Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L7/00—Compositions of natural rubber
• • 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
  • B60C1/0025—Compositions of the sidewalls
• • 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
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/0016—Plasticisers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
  • C08L23/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
• • 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
• • 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
  • C08L91/06—Waxes
• • 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
  • C08K2201/00—Specific properties of additives
  • C08K2201/002—Physical properties
  • C08K2201/006—Additives being defined by their surface area
• • 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
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend

Definitions

• Pneumatic tire having an external flank whose composition comprises a hydrocarbon resin
• the present invention relates to pneumatic tires and more particularly to external tire flanks, that is to say, by definition, the elastomeric layers located radially outside the tire, which are in contact with the tire. 'ambiant air.
• the inner area of the tire that is to say the area between the outer and inner zones.
• This zone includes layers or plies which are here called internal layers of the tire. These are, for example, carcass plies, tread sub-layers, tire belt plies or any other layer that is not in contact with the ambient air or the inflation gas of the tire.
• composition of a tire sidewall must have many characteristics that are sometimes difficult to reconcile, and in particular good ozone resistance, low rolling resistance and plasticity before baking allowing manufacture. easy tire (processability).
• compositions traditionally used for sidewalls are based on natural rubber and synthetic rubber such as polybutadiene, and carbon black.
• the anti-ozone wax has the disadvantage of migrating outwards flanks, causing whitish spots that penalize the aesthetics of the tires. This phenomenon is called efflorescence. It is therefore interesting for the tire industry to have flank compositions presenting both the technical properties of ozone resistance, low rolling resistance and processability, without this blooming penalizing the aesthetics of the flanks. pneumatic. In this context, a solution provided by the applicants and to obtain tires that have the technical and aesthetic properties discussed above, is to use new sidewall compositions as explained below.
• the invention now proposed relates to a tire provided with an outer flank, said outer flank comprising at least one composition based on at least 30 to 60 phr of isoprene elastomer, 40 to 70 phr. butadiene elastomer, 10 to 70 phr of carbon black, 5 to 25 phr of hydrocarbon resin mainly composed of units derived from monomers C5, 1.2 to 10 phr of anti-ozone wax, and a crosslinking system.
• the invention relates more particularly to pneumatic tires intended to equip motor vehicles of tourism type, SUV ("Sport Utility Vehicles"), or two wheels (including motorcycles), or aircraft, or industrial vehicles selected from vans, "heavy vehicles” - that is, metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles such as agricultural or civil engineering vehicles - and others transport or handling vehicles.
• SUV Sport Utility Vehicles
• industrial vehicles selected from vans, "heavy vehicles” - that is, metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles such as agricultural or civil engineering vehicles - and others transport or handling vehicles.
• composition based on is meant a composition comprising the mixture and / or the reaction product in situ of the various basic constituents used, some of these constituents being able to react and / or being intended to react. between them, at least partially, during the various phases of manufacture of the composition, or during the subsequent firing, modifying the composition as it was initially prepared.
• the compositions as implemented for the invention may be different in the uncrosslinked state and in the crosslinked state.
• 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 polymer representing the largest mass relative to the total mass of the polymers in the composition.
• a so-called majority charge is that representing the largest mass among the charges of the composition. For example, in a system comprising a single polymer, it is the majority within the meaning of the present invention; and in a system comprising two polymers, the majority polymer accounts for more than half of the mass of the polymers.
• a “minor” compound is a compound that does not represent the largest mass fraction among compounds of the same type.
• a "majority" unit (or monomer) within the same compound (or polymer) in the sense of the present invention, it is understood that this unit (or monomer) is predominant among the units (or monomers) forming the compound (or polymer), that is to say it is the one that represents the largest fraction, by mass among the units (or monomers) forming the compound (or polymer).
• a resin consisting predominantly of units derived from C5 monomers is a resin in which the C5 units represent the largest quantity by mass, among all the units composing said resin.
• a “majority” monomer or a set of “majority” monomers is a monomer (or a set of monomers) that represents the largest mass fraction in the polymer.
• a “minor” monomer is a monomer that does not represent the largest mole fraction in the polymer.
• the compounds mentioned in the description may be of fossil origin or biobased. In the latter case, they can be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass. These include polymers, plasticizers, fillers, etc.
• the tire according to the invention has the essential feature of being provided with an external sidewall, said outer side comprising at least one composition based on at least 30 to 60 phr of isoprene elastomer, 40 to 70 phr. butadiene elastomer, 10 to 70 phr of carbon black, 5 to 25 phr of hydrocarbon resin mainly composed of units derived from monomers C5, 1.2 to 10 phr of anti-ozone wax, and a crosslinking system.
• elastomer and "rubber” are used interchangeably in the text.
• elastomer or “diene” rubber it is to be understood in a known way (one or more elastomers) is understood to come from at least a part (ie a homopolymer or a copolymer) of diene monomers (monomers carrying two double bonds). carbon-carbon, conjugated or not).
• diene elastomers can be classified in two categories: "essentially unsaturated” or "essentially saturated”.
• essentially unsaturated is generally understood to mean a diene elastomer derived at least in part from conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (% by weight). mole).
• conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (% by weight). mole).
• conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (% by weight). mole).
• conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (% by weight). mole).
• highly unsaturated diene elastomer is particularly understood to mean a diene elastomer having a content of units of diene origin (conjugated dienes) which is greater than 50%.
• diene elastomers such as certain butyl rubbers or copolymers of dienes and alpha-o lé fine type EPDM can be qualified as "substantially saturated" diene elastomers (diene origin ratio). low or very low, always less than 15%).
• diene elastomer essentially unsaturated may be used in the external flanks according to the invention: (a) any homopolymer obtained by polymerization of a conjugated diene monomer having 4 at 12 carbon atoms;
• the composition of the outer flank comprises from 30 to 60 phr of isoprene elastomer, and from 40 to 70 phr of butadiene elastomer.
• isoprene elastomer is meant all elastomers mainly consists of isoprene monomers.
• the isoprene elastomer is selected from the group consisting of isoprene polymers, isoprene copolymers and mixtures thereof.
• isoprene copolymers mention may be made of those comprising, as a co-monomer, a minority, styrene (SIR), butadiene (BIR) or styrene and butadiene (SBIR).
• SIR styrene
• BIR butadiene
• SBIR styrene and butadiene
• isoprene-styrene copolymers and in particular those having a styrene content of between 5% and 50% by weight and a Tg of between -25 ° C. and -50 ° C. are suitable, butadiene copolymers are also suitable.
• butadiene-styrene-isoprene copolymers those having an isoprene content greater than the content of styrene and butadiene, and in particular those having an isoprene content of between 50% and 60% by weight, are suitable as isoprene elastomers. weight. More preferably, the isoprene elastomer is selected from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR) and mixtures thereof. Very preferably, the isoprene elastomer is natural rubber.
• polyisoprenes having a content (mol%) of cis-1,4 bonds of greater than 90%, more preferably still greater than 98%, are preferably used.
• the isoprene elastomer content is in a range from 30 to 55 phr, preferably from 35 to 50 phr.
• butadiene elastomer all elastomers mainly consisting of butadiene monomers.
• the butadiene elastomer is selected from the group consisting of butadiene polymers, butadiene copolymers and mixtures thereof.
• the butadiene copolymers mention may be made of those comprising, as a minor co-monomer, styrene (SBR), isoprene (BIR) or styrene and isoprene (SBIR). All 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 greater than 80% are suitable. >.
• butadiene-styrene copolymers and in particular those having a glass transition temperature, Tg, (measured according to ASTM D3418) between 0 ° C. and -70 ° C. and more particularly between -10 ° C. and - 60 ° C, a 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%) of trans-1,4 bonds of between 10% and 80%.
• Tg glass transition temperature
• Butadiene-isoprene copolymers are also suitable, those having an isoprene content of between 5% and 50% by weight. weight and a Tg of -40 ° C to -80 ° C.
• butadiene-styrene-isoprene copolymers suitable for butadiene elastomer title include those having a butadiene content greater than the content of styrene and isoprene. More preferably, the butadiene elastomer is selected from the group consisting of polybutadiene (BR), butadiene-styrene copolymers (SBR) and mixtures thereof. Very preferably, the butadiene elastomer is polybutadiene.
• the level of butadiene elastomer is in a range from 45 to 70 phr, preferably from 50 to 65 phr.
• the isoprenic and butadiene elastomers are the only elastomers of the composition, which means that the sum of their content in phr is 100 phr.
• composition of the external sidewall of the tire of the invention may comprise other elastomers, and this at a level preferably less than or equal to 30 phr, preferably at a rate of less than or equal to 25. pce, 20 pce or even 15 pce.
• any elastomer known to those skilled in the art and not defined above as isoprenic or butadiene elastomer is usable.
• composition of the outer side of the tire of the invention comprises from 10 to 70 phr of carbon black.
• Any type of carbon black known for its ability to strengthen a rubber composition used for the manufacture of tires can be used.
• carbon blacks are suitable all carbon blacks conventionally used in tires (so-called pneumatic grade black).
• pneumatic grade black For example, mention will be made more particularly of reinforcing carbon blacks of ASTM NI 15, N134, N234, N326, N330, N339, N347, N375 grade or, depending on the intended applications, blacks of higher series (for example N550 , N660, N683, N772), or even N990.
• the carbon blacks could for example already be incorporated into the isoprene elastomer in the form of a masterbatch (see for example applications WO 97/36724). or WO 99/16600).
• specific surface area BET refers to the specific surface area measured according to ASTM D6556-09 (multipoint method (5 points) -gas: nitrogen-relative pressure range ⁇ / ⁇ 0: 0.05 to 0.30].
• 10 to 70 phr of carbon black in the composition of the outer flank, 10 to 70 phr of carbon black, preferably 10 to 45 phr, has a specific surface area greater than 60 m 2 / g, preferably greater than 80m 2 / g. More preferably, 10 to 70 phr of carbon black, preferably 10 to 45 phr, has a specific surface area greater than 90 m 2 / g, preferably greater than 110 m 2 / g.
• the total amount of carbon black is in a range from 20 to 60 phr, preferably from 25 to 55 phr.
• the carbon black is the only reinforcing filler in the composition of the outer sidewall of the tire, preferably the only filler.
• composition of the external sidewall of the tire of the invention may comprise another filler, optionally reinforcing, preferably at a total content of less than 20 phr, more preferably less than 15 phr.
• organic fillers other than carbon blacks
• 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 of alumina (Al 2 O 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
• a coupling agent or bonding agent
• a coupling agent at least bifunctional intended 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.
• non-reinforcing filler mention may be made of those selected from the group consisting of calcium carbonate, kaolin, montmorillonite, aluminum silicate, magnesium silicate and mixtures thereof.
• composition of the external sidewall of the tire of the invention comprises from 5 to 25 phr of hydrocarbon resin mainly composed of units derived from C5 monomers. Indeed, the applicants have found that such a quantity of such a resin allows the sidewall compositions to have an excellent balance of ozone resistance performance, non-efflorescence or absence of efflorescence , low rolling resistance and tire processability.
• monomers C5 is meant according to the present invention and in a conventional manner for the skilled person, the monomers from C4 to C6 petroleum fractions.
• 1,3 pentadienes, cis and trans, pentenes, cyclopentadiene, cyclopentene, pyperylene, isoprene, etc. are suitable.
• the resin useful for the purposes of the invention mainly composed of units derived from C5 monomers, can comprise, in addition to these units, and in a minor way, aliphatic or aromatic units or else of the aliphatic / aromatic type. that is to say based on aliphatic and / or aromatic monomers, other than C5.
• the resin may comprise, as a minority, units derived from C9 monomers.
• This hydrocarbon resin is predominantly composed of units derived from C5 monomers, the resin has an aromatic proton content of less than 20%, preferably less than 15%.
• the hydrocarbon resin useful for the purposes of the invention has an aromatic proton content of less than 5%, preferably less than 0.5%. More preferably, the resin does not comprise an aromatic unit.
• the hydrocarbon resin useful for the purposes of the invention has an aromatic proton content in a range of 7 to 15%, preferably 9 to 13%.
• the hydrocarbon resin useful for the purposes of the invention has an ethylenic proton content of less than 15%, preferably less than 7%, more preferably less than 5%.
• the hydrocarbon resin useful for the purposes of the invention has a glass transition temperature (Tg) in a range from 30 ° C to 80 ° C, preferably 40 to 60 ° C. C.
• the hydrocarbon resin useful for the purposes of the invention has an average molecular weight Mn in a range from 500 g / mol to 3000 g / mol and preferably from 700 to 2000 g / mol.
• the hydrocarbon resin useful for the purposes of the invention has a polymolecularity index (Ip) in a range from 1 to 4, preferably from 1.5 to 3.5, more preferably from 1, 7 to 3.
• Ip polymolecularity index
• the macrostructure (Mw, Mn, Ip and Mz) of the hydrocarbon resin is determined by size exclusion chromatography (SEC) on the basis of ISO 16014 standards (Determination of average molecular mass and molecular mass distribution of polymers using size exclusion chromatography), ASTM D5296 (Molecular Weight Averages molecular weight distribution of polystyrene by High performance size exclusion chromatography), and DIN 55672 (size exclusion chromatography).
• the resin sample is solubilized in non-antioxidized tetrahydrofuran to a concentration of 1.5 g / l.
• the solution is filtered with a Teflon filter with a porosity of 0.45 ⁇ , for example using a disposable syringe fitted with a filter.
• a volume of 100 ⁇ is injected through a set of size exclusion chromatography columns.
• the mobile phase is eluted with a flow rate of 1 ml / min.
• the columns are thermostatically controlled in an oven at 35 ° C.
• the detection is ensured by a refractometer thermostated at 35 ° C.
• the stationary phase of the columns is based on a divinylbenzene polystyrene gel with controlled porosity.
• the polymer chains are separated according to the size they occupy when they are solubilized in the solvent: the more they occupy a large volume, the less accessible the pores of the columns and their elution time is low.
• polystyrene standards with narrow molecular distributions (polymolecularity index, Ip, less than or equal to 1.1) are used.
• the molar mass range of these standards ranges from 160 to about 70,000 g / mol.
• These standards can be grouped by "families" of 4 or 5 standards having an increment of approximately 0.55 in log of M between each.
• PSS kits polymer standard service, reference PSS-pskitrll-3
• PS of Mp. 162 g / mol (Interchim, reference 178952).
• the average molar masses in number (Mn), in mass (Mw), the Mz, and the polydispersity of the analyzed resin are calculated from this calibration curve. This is why we speak of molar masses relative to a polystyrene calibration.
• Ip Mw / Mn with Mw weight average molecular weight, and Mn molecular mass by number. It is also recalled that the masses Mw, Mn and Mz are average masses calculated according to the formulas below:
• Ai is the amplitude of the signal of the refractometric detector corresponding to the mass Mi and to the elution time ti.
• the material used for the SEC measurement is a liquid chromatography chain, for example the WATERS Alliance 2690 chain comprising a pump, a degasser and an injector; a differential refractometer (for example the WATERS refractometer 2410), data acquisition and processing software, for example the WATERS WATOWER software, a column oven, for example the WATERS "columns Heater Module” and 4 mounted columns in series in the following order:
• the aromatic proton level (% HA) and the ethylene proton content (% HE) are measured by 1H NMR. This determination is made with respect to all the detected signals. Thus, the results obtained are expressed as% peak area.
• the samples are solubilized in deuterated chloroform (CDCl 3 ) at a rate of approximately 10 mg of resin in approximately 1 ml of solvent.
• the spectra are acquired on a Bruker 500 MHz Avance spectrometer equipped with a Bruker BBO z-grad 5 mm broadband probe.
• the 1H NMR experiment uses a 30 ° single pulse sequence and a 5 second repetition time between each acquisition. 64 accumulations are performed at room temperature. The chemical shifts are calibrated with respect to the protonated impurity of deuterated chloroform; 1 ppm at 7.20 ppm.
• the 1H NMR signals of the aromatic protons are between 8.5ppm and 6.2ppm.
• Ethylenic protons generate signals between 6.2ppm and 4.5ppm. Finally, the signals corresponding to the aliphatic protons are located between 4.5ppm and Oppm. The areas of each category of protons are referred to the sum of these areas to give a distribution in% of area of each category of protons.
• the glass transition temperature (Tg) is measured according to the ASTM D3418 standard.
• C5 resins are commercially available, for example sold by the company Eastman under the name "Piccotac 1105" or “Imper a RI 507", by the company Exxon under the name “Escorez 1102", by the company Ko Ion under the denomination "Hikorez Al 100” or by Cray Valley Total under the name “Wingtack98”.
• the C5-C9 resins are commercially available, for example sold by Exxon under the name "OPPERA373" by Eastman under the name "Piccotac 8090" by Cray Valley Total under the name “Wingtack STS”. ".
• the amount of hydrocarbon resin is in a range from 7 to 25 phr, more preferably from 9 to 25 phr, or from 8 to 20 phr. more preferably 9 to 20 phr and very preferably 9 to 18 phr.
• the composition of the outer sidewall of the tire of the invention does not include any other resin than the resin C5 described above.
• the composition may comprise in addition another hydrocarbon resin at a level of less than or equal to 15 phr, preferably less than or equal to 10 phr.
• hydrocarbon resin sometimes also called plasticizing resin or thermoplastic resin.
• Hydrocarbon resins are polymers well known to those skilled in the art, essentially based on carbon and hydrogen, which can be used in particular as plasticizers in polymer matrices. They have been described, for example, in the book "Hydrocarbon Resins” by R. Mildenberg, M. Zander and G. Collin (New York, VCH, 1997, ISBN 3-527-28617-9), chapter 5 of which is devoted to their applications, particularly 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.
• these hydrocarbon resins may be natural or synthetic, whether or not based on petroleum (if so, also known as petroleum resins). They are by definition miscible (ie, compatible) with the levels used with the polymer compositions for which they are intended, so as to act as true diluents. Their Tg is preferably greater than 0 ° C., especially greater than 20 ° C. (most often between 30 ° C. and 120 ° 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 (“softening point”), the temperature at which the product, for example in the form of powder, agglutinates. The softening temperature of a hydrocarbon resin is generally about 50 to 60 ° C higher than its Tg value.
• hydrocarbon resins examples include those selected from the group consisting of terpene homopolymer or copolymer resins, phenol terpene resins, C9 homopolymer or copolymer resins, resins, and the like. homopolymer or copolymer of vinylaromatic 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-methylstyrene, ortho-methylstyrene, metamethylstyrene, para-methylstyrene, vinyl-toluene, para-tert-butylstyrene, methoxystyrenes, chlorostyrenes, hydroxystyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene, any vinylaromatic monomer resulting from a C9 cut (or more generally from a C8 to C10 cut).
• the composition of the external sidewall of the tire of the invention does not comprise a plasticizing oil or comprises less than 25 phr.
• the composition of the outer sidewall of the tire of the invention does not include plasticizing oil.
• the composition may comprise a plasticizing oil.
• the amount of plasticizing oil is preferably in a range from more than 0 to 25 phr, preferably from 3 to 15 phr.
• plasticizing oil sometimes also called extension oil, whether of aromatic nature or preferably non-aromatic known for its plasticizing properties vis-à-vis diene elastomers, is usable.
• extension oil At ambient temperature (20 ° C), these oils, more or less viscous, are liquids (that is to say, as a reminder, substances having the ability to eventually take the shape of their container), as opposed in particular to hydrocarbon plasticizing resins which are inherently solid at room temperature.
• plasticizing oils selected from the group consisting of naphthenic oils (low or high viscosity, in particular hydrogenated or not), paraffinic oils, MES oils (Medium Extracted Solvates), TDAE oils (Treated Distillate Aromatic) Extracts), mineral oils, vegetable oils, ethers plasticizers, ester plasticizers, phosphate plasticizers, sulphonate plasticizers and mixtures of these compounds.
• naphthenic oils low or high viscosity, in particular hydrogenated or not
• paraffinic oils MES oils (Medium Extracted Solvates)
• TDAE oils Teated Distillate Aromatic Extracts
• mineral oils mineral oils
• vegetable oils ethers plasticizers, ester plasticizers, phosphate plasticizers, sulphonate plasticizers and mixtures of these compounds.
• ethers plasticizers ester plasticizers
• phosphate plasticizers phosphate plasticizers
• sulphonate plasticizers and mixtures of these compounds.
• non-aqueous and non-water-soluble 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, sebacates, triesters of glycerol and mixtures of these compounds.
• glycerol triesters preferably consisting predominantly (for more than 50%, more preferably for more than 80% by weight) of an unsaturated C 8 fatty acid, that is to say selected from the group consisting of oleic acid, linoleic acid, linolenic acid and mixtures of these acids. More preferably, whether of synthetic or natural origin (for example vegetable oils of sunflower or rapeseed), the fatty acid used is more than 50% by weight, more preferably still more than 80% by weight. % by weight of oleic acid.
• Such high oleic acid triesters (trioleates) are well known and have been described, for example, in application WO 02/088238, as plasticizers in tire treads.
• the composition of the external sidewall of the tire of the invention comprises from 1.2 to 10 phr of anti-ozone wax.
• the anti-ozone waxes are well known to those skilled in the art. These anti-ozone-sensitive waxes may be, for example, paraffin waxes, microcrystalline waxes or mixtures of paraffinic and microcrystalline waxes. They consist of a mixture of linear alkanes and non-linear alkanes (iso-alkanes, cycloalkanes, branched alkanes) derived from petroleum refining or the catalytic hydrogenation of carbon monoxide (Fisher Tropsch Process) comprising predominantly chains of at least 20 carbon atoms.
• antiozonant waxes known to those skilled in the art can be used, including natural waxes such as Candelilla wax or Carnauba wax. These waxes can also be used in blends. There may be mentioned commercial waxes “Varazon 4959” or “Varazon 6500” or “Varazon 6810” from Sasol, “Ozoace 0355” from Nippon Seiro, "Negozone 9343” from H & R, "H3841 From Yanggu Huatai company.
• the anti-ozone wax contains from 50% to 75% linear alkanes having 30 carbon atoms to 38 carbon atoms, based on the total amount of linear alkanes.
• the amount of anti-ozone wax is in a range from 1.3 to 5 phr, more preferably from 1.5 to 3 phr.
• the crosslinking system may be a vulcanization system, it is preferably based on sulfur (or sulfur donor) and a primary vulcanization accelerator.
• sulfur or sulfur donor
• a primary vulcanization accelerator To this vulcanization system are optionally added, various known secondary accelerators or vulcanization activators (preferentially for 0.5 to 5.0 phr each) such as zinc oxide, stearic acid, guanidine derivatives (in particular diphenylguanidine), etc.
• Sulfur or a sulfur donor 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 used. is applied to an external tire sidewall.
• the sulfur donors mention may be made, for example, of alkyl phenol disulphides (APDS) such as, for example, para-tert-butylphenol disulphide.
• APDS alkyl phenol disulphides
• 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 outer flank composition described above may furthermore comprise the various additives usually present in the external flanks known to those skilled in the art.
• protective agents such as antioxidants or antiozonants, anti-UV, various processing agents or other stabilizers, or promoters capable of promoting adhesion to the rest of the structure of the pneumatic object.
• the mixture of elastomers with the other components of the outer flank namely carbon black and C5 resin
• the wax as well as the crosslinking system and any other ingredients.
• Those skilled in the art will be able to adapt the order of incorporation of the ingredients (at once or in several successive stages), the temperature and the mixing time. For example, one proceeds for the tests in the following manner: one introduces into an internal mixer, filled to about 70% (more or less 5%) and whose initial temperature of tank is between 40 ° C and 80 ° C, successively elastomers, carbon black, C5 resin, wax and any other ingredients with the exception of the crosslinking system.
• Thermomechanical work non-productive phase
• the mixture thus obtained is recovered, cooled and the crosslinking system is incorporated, for example sulfur and an accelerator on an external mixer (homo-finisher) at 30 ° C., mixing all (productive phase). during a suitable time (for example between 5 and 12 min).
• all the components including the crosslinking system can be introduced successively into the internal mixer as described above.
• the mixture must be up to a temperature of "Fall" less than or equal to 130 ° C, preferably less than or equal to 120 ° C and in particular less than or equal to 110 ° C.
• one or more elastomers (diene and / or thermoplastic) used in the composition may be introduced in the form of "masterbatch” or premixed with some of the components of the composition.
• 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 external tire flanks.
• the outer side described above is particularly well suited for use as a finished product or semi-finished rubber, especially in a tire for a motor vehicle such as a vehicle type two wheels, tourism or industrial.
• the outer side described above is advantageously used in tires of all types of vehicles, especially tourism vehicles or industrial vehicles such as trucks.
• the single appended figure shows very schematically (without respecting a specific scale), a radial section of a tire according to the invention.
• This tire 1 has a top 2 reinforced by a crown reinforcement or belt 6, two outer flanks 3 and two beads 4, each of these beads 4 being reinforced with a rod 5.
• the top 2 is surmounted by a tread not shown in this schematic figure.
• a carcass reinforcement 7 is wound around the two rods 5 in each bead 4, the upturn 8 of this armature 7 being for example disposed towards the outside of the tire 1 which is shown here mounted on its rim 9.
• the carcass reinforcement 7 is in known manner constituted of at least one sheet reinforced by so-called "radial” cables, for example textile or metal, that is to say that these cables are arranged substantially parallel to each other and s' extend from one bead to the other so as to form an angle of between 80 ° and 90 ° with the median circumferential plane (plane perpendicular to the axis of rotation of the tire which is located halfway between the two beads 4 and goes through the middle of the crown frame 6).
• radial cables for example textile or metal
• the inner wall of the tire 1 comprises an airtight layer 10, for example of thickness equal to about 0.9 mm, on the side of the internal cavity 11 of the tire 1.
• the bandage pneumatic according to the invention can use for example for the composition of its outer side as defined above, a composition according to the present invention.
• the tire provided with its outer side as described above is preferably produced before crosslinking (or baking).
• the crosslinking is then carried out conventionally.
• An advantageous manufacturing variant for the skilled person in pneumatic tires, will consist for example in a first step, to lay the airtight layer directly on a garment drum, under the shape of a layer ("skim") of suitable thickness, before covering the latter with the rest of the structure of the tire, according to manufacturing techniques well known to those skilled in the art.
• plasticity is measured according to the ATM standard D1646.
• the value of plasticity is an indicative criterion of industrial performance.
• o Measurements of rolling resistance performance dynamic properties (dynamic shear modulus G * and loss modulus G "
• the dynamic properties G * and G " are measured on a viscoanalyzer (metravib VA4000), according to the ASTM D5992-96 standard.
• the response of a sample of vulcanized composition is recorded (cylindrical test specimen of 2 mm thickness and 79mm 2 of section), subjected to a sinusoidal stress in alternating simple shear, at a frequency of 10 Hz, under normal temperature conditions (23 ° C.) according to ASTM D 1349-09, a strain amplitude sweep is carried out. peak-to-peak of 0.1% to 50% (forward cycle) then 50%> to 0.1% (return cycle) The result exploited is the loss module G ".
• the performance index is the ratio of the value G" of the reference composition to the value G "of the example under consideration.
• the reference with an index 100, a value greater than 100 indicates better rolling resistance performance o Ozone performance measurement
• the ozone resistance of the materials is measured according to the following method: after firing 10 specimens are placed on a trapezium at different elongations ranging from 10%> to 100% in steps of 10%> elongation.
• the so-called B15 specimens are derived from an MFTR plate (called Monsanto) whose two beads located at the ends serve to hold the specimen.
• the so-called B 15 test pieces have the dimensions following 78.5mm * 15mm * 1.5mm.
• the 2.5 mm thick test pieces are baked at 70 ° C for 12 hours in air. They are then baked at 40 ° C under air for 4 weeks. After leaving the oven and exposure at room temperature for 15 min, two successive mechanical stimuli are applied so as to reveal the efflorescence of the wax.
• the first mechanical stimulus consists of a scraping operation of the specimen with a metal blade.
• the second mechanical stimulus consists of an elongation of the specimen at 100% deformation.
• the magnitude of the efflorescence phenomenon (white surface coloration) is then evaluated using a subjective scale of values that is representative of the final appearance of the samples. The values of this subjective scale that were respectively obtained for the samples tested can vary from 0 to 3, and correspond to the "blooming notation". These values ranging from 0 to 3 correspond to the following aspects for the samples:
• External flank compositions containing conventional elastomers, reinforcing fillers and customary additives corresponding to the controls (Tl to T5 Table 1) were prepared according to the methods known to those skilled in the art and similarly to the preparation of the compositions of the invention described above. These control compositions were compared with compositions (C1 to C3 of Table 1) according to the invention.
• Table 1 shows all the compositions of Example 1. The rates are all expressed in phr.
• Carbon black N683 (BET equal to 36m7g, COAN 85ml / 100g)
• compositions were tested according to the previously described tests of efflorescence performance, ozone, rolling resistance and processability.
• Carbon black N683 (BET equal to 36m7g, COAN 85ml / 100g)
• compositions were tested according to the previously described tests of efflorescence performance, ozone, rolling resistance and processability.
• Table 6 shows all the results of Example 3.

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• 2018
  • 2018-06-27 KR KR1020197038118A patent/KR20200022392A/ko not_active Ceased
  • 2018-06-27 US US16/626,958 patent/US20200223259A1/en not_active Abandoned
  • 2018-06-27 CN CN201880043229.XA patent/CN110831780A/zh active Pending
  • 2018-06-27 WO PCT/FR2018/051572 patent/WO2019002764A1/fr not_active Ceased
  • 2018-06-27 EP EP18752800.5A patent/EP3645309A1/de not_active Withdrawn

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