Rubber composition and article of manufacture comprising rubber composition

Abstract

To provide a rubber composition for tire components which maintains stiffness properties beyond 120°C.SOLUTION: A rubber composition comprises at least one rubber, at least one filler, at least one thermoplastic polymer, where the thermoplastic polymer is a poly(alkylacrylate), and where the alkylacrylate comprises a polycyclic substituent at its single bonded oxygen atom.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention is directed to rubber compositions, particularly rubber compositions for tires. Further, the present invention is directed to manufactured articles selected from tires, power transmission belts, hoses, caterpillars, air sleeves and conveyor belts, including such rubber compositions or components comprising a rubber composition.

Background Art

[0002] Rubber compositions, particularly rubber compositions for tires (although not limited to such uses), must meet multiple requirements such as durability, rigidity, elasticity, low hysteresis and more. To further improve the properties of rubber compositions for some applications, the use of ultra-high molecular weight polyethylene (UHMWPE) has been suggested in the past. However, the use of polyethylene materials is useful for improving rubber properties such as rigidity in some applications, but there are also some disadvantages. For example, one problem is the relatively low melting point of about 135 °C of the rubber composition. Another disadvantage of polyethylene is that processing and dispersion in rubber formulations are difficult, and thus the desired reinforcing effect is restricted due to relatively poor dispersion. Furthermore, rigidity can also be improved by preparing appropriate filler materials. However, increasing such fillers in large amounts may also cause several disadvantages such as weight increase and other problems during mixing. There are many methods for imparting high rigidity to rubber compositions, but there is still considerable room for improvement.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0004] [Non-Patent Document 1] Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition [Non-Patent Document 2] Journal of the American Chemical Society, Vol. 60, p. 304 (1930) [Non-Patent Document 3] The Vanderbilt Rubber Handbook (1978), pp. 344-346 [Overview of the project] [Means for solving the problem]

[0005] A first object of the present invention may be to provide an advanced rubber composition, particularly for tire components. Another object of the present invention may be to provide an advanced high-rigidity rubber composition that maintains rigidity properties substantially above 120°C.

[0006] Another object of the present invention may be to provide an advanced, high-rigidity rubber composition, particularly one with a limited weight. The present invention is defined by the independent claims. Further preferred embodiments are given in the dependent claims, abstract and the following description herein.

[0007] In one embodiment of the present invention, a rubber composition is provided, particularly for tires or tire (rubber) components, the rubber composition comprising at least one elastomer, at least one filler, and at least one thermoplastic polymer, the thermoplastic polymer being an alkyl polyacrylate, wherein the alkyl polyacrylate contains a polycyclic substituent on its single bonded oxygen atom. The presence of such an alkyl polyacrylate reinforces the rubber compound by significantly restricting the mobility of the chains within the material.

[0008] In this embodiment, the alkyl polyacrylate has the following structure:

[0009] [Formula 1]

[0010] [In the formula, n is the number of alkyl acrylate monomers in the alkyl polyacrylate, R1 is an alkyl such as CH3 (methyl) or C2H5 (ethyl), and R2 is a polycyclic hydrocarbon substance / group, or in other words, a hydrocarbon substituent at the OH (hydroxyl) group of the (alkyl) acrylate / acrylic group.] Such materials have been found to be even more desirable, for example, due to the bulky substituent R2 which can further improve the rigidity of the compound. Furthermore, the alkyl polyacrylate with its bulky side chain group / substituent helps to improve processability (and also due to its amorphous nature) and also has relatively high heat resistance. In particular, the force that causes phase separation during mixing is not very strong, which can also help to achieve better dispersion.

[0011] In general, the suggested alkyl polyacrylates can provide better reinforcement for rubber matrices with limited hysteresis. Furthermore, the suggested alkyl acrylates are relatively lightweight materials compared to silica or carbon black, given the achievement of comparable reinforcement. Such properties, or combinations thereof, cannot be easily achieved by simply adding more carbon black or silica to the rubber composition. Adding more of such substances can increase weight and / or hysteresis. Moreover, this can make mixing more difficult or alter other properties of the compound in undesirable ways.

[0012] In yet another embodiment, the alkyl acrylate has one of a bicyclic substituent and a tricyclic substituent. In yet another embodiment, the alkyl acrylate has a hydrocarbon substituent containing at least 8 carbon atoms, with at least 7 carbon atoms and optionally at least 5 carbon atoms (optionally at least 6 carbon atoms) arranged cyclically. These have been found to be desirable materials.

[0013] In another embodiment, the alkyl polyacrylate is one of poly(isobornyl methacrylate) (also referred to herein as PIBOMA) and poly(adamantyl methacrylate) (also referred to herein as PADAM). These materials were identified by the inventors as two materials that possess properties most desirable, particularly in terms of reinforcement. Furthermore, bulky side chain groups or substituents help to enhance processability and provide a relatively high glass transition temperature, which can serve as an indicator of the heat resistance of the material in the vulcanized compound.

[0014] In yet another embodiment, the alkyl polyacrylate has one or more of the following structures (wherein n is preferably an integer equal to and / or greater than 1):

[0015] [Case 2]

[0016] Generally, the polymer itself is commercially available and / or can be prepared, for example, by radical polymerization, ionic polymerization, coordination polymerization, reversible addition-fragmentation chain transfer (RAFT) polymerization or atom transfer radical (ATRP) polymerization.

[0017] In yet another embodiment, the molecular weight Mn of the thermoplastic polymer is at least 20,000 g / mol, optionally at least 30,000 g / mol. At such minimum molecular weights, a greater effect of reinforcement is observed, and it has been found that it may be desirable to avoid too low softening points and / or melting points. Mn and / or Mw can be appropriately determined by GPC in accordance with ASTM standard D5296, especially using polystyrene calibration standards.

[0018] In yet another embodiment, the molecular weight Mn of the thermoplastic polymer is less than 2,000,000 g / mol, or preferably less than 1,000,000 g / mol. In yet another embodiment, the polydispersity index Mw / Mn of the polyacrylic acid alkyl is at least 1.1, preferably at least 1.5, optionally exceeding 1.8 but preferably less than five.

[0019] In yet another embodiment, the glass transition temperature Tg of the polyacrylic acid alkyl is at least 140 °C, preferably at least 150 °C, optionally between 170 °C and 250 °C. Tg can be appropriately determined as the median of the peak by a differential scanning calorimeter (DSC) at a heating rate of 10 °C per minute in accordance with ASTM D3418 or the equivalent.

[0020] In yet another embodiment, the rubber composition comprises 100 phr of one or more diene / diene-based rubbers, 20 to 190 phr (preferably 120 phr) of a filler, and 5 to 50 phr of a polyacrylic acid alkyl. Such filler contents and polyacrylic acid alkyl contents have been found to be most desirable.

[0021] In another embodiment, the filler is one of carbon black, silica, and pre-silanized silica. In yet another embodiment, the elastomer (or rubber), or diene / diene rubber, is one or more of styrene-butadiene rubber, polybutadiene (rubber), solution-polymerized styrene-butadiene rubber, emulsion-polymerized styrene-butadiene rubber, natural rubber, and synthetic polyisoprene (rubber).

[0022] In yet another embodiment, the rubber composition comprises 10 phr to 40 phr of alkyl polyacrylate, and optionally 15 phr to 35 phr of alkyl polyacrylate. These ranges were found to be most desirable by the inventors.

[0023] The rubber composition may contain at least one or at least one additional diene rubber. Typical synthetic polymers include butadiene and its congeners and derivatives, such as homopolymer products of methylbutadiene, dimethylbutadiene, and pentadiene, and copolymers formed from butadiene or its congeners or derivatives with other unsaturated monomers. Other unsaturated monomers include acetylene, such as vinylacetylene; olefins, such as isoprene, which copolymerizes with isoprene to form butyl rubber; vinyl compounds, such as acrylic acid, acrylonitrile (which polymerizes with butadiene to form NBR), methacrylic acid, and styrene (styrene polymerizes with butadiene to form SBR); and vinyl esters and various unsaturated aldehydes, ketones, and ethers, such as acrolein, methylisopropenyl ketone, and vinyl ethyl ether. Specific examples of synthetic rubbers include neoprene (polychloroprene), polybutadiene (including cis-1,4-polybutadiene), polyisoprene (including cis-1,4-polyisoprene), halobutyl rubber such as butyl rubber, chlorobutyl rubber, or bromobutyl rubber, copolymers of 1,3-butadiene or isoprene with monomers such as styrene / isoprene / butadiene rubber, styrene, and acrylonitrile, as well as ethylene / propylene terrapolymers, also known as ethylene / propylene / diene monomer (EPDM), particularly ethylene / propylene / dicyclopentadiene terrapolymers. Additional examples of rubbers that may be used include alkoxysilyl-terminated solution polymers (SBR, PBR, IBR, and SIBR), star-branched polymers coupled with silicon and tin. Preferred rubbers or elastomers are natural rubber, synthetic polyisoprene, polybutadiene, and SBR.

[0024] In one embodiment, the rubber is preferably at least two diene rubbers. For example, a combination of two or more rubbers is preferred, such as cis-1,4-polyisoprene rubber (natural or synthetic, but natural is preferred), 3,4-polyisoprene rubber, styrene / isoprene / butadiene rubber, styrene / butadiene rubber derived from emulsion and solution polymerization, cis-1,4-polybutadiene rubber, and butadiene / acrylonitrile copolymer prepared by emulsion polymerization.

[0025] In one embodiment of the present invention, emulsion polymerization-derived styrene / butadiene (ESBR) having a relatively old-fashioned styrene content of 20 to 28 percent bound styrene may be used, or in some applications, ESBR having a moderate to relatively high bound styrene content, i.e., 30 to 45 percent bound styrene, may be used. Emulsion polymerization-prepared ESBR means that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion. Such things are well known to those skilled in the art. The bound styrene content may vary, for example, from 5 to 50 percent. In one embodiment, ESBR may also contain acrylonitrile in an amount of 2 to 30 weight percent bound acrylonitrile in the terpolymer, for example, to form a terpolymer rubber as ESBAR. Styrene / butadiene / acrylonitrile copolymer rubber prepared by emulsion polymerization containing 2 to 40 weight percent bound acrylonitrile in the copolymer is also intended as a diene-based rubber used in the present invention.

[0026] In another embodiment, SBR (SSBR) prepared by solution polymerization can be used. Such SSBR may have a bound styrene content in the range of, for example, 5 to 50, preferably 9 to 36 percent. SSBR can conveniently be prepared by anionic polymerization, for example, in an inert organic solvent. In particular, SSBR can be synthesized by copolymerization of styrene and 1,3-butadiene monomer in a hydrocarbon solvent using an organolithium compound as an initiator.

[0027] In one embodiment, cis-1,4-polybutadiene rubber (BR) may be used. Such BR can be prepared, for example, by organic solution polymerization of 1,3-butadiene. The BR can conveniently be characterized by having, for example, a cis-1,4-content of at least 90 percent. This content can also be applied to other cis-1,4 rubbers or synthetic polyisoprenes listed herein.

[0028] cis-1,4-polyisoprene and cis-1,4-polyisoprene natural rubber are well known to those skilled in rubber technology. In one embodiment, cis-1,4-polybutadiene rubber (BR) is used. A suitable butadiene rubber can be prepared, for example, by organic solution polymerization of 1,3-butadiene. BR can conveniently be characterized by having, for example, a cis-1,4- content of at least 90 percent and a glass transition temperature Tg in the range of -95 to -105°C. Suitable butadiene rubbers such as Budene® 1207, Budene® 1208, or Budene® 1223 are commercially available from The Goodyear Tire & Rubber Company. These high cis-1,4-polybutadiene rubbers can be synthesized, for example, using a nickel catalyst system comprising a mixture of (1) an organonicickel compound, (2) an organoaluminum compound, and (3) a fluorine-containing compound, as described in U.S. Patents 5,698,643 and 5,451,646, which are incorporated herein by reference.

[0029] In one embodiment, synthetic or natural isoprene rubber may be used. Where used herein, the term "phr" refers, in accordance with conventional convention, to "parts by weight of each material per 100 parts by weight of rubber or elastomer." Generally, using this convention, a rubber composition consists of 100 parts by weight of rubber / elastomer. A composition described in the claims may contain rubber / elastomers other than those expressly described in the claims, provided that the phr values ​​of the rubber / elastomers described in the claims match the phr range described in the claims and the total amount of rubber / elastomers in the composition amounts to 100 parts of rubber. For example, a composition may further contain 1 to 10 phr, optionally 1 to 5 phr, of one or more additional diene rubbers, such as SBR, SSBR, ESBR, PBD / BR, NR, and / or synthetic polyisoprene. In another example, a composition may contain less than 5 phr, preferably less than 3 phr, of additional diene rubbers, or may not contain any such additional diene rubbers at all. The terms “compound” and “composition” may be used interchangeably in this specification unless otherwise indicated.

[0030] The rubber composition may also contain process oil up to 70 phr. Typically, process oil may be included in the rubber composition as an extender used to increase the volume of the elastomer. Process oil may also be included in the rubber composition by direct addition of oil during rubber compounding. The process oil used may include both extenders present in the elastomer and process oils added during compounding. Suitable process oils include a variety of oils known in the industry, including aromatic, paraffin, naphthenic, vegetable oils, and low PCA oils such as MES, TDAE, SRAE, and heavy naphthenic oils. Suitable low PCA oils include those having a polycyclic aromatic content of less than 3 weight percent as determined by the IP346 method. The procedure for the IP346 method can be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, published by the Institute of Petroleum, United Kingdom.

[0031] The rubber composition may preferably contain 50 to 150 phr of silica. In another embodiment, silica may be used in amounts of 60 to 190 phr (preferably 120 phr). Commonly used siliceous pigments that may be used in rubber compounds include conventional igneous and precipitated siliceous pigments (silica). In one embodiment, precipitated silica is used. Conventional siliceous pigments used in the present invention are precipitated silica, such as soluble silicates, such as those obtained by acidification of sodium silicate.

[0032] Such conventional silica may be characterized by having a BET surface area, which can be measured using, for example, nitrogen gas. In one embodiment, the BET surface area may be in the range of 40 to 600 square meters per gram. In another embodiment, the BET surface area may be in the range of 80 to 300 square meters per gram. The BET method for measuring surface area is described in the Journal of the American Chemical Society, Vol. 60, p. 304 (1930).

[0033] Furthermore, conventional silica may be characterized by having a dibutyl phthalate (DBP) absorption value in the range of 100 to 400, or alternatively, 150 to 300. Conventional silica can be expected to have an average ultimate particle size in the range of 0.01 to 0.05 microns, as determined, for example, by an electron microscope, but silica particles may be even smaller in size, or possibly larger.

[0034] Various commercially available silicas may be used, such as, but are not limited to, those commercially available from PPG Industries under the Hi-Sil trademark, with names such as 210, 315G, and EZ160G; silicas available from Solvay, with names such as Z1165MP and Premium200MP; and silicas available from Evonik AG, with names such as VN2 and Ultrasil 6000GR, 9100GR.

[0035] Commonly used carbon black can be used as a conventional filler in amounts ranging from 10 to 150 phr. In another embodiment, 20 to 80 phr of carbon black may be used. Typical examples of such carbon blacks include N110, N121, N134, N220, N231, N234, N242, N293, N299, N315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990, and N991. These carbon blacks have iodine absorption ranging from 9 to 145 g / kg and 34 to 150 cm³. 3 It has DBP counts in the range of / 100g.

[0036] Other fillers that may be used in the rubber composition include, but are not limited to, granular fillers containing ultra-high molecular weight polyethylene (UHMWPE), crosslinked granular polymer gels including, but not limited to, those disclosed in U.S. Patent Nos. 6,242,534; 6,207,757; 6,133,364; 6,372,857; 5,395,891 and 6,127,488, and plasticized starch composite fillers including, but not limited to, those disclosed in U.S. Patent No. 5,672,639. Other such fillers may be used in amounts ranging from 1 to 30 phr.

[0037] In one embodiment, the rubber composition may contain a conventional sulfur-containing organosilicon compound. An example of a suitable sulfur-containing organosilicon compound is given by formula: Z-Alk-S n -Alk-Z (I) [In the formula, Z is,

[0038] [C3]

[0039] (In the formula, R 1R is an alkyl group, cyclohexyl, or phenyl having 1 to 4 carbon atoms, 2 (These are alkoxys having 1 to 8 carbon atoms, or cycloalkoxys having 5 to 8 carbon atoms.) Selected from the group consisting of [the specified group], where Alk is a divalent hydrocarbon having 1 to 18 carbon atoms, and n is an integer from 2 to 8. It holds.

[0040] In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(trimethoxy or triethoxysilylpropyl) polysulfide. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(triethoxysilylpropyl) disulfide and / or 3,3'-bis(triethoxysilylpropyl) tetrasulfide. Therefore, for formula I, Z is

[0041] [C4]

[0042] [In the formula, R 2 It is an alkoxy having 2 to 4 carbon atoms, or alternatively, 2 carbon atoms. Alk is a divalent hydrocarbon having 2 to 4 carbon atoms, or 3 carbon atoms as an alternative, and n is an integer from 2 to 5, or 2 or 4 as an alternative.

[0043] In another embodiment, suitable sulfur-containing organosilicon compounds include compounds disclosed in U.S. Patent No. 6,608,125. In one embodiment, the sulfur-containing organosilicon compound includes 3-(octanoylthio)-1-propyltriethoxysilane, CH3(CH2)6C(=O)-S-CH2CH2CH2Si(OCH2CH3)3, which is commercially available from Momentive Performance Materials as NXT®.

[0044] In another embodiment, suitable sulfur-containing organosilicon compounds include those disclosed in U.S. Patent Application Publication No. 2003 / 0130535. In one embodiment, the sulfur-containing organosilicon compound is Si-363 from Degussa.

[0045] The amount of sulfur-containing organosilicon compound in the rubber composition may vary depending on the levels of other additives used. Generally speaking, the amount of the compound is in the range of 0.5 to 20 phr. In one embodiment, the amount is in the range of 1 to 10 phr.

[0046] It is readily apparent to those skilled in the art that rubber compositions (in other words, sulfur-vulcanizable rubber compositions) can be formulated by methods generally known in rubber compounding technology, such as mixing sulfur-vulcanizable constituent rubbers of various components with various commonly used additive materials, including sulfur donors, curing aids such as activators and retarders, as well as processing additives such as oils, resins including adhesive resins and plasticizers, fillers, pigments, fatty acids, zinc oxide, waxes, antioxidants, ozone degradation inhibitors and desorbents. As is known to those skilled in the art, the additives listed above are selected and generally used in conventional amounts depending on the intended use of the sulfur-vulcanizable material and the sulfur-vulcanized material (rubber). Typical examples of sulfur donors include elemental sulfur (free sulfur), amine disulfides, polymeric polysulfides, and sulfur-olefin adducts. In one embodiment, the sulfur-vulcanizing agent is elemental sulfur. The sulfur-vulcanizing agent may be used in amounts ranging from 0.5 to 8 phr, or alternatively, in amounts ranging from 1.5 to 6 phr. The typical amount of tackifying resin, when used, is 0.5 to 10 phr, usually 1 to 5 phr. The typical amount of processing aid is 1 to 50 phr. The typical amount of antioxidant is 1 to 5 phr. Typical antioxidants may include, for example, diphenyl-p-phenylenediamine, or those disclosed, for example, in The Vanderbilt Rubber Handbook (1978), pages 344 to 346. The typical amount of ozone degradation inhibitor is 1 to 5 phr. The typical amount of fatty acid that can contain stearic acid, when used, is 0.5 to 3 phr. The typical amount of wax is 1 to 5 phr. Microcrystalline wax is often used. The typical amount of reconstituter is 0.1 to 1 phr. Typical reconstituters may include, for example, pentachlorothiophenol and dibenzamide diphenyl disulfide.

[0047] Accelerators can be used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanized product. In one embodiment, a single accelerator system, i.e., a primary accelerator, may be used. Primary accelerators may be used in a total amount ranging from 0.5 to 10 or 0.5 to 4, or alternatively, 0.8 to 1.5 phr. In another embodiment, a combination of primary and secondary accelerators may be used, with the secondary accelerator being used in smaller amounts, such as 0.05 to 3 phr, to activate and improve the properties of the vulcanized product. These accelerator combinations can be expected to produce a synergistic effect on the final properties, which may be somewhat better than those produced by the use of either accelerator alone. Furthermore, slow-acting accelerators may be used that are not affected by normal processing temperatures but produce satisfactory curing at normal vulcanization temperatures. Vulcanization retarders may 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. In one embodiment, the primary accelerator is a sulfenamide. When a second accelerator is used, the secondary accelerator is, for example, a guanidine, a dithiocarbamate, or a thiuram compound. Suitable guanidines include diphenylguanidine, etc. Suitable thiuram compounds include tetramethylthiuram disulfide, tetraethylthiuram disulfide, and tetrabenzylthiuram disulfide.

[0048] The mixing of rubber compositions can be achieved by methods known to those skilled in the art of rubber mixing technology. For example, the raw materials are typically mixed in at least two stages, namely at least one non-productive stage followed by a productive mixing stage. The final curing agent, including a sulfur vulcanizing agent, is typically mixed in a final stage conventionally called the “productive” mixing stage, where mixing is typically carried out at a temperature or final temperature lower than the mixing temperature of the preceding non-productive mixing stage(s). The terms “non-productive” and “productive” mixing stages are well known to those skilled in the art of rubber mixing technology. The rubber composition may also be subjected to a thermodynamic mixing step. The thermodynamic mixing step generally involves mechanical work in a mixer or extruder for a period of time suitable to produce a rubber temperature between 140°C and 190°C. The preferred duration of the thermodynamic work varies as a function of operating conditions and the amount and properties of the components. For example, the thermodynamic work may be 1 to 20 minutes.

[0049] In another embodiment of the present invention, a manufactured product is provided which may preferably be selected from tires, power transmission belts, hoses, caterpillars, air sleeves, and conveyor belts. This manufactured product comprises a rubber composition according to one or more of the above embodiments or elements thereof. Thus, the manufactured product comprises a rubber composition comprising at least one elastomer, at least one filler, and at least one thermoplastic polymer, wherein the thermoplastic polymer is an alkyl polyacrylate, and the alkyl acrylate has a polycyclic substituent on its single bonded oxygen atom.

[0050] In embodiments, a tire comprises at least one component made of a rubber composition, the component being at least one of a carcass ply, belt ply, overlay ply, apex, sidewall, tread, chipper, flipper, inner liner, chafer, ply strip, shoulder, undertread, tread cap, and tread base. In principle, the composition may be used in multiple of the tire components.

[0051] In another embodiment, the component is selected from at least one of carcass plies, belt plies, apex, sidewall, chipper, flipper, chafer, and shoulder. In other words, the rubber composition may be specially intended for components requiring high rigidity. The tread or any part thereof is not intended in this embodiment.

[0052] The tires, especially pneumatic tires, may be racing tires, passenger car tires, aircraft tires, agricultural tires, leveling machine tires, off-road tires, truck tires, etc. In one embodiment, the tire is a passenger car tire or a truck tire. The tire may also be radial or bias-ply.

[0053] The vulcanization of rubber compositions or (pneumatic) tires can generally be carried out at conventional temperatures in the range of 100°C to 200°C. In one embodiment, vulcanization is carried out at temperatures in the range of 110°C to 180°C. Any of the conventional vulcanization methods may be used, such as heating in a press or mold, or heating using superheated steam or hot air. Such tires can be assembled, molded, shaped and cured by a variety of known methods that are readily apparent to those skilled in the art.

[0054] The advantages of articles comprising a rubber composition according to one aspect of the present invention or one embodiment thereof or a combination thereof have already been described above. It should be emphasized that one or more embodiments or features thereof can be combined with each other within the scope of the present invention.

[0055] The structure, operation, and advantages of the present invention will become more apparent upon careful consideration of the following description, which is provided in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0056] [Figure 1] This is a schematic cross-sectional view of an example tire. [Modes for carrying out the invention]

[0057] Figure 1 is a schematic cross-sectional view of a tire 1. The tire 1 has a tread 10, an inner liner 13, a belt structure including four belt plies 11, a carcass ply 9, two sidewalls 2, and two bead regions 3 including a bead filler apex 5 and a bead 4. The exemplary tire 1 is suitable for mounting on the rim of a vehicle, e.g., a truck or a passenger car. As shown in Figure 1, the belt plies 11 may be covered by overlay plies 12. The carcass ply 9 includes a pair of axially opposite ends 6, each of which is combined with one of the beads 4. Each axial end 6 of the carcass ply 9 can be folded back around each bead 4 to a position that anchors each axial end 6. One or more of the carcass plies 9, belt plies 11 and overlay plies 12 may have a plurality of essentially parallel reinforcing members made of a woven material such as polyester, rayon or a suitable organic polymer compound, or made of metal wiring, comprising a rubber composition according to the present invention. The folded portion 6 of the carcass ply 9 can engage with the axially outer surfaces of the two flippers 8 and the axially inner surfaces of the two chippers 7. As shown in Figure 1, the exemplary tread 10 has four circumferential grooves, each groove can essentially define a U-shaped hole in the tread 10. The main portion of the tread 10 may be formed from one or more tread compounds, which may be any suitable tread compound(s).

[0058] The embodiment in Figure 1 suggests multiple tire components, including, for example, an apex 5, a chipper 7, a flipper 8, and an overlay 12, but such components are not essential to the present invention. Also, the folded end of the carcass ply 9 is not required to the present invention, or it may pass through the opposing surface of the bead area 3 and terminate on the axially inward side of the bead 4 instead of the axially outward side of the bead 4. The number of tire grooves may also be more or less than, for example, four. It should be emphasized that the present invention focuses on the use of a thermoplastic polymer, which is alkyl polyacrylate, in the rubber composition. Therefore, the description in Figure 1 should be understood as illustrative only and not necessarily limiting the present invention.

[0059] In an example of the present invention, the rubber composition, such as that found in tire 1, comprises an elastomer, particularly SSBR, and a filler which may include carbon black, silica, or a combination thereof. According to the present invention, the rubber composition also comprises a thermoplastic polymer which is an alkyl polyacrylate having a polycyclic substituent on its single bonded oxygen atom.

[0060] Table 1 shows three control samples containing SSBR rubber, fillers, oil, stearic acid, antioxidants, wax, zinc oxide, sulfur, and curing accelerators. Control sample 1 contains no thermoplastic polymer and is primarily reinforced with carbon black filler. In contrast, control sample 2 (also not according to the present invention) contains an additional 20 phr of polyethylene (PE) used for reinforcement purposes. Control sample 3 contains silica and silica couplers instead of carbon black, but does not contain PE. The examples of the present invention also do not contain PE. Example 1 of the present invention contains poly(isobornyl methacrylate) (PIBOMA) with a molecular weight of 50 k instead of 20 phr of PE, and Example 2 of the present invention contains PIBOMA 277 k instead of 20 phr of PE. Example 3 of the present invention contains poly(adamantyl methacrylate) (PADAM) with a molecular weight of 38 k g / mol. Both PIBOMA and PADAM are useful for reinforcing rubber compounds. Example 4 of the present invention contains silica combined with PIBOMA 277 k.

[0061] [Table 1]

[0062] Table 2 shows the measured storage modulus (E') values ​​for the compositions already listed in Table 1, and the storage modulus can be considered an index of stiffness. In particular, Table 2 shows improved reinforcement, especially in the high-temperature range, for example, above 150°C. Samples containing only carbon black or silica (without thermoplastic reinforcement) have lower storage modulus values ​​than all other materials shown that contain thermoplastic material. Considering the temperature dependence of the storage modulus in compositions containing polyethylene, the reinforcement is relatively good up to the softening point of polyethylene, but then drops considerably around the melting point of about 135°C, which can be seen in the values ​​above 150°C in Table 2. The examples of the present invention of poly(isobornyl alkyl acrylate) and poly(adamantyl alkyl acrylate) do not show a rapid decline behavior. In particular, the storage modulus value drops by almost 40% for PE samples between 100°C and 150°C, but the drop for the examples of the present invention is less than about 10% within the same temperature range. Furthermore, at temperatures above 150°C, the storage modulus is higher for Examples 1, 2, 3, and 4 of the present invention than for Control 2 (i.e., the PE sample).

[0063] [Table 2]

[0064] Table 3 below shows the glass transition temperatures of the thermoplastic polymers used in the compositions examined in the context of Tables 1 and 2 (i.e., not the glass transition temperature of the entire rubber composition). The glass transition temperatures of the thermoplastic polymers used in the examples of the present invention are significantly higher than the softening point of UHMWPE, which is approximately 135°C, used in control sample 2.

[0065] [Table 3]

[0066] Modifications in the present invention are possible in light of the provided description. While certain representative embodiments, examples, and details have been given for the purpose of illustrating the subject invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing the scope of the invention. In any case, the above embodiments and examples should not be understood in an restrictive sense. In particular, the features of the above embodiments may also be interchangeable or combined with one another.

Claims

1. At least one elastomer, At least one filler, At least one thermoplastic polymer A rubber composition comprising: The thermoplastic polymer has the following structure: 【Chemistry 1】 [In the formula, n is the number of monomers in the thermoplastic polymer; R 1 is alkyl; R 2 is a polycyclic hydrocarbon material. A rubber composition comprising:

2. The R 1 is CH ３ and C ２ H ５ The rubber composition according to claim 1, characterized in that it is one of the following:

3. The rubber composition according to claim 1 or 2, characterized in that R2 is one of a bicyclic and a tricyclic substituent.

4. The rubber composition according to any one of claims 1 to 3, characterized in that R2 is a hydrocarbon substituent containing at least 7 carbon atoms, with at least 5 carbon atoms arranged in a cyclic configuration.

5. The thermoplastic polymer is one of poly(isobornyl methacrylate) and poly(adamantyl methacrylate), and / or the thermoplastic polymer has the following structure: 【Chemistry 2】 The rubber composition according to claim 1 , characterized in that it comprises one or more of the following:

6. 6. A rubber composition according to claim 1, characterized in that the thermoplastic polymer has a molecular weight Mn of at least 20,000 g / mol and / or a molecular weight Mn of less than 2,000,000 g / mol and / or a polydispersity index Mw / Mn of at least 1.

5.

7. 7. A rubber composition according to claim 1, characterized in that the glass transition temperature Tg of the thermoplastic polymer is at least 140°C and / or is in the range of 170°C to 250°C.

8. 8. The rubber composition according to claim 1, characterized in that the rubber composition comprises 100 phr of one or more diene-based rubbers, 20 to 190 phr of at least one filler, and 5 to 50 phr of the thermoplastic polymer.

9. 9. A rubber composition according to any one of claims 1 to 8, characterized in that the filler is one or more of carbon black, silica and pre-silanized silica, and / or the elastomer is one or more of styrene-butadiene rubber, polybutadiene, solution polymerized styrene-butadiene rubber, emulsion polymerized styrene-butadiene rubber, natural rubber and synthetic polyisoprene.

10. The rubber composition according to any one of claims 1 to 9, characterized in that the rubber composition comprises from 10 phr to 40 phr of the thermoplastic polymer.

11. The rubber composition of claim 10, wherein the rubber composition comprises from 15 phr to 35 phr of a thermoplastic polymer.

12. 12. An article of manufacture selected from a tire (1), a power transmission belt, a hose, a caterpillar, an air sleeve and a conveyor belt, characterized in that it comprises a rubber composition according to any one of claims 1 to 11.

13. 13. The article of manufacture of claim 12, wherein the article is a tire (1) including a component comprising the rubber composition, the component being selected from at least one of a carcass ply (9), a belt ply (11), an apex (5), a sidewall (2), a chipper (7), a flipper (8), a chafer, and a shoulder.

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