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
• • 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
  • C08K3/011—Crosslinking or vulcanising agents, e.g. accelerators
• • 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
  • C08K3/02—Elements
  • C08K3/04—Carbon
• • 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
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L71/00—Compositions of polyethers obtained by reactions forming an ether link in the main chain; Compositions of derivatives of such polymers
  • C08L71/08—Polyethers derived from hydroxy compounds or from their metallic derivatives
  • C08L71/10—Polyethers derived from hydroxy compounds or from their metallic derivatives from phenols
  • C08L71/12—Polyphenylene oxides
  • C08L71/123—Polyphenylene oxides not modified by chemical after-treatment

Definitions

• the present invention relates to rubber compositions intended in particular for the manufacture of tires or semi-finished products for tires, in particular tire tread rubber compositions having a high ease of manufacture of the mixtures and a good resistance to wear in the tire.
• tires are subjected to many solicitations during their use.
• Tire treads in particular must comply with a large number of technical requirements, which are often antithetical, including high wear resistance and good adhesion, on both dry and wet roads.
• Mixtures for these tires must also have good processability, that is they must be easy to manufacture.
• plasticizers may be plasticizing oils or plasticizing resins, as described in numerous documents, for example in patent applications FR 2866028, FR 2877348 or FR 2889538, describing in particular the use of thermoplastic resins as plasticizing resins .
• the Applicant has described in WO2015 / 091921 a rubber composition based on at least one vinylaromatic diene elastomer, a reinforcing filler, a crosslinking system, a thermoplastic resin comprising polyphenylene ether units optionally. substituted, said resin having a number average molecular weight (Mn) of less than 6000 g / mol.
• Mn number average molecular weight
• the examples provide resins presented with an Mn of 2350 g / mol and 1800 g / mol, for example. This document indicates that the use of such a resin makes it possible surprisingly to improve the compromise of performance between the ease of manufacture of the mixtures and the adhesion of the tires.
• thermoplastic resins based on optionally substituted polyphenylene ether units makes it possible to reduce the amount of resin compared to conventional plasticizing thermoplastic resins, which makes it possible to have a decrease in the raw tackiness of the compositions bonded to the use of these resins and thus facilitate the manufacture of tires comprising these compositions.
• the Applicant has discovered that a particular selection among resins comprising known polyphenylene ether units allowed to further shift the glass transition of the mixture and therefore reduce the amount of conventional thermoplastic resin contained in the mixture.
• a first object of the invention relates to a rubber composition based on at least one vinylaromatic diene elastomer, a reinforcing filler, a crosslinking system, a polyphenylene ether resin having a number average molecular weight.
• Mn in a range from 800 to 1500 g / mol and of general formula (I)
• the invention relates to a composition as defined above, wherein said resin has a number-average molecular weight (Mn) in a range from 800 to 1300 g / mol, more preferably included in a range from 800 to 1100 g / mol.
• Mn number-average molecular weight
• the invention relates to a composition as defined above, in which the vinylaromatic diene elastomer has a vinylaromatic content greater than 10%, preferably between 10% and 50%, more preferably between 10% and 30%, very preferably between 12 and 28% and even more preferably between 14 and 20%.
• the vinylaromatic diene elastomer is chosen from the group consisting of butadiene and styrene copolymers, isoprene and styrene copolymers, butadiene, isoprene and styrene copolymers and mixtures thereof. elastomers, and preferably in the group consisting of butadiene copolymers and styrene and the mixture thereof. Also preferably, the vinylaromatic diene elastomer content is in a range from 70 to 100 phr (parts by weight per hundred parts of elastomer), and more preferably from 85 to 100 phr.
• the invention relates to a composition as defined above, in which the polyphenylene ether resin has a glass transition temperature (Tg), measured by DSC according to the ASTM D3418 standard of 1999, included in a range of ranging from 0 to 130 ° C, preferably from 5 to 1 15 ° C and more preferably from 5 to 100 ° C.
• Tg glass transition temperature
• the invention relates to a composition as defined above, in which the polyphenylene ether resin has the general formula (I) in which the R groups all represent a hydrogen atom or all an identical alkyl radical. .
• the invention relates to a composition as defined above, in which the R groups represent a methyl radical.
• the invention relates to a composition as defined above, in which n is between 7 and 10.
• the invention relates to a composition as defined above, in which the level of said polyphenylene ether resin is in a range from 1 to 90 phr, preferably from 2 to 80 phr, more preferably , from 3 to 60 phr, better from 5 to 60 phr.
• the invention relates to a composition as defined above, wherein the reinforcing filler comprises carbon black and / or silica.
• the invention relates to a composition as defined above, wherein the reinforcing filler represents between 20 and 200 phr, more preferably between 30 and 160 phr.
• the invention relates to a composition as defined above, wherein the reinforcing filler comprises predominantly carbon black.
• the carbon black represents from 60 to 160 phr, preferably from 70 to 150 phr.
• the invention relates to a composition as defined above, wherein the reinforcing filler comprises predominantly silica.
• the silica represents from 60 to 160 phr, preferably from 70 to 150 phr.
• the invention also relates to finished or semi-finished rubber articles comprising a rubber composition according to the invention.
• the invention also relates to tires comprising a rubber composition according to the invention, and in particular the tires in which the tread comprises a rubber composition according to the invention.
• the tires according to the invention are particularly intended for passenger vehicles such as two-wheeled vehicles (motorcycle, bicycle), industrial vehicles chosen from vans, "heavy vehicles” - ie, subway, bus, transport vehicles road transport (trucks, tractors, trailers), off-the-road vehicles, agricultural or civil engineering machinery, aircraft, other transport or handling vehicles.
• passenger vehicles such as two-wheeled vehicles (motorcycle, bicycle), industrial vehicles chosen from vans, "heavy vehicles” - ie, subway, bus, transport vehicles road transport (trucks, tractors, trailers), off-the-road vehicles, agricultural or civil engineering machinery, aircraft, other transport or handling vehicles.
• the rubber compositions are characterized after cooking, as indicated below.
• the dynamic properties G * are measured on a viscoanalyzer (Metravib VA4000), according to the ASTM D 5992-96 standard.
• the response of a sample of vulcanized composition ie cooked to a conversion of at least 90% is recorded (cylindrical specimen 2 mm thick and 78.5 mm 2 section) , subjected to sinusoidal stress in single shear alternates, at the frequency of 10 Hz.
• a temperature sweep is carried out at a constant temperature rise rate of + 1.5 ° C / min at peak-peak shear stress imposed of 0.7 MPa.
• the specimen is stressed in sinusoidal shear at 10 Hz, symmetrically around its equilibrium position.
• the results used are the complex dynamic shear modulus (G * ), the viscous shear modulus (G "), denoted G" (T).
• the glass transition temperature (denoted Tg) corresponds to the temperature at which the observed maximum of G "is observed during the temperature sweep,
• the Tg is defined as the temperature at which the maximum of G "is observed (G” representing in a known manner the viscous part of the shear modulus), during the temperature sweep of a cross-linked sample subjected to a constraint-imposed sinusoidal stress of 0 , 7 MPa and at a frequency of 10 Hz.
• this Tg is measured during the measurement of the dynamic properties, on a viscoanalyzer (Metravib VA4000), according to the ASTM D 5992-96 standard.
• the molecular weight of the EPP resins is measured as indicated below.
• the SEC (Size Exclusion Chromatography) technique makes it possible to separate the macromolecules in solution according to their size through columns filled with a porous gel.
• the macromolecules are separated according to their hydrodynamic volume, the larger ones being eluted first.
• the SEC allows to apprehend the distribution of molar masses of a polymer.
• the equipment used is a chromatographic chain "WATERS alliance".
• the elution solvent is tetrahydrofuran without antioxidant, the flow rate is 1 ml.min-1, the temperature of the system of 35 ° C and the analysis time of 45 min.
• the columns used are a set of four columns AGILENT trade name two "PL GEL MIXED D" and two "PL GEL MIXED E”.
• the injected volume of the solution of the polymer sample is 100 ⁇ l.
• the detector is a differential refractometer "WATERS 2410" and the chromatographic data exploitation software is the "WATERS EMPOWER" system.
• the average molar masses calculated are relative to a calibration curve made from standard polystyrene.
• the rubber composition according to the invention is based on at least one major vinylaromatic diene elastomer, a reinforcing filler, a crosslinking system, a polyphenylene ether resin having a number-average molecular weight (Mn) included in a range from 800 to 1500 g / mol and of general formula (I)
• base-based composition a composition comprising the mixture and / or the reaction product of the various constituents used, some of these basic constituents being capable of or intended to react between they, at least in part, during the various phases of manufacture of the composition, in particular during its crosslinking or vulcanization.
• 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).
• a majority compound is the elastomer representing the largest mass relative to the total mass of the elastomers in the composition.
• a so-called majority charge is that representing the largest mass among the charges of the composition.
• the majority elastomer represents more than half of the mass of the elastomers.
• the rubber composition according to the invention comprises a majority vinylaromatic diene elastomer.
• elastomer or “diene” rubber should be understood in a known manner (one means one or more) elastomer derived at least in part (ie, a homopolymer or a copolymer) of monomers dienes (monomers carrying two double bonds carbon-carbon, conjugated or not).
• vinylaromatic diene elastomer any copolymer obtained by copolymerization of one or more conjugated dienes with each other or with one or more vinyl aromatic compounds having from 8 to 20 carbon atoms;
• 1,3-butadiene 2-methyl-1,3-butadiene, 2,3-di (C 1 -C 5 alkyl) -1,3-butadienes, such as for example 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene and 2-methyl-3-isopropyl.
• vinylaromatic compounds are suitable for example styrene, alphamethylstyrene, ortho-, meta-, para-methylstyrene, the commercial mixture "vinyl-toluene", para-tert-butylstyrene, methoxystyrenes, chlorostyrenes vinylmesitylene, divinylbenzene, vinylnaphthalene.
• 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.
• alkoxysilane groups such as 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) or groups polyethers (as described for example in EP 1 127 909 or US Pat. No. 6,503,973).
• functionalized elastomers mention may also be made of vinylaromatic diene elastomers (such as SBR) of the epoxidized type.
• the vinylaromatic diene elastomer of the composition in accordance with the invention has a vinylaromatic content greater than 10%, preferably between 10% and 50%, more preferably between 10% and 30%, so that very preferential between 12% and 28% and even more preferentially between 14% and 20%.
• the vinylaromatic diene elastomer of the composition according to the invention is a styrenic diene elastomer (that is to say that the vinylaromatic part is a styrene part), with a styrene content greater than 10%, preferably between 10% and 50%, more preferably between 10% and 30%, very preferably between 12% and 28% and even more preferably between 14% and 20%.
• the vinylaromatic diene elastomer of the composition in accordance with the invention is preferably chosen from the group of highly unsaturated styrenic diene elastomers consisting of styrene butadiene copolymers, styrene copolymers of isoprene and mixtures of these. elastomers.
• Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), isoprene-styrene copolymers (SIR) and isoprene-butadiene-styrene copolymers (SBIR).
• butadiene-styrene copolymers and in particular those having a Tg (glass transition temperature) measured by DSC according to the ASTM D3418 standard of 1999 between 20 ° C. and -70 ° C. and more are suitable. particularly between 0 ° C. and -50 ° C., a styrene content greater than 10%, preferably between 10% and 50%, more preferably between 10% and 30%, very preferably between 12% and 28%, and even more preferably between 14% and 20%, and a content (mol%) in -1,2 bonds of the butadiene part of between 4% and 75%, a content (mol%) of trans-1,4 bonds. between 10% and 80%.
• SBR polystyrene copolymers
• Isoprene-styrene copolymers are also suitable, and in particular those having a styrene content of between 15% and 60% by weight and more particularly between 20% and 50% and a Tg, measured by DSC according to the ASTM standard. D3418 from 1999, between 25 ° C and -50 ° C.
• SBIR butadiene-styrene-isoprene copolymers
• SBIR butadiene-styrene-isoprene copolymers
• SBIR is particularly suitable those having a styrene content of between 15% and 50% by weight, more particularly between 20% and 50%, an isoprene content of between 15% and 60% by weight and more particularly between 20% and 50%, a butadiene content of between 5% and 50% by weight and more particularly between 20% and 40%, a content (mol%) in units -1, 2 of the butadiene part of between 4% and 85%, a content (mol%) in trans-1,4 units of the butadiene part of between 6% and 80%, a content (mol%) in units -1, 2 plus -3 , 4 of the isoprenic portion of between 5% and 70% and a content (mol%) in trans units -1, 4 of the isoprenic part of between 10% and 50%, and more generally any butadiene-styrene-isopre
• the vinylaromatic diene elastomer of the composition according to the invention is an SBR.
• the SBR can be prepared in emulsion ("ESBR”) or prepared in solution (“SSBR”).
• compositions of the invention may contain a single vinylaromatic diene elastomer or a mixture of several vinylaromatic diene elastomers, or diene vinylaromatic elastomers, still the majority, which may be used in combination with other elastomers known to man such as, for example, natural rubber (NR) or polybutadiene (BR).
• NR natural rubber
• BR polybutadiene
• the vinylaromatic diene elastomer content is in a range from 70 to 100 phr, more preferably from 85 to 100 phr, and very preferably this rate is 100 phr, that is to say that it does not exceed 100 phr. Only vinylaromatic diene elastomers are present in the composition.
• any type of reinforcing filler known for its ability to reinforce a rubber composition that can be used for manufacturing tires for example an organic filler such as carbon black, a reinforcing inorganic filler such as silica, may be used. or a blend of these two types of filler, including a carbon black and silica blend.
• carbon blacks are suitable for all carbon blacks, including black type HAF, ISAF, SAF conventionally used in tires (so-called pneumatic grade black).
• the reinforcing carbon blacks of the 100, 200 or 300 series for example blacks N 15, N 134, N 234, N 326, N330, N 339, N 347 or N375, or else, according to the targeted applications, the blacks of higher series (for example N660, N683, N772).
• the carbon blacks could for example already be incorporated into an isoprene elastomer in the form of a masterbatch (see for example WO 97/36724 or WO 99/16600).
• organic fillers other than carbon blacks
• any inorganic or mineral filler (whatever its color and its natural or synthetic origin), also called “white” charge, charge “ clear “or” non-black filler “charge as opposed to carbon black, capable of reinforcing on its own, with no other means than an intermediate coupling agent, a rubber composition for the manufacture of pneumatic, in other words able to replace, in its reinforcing function, a conventional carbon black pneumatic grade; such a filler is generally characterized, in known manner, by the presence of hydroxyl groups (-OH) on its surface.
• -OH hydroxyl groups
• reinforcing inorganic filler is present indifferent, whether in the form of powder, microbeads, granules, beads or any other suitable densified form.
• reinforcing inorganic filler also refers to mixtures of different reinforcing inorganic fillers, in particular highly dispersible siliceous and / or aluminous fillers as described below.
• reinforcing inorganic fillers are particularly suitable mineral fillers of the siliceous type, in particular silica (SiO 2 ), or of the aluminous type, in particular alumina (Al 2 0 3 ).
• 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.
• HDS highly dispersible precipitated silicas
• the reinforcing inorganic filler used in particular if it is silica, preferably has a BET surface area of between 45 and 400 m 2 / g, more preferably between 60 and 300 m 2 / g.
• the total reinforcing filler content (carbon black and / or reinforcing inorganic filler such as silica) is between 20 and 200 phr, more preferably between 30 and 160 phr, the optimum being in a known manner.
• the level of reinforcement expected on a bicycle tire is of course less than that required on a tire capable of driving at high speed in a sustained manner, for example a motorcycle tire, a tire for a vehicle for tourism or for commercial vehicles such as Trucks.
• carbon black is used as reinforcing filler majority between 60 and 160 phr, more preferably between 70 and 150 phr.
• silica is used as the predominant reinforcing filler between 60 and 160 phr, more preferably between 70 and 150 phr, and optionally 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 0.1 and 5 phr).
• a coupling agent or bonding agent at least bifunctional designed to ensure a sufficient connection, chemical and / or physical, between the inorganic filler (surface of its particles) and the diene elastomer, in particular organosilanes or bifunctional polyorganosiloxanes.
• 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).
• x is an integer of 2 to 8 (preferably 2 to 5);
• - A is a divalent hydrocarbon radical (preferably C 1 -C 18 alkylene groups or C 6 -C 12 arylene groups, more particularly C 1 -C 10 alkylenes, especially C 1 -C 4 alkylenes, in particular propylene);
• Z is one of the following formulas:
• R2 R2 in which:
• radicals R1, substituted or unsubstituted, which are identical to or different from one another, represent a C1-C18 alkyl, C5-C18 cycloalkyl or C6-aryl group;
• C 18 (preferably C 1 -C 6 alkyl, cyclohexyl or phenyl groups, especially C 1 -C 4 alkyl groups, more particularly methyl and / or ethyl).
• the radicals R2 substituted or unsubstituted, identical or different from each other, 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 -C 8 cycloalkoxyls, more preferentially still another group chosen from C 1 -C 4 alkoxyls, in particular methoxyl and ethoxyl).
• polysulphurized silanes By way of examples of polysulphurized silanes, mention may be made more particularly of polysulphides (in particular disulfides, trisulphides or tetrasulfides) of bis- (C 1 -C 4 alkoxyl) -alkyl (C 1 -C 4) alkyl-silyl (C 1 -C 4) )), such as, for example, bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl) polysulfides.
• polysulphides in particular disulfides, trisulphides or tetrasulfides
• bis-3-trimethoxysilylpropyl or bis (3-triethoxysilylpropyl
• TESPT bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• POS polyorganosiloxanes
• silanes or POS bearing groupings azo-dicarbonyl functional groups as described for example in patent applications WO 2006/125532, WO 2006/125533, WO 2006/125534.
• the content of coupling agent is preferably between 4 and 16 phr, more preferably between 5 and 15 phr.
• composition according to the invention comprises a polyphenylene ether resin (abbreviated as "EPP resin”).
• EPP resin polyphenylene ether resin
• the EPP resins usually have variable number average molecular weights (Mn), usually from 15,000 to 30,000 g / mol, in the case of high masses such as these, the Mn is measured from a manner known to those skilled in the art by SEC (also named GPC, as in reference US4588806, column 8).
• Mn number average molecular weights
• a PPE resin having a mass Mn less than the masses regularly encountered and in particular ranging from 800 to 1500 g / mol, preferably from 800 to 1300 g / mol and in particular Mn within a range of 800 to 1100 g / mol.
• Molecular weights are measured according to the method described above.
• EPP resins may correspond to EPP resins, according to the sequence of the monomers.
• Formulas of type A and B are examples and other structures of EPP resins are possible.
• PPE resins of type A and B having a low molecular weight can be obtained starting from higher molecular weight commercial EPPE resins, such as "Noryl SA 120" and “Noryl SA90” by a selective extraction of low masses. Molecules contained in these products. This selective extraction was carried out by prior solubilization in a good solvent of the products and followed by a controlled precipitation by the addition of a bad solvent.
• the resin has the general formula (I), of the type
• the groups R represent, independently of one another, a hydrogen atom or an alkyl radical; preferably the R groups all represent a hydrogen atom or all an alkyl radical (preferably methyl, ethyl, propyl or butyl), and more preferably, the R groups represent a methyl radical.
• n is between 6 and 12, preferably between 7 and 10.
• the PPE resin useful for the purposes of the invention preferably has a glass transition temperature (Tg), measured by DSC according to the ASTM D3418 standard of 1999, in a range from 0 to 130 ° C., preferably from at 15 ° C and more preferably from 5 to 100 ° C.
• Tg glass transition temperature
• the level of PPE resin in the composition is preferably in a range from 1 to 90 phr, more preferably from 2 to 80 phr, more preferably from 3 to 60 phr and very preferably from 5 to 60 phr. 11.4.
• the crosslinking system may be a vulcanization system, it is preferably based on sulfur or sulfur donors and primary vulcanization accelerator (preferably 0.5 to 10.0 pce of primary accelerator).
• primary vulcanization accelerator preferably 0.5 to 10.0 pce of primary accelerator
• various known secondary accelerators and / or vulcanization activators such as zinc oxide (preferentially for 0.5 to 10.0 phr), stearic acid or others.
• Sulfur is used at a preferential rate of between 0.5 and 10 phr, more preferably between 0.5 and 5.0 phr, for example between 0.5 and 3.0 phr, when the invention is applied to a strip. of tire rolling.
• 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, dithiocarbamates of zinc.
• 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 sulphenamide (abbreviated “DCBS”), N-tert-butyl-2-benzothiazyl sulphenamide (abbreviated “TBBS”), N-tert-butyl-2-benzothiazyl sulphenimide (abbreviated “TBSI”), zinc dibenzyldithiocarbamate (in abbreviated “ZBEC”) and mixtures of these compounds.
• MBTS 2-mercaptobenzothiazyl disulfide
• CBS N-cyclohexyl-2-benzothiazyl sulfenamide
• DCBS N-dicyclohexy
• the tread rubber compositions according to the invention also comprise all or part of the usual additives usually used in elastomer compositions intended for the production of treads, for example pigments, protection such as anti-ozone waxes, anti-ozonants chemicals, anti-oxidants, anti-fatigue agents, reinforcing resins or plasticizers.
• this plasticizer is a solid hydrocarbon resin other than the previously described resin (or plasticizing resin), an extender oil (or plasticizing oil), or a mixture of both.
• compositions may also contain, in addition to the coupling agents, coupling activators, inorganic charge-covering agents or, more generally, processing aid agents capable of in a known manner, by improving the dispersion of the filler in the rubber matrix and by lowering the viscosity of the compositions, to improve their ability to use in the green state, these agents being, for example, silanes hydrolysable agents such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolysable polyorganosiloxanes.
• silanes hydrolysable agents such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolysable polyorganosiloxanes.
• compositions used in the treads of the invention may be manufactured in appropriate mixers, using two successive preparation phases well known to those skilled in the art: a first phase of work or thermomechanical mixing (phase so-called “non-productive”) at a high temperature, up to a maximum temperature of between 1 10 ° C and 190 ° C, preferably between 130 ° C and 180 ° C, followed by a second phase of mechanical work (phase so-called “productive") to a lower temperature, typically below 1 10 ° C, for example between 40 ° C and 100 ° C, finishing phase during which the crosslinking system is incorporated.
• a first phase of work or thermomechanical mixing phase so-called “non-productive”
• a second phase of mechanical work phase so-called “productive”
• compositions comprising, for example, the following steps:
• non-productive the reinforcing filler, the EPP resin and any other ingredients of the composition with the exception of the system crosslinking, thermomechanically kneading the whole (for example in one or more times), until a maximum temperature of between 1 10 ° C and 190 ° C;
• the non-productive phase is conducted in a single thermomechanical step during which is introduced, in a suitable mixer such as a conventional internal mixer, in a first step all the basic constituents necessary (elastomers, reinforcing filler, EPP resin and others), then a second time, for example after one to two minutes of mixing, the other additives, optional additional charge-recovery or processing agents, with the exception of the crosslinking system.
• the total mixing time in this non-productive phase is preferably between 1 and 15 minutes.
• 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.
• 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 manufacturing of a tire.
• the invention relates to the tires and the semi-finished products for tires previously described, the rubber articles both in the raw state (that is to say, before cooking) and in the cooked state (c '). that is, after crosslinking or vulcanization).
• the rubber composition according to the invention can be used in different parts of the tire, in particular in the crown, the carcass, the bead zone, the sidewall zone and the tread (including in particular the underlayer of the tire. the tread).
• the rubber composition described above can be used in the tire as a rigid elastomeric layer in at least a portion of the tire.
• elastomeric layer is meant any three-dimensional element, in rubber composition (or “elastomer”, both of which are considered to be synonymous), of any shape and thickness, in particular sheet, strip, or other element of any straight section, for example rectangular or triangular.
• the elastomer layer may be used as a tread sub-layer disposed in the crown of the tire, on the one hand between the tread, Le., The portion intended to come into contact with the tread. road during taxiing, and secondly the belt reinforcing said vertex.
• the thickness of this elastomeric layer is preferably in a range from 0.5 to 10 mm, especially in a range of 1 to 5 mm.
• the rubber composition according to the invention may be used to form an elastomeric layer, disposed in the region of the region of the bead of the tire, radially between the carcass ply, the bead and the overturning of the carcass ply.
• Another preferred embodiment of the invention may be the use of the composition according to the invention to form an elastomeric layer disposed in the area of the tire sidewall.
• composition of the invention may advantageously be used in the tread of the tire.
• Thermomechanical work (non-productive phase) is then carried out in one step, which lasts in total about 3 to 4 min, until a maximum temperature of "fall" of 180 ° C is reached.
• the mixture thus obtained is recovered, cooled and then sulfur is incorporated, a sulfenamide type accelerator on a mixer (homo-finisher) at 30 ° C, mixing the whole (productive phase) for a suitable time (by example between 5 and 12 min).
• compositions thus obtained are then calendered either in the form of plates (thickness of 2 to 3 mm) or thin sheets of rubber for the measurement of their physical or mechanical properties, or extruded in the form of a profile. III.2. Testing of rubber compositions
• composition C1 below does not include PPE resin.
• Control compositions C2, C3 and C4 comprise PPE resins not in accordance with the present invention.
• the composition C5 is in accordance with the invention.
• Tables 1 and 2 below The formulations (in phr or parts by weight per hundred parts of elastomer) and their mechanical properties have been summarized in Tables 1 and 2 below.
• TESPT coupling agent "SI69" from Evonik
• Zinc oxide (industrial grade - Umicore company);
• compositions C2 and C3 have glass transition temperatures close to and higher than that of the composition C1 free of high Tg plasticizer.
• the transition to a lower Mn of a type B PPE resin has little effect on modifying the Tg of the mixture.
• C5 it can be seen in C5 that for the Type A PPE resin a decrease in the Mn leads to a much greater increase in the Tg of the mixture.
• the C5 composition according to the invention has a much higher Tg than the C4 composition, whereas the PPE resins contained in these compositions have a comparable molecular mass.

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• Polymers & Plastics (AREA)
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• Engineering & Computer Science (AREA)
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• 2018
  • 2018-10-17 EP EP18808419.8A patent/EP3697840B1/fr active Active
  • 2018-10-17 WO PCT/FR2018/052585 patent/WO2019077272A1/fr not_active Ceased
  • 2018-10-17 US US16/757,597 patent/US20210230401A1/en not_active Abandoned
  • 2018-10-17 JP JP2020521901A patent/JP7222988B2/ja active Active

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