MXPA99006987A - Pneumatic rim that has a bearing band containing res - Google Patents

Abstract

The present invention relates to: A pneumatic rim, having a tread, characterized by (a) an elastomer based on a diene, containing olefinic unsaturations and (b) from 1 to 50 parts per hundred resin (pcr) of a polymeric resinous material, comprising from 4 to 60 weight percent of units derived from piperylene, from about 10 to 35 weight percent of units derived from 2-methyl-2-butene and from 18 to 50 percent by weight. percent in weight of units derived from the diciclopentadie

Description

PNEUMATIC RIM THAT HAS A BEARING BAND CONTAINING RESIN BACKGROUND OF THE INVENTION Polymer resins have been used in tire treads to improve traction. Unfortunately, a consequence of its use is a decrease in the durability and use of the tread. Units containing polymeric resinous materials, piperylene derivatives, units derived from 2-methyl-2-butene and units derived from dicyclopentadiene are commercially available from The Goodyear Tire & Rubber Company, under the designation of WINGSTACK® 115. These polymeric resinous materials find use in adhesives.

SUMMARY OF THE INVENTION The present invention relates to a pneumatic rim having a tread band containing a rubber and from 1 to 50 parts per hundred resin (per) of a polymer resinous material.

Detailed Description of the Invention A pneumatic tire having a tread is disclosed which contains: (a) an elastomer based on diene, containing olefinic unsaturations and (b) from 1 to 50 per of a polymeric resinous material comprising from 4 to about 60 weight percent of units derived from piperylene, from about 10 to 35 weight percent of units derived from methyl-2-butene and from 18 to 50 weight percent of units derived from dicyclopentadiene. The resinous material, for use in the present invention, comprises about 4 to 60 percent of units derived from piperylene, about 10 to 35 weight percent of units derived from 2-methyl-2-butene and about 18 to 50 weight percent of units derived from dicyclopentadiene. Preferably, the resin comprises about 30 to 55 percent by weight of piperylene, about 15 to 25 percent by weight of 2-methyl-2-butene and about 20 to 45 percent by weight of dicyclopentadiene. The polymeric resin for use in the tread of a rim is dispersed in a diene-based elastomer in an amount ranging from about 1 to 50 per cent. Preferably, the polymer resin is present in an amount ranging from 20 to 40 per cent. The resins can be prepared using various anhydrous metal halide catalysts. Representative examples of such catalysts are fluorides, chlorides and bromides, of aluminum, tin and boron. These catalysts include, for example, aluminum chloride, stannic chloride and boron trifluoride. Alkyl aluminum dihalides are also suitable, representative examples of which are methyl aluminum dichloride, ethyl aluminum dichloride and isopropyl aluminum dichloride. In carrying out the polymerization reaction, the hydrocarbon mixture is contacted with the anhydrous halide catalyst. Generally, the catalyst is used in particulate form, having a particle size in the approximate range of a mesh of 5 to 200, although larger or smaller particles can be used. The amount of the catalyst used is not critical, although sufficient catalyst must be used to cause the polymerization reaction to occur. The catalyst can be added to the olefinic hydrocarbon mixture or this mixture of hydrocarbons can be added to the catalyst. If desired, the catalyst and the hydrocarbon mixture can be added simultaneously or intermittently to the reactor. The reaction can be conducted continuously or by the batch process technique, generally known to those skilled in the art. The reaction is conveniently carried out in the presence of a diluent, because it is usually exothermic. Several diluents that are inert, since they do not enter the polymerization reaction, can be used.

Representative examples of inert diluents are aliphatic hydrocarbons, such as pentane, hexane and heptane, aromatic hydrocarbons such as toluene and benzene., and unreacted residual hydrocarbons from the reaction. A wide range of temperatures can be used for the polymerization reaction. The polymerization can be carried out at temperatures in the approximate range of -20 to 100 ° C, although usually the reaction is carried out at a temperature in the range of about 0 to about 50 ° C. The pressure of the polymerization reaction is not critical and can be atmospheric or above or below this atmospheric pressure. In general, a satisfactory polymerization can be conducted when the reaction is carried out around the autogenous pressure, developed by the reactor under the operating conditions used. The reaction time is not generally critical and these reaction times may vary from a few seconds to 12 hours or more. Upon completion of the reaction, the hydrocarbon mixture is neutralized, followed by the isolation of the resin solution. The resin solution is distilled with the resulting resin material, allowing it to cool. The resins may, optionally, be modified by the addition of up to 25 weight percent of the piperylene dimers or trimers of piperylene or other unsaturated hydrocarbons, particularly hydrocarbons containing from 4 to 6 carbon atoms, and mixtures thereof, the mixture of piperylene / 2-methyl-2-butene / dicyclopentadiene. Representative examples of such hydrocarbons are butene and substituted butenes, such as 2-methyl-1-butene, 2,3-di-methyl-1-butene, 2, 3-dimethyl-2-butene, 3,3- dimethyl-l-butene; the pentenes and substituted pentenes, such as 1-pentene, 2-pentene, 2-methyl-1-pentene, 2-methyl-2-pentene, 3-methyl-2-pentene, 4-methyl-1-pentene, 4 -methyl-2-pentene; hexenes, such as 2-hexenm; diolefins, such as 1,3-butadiene and isoprene; and cyclic unsaturated hydrocarbons, such as cyclopentene, cyclohexane and 1,3-cyclopentadiene. The resinous materials of this invention are characterized by having a Gardner color of about 2 to 10, a softening point of about 100 to 160dC, according to the method of ASTM E28, good heat stability and a specific gravity of about 0.85 to 1.0. They typically have a softening point of 100 to 1402C after separation with water vapor, to remove the lower molecular weight compounds; although, when prepared in the presence of a chlorinated hydrocarbon solvent, its softening point is increased from about 100 to 160ac. These resins are generally soluble in aliphatic hydrocarbons, such as pentane, hexane, heptane, and aromatic hydrocarbons, such as benzene and toluene. The tread of the rim of the present invention contains an elastomer that includes an olefinic unsaturation. The phrase "rubber or elastomer containing olefinic unsaturations" 11 attempts to include both natural rubbers with their various crude and reformed forms, as well as various synthetic rubbers In the description of this invention, the terms "rubber" and "elastomer" can be used interchangeably, unless otherwise indicated The terms "rubber composition", "composite rubber" and "rubber compound" are used interchangeably to refer to rubber that has been mixed or combined with various ingredients and materials, and such terms are well known to those skilled in the art of rubber mixing or rubber composition Representative synthetic polymers are the homopolymerization products of butadiene and its homologues and derivatives, for example methybutadiene, dimethylbutadiene and pentadiene. , as well as copolymers such as those formed of butadiene or its homologs or derivatives with other unsaturated monomers. The acetylenes are found, for example acetylene vinyl; olefins, for example isobutylene, which copolymerize with isoprene to form butyl rubber; vinyl compounds, for example, acrylic acid, acrylonitrile (which polymerizes with butadiene to form NBR), methacrylic acid and styrene, the latter compound polymerizes with butadiene to form the SBR, like vinyl esters and various aldehydes ketones and unsaturated ethers, for example acrolein, methyl isopropenyl ketone and vinylethyl ether. Specific examples of synthetic rubbers include neoprene (polychloroprene), polybutadiene (which includes cis-1, 4-polybutadene), 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, ethylene / propylene / dicyclopentadiene terpolymers. The preferred rubber or elastomers are polybutadiene and SBR. In one aspect, the rubber is preferably 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 / butadiene rubbers, cis-1, 4-polybutadiene rubbers and butadiene / acrylonitrile copolymers prepared by emulsion polymerization In one aspect of this invention, a styrene / butadiene, derivative of emulsion polymerization (E-SBR), it 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 bound styrene content of 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, of 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 bound styrene content 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 presence of an organic hydrocarbon 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 tire tread composition. The rubber of 3,4-polyisoprene (3,4-PI) is considered beneficial in order to increase the traction of the rim, when used in a tread composition of the rim. 3,4-PI and its use are described more fully in the patent of E. U. A., No. 5,087,668, which is incorporated herein by reference. The Tg refers to the glass transition temperature, which can be conveniently determined by a differential scanning calorimeter at a heating rate of 10 ° C per minute. The rubber of 1,4-polybutadiene (BR) is considered beneficial 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. The BR can be conveniently characterized, for example, by having at least 90 percent cis-1,4 content. Cis-l-4, polyisoprene and the natural cis-1,4-polyisoprene rubber 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". In one embodiment, the rubber composition must contain a sufficient amount of the filler having individual aggregates containing different particle sizes to contribute 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 cent. 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 precipitated particulate silica, commonly used, used in rubber compound applications, can be used as the silica in this invention. These precipitated silicas include, for example, those obtained by the acidification of a soluble silicate; for example, sodium silicate. Such silicas can be characterized, for example, by having a BET surface 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 square meters per gram. The BET method of measuring surface area is described in the Journal of the American Chemical Society. Volume 60 page 304 (1930). The silica can also typically be characterized as 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 silica 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 from Rhone-Poulenc, with, for example, the designations of Z1165MP and Z165GR and silicas available from Degussa AG with, for example, the designations VN2 and VN3, etc. The rubber process vulcanizable with sulfur can be conducted in the presence of an organosilicon compound containing sulfur. Examples of suitable sulfur-containing organosilicon compounds are those of the formula: Z - Alq -Sn -Alq - Z (I) in which Z is selected from the group consisting of R1 R1 R2 I I I - Si - R1, - Si - R2 and - Si - R2 I I 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. Specific examples of sulfur-containing organic silicon compounds, which may be used, according to the present invention, include: disulphide 3; 3 --bis (trimethoxysilylpropyl) tetrasulfide, 3,3 --bis (triethoxysilylpropyl) octasulfuro 3,3 '-bis (triethoxysilylpropyl) tetrasulfide, 3,3'-bis (trimethoxysilylpropyl) tetrasulfide 3.3 '-bis (triethoxysilylpropyl), 3,3'-bis (trimethoxysilylpropyl) trisulfide, 3,3'-bis (triethoxysilylpropyl) disulfide trisulfide 3,3'-bis (tributoxysilylpropyl) disulfide, 3,3'-bis hexasulfide (trimethoxysilylpropyl) octasulfuro 3,3 '-bis (trimethoxysilylpropyl) tetrasulfide, 3,3'-bis (trioctoxisililpropilo) disulfide, 3,3'-bis (trihexoxisililpropilo) trisulfide, 3,3'-bis (tri -2"-ethylhexosisililpropyl), 3,3'-bis (triisoxoctoxysilylpropyl) tetrasulfide, 3,3'-bis (tri-t-butoxysilylpropyl) disulfide, t 2,2'-bis (methoxy-diethoxy-silyl-ethyl) ethersulfide, 2,2'-bis (tripropoxysilylethyl) pentasulfide, 3,3'-bis (tricyclohexosisylpropyl) tetrasulfide, 3,3'-bis trisulfide (triciclopentoxiisililpropilo) tetrasulfide, 2,2'-bis (tri-2"-metilciclohexoxisililetilo) tetrasulfide, bis (trimetoxisililmetilo) tetrasulfide, 3-methoxy-ethoxy-3-propoxisilil • -dietoxibutoxi- silylpropyl disulfide 2.2 '-bis (dimethylmethoxysilylethyl), 2,2'-bis (dimethyl-sec-butoxysilylethyl) trisulfide, 3,3'-bis (methylbutylethoxysilylpropyl) tetrasulfide, 3,3'-bis (di-t-butylmethoxysilylpropyl tetrasulfide ), 2,2'-bis ((phenylmethyl-methoxysilylethyl) trisulfide; tetrasulfide, 3,3'-bis (difenilisopropoxisililpropilo) disulfide, 3,3'-bis (difenilciclohexoxisililpropilo), 3.3 tetrsulfuro --bis (dimetiletilmercptosililpropilo) trisulfide, 2, 2 '-bis (etildimetoxisililetilo) tetrasulfide 2,2'-bis (ethylexypropoxysilylethyl), 3,3'-bis (diethylmethoxysilylpropyl) tetrasulfide, 3,3'-bis (ethyl-di-sec.-butoxysilylpropyl) disulfide, 3,3'-bis disulfide ( propildietoxisililpropilo trisulfide, 3,3'-bis (butildimetoxisililpropilo) tetrasulfide, 3,3'-bis (fenildimetoxisililpropilo), 3 '-trimetoxisililbutulo) -tetrasulfide 3-phenyl- 4,4 --bis etoxibutoxisililo tetrasulfide (trimetroxisililbutilo) tetrasulfide, 6,6 - bis (trietoxisililhexilo) disulfide, 12,12'-bis (triisopropoxysilyl-dodecyl) tetrasulfide l8,18'-bis (trimetoxisililoctadecilo) tetrasulfide, 18,18'-bis (tripropoxisililoctadecenilo) , tetrasulfide of 4,4'-bis (trimethoxysilyl-buten-2-yl), tetrasulfide of 4,4, -bis (trimethoxysilylcyclohexylene) , 5,5'-bis (dimethoxymethylsilylpentyl) trisulfide, 3,3'-bis (trimethoxysilyl-2-methylpropyl) tetrasulfide, and 3,3'-bis (dimethoxyphenylsilyl-2-methylpropyl) disulfide. Preferred sulfur-containing organic silicon compounds of the 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: R2 I - Yes - R2 I R2 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 integer 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 amount of the compound of formula II, if used, will vary from 0.1 to 1.0 parts by weight per part by weight of the silica. Preferably, the amount 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 acceptor. The term "methylene donor" is intended to mean a compound capable of reacting with a methylene acceptor (such as resorcinol or its equivalent, containing a hydroxyl group present) and generating the resin in situ. Examples of methylene donors which are suitable for use in the present invention include hexamethylenetetramine, hexaetoximetilmelamina, hexamethoxymethylmelamine, lauryloxymethylpyridinium chloride, ethoxymethylpyridinium chloride, trioxan hexamethoxymethylmelamine-, whose hydroxy groups may be esterified or partly etherified, 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 carbon atoms, R3, R4, R5, R6 and R7 are selected, individually, from the group consisting of hydrogen an alkyl having 1 to 8 carbon atoms and the group -CH2OX . Specific methylene donors include hexakis- the (methoxymethyl) melamine, NN ,, N "-trimethyl / N, N ', N" -trimetilolmelamina, hexamethylolmelamine, N, N', N "-dimetilolmelamina, N-metilolmelmina, N, N '-dimethylolmelamine, N, N', N "-tris (methoxymethyl) melamine and N, N ', N" -tributyl-N, N', N "-trimethylol-melamine. The N-methylol derivatives of the melamine are prepared by known methods. The amount 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 from about 2.0 to 5.0 per, 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 is readily understood by those skilled in the art that the rubber composition mixing various constituent rubbers which can be vulcanized with sulfur, with various additives used materials will be obtained by methods generally known in the art of compounding the rubber, as commonly . As is known to those skilled in the art, depending on the intended use of the material vulcanized with sulfur and which can be vulcanized with 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 paraffinic process oils. Typical amounts of antioxidants comprise approximately 1 to 5 per. Representative antioxidants can be, for example, diphenyl-p-phenylenediamine and others such as, for example, those described in The Vanderbilt Rubber Handbook (1978), pages 344-346. Typical amounts of antiozonants comprise approximately from 1 to 5 per. Typical amounts of fatty acids, if used, which may include stearic acid, may comprise approximately 0.5 to 3 per. Typical amounts of zinc oxide comprise approximately 2 to 5 per. 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. 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 a synergistic effect on the final properties and are somewhat better than those produced by the use of any single accelerator. In addition, delayed action accelerators may be used that do not affect normal process temperatures, but produce a satisfactory cure at ordinary vulcanization temperatures. Vulcanization 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 achieved by methods known to those skilled in the rubber blending art. For example, the ingredients are typically mixed in at least two stages, that is, at least one non-productive stage, followed by a productive mixing step. The final curing agents are typically mixed in the final stage, which is conventionally referred to as the "productive" mixing stage where this mixture traditionally occurs at a temperature, or final temperature, lower than the mixing temperature, as compared to ( s) stage (s) of previous nonproductive mixture (s). The rubber and the polymeric resin 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 blending.

The vulcanization of the pneumatic tire of the present invention is generally carried out at conventional temperatures ranging from about 100 to 2002C. 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. The following examples are presented in order to illustrate, but not limit, the present invention. The healing properties were determined using a Monsanto oscillating disk rheometer, which was operated at a temperature of 150sc and at a frequency of 11 hertz. A description of the oscillator discs can be found in the Vanderbilt Rubber Handbook, edited by Robert 0. Ohm (Nor alk, Conn., RT Vanderbilt Company, Inc., 1990 =, pages 554-447. This curing meter and the standardized values read from the curve are specified in ASTM D-2084. A typical cure curve, obtained on an oscillating disc rheometer, is shown on page 555 of the 1990 edition of the manual Vanderbilt Rubber Handbook In such an oscillating disc rheometer, the composite rubber samples were subjected to a constant amplitude oscillating shearing action The torsion of the oscillating disc embedded in the material being tested, required to oscillate the rotor at the temperature was measured. of vulcanization The values obtained using this curing test are very significant, since the changes in the rubber or the composition formulation are very easily detected. badly advantageous to have a fast healing regime. In the following examples, the Flexsys Rubber Process Analyzer (RPA) 2000 analyzer was used to determine the dynamic mechanical rheological properties. The healing conditions were: 166SC, 1667 Hz, 15.8 minutes and effort of 0.7 percent. A description of the RPA 2000 analyzer, its capacity, sample preparation, tests and subtests, can be found in these references. H A Pawlowski and J S Dick, Rubber World, June 1992; J S. Dick and H A Pawlowski, Rubber World, January 1997 and J S Dick and J A Pawlowski, Rubber & Plastics News, April 26 and May 10 of a993. The composite rubber sample is placed on the bottom die. When the dies are brought together, the sample is in a pressurized cavity, where it will be subjected to a sinusoidal oscillating action of the bottom die. A torsion transducer, connected to the upper die, measures the amount of torsion transmitted through the sample, as a result of the oscillations. The torsion is transferred in the cutting module, G, by correcting the shape factor of the die and the stress. The RPA 2000 analyzer is capable of testing rubber without curing or curing with a high degree of repetition and reproduction. The tests and subtests available include constant and constant temperature frequency sweeps, constant temperature and frequency curing, constant stress and temperature sweep at constant frequency and frequency sweep. The accuracy and precision of the instrument allows the detection of reproducible changes in the composite sample. The values reported for the storage module, (G1), loss of elasticity (J ") and delta tangent are obtained from an effort sweep at 1002C and 1Hz, followed by the curing test.These properties represent the viscoelastic response of a Test sample to cut deformation at a constant temperature and frequency.

EXAMPLE 1 In a reactor were placed 10 parts of heptane and 2 parts of anhydrous aluminum chloride. While continuously stirring the mixture, 200 parts of a hydrocarbon mixture was added slowly to the reactor in a period of about 60 minutes. The hydrocarbon mixture consists of 50 percent inert hydrocarbons, with the remaining 50 percent by weight of the mixture comprising the following components that make up the resin: The temperature of the reaction was maintained in a range of approximately 25 to 30 ° C. After one hour of agitation from the time of final addition, the hydrocarbon mixture was added to about 50 parts of a 25 percent solution of isopropyl alcohol in water, to neutralize and decompose the aluminum chloride. The aqueous layer was removed and the resin solution was washed with an additional 50 parts of the alcohol / water mixture. The resulting resin solution was steam distilled at a pot temperature of approximately 235SC. The resulting residual molten resin is emptied from the pot on an aluminum tray and cooled to room temperature to form 98 parts of a hard, pale, brittle yellow resin having a softening point (Ball and Ring) according to the Method of ASTM F28-58T from 120 to 128SC, after several repeated preparations. The small molecule GPC analysis gives a molecular weight distribution of 5.4 percent in the range of 10.450, 94.4 percent in the range of 3050 and 0.2 percent in the range of 430. EXAMPLE 2 In this example, several resins were evaluated in a rubber compound. Rubber compositions containing the materials set forth in Tables 1 and 2 were prepared in a Banbury ™ BR mixer, using two separate stages of addition (mixing); that is, a non-productive mixing stage and a productive mixing stage. The non-productive stage was mixed for 3.5 minutes or at a rubber temperature of 1602C, whichever comes first. The mixing time for the productive stage was at a rubber temperature of 1202C. The rubber compositions were identified here as Samples 1-3. Samples 1 and 2 are considered here as controls, without the use of the resin used in the present invention added to the rubber composition. Samples 1 and 2 each contain commercially available resins. The samples were cured at about 150 ° C for about 28 minutes. Table 2 illustrates the behavior and physical properties of the cured samples 1-3. Sample 3 was mixed and tested twice with each data set being presented in table 2.

The modulus values (G1 § 40%) for Sample 3 indicate improved durability compared to Sample 1. The tan delta and J "values for Sample 3 indicate equal dry tractions compared to Sample 1. Although the values of the modulus (G1 @ 40%) for Sample 2 are greater than for Sample 3, these tan delta and J "values suggest that Sample 3 is significantly superior in dry traction. 1 The SBR solution contains 34% styrene, a Tg of -172C and a basic Mooney viscosity of 88, when the oil is diluted (25 per oil) the Mooney viscosity was 45. The SBR solution was obtained from The Goodyear Tire & Rubber Company. 2 I2 = 122 and DBP = 114 3 The non-reactive phenol resin and formaldehyde have a melting point of 106-1142C (Ring and Ball) which is commercially available from Schenectady Chemical under the designation CRJ-418 4 The resin of Cumarona-Indeno has a softening point of 1002C, and is commercially available from Neville Chemical under the designation Cumar ™ R-13. 5 Benzothiazole-2-sulfenamide of N-cyclohexyl 6 Disulfide of tetramethylthiouram Table 2 While certain representative embodiments and details have been shown in order to illustrate the invention, it will be apparent to those skilled in the art that various changes and modifications can be made therein, without departing from the spirit or scope of the invention.

Claims (10)

1. A pneumatic tire, having a tread, characterized by (a) an elastomer based on a diene, containing olefinic unsaturations and (b) from 1 to 50 parts per hundred resin (per) of a polymeric resinous material, which comprises from 4 to 60 weight percent of units derived from piperylene, from about 10 to 35 weight percent of units derived from 2-methyl-2-butene and from 18 to 50 weight percent of units derived from the dicyclopentadiene.

2. A pneumatic tire, according to claim 1, characterized in that the polymer resinous material has a softening point of about 100 to 160 C.

3. A pneumatic tire, according to claim 1, characterized in that the polymer resinous material is modified to contain up to about 25 weight percent of units derived from piperylene dimers, piperylene trimers and other unsaturated hydrocarbons, containing from 4 to 6 carbon atoms.

4. A pneumatic tire, according to claim 3, characterized in that the other unsaturated hydrocarbons, containing from 4 to 6 carbon atoms, are selected from 2-methyl-1-butene, 2,3-dimethyl-1-butene, 2 , 3-dimethyl-2-butene, 3,3-dimethyl-l-butene, 1-pentene, 2-pentene, 2-methyl-l-pentene, 2-methyl-2-pentene, 3-raetyl-2-pentene , 4-methyl-1-pentene, 4-methyl-2-pentene, 2-hexene, 1,3-butadiene, isoprene, cyclopentene, cyclohexene and 1,3-cyclopentadiene.

5. A pneumatic tire, according to claim 1, characterized in that the polymeric resinous material is prepared by the method which comprises polymerizing a mixture comprising about 4 to 60 weight percent piperylene, from about 10 to 35 weight percent. weight of 2-methyl-2-butene and about 18 to 50 weight percent of dicyclopentadiene, in the presence of an anhydrous halide catalyst, selected from the fluorides, chlorides and bromides of aluminum, tin and boron, and dihalides of alkyl aluminum, selected from methyl aluminum dichloride, ethyl aluminum dichloride and isopropyl aluminum dichloride.

6. A pneumatic tire, according to claim 5, characterized in that the halide catalysts are selected from aluminum chloride, stannic chloride, boron trifluoride, methyl aluminum dichloride, ethyl aluminum dichloride and isopropyl aluminum dichloride.

7. A pneumatic tire, according to claim 1, characterized in that the elastomer, which contains the olefinic unsaturation, is selected from the group consisting of natural rubber, neoprene, polyisoprene, polybutadiene, styrene-butadiene copolymer, styrene rubber / isoprene / butadiene, copolymer of methyl methacrylate and butadiene, copolymer of isoprene and styrene, copolymer of methyl methacrylate and isoprene, copolymer of acrylonitrile and isoprene, copolymer of acrylonitrile and butadiene, EPDM and their mixtures.

8. A pneumatic tire, according to claim 1, characterized in that the elastomer is a copolymer of styrene and butadiene.

9. A pneumatic tire, according to claim 8, characterized in that the styrene-butadiene copolymer has a content of the linking styrene of 20 to 45 percent.

10. A pneumatic tire, according to claim 1, characterized in that a filling is present in the elastomer, in an amount ranging from 10 to 250 parts per hundred resin.