Classifications

• • 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
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/08—Heat treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/38—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre
• • 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
• • 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
  • B60C9/005—Reinforcements made of different materials, e.g. hybrid or composite cords
• • 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
  • B60C9/0064—Reinforcements comprising monofilaments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/38—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre
  • B29D2030/381—Textile inserts, e.g. cord or canvas layers, for tyres; Treatment of inserts prior to building the tyre the inserts incorporating reinforcing parallel cords; manufacture thereof
• • 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
  • B60C9/02—Carcasses
  • B60C9/04—Carcasses the reinforcing cords of each carcass ply arranged in a substantially parallel relationship
  • B60C2009/0416—Physical properties or dimensions of the carcass cords
• • 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
  • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
  • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
  • B60C2009/2074—Physical properties or dimension of the belt cord
• • 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
  • C08J2477/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers
  • C08J2477/10—Polyamides derived from aromatically bound amino and carboxyl groups of amino carboxylic acids or of polyamines and polycarboxylic acids

Definitions

• TITLE Reinforced product obtained by a process comprising a step of heat treatment of the sheath
• the invention relates to a reinforced product comprising one or more reinforcing elements covered with an elastomeric composition, a finished or semi-finished article comprising this reinforced product and a tire comprising this reinforced product.
• These reinforced products or reinforced semi-finished articles can be used in particular to reinforce finished articles or complex finished or semi-finished articles made of elastomers such as, for example, tires for motor vehicles, non-pneumatic tires, conveyor belts or caterpillars.
• a reinforced product comprising an elastomer matrix, several reinforcing elements embedded in the elastomer matrix, the reinforcing elements being arranged side by side in a main direction, each reinforcing element comprising: a wire element, and a sheath covering the wire element and comprising a layer of a thermoplastic polymeric composition.
• This reinforced product is intended in particular to reinforce finished articles or complex finished or semi-finished articles made of elastomers and in particular tire plies.
• the sheathed reinforcing elements are generally arranged inside the ply, in the same plane when the ply is laid flat, parallel to each other and regularly spaced. They can also be inclined, so that they form a given angle with the longitudinal direction of the tablecloth.
• sheathed reinforcing elements are used which are previously wound and stored on a plurality of reels. Then, the manufacture of the ply includes a step during which this plurality of sheathed reinforcing elements is unwound from the plurality of reels. The sheathed reinforcing elements are then arranged, as described above, parallel to the longitudinal direction of the ply during manufacture, then embedded in a layer of uncured rubber using a calendering or extrusion process.
• a ply comprising sheathed reinforcing elements forming a given angle with the longitudinal direction is obtained by cutting along a bevel of the given angle and at regular intervals a ply obtained at the end of the embedding step, then by assembling cutouts by their uncut edges.
• the storage of sheathed reinforcing elements on a reel causes deformation of the sheathed reinforcing elements. Indeed, the trajectory formed by the sheathed reinforcing elements, unwound from the coil after storage and free of any external stress, is slightly curvilinear.
• the straightness defect measured according to a method which will be described later in the description and with reference to FIG. 5 below, is called the hanger.
• the hanger of the sheathed reinforcing elements results in defects in the shape of the sheet in which the sheathed reinforcing element or elements are arranged, such as undulations, tendrils, rebiquage, an inaccurate cutting into sections of the sheet , or even a difficult arrangement and butting of a section of the ply on the tire blank.
• An object of the invention is to reduce the shape defects of a reinforced product comprising one or more reinforcing element(s) covered with a sheath.
• the subject of the invention is a reinforced product which can be used in particular for reinforcing a finished elastomer article, in which said reinforced product comprises one or more reinforcing element(s) covered with a sheath, the reinforced product is obtained by a process comprising a heat treatment step at a temperature T greater than or equal to the glass transition temperature Tg of the sheath, measured according to ISO 11357-2 of 2020.
• Any interval of values designated by the expression “between a and b” represents the range of values going from more than a to less than b (that is to say limits a and b excluded) while any interval of values designated by the expression “from a to b” means the range of values going from the limit "a” to the limit "b", that is to say including the strict limits "a” and "b ".
• the compounds comprising carbon mentioned in the description may be of fossil origin or biosourced. In the latter case, they can be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass. This concerns in particular polymers, plasticizers, fillers, etc.
• the reinforcing element covered with a sheath has a significant reduction in the hanger.
• reinforcing element an element allowing the mechanical reinforcement of a matrix in which this reinforcing element is intended to be embedded.
• elastomer or rubber, the two terms being considered synonymous
• Diene elastomers which in the vast majority of cases have a negative Tg, that is to say less than 0° C., can be classified in a known manner into two categories: those called “essentially unsaturated” and those said to be “essentially saturated”.
• essentially unsaturated diene elastomer 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% (% by moles).
• conjugated diene monomers having a rate of units or units of diene origin (conjugated dienes) which is greater than 15% (% by moles).
• highly unsaturated diene elastomer in particular means a diene elastomer having a content of units of diene origin (conjugated dienes) which is greater than 50%.
• diene elastomer means elastomers having a low or very low rate of units of diene origin, always less than 15% (% by moles), such as butyl rubbers, such as example copolymers of dienes and alpha-olefins of the EPDM type.
• diene elastomer more particularly means, whatever the category above, capable of being used in the finished article in accordance with the invention:
• the other monomer can be ethylene, an olefin or a diene, conjugated or not.
• a copolymer mention may be made of the ethylene-butadiene elastomer, or ethylene-butadiene rubber (EBR) according to the Anglo-Saxon terminology.
• diene elastomer capable of being used in the finished article in accordance with the invention is understood to mean:
• (c1) a ternary copolymer obtained by copolymerization of ethylene, an ⁇ -olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having 6 to 12 carbon atoms, such as for example the elastomers obtained from ethylene, propylene with a non-conjugated diene monomer of the aforementioned type such as in particular 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene;
• Suitable in particular as conjugated dienes are 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-di(C1-C5 alkyl)-1,3-butadienes such as by 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl -1,3-butadiene, an aryl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene.
• Suitable vinyl aromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the commercial "vinyl-toluene" mixture, para-tert-butylstyrene, 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 aromatic vinyl units.
• 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), copolymers butadiene, isoprene copolymers and mixtures of these elastomers.
• a diene elastomer chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), polybutadienes (BR), copolymers butadiene, isoprene copolymers and mixtures of these elastomers.
• Such copolymers are more preferably chosen from the group consisting of butadiene-styrene (SBR) copolymers, isoprene-butadiene (BIR) copolymers, isoprene-styrene (SIR) copolymers, isoprene- butadiene-styrene (SBIR) and mixtures of such copolymers.
• SBR butadiene-styrene
• BIR isoprene-butadiene
• SIR isoprene-styrene copolymers
• SBIR isoprene-butadiene-styrene
• Polybutadienes are preferably suitable and in particular those having a content of -1,2 units of between 4% and 80% or those having a content of cis-1,4 greater than 80%, polyisoprenes, 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 content of -1,2 bonds of the butadiene part of between 4% and 65 % , a trans-1,4 bond 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 of - 40°C to -80°C, isoprene-styrene copolymers and in particular those having a styrene content of between 5% and 50% by weight and a Tg of between -25°C and -50°C.
• butadiene-styrene-isoprene copolymers suitable in particular are those having a styrene content of between 5% and 50% by weight and more particularly between 10% and 40%, 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 of between 20% and 40%, a content of -1,2 units of the part butadiene of between 4% and 85%, a content of -1,4 trans units of the butadiene part of between 6% and 80%, a content of -1,2 plus -3,4 units of the isoprene part of between 5 % and 70% and a content of -1,4 trans units of the isoprene part of between 10% and 50%, and more generally any butadiene-styrene-isoprene copolymer having a Tg of between -20°C and 70°C.
• the elastomers can have any microstructure which depends on the polymerization conditions used, in particular the presence or absence of a modifying and/or randomizing agent and the quantities of modifying and/or randomizing agent used.
• the elastomers can for example be prepared in dispersion or in solution; they can be coupled and/or starred or further functionalized with a coupling and/or starring or functionalizing agent.
• the reinforcing element comprises one or more wire element(s) and a sheath individually covering the wire element or collectively several wire elements.
• the sheath may comprise one or more layers, each layer being based on a polymeric composition, for example as described in WO2010/136389, WO2010/105975, WO2011/012521, WO2011/051204, WO2012/016757, WO2012/038340, WO2012/038341, WO2012/069346, WO2012/104279, WO2012/104280 and WO2012/104281.
• wire element we mean an element having a length at least 10 times greater than the largest dimension of its section, whatever the shape of the latter: circular, elliptical, oblong, polygonal, in particular rectangular or square or oval. In the case of a rectangular section, the wire element has the shape of a strip. [036]
• the wire element can be metallic or non-metallic.
• the temperature T is strictly lower than the melting temperature Tf of the sheath, measured according to the ISO 11357-3 standard of 2020.
• the sheath comprises a thermoplastic polymer composition.
• the sheath comprises a single layer of the thermoplastic polymeric composition.
• the sheath comprises several layers, at least one of them comprising a thermoplastic polymeric composition.
• thermoplastic polymer composition is meant a composition comprising at least one polymer having the properties of a thermoplastic polymer.
• the composition may optionally comprise, in addition, other thermoplastic polymers, elastomers and other non-polymeric components.
• thermoplastic polymers useful for the preparation of the sheath a thermoplastic polymer preferably chosen from the group consisting of polyamides, polyesters and polyimides, more particularly from the group consisting of aliphatic polyamides and polyesters.
• polyesters mention may be made, for example, of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PBT (polybutylene terephthalate), PBN (polybutylene naphthalate), PPT (polypropylene terephthalate), PPN (polypropylene naphthalate).
• aliphatic polyamides mention may in particular be made of polyamides 4-6, 6, 6-6, 11 or 12.
• This thermoplastic polymer is preferably an aliphatic polyamide, more preferably a polyamide 6, 6-6 or a polyamide 11.
• the elastomers that can be used in the thermoplastic composition of the sheath can preferably be of two types: styrenic thermoplastic elastomers and functionalized diene elastomers. These two types of elastomers are described below.
• thermoplastic styrenic elastomers are thermoplastic elastomers in the form of block copolymers based on styrene. With an intermediate structure between thermoplastic polymers and elastomers, they consist in known manner of rigid polystyrene blocks connected by flexible elastomer blocks, for example polybutadiene, polyisoprene or poly(ethylene/butylene).
• TPS copolymers are generally characterized by the presence of two glass transition peaks, the first peak (lowest temperature, negative) being relative to the elastomer block of the TPS copolymer, the second peak (highest temperature, positive, typically around 80° C. or more) relating to the thermoplastic part (styrene blocks) of the TPS copolymer.
• the first peak lowest temperature, negative
• the second peak highest temperature, positive, typically around 80° C. or more
• Tg relating to the first peak.
• These TPS elastomers are often triblock elastomers with two rigid segments connected by a flexible segment. Rigid and flexible segments can be linear, star or branched.
• TPS elastomers can also be diblock elastomers with a single rigid segment connected to a flexible segment.
• each of these segments or blocks contains at least more than 5, generally more than 10 base units (for example styrene units and isoprene units for a styrene/isoprene/styrene block copolymer).
• base units for example styrene units and isoprene units for a styrene/isoprene/styrene block copolymer.
• random diene copolymer elastomers such as, for example, SIR rubbers (styrene-isoprene copolymers) or SBR rubbers (styrene-butadiene copolymers) which in a well-known manner have no thermoplastic character. .
• the TPS useful for the preparation of the sheath is preferably unsaturated.
• unsaturated TPS elastomer is meant by definition and in a well-known manner a TPS elastomer which is provided with ethylenic unsaturations, that is to say which comprises carbon-carbon double bonds (conjugated or not); conversely, a so-called saturated TPS elastomer is of course a TPS elastomer which is devoid of such double bonds.
• the TPS useful for the preparation of the sheath is functionalized, bearing functional groups chosen from epoxide, carboxyl, anhydride or acid ester groups or functions.
• this TPS elastomer is an epoxidized elastomer, that is to say bearing one or more epoxide groups.
• the TPS useful for preparing the sheath is chosen from the group consisting of styrene/butadiene (SB), styrene/isoprene (SI), styrene/butadiene/butylene (SBB), styrene / butadiene/ isoprene (SBI), styrene/ butadiene/ styrene (SBS), styrene/ butadiene/ butylene/ styrene (SBBS), styrene/ isoprene/ styrene (SIS), styrene/ butadiene/ isoprene/ styrene (SBIS) and mixtures of these copolymers.
• TPS elastomers are commercially available.
• unsaturated and epoxidized SBS mention may be made of "Epofriend", which is known and commercially
• a functionalized diene elastomer will be chosen, for example and preferably, said elastomer carrying functional groups chosen from epoxide, carboxyl, anhydride or acid ester groups or functions.
• the functional groups are epoxide groups, that is to say that the diene elastomer is an epoxidized diene elastomer.
• poly (p phenylene ether) (or PPE) useful for the preparation of the sheath one will choose for example and preferably an PPE chosen from the group consisting of poly (2,6-dimethyl-1, 4-phenylene-ether), poly(2,6-dimethyl-co-2,3,6-trimethyl-1,4-phenylene-ether), poly-(2,3,6-trimethyl-1,4-phenylene -ether), poly(2,6-diethyl-1,4-phenylene-ether), poly(2-methyl-6-ethyl-1,4-phenylene-ether), poly(2-methyl-6-propyl- 1,4-phenylene-ether), poly-(2,6-dipropyl-1,4-phenylene-ether), poly(2-ethyl-6-propyl-1,4-phenylene-ether), poly(2, 6-dilauryl-1,4-phenylene-ether), poly(2,6-diphenyl-1,4-phenylene-ether), poly(2,6-diphenyl-1
• the PPE used is poly(2,6-dimethyl-1,4-phenylene-ether), also sometimes called polyphenylene oxide (or, for short, “PPO”).
• PPEs or PPOs are, for example, the PPEs with the name “Xyron S202” from the company Asahi Kasei, or the PPEs with the name “Noryl SA120” from the company Sabic.
• the sheath comprising a thermoplastic polymeric composition as described above can be self-adhesive, that is to say its composition can be such that it has very good adhesion. to the surrounding rubber composition, without requiring the use of an adhesive composition.
• thermoplastic polymeric composition as a self-adhesive sheath is described in applications WO2010/136389, WO2010/105975, WO2011/012521, WO2011/051204, WO2012/016757, WO2012/038340, WO2012/038341, WO2012/069346, WO2012/104279, WO2012/104280, WO2012/104281, WO2013/117474 and WO2013/117475.
• the sheath is coated with a layer based on an adhesive composition based on a resin and a latex of elastomer(s).
• the layer based on an adhesive composition is formed by a layer based on a resin and a latex of elastomer(s). Mention will be made of adhesive compositions of the RFL (Resorcinol-Formaldehyde-Latex) type, but also the adhesive compositions as described in WO2015118041.
• RFL Resorcinol-Formaldehyde-Latex
• thermoplastic polymeric composition is chosen from the group consisting of polyamides, polyesters and polyimides, preferably from the group consisting of aliphatic polyamides and polyesters.
• the thermoplastic polymeric composition is a polyamide and preferably a polyamide 6-6.
• the reinforced product comprising a polyamide 6.6 sheath allows good industrial processability and in particular good operation in pneumatics.
• the heat treatment step is done for a time t between 0 excluded and 60 seconds, preferably between 0 excluded and 20 seconds and more preferably between 0 excluded and 5 seconds. This very short heat treatment step is sufficient to significantly reduce the hanger of the reinforced product.
• the heat treatment step is carried out at a running speed of the reinforced product ranging from 5 meters per minute to 120 meters per minute and preferably from 10 meters per minute to 80 meters per minute.
• the heat treatment step can thus, with short durations and a high running speed, be implemented upstream of a calendering step between a step of unrolling the reinforced product from a storage reel and the step of calendering in which the reinforced product is embedded in an elastomeric composition.
• the reinforcing element or elements are non-metallic.
• a non-metallic filamentary element can be an elementary textile monofilament.
• This elementary textile monofilament is obtained, for example, by melt spinning, solution spinning or gel spinning.
• Each elementary textile monofilament is made of an organic, in particular polymeric, or inorganic material, such as for example glass, quartz, basalt or carbon.
• the polymeric materials can be of the thermoplastic type, such as for example aliphatic polyamides, in particular polyamides 6-6, and polyesters, in particular polyethylene terephthalate.
• the polymeric materials can be of the non-thermoplastic type, such as aromatic polyamides, in particular aramid, and cellulose, both natural and artificial, in particular rayon.
• Each elementary textile monofilament has a substantially circular cross-section having a diameter ranging for example from 2 ⁇ m to 100 ⁇ m.
• a non-metallic wire element can be an assembly of several elementary textile monofilaments as defined above, also called strand.
• a strand preferably comprises more than 10 elementary textile monofilaments, preferably more than 100 elementary textile monofilaments and more preferentially more than 500 elementary textile monofilaments.
• a non-metallic wire element can also be an assembly of several strands as defined above.
• Said non-metallic wire element is advantageously of the polyester type, advantageously of the polyethylene terephthalate, polyamide, glass, carbon, quartz or basalt type.
• the reinforcing element(s) are metallic(s).
• the reinforcing element is one or more metal wire element(s).
• the metallic wire element can be an elementary metallic monofilament.
• Such an elementary metallic monofilament comprises a steel core, optionally coated with one or more layers of a coating which may be metallic and/or based on a non-metallic adhesive composition.
• the metallic coating comprises a metal chosen from among zinc, copper, tin, cobalt and alloys of these metals. Examples of alloys of these metals include brass and bronze.
• the core steel is a carbon steel comprising between 0.1% and 1.2% carbon by mass, at most 11% by mass chromium, less than 1% by mass of each of the following elements: manganese , silicon, aluminum, boron, cobalt, copper, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, phosphorus, sulfur, nitrogen, the rest being iron and unavoidable impurities resulting from the elaboration. Steel can have a pearlitic, ferritic, austenitic, bainitic, martensitic microstructure or a microstructure resulting from a mixture of these microstructures.
• the metallic elementary monofilament has a mechanical strength ranging from 1000 MPa to 5000 MPa.
• Such mechanical strengths correspond to the steel grades commonly encountered in the field of tires, namely, NT (Normal Tensile), HT (High Tensile), ST (Super Tensile), SHT (Super High Tensile), UT ( Ultra Tensile), UHT (Ultra High Tensile) and MT (Mega Tensile), the use of high mechanical strength possibly allowing improved reinforcement of the matrix in which the reinforcing element is intended to be embedded and a lightening of the matrix thus strengthened.
• the diameter of this elementary metallic monofilament preferably ranges from 0.05 mm to 0.60 mm.
• the metallic wire element can be an assembly of several elementary metallic monofilaments as described above, assembled together in a helix, for example by cabling or twisting the elementary metallic monofilaments to forming, for example, layered cables comprising several concentric layers of elementary metallic monofilaments or stranded cables, each strand comprising several concentric layers of elementary metallic monofilaments.
• a metallic wire element comprises a layer based on a polymeric composition, preferably on a composition comprising an elastomer, this layer being placed between two layers of elementary metallic monofilaments of the coated cable or a strand of the stranded cable.
• the diameter of the metal wire element ranges from 0.05 mm to 0.60 mm.
• Another object of the invention is a method for treating a reinforced product as defined previously which comprises a heat treatment treatment step of said reinforced product comprising one or more reinforcing element(s) covered with a sheath at a temperature T greater than or equal to the glass transition temperature Tg of the sheath, measured according to ISO 11357-2 of 2020.
• the method may include a step during which the reinforced product is unrolled from a storage means on which the reinforced product is rolled up.
• the method may include a step during which the reinforced product is stored on a storage means on which the reinforced product is rolled up.
• the method may include a step during which the reinforced product is embedded in an elastomeric composition in order to obtain a semi-finished article according to the 'invention.
• Another object of the invention is a finished or semi-finished article comprising a reinforced product as defined above.
• the reinforced product(s) as defined above are themselves embedded in a rubber composition known as rubber coating.
• the so-called coating gum rubber composition comprises a diene elastomer mainly comprising an elastomer chosen from the group consisting of natural rubber, synthetic polyisoprene or a mixture of the latter.
• a finished article means any type of rubber article such as a ball, a non-pneumatic object such as a non-pneumatic tire, a conveyor belt or a caterpillar.
• Another object of the invention is a tire comprising a reinforced product as described above, preferably at least in one ply chosen from crown reinforcement plies and carcass plies.
• FIG. 1 is a sectional view perpendicular to the circumferential direction of a tire according to the invention
• FIG. 2 is a sectional view of a semi-finished article according to the invention.
• FIG. 3 is a sectional view of a reinforced product according to the invention.
• FIG. 4 shows the measurement of the hanger C of a sample of a reinforcing element covered with a sheath
• FIG. 5 is a schematic representation of the manufacturing process of the reinforced product according to the invention.
• FIG. 1 there is shown an X, Y, Z mark corresponding to the usual orientations respectively axial (X), radial (Y) and circumferential (Z) of a tire.
• the “median circumferential plane” M of the tire is the plane which is normal to the axis of rotation of the tire and which is located equidistant from the annular reinforcing structures of each bead.
• FIG. 1 a tire according to the invention and designated by the general reference 10.
• the tire 10 is here intended for a passenger vehicle or a heavy vehicle such as a truck.
• the tire 10 comprises a crown 12 comprising a crown reinforcement 14 comprising a working reinforcement 15 comprising two working plies 16, 18 of reinforcing elements and a hooping reinforcement 17 comprising a hooping ply 19.
• crown reinforcement 14 is surmounted by a tread 20.
• the hooping reinforcement 17, here the hooping ply 19, is radially interposed between the working reinforcement 15 and the tread 20.
• Two flanks 22 extend the top 12 radially inward.
• the tire 10 further comprises two beads 24 radially inside the sidewalls 22 and each comprising an annular reinforcing structure 26, in this case a bead wire 28, surmounted by a mass of rubber 30 for stuffing, as well as a carcass reinforcement radial 32.
• the crown reinforcement 14 is radially interposed between the carcass reinforcement 32 and the tread 20.
• Each sidewall 22 connects each bead 24 to the crown 14.
• the carcass reinforcement 32 preferably comprises a single carcass ply 34 of radial textile reinforcement elements.
• the carcass reinforcement 32 is anchored to each of the beads 24 by turning around the bead wire 28 so as to form in each bead 24 a go strand 38 extending from the beads 24 through the sidewalls 22 into the crown 12 , and a return strand 40, the radially outer end 42 of the return strand 40 being radially outside the annular reinforcing structure 26.
• the carcass reinforcement 32 thus extends from the beads 24 through the sidewalls 22 into the crown 12. In this embodiment, the carcass reinforcement 32 also extends axially through the crown 12.
• Each working ply 16, 18 forms a reinforced product R according to the invention comprising reinforcing elements 44 forming an angle ranging from 15° and 40°, preferably ranging from 20° to 30° and here equal to 26 ° with the circumferential direction of the tire 10.
• the reinforcing elements 44 are crossed from one working ply to the other.
• the hooping ply 19 comprises textile hooping reinforcement elements forming an angle at most equal to 10°, preferably ranging from 5° to 10° with the circumferential direction of the tire 10.
• the working plies 16, 18, hooping 19 and carcass 34 comprise an elastomer matrix 23 in which the reinforcing elements of the corresponding ply are embedded.
• the rubber compositions of the elastomer matrices 23 of the working 16, 18, hooping 19 and carcass 34 plies can be conventional compositions for coating reinforcing elements conventionally comprising a diene elastomer, for example natural rubber, a reinforcing filler, for example carbon black and/or silica, a cross-linking system, for example a vulcanization system, preferably comprising sulphur, stearic acid and zinc oxide , and optionally an accelerator and/or a vulcanization retarder and/or various additives.
• At least one of the layers comprising a reinforced product comprises a reinforced product according to the invention.
• this web comprises a coating composition 23 specific to the invention, that is to say a composition as defined above and below for the purposes of the invention.
• EXAMPLE OF A FINISHED OR SEMI-FINISHED ARTICLE ACCORDING TO THE INVENTION [092] There is shown in FIG. 2 a semi-finished article according to the invention and designated by the general reference 50.
• the semi-finished article 50 comprises at least one reinforcing element 33, covered with a sheath G, in this case several reinforcing elements 33, covered with a sheath G, embedded in the polymer matrix 102.
• the polymer matrix 102 the reinforcing element 33, covered with a sheath G in an X, Y, Z frame in which the Y direction is the radial direction and the X and Z are the axial and circumferential directions.
• the reinforced product 100 comprises several reinforcing elements 33, covered with a sheath G arranged side by side in the main direction X and extending parallel to each other within the semi-finished article 50 and collectively embedded in the polymeric matrix 102.
• the polymeric matrix 102 is an elastomeric matrix based on an elastomeric composition.
• FIG. 3 a reinforced product according to the invention and designated by the general reference R.
• the reinforced product R comprises at least one reinforcing element 33, covered of a sheath G.
• the reinforcing element 33 is a 9.30, that is to say an assembly of several metallic wire elements assembled together in a helix, here 2 metallic son assembled together in a helix forming a first layer and 7 metallic son wound around of the first layer to form a second layer.
• the sheath G consists of a thermoplastic polymeric composition chosen from the group consisting of polyamides, polyesters and polyimides, preferably from the group consisting of aliphatic polyamides and polyesters.
• the thermoplastic polymeric composition is a polyamide and here it is a polyamide 6-6.
• the sheath G is in contact with the reinforcing element 33.
• FIG. 4 shows the method for manufacturing the reinforced product R according to the invention and the process for manufacturing the semi-finished product 50 according to the invention.
• This method may comprise a step ET1 during which the reinforced product R is unrolled from a storage means on which the reinforced product is rolled up.
• the storage means is most often a storage reel comprising a hub and two flanges.
• the size of the coil depends on the reinforcement stored and represents a compromise between the quantity of reinforcement which it is desired to have available and the constraints linked to the use of a process or to transport. Dimensions are standardized to facilitate their usage. Reels particularly useful for the purposes of the invention have a hub diameter of between 100 mm and 200 mm.
• a plurality of reinforced products R are unwound from a plurality of reels.
• This heat treatment is carried out at a time t between 0 excluded and 60 seconds, preferably between 0 excluded and 20 seconds and more preferably between 0 excluded and 5 seconds.
• the time is 0.75 seconds.
• the heat treatment step is done at a speed ranging from 5 meters per minute to 120 meters per minute and preferably from 10 meters per minute to 80 meters per minute, here the speed is 60 meters per minute.
• the heat treatment can be implemented by any means known to those skilled in the art.
• the reinforced product can be heated by conduction, convection, induction, preferably by induction.
• the reinforced product preferably passes through a chamber in which the heating means is applied, the dimensions of the chamber and the running speed determining the duration of the heat treatment.
• the duration of the heat treatment of the process according to the invention makes it possible to maintain the calendering speeds commonly used in industrial processes, in particular tire manufacturing processes.
• each reinforced product can be treated individually, or else the plurality of reinforced products can be treated collectively.
• the plurality of reinforced product is treated collectively. This particularly preferred arrangement allows efficient industrial implementation by collectively processing reinforced products of various origins and various hangers with a reduced processing cost by minimizing the number of heat treatment equipment.
• the reinforced product R thus obtained feeds a step ET3 in which it is embedded in an elastomeric composition in order to obtain a semi-finished article 50 according to the invention.
• the elastomeric composition is based on a composition comprising at least one elastomer and at least one filler.
• the composition comprises an elastomer, preferably a diene elastomer.
• elastomer preferably a diene elastomer.
• diene elastomer or indistinctly rubber, whether natural or synthetic, must be understood in a known manner an elastomer consisting at least in part (ie, a homopolymer or a copolymer) of diene monomer units (monomers bearing two carbon-carbon double bonds, conjugated or not).
• isoprene elastomer is understood to mean in known manner an isoprene homopolymer or copolymer, in other words a diene elastomer chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), various isoprene copolymers and mixtures of these elastomers.
• NR natural rubber
• IR synthetic polyisoprenes
• the diene elastomer is preferably chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), butadiene-styrene copolymers (SBR), copolymers of isoprene-butadiene (BIR), isoprene-styrene (SIR) copolymers, butadiene-styrene-isoprene (SBIR) copolymers and mixtures of these elastomers, and very preferably chosen from natural rubber and a synthetic polyisoprene of cis-1,4 type.
• the composition may comprise a single or more diene elastomer(s), also all or part of the additives usually used in the matrices intended for the manufacture of tires, such as for example fillers such as carbon black or silica, coupling agents, anti-aging agents, antioxidants, plasticizers or extender oils, whether the latter are aromatic or non-aromatic in nature (including very low or non-aromatic oils, for example of the naphthenic or paraffinic type, with high or preferably low viscosity, MES or TDAE oils), plasticizing resins with a high glass transition temperature (above 30°C), agents facilitating the implementation (processability) of raw state compositions, tackifying resins, anti-reversion agents, methylene acceptors and donors such as for example HMT (hexamethylenetetramine) or H3M (hexamethoxymethylmelamine), reinforcing resins (such as resorcinol or bismaleimide), known adhesion promoter systems of the metal salt type
• the crosslinking system of the elastomeric composition is a so-called vulcanization system, that is to say based on sulfur (or a sulfur-donating agent) and a primary vulcanization accelerator .
• a vulcanization system can be added various known secondary accelerators or vulcanization activators.
• the sulfur is used at a preferential rate of between 0.5 and 10 phr
• the primary vulcanization accelerator for example a sulfenamide
• the content of reinforcing filler for example carbon black and/or silica, is preferably greater than 30 phr, in particular between 30 and 100 phr.
• Suitable carbon blacks are all carbon blacks, in particular blacks of the HAF, ISAF, SAF type conventionally used in tires (so-called tire-grade blacks). Among the latter, mention will more particularly be made of carbon blacks of grade (ASTM) 300, 600 or 700 (for example N326, N330, N347, N375, N683, N772).
• Suitable silicas are in particular precipitated or fumed silicas having a BET surface area of less than 450 m2/g, preferably from 30 to 400 m2/g.
• each polymer matrix has, in the crosslinked state, a secant modulus in extension, at 10% elongation, which is between 4 and 25 MPa, more preferably between 4 and 20 MPa; values comprised in particular between 5 and 15 MPa have proved to be particularly suitable.
• the modulus measurements are carried out in tension, unless otherwise indicated according to the ASTM D 412 standard of 1998 ("C" test piece): the secant modulus is measured in second elongation (that is to say after an accommodation cycle). "true” (i.e. reduced to the actual section of the specimen) at 10% elongation, noted here as Ms and expressed in MPa (normal conditions of temperature and humidity according to standard ASTM D 1349 of 1999).
• the plurality of reinforced product is arranged parallel to each other.
• the plurality of reinforced product thus arranged is then embedded in the elastomeric composition.
• the step in which the reinforced product or the plurality of reinforced product is embedded in the elastomeric composition can be carried out by any method known to those skilled in the art, for example by extrusion or calendering.
• the method according to the invention makes it possible to put 50 semi-finished articles of various origins which may have taken various hangers during their manufacture and/or their storage on coil, and thus greatly facilitates the management of reinforced product supplies and the manufacture of semi-finished articles.
• the semi-finished article obtained, comprising at least one reinforced product, has a flatness compatible with its incorporation into a process for manufacturing a tire blank.
• the manufacture of a tire blank comprises a step of manufacturing at least one semi-finished article according to the method of the invention.
• the method then comprises at least one step during which the semi-finished article or articles are wound on a building drum so as to obtain a tire blank. More precisely, the semi-finished articles are arranged circularly on the blank of tire being manufactured then the two ends of the semi-finished article are butted.
• the hanger C of the sample of reinforced product R' is measured as shown in FIG. 4, the sample of reinforced product R', placed on a horizontal plane, substantially forming an arc, the arc being characterized by its deflection, or in other words, the maximum distance between the bow and the chord CO which underlies it, perpendicular to the chord.
• a reinforcement element is evaluated, noted “9.30", it is an assembly with two layers of metal wires of diameter 0.30 mm and of structure 2 + 7 and pitch 7.7 mm and 15.4 mm .
• This reinforcing element is commonly used for reinforcing semi-finished articles of pneumatic tires.
• Table 1 shows the decrease in the hanger of the reinforced product tested. A very good hanger decrease is indicated by the “++” sign and a bad hanger decrease is indicated by the “-” sign.

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