Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
  • C08L9/06—Copolymers with styrene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
  • B60C1/0016—Compositions of the tread
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L21/00—Compositions of unspecified rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L75/00—Compositions of polyureas or polyurethanes; Compositions of derivatives of such polymers
  • C08L75/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2380/00—Tyres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L93/00—Compositions of natural resins; Compositions of derivatives thereof

Definitions

• the present invention relates to rubber compositions intended in particular for the manufacture of tires or semi-finished products for tires; it relates more particularly to the rubber compositions that can be used in the treads of these tires.
• a tire tread must obey in a known manner to a large number of technical requirements, often antithetical, among which a low rolling resistance, a high wear resistance, as well as a high adhesion on dry road as wet .
• a first object of the invention relates to a tire comprising a rubber composition comprising at least:
• a diene elastomer as the first elastomer, a diene elastomer
• thermoplastic polyurethane block copolymer with polyurethane blocks and polydiene blocks a thermoplastic polyurethane block copolymer with polyurethane blocks and polydiene blocks
• a plasticizer system comprising: at a content A of between 5 and 60 phr, a hydrocarbon resin having a Tg greater than 20 ° C;
• a + B is greater than 30 phr.
• the tires of the invention are particularly intended to equip tourism-type motor vehicles, including 4x4 vehicles (four-wheel drive) and SUV vehicles ("Sport Utility Vehicles", two-wheeled vehicles (including motorcycles) as well as industrial vehicles chosen in particular from vans and "heavy goods vehicles” such as buses, road transport vehicles such as trucks.
• 4x4 vehicles four-wheel drive
• SUV vehicles SUV vehicles
• Industrial Vehicles two-wheeled vehicles (including motorcycles)
• industrial vehicles chosen in particular from vans and "heavy goods vehicles” such as buses, road transport vehicles such as trucks.
• pce (usually “phr” in English) means parts by weight per hundred parts of elastomer or rubber (of the total elastomers if several elastomers are present).
• any range of values designated by the expression "between a and b" represents the range of values from more than a to less than b (i.e. terminals a and b excluded) while any range of values designated by the term “from a to b” means the range from a to b (i.e., including the strict limits a and b).
• glass transition temperature "Tg” All values of glass transition temperature "Tg” are measured in a known manner by DSC (Differential Scanning Calorimetry) according to ASTM D3418 (1999).
• the tire of the invention therefore has the essential characteristic that its tread comprises a rubber composition comprising at least a first diene elastomer, a particularly high level of reinforcing inorganic filler, a specific plasticizer system and, as a second elastomer, a thermoplastic polyurethane block copolymer with polyurethane blocks and polydiene blocks, components which will be described in detail below.
• the tread of the tire according to the invention comprises a rubber composition whose first essential characteristic is to comprise, as first elastomer, a diene elastomer.
• first elastomer or "rubber”, the two terms being considered synonymous
• diene elastomer or "rubber”, the two terms being considered synonymous
• elastomer or "rubber”, the two terms being considered synonymous
• diene monomers monomers bearing two carbon-carbon double bonds, conjugated or otherwise.
• the diene elastomer is preferably chosen from the group of diene elastomers (non-thermoplastic) consisting of polybutadienes (BR), synthetic polyisoprenes (IR), natural rubber (R), butadiene copolymers and isoprene copolymers. and mixtures of these elastomers.
• Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR) and isoprene-copolymers.
• SBIR butadiene-styrene
• the copolymers may contain between 99% and 20% by weight of diene units and between 1% and 80% by weight of vinylaromatic units.
• the elastomers may have any microstructure which is a function of the polymerization conditions used, in particular the presence or absence of a modifying and / or randomizing agent and the amounts of modifying and / or randomizing agent used.
• the elastomers can be for example block, statistical, sequenced, microsequenced, and be prepared in dispersion or in solution; they may be coupled and / or starred or functionalized with a coupling agent and / or starring or functionalization.
• silanol or polysiloxane functional groups having a silanol end as described for example in FR 2 740 778, US Pat. No. 6,013,718 and WO 2008/141702
• alkoxysilane groups as described for example in FR 2,765,882 or US 5,977,238,
• carboxylic groups as described for example in WO 01/92402 or US 6,815,473, WO 2004/096865 or US 2006/0089445).
• elastomers such as SBR, BR, NR or IR of the epoxidized type.
• Polybutadienes and in particular those having a content (mol%) in units -1.2 of between 4% and 80%, or those having a content (mol%) of cis-1,4 of greater than 80%, are suitable.
• Tg glass transition temperature
• styrene content between 5% and 60% by weight and more particularly between 20% and 50%, a content (mol%) in -1,2 bonds of the butadiene part of between 4% and 75%, a content (mol%) in trans-bonds -1,4 between 10% and 80%, butadiene-isoprene copolymers and especially those having an isoprene content of between 5% and 90% by weight and a Tg of -40 ° C to -80 ° C, the isoprene-styrene copolymers and in particular those having a styrene content of between 5% and 50% by weight and a Tg of between -5 ° C and -50 ° C.
• butadiene-styrene-isoprene copolymers are especially suitable those having a styrene content of between 5% and 50% by weight and more particularly of between 10% and 40%, an isoprene content of between 15% and 60%.
• the diene elastomer is chosen from the group consisting of polybutadienes, butadiene copolymers and mixtures of these elastomers. More preferably, it is a styrene-butadiene copolymer (SBR).
• SBR styrene-butadiene copolymer
• the composition comprises from 50 to 100 phr of an SBR elastomer, whether it be an emulsion-prepared SBR ("ESBR") or a SBR prepared in solution (“SSBR ").
• SBR emulsion-prepared SBR
• SSBR SBR prepared in solution
• the diene elastomer is a blend SBR / NR (or SBR / IR), BR / NR (or BR / IR), or SBR / BR / NR (or SBR / BR / IR).
• SBR elastomer ESBR or SSBR
• the diene elastomer is an isoprene elastomer.
• isoprene elastomer is meant in known manner a homopolymer or copolymer of isoprene, in other words a diene elastomer chosen from the group consisting of natural rubber (R) which can be plasticized or peptized, synthetic polyisoprenes (IR), different isoprene copolymers and mixtures of these elastomers.
• isoprene copolymers examples include butyl rubber - IIR), isoprene-styrene (SIR), isoprene-butadiene (BIR) or isoprene-butadiene-styrene (SBIR).
• This isoprene elastomer is preferably natural rubber or synthetic cis-1,4 polyisoprene; of these synthetic polyisoprenes, polyisoprenes having a content (mol%) of cis-1,4 bonds greater than 90%, more preferably still greater than 98%, are preferably used.
• the rubber composition comprises a blend of one (or more) diene elastomers called "high Tg” having a Tg between -70 ° C and 0 ° C and d one (or more) diene elastomers known as "low Tg” between -110 ° C and -80 ° C, more preferably between -105 ° C and -90 ° C.
• the high Tg elastomer is preferably selected from the group consisting of S-SBR, E-SBR, natural rubber, synthetic polyisoprenes (having a (mol%) content of cis-1,4 linkages of preferably greater than 95%), BIRs, SIRs, SBIRs, and mixtures of these elastomers.
• the low Tg elastomer preferably comprises butadiene units at a level (mol%) of at least 70%; it consists preferably of a polybutadiene (BR) having a content (mol%) of cis-1,4 chains greater than 90%.
• the rubber composition comprises, for example, between 30 and 90 phr, in particular between 40 and 90 phr, of a high Tg elastomer in a blend with a low Tg elastomer.
• the diene elastomer of the composition according to the invention comprises a blend of a BR (as low elastomer Tg) having a rate (% molar) of cis-chains. 1.4 greater than 90%, with one or more S-SBR or E-SBR (as elastomer (s) high Tg).
• the compositions of the invention may contain a single diene elastomer or a mixture of several diene elastomers.
• Thermoplastic polyurethane block copolymer Another essential characteristic of the rubber composition according to the invention is that it comprises at least, as second elastomer (another diene elastomer different from the first), a thermoplastic polyurethane block copolymer with polyurethane blocks and polydiene blocks having preferably a content of polydiene blocks greater than 5% by weight.
• Thermoplastic polyurethane block copolymers (abbreviated TPU) are well known, they have an intermediate structure between a thermoplastic polymer and an elastomer. They consist of rigid thermoplastic polyurethane blocks connected by flexible polydiene elastomeric blocks, for example polybutadiene or polyisoprene. Their synthesis is well known and explained for example in WO 2007/025690, as well as their applications in the field of rubber, especially in tires.
• the polydiene blocks are preferably chosen from the group consisting of polybutadiene blocks, polyisoprene blocks, butadiene copolymer blocks, isoprene block copolymers and mixtures of these blocks.
• the polydiene blocks are polybutadiene blocks.
• the company Sartomer sells, for example, the product "Poly Bd 2035", a thermoplastic polyurethane block copolymer, which notably comprises polybutadiene blocks.
• the tread composition of the tire according to the invention comprises an inorganic reinforcing filler (such as silica) in a proportion of 70 to 150 phr, preferably 100 to 150 phr.
• an inorganic reinforcing filler such as silica
• Reinforcing inorganic filler means any inorganic or mineral filler, irrespective of its color and origin (natural or synthetic), also called “white” filler, “clear” filler or even “non-black filler” as opposed to carbon black, capable of reinforcing on its own, without any other means than an intermediate coupling agent, a rubber composition intended for the manufacture of pneumatic tires, in other words able to replace, in its function reinforcement, a conventional carbon black of pneumatic grade; such a filler is generally characterized, in known manner, by the presence of hydroxyl groups (-OH) on its surface.
• -OH hydroxyl groups
• Suitable reinforcing inorganic fillers are in particular mineral fillers of the siliceous type, preferentially silica (SiO 2 ).
• the silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or fumed silica having a BET surface and a CTAB specific surface both less than 450 m 2 / g, preferably from 30 to 400 m 2 / g, especially between 60 and 300 m 2 / g.
• HDS highly dispersible precipitated silicas
• Hi-Sil silica EZ150G from PPG, the “Zeopol” silicas 8715, 8745 and 8755 from Huber, the high surface silicas specific as described in WO 03/16387.
• reinforcing inorganic filler mention may also be made of mineral fillers of the aluminous type, in particular alumina (Al 2 O 3) or aluminum (oxide) hydroxides, or reinforcing titanium oxides.
• the reinforcing inorganic filler comprises from 50 to 100% by weight of silica; in other words, the silica represents 50 to 100% by weight of the reinforcing inorganic filler.
• a reinforcing filler of another nature in particular an organic filler such as carbon black, since this filler reinforcing would be covered with an inorganic layer such as silica, or would comprise on its surface functional sites, including hydroxyl, requiring the use of a coupling agent to establish the connection between the filler and the elastomer.
• the level of reinforcing inorganic filler is preferably greater than 70 phr and less than 150 phr, more preferably between 100 and 150 phr.
• the composition of the tread may comprise carbon black.
• the carbon black when present, is preferably used at a level of less than 20 phr, more preferably less than 10 phr (for example between 0.5 and 20 phr, in particular between 2 and 10 phr). In the intervals indicated, it benefits from the coloring properties (black pigmentation agent) and anti-UV carbon blacks, without otherwise penalizing the performance provided by the reinforcing inorganic filler.
• a coupling agent (or bonding agent) is well known to provide a sufficient chemical and / or physical connection between the inorganic filler (surface of the its particles) and the diene elastomer.
• This coupling agent is at least bifunctional.
• organosilanes or at least bifunctional polyorganosiloxanes are used.
• polysulfide silanes called “symmetrical” or “asymmetrical” silanes according to their particular structure, are used, as described for example in the applications WO03 / 002648 (or US 2005/016651) and WO03 / 002649 (or US 2005/016650).
• polysulphide silanes having the following general formula (I) are not suitable for the following definition:
• x is an integer of 2 to 8 (preferably 2 to 5);
• the symbols A which are identical or different, represent a divalent hydrocarbon group (preferably an alkylene Ci-Cis or an arylene group C 6 -C 2, more particularly alkylene Ci-Cio, in particular C 1 -C 4 , especially propylene);
• the radicals R 1 which may be substituted or unsubstituted, which are identical to or different from one another, represent a C 1 -C 18 alkyl, C 5 -C 18 cycloalkyl or C 6 -C 18 aryl group (preferably C 1 -C 6 alkyl groups), cyclohexyl or phenyl, especially C 1 -C 4 alkyl groups, more particularly methyl and / or ethyl).
• the radicals R 2 substituted or unsubstituted, which are identical to or different from one another, represent a C 1 -C 18 alkoxyl or C 5 -C 18 cycloalkoxyl group (preferably a group chosen from C 1 -C 8 alkoxyls and C 5 cycloalkoxyls); 5 -C 8 , more preferably still a group selected from C 1 -C 4 alkoxyls, in particular methoxyl and ethoxyl).
• polysulphide silanes By way of examples of polysulphide silanes, mention may be made more particularly of bis (C 1 -C 4 ) alkoxy-C 1 -C 4 alkylsilyl-C 1 -C 4 alkyl (especially disulfide, trisulphide or tetrasulfide) polysulphides. )), such as polysulfides of bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl).
• TESPT bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• silanes carrying at least one thiol function (-SH) (called mercaptosilanes) and / or of at least one blocked thiol function, as described for example in patents or patent applications US 6,849,754, WO 99/09036, WO 2006/023815, WO 2007/098080, WO 2008/055986, WO 2010/072685.
• -SH thiol function
• the content of coupling agent is preferably between 2 and 20 phr, more preferably between 3 and 15 phr.
• Another essential feature of the tread composition of the tire according to the invention is to include a plasticizer system comprising:
• a + B is greater than 30 phr.
• the overall rate of plasticizing system A + B is greater than 40 phr, more preferably it is in a range of 50 to 100 phr, more preferably 50 to 80 phr.
• the liquid plasticizer is liquid at 20 ° C, it is said to "low Tg", that is to say that it has by definition a Tg less than -20 ° C, preferably less than -40 ° C.
• these plasticizers or these oils, more or less viscous are liquids (that is to say, as a reminder, substances having the capacity to eventually take on the shape of their container) , in contrast to, in particular, hydrocarbon plasticizing resins which are inherently solid at room temperature.
• Liquid plasticizers selected from the group consisting of liquid diene polymers, polyolefin oils, naphthenic oils, paraffinic oils, DAE (Distillate Aromatic Extracts) oils, MES (Medium Extracted Solvates) oils, TDAE oils are particularly suitable. ⁇ Treated Distillate Aromatic Extracts), Residual Aromatic Extracts (RAE) oils, Treated Residual Aromatic Extract (TREE) oils, Safety Residual Aromatic Extracts (SRAE) oils, mineral oils, vegetable oils, plasticizers, ethers, plasticizers esters, plasticizers, phosphates, sulphonate plasticizers and mixtures of these compounds.
• the liquid plasticizer is selected from the group consisting of MES oils, TDAE oils, naphthenic oils, vegetable oils and mixtures of these oils.
• the liquid plasticizer in particular petroleum oil, is of the non-aromatic type.
• a liquid plasticizer is described as non-aromatic if it has a content of polycyclic aromatic compounds, determined with the extract in DMSO according to the IP 346 method, of less than 3% by weight, relative to the total weight of the plasticizer.
• a liquid plasticizer chosen from the group consisting of MES oils, TDAE oils, naphthenic oils (at low or high viscosity, especially hydrogenated), paraffinic oils and mixtures of these oils.
• RAE oils, TRAE oils and SRAE oils or mixtures thereof which contain low levels of polycyclic compounds.
• the liquid plasticizer is a terpene derivative; as an example may be mentioned in particular the product "Dimarone" Yasuhara.
• Liquid polymers derived from the polymerization of olefins or dienes for example those chosen from the group consisting of polybutenes and polydienes, in particular polybutadienes, polyisoprenes, butadiene and isoprene copolymers, copolymers of butadiene or isoprene and styrene, and mixtures of these liquid polymers.
• the number-average molar mass of such liquid polymers is preferably in a range from 500 g / mol to 50,000 g / mol, more preferably from 1000 g / mol to 10,000 g / mol.
• the liquid plasticizer is a vegetable oil.
• a preferred use is an oil selected from the group consisting of linseed oil, safflower, soybean, corn, cotton, rape, castor oil, tungsten, pine, sunflower, palm, olive, coconut, peanut, grape seed, and mixtures of these oils, especially sunflower oil.
• This vegetable oil, particularly sunflower oil is more preferably an oil rich in oleic acid, that is to say that the fatty acid (or all the fatty acids, if several are present) from which it derives comprises oleic acid in a mass fraction of at least 60%, more preferably at least 70%, in particular equal to or greater than 80%.
• the liquid plasticizer is an ether; mention may be made, for example, of polyethylene glycols or polypropylene glycols.
• Liquid plasticizers chosen from the group consisting of ester plasticizers, phosphate plasticizers, sulphonate plasticizers and mixtures of these compounds are also suitable.
• Particularly suitable are the triesters selected from the group consisting of triesters of carboxylic acid, phosphoric acid, sulfonic acid and mixtures of these triesters.
• carboxylic acid ester plasticizers By way of examples of carboxylic acid ester plasticizers, mention may be made in particular of compounds selected from the group consisting of trimellitates, pyromellitates, phthalates, 1,2-cyclohexane dicarboxylates, adipates, azelates and sebacates. glycerol triesters and mixtures thereof.
• glycerol triesters preferably consisting mainly (for more than 50%, more preferably for more than 80% by weight) of a C 18 unsaturated fatty acid, ie in the group consisting of oleic acid, linoleic acid, linolenic acid and mixtures of these acids; more preferably, whether synthetic or natural, the fatty acid used is more than 60%, more preferably more than 70% by weight of oleic acid; such triesters (trioleates) with a high oleic acid content, of natural origin or of synthesis, are well known, they have been described for example in the application WO 02/088238, as plasticizing agents in bearing for tires.
• phosphate plasticizers mention may be made, for example, of those containing from 12 to 30 carbon atoms, for example trioctyl phosphate.
• the hydrocarbon resin has a Tg greater than 20 ° C.
• resin is herein reserved, by definition, to a compound that is solid at room temperature (20 ° C), as opposed to a liquid plasticizer such as an oil.
• Hydrocarbon resins are polymers well known to those skilled in the art, essentially based on carbon and hydrogen but may include other types of atoms, used in particular as plasticizers or tackifying agents in polymeric matrices. They are inherently miscible (ie, compatible) with the levels used with the polymer compositions for which they are intended, so as to act as true diluents. They have been described, for example, in the book "Hydrocarbon Resins" by R. Mildenberg, M. Zander and G.
• pneumatic rubber 5.5 "Rubber Tires and Mechanical Goods”
• They can be aliphatic, cycloaliphatic, aromatic, hydrogenated aromatic, aliphatic / aromatic type that is to say based on aliphatic and / or aromatic monomers.
• They may be natural or synthetic, whether or not based on petroleum (if so, also known as petroleum resins).
• Their Tg is preferably greater than 30 ° C, especially between 30 ° C and 95 ° C.
• these hydrocarbon resins can also be described as thermoplastic resins in that they soften by heating and can thus be molded. They can also be defined by a point or softening point (in English, "softening point”).
• the softening temperature of a hydrocarbon resin is generally about 50 to 60 ° C. higher than its Tg value.
• the softening point is measured according to ISO 4625 ("Ring and Bail” method).
• the macrostructure (Mw, Mn and Ip) is determined by size exclusion chromatography (SEC) as indicated below.
• the SEC analysis for example, consists in separating the macromolecules in solution according to their size through columns filled with a porous gel; the molecules are separated according to their hydrodynamic volume, the larger ones being eluted first.
• the sample to be analyzed is simply solubilized beforehand in a suitable solvent, tetrahydrofuran at a concentration of 1 g / liter. Then the solution is filtered on a 0.45 ⁇ porosity filter, before injection into the apparatus.
• the apparatus used is for example a "Waters alliance" chromatographic chain according to the following conditions: elution solvent: tetrahydrofuran; temperature 35 ° C; concentration 1 g / liter; flow rate: 1 ml / min; injected volume: 100 ⁇ ; Moore calibration with polystyrene standards; set of 3 columns “Waters” in series (“Styragel HR4E", “Styragel HR1” and “Styragel HR 0.5”); detection by differential refractometer (for example "WATERS 2410") that can be equipped with operating software (for example "Waters Millenium”).
• elution solvent tetrahydrofuran
• concentration 1 g / liter
• flow rate 1 ml / min
• injected volume 100 ⁇
• Moore calibration with polystyrene standards set of 3 columns “Waters” in series (“Styragel HR4E”, “Styragel HR1" and “Styragel HR
• the hydrocarbon resin has at least one, more preferably all of the following characteristics: a Tg greater than 20 ° C (in particular between 30 ° C and 100 ° C), more preferably greater than 30 ° C (especially between 30 ° C and 95 ° C); a softening point greater than 50 ° C (in particular between 50 ° C and 150 ° C);
• Mn a number-average molar mass (Mn) of between 400 and 2000 g / mol, preferably between 500 and 1500 g / mol;
• Ip Mw / Mn with Mw weight average molar mass
• hydrocarbon resins examples include those selected from the group consisting of cyclopentadiene homopolymer or copolymer resins (abbreviated to CPD), dicyclopentadiene homopolymer or copolymer resins (abbreviated to DCPD), terpene homopolymer or copolymer resins, C5 homopolymer or copolymer resins, C9 homopolymer or copolymer resins, alpha-methyl-styrene homopolymer or copolymer resins, and these resins.
• CPD cyclopentadiene homopolymer or copolymer resins
• DCPD dicyclopentadiene homopolymer or copolymer resins
• terpene homopolymer or copolymer resins C5 homopolymer or copolymer resins
• C9 homopolymer or copolymer resins alpha-methyl-styrene homopolymer or copolymer resins
• copolymer resins mention may be made more particularly of those selected from the group consisting of (D) CPD / vinylaromatic copolymer resins, (D) CPD / terpene copolymer resins, terpene phenol copolymer resins, (D) CPD / C5 cut copolymer resins, (D) CPD / C9 cut copolymer resins, terpene / vinylaromatic copolymer resins, terpene / phenol copolymer resins, C5 / vinylaromatic cut copolymer resins, and mixtures of these resins.
• pene here combines in a known manner the alpha-pinene, beta-pinene and limonene monomers; preferably, a limonene monomer is used which is present in a known manner in the form of three possible isomers: L-limonene (laevorotatory enantiomer), D-limonene (dextrorotatory enantiomer), or the dipentene, racemic of the dextrorotatory and levorotatory enantiomers. .
• Suitable vinylaromatic monomers are, for example, styrene, alpha-methyl styrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, vinyltoluene, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, the hydroxystyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene, any vinyl aromatic monomer from a C 9 fraction (or more generally from a C 8 -C 10).
• the resins selected from the group consisting of homopolymer resins (D) CPD, copolymer resins (D) CPD / styrene, polylimonene resins, limonene / styrene copolymer resins, resins of limonene / D copolymer (CPD), C5 / styrene cut copolymer resins, C5 / C9 cut copolymer resins, and mixtures of these resins.
• D homopolymer resins
• D copolymer resins
• D copolymer resins
• polylimonene resins limonene / styrene copolymer resins
• resins of limonene / D copolymer (CPD) resins of limonene / D copolymer
• C5 / styrene cut copolymer resins C5 / C9 cut copolymer resins
• the tread rubber compositions of the tires according to the invention also comprise all or part of the usual additives normally used in elastomer compositions intended for the production of treads, such as, for example, pigments, protective agents such as anti-ozone waxes, chemical antiozonants, anti-oxidants, anti-fatigue agents, reinforcing resins, acceptors (for example phenolic novolak resin) or methylene donors (for example HMT or H3M), a system crosslinking agents based on either sulfur, or sulfur and / or peroxide donors and / or bismaleimides, vulcanization accelerators, vulcanization activators.
• additives normally used in elastomer compositions intended for the production of treads such as, for example, pigments, protective agents such as anti-ozone waxes, chemical antiozonants, anti-oxidants, anti-fatigue agents, reinforcing resins, acceptors (for example phenolic novolak resin) or methylene donors (for example HMT or H3M
• compositions may also contain, in addition to the coupling agents, coupling activators, inorganic charge-covering agents or, more generally, processing aids that can be used in a known manner, thanks to an improvement in the dispersion. of the charge in the rubber matrix and a lowering of the viscosity of the compositions, to improve their ability to use in the green state, these agents being for example hydrolysable silanes such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolysable polyorganosiloxanes.
• hydrolysable silanes such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolysable polyorganosiloxanes.
• compositions used in the treads of the tires of the invention may be manufactured in suitable mixers, using two phases of successive preparation well known to those skilled in the art: a first phase of work or thermomechanical mixing (so-called “non-productive” phase) at high temperature, up to a maximum temperature of between 110 ° C. and 190 ° C., preferably between 130 ° C. and 180 ° C., followed by a second mechanical working phase (so-called “productive” phase) to a lower temperature, typically below 110 ° C., for example between 40 ° C. and 100 ° C. , finishing phase during which is incorporated the crosslinking system.
• a first phase of work or thermomechanical mixing at high temperature, up to a maximum temperature of between 110 ° C. and 190 ° C., preferably between 130 ° C. and 180 ° C.
• a second mechanical working phase “productive” phase
• the process for preparing such compositions comprises for example the following steps: thermomechanically kneading (for example in one or more times) the diene elastomer (s) with the reinforcing inorganic filler, the coupling agent, if appropriate the carbon black the plasticizer system and the thermoplastic polyurethane block copolymer with polyurethane blocks and with polydiene blocks, until a maximum temperature of between 110 ° C. and 190 ° C. (so-called "non-productive" phase) is reached;
• the non-productive phase is carried out in a single thermomechanical step in the course of which, in a suitable mixer such as a conventional internal mixer, all the basic constituents (the diene elastomers, the plasticizer system, the reinforcing inorganic filler, the coupling agent and the polyurethane block thermoplastic block copolymer polyurethane and polydiene blocks), then in a second step, for example after one to two minutes of mixing, the others additives, optional load-collectors or processors, with the exception of the crosslinking system.
• the total mixing time, in this non-productive phase is preferably between 1 and 15 min.
• the mixture thus obtained After cooling the mixture thus obtained, it is then incorporated in an external mixer such as a roll mill, maintained at low temperature (for example between 40 ° C and 100 ° C), the crosslinking system. The whole is then mixed (productive phase) for a few minutes, for example between 2 and 15 min.
• an external mixer such as a roll mill, maintained at low temperature (for example between 40 ° C and 100 ° C)
• the whole is then mixed (productive phase) for a few minutes, for example between 2 and 15 min.
• the actual crosslinking system is preferably based on sulfur and a primary vulcanization accelerator, in particular a sulfenamide type accelerator.
• a primary vulcanization accelerator in particular a sulfenamide type accelerator.
• various known secondary accelerators or vulcanization activators such as zinc oxide, stearic acid, derivatives guanidics (especially diphenylguanidine), etc.
• the sulfur content is preferably between 0.5 and 3.0 phr, that of the primary accelerator is preferably between 0.5 and 5.0 phr.
• accelerator any compound capable of acting as a vulcanization accelerator for diene elastomers in the presence of sulfur, especially thiazole type accelerators and their derivatives, thiuram type accelerators, zinc dithiocarbamates.
• accelerators are more preferably selected from the group consisting of 2-mercaptobenzothiazyl disulfide (abbreviated "MBTS”), N-cyclohexyl-2-benzothiazyl sulfenamide (abbreviated “CBS”), N, N-dicyclohexyl-2-benzothiazyl sulfenamide (abbreviated “DCBS”), N-tert-butyl-2-benzothiazylsulfenamide (abbreviated “TBBS”), N-tert-butyl-2-benzothiazylsulfenimide (abbreviated “TBSI”), zinc dibenzyldithiocarbamate (in abbreviated "ZBEC”) and mixtures of these compounds.
• MBTS 2-mercaptobenzothiazyl disulfide
• CBS N-cyclohexyl-2-benzothiazyl sulfenamide
• DCBS N-dicyclohex
• the final composition thus obtained can then be calendered, for example in the form of a sheet, a plate especially for a characterization in the laboratory, or extruded, for example to form a rubber profile used for the manufacture of a tread.
• the invention relates to the tires previously described both in the green state (that is to say, before firing) and in the fired state (that is to say, after crosslinking or vulcanization).
• Composition C 1 is a control composition, based on SBR solution, which can be used in conventional "green tire” treads for passenger vehicles.
• Composition C.2 differs from control composition C 1 only by replacing 20 phr of SBR with 20 phr of a thermoplastic polyurethane block copolymer. Both compositions are further characterized by high levels of reinforcing filler and plasticizer system.
• the overall plasticizer system is a mixture of a hydrocarbon resin (polylimonene resin) and a liquid plasticizer (a sunflower vegetable oil and an SBR MES extension oil).
• the treads of tires comprising compositions C 1 and C 2, respectively, are characterized, after firing, by a transverse adhesion test on a wet ground.
• the tires are mounted, at the front and at the rear, under nominal inflation pressure, on a "SEAT" model vehicle, model “LEON”, equipped with an ABS system.
• the test consists of measuring the minimum time required for the vehicle to travel on a highly virulent circuit, watered in such a way as to keep the ground moist, under (maximum) limit speed conditions. A value lower than that of the control indicates an improved result, ie a shorter travel time.
• the tires of the invention make it possible to appreciably improve the wet grip performance, with a reduced travel time of 2.2% (ie about 2.2 seconds less for a tire). circuit tour for about 100 seconds) compared to the control tires, which is significant for the skilled person.
• thermoplastic polyurethane block copolymer with polyurethane blocks and polydiene blocks, especially in the presence of high filler and plasticizer levels, in the composition of the tread of the tire according to the invention makes it possible to obtain tires having adhesion on improved wet ground.
• Blend of oleic sunflower vegetable oil (“Lubrirob Tod 1880” from Novance), and MES extension oil from SBR ("Catenex SNR” from Shell);
• Silane TESPT (SI69" from Degussa);
• DPG Diphenylguanidine ("Perkacit DPG" from Flexsys);

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• 2010
  • 2010-12-23 FR FR1061110A patent/FR2969631B1/fr not_active Expired - Fee Related
• 2011
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  • 2011-12-19 WO PCT/EP2011/073278 patent/WO2013041151A1/fr not_active Ceased
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