Classifications

• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/062—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration
  • D07B1/0633—Reinforcing cords for rubber or plastic articles the reinforcing cords being characterised by the strand configuration having a multiple-layer configuration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B15/00—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00
  • B29B15/08—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00 of reinforcements or fillers
  • B29B15/10—Coating or impregnating independently of the moulding or shaping step
  • B29B15/12—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length
  • B29B15/122—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length with a matrix in liquid form, e.g. as melt, solution or latex
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B15/00—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00
  • B29B15/08—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00 of reinforcements or fillers
  • B29B15/10—Coating or impregnating independently of the moulding or shaping step
  • B29B15/12—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length
  • B29B15/14—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length of filaments or wires
• • 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
• • 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
  • C08K3/10—Metal compounds
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
  • D07B1/0606—Reinforcing cords for rubber or plastic articles
  • D07B1/0666—Reinforcing cords for rubber or plastic articles the wires being characterised by an anti-corrosive or adhesion promoting coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2021/00—Use of unspecified rubbers as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/201—Wires or filaments characterised by a coating
  • D07B2201/2012—Wires or filaments characterised by a coating comprising polymers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/201—Wires or filaments characterised by a coating
  • D07B2201/2013—Wires or filaments characterised by a coating comprising multiple layers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2042—Strands characterised by a coating
  • D07B2201/2044—Strands characterised by a coating comprising polymers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2015—Strands
  • D07B2201/2042—Strands characterised by a coating
  • D07B2201/2045—Strands characterised by a coating comprising multiple layers
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/20—Organic high polymers
  • D07B2205/2039—Polyesters
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/20—Organic high polymers
  • D07B2205/2046—Polyamides, e.g. nylons
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/20—Organic high polymers
  • D07B2205/2075—Rubbers, i.e. elastomers
  • D07B2205/2078—Rubbers, i.e. elastomers being of natural origin
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2205/00—Rope or cable materials
  • D07B2205/20—Organic high polymers
  • D07B2205/2075—Rubbers, i.e. elastomers
  • D07B2205/2082—Rubbers, i.e. elastomers being of synthetic nature, e.g. chloroprene
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2501/00—Application field
  • D07B2501/20—Application field related to ropes or cables
  • D07B2501/2046—Tire 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
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
• • 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
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2938—Coating on discrete and individual rods, strands or filaments
• • 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
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
  • Y10T428/2942—Plural coatings
  • Y10T428/2947—Synthetic resin or polymer in plural coatings, each of different type
• • 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
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/298—Physical dimension

Definitions

• the field of the present invention is that reinforcing elements or "reinforcements", in particular metal, used for reinforcing articles or semi-finished products of diene rubber such as for example pneumatic tires.
• the present invention relates more particularly to reinforcements of the hybrid or composite type consisting of at least one core, in particular metal, said core being sheathed or covered with one or more layers of polymer.
• thermoplastic polymers such as for example polyamide or polyester
• various sets of son or wire assemblies such as cables, and thus increase their particular buckling resistance.
• patent application EP 0 962 576 describes a reinforcement made of steel or aramid textile sheathed with a thermoplastic material such as polyester or polyamide, in order to improve its resistance to abrasion.
• the patent application FR 2 601 293 has described the sheathing of a wire rope with polyamide for use as a bead wire in a tire bead, this sheath advantageously making it possible to adapt the shape of this bead wire to the structure and operating conditions of the bead of the tire that it reinforces.
• These reinforcements and sheathed polyester or polyamide material have, in addition to the aforementioned advantages of corrosion resistance, abrasion resistance and structural rigidity, that not insignificant to be then glued to matrices of diene rubber using simple textile adhesives known as "RFL" (resorcinol-formaldehyde latex) comprising at least one diene elastomer such as natural rubber, adhesives which, in known manner, confer a satisfactory adhesion between textile fibers such as polyester or polyamide fibers and a diene rubber .
• RTL resorcinol-formaldehyde latex
• metal reinforcements not coated with adhesive metal layers such as brass, as well as surrounding rubber matrices devoid of metal salts such as cobalt salts, which are necessary in a manner known to maintain adhesive performance over time can advantageously be used.
• metal salts such as cobalt salts
• the RFL glues above are not without drawbacks; they include in particular as a basic substance formaldehyde (or formaldehyde) that it is desirable to eventually remove adhesive compositions, because of the recent evolution of European regulations on this type of product.
• designers of diene rubber articles, including tire manufacturers are looking today for new adhesive systems or new reinforcements that overcomes all or part of the aforementioned drawbacks.
• a first object of the invention relates to a composite reinforcement comprising:
• the invention also relates to a method of manufacturing the composite reinforcement above, said method comprising at least the following steps: the wire or each reinforcing wire, or collectively several reinforcing wires, is covered individually by a first layer of the thermoplastic polymer whose glass transition temperature is positive; depositing on the first layer a second layer comprising the functionalized diene elastomer carrying functional groups selected from epoxide, carboxyl, anhydride or acid ester groups;
• thermo-oxidative treatment the whole is subjected to a thermo-oxidative treatment.
• the present invention also relates to the use of the composite reinforcement of the invention as a reinforcing element for semi-finished articles or rubber products, particularly pneumatic tires, in particular those intended for equipping tourism-type motor vehicles, SUVs.
• Sport Utility Vehicles two wheels (including bicycles, motorcycles), aircraft, such as industrial vehicles chosen from light trucks, "heavy goods vehicles” - that is to say, subway, bus, road transport equipment (trucks, tractors, trailers), off-the-road vehicles such as agricultural or civil engineering -, other transport or handling vehicles.
• the invention also relates per se to any article or semi-finished product made of rubber, in particular a tire, comprising a composite reinforcement according to the invention.
• 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).
• the composite reinforcement of the invention capable of adhering directly to an unsaturated rubber composition and used in particular for reinforcing diene rubber articles such as pneumatic tires, therefore has the essential characteristics of comprising: at least one yarn (that is to say one or more son) of reinforcement;
• thermoplastic polymer whose glass transition temperature is positive (that is to say greater than 0 ° C);
• the composite reinforcement of the invention comprises a single thread or several reinforcing threads, each reinforcing thread being covered (individually or collectively) by two separate polymer layers and superimposed on contact with each other. the other.
• the structure of the reinforcement of the invention is described in detail below.
• the term "reinforcing thread” is generally understood to mean any elongate element of great length relative to its cross section, whatever the shape of the latter, for example circular, oblong, rectangular or square.
• this wire may be rectilinear as non-rectilinear, for example twisted or corrugated.
• This reinforcing wire may take any known shape, it may be for example a single elementary filament large diameter (for example and preferably equal to or greater than 50 ⁇ ), an elementary ribbon, a fiber multifilament (consisting of a plurality of elementary filaments of small diameter, typically less than 30 ⁇ ), a textile twist formed of several fibers twisted together, a textile or metal cable formed of several fibers or monofilaments cabled or twisted together, or an assembly, a row of son such as for example a strip or strip comprising several of these monofilaments, fibers, twisted or cables grouped together, for example aligned in a main direction, rectilinear or not.
• the wire or each reinforcing wire has a diameter which is preferably less than 5 mm, in particular within a range of 0.1 to 2 mm.
• the reinforcing wire is a metal reinforcing wire, in particular carbon steel such as those used in steel cord type cables for tires; but it is of course possible to use other steels, for example stainless steels.
• carbon steel When a carbon steel is used, its carbon content is preferably between 0.4% and 1.2%, especially between 0.5% and 1.1%.
• the invention applies in particular to any steel of the steel cord type with standard resistance (called “NT” for “Normal Tensile"), with high resistance (called “HT” for “High Tensile”), with very high resistance ( said “SHT” for “Super High Tensile") as ultra-high resistance (so-called “UHT” for "Ultra High Tensile”).
• the metal reinforcing wire is in the form of a cable comprising at least two (that is to say two or more) metal monofilaments assembled together, more particularly carbon steel.
• the steel could be coated with an adhesive layer such as brass or zinc.
• an adhesive layer such as brass or zinc.
• the rubber composition to be reinforced by a metal reinforcement according to the invention no longer requires the use in its formulation of metal salts such as cobalt salts.
• the first layer or sheath covering the or each reinforcing wire is constituted by a thermoplastic polymer whose glass transition temperature (Tg) is by definition positive, preferably greater than + 20 ° C, more preferably greater than + 30 ° C.
• the melting point ("Tf") of this thermoplastic polymer is preferably greater than 100 ° C., more preferably greater than 150 ° C., in particular greater than 200 ° C., a function notably of the nature (in particular textile or metal) of the material constituting the reinforcing wire.
• This thermoplastic polymer is preferably chosen from the group consisting of polyamides, polyesters and polyimides, more particularly from the group consisting of aliphatic polyamides and polyesters.
• polyesters that may be mentioned for example are PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT (polypropylene terephthalate), PPN (polypropylene naphthalate).
• PET polyethylene terephthalate
• PEN polyethylene naphthalate
• PBT polybutylene terephthalate
• PBN polybutylene naphthalate
• PPT polypropylene terephthalate
• PPN polypropylene naphthalate
• aliphatic polyamides mention may be made especially polyamides 4-6, 6, 6-6, 1 1 where 12.
• This thermoplastic polymer is preferably an aliphatic polyamide, more preferably a 6-6 polyamide (Nylon ® or 6-6) .
• the second layer covering the first layer, and therefore in direct contact with the latter, consists of a functionalized diene elastomer, said elastomer carrying functional groups chosen from epoxide, carboxyl, anhydride or acid ester groups or functional groups.
• the functional groups are epoxide groups, that is to say that the diene elastomer is an epoxide diene elastomer.
• elastomer or rubber both terms being known in a known manner and interchangeable
• dienes monomers carriers of two carbon-carbon double bonds, conjugated or not
• diene elastomers which are non-thermoplastic by definition in the present application, having a Tg in the vast majority of cases which is negative (that is to say less than 0 ° C.), can be classified in a known manner into two categories. : those said to be “essentially unsaturated” and those termed "essentially saturated”.
• Butyl rubbers such as, for example, copolymers of dienes and alpha-olefins of the EPDM type, fall into the category of essentially saturated diene elastomers having a diene origin ratio which is low or very low, always less than 15. % (mole%).
• essentially unsaturated diene elastomer is 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% (mol%).
• conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (mol%).
• 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%.
• At least one diene elastomer of the highly unsaturated type in particular a diene elastomer chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), polybutadienes (BR) and butadiene copolymers, copolymers of isoprene and mixtures of these elastomers.
• a diene elastomer chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), polybutadienes (BR) and butadiene copolymers, copolymers of isoprene and mixtures of these elastomers.
• Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR), isoprene-butadiene-copolymers styrene (SBIR) and mixtures of such copolymers.
• SBR butadiene-styrene copolymers
• BIR isoprene-butadiene copolymers
• SIR isoprene-styrene copolymers
• SBIR isoprene-butadiene-copolymers styrene
• the above diene elastomers can be, for example, block, random, block, microsequential, and be prepared in dispersion or in solution; they may be coupled and / or starred or functionalized with a coupling agent and / or starring or functionalization.
• Polybutadienes and in particular those having a 1,2-unit content of between 4% and 80%, or those having a cis-1,4 content of greater than 80%, polyisoprenes and copolymers of butadiene- styrene and in particular those having a styrene content of between 5% and 50% by weight and more particularly between 20% and 40%), a 1,2-butadiene content of the butadiene part of between 4% and 65%. %, a trans-1,4-linkage content of between 20% and 80%, butadiene-isoprene copolymers and in particular those having an isoprene content of between 5% and 90% by weight and a glass transition temperature.
• the isoprene-styrene copolymers and especially those having a styrene content of between 5% and 50% by weight and a Tg between -25 ° C and -50 ° C.
• butadiene-styrene-isoprene copolymers those having a styrene content of between 5% and 50% by weight and more particularly of between 10% and 40%, and an isoprene content of between 15% and 60% by weight and more particularly between 20% and 50%, a butadiene content of between 5% and 50% by weight and more particularly between 20% and 40%, a content of -1,2 units of the butadiene part.
• thermoplastic polymers and diene elastomers described above is measured in a known manner by DSC (Differential Scanning Calorimetry), for example and unless otherwise indicated in the present application, according to ASTM D3418 of 1999.
• a second essential characteristic of the diene elastomer used in the composite reinforcement of the invention is that it is functionalized and carries functional groups chosen from epoxide, carboxyl, anhydride or acid ester groups or functional groups.
• Such functionalized diene elastomers and processes for obtaining them are well known to those skilled in the art and commercially available. Diene elastomers carrying carboxyl groups have been described for example in WO 01/92402 or US 6815473, WO 2004/096865 or US 7312264; diene elastomers bearing epoxide groups have been described for example in US 2003/120007 or EP 0763564, US 6903165 or EP 1403287.
• the functional groups are epoxide groups, that is to say that the diene elastomer is an epoxide diene elastomer. More preferably still, the epoxidized diene elastomer is chosen from the group consisting of epoxidized natural rubbers (NR), epoxidized synthetic polyisoprenes (IR) and epoxidized polybutadienes (BR), preferably having a cis-1,4 bond ratio. greater than 90%, epoxidized butadiene-styrene copolymers (SBR) and mixtures of these elastomers.
• NR epoxidized natural rubbers
• IR epoxidized synthetic polyisoprenes
• BR epoxidized polybutadienes
• SBR epoxidized butadiene-styrene copolymers
• Natural rubbers can be obtained in known manner by epoxidation of the natural rubber, for example by chlorohydrin or bromohydrin-based processes or processes based on hydrogen peroxides, alkyl hydroperoxides or peracids (such as peracetic acid or performic acid); such ENR are for example sold under the names “ENR-25” and “ENR-50” (epoxidation rate of 25% and 50% respectively) by the company Guthrie Polymer.
• the epoxidized BRs are also well known, sold for example by the company Sartomer under the name "Poly Bd” (for example “Poly Bd 605E”).
• Epoxidized SBRs can be prepared by epoxidation techniques well known to those skilled in the art.
• the rate (mol%) of functionalization, in particular of epoxidation, of the functionalized diene elastomers described above may vary to a large extent according to the particular embodiments of the invention, preferably in a range from 5% to 60%).
• the epoxidation rate is less than 5%, the intended technical effect may be insufficient while above 60%, the molecular weight of the polymer decreases sharply.
• the degree of functionalization, especially epoxidation is more preferably in a range of 10% to 50%.
• the diene elastomers epoxidized previously described are known in solid manner at room temperature (20 ° C); solid means any substance which does not have the capacity to take up, at the latest after 24 hours, under the sole effect of gravity and at ambient temperature (20 ° C.), the shape of the container which contains it .
• these solid elastomers are characterized by a very high viscosity: their Mooney viscosity in the raw state (ie, no crosslinked), denoted ML (1 + 4), measured at 100 ° C., is preferably greater than 20, more preferably greater than 30, in particular between 30 and 130.
• ML (1 + 4 Mooney viscosity in the raw state
• an oscillating consistometer as described in US Pat. ASTM D1646 (1999). The measurement is made according to the following principle: the sample analyzed in the uncured state (ie, before firing) is molded (shaped) in a cylindrical chamber heated to a given temperature (for example 100 ° C.).
• FIG. 1 shows very schematically (without respecting a specific scale), in cross section, a first example of a composite reinforcement according to the invention.
• This composite reinforcement denoted R1 consists of a reinforcing thread (10) consisting of a unitary filament or monofilament of relatively large diameter (for example between 0.10 and 0.50 mm), for example carbon steel, which is covered with a first layer (11) of a thermoplastic polymer whose Tg is positive, for example polyamide or polyester, whose minimum thickness is noted E ml in this figure 1.
• FIG. 2 schematizes in cross-section a second example of a composite reinforcement according to the invention.
• This composite reinforcement denoted R-2 consists of a reinforcing thread (20) consisting in fact of two single filaments or monofilaments (20a, 20b) of relatively large diameter (for example between 0.10 and 0.50 mm) twisted or wired together, for example carbon steel; the reinforcing wire (20) is covered with a first layer (21) of a thermoplastic polymer whose Tg is positive, for example polyamide 6-6 or polyester, minimum thickness E ml .
• FIG. 3 schematizes in cross-section another example of composite reinforcement according to the invention.
• This composite reinforcement denoted R-3 consists of three reinforcing threads (30) each consisting of two monofilaments (30a, 30b) of relatively large diameter (for example between 0.10 and 0.50 mm) twisted or cabled together, for example carbon steel; the assembly consisting of the three reinforcing son (30) for example aligned is covered with a first layer (31) of a thermoplastic polymer whose Tg is positive, for example polyamide or polyester.
• FIG. 1 a functionalized diene elastomer
• This composite reinforcement R-4 comprises a reinforcing thread (40) consisting of a 1 + 6 structural steel wire, with a core wire or core wire (41a) and six filaments (41b) of the same diameter wound together in a helix around the central wire.
• This reinforcing wire or wire (40) is covered with a first layer (42) of a polyamide 6-6, itself covered with a second layer (43) of a functionalized diene elastomer, for example a BR , SBR or epoxidized NR.
• the minimum thickness of the two layers can vary to a very large extent depending on the conditions particular embodiments of the invention.
• the minimum thickness E ml of the first layer is preferably between 1 ⁇ and 2 mm, more preferably between 10 ⁇ and 1 mm.
• the minimum thickness E i of the second layer may be of the same order of magnitude as that of the first layer (in the case of a second thick layer of a thickness, for example between 1 ⁇ and 2 mm, in particular between 10 ⁇ and 1 mm), or be significantly different.
• the second layer could constitute for example a thin or ultrafine adhesive layer, deposited for example, not by extrusion but by a coating technique, by spraying, or other deposition technique.
• a thin or ultrafine adhesive layer deposited for example, not by extrusion but by a coating technique, by spraying, or other deposition technique.
• thin or ultra-thin film for example of thickness included in a range of
• the first and second layers can be deposited individually on each of the reinforcement threads (as a reminder, whether these reinforcing threads are unitary or not), as illustrated for example in FIGS.
• first and second layers can also be collectively deposited on several appropriately arranged reinforcing wires, for example aligned in a main direction, as illustrated for example in FIG.
• the composite reinforcement of the invention may be prepared according to a specific process comprising at least the following steps: in a first step, at least one (i.e. one or more) reinforcing thread is first subjected to a first coating by the first thermoplastic polymer layer whose glass transition temperature is positive;
• thermo-oxidative treatment finally, the whole is subjected to a thermo-oxidative treatment.
• the first two steps can be conducted in a manner known to those skilled in the art, online and continuously, or not; they consist for example to pass the reinforcing wire, through dies of suitable diameter, in extrusion heads heated to appropriate temperatures.
• the wire or each reinforcing wire (taken individually or collectively) is preheated, for example by induction or by IR radiation, before passing through the first extrusion head delivering the thermoplastic polymer.
• the wire or each reinforcing wire thus sheathed is then cooled sufficiently so as to solidify the polymer layer, for example with air or another cold gas, or by passing through a bath of water. followed by a drying step.
• the or each reinforcement yarn thus sheathed and cooled is then covered by the functionalized diene elastomer, by passing through a coating bath of appropriate dimensions.
• the next step consists of a heat-oxidizing treatment intended to better secure the two layers.
• thermaloxidant treatment is meant by definition a heat treatment in the presence of oxygen, for example oxygen from the air.
• the polyamide melted at a temperature of 290 ° C in the extruder, thus covers the reinforcing wire, through the cladding head, to a thread running speed typically equal to several tens of m / min, for an extrusion pump flow typically of several tens of cm 3 / min.
• the wire can be immersed in a cooling tank filled with cold water, to solidify and freeze the polyamide in its amorphous state, then dried for example by passing the receiving coil to the oven.
• the cable (reinforcing wire) is advantageously preheated before passing through the extrusion head, for example by passing through an HF generator or through a heating tunnel.
• the yarn thus covered with polyamide is then covered with the functionalized diene elastomer according to an embodiment adapted to the thickness intended for the second layer.
• the polyamide-coated wire passes, for example at a speed of a few cm / min or tens of m / min and over a length of a few cm or tens of cm, between two felt wool felt pressed by a mass of 1 kg and continuously soaked with the functionalized diene elastomer diluted in a suitable solvent (For example BR, SBR or epoxidized NR 5% diluted in toluene), so as to cover the whole with an ultra-thin layer of functionalized diene elastomer.
• a suitable solvent for example BR, SBR or epoxidized NR 5% diluted in toluene
• the composite wire passes through a tunnel furnace, for example several meters long, to undergo a heat treatment under air.
• This treatment temperature is for example between 150 ° C and 300 ° C for treatment times of a few seconds to a few minutes depending on the case, it being understood that the duration of the treatment will be shorter as the temperature will be high and that the heat treatment obviously does not lead to excessive reflow or softening of the polymeric materials used.
• the composite reinforcement of the invention is advantageously cooled, for example in air, to avoid possible parasitic bonding problems during its winding on the final receiving coil.
• the previously described steps of the process of the invention may optionally be completed by a final three-dimensional curing treatment of the reinforcement, more precisely of its second diene functionalized elastomer layer, to further reinforce its own cohesion.
• This crosslinking may be carried out by any known means, for example by physical crosslinking means such as ionic or electronic bombardment, or by chemical crosslinking means.
• Crosslinking may also be obtained during the baking of pneumatic tires (or more generally rubber articles) that the composite reinforcement of the invention is intended to reinforce, thanks to the own crosslinking system present in the diene rubber compositions constituting such bandages (or articles) and coming into contact with the composite reinforcement of the invention.
• the composite reinforcement of the invention can be used directly, that is to say without requiring any additional adhesive system, as a reinforcing element of a diene rubber matrix, for example in a tire. It is advantageously used for the reinforcement of pneumatic tires of all types of vehicles, in particular passenger vehicles or industrial vehicles such as heavy goods vehicles.
• FIG. 5 shows very schematically (without respecting a specific scale) a radial section of a tire according to the invention for a tourism type vehicle.
• This tire 1 has a crown 2 reinforced by a crown reinforcement or belt 6, two sidewalls 3 and two beads 4, each of these beads 4 being reinforced with a rod 5.
• the crown 2 is surmounted by a tread represented 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 of 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 halfway between the two beads 4 and passes through the middle of the crown reinforcement 6).
• This tire 1 of the invention for example has the essential feature that at least one of its crown or carcass reinforcement comprises a composite reinforcement according to the invention.
• it is the rods 5 which could consist of a composite reinforcement according to the invention.
• Test 1 Manufacture of Composite Reinforcements Composite reinforcements, whether or not in accordance with the invention, are first made in the following manner.
• the starting reinforcing thread is a steel cord (called “steel cord”) for pneumatic tires (standard steel with 0.7% by weight of carbon), of 1x2 construction consisting of two elementary or monofilaments of diameter 0, 30 mm twisted together at a pitch of 10 mm. Its diameter is 0.6 mm.
• the covering of this cable with polyamide 6-6 is carried out on an extrusion-cladding line by passing through a extrusion head heated to a temperature of 300 ° C and comprising two dies, an upstream die diameter 0.63 mm and a downstream die diameter 0.92 mm.
• the polyamide heated to a temperature of about 290 ° C in the extruder (pump flow of 20 cm 3 / min) thus covers the wire (preheated to about 280-290 ° C by passing through an HF generator) running at a speed of 30 m / min.
• the composite reinforcement obtained is continuously immersed in a cooling tank filled with water at 5 ° C. in order to freeze it in its amorphous state, then dried by an air nozzle.
• the glass transition temperature of the polymer used above is equal to approximately + 50 ° C. (for example according to the following procedure: Mettler Toledo DSC apparatus "822-2", helium atmosphere, sample previously heated from room temperature (20 ° C) at 100 ° C (20 ° C / min), then rapidly cooled to -140 ° C, before final recording of the DSC curve from -140 ° C to + 250 ° C at 20 ° C / min).
• control composite reinforcement (thus not in accordance with the invention) consisting of the starting steel cable wrapped only with its first layer of polyamide.
• This composite composite reinforcement (denoted R-5) has a total diameter (ie, once sheathed) of approximately 1.0 mm.
• the cable covered with polyamide 6-6 is passed through a coating bath, at a speed of about 4 m / min, over a length of about 15 cm, between two wool felt with a mass of 1 kg and continuously soaked with the epoxy diene elastomer diluted to 5% by weight in toluene, so as to cover the whole with an ultra-thin layer of elastomer.
• the reinforcement thus sheathed is then dried to remove the solvent by evaporation.
• the assembly (double-sheathed composite reinforcement) is subjected to a heat-oxidative treatment of a duration of about 100 s, by passing at 3 m / min in a tunnel furnace, under ambient atmosphere, brought to a temperature of 270 ° C.
• a composite reinforcement according to the invention consisting of the starting steel cable sheathed with its first polyamide layer and its second epoxy diene elastomer layer.
• the composite reinforcement according to the invention thus prepared (reinforcement R-2 as shown diagrammatically in FIG. 2) has a total final diameter of approximately 1.1 mm.
• epoxidized diene elastomers were used, namely an epoxidized polybutadiene (BR) ("Poly bd” 605E from Sartomer), an epoxidized NR ("ENR-50” from International Malaysia SDB). BHD) and finally an epoxidized SBR (epoxidation rate equal to 11% (mol), Tg -40 ° C, 28% of styrene, 55% of 1,4 bonds and 17% 1,2 bonds).
• BR epoxidized polybutadiene
• EMR-50 International Malaysia SDB
• the quality of the bond between the rubber and the composite reinforcements previously manufactured is then assessed by a test in which the force necessary to extract the reinforcements of a vulcanized rubber composition, also called a vulcanizate, is measured.
• This rubber composition is a conventional composition used for calendering tire belt metal plies, based on natural rubber, carbon black and conventional additives.
• the vulcanizate is a rubber block consisting of two plates of dimensions 200 mm by 4.5 mm and thickness 3.5 mm, applied one on the other before firing (the thickness of the resulting block is then 7 mm).
• this block It is during the manufacture of this block that the composite reinforcements (15 strands in total) are trapped between the two rubber plates in the raw state, equidistant and leaving to go over on both sides of these plates a composite reinforcing end of sufficient length for subsequent traction.
• the block comprising the reinforcements is then placed in a suitable mold and then cooked under pressure.
• the temperature and the cooking time are adapted to the targeted test conditions and left to the initiative of those skilled in the art; for example, in this case, the firing of the block is carried out at 160 ° C for 15 min, at a pressure of 16 bar.
• the test thus formed of the vulcanized block and the reinforcements is put in place in the jaws of a traction machine adapted to allow each reinforcement to be pulled apart from the rubber, at a speed and given temperature (for example, in the present case at 50 mm / min and 20 ° C).
• the adhesion levels are characterized by measuring the so-called pulling force (denoted F max ) for tearing the reinforcements from the specimen (average over 15 pulls).
• the composite reinforcements of the invention despite the fact that they are free of RFL glue (or any other glue), had a particularly high and unexpected pulling force F max , always greater than the force of reference tear measured on the nylon-coated control composite reinforcement (R-5) and glued with a conventional RFL glue: at room temperature (25 ° C) and for a relative base of 100 on the R-5 composite composite reinforcement , the composite reinforcements of the invention, with a second layer respectively of epoxidized NR, BR and SBR, had a tearing force F max increased by 20%, 50% and 190%, compared to the composite control reinforcement R-5.
• control composite reinforcement sheathed in nylon but lacking RFL glue (or any other glue), had a zero adhesion to the rubber (peel force virtually equal to zero).
• the composite reinforcement of the invention by its self-adhesive nature is a particularly interesting alternative, given the very high levels of adhesion obtained, the composite reinforcements of the prior art sheathed by a thermoplastic material such as polyamide or polyester, requiring in known manner the use of an RFL-type adhesive to ensure their adhesion to rubber.

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• Mechanical Engineering (AREA)
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• Polymers & Plastics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
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• Organic Chemistry (AREA)
• Ropes Or Cables (AREA)
• Tires In General (AREA)
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• 2010
  • 2010-08-05 FR FR1056465A patent/FR2963579B1/fr not_active Expired - Fee Related
• 2011
  • 2011-06-23 EP EP11727975.2A patent/EP2601058A1/fr not_active Withdrawn
  • 2011-06-23 WO PCT/EP2011/060543 patent/WO2012016757A1/fr active Application Filing
  • 2011-06-23 JP JP2013522157A patent/JP5782514B2/ja not_active Expired - Fee Related
  • 2011-06-23 US US13/814,443 patent/US8968871B2/en not_active Expired - Fee Related
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