MXPA99007675A - Compositions of rubber containing n- (4-hydroxypenyl) - estearam - Google Patents

Abstract

The present invention relates to: The present invention relates to rubber compositions containing the N- (4-hydroxyphenyl) -stearamide. The presence of ~ N- (4-hydroxyphenyl) -stearamide improves the physical properties of the rubber, which includes the fatigue resistance of flexi

Description

COMPOSITIONS OF RUBBER CONTAINING N - (4-HYDROXYPHENE - ESTEARAMIDE Field of the Invention The present invention relates to a rubber composition containing N- (4-hydroxyphenyl) -stearamide and to the process of rubber compositions containing this N- (4-hydroxyphenyl) -stearamide. BACKGROUND OF THE INVENTION Process auxiliaries are commonly used in rubber compositions, both natural and synthetic. These process aids are used during mixing, which allows the incorporation of fillers and other ingredients quickly with lower energy consumption. In cases where the filler is silica, the well-known organosilicon compounds containing sulfur are used to further assist in the compatibilization of the silica in the rubber composition. SUMMARY OF THE INVENTION The present invention relates to the use of N- (4-hydroxyphenyl) -stearamide in a rubber composition. Detailed Description of the Invention A method for processing a rubber composition is disclosed, which comprises mixing: (i) 100 parts by weight of at least one elastomer, which contains an olefinic unsaturation, selected from the group consisting of natural rubber and homopolymers and copolymers of conjugated dienes and copolymers of at least one conjugated diene and an aromatic vinyl compound; with (ii) from 0.05 to 10 parts per hundred resin (per) of N- (4-hydroxyphenyl) -stearamide. Also disclosed is a rubber composition comprising an elastomer containing an olefinic unsaturation and an N- (4-hydroxyphenyl) -stearamide. The present invention can be used for the process of rubbers or elastomers which contain an olefinic unsaturation. The phrase "rubber or elastomer containing olefinic unsaturation" attempts to include both natural rubber and its various crude and reformed forms, as well as various synthetic rubbers. In the description of this invention, the terms "rubber" and "elastomer" may be used interchangeably, unless otherwise indicated.

The terms "rubber composition", "composite rubber" and "rubber compound", are used interchangeably to refer to rubber which has been combined or mixed with various ingredients and materials and such terms are well known to those skilled in the art of mixing rubber or rubber compositions. Representative synthetic polymers are the products of homopolymerization of butadiene and its homologs and derivatives, for example, methylbutadiene, dimethylbutadiene and pentadiene, as well as copolymers, such as those formed of butadiene or its homologues or derivatives with other unsaturated monomers. Among the latter are acetylenes, for example vinyl acetylene, olefins, for example isobutylene ,. which copolymerizes with the isoprene to form the butyl rubber; vinyl compounds, for example acrylic acid, acrylonitrile (which polymerizes with butadiene to form the NBR), methacrylic acid and styrene, the latter compound polymerizes with butadiene to form the SBR, as do the vinyl esters and various aldehydes unsaturated ketones and ethers, for example acrolein, methyl isopropenyl ketone and vinylethyl ether. Specific examples of synthetic rubbers include neoprene (polychloroprene), polybutadiene (which includes cis-1,4-polybutadiene), polyisoprene (including cis-1,4-polyisoprene), butyl rubber, styrene / isoprene rubber / butadiene, copolymers of 1,3-butadiene or isoprene with monomers, such as styrene, acrylonitrile and methyl methacrylate, as well as ethylene / propylene terpolymers, also known as ethylene / propylene / diene monomer (EPDM) and, in particular, the ethylene / propylene / dicislopentadiene terpolymers. The preferred rubber or elastomer is polybutylene and SBR. In one aspect, the rubber is preferably composed of at least two diene-based rubbers. For example, a combination of two or more rubbers is preferred, such as cis-1,4-polyisoprene (natural or synthetic, although natural is preferred), 3,4-polyisoprene rubber, styrene / isoprene / butadiene rubber, emulsion polymerization and solution, derived from styrene rubbers / butadiene, cis-1,4-polybutadiene rubbers and butadiene / acrylonitrile copolymers prepared by the emulsion polymerization In one aspect of this invention, a styrene / butadiene, derived from emulsion polymerization (E-SBR), can be used with a relatively conventional styrene content of from about 20 to about 28 percent bound styrene or, for some applications, an E-SBR having a medium to relatively high styrene content, i.e., a styrene content united from about 30 to 45 percent. The relatively high styrene content, from about 30 to 45 for the E-SBR, can be considered beneficial for increasing the traction, or slip resistance, of the tread of the rim. The presence of the E-SBR itself is considered beneficial for the purpose of improving the processability of the uncured elastomer composition mixture, especially as compared to the use of an SBR prepared by solution polymerization (S-SBR).

By the E-SBR, prepared by emulsion polymerization, it means that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion, as is well known to those skilled in the art. The content of the bound styrene can vary, for example, from about 5 to 50 percent. In one aspect, the E-SBR may also contain the acrylonitrile to form a terpolymer rubber, such as the E-SBAR, in amounts, for example, from about 2 to 30 weight percent of acrylonitrile attached in the terpolymer. The rubbers of the styrene / butadiene / acrylonitrile copolymer, prepared by the emulsion polymerization, containing about 2 to 40 weight percent of acrylonitrile bound in the copolymer, are also considered as diene based rubbers for use in this. invention. The SBR prepared by the solution polymerization (S-SBR) typically has a styrene content bound in the range of 5 to 50, preferably 9 to 36 percent. The S-SBR can be conveniently prepared, for example, by the catalysis of organic lithium in the presensia of an organic hydrosarbide solvent. One purpose of using the S-SBR is for the improved rolling resistance of the rim,. as a result of lower hysteresis, when used in a tread compound of the rim. The rubber of 3,4-polyisoprene (3,4-PI) is considered beneficial in order to increase the traction of the rim, suando is used in a saddle tread of the tire. The 3,4-PI and its use are dessriben more sompletamente in the patent of E. U. A., No. 5,087,668, which insorpora here so referensia. The Tg refers to the glass transition temperature, the sual can be determined conveniently by a differencial sweeping salorimeter at a burst rate of 10 s per minute. The rubber of 1,4-polybutadiene (BR) is considered benéfiso are in order to improve the wear of the tread of the rim. Such BR can be prepared, for example, by the polymerization of an organic solution of 1,3-butadiene. BR can be conveniently sarasterized, for example, by having at least 90 percent cis-1,4 content. Cis-1-4, oliisoprene and the natural rubber of cis-1,4-polyisoprene are well known to those skilled in the rubber art. The term "per", as used herein and in accordance with conventional practice, refers to "parts by weight of a respective material per 100 parts by weight of rubber or elastomer".

N- (4-hydroxyphenyl) -stearamide, also conosida somo N-stearoyl-p-aminophenyl, is an antioxidant sonoside for polyethylene and polyamides. The N- (4-hydroxyphenyl) -stearamide is a wet powder that has a melting point of 130 to 1342C. The N- (4-hydroxyphenyl) -stearamide, used in the present invention, can be added to the rubber by any conventional tetanus, such as in a mill or in a Banbury mixer. The amount of N- (4-hydroxyphenyl) -stearamide can vary widely, depending on the type of rubber and other mists present in rubber deposition. In general, the amount of N- (4-hydroxyphenyl) -stearamide is used in the approximate range of 0.05 to 10.0 per, are the range of 0.1 to 5.0 psr being preferred. The N- (4-hydroxyphenyl) -stearamide can be added during the non-productive stage or the productive mixing stage, but is preferably added in the non-productive stage. For ease of handling, N- (4-hydroxyphenyl) -stearamide can be used per se or can be deposited on suitable carriers. Examples of carriers that can be used in the present invention include silica, carbon black, alumina, diatomite, silica gel and calsium silicate. In one embodiment, the rubber structure is of a sufficient sanctity of the filling to contribute to a reasonably high modulus and high tear strength. The filling can be added in an amount that varies from 1 to 250 per. When the filler is silica, this silica is generally present in an amount ranging from 10 to 80 per. Preferably, the silica is present in an amount ranging from 15 to 70 per cent. When the filler is carbon black, the amount of this carbon black will vary from 0 to 80 per. Preferably, the amount of carbon black will vary from 0 to 40 per cent. The particulate precipitated silica, commonly used, used in applications of rubber coatings, can be used as such in this invention. These presipitated sylphs include, for example, agüellas obtained by the assidifisation of a soluble sylisate; for example, sodium silisate. Such sylphs can be sarasterized, for example, by having a superfisial BET area, as measured using nitrogen gas, preferably in the approximate range of 40 to 600, and more usually in the approximate range of 50 to 300 meters added per gram. The BET method of measuring the superfisial area is discussed in the Journal of the Amerisan Chemisal Societv, Volume 60, page 304 (1930). The sylise can also be characterized typically by having an absorption value of dibutyl phthalate (DBP) in an approximate range of 100 to 400 and more usually of about 150 to 300. The sylise can be expected to have an average final particle size, for example , in the range of 0.01 to 0.5 microns, as determined by the electron microscope, although the silica particles may be even smaller, or possibly larger, in size. Various commercially available silicas can be considered for use in this invention, such as, for example only, and without limitation, silicas commercially available from PPG Industries, under the trademark of Hi-Sil, with the designations 210, 243, etc.; available silicas of Rhone-Poulens, are, for example, the designations of Z1165MP and Z165GR and available silicas of Degussa AG with, for example, the designations of VN2 and VN3, ets. The process of the vulsanizable rubber is sulfur can be conducted in the presence of an organosilicon compound which contains sulfur. Examples of adosed organosilisium solids which are sulfur are those of the formula: Z - Alq -Sn -Alq - Z (I) in which Z is selected from the group consisting of Rl Rl R2 I Si - R1, - Si - R2 - Si - R2 I R2 R2 R2 where R is an alkyl group with 1 to 4 carbon atoms, cyclohexyl or phenyl; R2 is an alkoxy group with 1 to 8 carbon atoms, or cycloalkoxy with 5 to 8 carbon atoms; Alk is a divalent hydrocarbon with 1 to 18 carbon atoms and n is an integer of 2 to 8. Speci fi c examples of organisium silisium compounds which contain sulfur, suals may be used, according to the present invention, they include: , 3'-bis (trimethoxysilylpropyl), 3,3-bis (triethoxysilylpropyl) tetrasulfide, 3,3-bis (triethoxysilylpropyl) ostasulfide, 3,3'-bis (trimethoxysilylpropyl) tetrasulfide, 3, 3-tetrasulfide * -bis (triethoxysilylpropyl), 3,3'-bis (trimethoxysilylpropyl) trisulfide, 3,3 * -bis (tributylsilylpropyl) disulfide 3,3,3-bis (triethoxysilylpropyl) disulfide, 3,3 * -bis hexasulfide (trimethoxysilylpropyl), 3,3'-bis (trimethoxysilylpropyl) ostasulfide, 3,3'-bis (triostoxysilylpropyl) tetrasulfide, 3,3'-bis (trihexoxysilylpropyl) disulfide, 3,3'-bis trisulfide (tri -2"-ethylhexosisililpropyl), 3,3'-bis (triisoxtosisylpropyl) tetrasulfide, 3,3'-bis disulfide (tri-t- butoxysilylpropyl), 2,2'-bis (methoxy-diethoxy-silyl-ethyl) tetrasulfide, 2,2'-bis (tripropoxysilylethyl) pentasulfide, 3,3'-bis (tricyclohexosisylpropyl) tetrasulfide, 3,3-trisulfide • -bis (tricyclopentoxyisilylpropyl), 2,2 l-bis (tri-2"-methylcyclohexoxysilylethyl) tetrasulfide, bis (trimethoxysilylmethyl) tetrasulfide, 3-methoxy-ethoxy-propoxysilyl-3-diethylbutoxy-silylpropyl tetrasulfide, disulphide 2, 2'-bis (dimethylmethoxysilylethyl), 2,2'-bis (dimethyl-sec-butoxysilylethyl) trisulfide, 3,3 * -bis (methylbutylethoxysilylpropyl) tetrasulfide, 3,3'-bis tetrasulfide (di- t-butylmethoxysilylpropyl), 2,2'-bis ((phenylmethyl-ethoxysilylethyl) trisulfide; 3,3 * -bis (diphenylisopropoxysilylpropyl) tetrasulfide, 3,3'-bis (diphenylsisohexoxysilylpropyl) disulfide, 3, 3 * -bis (dimethylethylmersptosilylpropyl) tetrasulfide, 2,2'-bis (methyldimethoxysilylethyl) trisulfide, tetrasulfide 2,2'-bis (methyletoxipropoxysilylethyl), 3,3 * -bis (diethylmethoxysilylpropyl) tetrasulfide, 3,3'-bis (ethyl-di-seso-butoxysilylpropyl) disulfide, 3,3 * -bis disulfide propyldiethoxysilylpropyl, 3,3'-bis (butyldimethoxysilylpropyl) trisulfide, 3,3'-bis (phenyldimethoxysilylpropyl) tetrasulfide, 3'-trimethoxysilylbutyl) 3-phenyl-ethoxybutoxysilyl tetrasulfide tetrasulfide 4,4'-bis (trimethoxysilylbutyl) , 6, 6 * -bis (triethoxysilylhexyl) tetrasulfide, 12, 12'-bis (triisopropoxysilyl-dodesyl) disulphide, 18,18'-bis (trimethoxysilylostadesyl) tetrasulfide, 18,18'-bis tetrasulfide (tripropoxysilyl) -desenyl) , tetrasulfide of 4,4 * -bis (trimethoxysilyl-buten-2-yl), tetrasulfide of 4,4 '-bis (trimethoxy) silylsislohexylene), 5,5'-bis (dimethoxymethylsilylpentyl) trisulfide, 3,3'-bis (trimethoxysilyl-2-methylpropyl) tetrasulfide, and 3, 3'-bis (dimethoxyphenylsilyl-2-methylpropyl) disulfide. Preferred siliconium silicate structures which are sulfur, of Formula II, are the sulfides of 3,3'-bis (trimethoxy- or triethoxy-silylpropyl). The most preferred compound is 3, 3'-bis (triethoxysilylpropyl tetrasulfide and 3,3'-bis (triethoxysilylpropyl) disulfide. Therefore, for Formula I, preferably Z is: - Si - R where R2 is an alkoxy group with 2 to 4 carbon atoms, with 2 carbon atoms being particularly preferred; Alk is a divalent hydrocarbon with 2 to 4 carbon atoms, particularly preferably with 3 carbon atoms; and n is an entity from 3 to 5, with 4 being particularly preferred. The amount of the organic silicon compound containing sulfur in a rubber composition will vary depending on the level of silica used. Generally speaking, the sanctity of the formula of formula II, if used, will vary from 0.1 to 1.0 parts by weight per part by weight of the syllable. Preferably, sanctity will vary from 0.05 to 0.4 parts by weight per part by weight of the silica. The rubber compositions of the present invention may contain a methylene donor and a methylene aseptide. The term "methylene donor" is intended to mean a ready-to-go solution is a methylene acceptor (such as resorcinol or its equivalent, which contains a hydroxyl group present) and generate the resin in situ. Examples of methylene donors which are suitable for use in the present invention include hexamethylenetetramine, hexaethoxymethylmelamine, hexametoxymethylmelamine, lauryloxymethylpyridinium chloride, ethoxymethylpyridinium chloride, trioxan-hexametoxymethylmelamine, whose hydroxy groups can be esterified or etherified parasially, and polymers of formaldehyde, such as paraformaldehyde. In addition, the methylene donors may be N-substituted oxymethylmelamines of the general formula: wherein X is an alkyl having from 1 to 8 sarbono atoms, R3, R4, R5, R6 and R7 are individually selected from the group consisting of hydrogen, an alkyl is from 1 to 8 atoms of sarbon and the group -CH2OX . Methylene donors thickeys include hexakis- (methoxymethyl) melamine, N, N ', N "-trimethyl / N, N', N" -trimethylolmelamine, hexamethylolmelamine, N, N ', N "-dimethylolmelamine, N-methylolmelamine, N , N'-dimethylolmelamine, N, N ', N "-tris (methoxymethyl) melamine and N, N', N" -tributyl-N, N ', N "-trimethylol-melamine. The N-methylol derivatives of melamine are prepared by sonoside methods. The sanctity of the methylene donor and the methylene acceptor, which is present in the rubber material, can vary. Typically, the amount of the methylene donor and the methylene acceptor present will vary in the approximate range of 0.1 to 10.0 per. Preferably, the amount of the methylene donor and the methylene acceptor vary in ranges of about 2.0 to 5.0 psr, each. The weight ratio of the methylene donor to the methylene acceptor can vary. Generally speaking, the weight ratio will vary from approximately 1:10 to 10: 1.

Preferably, the weight ratio will vary from about 1: 3 to 3: 1. It will be readily understood by those skilled in the art that rubber deposition will be obtained by methods generally employed in the rubber dispensing process, such as the mixture of several solid rubbers, which can be vulsified are sulfur, are various commonly used additive materials. . As is known to those skilled in the art, depending on the intended use of the vulsanized material are sulfur and can be vulsified are sulfur (rubbers), the additives, mentioned below, are commonly selected and used in conventional amounts. Representative examples of sulfur donors include elemental sulfur (free sulfur), an amino disulfide, polymeric polysulfide and sulfur olefin adducts. Preferably, the sulfur vulcanizing agent is elemental sulfur. This sulfur vulcanizing agent can be used in an amount ranging from 0.5 to 8 per, with a range of 1.5 to 6 per being preferred. Typical amounts of process oils comprise approximately from 1 to 50 per. Such processing aids may include, for example, aromatic, naphthenic and / or paraffinose process oils. Typical amounts of antioxidants comprise approximately 1 to 5 per. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others such as, for example, stems described in The Vanderbilt Rubber Handbook (1978), pages 344-346. Typical amounts of antiozonants are approximately 1 to 5 psr. Typical amounts of fatty acids, if used, which may include the stearic acid, may be approximately 0.5 to 3 psr. Typical amounts of zin oxide are approximately 2 to 5 psr. Typical amounts of microcrystalline and paraffin waxes comprise about 1 to 10 per. Often, microcrystalline waxes are used. Typical amounts of peptizers, when used, comprise about 0.1 to 1 per. Typical peptizers may be, for example, pentachlorothiophenyl and dibenzamidodiphenyl disulfide. In one aspect of the present invention, the vulcanizable rubber composition of sulfur is then cured or vulcanized with sulfur. Accelerators are used to control the time and / or temperature required for vulcanization and to improve the vulcanization properties. In one embodiment, a simple accelerator system, that is, a primary accelerator, can be used. The primary accelerators can be used in total amounts ranging from about 0.5 to 4, preferably about 0.8 to 1.5 per. In another embodiment, combinations of a primary and secondary accelerator can be used with the secondary accelerator being used in amounts of approximately 0.05 to 3 per, in order to activate and improve the vulcanization properties. Combinations of these accelerators can be expected to produce an efesto synergism in the final properties and are somewhat better than those produced by the use of their individual reactors alone. further, delayed assimilators can be used that do not affect normal process temperatures, but produce a satisfactory cure at ordinary vulcanization temperatures. Vulsanization retarders can also be used. Suitable types of accelerators that may be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates. Preferably, the primary accelerator is a sulfenamide. If a second accelerator is used, this secondary accelerator is preferably a compound of a guanidine, dithiocarbamate or thiuram. The mixture of the rubber composition can be accomplished "by methods known to those skilled in the art of mixing rubber methods. For example, the ingredients are typically mixed in at least two stages, it is desir, at least one non-productive stage followed by a productive mix stage. the final curatives are typically mixed in the final stage which is conventionally named stage "productive" mix where at a temperature, or ultimate temperature, lower than the temperature of this mixture occurs traditionally The mixture, in comparison, is the preceding nonproductive mixture (s) etap (s) The rubber and the N- (4-hydroxyphenyl) -stearamide are mixed in one or more non-productive mixing stages. The terms of "non-productive" and "productive" mixing stages are well known to those skilled in the art of rubber mixing.The rubber composition containing N- (4-hydroxyphenyl) -stearamide, rubber, silica and compound of organosilicon that Contains sulfur, if used, it can be subjected to a thermomechanical mixing stage. This thermomechanical mixing step generally comprises mechanical work in a mixer or extruder, for a suitable period of time, in order to produce a rubber temperature between 140 and 190se. The appropriate duration of thermo-ecological work varies as a function of the operating conditions and the volume and nature of the components. For example, the thermomechanical work can be from 4 to 20 minutes. The vulcanization of the rubber composition of the present invention is generally carried out at conventional temperatures ranging from about 100 to 200SC. Preferably, the vulcanization is conducted at temperatures ranging from 110 to 180 ° C. Any of the usual vulcanization processes can be used, such as heating in a press or mold, heating with superheated steam or hot air or in a salt bath. In the vulcanization of the composition vulcanized with sulfur, the rubber composition of this invention can be used for various purposes. For example, the rubber composition vulcanized with sulfur can be in the form of a rim, band or hose. In the case of a tire, it can be used for various components of the tire. These rims can be constructed, shaped, molded and cured by various methods, which are known and readily apparent to those skilled in the art. Preferably, the rubber composition is used in the tread of the rim. As can be seen, the rim can be a rim of a passenger vehicle, airplane, truck and the like. Preferably, the rim is a rim of a passenger vehicle. This rim can also be radial or oriented, with the radial rim being preferred. The invention can be better understood with reference to the following examples, wherein the parts and percentages are by weight, unless otherwise indicated.

The following examples are presented in order to illustrate, but not limit, the present invention. The surasin properties were determined using a disso ossilator rheometer Monsanto, the sual was operated at a temperature of 150 se and a fresuensia of 11 hertz. A dessripsión of the disso ossilador rheometers can be found in the Vanderbilt Rubber Handbook, edited by Robert O. Ohm (Norwalk, Conn., R. T. Vanderbilt Company, Ins., 1990), pages 554-447. The use of this surasion meter and the standardized values read from the surva are specified in the ASTM D-2084 standard. A typical suva surva, obtained in a disso ossilator rheometer, is shown on page 555 of the 1990 edition of the Vanderbilt Rubber Handbook. In such a disso ossilator rheometer, the rubber samples were subjected to a sorting ossilator assassination of constant amplitude. The torsion of the disso ossilator embedded in the material under test, required to ossulate the rotor at the vulsanization temperature, was measured. The values obtained using this healing test are very significant, since the changes in the rubber or the formulation of composition are very easily detected. It is obvious that it is usually advantageous to have a rapid healing regime.

The invention can be better understood with reference to the following examples, in which the parts and percentages are by weight, unless otherwise indicated.

Example 1 Preparation of N-.4-hydroxyphenyl) -estearamide A 3-liter flask was charged with 218 grams (2 moles) of 4-aminophenyl, 538 grams (1.9 moles) of stearic acid, 20 grams of p-toluenesulfonic acid 300 ml of xylene and was flushed with nitrogen. This flask was equipped with a Dean-Stark trap for water removal and the sonnets were heated, with agitation, at 220 ° C, and water and xylene were removed for 2 hours. Twenty-one milliliters of water were removed. The flask flasks were cooled to 1102C and were floated in a polyethylene filtrate, the sual was separated from volatile materials at 125-130 SC to a 73.66 cm Hg vessel, to give 737 grams of a waxy solid are a thickened infrared thickener. which shows the phenomenal and amide functional groups.

Example 2 In this example, various levels of N- (4-hydroxyphenyl) -stearamide were evaluated in a rubber compound.

Rubber compositions which are the materials indicated in Tables 1 and 2, were prepared in a Banbury ™ BR mixer, using two separate stages of adtion (mixing); that is, the non-productive mixing stage and a stage of produstive mixing. The non-productive stage was mixed for up to 4 minutes or at a rubber temperature of 160 ° C, whichever comes first. The mixing time for the productive stage was at a rubber temperature of 110se for 2 minutes. Rubber sompositions were identified here as Samples 1-4. Sample 1 is considered as a control, without the use of any N- (4-hydroxyphenyl) -stearamide added to the rubber composition. Others besides the level of the turpentine and the N- (4-hydroxyphenyl) -stearamide, all the rubberiness, were the same. The samples were swept at about 150 ° C for about 36 minutes. Table 2 illustrates the behavior and physical properties of the cured samples 1-4. It is clearly evident from the results that the use of N- (4-hydroxyphenyl) -stearamide in the rubber compound provides a lower minimum torque of the rheometer, which indicates less work input required during Banbury mixing and an improved compound of the process. N- (4-hydroxyphenyl) -stearamide also provided 13 properties Improved bending, as measured by the Cut Growth test. The reduced DIN abrasion suggests that there is an improvement in the wear of the tread on a rim. Table 1 commercially from The Goodyear Tire & Rubber Company as PLF 1502.? Carbon black N299. 3 Aromatic oil, waxes, tackifier 4 N-phenyl-N '- (1,3-dimethylbutyl) -p-phenylenediamine 5 Diaryl-p-phenylenediamine mixed. 6 Types of sulfenamide Table 2 - "• ASTM D-395 2 2 PPrruueebbaa CCuutt Growth described in Rubber Chem &Tech, September-October 1990, volume 53, Bo.4, pages 567-581.

While e have shown certain representative modalities and details 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 (9)

1. CLAIMS 1. A method for the process of a rubber composition, the sual is sarasterized because it is mixed: (i) 100 parts by weight of sudo less an elastomer, which are an olefinised instauration, selessionate of the group that is the natural rubber and homopolymers and sopolymers of conjugated dienes and copolymers of at least one conjugated diene and an aromatic vinyl compound; with (ii) from 0.05 to 10 parts per hundred resin (psr) of N- (4-hydroxyphenyl) -stearamide.
2. 2. The method of claim 1, which is freeze-dried, is present from 0.1 to 10 psr of a methylene donor in the rubber composition, and this methylene donor is selected from the group consisting of hexamethylenetetramine, hexaethoxymethylmelamine, hexametoxymethylmelamine, slurry lauryloxymethylpyridinium, ethoxymethylpyridinium slurium, trioxan-hexametoxymethylmelamine, their hydroxy groups can be esterified or parsially etherified, formaldehyde polymers and N-substituted oxymethylmelamines, of the general formula: wherein X is an alkyl having from 1 to 8 sarbono atoms, R3, R4, R5, R6 and R7 are individually selected from the group that hydrogen is an algane are 1 to 8 atoms of sarbon and the group -CH2OX .
3. 3. The method of claim 1, sarasterized by the elastomer, which contains the olefinised unsaturation is selected from the group of natural rubber, neoprene, polyisoprene, butyl rubber, polybutadiene, ethylene-butadiene copolymer, styrene / isoprene rubber / butadiene, methyl methacrylate-butyiene copolymer isoprene-styrene copolymer, methyl methacrylate-isoprene copolymer, acrylonitrile-isoprene copolymer, acrylonitrile-butadiene copolymer, EPDM, and mixtures thereof.
4. 4. A rubber composition, sarasterized by an elastomer which contains an olefinic unsaturation and 0.05 to 10 per cent of the N- (4-hydroxyphenyl) -estealamide.
5. 5. The composition of claim 4, characterized in that it is present from 0.1 to 10 per of a methylene donor in the rubber composition, and this methylene donor is selected from the group consisting of hexamethylenetetramine, hexaethoxymethylmelamine, hexametoxymethylmelamine, lauryloxymethylpyridinium, ethoxymethylpyridinium chloride, trioxan-hexametoxymethylmelamine, whose hydroxy groups can be esterified or partially etherified, formaldehyde polymers and N-substituted oxymethylmelamines, of the general formula: in which X is an alkoyl having from 1 to 8 carbon atoms, R, R, R5, R6 and R7 are individually selected from the group consisting of hydrogen an alkenyl having 1 to 8 carbon atoms and the group -CH2OX .
6. 6. The somposision of claim 4, sarasterized because the elastomer, which is olefinised unsaturation, is selected from the group of natural rubber, neoprene, polyisoprene, butyl rubber, polybutadiene, ethylene-butadiene copolymer, styrene / isoprene / butadiene rubber , methyl methacrylate-butylene copolymer isoprene-styrene copolymer, methyl methacrylate-isoprene copolymer, acrylonitrile-isoprene copolymer, asyronitrile-butadiene sopolymer, EPDM, and their mixtures.
7. 7. A sulfur vulcanized rubber composition, which is characterized in that it is prepared by heating the composition of claim 4, at a temperature ranging from 100 to 2002C, in the presence of a sulfur vulcanizing agent.
8. 8. The rubber composition vulcanized with sulfur, according to claim 7, characterized by being in the form of a rim, band or hose.
9. 9. A rim, which has a tread characterized by the composition according to claim 8.