MXPA99002037A - Composition of reinforced rubber with silica and pneumatic with a contact surface with the p - Google Patents

Abstract

This invention relates to a rubber composition and to a tire with a floor contact surface based on the rubber composition prepared with filler reinforcement, a majority of which the silica reinforcement, together with a coupling agent of silica and a minority is carbon black and conventional rubber formulation ingredients, wherein at least one of the liquid formulation and / or coupling agent ingredients is provided deposited in a specified carbon black carrier. In particular, the carbon black carrier is characterized by having a DBP value in a range from about 280 to about 600 cm3 / 100 g and a BET value in a range from about 550 to about 1200 M2 / g. The selection of the carbon black carrier is intended to reduce the resistivity of the electrical volume of the composition of the contact surface with the pi

Description

COMPOSITION OF REINFORCED RUBBER WITH SILICA AND PNEUMATIC WITH SURFACE OF CONTACT WITH THE FLOOR PRODUCED WITH THE SAME FIELD The invention relates to a rubber composition and to a tire with a contact surface of a rubber composition that is substantially reinforced with particulate silica, together with a silica coupling agent and containing only an amount minor carbon black reinforcement. BACKGROUND Rubber compositions, including rubber compositions used for contact surfaces with the tire floor, are sometimes reinforced quantitatively with silica, with only a small amount of carbon black reinforcement. The electrical conductivity of the rubber composition reinforced with silica and rubber is substantially reduced where very low levels of carbon black reinforcement are employed. This reduction in electrical conductivity can be represented, for example, by an increase in volume resistivity of the rubber composition.

Conventionally, a coupling agent is used in conjunction with the silica to couple the silica to the elastomer (s) of the rubber composition.

For liquid coupling agents, a carrier for the coupling agent such as carbon can be employed to introduce it into the rubber composition, wherein the coupling agent and the silica are subsequently combined in situ in the rubber composition. In such a case, the liquid coupler is pre-deposited in the carbon black before mixing it with the rubber composition. The use of carbon black for this carrier and the introduction of the coupler and silica separately in the rubber composition is well known to those skilled in the art. However, the use of relatively low levels of carbon black in the rubber reduces the electrical conductivity of the rubber composition, which may be of interest for a contact surface with the tire floor, where it is convenient that the surface of Contact with the tire floor dissipates the accumulation of static electricity in the tire in a vehicle during use or operation of the vehicle on a road. It is noted that carbon black having a DBP value in a range of about 70 to about 120 cmVlOOg with a corresponding BET value in a range of about 40 to about 159 m / g, ie carbon black designated ASTM N330, is conventionally employed as a carrier for liquid silane-based coupling agents, for silica, particularly where The coupling agent is a liquid bis (trialkoxysilylalkyl) polysulfide. In one aspect of this invention, it is desirable to reduce the volume resistivity of a rubber composition that is quantitatively reinforced with silica and only a minimal amount of carbon black, particularly when the rubber composition is to be used as a contact surface with the floor. This electrical resistivity in volume can be conveniently determined by DIN 53682 or ASTM D257-92 method. Declaration and practice of the invention. According to this invention, there is provided a method for preparing a rubber composition comprising, based on 100 phr of the elastomer (s), mixing (A) 100 phr of at least one diene-based elastomer, (B) of about 35 to about 110, alternately about 40 to about 90 phr of composite reinforcement filler with about 25 to about 100, alternating about 40 to about 80 phr of precipitated silica and correspondingly from about 10 to about 25 total black carbon phr, and (C) about 2 to about 20 phr of a pre-formed compound of specified material and specified carbon black, wherein the material specified is chosen from a liquid rubber formulation ingredient, solid rubber formulation ingredients, preferably a solid formulation ingredient having a melting point lower than 120 ° C or liquid silica coupling agent, which has a reactive portion with silanol groups on the surface of the silica and another interactive portion with the elastomer (s); wherein the liquid and semi-liquid formulation ingredients are chosen from at least one of microcrystalline waxes, antidegradants and accelerators of vulcanization activators; wherein the proportion by weight of the specified material contained in the preformed compound to the specified carbon black liquid of the pre-formed compound is in a range from about 0.5 / 1 to about 3/1; and wherein the carbon black specified has a DBP adsorption value in a range of about 280 to about 600 cm3 / 100 g and a BET value in a range of about 550 to about 1200 m2 / g.

In additional accordance with this invention, there is provided an article of a rubber composition, particularly a sulfur vulcanized rubber composition that is prepared by said method. In further accordance with this invention, there is provided a tire having at least one component, particularly a component vulcanized with sulfur, as a rubber composition prepared by this method. In additional accordance with this invention, there is provided a tire having a floor contact surface, particularly a floor contact surface, vulcanized with sulfur, of a rubber composition prepared by said method. As will be discussed below, it is understood that additional conventional formulation ingredients are mixed with the materials predetermined for the method described, in order to provide a rubber composition, particularly for a tire component such as a contact surface with the floor of the tire. tire. These ingredients typically include materials such as zinc oxide, stearic acid, optional oils and processing waxes, antidegradants, as well as curatives including vulcanization and sulfur accelerators. The structure of components for a tire, including for example a contact surface for a tire, is It molds and vulcanizes under high temperature conditions in a convenient mold to finally produce the tire. This will also be well understood by the person skilled in the art upon becoming familiar with this invention. This rubber formulation philosophy is also readily adaptable for the preparation of various articles of rubber compositions, particularly vulcanized sulfur rubber compositions, which is prepared by the method of this invention as will be understood by a person skilled in the art upon becoming familiar with that invention. The silica coupling agent can be a sulfur-containing organosilicon compound, provided it is liquid at room temperature or about 23 ° C.

Examples of these sulfur-containing organosilicon compounds can be represented by the formula: Z-Alk-Sn-Alk-Z wherein Z is selected from the group consisting of: R 1 R 1 R 2 III - Si - R x - Si - R 2 and - Yes - R2 R "R¿ R ' wherein R1 is selected from alkyl radicals containing from 1 to 4 carbon atoms, cyclohexyl radicals or phenyl radical; R2 is an alkoxy radical containing from 1 to 8 carbon atoms, or a cycloalkoxy radical containing from 5 to 8 carbon atoms; Alk is a divalent hydrocarbon with 1 to 18, preferably 1 to 6, carbon atoms and n is an integer of 2 to 8. Preferably n represents an average value of about 2.1 to about 4, alternately about 2.1 to about 2.5 for a substantially disulfide form of the polysulfide. Therefore, regarding the previous formula, preferably Z is R2 Yes R¿ R2 wherein R2 is an alkoxy radical with 2 to 4 carbon atoms, with 2 carbon atoms, which are particularly preferred; Alk is a divalent hydrocarbon with 2 to 4 carbon atoms, with 3 carbon atoms being particularly preferred; and n is an integer with 2 to 8, preferably represents an average of approximately 2.1 to about 4, alternately from about 2.1 to about 2.5 for the substantial disulfide version of the polysulfide. Preferred sulfur-containing organisilicon compounds are the liquid 3, 3'-bis (trimethoxy or triethoxy silylpropyl) polysulfides having an average of about 2.1 to about 4 or, alternatively, about 2.1 to about 2.5 sulfur atoms in the polysulfide bridge such as for example 3, 3'-bis (tristhoxysilylpropyl) tetrasulfide and 3, 3'-bis (triethoxysilylpropyl) di sulfide. In general, examples of organosilicon polysulfide compounds that can be employed in the practice of this invention include provided they are liquid at 23 ° C, for example: 3, 3'-bis (trimethoxysilylpropyl) disulfide, 3, 3'-bis (triethoxysilylpropyl) tetrasulfide, 3, 3 'bis (triethoxysilylpropyl) octasulfide, 3, 3 'bis (trimethoxysilylpropyl) tetrasulfide, 2, 2 'bis (triethoxysilylethyl) tetrasulfide, 3, 3' bis (trimethoxysilylpropyl) trisulfide, 3,3 'b i s (t r i e t t i t i i i l i t t i i i f i f f 3, 3 'bis (tributoxysilylpropyl) disulfide, 3, 3 'bis (trimethoxysilylpropyl) hexasulfide, 3, 3 'bis (trimethoxysilylpropyl) octasulfide, 3, 3' b i s (t r i o c t ox i s i 1 i 1 p r op i 1) tetrasulfide, 3, 3 'bis (trihexoxysilylpropyl) disulfide, 3, 3'-bis (tri-2"-e t i l h e x o x i s i l i l p ro p i l) t r i s u l f u r o, 3, 3 'bis (triisooctoxysilylpropyl) tetrasulfide, 3, 3 'bis (tri-t-butoxysilylpropyl) disulfide, 2,2' bis (methoxy di etoxi s i l i l et i l) tet rasul f uro, 2, 2 'bis (tripropoxysilylethyl) pentasulfide, 3, 3 'bis (tricyclohexoxysilylpropyl) tetrasulfide, 3, 3 'bis (tricyclopentoxysilylpropyl) trisulfide, 2,2 'bis (tri-2"-methylcyclohexoxysilylethyl) tetrasulfide, bis (trimethoxysilylmethyl) tetrasulfide, 3-methoxy ethoxy propoxysilyl 3'-diethoxybutoxysilylpropyltetrasulfuride, 2, 2 '- i s (dime t i 1 me t oxi s i 1 i le t i 1) disulfide, 2, 2'-bis (dimethyl sec. Butoxysilylethyl) trisulfide, 3, 3'-bis (methyl butylethoxysilylpropyl) tetrasulfide, 3, 3'-bis (di-t-butylmethoxysilylpropyl) tetrasulfide, 2, 2'-bis (phenylmethylmethoxysilylethyl) trisulfide, 3,3'-bis (diphenyl ispoxysilylpropyl) tetrasulfide, 3,3'-bis (diphenyl cyclohexoxysilylpropyl! Disulfide, 3,3'-bis (dimethyl ethylmercaptosilylpropyl) tetrasulfide, 2,2'-bis (methyldimethoxylisi) t il) trisulfide, 2,2'-bis (methyl ethoxypropoxysilylethyl) tetrasulfide, 3,3'-bis (diethylmethoxysilylpropyl) tetrasulfide, 3, 3'-bis (ethyl di-sec. Butoxysilylpropyl) disulfide, 3,3'-bis (propyl diethoxypropyl) disulfide, 3,3'-bis (butyl dimethoxysilylpropyl) trisulfide, 3, 3'-bis (phenyl dimethoxysilylpropyl) tetrasulfide, 3-phenyl-ethoxybutoxysilyl 3'-trimethoxysilylpropyl tetrasulfide, 4,4'-bis (trimethoxysilylbutyl) tetrasulfide, 6, 6 '-bis (triethoxysilylhexyl) tetrasulfide, 12, 12'-bis (triispoxysilyl dodecyl) disulfide, 18, 18 '-bis (trimethoxysilyloctadecyl) tetrasulfide, 18, 18'-bis (tripropoxysilyloctadecenyl) tetrasulfide, 4,4'-bis (t rime toxis il i 1 -buten-2-yl) tetrasulfide, 4, 4'-bis (trimetoxy if lile iclohexyl 1 in) tetrasulfide, 5, 5'-bi s (dime toxymethyl) ilyl) trisulphide, 3, 3'-bis (trimethoxy-silyl-2-methpyl) tetrasulfide, 3, 3'-bis (dimethoxyphenylsilyl-2-methyl-ylpropyl) -sulfide. Representatives of liquid or semiliquid rubber formulation ingredients having a melting point below 120 ° C for example are: 1) microcrystalline waxes such as those commercially available for example as OKERIN 1887 and OKERIN 7950 from Astor Wax Corporation of Titusville, Pennsylvania; 2) antiozoning agents such as those commercially available for example NAUGARD-G from Uniroyal Company (Italy) which can be described as a polymerization product of 1,2-dihydro-2, 2, 6-trimethyl quinoline; 3) antioxidants such as those commercially available for example, WINGSTAYR 100 from The Goodyear Tire & Rubber Company, which can be described as a mixture of aryl-p-phenylene diamine, WLKANOX 3100 from Bayer AG which can be described as a mixture of diaryl-p-phenylene diamine, VULKANOX 4020 from Bayer AG which can be described as N - (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine and SANTOFLEX IPPD from Monsanto Company which can be described as N-phenyl-N '-ispyl-p-phenylene diamine; 4) vulcanization accelerators such as DURAX from R. T. Vanderbilt Company, Inc., which can be described as N-cyclohexyl-2-benzothiazole sulfenamide; AMAX by R. T. Vanderbilt Company, Inc., which can be described as N-oxydiethylene-2-benzothiazole sulfenamide, SANTOCURE DCBS from Monsanto Company which can be described as dicyclohexyl-2-benzothiazole sulfenamide, SANTOCURE NS from the Monsanto Company which can be described as N-tert-butyl-2-benzothiazole sulfenamide, and SANTOGARD PUT from the Monsanto Company and 5) inhibitor of vulcanization such as SANTOGARD PVI from the Monsanto Company which can be described as N-cyclohexylthioftilimide. Liquid and solid (or semi-solid) formulation ingredients that have a softening or spot point Melting at 120 ° C can be applied for example when spraying on carbon black, while those at higher softening points can be applied by organic solvent deposition. A reference for many of these liquid and solid rubber formulation ingredients may for example be The Vanderbilt Rubber Handbook, (Vanderbilt Rubber Manual thirteenth edition (1990, pages 295-395)). A particular dual advantage of using the carbon black carrier prescribed for this invention instead of more conventional carbon blacks is (1) which is considered to be substantially more electrically conductive and thus tends to reduce the electrical resistivity in volume to the rubber composition of this invention for the same amount of carbon black carrier and further (2) because it has a substantially higher DBP absorption value therefore it may be able to adsorb a larger amount of the coupling agent based on silane and in this way be a more efficient carrier. Accordingly, the philosophy is, by using the carbon black specified in accordance with this invention, to provide both a means for improving the electrical conductivity of a rubber composition for contact surface with the reinforced tire floor. with silica quantitatively and also provide a more efficient carrier for the liquid coupling agent. As previously discussed, carbon blacks conventionally employed as a carrier for a liquid coupling agent are not equivalent to the carbon blacks specified for use in this invention in a sense that the two previously used carbon blacks, particularly the black of N330 carbon, have a DBP absorption value, for example in the range of about 100 to about 150 cmJ / 100 g and a BET value, for example in the range of about 40 to about 159 m2 / g. The carbon black N330 has a designated DBP value of approximately 120 cmJ / 100 g and a BET value of approximately 82 m2 / g which is similar to its iodine adsorption value of approximately 82 pr '/ g. Thus, in the practice of this invention, the carbon black required or specified for the liquid formulation ingredient or coupling agent differs substantially from the carbon black carriers in both DBP (dibutylphthalate oil adsorption) and BET (specific surface areas of nitrogen). It is appreciated that the DBP (dibutylphthalate) value can be adequately determined by the ASTM D2414 method and the BET value (nitrogen adsorption) can be conveniently determined by the method described in Journal of the American Chemical Society, Volume 60, page 306 (1930). Representatives of the more conventional carbon black carriers can be for example carbon blacks having an ASTM designation such as N330, which have a DBP value of about 120 cm3 / 100g and a BET value of about 82 m2 / s. Representative examples of carbon blacks contemplated for use as carriers for liquid couplers in the practice of this invention are those such as for example Corax XE-2 from the company Degussa which have a DBP value of approximately 400 c VlOOg and a BET value. about 560 m '/ g, MMM of the 3M having a DBP value of about 300 cmVlOO g and a BET value of about 558 m2 / g, Ketjen EC600J and Ketjen EC300J from the company AKZO, which has a DBP value of about 550 and 360 cmJ / 100 g, respectively and a BET value of approximately 1040 and 800 m / g respectively. Elastomers contemplated for use in this invention are diene-based elastomers such as homopolymers and copolymers of conjugated dienes such as isoprene and 1,3-butadiene and copolymers of these dienes with vinyl aromatic compound such as styrene and / or alphamethylstyrene, preferably styrene. Accordingly, these elastomers, for example, can be cis 1,4-polyisoprene, either natural or synthetic, 3,4-polyisoprene, cis 1,4-polybutadiene, trans 1,4-polybutadiene, high vinyl polybutadiene. which has from about 35 to about 95 percent of 1, 2-vinyl content, isoprene / butadiene copolymers, butadiene / styrene copolymers and styrene / isoprene / butadiene terpolymers. The commonly used siliceous pigments used in rubber formulation applications can be used as the silica in this invention, including precipitated and pyrogenic siliceous pigments (silica) although preferably precipitated silicas. The siliceous pigments preferably used in this invention are precipitated silicas such as, for example, those obtained by the acidification of a soluble silicate, for example sodium silicate. The silicon pigment (silica) can for example have a final particle size in a range of 50 to 10,000 angstroms, preferably between 50 and 400 angstroms. The BET surface area of the pigment, as measured using nitrogen gas, is in a range of about 80 to about 300, although more usually in a range of about 100 to about 200, probably even up to about 360, square meters per gram. The BET method for measuring surface area is described in the Journal of the American Chemical Society, Volume 60, page 304 (1930). The silica typically can have a dibutylphthalate (DBP) absorption value in a range of about 150 to about 350, and usually about 200 to about 300 cmJ / 100 g. The silica may have an average final particle size, for example in a range of about 0.01 to 0.05 mire as determined by the electron microscope, although silica particles may even be smaller in size. Various commercially available silicas can be considered for use in this invention such as, for example, and without limitation, silicas commercially available from PPG Industries under the trademark Hi-Sil with designation 210, 243, etc .; available Rhone-Poulenc silicas such as for example Zeosil 1165MP and silicas available from Degussa AG, with designations such as for example VN2, VN3, BV 3370GR and silicas of J.M Huber company such as, for example, Hubersil 8745.

It is readily understood by those skilled in the art that the rubber composition of the rubber for floor contacting surface will be formulated by methods generally known in the rubber formulation art, such as mixing the various constituent diene polymers vulcanized with sulfur. , with 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 tackifying resins and plasticizers, pigments, fatty acid, zinc oxide , waxes, antioxidants and antiozoning agents, peptizing agents and reinforcing fillers such as for example silica and mixtures of carbon black-silica. As is known to those skilled in the art, depending on the intended use of the compounds vulcanized with sulfur and vulcanizable with sulfur or surface contact compounds with the floor, the aforementioned additives are chosen and commonly used in conventional amounts. Typical additions of carbon black and silica for this invention were previously established. The selection of silica and carbon black type is well within the optimization skill by a person with knowledge in rubber formulation for surfaces of contact with the tire floor, depending on some of the intended use, purposes and properties for the contact surface with the tire floor. Typical amounts of tackifying resins, if employed, comprise about 0.5 to about 10 phr, usually about 1 to about 5 phr. Typical amounts of processing aids comprise about 1 to about 80 phr. These processing aids may include, for example, aromatic, naphthenic, and / or paraffinic or plasticizing oils or polyethylene ether glycols of low softening point. Typical amounts of antioxidants comprise about 1 to about 5 phr. Representative antioxidants for example may be diphenyl-p-phenylenediamine and others such as for example described in The Vanderbilt Rubber Handbook (1978), pages 344-346. Typical amounts of antiozoning agents comprise about 1 to 5 phr. Typical amounts of fatty acids, if employed, which may include stearic acid, comprise about 0.5 to about 4 phr. Typical amounts of zinc oxide comprise about 2 to about 5 phr. Typical amounts of waxes comprise approximately 1 to approximately 5 phr. TO Microcrystalline waxes are often used. Typical amounts of peptizers comprise about 0.1 to about 1 phr. Typical peptizers may for example be pentachlorothiophenol and dibenzamidodiphenyl disulfide. An antioxidant, for example, may be para-phenylene diamine and / or dihydrothrimethylquinoline type. The vulcanization is conducted in the presence of a sulfur vulcanization agent. Examples of suitable sulfur vulcanization agents include elemental sulfur (free sulfur) or vulcanizing agents that donate sulfur, for example an amine disulfide, polymeric polysulfide or defines-sulfur adducts. Preferably, the sulfur vulcanization agent is elemental sulfur. As known to those of skill in the art, sulfur vulcanization agents are employed in an amount in the range of about 0.5 to about 4 phr, with a range of about 1 to about 2.5 being preferred. Accelerators are used to control the time and / or temperature required for vulcanization and to improve the vulcanization properties. Retarders are also used to control the start of vulcanization. In one embodiment, only one accelerator system, i.e. primary accelerator, can be used. From conventionally and preferably, one or more primary accelerators are employed in total amounts in the range of about 0.5 to about 4, preferably about 0.8 to about 2.5, phr. In another embodiment, combinations of a primary and / or a secondary accelerator may be employed, with the secondary accelerator being used in amounts of about 0.05 to about 3 phr, for example in order to activate the cure and improve the vulcanization properties. Suitable types of accelerators that can be employed in the present invention are for example amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, the secondary accelerator is preferably a guanidine, dithiocarbamate or thiuram compound. The selection and amounts of the various formulation ingredients are not considered critical for the purposes of this invention, except when it is emphasized especially elsewhere in this description, and may be adjusted or modified by one who practices as he sees fit for the properties of contact surface with the desired tire floor. The tire can be constructed, shaped, molded and cured by various methods that are known or They are apparent to those with skill in the specialty. The composition of rubber or compounds for the contact surface with the tire floor can be prepared for example by mixing the ingredients in several sequential non-productive stages (without the curatives, sulfur accelerators and associated together with one or more antidegradants at temperatures of approximately 165 ° C followed by a final production mixing stage at a temperature of approximately 105 ° C where the curatives and anti-degradants are added.An internal rubber mixer (Banbury type) is used.The resulting rubber compounds can then be extruded to forming strips of surface contact with the floor which in turn can be built on a tire casing and the resulting structure vulcanized in a convenient mold at a temperature of about 150 ° C to form a tire EXAMPLE I Pre-formed Compounds of a Liquid silica coupler and specified carbon black carrier are prepared by spraying the coupler liquid over granular carbon black at approximately 50 ° C. These compounds were prepared in 3/1 and 1/1 weight proportions of the carbon black coupler. The compounds are illustrated in the following Table 1 and are referred to there as Compound X and Compound Y. Table 1 Compound X Compound Y SY 69J 3 1 23MM2 1 1 1) A liquid 3- (triethoxysilylpropyl) tetrasulfide available from Degussa AG. 2) A carbon black available as 23MM from the company M.M.M., N.V having a BET surface area of approximately 558 m2 / g and a DBP value of approximately 236 ml / g. 3) A compound of the liquid bis-3- (triethoxysilylpropyl) tetrasulfide, available as Si69 from Degussa AG and 23MM of black from the company M.M.M. prepared by spraying liquid tetrasulfide over granular carbon black at approximately 23 ° C. This compound is prepared in a 1/1 weight ratio and a 3/1 weight ratio of liquid tetrasulfide and carbon black. EXAMPLE II Rubber compositions were prepared using the preformed carbon black / coupler compounds of the Example I. The rubber composition employed is illustrated in Table 2 and more detailed additions of silica and silica coupling compounds are illustrated in Table 2. For the rubber composition, the ingredients are first mixed at least one stage of mixed non-productive for approximately 7 minutes at a temperature of approximately 160 ° C. The non-productive mixing steps refer to the mixing of the ingredients without the curatives such as vulcanization and sulfur accelerators. The term "non-productive" mixed is well known to those who have expertise in the specialty. Then, the curatives are mixed in a final mixing step for approximately 2 minutes at a temperature of approximately 120 ° C. Table 2 Non-productive mixing stages Parts E-SBR1 25 Isoprene / Butadiene2 rubber 45 BR3 20 Natural rubber4 10 Processing aids5 25 Fatty acid6 2 Silicaf 'variable Table 2 (Cont.) Non-productive mixing stages Black Parts of Added Carbon7 variable Coupling Agent Compound8 variable Stage of Productive Mixing Sulfur Parts 1 Zinc Oxide 4 Antioxidant (s) 3 Accelerators of the Tiuram and Sulfenamide type 4 1) Emulsion polymerization prepared with SBR that is obtained from The Goodyear Tire & Rubber Company, which has an approximate 40 percent styrene content. 2) Isoprene / butadiene copolymer elastomer having a Tg of about -45 ° C and an isoprene content of about 50 percent which is obtained from The Goodyear Tire & Rubber Company. 3) Cis 1, 4-polybutadiene rubber which is obtained as BUDENEM 1207 from The Goodyear Tire & Rubber Company. 4) Natural rubber (cis 1,4-polyisoprene). 5) Oil processing oil that is approximately 9.4 parts in the E-SBR, where the amount of E-SBR is reported above in dry weight (without the oil) and in addition, approximately 15 parts of additional rubber processing oil, plasticizers, resins and waxes were added. 6) Stearic acid primordially. 7A) N330. 7B) Carbon black 23MM from the company M.M.M. NV. 8) Compounds of bis-3- (triethoxysilylpropyl) tetrasulfide and carbon black. The preformed carbon black / silica coupler compounds are mixed with the rubber composition of Table 2 as illustrated in Table 3. The values are reported in terms of parts by weight to be included in the rubber composition of the Table. 2. Table 3 Exp A. Exp B Exp C Exp D Exp E Ctrl Silica ^ 83 43 43 43 43 X50S 13.28 9 0 0 0 Si69 '4.5 Carbon Black4 6.64 4.5 Carbon Black "0 20 18 24.5 20 Compound X6 0 0 9 0 0 Compound Y7 0 0 0 0 6 Black Total9 6.64 24.5 22.5 24.5 21.5 Table 3 (Cont.) Exp A. Exp B Exp C Exp D Exp E Ctrl Resistivity in electric volume ohm.cm > 1015 > 4 * 103 > 8 * 104 > 2 * 104 > 2 * 10r ' 1) Silica which is obtained as Zeosil 1165MP from Rhone Poulenc Company. 2) A compound constituted by 50/50, by weight of a compound silica coupler as a composition of carbon black N330 and bis-3- (triethoxysilylpropyl) tetrasulfide, commercially available as X50S from Degussa AG. 3) bis-3 - (triethoxysilylpropyl) tetrasulfide liquid which is obtained as Si69 from Degussa AG. 4) The N330 carbon black content included in the X50S which has a BET (nitrogen) value of approximately 80 m / g and a DBP value of approximately 100 ml / 100 g 5) Carbon black added as free carbon black available of the company MMM NV, which has a BET surface area (nitrogen) of approximately 558 m / g and a DBP value of approximately 236 ml / 100 g. 6) Pre-formed compound X of Example I (Table 1) as a silica coupler compound in a weight ratio of 3/1 of bis-3 - (triethoxysilylpropyl) tetrasulfide and 23MM carbon black. 7) Compound Y pre-formed of Example I (Table 1) as a silica coupling compound in a weight ratio l / l of bis-3 - (triethoxysilylpropyl) tetrasulfide and 23MM carbon black. 8) Total amount of carbon black in the rubber composition as the sum of free carbon black added to carbon black contained in the preformed silica couplers. For the control rubber composition (Exp A), approximately 13 phr of a carbon black / pre-formed coupler is used for the rubber composition containing about 6.6 phr of a conventional carbon black (N330). For the Exp B rubber sample, only about 9 phr of the carbon black / conventional preformed coupler is employed with an accompanying amount of about 4.5 phr of carbon black N330 contained therein. However, 20 phr of 23MM carbon black are added to the rubber composition to reduce the electrical resistivity of the rubber composition.

For the rubber composition Exp C, a 23MM carbon black compound / preformed coupler, is used for the aggregate added in a 3/1 ratio (coupler / carbon black) instead of the N330 carbon black / most conventional coupler in a weight ratio 1/1 For Exp D, the coupler and approximately 25 phr of 23MM carbon black were independently added (in-situ) to the rubber composition and no pre-formed carbon black / coupler compound is added. EXAMPLE IV The rubber compositions of Example III are cured for approximately 14 minutes at a temperature of approximately 160 ° C. Various physical properties of the rubber compositions were measured and reported in Table 4 below. Table 4 Exp A Exp Exp B Exp Exp Exp T Ctl T5 (min) 7 6.8 6.8 6.5 7.1 T4U (min) 12 10 10.9 9.8 11.8 Module 30C)% 9 12 11 13 10 (MPa) Traction (; MPa) 16 14 15 13.5 15.7 Table 4 (Cont.) Property Exp A Exp B Exp C Exp D Exp E Ctrl Elongation (%) 590 390 480 340 502 Rebound (100 ° C) 60 55 59 53 61 Rebound (23 ° C) 37 32 37 32 38 Hardness Shore A 67 68 67 69 66 oh. cm1 > 1015 > 4.103 > 8.104 > 2.104 > 2.105 1) Electrical resistance expressed as resistivity in volume (ohm.cm) can be determined by DIN 53682 or ASTM D257-92. - of the rubber composition to be cured for about 14 minutes at a temperature of about 160 °. The total physical properties of the Exp A rubber sample deteriorate somewhat compared to those of the Exp A (Control) rubber sample. The electrical resistance property is significantly reduced at the cost of hysteresis properties. In particular, the values of tensile strength and elongation are lower for sample Exp B.

In general, lower ultimate tensile strength and ultimate elongation for a rubber sample, usually decrease its usefulness somewhat to use as a contact surface of tire that makes contact with the road. In addition, the hysteresis losses, ie the hot and cold rebound values are higher for the rubber sample Exp B, compared to the control sample Exp A. In general, higher hysteresis losses for a rubber compound , can result in superior heat generation in a contact surface with the tire floor, which contacts the road. It can be concluded that the amount of 23MM carbon black added to promote an increase in the electrical conductivity of the rubber composition (as a decrease in its resistivity in volume) favorably for Exp B affects the aforementioned physical properties of the rubber composition in as to its usefulness for a contact surface with the tire floor. The physical properties of the total rubber composition of the Exp C rubber samples show that in combination with the rubber sample of Exp A (control) the strength (tensile and elongation values) and the hysteresis properties (hot rebound values) and cold) deteriorate somewhat but are less than those of the Exp B rubber sample which uses a conventional carbon black / preformed coupler compound. The property of Electrical resistivity was still low enough to discharge static charges. Therefore, it is concluded here that (1) the reduction in total amount of carbon black in the rubber composition is mandatory or essential to achieve the good physical properties of the rubber composition Exp A (control) and also that the use of a 23MM carbon black / pre-formed coupler, acts to substantially reduce the resistivity in electrical volume, as well as reduce the impact on physical properties. The total physical properties of the Exp D rubber samples show that, compared to the rubber sample Exp A (control) if all the carbon black added is carbon black 23 MM, and in the amount used in the rubber composition of Exp B, physical properties are reduced by a greater proportion. The property of electrical resistivity was comparable to Exp B. Therefore, it is concluded here that a minimum amount of carbon black 23MM and carbon black in general, is required in order to achieve satisfactory physical properties such as tensile values, elongation and cold and hot bounce for the rubber composition. For sample Exp E, a pre-formed 23MM carbon black / coupler is used in a 3/1 ratio (coupler / carbon black). Also approximately phr of carbon black 23MM are added to the rubber composition. The total physical properties of the Exp sample E show that, compared to rubber samples Exp A (control), B and C, when all the carbon black is 23MM carbon black and the coupler is used in a ratio of 3: 1 (carbon black to coupler) the properties of this reaction, elongation and rebound in hot and cold, are essentially equivalent to the properties Exp A (control) and in addition, that the electrical resistance is satisfactory. Exp E has the lowest total amount of carbon black. While certain embodiments and representative details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit or scope of the invention.

Claims (32)

1. WHAT IS REFERRED IS: 1. A method for preparing a rubber composition, comprising, based on 100 phr of one or more elastomers, mixing ingredients consisting of (A) 100 phr of at least one elastomer based on diene, (B) about 35 to about 110 phr of reinforcing filler composed of about 25 to about 100 phr of precipitated silica and correspondingly about 10 to about 25 total phr of carbon black, and (C) of about 2 to about 20 phr of pre-formed composite of specified material and specified carbon black, wherein the specified material is chosen from a liquid rubber formulation ingredient, solid rubber formulation ingredient, or liquid silica coupling agent having a reactive portion with silanol groups on the surface of the silica and another interactive portion with the elastomer (s); wherein the liquid and semi-liquid formulation ingredients are chosen from at least one of microcrystalline waxes, antidegradants and vulcanization accelerators and activators, provided that their softening point is less than 120 ° C; wherein the weight ratio of the specified material to the carbon black of the preformed compound is in a range of about 0.5 / 1 to about 3/1; and wherein the carbon black of the compound has a DBP adsorption value in a range of about 280 to about 600 cm 100 g and a BET value in a range of approximately 550 to approximately 1200 m2 / g.
2. 2. The method according to claim 1, wherein the material of the preformed compound is a formulation ingredient.
3. 3. The method according to claim 2, wherein the formulation ingredient has a melting point lower than 120 ° C.
4. 4. The method according to claim 2, wherein the formulation ingredient is selected from one or more microcrystalline waxes, a polymerization product of 1,2-dihydro-2,2,6-trimethyl quinoline, diaryl-p phenylene diamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N-pheni 1-N '- is op r opop i 1 - p - f in i 1 in diamine, N-cyclohexyl- 2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, dicyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide or N-cyclohexylthiophthalimide.
5. 5. The method according to claim 1, wherein the material for the pre-formed compound is a silica coupler such as a 3.3"(trialkoxysilylalkyl) polysulfide having an average of 2 to 4 sulfur atoms in its polysulphide bridge and which is liquid at 23 ° C.
6. 6. The method according to claim 1, wherein the material for the pre-formed compound is a silica coupler selected from at least one of 3, 3'-bis (trimethoxysilylpropyl) polysulfide or 3,3'-bis (triethoxysilylpropyl) polysulfide having an average of about 2.1 to about 4 sulfur atoms in the polysulfide bridge.
7. 7. The method according to claim 5, wherein the silica coupler is 3, 3'-bis (triethoxysilylpropyl) polysulfide having an average of about 3.5 to about 4.0 sulfur atoms in its polysulfide bridge or 3, 3'-bis (triethoxysilylpropyl) having an average from 2.1 to about 2.4 sulfur atoms in its polysulfide bridge.
8. 8. The method according to claim 1, wherein the silica coupler for the pre-formed compound, provided it is liquid at 23 ° C, is selected for example from: 3, 3'-bi s (trimethoxy sili lpropi l) di sul f uro, 3, 3'-bis (triethoxysilylpropyl) tetrasulfide, 3, 3 'bi s (t rietoxi s i l i lpropi l) oct asul f uro, 3, 3 'bi s (trimethoxysilylpropyl) tetrasul furo, 2, 2 'bi s (t reethoxy s i l t i l) t et its l uro, 3, 3' bis (trimethoxysilylpropyl) trisulphide, 3, 3 'bi s (t ri ethoxy s i lprop i l) t r i his f uro, 3, 3 'bi s (t ri but oxi s i l i lprop i l) d i his f uro, 3, 3 'bi s (trimethoxysilylpropyl) hexasul f uro, 3, 3 'bis (trimethoxy s i lpropyl) octasul f uro, 3, 3' bis (trioctoxysilylpropyl) tetrasulfuride, 3, 3 'bis (trihexoxysilylpropyl) disulfide, 3, 3'-bis (tri-2"-e t i l h e x or x i s i l i l p or p i l) t r i s u l f u r o, 3, 3 'bis (triisooctoxysilylpropyl) tetrasulfide, 3, 3 'bis (tri-t-butoxysilylpropyl) disulfide, 2,2' bis (methoxy diethoxy silyl ethyl) tetrasulfide, 2,2 'bis (tripropoxysilylethyl) pentasulfide, 3, 3' bis (tricyclohexoxysilylpropyl) tetrasulfide, 3, 3 'bis (tricyclopentoxysilylpropyl) trisulfide, 2, 2 'bis (tri-2"-methylcyclohexoxysilyletyl) tetrasulfide, bis (trimethoxysilylmethyl) tetrasulfide, 3-methoxy ethoxy propoxysilyl 3'-diethyl oxybutoxypropyl t et rasul f uro, 2, 2'-bis (dimethylmethoxysilylethyl) disulphide, 2,2'-bis (dimethyl) c.bu t oxi si 1 i 1 eti 1) trisulfide, 3, 3'-bis (me ti 1 but i le t oxy Si 1 i lpropi 1) tetrasulfide, 3,3 '-bis (di-t-butylmethoxysilylpropyl) tetrasulfide, 2,2' -bis (phenyl methyl methoxysilylethyl) trisulfide, 3, 3'-bis (dipheni-1 isopropoxysilylpropyl) tetrasulfide, 3, 3 'bis (diphenyl cyclohexoxysilylpropyl) disulphide, 3, 3'-bi s (dimethyl and ilmercaptosilylpropyl) tetrasulfide, 2,2'-bis (methyldimethyl t oxi si 1 i 1 eti 1) trisulfide, 2, 2'-bis (1-ethoxypropoxysilylethyl) tetrasulfide, 3'3'-bis (diethylmethoxysilylpropyl) tetrasulfide, 3'3'-bis (ethyl-diphenyl-butoxysilylpropyl) -disulfide, 3,3'-bis (propyl-diethoxysilylpropyl) -disulfide , 3, 3'-bis (butyl dimethoxysilylpropyl) trisulfide, 3, 3'-bis (phenyl dimethoxysilylpropyl) tetrasulfide, 3-phenyl ethoxybutoxysilyl 3'-trimethoxysilylpropyl tetrasulfide, 4, 4 '-bis (trimethoxysilylbutyl) tetrasulfide, 6, 6'-bis (triethoxysilylhexyl) tetrasulfide, 12, 12 '-bis (t riisopropoxysilyl dodecyl) disulfide, 18, 18'-bis (trimethoxysilyloctadecyl) tetrasulfide, 18,18'-bis (tr ipropoxisi 1 i loct adeceni 1) tetrasulfide, 4,4'-bis (trimethoxysilyl-buten-2-yl) tetrasulfide, 4,4'-bis (trimethoxysilylcyclohexylene) tetrasulfide, 5, 5'-bis (dimethoxymethylsilylpentyl) trisulfide, 3, 3'-bis (trimethoxysilyl-2-methylpropyl) tetrasulfide, or 3,3'-bis (dimethoxyphenylsilyl-2-methylpropyl) disulfide.
9. 9. The method according to claim 1, wherein the diene-based rubber is selected from at least one of synthetic and natural: cis 1,4-polyisoprene, cis 1,4-polybutadiene, trans 1,4-polybutadiene , high vinyl polybutadiene having a content of 1,2-vinyl in a range of about 35 to about 95 percent, of isoprene / butadiene copolymers, butadiene / styrene copolymers and styrene / isoprene / butadiene terpolymers.
10. 10. The method according to claim 1, wherein a preformed carbon black coupler compound and a preformed compound of the carbon black formulation and ingredient is employed.
11. 11. An article constituted by a rubber composition prepared by the method of claim 1.

    12. - An article constituted by a rubber composition prepared by the method of claim 2. 13. - An article constituted by a rubber composition prepared by the method of claim 3. • 14. - An article constituted by a rubber composition prepared by the method of claim 4. 15. An article constituted by a rubber composition prepared by the method of claim 5. 16. An article constituted by a rubber composition prepared by the method of claim 6. 17 An article constituted by a rubber composition prepared by the method of claim 7. 18. - An article constituted by a rubber composition prepared by the method of claim 8. 19. An article constituted by a rubber composition prepared by the method of claim 9. 20. An article constituted by a rubber composition prepared by the method of claim 10. 21.- A tire having a component constituted by a rubber prepared by the method of claim 1. 22. A tire having a contact surface with the floor constituted by a rubber composition prepared by the method of claim 1.

    23. - A tire having a contact surface with the floor constituted by a rubber composition vulcanized with sulfur prepared by the method of claim 1. 24. - A tire having a contact surface with the floor constituted by a rubber composition vulcanized prepared by the method of claim 2. 25.- A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 3. 26.- A tire having a surface of contact with the floor constituted by a vulcanized rubber composition prepared by the method of claim 4. 27.- A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 5. 28.- A tire that has a contact surface with the floor consisting of a vulcanized rubber composition prepared by the method of claim 6. 29.- A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 7. 30.- A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 8.

    31. - A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 9. 32.- A tire having a contact surface with the floor constituted by a vulcanized rubber composition prepared by the method of claim 10. Extract of the Invention COMPOSITION OF REINFORCED RUBBER WITH SILICA AND PNEUMATIC WITH SURFACE OF CONTACT WITH THE FLOOR PRODUCED WITH THE SAME This invention relates to a rubber composition and to a tire with a floor contact surface based on the rubber composition prepared with filler reinforcement, a majority of which the silica reinforcement, together with a Silica coupling agent and a minority is carbon black and conventional rubber formulation ingredients, wherein at least one of the formulation and / or coupling agent ingredients is liquid and is deposited in a specified carbon black carrier . In particular, the carbon black carrier is characterized by having a DBP value in a range of about 280 to about 600 cm '/ 100 g and a BET value in a range of about 550 to about 1200 m2 / g. The selection of the carbon black carrier is intended to reduce the resistivity of the electrical volume of the composition of the contact surface with the floor.