacial adhesion is determined by removing one rubber composition from the other at a right angle to the untested test sample with the two ends of the rubber compositions being separated at an angle of 180 ° to each other. using an Instron instrument at 95 ° C and described as force in Newtons.

It can be seen from Table 2 that comparative Arrtostra B, which contains the prehydrophobized silica in the presence of a functionalized SBR elastomer, provides a dramatic improvement in elasticity and delta that would predict a significant improvement in resistance to tire rolling.when such compound is used in a tire tread component. -; . '· ·' Í. In contrast, the same Comparative Sample B, which contains the pre- silica. \ | · T · ': hydrophobized and the functionalized SBR shows a dramatic reduction in the low hardness properties of cold strain at 1 and 10 percent strain, which would predict one. j. significant loss of wet and dry handling performance. The challenge, therefore, is to maintain predictive improvement in rolling resistance at the same time! can improve compound performance, predictive of good wet and dry handling. The following examples will show the approaches to materials that have been attempted to achieve this goal. EXAMPLE II Experiments were conducted to evaluate the effect of adding untreated hydrophobic precipitated silica to the hydrophobized (pretreated) precipitated silica in the internal rubber mixer (Banbury mixer) without the addition of silica coupling agent to the compounds (Rubber Composition Samples). Control Rubber Sample C contained 84 phr of pre-treated silica, while Rubber Samples D, E and F contained, in addition to 84 phr of pre-treated silica, respectively 5, 10 and 15 phr of precipitated silica not pretreated, therefore hydrophilic. This example represents an attempt to increase the low cold deformation hardness of the compound containing the pre-treated (pre-hydrophobized) precipitated silica by the addition of several levels of untreated (therefore hydrophilic) precipitated silica without the addition of agent. coupling silica. The success of this approach and others listed in the following examples demonstrates an ability to increase the low hardness of cold forming without significant penalty for hysteresis for the rubber composition for which it is desired. a minor hysteresis of the rubber composition to promote an improvement in (lower) tire rolling resistance for the tire with a tread of such rubber composition. The basis of the rubber composition (rubber compound) is illustrated in Table 3 below, where parts and percentages are described in terms of parts by weight unless otherwise indicated. Table 3 First Non-Productive Mixing Stage (NP1) Parts by weight (phr).

Functionalized SBR rubber1 60 Natural rubber2 40 Hydrophilic precipitated silica (untreated) 3 0, 5, 10, 15 Prehydrophobized precipitated silica4 84, 84, 84, 84 The ingredients used are as identified in Table 1 of Example 1, except for quantities and unless otherwise stated. | Table 4 below illustrates the healing behavior and the various physical properties. Rubber compositions based on the compounds of [Table 3. Where cured rubber samples are examined, such as stress-strain, hot elasticity and hardness values, the rubber samples they were cured for about 12 minutes at a temperature of about 170 ° C.

Table 4 j '' '·' í. . ·· 1 ; ; Samples (phr) Materials (phr) i Ç D E F

Functionalized SBR elastomer I 60 60 60 60 60 Hydrophilic precipitated silica (not pretreated) 0 5 10 15 Prehydrophobized precipitated silica} 84 84 84: 84 Silica coupling agent; 0 0 0 0 Properties; I 'I. i. ; ] Predictive Handling Properties Tire Tread Cured Storage Module (G1) 1 to 100 ° C, 11 Hertz (RPA) 1 1 percent deformation (MPa) J 1220 1367 1599 2338 10 percent deformation (MPa) í 1000 1076 1183 1489 Predictive Properties of Tire Tread Rolling Resistance j '; . : j '"|' (Higher values for elasticity and lower values for Tan Delta are -. · i ·. predictive of beneficial reduction in tire rolling resistance) Elasticity (100 ° C) I 63 60 59 59 Tan delta (100 ° C, 10% yield1 j 11 Hertz) 0.121 0.118 0.114 0.091 Predictive Wet Traction Property of Tire Tread Elasticity, 0 ° C; j 7.3 7.6 7.6 7.7 7 .8 Wear Predictive Property gives Tire Tread Abrasion Resistance; · '·' (Abrasion Rate) (Lower is better) j Grosch Abrasion2, Average, mg / km; 53 59 65 74 Tear Resistance3, ( peal resistance) at 95 ° C for the test 61 72 55 64 t.'1 · 2,3Test procedures as in Example I

It can be seen from Table 4 that the low cold deformation hardness of Rubber Sample (Compound) C, the control, can be significantly increased with only a modest full hysteresis, as indicated by elasticity and as indicated by the physical properties of tan delta by the addition of low levels of untreated precipitated silica (hence hydrophilic precipitated silica) in Compounds (Rubber Samples) D, EeF. This is considered to be significant in a sense that is seen to be profitable, therefore! the low hysteresis properties of rubber promoted by pre-treated precipitated silica (precipitated silica; prehydrophobized) through; of small additions of hydrophilic precipitated silica, with an Improvement resulting from the low hardness properties of cold deformation, which is significant to promote handling performance. wet and tire section to a tire tread. EXAMPLE III jj Experiments were conducted to evaluate the effect of adding untreated precipitated silica to hydrophobized pre-treated precipitated silica in the internal rubber mixer (Bapbury mixer) combined with the addition of coupling agent to the compounds. (Rubber samples)., The compound (Rubber sample) G, o; control contained 84 phr of pre-treated precipitated silica (pre-hydrophobized precipitated silica), while compound (B-sample) H contained 63 phr of precipitated, pre-treated hydrophobized silica and 20 phr of precipitated silica untreated (therefore hydrophilic precipitated silica) and 1.6 phr of coupling agent. Compound (Rubber Sample) l1 contained 42 phr of silica. | precipitated, pretreated, prehydrophobized, and 40 phr of untreated precipitated silica; . (i.e., added hydrophilic precipitated silica) and 3.2 phr of acetylating agent. plantation. All compounds (rubber AmoStras) contained a total of 80 phr of silica. i | i j;

This example represents one; attempting to increase the low hardness of cold deformation of the compound (rubber composition) containing pre-treated precipitated silica (prehydrophobized precipitated silica) by the addition of two levels of untreated precipitated silica (hydrophilic precipitated silica), and by the addition of coupling agent. The success of this approach illustrates an ability to; Increase the low hardness of cold deformation without! . ,. 1 '1 a feather means paper hysteresis; which is desired to be low to promote improvement, i. '! ; improvement in rolling resistance of the tire. ! Table 5 below illustrates a base formulation for the First Stage of Mystery. · F. Non-Productive Rubber Sample Size, parts shown by weight.

Table 5 ''! ; I t '' í:. ·;

First Non-Productive Mixing Stage (NP1) Parts by weight (phr) »· '' 1 '' 'I' Functionalized SBR rubber 60 * í '' '· ·.

Natural rubber2 j i 40 '• f - j' ·; Hydrophilic precipitated silica (not pretreated) 30, 20, 40 Hydrophilic precipitated silica4: 84, 63, 42 l '‘ί ς' '! Silica Coupling Agent 0,1,6,3,2 The ingredients used are as identified in Table 1 of Example 1, except for the amounts and unless otherwise indicated. Table 6 below illustrates the healing behavior and the various physical properties. í. i. rubber compositions based on the basic formula of Table 5. Where cured rubber samples are examined, such as stress-strain, hot elasticity and hardness values, the rubber samples were cured for about 12 minutes at a temperature of about 170 ° C.

Table 6: Materikis samples (phr); , G Η I

Functionalized SBR elastomer 60 60 60 Hydrophilic precipitated silica (not pretreated) 0: 20 40 Prehydrophobized precipitated silica 84 63 42 Silica coupling agent; 01.6 3.2.

Properties ; 'Predictive Handling Properties of Tire Tread Cured Storage Module (G') 1 at 100 ° C, 11 Hertz (RPA) 1 1 percent strain (MPa) 1399 1803 2585 10 percent strain (MPa) 1112 1341 1713 Predictive Properties of Tire Tread Rolling Resistance; ; (Higher values for elasticity and lower values for Tan Delta are predictive of beneficial reduction in tire rolling resistance.) Elasticity (100 ° C) I 64 66 65 Tan Delta (100 ° C, 10% deformation, 11 Hertz) o; 117 0.104 0.112 Tire Tread Predictive Wet Traction Property Elasticity, 0 ° C 8.8 8.8 9 Abrasion Resistance (Abrasion Rate) (Lower is better) Grosch Abrasion2, Average, mg / km 99 107 117 Tear Strength3, (peal resistance) NA 95 ° G for test 1 57 66 59 1'2,3Test procedures as in Example I

It can be seen from Table 6 that the low cold strain hardness of Compound (Rubber Sample) G, the control, can be significantly increased without any penalty for hysteresis as measured by elasticity and tan delta by the addition of precipitated silica. Untreated (hydrophilic precipitated silica) and coupling agent for Experimental Compounds (Rubber Samples) Hei. ;

This is considered to be significant in a sense that one can take advantage of the low hysteresis properties promoted by the pretreated precipitated silica (pre-hydrophobized precipitated silica) while improving the properties of low deformation hardness. the cold composition of the rubber, which are important for pro- · Move the wet and dry handling performance of the tire to a tire tread. ! . EXAMPLE IV; Experiments were conducted to evaluate the effect of adding a methylene receptor and methylene donor formed in situ (rubber formed) resin product to the rubber composition containing the functionalized elastomer and: (A) Combined precipitated silica pre-treated, (prehydrophobized), or (B) Combination of pre-treated precipitated silica, (prehydrophobized) silica coupling agent and untreated precipitated silica (hydrophilic precipitated silica). Rubber Corp. (Rubber Sample) J, the control, contained 84 phr of pre-treated (hydrophobized) precipitated silica, while Compound (Rubber Sample) K contained 84 phj- of pre-treated (hydrophobized) precipitated silica and 1.75 phr of a resin product formed; methylene receptor and methylene donor in situ, and the compound (Rubber Sample) contained 84 phr of the pretreated (hydrophobized) precipitated silica combined with 3.5 phr of the. resin product. Compound (Rubber Sample) M contained 63 phr of untreated precipitated silica (hydrophobic) and 20 phr of untreated precipitated silica (hydrophilic) and 1.6 µg of coupling agent. Compound (Rubber Sample) N was similar to Compound (Rubber Sample) M (except that it also contained 3.5 phr of resin product. All compounds (Rubber Sample) contained a total of 80 phr of precipitated silica The following Table 7 illustrates a base formulation for the First Non-Productive Mixing Stage for Rubber Samples, parts by weight.

I have tabulated 7.

First Stage Non-Productive Mixing (NP11 Parts by weight (phr) Functionalized SBR rubber1 j 60. I,. · "Ϊ,! ·.

Natural rubber> 40 Hydrophilic precipitated silica (not pretreated) 3 - 0: 0, 0, 20, 20 Prehydrophobized precipitated silica4.14.84, 84, 84, 63, 63! ..: ς; {.

Silica coupling agent; 0, 0.0 1,6,1,6 Resin product ([methylene donor / recipient) 10 0/0, 1 / 0.75, 2 / 1.5, 0/0, 2 / 1.5 Os Ingredients used are as identified in Table 1 of Example 1 except for the amounts and unless otherwise indicated. Methylene receptor as a reactive phenol / formaldehyde resin as HRJ-1587® from SI Group, and methylene donor as hexamethoxymethylmelamine resin as Cyrez CRA1004 from Cyrez. > Table 8 below illustrates healing behavior and the various physical properties! . i. . Where the cured rubber samples are examined, such as stress-strain, hot elasticity and hardness, the rubber samples were cured for about 12 months. minutes at a temperature of about 170 ° C.

Table 8: Material Samples (phr); J K L M N

Functionalized SBR elastomer! 60 60 60 60 60 Hydrophilic precipitated silica (not pretreated) 0 0 20 20 Prehydrophobized precipitated silica; 84 84 84 63 63 Silica Coupling Agent: 0 0 0 1.6 1.6 Resin (methylene donor / recipient); 0/0 1 / 0.75 2 / 1.5 0/0 2 / 1.5 Predictive Handling Properties of Tire Tread Cured Storage Module (G1) 1 at 100 ° C. 11 Hertz (RPA) 1 1 percent strain (MPa); 1262 1422 1470 1613 2054 10 percent deformation (MPa): 1066 1141 1159 1277 1423 Predictive Properties of Tire Tread Rolling Resistance. ; (Higher values for elasticity and lower values for Tan Delta predict the beneficial reduction in tire rolling resistance.) Elasticity (100 ° C). 63 64 63 62 61 Tan delta (100 ° C, 10% deformation, 11 Hertz) 0.124 0.115 0.111 0.109 0.130 Predictive Wet Traction Property of the Tire Tread Elasticity, 0 ° C; 9.1 9.3 9.3 8.6 9.5 Abrasion Resistance (Abrasion Rate) (Lower is better) Grosch Abrasion2, Average, mg / km: 92 100 107 93 118 Tear Resistance3, (deoeali resistance) N 1 at 95 ° C for the test ': 55 60 57 67 63 1,2,3Testing procedures as in Example I

It can be seen from Table 8 that the low cold deformation hardness of Compound (Rubber Sample) J, the control, can be significantly increased without any penalty for hysteresis as indicated by the elastic and tan delta properties by the addition of in situ resin product of methylene receptor and methylene donor as illustrated by Compounds (Rubber Samples) K and L or by use of a combination of untreated precipitated silica (hydrophilic) and silane coupling agent together with the resin product formed in situ as illustrated by Compound (Rubber Sample) No.

This is considered to be significant in a sense as it is possible to take advantage of the low hysteresis properties promoted by the pretreated (hydrophobic) precipitated silica, while enhancing the low hardness cold deformation properties which are important for promote wet and dry tire handling performance for a tire tread. . EXAMPLE V;

Experiments were conducted to evaluate the effect of adding short fibers to the pretreated (prehydrophobized) precipitated silica in the internal rubber mixer (Banbury mixer). The compound (Rubber Sample) O, the control, contained 84 phr of the pretreated (hydrophobized) precipitated silica, while the P (Q) Rubber Samples contained 2 and 4 phr, respectively, of distinct short fibers. All compounds (Rubber Samples) contained a total of 80 phr of precipitated silica. The basic formulation for Rubber Samples O, PeQ is given in Table 9 below, expressed in parts by weight per 100 parts of rubber (phr), unless otherwise indicated. ;

Table 9: First Stage Non-Productive Mixing (NP1) Parts by weight (phr) Functionalized SBR Rubber1 60) 1 'Natural Rubber2 40 - Prehydrophobized Precipitated Silica4 84, 84, 84 Kevlár® Aramid Short Fiber 0, 2, 4 Ingredients used as identified in Table 1 of Example I, except that they may be otherwise identified and an inclusion of 2 and 4 phr short fiber in the compounds (Rubber Samples) P is Q. Table 10 below illustrates the ! curing behavior and the various physical properties of rubber assemblies based on the basic formula of Table 7. Where cured rubber samples are 'examined, such as stress-strain, t'; . At the hot elasticity and hardness values, the rubber samples were cured for about 12 miriutos at a temperature of about 170 ° C.

Table 10 Samples (phr) Materials (phr) j O P Q

Functionalized SBR elastomer 60 60 60 Hydrophilic precipitated silica (untreated) 0 5 10 Prehydrophobized precipitated silica 84 84 84 Cut fiber? 0 2 4 Properties? 'i! ;

Predictive Handling Properties of Tire Tread Cured Storage Module (G ') 1, at 30 ° G, 10 Hertz (ARES); 'i? 1 percent creep (MPa) 2263 2629 3022 10 percent creep (| / IPa) ‘1725 1985 2232 Predictive Properties of Tread Rolling Resistance I. · i 1 · Tire I; : (The highest values for Elasticity and the lowest values for Tan Delta are | | (. -Predictive of beneficial reduction in tire rolling resistance) Elasticity (100 ° C) '69 58 54 Tan delta (100 ° C , 10% deformation ;, 11 Hertz) 0.097 0J114 0.109 Predictive Tire Traction Property of Tire Tread.

Elasticity, 0 ° C; 9.6 9.8 11.2 '. | Abrasion Resistance (Abrasion Rate) (Lower is better) - Grosch2 Abrasion, Average, rrjig / km. 98 90 106 '!, I. " Tear Strength, (peal resistance) N t '1 At 95 ° G for test 54 49 28 1; 2' 3Prj) Test procedures as in Example I, except the ARES test for deformity hardness at cold ;. : It can be seen from Table 10 that the low cold deformation hardness (modulus G 'at 1 percent deformation) of the Composite (Rubber Sample) O, the control, can be significantly increased with some feather for hysteresis. as indicated by the elastic properties and tan delta, by the addition of short fibers (Kevlar fibers) to the compound (Rubber Sample) containing the pretreated (thereby pre-hydrophobized) precipitated silica. ! ; This is considered to be significant in a sense that it is seen that one can take advantage of some of the low hysteresis properties (evidenced by the elastic and tan delta properties) of the rubber composition; promoted by pretreated precipitated silica (hydrophobic), while improving the low hardness of cold deformation properties (modulus G '), which are important for promoting wet and dry tire handling performance for a Tire tread.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that it is apparent from the art. Various changes and modifications can be made in it without leaving the spirit or the. . Scope of the invention. ; i - '' 1 'i:. ·}:. 'i': ’j. . ; - 'f; ':. . . '. j: '. {. k '. . , THE '

Claims (10)

Ϊ1. Rubber body, characterized in that it is comprised of, with ba. ! 'í ·. . parts by weight per 100 parts by weight of rubber (phr): (A) 1Ό0 phr of at least one diene-based elastomer comprised of: (1) at least one functionalized diene-based elastomer, or (2) ) A combination of at least one functionalized diene-based elastomer and at least one non-functionalized diene-based elastomer, wherein said combination contains more than 50 percent (by weight) of said (s). elastomer (s) based on t. · I. functionalized diene (s), and! (B) 30 to 120 phr reinforcement load comprised of: (1) precipitated silica; or (2) a combination of precipitated silica and rubber reinforcing carbon black containing up to 65 phr of reinforcing carbon black. rubber; wherein said precipitated silica is comprised of: (a) prehydrophobized precipitated silica and optionally a silica coupling agent added to said rubber composition, or (b) a combination of prehydrophobized precipitated silica and hydrophilic precipitated silica and optionally a silica coupling agent added to said rubber composition: wherein said prehydrophobized precipitated silica is hydrophobicized prior to its addition to the rubber composition by treatment with:; . (i) at least one of alkylsilane and alkoxysilane, or (ii) a combination of at least one of alkylsilane and alkoxysilane together with at least one of an organoalkoxysilyl polysulphide and at least one of organomercaptoalkoxysilane; an organoalkoxysilyl and organomercaptoalcoxysilane pisulfide, e.g. ! wherein said in situ hydrophobic precipitated silica within the rubber composition is hydrophobic by treatment within the rubber composition with: (iv) at least one of alkylsilane and alkoxysilane, or (v) a combination of alkylsilane and alkoxysilane pellum. together with at least one of an organoalkoxysilyl polysulfide and organomercaptoalkoxysilene, or i; ; (vi) at least one of an organoalkoxysilyl and organornercaptoalcoxysilane polysulfide is; ; wherein said additional diene-based elastomer is comprised of at least one isoprene polymer of at least 1,3-butadiene and styrene copolymers and at least one isoprene and 1,3-butadiene copolymers; and wherein said functionalized elastomer is comprised of at least one of functionalized cis-1,4,4-polyisoprene (functionalized IR) elastomer, functionalized cis 1,4-polybutadiene elastomer (functionalized BR), stretch copolymer elastomer -no / functionalized butadiene (functionalized SBR), functionalized isoprene / butadiene copolymer elastomer (functionalized IBR), functionalized styrene / isoprene / butadiene (functionalized SIBR) and elastomers prepared in organic solvent solution coupled with hair tin at least one isoprene and 1,3-butadiene and styrene, with at least one isoprene and 1,3-butadiene, wherein the functional groups of said elastomers are reactive with the hydroxyl groups gives precipitated silica. Rubber composition according to Claim 1, characterized in that said functionalized elastomer is a tin-coupled elastomer prepared by polymerization in organic solvent solution. Rubber composition according to claim 1, further characterized; in that it contains at least one short fiber reinforcing additive or methylene receptor and methylene donor resin product; wherein said methylene donor is comprised of hexamethylenetetramine or hexamethoxymethylmelamine and said methylene receptor is comprised of at least one of resorcinol, resorcinol morbenzoate, phenolic cashew nut resin, polyhydric phenoxy resin and resorcinol resin / reactive formaldehyde. Rubber corinposition according to claim 1, further characterized; in that it contains reinforcing additive comprised of short fibers comprised of at least one of nylon, aramid, polyester, rayon, cellulose and cotton fibers. j j Rubber composition according to any of the preceding claims, characterized in that said non-functionalized diene-based elastomer is comprised of at least one of at least one isoprene and 1,3-butadiene polymers are copolymers and at least one of isoprene and 1,3-butadiene. Rubber composition according to any one of claims 1 to 4, characterized in that said functionalized elastomer contains functional group (s) comprised of: (A) reactive amine functional group with hydroxyl groups on said precipitated silica; or (B) reactive siloxic functional group with hydroxyl groups on said precarious silica. . i, · pinch, or! (C) A combination of reactive amine and siloxy functional groups with the hydroxyl groups superimposed on such precipitated silica! or:. I; (D) a combination of reactive thiol and siloxy functional groups with the hydroxyl groups on said precipitated silica, or (I) a combination of reactive imine and siloxic furttional groups with the hydroxyl groups overrides said precipitated silica, or, - (I) hydroxyl functional groups reactive with said precipitated silica, or pó ': (') (G) hydroxy reactive groups with hydroxyl groups on said precipitated silica, or (H) carboxyl groups reactive with hydroxyl groups on said precipitated silica. 1 ·. I j Rubber composition according to any one of the preceding claims 1 to 4, characterized in that it contains an added silica coupling agent. . j-, f Rubber composition according to Claim 1, characterized in that it contains a combination of prehydrophobized precipitated silica and hydrophilic precipitated silica. . '; wherein said prehydrophobized precipitated silica is hydrophobized prior to its addition. ·:. I '"'. To the rubber composition by treatment with; (·. · · '!' (A) An alkoxysilane, or a combination of an alkoxysilane and at least one of an organoalkoxysilyl and organomercaptoalkoxysilane polysulfide, or I '' (C) at least one of an organoalkoxysilyl and organomercaptoal- 't': 1 '.' 'coxysilane polysulfide. Rubber composition according to claim 8, characterized in that said organoalkoxysilyl polysulfide is comprised of a bis (3-triethoxysilylpropyl) polysulfide having an average of 2 to 4 sulfur bond atoms on their polysulfide bridge. Rubber composition according to claim 9, characterized in that: That said hydrophilic precipitated silica is hydrophobized in situ within the rubber composition by treatment within the rubber composition with: (A) an alkoxysilane, or; | (B) a combination of an alkoxysilane and at least one of an organoalkoxysilyl polysulfide and organomercaptoalcoxysilane, or | · · I. (C) |) is at least one of an organoalkoxysilyl polysulfide and organomercaptoalcoxysilane. j: |