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
  • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/06—Polymer mixtures characterised by other features having improved processability or containing aids for moulding methods
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
  • C08L25/10—Copolymers of styrene with conjugated dienes
• • 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
• • 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
  • C08L71/126—Polyphenylene oxides modified by chemical after-treatment
• • 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
  • C08L9/08—Latex

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 .
• a Japanese document JP 2004-238547 describes a composition comprising particles of micrometric size (10 ⁇ or approximately 45 ⁇ ) of a polyphenylene ether resin, which make it possible to increase the rigidity of the compositions, with a an acceptable increase in the hysteresis of the compositions.
• the polyphenylene ether resin is used in the form of micrometric particles (approximately 10 ⁇ or 45 ⁇ ), and not in the form of a compatible plasticizer, dispersed and intimately mixed with the elastomeric matrix of the composition.
• thermoplastic resin based on optionally substituted polyphenylene ether units can advantageously be used as a plasticizing resin in a composition in which the majority elastomer is a vinylaromatic diene elastomer.
• the use of a plasticizing resin surprisingly makes it possible to improve the compromise of performance between the ease of manufacture of the mixtures and the adhesion of the tires.
• the use of these 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 reduction in the adhesive strength.
• - - raw compositions related to the use of these resins and thus facilitate the manufacture of tires comprising these compositions.
• a first subject of the invention relates to a rubber composition based on at least one vinylaromatic diene elastomer, a reinforcing filler, a crosslinking system, a thermoplastic resin comprising optionally substituted polyphenylene ether units, said resin having a compatibility with said vinylaromatic diene elastomer such as a mixture of said vinylaromatic diene elastomer and said resin generates a composition having less than 10% of its volume in the form of particles larger than 2 microns.
• the invention relates to a composition as defined above, wherein said resin has a compatibility with said vinylaromatic diene elastomer such that a mixture of said vinylaromatic diene elastomer and said resin generates a composition having less than 5% of its volume in the form of particles larger than 2 microns; more preferably, the compatibility with said vinylaromatic diene elastomer is such that a mixture of said vinylaromatic diene elastomer and said resin generates a composition having less than 2% of its volume in the form of particles larger than 2 microns.
• the invention relates to a composition as defined above, wherein said resin has a compatibility with said vinylaromatic diene elastomer such as the glass transition temperature, Tg, of a mixture of said vinylaromatic diene elastomer. and said resin is increased by more than 5 ° C, preferably by more than 10 ° C for 25 parts by weight per hundred parts by weight of elastomer (phr) of said resin, based on the Tg of said vinylaromatic diene elastomer alone .
• Tg glass transition temperature
• the compatibility with the vinylaromatic diene elastomer such as the Tg of a mixture of said vinylaromatic diene elastomer and said resin is increased by more than 12 ° C. for 25 phr of said resin, with respect to the Tg of said diene elastomer. vinylaromatic alone.
• the invention relates to a composition as defined above, in which the vinylaromatic diene elastomer is chosen from the group consisting of butadiene and styrene copolymers, isoprene and styrene copolymers, and copolymers of butadiene, isoprene and styrene and mixtures of these elastomers, and preferably in the group consisting of copolymers of butadiene and styrene and the mixture thereof.
• the vinylaromatic diene elastomer has a vinylaromatic content greater than 10%, preferably between 15% and - -
• 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, wherein the thermoplastic resin based on optionally substituted polyphenylene ether units has a glass transition temperature (Tg), measured by DSC according to ASTM D3418 standard. of 1999, in a range from 0 to 215 ° C, preferably from 5 to 200 ° C and more preferably from 5 to 185 ° C.
• Tg glass transition temperature
• the invention relates to a composition as defined above, wherein the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising predominantly polyphenylene units of general formula (I):
• R1, R2, R3 and R4 represent independently of each other identical or different groups selected from hydrogen, hydroxy, alkoxy, halogen, amino, alkylamino, dialkylamino or hydrocarbon groups containing at least 2 carbon atoms, optionally interrupted by heteroatoms and optionally substituted; R1 and R3 on the one hand and R2 and R4 on the other hand being able to form together with the carbon atoms to which they are attached one or more rings contiguous to the benzene ring of the compound of formula (I)
• n is an integer in a range from 3 to 300.
• the invention relates to a composition as defined above, in which the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising predominantly polyphenylene units of general formula (I) in which R 1, R2, R3 and R4 represent independently of one another, identical or different groups chosen from:
• linear, branched or cyclic alkyl groups comprising from 1 to 25 carbon atoms (preferably from 2 to 18), optionally interrupted by heteroatoms chosen from nitrogen, oxygen and sulfur, and optionally substituted with hydroxy, alkoxy, amino, alkylamino, dialkylamino, or halogen groups.
• aryl groups comprising from 6 to 18 carbon atoms (preferably from 6 to 12), optionally substituted with hydroxyl, alkoxy, amino, alkylamino, dialkylamino, alkyl or halogen groups,
• the invention relates to a composition as defined above, wherein the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising predominantly polyphenylene units of general formula (I) in which R1, R2 , R3 and R4 independently of one another represent identical or different groups chosen from:
• linear, branched or cyclic alkyl groups comprising from 1 to 12 carbon atoms (preferably from 2 to 6), optionally interrupted by hetero atoms and optionally substituted by hydroxyl or alkoxy groups containing from 1 to 6 carbon atoms, amino, alkylamino having 1 to 6 carbon atoms, dialkylamino having 2 to 12 carbon atoms, or halogen.
• aryl groups comprising from 6 to 18 carbon atoms (preferably from 6 to 12), optionally substituted with hydroxyl groups, alkoxy groups having from 1 to 6 atoms, amino, alkylamino groups having from 1 to 6 atoms, dialkylamino group having from 2 to to 12 carbon atoms, alkyl having 1 to 12 carbon atoms, or halogen.
• the invention relates to a composition as defined above, wherein R1 and R2 represent an alkyl group and in particular a methyl group; and R3 and R4 represent hydrogen atoms. - -
• the invention relates to a composition as defined above, in which the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising predominantly polyphenylene units of general formula (I) in which n is an integer in a range from 3 to 50, preferably from 5 to 30 and more preferably from 6 to 20.
• the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising predominantly polyphenylene units of general formula (I) in which n is an integer in a range from 3 to 50, preferably from 5 to 30 and more preferably from 6 to 20.
• the invention relates to a composition as defined above, in which the thermoplastic resin based on optionally substituted polyphenylene ether units is a compound comprising more than 80% by weight, polyphenylene units of general formula ( I), preferably greater than 95% by weight.
• the invention relates to a composition as defined above, in which the level of said thermoplastic resin based on optionally substituted polyphenylene ether units is in a range from 1 to 90 phr, preferably from 2 to 80 phr, more preferably 3 to 60 phr, more preferably 5 to 60 phr.
• the invention relates to a composition as defined above, in which the reinforcing filler comprises carbon black and / or silica.
• the invention relates to a composition as defined above, in which the reinforcing filler represents between 20 and 250 phr, more preferably between 30 and 180 phr.
• the invention relates to a composition as defined above, wherein the reinforcing filler comprises predominantly carbon black.
• the carbon black represents from 40 to 150 phr, preferably from 50 to 120 phr.
• the invention relates to a composition as defined above, wherein the reinforcing filler comprises predominantly silica.
• the silica represents from 40 to 150 phr, preferably from 50 to 120 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 (trucks, - - tractors, trailers), off-the-road vehicles, agricultural or 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 (trucks, - - tractors, trailers), off-the-road vehicles, agricultural or engineering machinery, aircraft, other transport or handling vehicles.
• the rubber compositions are characterized, before and after firing, 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 ASTM D 5992-96.
• the sample for this measurement Tg is crosslinked with sulfur at a level of about 1.5 phr and N-cyclohexyl benzothiazyl sulphenamide (CBS) at a level of about 2 phr. - -
• the measurements are carried out at 150 ° C with an oscillating chamber rheometer, according to DIN 53529 - Part 3 (June 1983).
• the evolution of the rheometric torque, ACouple, as a function of time describes the evolution of the stiffening of the composition as a result of the vulcanization reaction.
• the measurements are processed according to DIN 53529 - Part 2 (March 1983): To is the induction time, ie the time required for the beginning of the vulcanization reaction; Ta, (for example T99) is the time necessary to reach a conversion of a%, that is to say a% (for example 99%) of the difference between the minimum and maximum couples.
• the measurements are performed under a transmission optical microscope (MOT) on a device from Olympus, reference BX-51.
• the observations are made in bright field mode ("Bright Field") at a magnification of "times 40" (Objective x40 - additional magnification x1 - magnification camera ring x1).
• the images are obtained in black and white by an Olympus DP-50 acquisition camera.
• the field of observation corresponding to an image is 160 ⁇ x 120 ⁇ .
• particle surface rate measurements are performed on a minimum of 10 images.
• the samples observed are obtained by cryomicrotomy at -60 ° C. and with a cutting instruction of 2 ⁇ .
• the compatibility of the PPE resin and the vinylaromatic diene elastomer is predominant, it is understood to mean that this PPE resin does not form a particle in the composition, that is, that is, in a mixture of the PPE resin with the vinylaromatic diene elastomer, there will be observed a composition having less than 10% of its volume in the form of particles having a size greater than 2 microns ( ⁇ ). More preferably, in a mixture of the PPE resin with the vinylaromatic diene elastomer, a composition having less than 5% of its volume in the form of particles having a size greater than 2 microns and preferably less than 2% will be observed. . This observation of the particle rate and their sizes can be done at the MOT as described above.
• a composition in which less than 10% of said resin is in the form of particles having a size greater than 2 micrometers corresponds to a composition in which, if we observe 10 contiguous images on sections of 2 ⁇ at the MOT. as - - described above, we find on average less than 10% of the observed surface corresponding to particles larger than 2 ⁇ .
• the rubber composition according to the invention is based on at least one vinylaromatic diene elastomer, a reinforcing filler, a crosslinking system, a thermoplastic resin comprising optionally substituted polyphenylene ether units, said resin having a compatibility with said vinylaromatic diene elastomer such as a mixture of said vinylaromatic diene elastomer and said resin generates a composition having less than 10% of its volume in the form of particles larger than 2 microns.
• composition based is meant 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 rubber composition according to the invention comprises a vinylaromatic diene elastomer predominate.
• elastomer or “diene” rubber must 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;
• conjugated dienes 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, 2-methyl-3-isopropyl 1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene.
• 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).
• alkoxysilane groups such as as described for example in FR 2,765,882 or US 5,977,2308
• carboxylic groups as described for example in WO 01/92402 or US 6,815,473, WO 2004/096865 or US 2006/0089445
• polyethers as described for example in EP 1 127 909 or US Pat. No. 6,503,973
• vinylaromatic diene elastomers such as SBR
• SBR vinylaromatic diene elastomers
• the vinylaromatic diene elastomer of the composition in accordance with the invention has a vinylaromatic content greater than 10%, preferably between 15% and 60%, more preferably between 20% and 50%, so that very preferably between 30 and 50% and even more preferably between 35 and 50%.
• 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 of greater than 10%, preferably between 15% and 50%, more preferably between 20% and 50%, very preferably between 30 and 50% and even more preferably between 35 and 50%.
• the vinylaromatic diene elastomer of the composition according to the invention has a vinylaromatic content of between 10% and 30%, preferably between 12% and 28%, more preferably between 14% and 20%. More preferably, the vinylaromatic diene elastomer of the composition in accordance with the invention is a styrenic diene elastomer (that is to say that the vinylaromatic part is a styrene part), with a styrene content of between 10% and 30%. preferably between 12% and 28%, more preferably between 14% and 20%.
• the vinylaromatic diene elastomer of the composition according to 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 of between 10% and 60% by weight and more particularly between 20% and 50%, a content (mol%) in -1,2 bonds of the butadiene part. between 4% and 75%, a content (mol%) of trans-1,4 bonds between 10% and 80%.
• SBR butadiene-styrene 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 D3418 standard of 1999, between 25 ° C and -50 ° C.
• SBIR butadiene-styrene-isoprene copolymers
• SBIR butadiene-styrene-isoprene copolymers
• 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”).
• ESBR emulsion
• SSBR prepared in solution
• an SBR having an average styrene content for example between 25 and 50% by weight, preferably between 35% and 50% by weight, is used.
• 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 level is 100 phr, that is to say that it can not be used. 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 the manufacture of tires for example an organic filler such as carbon black, an inorganic filler, may be used.
• an organic filler such as carbon black
• an inorganic filler may be used.
• Reinforcing such as silica, or a blend of these two types of filler, including a black carbon and silica blend.
• carbon blacks are suitable for all carbon blacks, including the black type HAF, ISAF, SAF conventionally used in tires (so-called pneumatic grade black).
• HAF black type HAF
• ISAF ISAF
• SAF conventionally used in tires
• 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 (regardless of 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 of 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, especially any precipitated or pyrogenic silica having a surface - -
• 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 the predominant reinforcing filler between 60 and 160 phr, more preferably between 70 and 150 phr.
• silica is used as reinforcing filler majority 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 at least bifunctional for ensuring 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” 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);
• 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 polysulfides (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 polysulfides of bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl).
• TESPT bis (3-triethoxysilylpropyl) tetrasulfide
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide
• polysulfides in particular disulfides, trisulphides or tetrasulfides
• bis (monoalkoxyl (C1-C4) - - dialkyl (C1 -C4) silylpropyl) more particularly the bis-monoethoxydimethylsilylpropyl tetrasulfide as described in the patent application WO 02/083782 (or US 2004/132880).
• 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 thermoplastic resin based on optionally substituted polyphenylene ether units (abbreviated as "EPP resin”).
• EPP resin optionally substituted polyphenylene ether units
• 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 215 ° C., preferably from at 200 ° C and more preferably from 5 to 185 ° C. Below 0 ° C, the EPP resin does not allow a shift of sufficient Tg in the composition comprising it and above 215 ° C, one can meet manufacturing problems including to obtain a homogeneous mixture.
• Tg glass transition temperature
• the PPE resin is a compound comprising predominantly polyphenylene units of general formula (I):
• R1, R2, R3 and R4 represent independently of each other identical or different groups selected from hydrogen; hydroxy, alkoxy, halogen, amino, alkylamino, dialkylamino groups; hydrocarbon groups containing at least 2 carbon atoms, optionally interrupted by hetero atoms and optionally substituted; R1 and R3 on the one hand and R2 and R4 on the other hand can form together with the carbon atoms to which they are attached one or more rings contiguous to the benzene ring of the compound of formula (I)
• n is an integer in a range from 3 to 300.
• R1, R2, R3 and R4 represent independently of each other identical or different groups chosen from:
• linear, branched or cyclic alkyl groups comprising from 1 to 25 carbon atoms (preferably from 2 to 18), optionally interrupted by heteroatoms chosen from nitrogen, oxygen and sulfur, and optionally substituted with hydroxy, alkoxy, amino, alkylamino, dialkylamino, or halogen groups.
• aryl groups comprising from 6 to 18 carbon atoms (preferably from 6 to 12), optionally substituted with hydroxyl, alkoxy, amino, alkylamino, dialkylamino, alkyl or halogen groups,
• R1, R2, R3 and R4 independently of one another represent identical or different groups chosen from:
• linear, branched or cyclic alkyl groups comprising from 1 to 12 carbon atoms (preferably from 2 to 6), optionally interrupted by hetero atoms and optionally substituted by hydroxyl or alkoxy groups containing from 1 to 6 carbon atoms, amino, alkylamino having 1 to 6 carbon atoms, dialkylamino having 2 to 12 carbon atoms, or halogen.
• aryl groups comprising from 6 to 18 carbon atoms (preferably from 6 to 12), optionally substituted with hydroxyl groups, alkoxy groups having from 1 to 6 atoms, amino, alkylamino groups having from 1 to 6 atoms, dialkylamino group having from 2 to to 12 carbon atoms, alkyl having 1 to 12 carbon atoms, or halogen.
• R1 and R2 represent an alkyl group and in particular a methyl group; and R3 and R4 represent hydrogen atoms.
• the PPE resin is a poly (2,6-dimethyl-1,4-phenylene ether).
• n is an integer comprised in a range from 3 to 50, more preferably from 5 to 30, preferably from 6 to 20.
• the EPP resin is a compound comprising more than 80% by weight, and even more preferably more than 95% by weight, polyphenylene units of general formula (I).
• PPE resins have variable number average molecular weights (Mn), most often from 15,000 to 30,000 g / mol, in the case of high masses such as these, the Mn is measured in such a way that known to those skilled in the art by SEC (also named GPC, as in reference US4588806, column 8).
• Mn number average molecular weight
• SEC also named GPC, as in reference US4588806, column 8
• a PPE resin having a mass Mn less than the masses regularly encountered, and in particular less than 6000 g / mol is preferred.
• the number-average molecular weight (Mn) of PPE with a mass of less than 6000 g / mol is measured by NMR, the conventional measurement by SEC not being sufficiently precise. This measurement by NMR is carried out in a manner known to those skilled in the art, either by assaying the end-of-the-chain functions or by assaying the polymerization initiators, as explained, for example, in "Application of NMR spectroscopy in molecular weight determination of polymers "of Subhash C. Shit and Sukumar Maiti in” European Polymer Journal "vol.22, No. 12, pages 1001-1008 (1986).
• the vinylaromatic diene elastomer has a vinylaromatic content of between 10% and 30%, preferably between 12% and 28%, more preferably between 14% and 20%.
• a PPE resin having a mass Mn less than the masses regularly encountered and in particular less than 2200 g / mol, preferably less than 2000 g / mol and in particular a Mn ranging from 700 to 2000 g / mol.
• the PPE resin useful for the purposes of the invention is compatible with the vinylaromatic diene elastomer of the composition.
• the term "compatible" means that this PPE resin does not form particles in the composition, that is to say that a resin which, in mixture with the vinylaromatic diene elastomer will composition having less than 10% of its volume in the form of particles of a size greater than 2 micrometers, preferably less than 5% and more preferably less than 2%.
• the measurement method, in the MOT, is described previously.
• this PPE resin is compatible with the vinylaromatic diene elastomer in such a way that it is capable of increasing the Tg of the elastomer, that is to say that it will allow at the glass transition temperature, Tg, of a mixture of said vinylaromatic diene elastomer and said resin to increase by more than 5 ° C, preferably more than 10 ° C, preferably more than 12 ° C for 25 parts by weight per hundred parts by weight of elastomer (phr) of said resin, based on the Tg of said vinylaromatic diene elastomer alone.
• 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. II.4.
• Crosslinking system
• 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 primary accelerator).
• primary vulcanization accelerator preferably 0.5 to 10.0 pce 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, in particular 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 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 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, such as, for example, pigments, protection such as anti-ozone waxes, chemical antiozonants, 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 that are capable in a known manner, by means of an improvement. of the dispersion of the filler in the rubber matrix and a lowering of the viscosity of the compositions, to improve their ability to implement in the green state, these agents being, for example, hydrolysable silanes such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolyzable polyorganosiloxanes.
• hydrolysable silanes such as alkylalkoxysilanes, polyols, polyethers, primary, secondary or tertiary amines, hydroxylated or hydrolyzable 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:
• the reinforcing filler in particular the vinylaromatic diene elastomer, during a first stage (so-called “non-productive" stage), the reinforcing filler, the PPE resin and any other ingredients of the composition with the exception of crosslinking system, 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 (the elastomers, the reinforcing filler, the EPP resin and others), then in a second - - time, for example after one to two minutes of mixing, other additives, optional load-collecting agents or additional implementation, 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, 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, made of 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 can 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 sidewall of the tire.
• composition of the invention may advantageously be used in the tread of the tire.
• the mixture is introduced into an internal mixer (final filling rate: approximately 70% by volume), the initial batch temperature of which is approximately 60.degree. vinylaromatic diene elastomer, the reinforcing filler and the EPP resin, as well as the various other ingredients with the exception of the vulcanization system.
• Thermomechanical work (non-productive phase) is then carried out in one step, which lasts in total about 3 to 4 min, 0 until reaching a maximum temperature of "fall" of 180 ° C.
• 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. .
• Control compositions C1, C2 and C3 are conventional compositions for those skilled in the art, used to manufacture tire tread mixtures.
• compositions of the invention C4 to C6 contain a thermoplastic resin based on optionally substituted polyphenylene ether units (abbreviated as "PPE resin"), replacing the plasticizing resin C5 / C9 cutting usual for the man of art and used in witnesses C2 and C3.
• PPE resin optionally substituted polyphenylene ether units
• Zinc oxide (industrial grade - Umicore company);
• compositions according to the invention thanks to this plasticizing effect superior to conventional plasticizing resins, it is possible to reduce the resin content used and thereby reduce the raw tackiness induced by the plasticizing resins and therefore to facilitate the manufacture of mixtures.
• Example 2 is complementary illustrations of the invention in rubber compositions in which the nature of the vinylaromatic diene elastomer and the nature of the filler vary.
• Example 2 shows compositions in which the carbon black is the majority reinforcing filler, while Example 3 shows compositions in which the silica is the majority reinforcing filler.
• the vinylaromatic diene elastomer has a Tg of -48.degree. - -
• Zinc oxide (industrial grade - Umicore company);
• the vinylaromatic diene elastomer has a Tg of -25.degree.
• N-cyclohexyl benzothiazyl sulphenamide (Santocure CBS from Flexsys). - -

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