Classifications

• • 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
• • 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
  • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
  • B60C15/06—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
  • C08J5/10—Reinforcing macromolecular compounds with loose or coherent fibrous material characterised by the additives used in the polymer mixture
• • 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
  • C08K5/0091—Complexes with metal-heteroatom-bonds
• • 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
  • C08K5/09—Carboxylic acids; Metal salts thereof; Anhydrides thereof
  • C08K5/098—Metal salts of carboxylic acids
• • 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
  • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
  • B60C9/0007—Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal
  • B60C2009/0021—Coating rubbers for steel cords
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
  • Y10T428/12556—Organic component
  • Y10T428/12562—Elastomer

Definitions

• the present invention relates to rubber compositions and to metal / rubber composites, in particular to compositions and composites which can be used for the manufacture of ground connection systems for motor vehicles, in particular tires.
• Metal / rubber composites in particular for tires, are well known, they generally consist of a diene rubber matrix, crosslinkable with sulfur, comprising metallic reinforcing elements (or “reinforcements"), generally in the form of a wire (s). ) or wire assemblies.
• these composites must in known manner satisfy a large number of technical criteria, sometimes contradictory, such as uniformity, flexibility, endurance in flexion and compression, tensile, wear and corrosion resistance, and maintain these performances at a very high level as long as possible.
• the traditional method for connecting rubber compositions to carbon steel consists in coating the surface of the steel with brass (copper-zinc alloy), the connection between the steel and the rubber matrix being provided by sulfurization of the brass during vulcanization; in order to improve adhesion, organic salts or cobalt complexes are also frequently used in said rubber compositions as adhesion-promoting additives (see for example the patent documents FR-A- 2,501,700 or US-A-4,549,594; US-A-4,933,385; US-A-5,624,764).
• a first object of the invention is a rubber composition which can be used for the manufacture of a metal / rubber composite and capable of adhering to a metal reinforcement, comprising at least one diene elastomer, a reinforcing filler, a system of crosslinking and an adhesion promoter, characterized in that said adhesion promoter comprises a lanthanide compound.
• the invention also relates to the use as an adhesion promoter with respect to a metal reinforcement, in a diene rubber composition, of such a lanthanide compound.
• the invention also relates in itself to a metal / rubber adhesion promoter system, characterized in that it comprises in combination a lanthanide compound and a cobalt compound.
• the subject of the invention is also a metal / rubber composite comprising a diene rubber composition according to the invention and at least one metallic reinforcement adhering to said rubber composition.
• This metal / rubber composite is characterized by an improved metal-rubber adhesive interphase, offering a level of adhesion at least as good in the initial state (directly after curing), compared to the known prior solutions, with in addition markedly improved performance. after thermal type aging, in particular under humidity conditions.
• the invention also relates to the use of such a composite for the manufacture or reinforcement of ground connection systems of motor vehicles, such as a tire, internal safety support for a tire, wheel, rubber spring, elastomeric articulation, other suspension and anti-vibration element, or even semi-finished rubber products intended for such ground connection systems.
• motor vehicles such as a tire, internal safety support for a tire, wheel, rubber spring, elastomeric articulation, other suspension and anti-vibration element, or even semi-finished rubber products intended for such ground connection systems.
• the composite according to the invention is particularly intended for reinforcements of reinforcement of the crown, of the carcass or of the bead zone of tires intended to equip passenger-type motor vehicles, SUVs ("Sport Utility Vehicles"), two wheels (in particular motorcycles), airplanes, such as industrial vehicles chosen from vans, "Heavy vehicles” - that is to say metro, bus, road transport vehicles (trucks, tractors, trailers), off-road vehicles such as agricultural or civil engineering vehicles, other transport or handling vehicles.
• SUVs Sport Utility Vehicles
• two wheels in particular motorcycles
• airplanes such as industrial vehicles chosen from vans, "Heavy vehicles” - that is to say metro, bus, road transport vehicles (trucks, tractors, trailers), off-road vehicles such as agricultural or civil engineering vehicles, other transport or handling vehicles.
• the invention also relates to the ground bonding systems and the semi-finished rubber products themselves, when they comprise a composite according to the invention.
• the invention shows in particular all its interest in the carcass reinforcement of tires for heavy goods vehicles which we expect today, thanks to the technical progress of retreading, that they are able to endure more than a million kilometers. , as well as in the crown reinforcement of tires intended both for passenger vehicles and for industrial vehicles. The longevity of tires can thus be significantly improved, in particular that of tires subjected to particularly severe running conditions, in particular in a humid and corrosive atmosphere.
• the quality of the connection between the metal reinforcement and the rubber matrix is assessed by a test in which the force, called tear-out force, necessary to extract the metal reinforcement from the rubber matrix is measured in the vulcanized state.
• the metal / rubber composite used in this test is a rubber composition block, consisting of two plates of dimension 300 mm by 150 mm (millimeters) and thickness 3.5 mm, applied one on the other before the cooking; the thickness of the resulting block is then 7 mm. It is during the making of this block that the reinforcements, for example twelve in number, are trapped between the two green plates; only a determined reinforcement length, for example 12.5 mm, is left free to come into contact with the rubber composition to which this reinforcement length will bond during baking; the rest of the length of the reinforcements is isolated from the rubber composition (for example using a plastic or metallic film) to prevent any adhesion outside the determined contact zone. Each reinforcement passes through the rubber block right through, at least one of its free ends being kept of sufficient length (at least 5 cm, for example between 5 and 10 cm) to allow subsequent traction of the reinforcement.
• the block comprising the twelve reinforcements is then placed in a suitable mold and then baked, unless otherwise indicated, for 40 minutes at 150 ° C, under a pressure of about 11 bars.
• the rubber blocks are placed in an oven at a temperature of 135 ° C., for 16 hours;
• the rubber blocks are placed in an oven at a temperature of 105 ° C., for 16 hours and under a relative humidity of 100%.
• the block is cut into test pieces serving as samples, each containing a reinforcement which is pulled out of the rubber block, using a traction machine; the traction speed is 50 mm / min; adhesion is thus characterized by the force necessary to tear the reinforcement out of the test piece, at a temperature of 20 ° C; the breakout force (denoted Fa) represents the average of the 12 measurements corresponding to the 12 reinforcements of the composite.
• the metal / rubber composite of the invention which can be used for the manufacture or reinforcement of ground connection systems of motor vehicles such as for example tires, comprises at least one composition or matrix of rubber, itself the subject of the invention, and a metal reinforcement to which it is capable of adhering, both described in detail below.
• composition of the invention is an elastomeric composition based (i.e., comprising the mixture or the reaction product) of at least one diene elastomer, a reinforcing filler, a crosslinking system and an adhesion promoter.
• adhesion promoter consists, in whole or in part, of a lanthanide compound.
• iene elastomer or indistinctly rubber is meant in known manner an elastomer derived at least in part (ie, a homopolymer or a copolymer) from diene monomers (monomers carrying two carbon-carbon double bonds, conjugated or not) .
• Diene elastomers can be classified in a known manner into two categories: those called “essentially unsaturated” and those called “essentially saturated”.
• the term “essentially unsaturated” diene elastomer is understood here to mean a diene elastomer derived at least in part from conjugated diene monomers, having a rate of units or units of diene origin (conjugated dienes) which is greater than 15% (% in moles).
• conjugated diene monomers having a rate of units or units of diene origin (conjugated dienes) which is greater than 15% (% in moles).
• diene elastomers such as butyl rubbers or copolymers of dienes and alpha-olefins of the EPDM type do not enter into the preceding definition and can be qualified in particular as "essentially saturated diene elastomers”.
• the diene elastomer is chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), the different butadiene copolymers, the different isoprene copolymers, and the mixtures of these elastomers.
• Such copolymers are more preferably chosen from the group consisting of butadiene-styrene copolymers (SBR), whether the latter are prepared by emulsion polymerization (ESBR) as in solution (S SBR), isoprene-butadiene copolymers ( BIR), isoprene-styrene copolymers (SIR) and isoprene-butadiene-styrene copolymers (SBIR).
• SBR butadiene-styrene copolymers
• BIR isoprene-butadiene copolymers
• SIR isoprene-styrene copolymers
• SBIR isoprene-butadiene-styrene copolymers
• polybutadienes in particular those having a content of units -1,2 between 4% and 80% or those having a content of cis-1,4 greater than 80% are suitable.
• the synthetic polyisoprenes the cis-1,4-polyisoprenes are particularly suitable, preferably those having a rate of cis-1,4 bonds greater than 90%.
• the butadiene or isoprene copolymers we mean in particular the copolymers obtained by copolymerization of at least one of these two monomers with im or more vinyl-aromatic compounds having from 8 to 20 carbon atoms.
• Suitable vinyl-aromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the commercial "vinyl-toluene" mixture, para-tertiobutylstyrene, methoxystyrenes, chlorostyrenes, vinyl mesitylene, divinylbenzene. , vinylnaphthalene.
• the copolymers may contain between 99% and 20% by weight of diene units and between 1% and 80% by weight of vinyl-aromatic units.
• the composites in accordance with the invention are preferably intended for tires, in particular for the carcass reinforcement of tires for industrial vehicles such as vans or HGVs, as well as for the crown reinforcement of tires intended for both passenger vehicles and industrial vehicles.
• At least one isoprene elastomer is used, that is to say, in known manner, an isoprene homopolymer or copolymer, in other words a diene elastomer chosen from the group consisting of rubber. natural (NR), synthetic polyisoprenes (IR), the various isoprene copolymers and mixtures of these elastomers.
• the isoprene elastomer is preferably natural rubber, or a synthetic polyisoprene of the cis-1,4 type preferably having a rate of cis-1,4 bonds greater than 90%, more preferably still greater than 98%.
• the rubber compositions can contain diene elastomers other than isoprene, in particular SBR and / or BR elastomers as mentioned above, whether the isoprene elastomer is present in the majority or not all of the diene elastomers used.
• an SBR copolymer having a Tg glass transition temperature, measured according to ASTM D3418
• Tg glass transition temperature, measured according to ASTM D3418
• S SBR emulsion
• S SBR solution
• an SSBR is then used.
• Said SBR may also be associated with a BR preferably having more than 90%> of cis-1,4 bonds, said BR having a Tg preferably between -110 ° C and -50 ° C.
• the rubber matrix may contain one or more diene elastomers, the latter or these being able to be used in combination with any type of synthetic elastomer other than diene, or even with polymers other than elastomers, for example polymers thermoplastics.
• reinforcing filler known for its capacity to reinforce a rubber composition which can be used for the manufacture of tires can be used, for example a organic filler such as carbon black, or also a reinforcing inorganic filler such as silica with which a coupling agent is associated in known manner.
• Carbon black is preferably used.
• all carbon blacks are suitable, in particular blacks of the HAF, ISAF, SAF type conventionally used in tires (so-called pneumatic grade blacks).
• the reinforcing carbon blacks of the 100, 200 or 300 series such as, for example, the blacks NI 15, NI 34, N234, N326, N330, N339, N347, N375, or else , depending on the intended applications, the blacks of higher series (for example N660, N683, N772).
• inorganic filler should be understood here any inorganic or mineral filler, whatever its color and its origin (natural or synthetic), also called “white” filler or sometimes “clear” filler as opposed to carbon black , capable of reinforcing on its own, without other means than an intermediate coupling agent, a rubber composition intended for the manufacture of tires, in other words capable of replacing, in its reinforcement function, a conventional carbon black pneumatic grade; such a charge is generally characterized, in a known manner, by the presence of hydroxyl groups (-OH) on its surface.
• -OH hydroxyl groups
• mineral fillers of the siliceous type in particular silica (Si (2), or of the aluminous type, in particular of alumina (AI2O3) are suitable.
• the silica used can be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenic silica having a BET surface as well as a CTAB specific surface, both less than 450 m 2 / g, preferably from 30 to 400 m 2 / g.
• HDS highly dispersible precipitated silicas
• reinforcing aluminas examples include "Baikalox”"A125” or “CR125” aluminas from the company Baikowski, “APA-100RDX” from Condea, “Aluminoxid C” from Degussa or “AKP-G015" from Sumito o Chemicals.
• an at least bifunctional coupling agent intended to ensure a sufficient connection, of chemical and / or physical nature, between the inorganic filler will be used in a well known manner. (surface of its particles) and the diene elastomer, in particular organosilanes or bifunctional polyorganosiloxanes.
• the rate of total reinforcing filler is between 20 and 200 phr, more preferably between 30 and 150 phr, the optimum being in known manner different according to the intended applications.
• the crosslinking system is preferably a vulcanization system, that is to say a system based on sulfur (or a sulfur donor agent) and on a primary vulcanization accelerator.
• a vulcanization system that is to say a system based on sulfur (or a sulfur donor agent) and on a primary vulcanization accelerator.
• various secondary accelerators or known vulcanization activators such as zinc oxide , stearic acid or equivalent compounds, guanidine derivatives (in particular diphenylguanidine).
• Sulfur is used at a preferential rate of between 0.5 and 10 phr, more preferably between 1 and 8 phr, in particular between 1 and 6 phr when the composition of the invention is intended, according to a preferential method of invention, to constitute an internal "rubber" (or rubber composition) of a tire.
• the primary vulcanization accelerator is used at a preferential rate of between 0.5 and 10 phr, more preferably of between 0.5 and 5.0 phr.
• accelerators of the thiazole type and their derivatives, accelerators of the thiuram, zinc dithiocarbamate type can be used as accelerator.
• These primary accelerators are more preferably chosen from the group consisting of 2-mercaptobenzothiazyl disulfide (abbreviated to "MBTS”), N-cyclohexyl-2-benzothiazyl sulfenamide (abbreviated to “CBS”), N, N-dicyclohexyl-2-benzothiazyle sulfenamide (abbreviated “DCBS”), N-ter-butyl-2-benzothiazyle sulfenamide (abbreviated “TBBS”), N-ter-butyl-2-benzothiazyl sulfenimide (abbreviated "TBSI”) and mixtures of these compounds .
• MBTS 2-mercaptobenzothiazyl disulfide
• CBS N-cyclohexyl-2-benzothiazyl sulfenamide
• DCBS N-dicyclohexyl-2-benzothiazyle sulfenamide
• lanthanide is reserved for metals, called “rare earths”, whose atomic number varies from 57 (lanthanum) to 71 (lutetium).
• the lanthanide is chosen from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, erbium and mixtures of these rare earths. More preferably, cerium or neodymium is used, in particular neodymium.
• the lanthanide compound can be of the inorganic or organic type.
• inorganic compounds mention may in particular be made of phosphorus derivatives such as, for example, lanthanide phosphates, in particular those of neodymium.
• an organic lanthanide or “organolanthanide” compound is used, chosen in particular from the group consisting of organic salts and derivatives, in particular alcoholates or carboxylates, as well as lanthanide complexes.
• the ligands (or ligands) of such complexes contain from 1 to 20 carbon atoms, they are generally selected from the group consisting of o-hydroxyaldehydes, o-hydroxyphenones, hydroxyesters, ⁇ -diketones, orthodihydric phenols, alkylene glycols , monocarboxylic acids, dicarboxylic acids and alkylated derivatives of dicarboxylic acids.
• Such organolanthanides are preferably chosen from the group consisting of abietates, acetates, diethylacetates, acetonates, acetylacetonates, benzoates, butanolates, butyrates, cyclohexane-carboxylates, decanolates, ethylhexanoates, ethylhexanolates, formateates, neatheenates, neatheodenates, neatheenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neatheodenates, neathe
• abietates acetates, acetylacetonates, benzoates, butyrates, formiates, linoleates, maleates, oleates, propionates, naphthenates, resinates, stearates, and mixtures (salts, complexes, or others mixed derivatives) of such compounds.
• Acetylacetonates and naphthenates are the preferred organolanthanides in the majority of cases, more particularly acetylacetonates.
• the compound level of lanthanide is preferably between 0.1 and 10 phr. Below 0.1 phr, the targeted technical effect is likely to be insufficient, while beyond 10 phr, there is the risk of an increase in costs and the risk of degrading certain mechanical properties of the compositions, the initial state as after aging. For these various reasons, said level of lanthanide compound is more preferably between 0.2 and 5 phr, even more preferably between 0.5 and 2.5 phr.
• lanthanide compounds for example neodymium salts such as carboxylates
• catalysts for the polymerization of polymers or elastomers such as dienes see by way of examples US-A-3 803 053, US-A-5 484 897, US-A-5 858 903, US-A-5 914 377, US-B-6 800 705).
• Other constituents for example neodymium salts such as carboxylates
• the rubber matrices of the composites in accordance with the invention also comprise all or part of the additives usually used in rubber compositions intended for the manufacture of systems for bonding to the ground of motor vehicles, in particular tires, such as for example agents anti-aging, antioxidants, plasticizers or extension oils, whether these are of aromatic or non-aromatic nature, in particular very weak or non-aromatic oils (eg, naphthenic or paraffinic oils, MES or TDAE oils), agents facilitating the use of the compositions in the raw state, a crosslinking system based either on sulfur or on sulfur and / or peroxide donors, accelerators, activators or retarders of vulcanization, anti-reversion agents such as for example sodium hexathiosulfonate or N, N'-m-phenylene-biscitraconimide, methyl acceptors and donors ene (for example resorcinol, HMT or H3M) or other reinforcing resins, bismaleimides, other systems promoting adh
• a particular embodiment consists in using a bismaleimide compound.
• This type of compound which can be used without hardening agent, has a kinetics of curing well suited to that of tires, it is capable of activating the kinetics of adhesion and of further improving, in the composites in accordance with the invention, the endurance in wet aging conditions of the adhesive interphases.
• R is a hydrocarbon, aromatic or aliphatic, cyclic or acyclic radical, substituted or unsubstituted, such a radical possibly comprising a heteroatom chosen from O, N and S; this radical R preferably contains from 2 to 24 carbon atoms.
• a bismaleimide chosen from the group consisting of N, N'-ethylene-bismaleimides, N, N'-hexamethylene-bismaleimides, N, N '- (m-phenylene) is used.
• Such bismaleimides are well known to those skilled in the art.
• a reinforcing resin or a bismaleimide is used, it is present in the composite of the invention at a preferential rate of between 0.1 and 20%, more preferably between 1 and 8% by weight of rubber composition.
• a preferential rate of between 0.1 and 20%, more preferably between 1 and 8% by weight of rubber composition.
• the composition comprises, in association with the lanthanide compound, at least one cobalt compound according to a preferential level of between 0.1 and 10 phr. It has been found that a certain synergy can exist between the two compounds, resulting in particular in a greater improvement in the adhesive performance under thermal and wet aging conditions. For the same reasons as those indicated above for the lanthanide compound, the level of cobalt compound is then more preferably between 0.2 and 5 phr, even more preferably between 0.5 and 2.5 phr.
• the cobalt compound is preferably an organic cobalt compound, chosen more preferentially from the group consisting of abietates, acetates, acetylacetonates, benzoates, butyrates, formiates, linoleates, maleates, oleates, propionates, naphthenates, resinates, stearates, and mixtures (that is to say salts, complexes, or other mixed derivatives) of such compounds, in particular among the abietates, acetylacetonates, naphthenates, resinates and mixtures of such compounds. Acetylacetonates and naphthenates are preferred in the majority of cases.
• compositions are made in suitable mixers, using two phases of. successive preparations well known to those skilled in the art: a first working phase or thermomechanical kneading (so-called “non-productive” phase) at high temperature, up to a maximum temperature of between 110 ° C. and 190 ° C., preferably between 130 ° C and 180 ° C, followed by a second mechanical working phase (so-called “productive” phase) to a lower temperature, typically below 110 ° C, finishing phase during which is incorporated the crosslinking system.
• a first working phase or thermomechanical kneading at high temperature, up to a maximum temperature of between 110 ° C. and 190 ° C., preferably between 130 ° C and 180 ° C
• a second mechanical working phase so-called “productive” phase
• the non-productive phase is carried out in a single thermomechanical step of a few minutes (for example between 2 and 10 min) during which, in a suitable mixer such as a usual internal mixer, all the necessary basic constituents and other additives, with the exception of the crosslinking or vulcanization system.
• a suitable mixer such as a usual internal mixer
• all the necessary basic constituents and other additives with the exception of the crosslinking or vulcanization system.
• the vulcanization system is then incorporated into an external mixer such as a cylinder mixer, maintained at low temperature (for example between 30 ° C. and 100 ° C.).
• the whole is then mixed (productive phase) for a few minutes (for example between 5 and 15 min).
• the final composition thus obtained can then be calendered, for example in the form of a sheet, a plate or even extruded, for example to form a rubber profile used for the manufacture of a composite or of a semi-finished product.
• -finished such as for example plies, strips, under-layers, other rubber blocks reinforced with metal reinforcements, intended to form for example a part of the structure of a tire.
• Vulcanization (or baking) can then be carried out in a known manner at a temperature generally between 130 ° C and 200 ° C, preferably under pressure, for a sufficient time which can vary for example between 5 and 90 min depending in particular on the baking temperature, the vulcanization system adopted and the vulcanization kinetics of the composition considered.
• the invention relates to rubber compositions and composites both in the so-called “raw” state (i.e. before curing) and in the so-called “cooked” or vulcanized state (i.e. after vulcanization).
• metal reinforcement should be understood any reinforcing element capable of reinforcing the rubber matrix, whether entirely metallic or not, of which at least the surface or external part, intended to come into contact with the rubber, is made of metal.
• This reinforcement can be in different forms, preferably in the form of a unitary wire (monofilament), a film (for example a strip or a ribbon) or an assembly of wires, whether these wires are twisted together. (for example, in the form of a cable) or essentially parallel to one another (for example in the form of a bundle of wires, a continuous fiber or even a set of short fibers).
• this reinforcement is more preferably in the form of a unitary wire or an assembly of wires, for example a cable or a strand manufactured with devices and methods wiring or stranding known to those skilled in the art, which are not described here for the simplicity of the description.
• the metal, or surface metal if necessary, of the metal reinforcement is preferably chosen from Fe, Cu, Zn, Al, Sn, Ni, Co, Cr, Mn, the oxides, hydroxides and alloys of these elements, more preferably from Fe, Cu, Zn, Al, Sn, their oxides, hydroxides and alloys.
• Use is preferably made of a steel reinforcement, in particular of perlitic (or ferritoperlitic) carbon steel known in a known manner as "carbon steel", or also of stainless steel as described for example in patent applications EP-A -648 891 or WO98 / 41682.
• a steel reinforcement in particular of perlitic (or ferritoperlitic) carbon steel known in a known manner as "carbon steel”, or also of stainless steel as described for example in patent applications EP-A -648 891 or WO98 / 41682.
• carbon steel When carbon steel is used, its carbon content is preferably between 0.1% and 1.2%>, especially between 0.5% and 1.1%) (%> by weight of steel ); it is more preferably between 0.6% and 1.0%, such a content representing a good compromise between the mechanical properties required for the tire and the feasibility of the cords.
• the metal or steel used can be used as it is (so-called "light steel") or be itself coated with an additional metal layer, for example improving the processing properties of the metal reinforcement and / or its constituent elements, or the use properties of the reinforcement and / or the composite themselves.
• the steel used in particular when it is a carbon steel, is covered with an additional layer of metal chosen from aluminum, zinc, copper and binary alloys or ternary of these metals.
• aluminum alloys preference is given to those chosen from the binary alloys Al-Mg, Al-Cu, Al- ⁇ i, Al-Zn and the ternary alloys of Al and two of the elements Mg, Cu, Ni, Zn, more particularly an Al-Zn alloy.
• the zinc alloys those chosen from the binary alloys Zn-Cu, Zn-Al, Zn-Mn, Zn-Co, Zn-Mo, Zn-Fe, Zn-Ni, Zn-Sn and the alloys are preferably used.
• ternaries of Zn and two of the elements for example Zn-Cu-Ni or also Zn-Cu-Co), more particularly a Zn-Cu (brass) alloy or a Zn-Al alloy as mentioned above.
• the preferred binary alloys are those of Cu-Zn (aforementioned brass) and Cu-Sn (bronze).
• any deposition process may be used which is capable of applying, continuously or in discontinuous, a metallic coating on a metallic substrate.
• the additional metal layer will preferably be deposited on the wires, and not on the final cable.
• the deposition will advantageously be carried out on a wire of so-called "intermediate" diameter, for example of the order of a millimeter, at the outlet of the last heat treatment (patenting) preceding the step wet final drawing to obtain the fine wire having the final target diameter.
• the reinforcements used are preferably assemblies (strands or cables) of fine wires made of carbon steel or stainless steel having: a resistance in tension greater than 2000 MPa, more preferably greater than 2500 MPa, in particular greater than 3000 MPa; a person skilled in the art knows how to manufacture fine wires having such a resistance, in particular by adjusting the composition of the steel and the final work hardening rates of these wires; for a good compromise between resistance / flexural strength / feasibility, a diameter ⁇ of between 0.10 and 0.40 mm, more preferably between 0.10 and 0.30 mm approximately when the composite is intended to reinforce a carcass reinforcement, between about 0.20 and 0.40 mm when the composite is intended to reinforce a crown reinforcement.
• the reinforcements may be in particular in the form of bead wires made up of carbon steel or stainless steel wires, unitary or assembled, these wires having: traction greater than 1500 MPa, more preferably greater than 2000 MPa; a diameter ⁇ (or a characteristic dimension, if it is a wire other than cylindrical) of between 0.5 and 3 mm, more preferably between 0.8 and 2.2 mm. fl-3.
• bead wires made up of carbon steel or stainless steel wires, unitary or assembled, these wires having: traction greater than 1500 MPa, more preferably greater than 2000 MPa; a diameter ⁇ (or a characteristic dimension, if it is a wire other than cylindrical) of between 0.5 and 3 mm, more preferably between 0.8 and 2.2 mm. fl-3.
• the rubber composition of the invention and the metal reinforcement previously described can be used for the manufacture of a metal / rubber composite which constitutes another object of the invention, a composite in which adhesion between the metal and the rubber is ensured through the use in said composition of the lanthanide compound.
• This composite can be in various forms, for example in the form of a sheet, a strip, a strip or a block of rubber in which the metal reinforcement is incorporated, or else a coating of rubber covering the metal reinforcement, the latter being in direct contact with the rubber composition.
• the final adhesion between the metal and the rubber composition can be obtained at the end of the firing of the finished article comprising the composite; preferably, this cooking is carried out under pressure.
• the composites according to the invention are preferably intended for tires, in particular for radial tires to form all or part of the crown reinforcement, of the carcass reinforcement or the reinforcement of the bead zone of such tires.
• the appended figure very schematically represents a radial section of a tire 1 with a radial carcass reinforcement according to the invention, intended for a HGV vehicle as for a passenger vehicle in this general representation.
• This tire 1 has a crown 2, two sidewalls 3, two beads 4, a carcass reinforcement 7 extending from one bead to the other.
• the crown 2 surmounted by a tread (not shown in this diagrammatic figure, for simplicity), is in a manner known per se reinforced by a crown reinforcement 6 consisting for example of at least two overlapped crossed crown plies (plies so-called "working top"), possibly covered with at least one protective ply or a zero-degree hoop top ply.
• the carcass reinforcement 7 is wound around the two rods 5 in each bead 4, the reversal 8 of this reinforcement 7 being for example placed towards the outside of the tire 1 which is here shown mounted on its rim 9.
• the reinforcement of carcass 7 consists of at least one ply reinforced by so-called “radial” cables, that is to say that these cables are arranged practically parallel to one another and extend from one bead to the other of so as to form an angle between 80 ° and 90 ° with the median circumferential plane (plane perpendicular to the axis of rotation of the tire which is located midway between the two beads 4 and passes through the middle of the crown reinforcement 6).
• this tire 1 also comprises, in a known manner, a layer of inner rubber or elastomer (commonly called “inner rubber”) which defines the radially internal face of the tire and which is intended to protect the carcass ply from the diffusion of air from the interior of the tire.
• a tire for a heavy vehicle may further comprise an intermediate elastomeric reinforcing layer which is situated between the carcass ply and the inner layer, intended to reinforce the inner layer and, by Consequently, the carcass ply, also intended to partially relocate the stresses undergone by the carcass reinforcement.
• the tire according to the invention has the essential characteristic of comprising in its structure at least one metal / rubber composite according to the invention, this composite possibly being, for example, part of the bou ⁇ elet zone 4 comprising the bead wire 5, a crossed crown ply or a protective ply of the crown reinforcement 6, a ply forming all or part of the carcass reinforcement 7.
• the composite of the invention is advantageously usable in the crown reinforcement of all types of tires, for example for passenger vehicles, vans or heavy goods vehicles.
• the rubber composition of the invention has, in the vulcanized state (ie, after curing), an E10 module which is greater than 4 MPa, more preferably between 6 and 20 MPa, for example between 6 and 15 MPa.
• the composite of the invention can have an equally advantageous use in a carcass reinforcement of a tire for an industrial vehicle such as Heavy goods vehicle.
• the rubber composition of the invention has, in the vulcanized state, a module E10 which is less than 9 MPa, more preferably between 4 and 9 MPa.
• a diene elastomer (or mixture of diene elastomers) is introduced into an internal mixer, filled to 70% and whose initial tank temperature is approximately 60 ° C. , if applicable), the reinforcing filler and the various other ingredients with the exception of the vulcanization system.
• a thermomechanical work non-productive phase
• total duration of mixing equal for example to about 7 min
• the mixture thus obtained is recovered, it is cooled and then the vulcanization system (sulfur and sulfenamide accelerator) is added on an external mixer (homo-finisher) at 30 ° C, mixing the whole (productive phase) for example for 3 to 10 minutes.
• vulcanization system sulfur and sulfenamide accelerator
• compositions thus obtained are then either extradited in the form of plates (thickness of 2 to 3 mm) for the measurement of their physical or mechanical properties, or calendered to produce a metallic cabled fabric constituting a part of the crown reinforcement. of a tire for passenger vehicle.
• compositions have been reported in Tables 1 and 2 appended. They essentially comprise, in addition to the elastomer and the reinforcing filler, a paraffinic oil, an antioxidant, zinc oxide, stearic acid, sulfur and a sulfenamide accelerator, for some of them ( Ml to M-4) a reinforcing resin (phenolic resin plus methylene donor), finally a metal / rubber adhesion promoter comprising either a cobalt compound alone for the control compositions (Ml and M-5), or a compound of cobalt and a lanthanide compound for the compositions according to the invention (M-2 to M-4, M-6 to M-8).
• Cables made up of fine carbon steel wires, covered with brass, are used, suitable for reinforcing crown reinforcement of passenger tires.
• the fine carbon steel wires are prepared starting, for example, from machine wires (diameter 5 to 6 mm) which are first worked cold, by rolling and / or drawing, up to an intermediate diameter close to 1 mm. , or even starting directly from intermediate commercial wires whose diameter is close to 1 mm.
• the steel used is a known carbon steel, for example of the USA AISI 1069 type, the carbon content of which is approximately 0.8% o, comprising approximately 0.5% of manganese, the remainder consisting of iron and impurities usual unavoidables linked to the steel manufacturing process (for example, silicon contents: 0.25%; phosphorus: 0.01%; sulfur: 0.01%; chromium: 0.11%; nickel: 0.03 %; copper: 0.01%; aluminum: 0.005%; nitrogen: 0.003%>).
• Intermediate diameter wires then undergo a degreasing and / or pickling treatment, before their further processing.
• a so-called “final” hardening is carried out on each wire, by cold drawing in a humid environment with a drawing lubricant which is, for example, in the form of an aqueous emulsion or dispersion.
• Each carbon steel wire is coated with a layer of brass (64%> copper and 36% zinc).
• the brass coating has a very small thickness, significantly less than a micrometer, which is equivalent to about 0.35 to 0.40 g of brass per 100 g of wire.
• 8 carbon steel / rubber composites are prepared by calendering, denoted respectively C-1 to C-8, having the form of rubber blocks intended for adhesion test described in paragraph 1-2 above.
• the composite C-1 is the control comprising a conventional rubber matrix also comprising a reinforcing resin and a cobalt compound as adhesion promoter (matrix M-1).
• Composites C-2 to C-4, all three in accordance with the invention, are distinguished only by the additional presence of an organolanthanide (neodymium, cerium or samarium) in their rubber matrix (M-2 to M-4) .
• the composites according to the invention all have an initial adhesion (tearing force Fa) which is slightly greater than that of the control (C-1) characterized however by a starting adhesion level which is very high (of the order of 30 daN) for the composite considered.
• organolanthanide compound therefore makes it possible to slightly improve the initial adhesion and to considerably increase the adhesive performance after thermal aging.
• the adhesive performances of the composites C-5 to C-8 are compared in this test, this time subjected to the conditions of "thermal and wet aging".
• the composite C-5 is the control comprising a conventional rubber matrix containing in particular a cobalt compound as an adhesion promoter and moreover devoid of reinforcing resin (matrix M-5).
• Matrix M-5 a cobalt compound as an adhesion promoter and moreover devoid of reinforcing resin
• Composites C-6 to C-8, all three according to the invention are distinguished only by the additional presence of organolanthanide (neodymium, cerium or samarium) in their rubber matrix (M-6 to M-8).

Landscapes

• 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)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Tires In General (AREA)
• Ropes Or Cables (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=34944564

Family Applications (1)

Country Status (8)

Cited By (28)

Families Citing this family (18)

Citations (2)

Family Cites Families (16)

• 2004
  • 2004-04-30 FR FR0404603A patent/FR2869618B1/fr not_active Expired - Lifetime
• 2005
  • 2005-04-29 US US11/579,228 patent/US20080026244A1/en not_active Abandoned
  • 2005-04-29 EP EP05736921.7A patent/EP1749055B1/fr not_active Expired - Lifetime
  • 2005-04-29 CN CN2005800218886A patent/CN1976987B/zh not_active Expired - Fee Related
  • 2005-04-29 WO PCT/EP2005/004613 patent/WO2005113666A1/fr not_active Ceased
  • 2005-04-29 JP JP2007509976A patent/JP4959551B2/ja not_active Expired - Fee Related
  • 2005-04-29 BR BRPI0510368-1A patent/BRPI0510368A/pt not_active Application Discontinuation
• 2006
  • 2006-11-30 KR KR1020067025275A patent/KR101216981B1/ko not_active Expired - Fee Related
• 2009
  • 2009-12-01 US US12/628,935 patent/US20100168306A1/en not_active Abandoned

Patent Citations (2)

Also Published As

Similar Documents

Legal Events