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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
  • B60C1/0016—Compositions of the tread
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K13/00—Use of mixtures of ingredients not covered by one single of the preceding main groups, each of these compounds being essential
  • C08K13/02—Organic and inorganic ingredients
• • 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
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/05—Alcohols; Metal alcoholates
  • C08K5/053—Polyhydroxylic alcohols
• • 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
  • C08L3/00—Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L3/00—Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
  • C08L3/02—Starch; Degradation products thereof, e.g. dextrin

Definitions

• the European patent application EP0795581 describes tire rubber compositions comprising, in partial replacement of the carbon black, a starch plasticized with a polymer of vinyl alcohol and of ethylene. These compositions are described as allowing a decrease in rolling resistance over starch-free compositions and a stiffness adjustment.
• other European patent applications EP1074582, EP1293530, EP1312639 and EP1514900 also describe rubber compositions comprising a starch plasticized with a vinyl alcohol and ethylene polymer, in addition to usual fillers such as carbon black. and / or silica.
• plasticisers in the compositions may penalize the wear resistance of the tire by the addition of additional component, and therefore by the dilution of the elastomers that it causes, which makes these solutions less than optimal. .
• the invention therefore relates to a rubber composition based on at least one diene elastomer, a crosslinking system and a reinforcing filler characterized in that the composition also comprises a starch in a proportion of 10 to 50 phr (parts by weight). per hundred parts of elastomer) and an aqueous or water-soluble plasticizer in a proportion of 3 to 30 phr, said aqueous or water-soluble plasticizer being water, or a mixture of water and glycerol in which water is predominant in weight in the aqueous or water-soluble plasticizer.
• the invention relates to a composition as defined above in which the proportion of starch varies from 15 to 40 phr.
• the invention relates to a composition as defined above in which the proportion of aqueous or water-soluble plasticizer varies from 7 to 28 phr.
• the invention also relates to a composition as defined above, in which the starch consists of at least 10% amylose, more preferably at least 15% amylose, and so even more preferred at least 20% amylose.
• the invention relates to a composition as defined above, wherein the aqueous or water-soluble plasticizer is water.
• the invention further relates to calendered or shaped products comprising a rubber composition according to the invention; preferentially these products will be chosen from the sidewall, the carcass ply, the crown ply, the tread, the bead filler, the underlayer or other elastomer layers; and very preferably this product is the tread.
• the invention further relates to a tire comprising a product as described above.
• the tire tread designates the entire tread or a part thereof (including the underlayer), especially when it is composed of several layers, in contact with the ground.
• the rubber compositions according to the invention are based on the following constituents: at least one diene elastomer, a crosslinking system, a reinforcing filler, a starch and an aqueous or water-soluble plasticizer.
• iene elastomer can be understood more particularly to be used in the compositions according to the invention:
• 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, are particularly suitable.
• Suitable vinylaromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the "vinyl-toluene" commercial mixture, para-tertiarybutylstyrene, 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.
• silanol or polysiloxane functional groups having a silanol end as described, for example, in FR 2,740,778, US 6,013,718 and WO 2008/141702
• alkoxysilane groups as described for example in FR 2,765,882 or US 5,977,238,
• carboxylic groups as described for example in WO 01/92402 or US 6,815,473, WO 2004/096865 or US 2006/0089445).
• the high Tg elastomer is preferably selected from the group consisting of S-SBR, E-SBR, natural rubber, synthetic polyisoprenes (having a molar ratio (% molar) of C 1 -C 4 preferably greater than 95%), BIRs, SIRs, SBIRs, and mixtures of these elastomers.
• the low Tg elastomer preferably comprises butadiene units at a level (mol%) of at least 70%; it consists preferably of a polybutadiene (BR) having a content (mol%) of cis-1,4 chains greater than 90%.
• I-2 Reinforcing filler Any type of reinforcing filler known for its capacity to reinforce a rubber composition that can be used for the manufacture of tires, for example an organic filler such as carbon black, a reinforcing inorganic filler such as silica, or a blend of these two types of filler, including a cut of carbon black and silica.
• an organic filler such as carbon black
• a reinforcing inorganic filler such as silica
• a blend of these two types of filler including a cut of carbon black and silica.
• 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.
• silane polysulfides are more particularly the bis (mono, trisulfide or tetrasulfide) of bis (alkoxyl (CiC 4) - alkyl (CiC 4) silyl-alkyl (CiC 4)) as, for example, polysulfides of bis (3-trimethoxysilylpropyl) or bis (3-triethoxysilylpropyl).
• the content of coupling agent is preferably between 4 and 12 phr, more preferably between 5 and 10 phr.
• the composition according to the invention further comprises an additional non-aqueous and non-water-soluble plasticizing agent.
• this plasticizer is a solid hydrocarbon resin, a nonaqueous and non-water soluble liquid plasticizer, or a mixture of both.
• Non-aqueous and non-water-soluble phosphate plasticizers include those containing from 12 to 30 carbon atoms, for example trioctyl phosphate.
• 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, azela- sebacates, glycerol triesters and mixtures of these compounds.
• glycerol triesters preferably consisting predominantly (for more than 50%, more preferably more than 80% by weight) of an unsaturated fatty acid Ci 8 is 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.
• this plasticizer is a thermoplastic hydrocarbon resin whose Tg is greater than 0 ° C, preferably greater than 20 ° C.
• This resin is a solid at room temperature (23 ° C), as opposed to a liquid plasticizer such as an oil.
• Mn a number-average molecular weight (Mn) of between 400 and 2000 g / mol, more preferentially between 500 and 1500 g / mol;
• thermoplastic hydrocarbon plasticizing resin has all of the above preferred characteristics.
• 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. .
• hydrocarbon plasticizing resins there may be mentioned resins of homo- or copolymers of alphapinene, betapinene, dipentene or polylimonene.
• the level of plasticizing hydrocarbon resin is between 5 and 50 phr, preferably between 7 and 40 phr, more preferably between 10 and 35 phr.
• the content of plasticizing resin is between 5 and 20 phr, and more preferably between 5 and 15 phr.
• the compositions according to the invention can be used alone or in a blend (i.e., in a mixture) with any other rubber composition that can be used for the manufacture of tires.
• compositions are 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 (sometimes referred to as "non-phase" phase). at high temperature, up to a maximum temperature of between 110.degree. C. and 190.degree. C., preferably between 130.degree. C. and 180.degree.
• the first (non-productive) phase is preferably carried out in several thermomechanical steps.
• the elastomers are introduced into a suitable mixer such as a conventional internal mixer at a temperature of between 20 ° C. and 100 ° C. and preferably between 25 ° C. and 80 ° C. .
• a suitable mixer such as a conventional internal mixer
• the starch and the aqueous plasticizer or water-soluble are added at once or in parts (in two halves, three-thirds, four-quarters, or a third and then two-thirds for example) during a mixing ranging from 20 seconds to a few minutes.
• the total mixing time in this non-productive phase, is preferably between 2 and 10 minutes at a temperature of less than or equal to 180 ° C, and preferably less than or equal to 170 ° C.
• the invention also relates to a process for obtaining a rubber composition, which comprises a first thermomechanical kneading phase of the constituents of the composition, with the exception of the vulcanization system, characterized in that the composition also comprises starch in a proportion of 10 to 50 phr and an aqueous or water-soluble plasticizer in a proportion of 3 to 30 phr and in that the starch and the aqueous or water-soluble plasticizer are incorporated during the first mixing phase, said aqueous or water-soluble plasticizer being water, or a mixture of water and glycerol in which water is predominant by weight in the aqueous or water-soluble plasticizer.
• the invention relates to the process as defined above, in which the first mixing phase is carried out in several steps:
• the vulcanization (or cooking) is conducted in a known manner at a temperature generally between 130 ° C and 200 ° C, under pressure, for a sufficient time which can vary for example between 5 and 90 min depending in particular on the cooking temperature , the vulcanization system adopted, the kinetics of vulcanization of the composition in question or the size of the tire.
• a temperature generally between 130 ° C and 200 ° C, under pressure, for a sufficient time which can vary for example between 5 and 90 min depending in particular on the cooking temperature , the vulcanization system adopted, the kinetics of vulcanization of the composition in question or the size of the tire.
• the following examples illustrate the invention without limiting it.
• the dynamic properties G * and tan (5) max are measured on a viscoanalyzer (Metravib V A4000), according to ASTM D 5992 - 96.
• the response of a sample of vulcanized composition (cylindrical specimen of 2 mm diameter) is recorded. thickness and 78.5 mm 2 section), subjected to a sinusoidal stress in alternating single shear, at the frequency of 10 Hz, under normal temperature conditions according to ASTM D 1349-99. peak to peak deformation of 0.1 to 50% (forward cycle), then 50% to 1% (return cycle).
• the results exploited are the complex dynamic shear modulus (G * ) and the loss factor, tan (5).
• the maximum value of tan (5) observed (tan ( ⁇ ) max) is indicated.
• the dispersion is represented by its Z value, which is measured, after crosslinking, according to the method described by S. Otto et al. in Kautschuk Kunststoffe, 58 Canalgang, Nr 7-8 / 2005, in accordance with ISO 1345.
• compositions I-3 and I-4 comprising starch, a strong improvement of the rigidity revealed by the increase of the dynamic modulus G * at 10% of deformation at 23 ° C, while the hysteresis (Tan ( ⁇ ) max) remains stable or even slightly decreases.
• compositions 11-1, II-2, 11-3 and II-4 therefore have the same basic formula II, identical to the basic formula I described in Example I, with the exception of the choice of the copolymer of butadiene styrene specified in the previous paragraph.
• compositions 11-1, II-2, 11-3 and II-4 are given in Table 3 which follows.
• the volume fractions of charge are kept constant between the control (11-1) and the compositions II-2, 11-3 and I-4.
• Table 4 gives the properties measured after cooking at 150 ° C for 40 min.
• compositions II-2, 11-3 and II-4 comprising starch, a strong improvement of the rigidity revealed by the increase of the dynamic modulus G * to 10 % deformation at 23 ° C, while the hysteresis remains stable.
• water as a plasticizer or with a mixture of water and glycerin. It also appears in this example that the presence of plasticizer makes it possible to obtain a very improved dispersion of the fillers in the composition.
• This example is intended to compare different rubber properties a control composition not including starch (111-1) to compositions according to the invention, that is to say comprising a starch and an aqueous or water-soluble plasticizer (III-2 and III-3 ).
• the composition is based on a natural elastomer composed of NR natural rubber.
• compositions 111-1, III-2 and III-3 have the same basic formula III.
• This basic formulation III is as follows: NR (1 1) 100
• the composition 111-1 is manufactured with an introduction of all the constituents on an internal mixer.
• the vulcanizing agents sulfur and accelerator
• the vulcanizing agents are introduced on an external mixer at low temperature (the constituent rolls of the mixer being at about 50 ° C.).
• compositions III-2 and III-3 are manufactured according to the process of the invention, with introduction of the elastomer during a first step of the first mixing phase on an internal mixer.
• the starch and the aqueous or water-soluble plasticizer are introduced in two halves during the next two successive stages of this first phase on the internal mixer.
• the other constituents are then introduced.
• the vulcanization system is then introduced on an external mixer, during the second phase of the process.
• Table 6 gives the properties measured after baking at 150 ° C. for 15 minutes.
• compositions III-2 and III-3 comprising starch, a strong improvement of the rigidity revealed by the increase of the dynamic modulus G * at 10% deformation at 23 ° C, while the hysteresis decreases very slightly.

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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)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

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• 2010
  • 2010-05-04 FR FR1053437A patent/FR2959744B1/fr active Active
• 2011
  • 2011-05-02 WO PCT/EP2011/056942 patent/WO2011138267A1/fr active Application Filing
  • 2011-05-02 EP EP11716584A patent/EP2566915A1/de not_active Withdrawn
  • 2011-05-02 JP JP2013508450A patent/JP5745618B2/ja not_active Expired - Fee Related
  • 2011-05-02 US US13/641,564 patent/US20130231417A1/en not_active Abandoned

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