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
  • C08L21/00—Compositions of unspecified rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • 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
  • 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
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group

Definitions

• diene elastomer in known manner an elastomer derived at least in part (homopolymer or copolymer) from diene monomers (monomers carrying two carbon-carbon double bonds, conjugated or not).
• the or each diene elastomer of the composition according to the invention is preferably "highly unsaturated", that is to say that it is derived from conjugated diene monomers having a molar level of units derived from conjugated dienes which is greater than 50%.
• said elastomer has a number-average molecular mass Mn ranging from 500 g / mol to 1500 g / mol.
• said elastomer has a polymolecularity index Ip of less than 2 and, even more preferably, an Ip index of less than 1.5, or even less than 1.2. Also preferably, said elastomer has a glass transition temperature
• one or more diene elastomers each having a temperature Tg between -110 ° C and -80 ° C.
• said composition comprises said diene elastomer (s) of Tg between -65 ° C and -10 ° C in an amount of 100 phr.
• said composition comprises cutting said diene elastomer (s) of Tg between -65 ° C and -10 ° C and said diene elastomer (s) of Tg between -110 ° C and -80 ° C.
• said composition further comprises, in an amount ranging from 20 phr to 40 phr, a plasticizing resin of number average molecular mass ranging from 400 to 2000 g / mol and of transition temperature vitreous above 50 ° C and below 120 ° C which comprises, according to a mass fraction ranging from 70% to 100%, units resulting from the polymerization of a monocyclic or bicyclic unsaturated terpene.
• a plasticizing resin of number average molecular mass ranging from 400 to 2000 g / mol and of transition temperature vitreous above 50 ° C and below 120 ° C which comprises, according to a mass fraction ranging from 70% to 100%, units resulting from the polymerization of a monocyclic or bicyclic unsaturated terpene.
• said resin has a polymolecularity index of less than 2.
• said resin comprises said units resulting from the polymerization of a monocyclic or bicyclic unsaturated terpene according to a mass fraction ranging from 90% to 100%.
• said unsaturated terpene from which the resin is predominantly or wholly derived is a monocyclic unsaturated terpene, preferably a limonene (ie 1-methyl-4-isopropenyl cyclohexene) such as d-limonene (enantiomer dextrorotatory) or dipentene (racemic of the dextrorotatory and levorotatory enantiomers of limonene).
• a limonene ie 1-methyl-4-isopropenyl cyclohexene
• d-limonene enantiomer dextrorotatory
• dipentene racemic of the dextrorotatory and levorotatory enantiomers of limonene
• said resin consists of said units resulting from the homopolymerization of said monocyclic unsaturated terpene.
• a resin resulting entirely from the homopolymerization of d-limonene or dipentene preferably a resin of average molecular weight ranging from 550 g / mol to 650 g / mol and a glass transition temperature ranging from 60 ° C to 80 ° C.
• said rubber composition also comprises at least one plasticizing oil extracted from petroleum which is of the paraffinic type, aromatic or naphthenic, in an amount ranging from 0 phr to 25 phr and, preferably, ranging from 0 phr to 15 phr.
• composition according to the invention also comprises a reinforcing filler, in an amount which can vary from 50 to 150 phr.
• a silica having BET or CTAB specific surfaces which both range from 80 m 2 / g to 260 m 2 / g.
• highly dispersible silica means any silica having a very high ability to disaggregate and to disperse in an elastomer matrix, observable in known manner by electron or optical microscopy, on fine sections.
• preferential highly dispersible silicas mention may be made of the Ultrasil 7000 and Ultrasil 7005 silicas from the company Degussa, the Zeosil 1165MP, 1135MP and 1115MP silicas from the company Rhodia, the Hi-Sil EZ150G silica from the company PPG, Zeopol silicas 8715, 8745 and 8755 from the company Huber, treated precipitated silicas such as, for example, silicas "doped” with aluminum described in application EP-A-735 088.
• reinforcing inorganic filler is also understood to mean mixtures of various reinforcing inorganic fillers, in particular highly dispersible silicas as described above.
• reinforcing inorganic filler it is also possible to use, without limitation:
• said reinforcing filler comprises carbon black in a mass fraction ranging from 50% to 100%. All the carbon blacks conventionally used in tire casings and in particular in the treads of such casings, in particular blacks of the HAF, ISAF, SAF type, are suitable. Mention may be made, without limitation, of the blacks NI 15, N134, N234, N339, N347, N375.
• the rubber composition according to the invention additionally conventionally comprises a reinforcing inorganic filler / elastomer matrix (also called coupling agent) bonding agent, which has the function of ensuring a sufficient bonding (or coupling), of a chemical nature. and / or physical, between said inorganic charge and the matrix, while facilitating the dispersion of this inorganic charge within said matrix.
• a reinforcing inorganic filler / elastomer matrix also called coupling agent
• Coupled agent is understood to mean more specifically an agent capable of establishing a sufficient connection, of chemical and / or physical nature, between the filler considered and the elastomer, while facilitating the dispersion of this filler within the elastomer matrix.
• a coupling agent at least bifunctional, has for example as simplified general formula "Y-T-X", in which:
• - X represents a functional group (function "X") capable of physically and / or chemically bonding to the elastomer, for example by means of a sulfur atom;
• - T represents a group making it possible to connect Y and X.
• - n is an integer from 2 to 8 (preferably from 2 to 5);
• - A is a divalent hydrocarbon radical (preferably alkylene groups in
• R2 R2 R2 in which:
• radicals R i substituted or unsubstituted, identical or different from each other, represent a C ⁇ -C 18 alkyl group, C 5 -Ci8 cycloalkyl or C ⁇ -Ci aryl group, (preferably Ci-Ce alkyl groups . cyclohexyl or phenyl, in particular alkyl CC 4, more particularly methyl and / or ethyl).
• polysulphurized alkoxysilanes there may be mentioned more particularly polysulphides (in particular disulphides, trisulphides or tetrasulphides) of bis- (alkoxyl (C ⁇ -C 4 ) -alkyl (C ⁇ - C 4 ) silylalkyl (C ⁇ -C 4 )), for example bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl) polysulphides.
• TESPD bis (3-triethoxysilylpropyl) tetrasulfide, in short TESPT, of formula [(C 2 H 5 ⁇ ) 3Si (CH 2 ) 3 S 2 ] 2 or bis (triethoxysilylpropyl) disulfide, is used in particular abbreviated TESPD, of formula [(HsO ⁇ S ⁇ CHz ⁇ Slz.
• TESPD is marketed for example by the company Degussa under the names Si266 or Si75 (in the second case, in the form of a disulfide mixture (at 75% by weight) and of polysulphides), or by the company Witco under the name Silquest Al 589.
• TESPT is marketed for example by the company Degussa under the name Si69 (or X50S when it is supported at 50% by weight on carbon black), or by the company Osi Specialties under the name Silquest A1289 (in both cases, commercial mixture of polysulphides with an average value for n close to 4). Mention will also be made of monoalkoxysilanes tetrasulphides, such as tetrasulphide monoethoxydimethylsilylpropyl (in abbreviated MESPT), which are the subject of international patent application PCT / EP02 / 03774 in the name of the applicants.
• MESPT tetrasulphide monoethoxydimethylsilylpropyl
• the or at least one of the diene elastomers which can be used in the composition according to the invention may comprise one or more functional groups specifically active for coupling to said reinforcing filler.
• the functional groups, coupled or stars, which are known to a person skilled in the art for coupling to silica are suitable. Without limitation, agree:
• compositions in accordance with the invention can be prepared according to known methods of thermomechanical working of the constituents in one or more stages.
• a tire casing tread according to the invention is such that it comprises said rubber composition according to the invention.
• a tire casing according to the invention comprises this tread.
• Size exclusion chromatography or SEC allows physical separation of the macromolecules according to their size in the inflated state on columns filled with porous stationary phase. The macromolecules are separated by their hydrodynamic volume, the largest being eluted first. Without being an absolute method, the SEC makes it possible to apprehend the molecular mass distribution of low-weight diene elastomers. From commercial standard products of low molecular weight polystyrene (between 104 and 90,000 g / mol), the various average masses in number Mn and in weight Mp are determined and the polydispersity index Ip calculated. Each low weight elastomer sample is dissolved in tetrahydrofuran at a concentration of approximately 1 g / l.
• the volume injected with the solution of each elastomer sample is 100 ⁇ l.
• the detector is a "WATERS model 2410" differential refractometer and the operating software for the chromatographic data is the “WATERS MILLENIUM” system (version 3-2). Measurement of the glass transition temperatures of all the elastomers:
• Hysteretic losses (PH): measured in% by rebound at 60 ° C on the sixth shock, according to the following relationship: PH (%) 100 x (W 0 -W ⁇ ) / W ⁇ , with W 0 : energy supplied and Wi: energy returned.
• PH (%) 100 x (W 0 -W ⁇ ) / W ⁇ , with W 0 : energy supplied and Wi: energy returned.
• the grip of each tire casing tested was assessed by measuring the braking distances in "ABS” braking mode, both on dry and wet ground. More precisely, the braking distance in "ABS” mode was measured, on dry ground, passing from a speed of 70 km h to 20 km / h and, on wet ground (polished concrete ground with 2 mm height surface water), going from a speed of 40 km / h to 10 km / h.
• a “control” rubber composition T1 and two rubber compositions according to invention II and not in accordance with invention II ' were prepared, each intended to constitute a tread for a tire of the “touring” type. ".
• the following table 1 contains: the formulation of each of these compositions T1, II and II '; the properties of each composition T1, II and II 'in the unvulcanized and vulcanized state; the performance of tires, the respective treads of which consist of these compositions T1, II and II '.
• - S-SBR A is a copolymer of styrene and butadiene prepared in solution having: a rate of 1,2 chains of 58%, a rate of styrenic chains of 25%, a Mooney viscosity ML (l + 4) at 100 ° C equal to 54, an amount of oil equal to 37.5 pce, and a glass transition temperature Tg of -29 ° C.
• a T2 “control” rubber composition and two rubber compositions according to the invention 12 and not in accordance with the invention 12 ′ were prepared, each intended to constitute a tread of a tire envelope of the “touring” type. ".
• S-SBR A, BR A and BP1 are as defined in Example 1 and BP3 is a low-weight diene elastomer not in accordance with the invention because of its Tg less than -25 ° C, BP3 being a homopolymer of butadiene (rate of styrene sequences of 0%) exhibiting: a high rate of sequences 1.2 (equal to 71%); molecular masses Mn and Mw of 750 g / mol and 810 g / mol respectively, and a glass transition temperature Tg of -65 ° C.
• compositions 12, l'2 under a dynamic stress of high modulus are provided for substantially equal to the corresponding Tg of the “control” composition T2.
• Table 2 shows that the low-weight diene elastomers BP1 and BP3 respectively confer on compositions 12 and 12 ′ substantially the same mechanical and dynamic properties as those of the “control” composition T2.
• composition 12 only the incorporation of the elastomer BP1 according to the invention into composition 12 gives envelopes whose treads made of this composition a very improved resistance to wear compared to that of the “control” composition. »T2 comprising, as plasticizer, an aromatic oil in place of BPl, while practically retaining the adhesion and rolling resistance performance of the envelopes incorporating said composition T2 and by maintaining or improving the mechanical properties (Scott breaking) said composition T2.
• This is not the case with the incorporation of the BP3 elastomer into composition 12 ′.
• composition 12 does not include aromatic oil, unlike composition T2, which contributes to environmental protection.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Tires In General (AREA)

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• 2003
  • 2003-08-22 CN CNB038247909A patent/CN100567381C/zh not_active Expired - Fee Related
  • 2003-08-22 JP JP2004535141A patent/JP4642468B2/ja not_active Expired - Fee Related
  • 2003-08-22 AU AU2003266306A patent/AU2003266306A1/en not_active Abandoned
  • 2003-08-22 EP EP03794921A patent/EP1539878A1/fr not_active Withdrawn
  • 2003-08-22 WO PCT/EP2003/009333 patent/WO2004024813A1/fr active Application Filing
  • 2003-08-22 BR BR0306316-0A patent/BR0306316A/pt not_active Application Discontinuation
• 2005
  • 2005-03-10 US US11/076,285 patent/US7329704B2/en not_active Expired - Fee Related

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