Classifications

• • 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
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
  • D02G3/04—Blended or other yarns or threads containing components made from different materials
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/48—Tyre cords
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
  • D10B2331/021—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides aromatic polyamides, e.g. aramides

Definitions

• the present invention relates to textile reinforcements that can be used in particular for reinforcing rubber articles such as tires, in particular for reinforcing crown reinforcement or carcass reinforcement of such tires.
• twisted or composite textile cords of the composite or hybrid type also sometimes called "bi-modules", made of textile materials having modules in extension, and more generally mechanical properties, notably different from a material to the other.
• Twists or hybrid textile cords consisting of two different textile materials, they have been used for a long time to improve certain properties of use, thanks to improved compromises between mechanical properties, thermal properties and fatigue resistance. .
• the disadvantage of nylon is that it has a low initial modulus in extension, particularly hot (typically 150 ° C and more), which can lead to a degradation of the rolling performance of the tires under conditions of particularly high temperatures.
• the thermal contraction of the nylon is relatively high, which may cause satisfactory design difficulties of the tire casings during their various stages of manufacture and then cooking.
• hybrid cords described in this application conventionally constructed, namely consisting of a single strand of aramid and a single strand of polyketone, preferably of the same title, which are twisted with identical twist , can be further optimized.
• the present invention relates to an aramid / polyketone composite textile cord that can be used in particular for reinforcing tires, comprising at least one multi-filament aramid strand and at least one multi-filament polycetone strand twisted together, the constituent elementary filaments.
• multifilament aramid strand being twisted according to a torsion factor Ki and the constituent elementary filaments of the multifilament strand of polyketone being twisted according to a torsion factor K 2 , characterized in that in said cord: o the weight ratio aramid / polyketone is higher at 1, 5;
• the ratio K 2 / Ki is greater than 1, 10. - -
• the invention also relates to the use of such a textile cord as a reinforcing element for semi-finished articles or rubber products such as tires, as well as these articles, semi-finished products of rubber and tires themselves, both in the raw state (that is to say before cooking or vulcanization) and in the cooked state (after cooking).
• the tires of the invention may be intended for motor vehicles of the tourism, 4x4, SUV (Sport Utility Vehicles) type, but also for two-wheeled vehicles such as motorcycles, or for industrial vehicles. selected from vans, "heavy goods vehicles” - ie, metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles -, agricultural or civil engineering machinery, airplanes, other transport vehicles or Handling.
• SUV Sport Utility Vehicles
• the textile cord of the invention is particularly intended for use in crown reinforcement (or belts) as in tire carcass reinforcement for the vehicles described above.
• 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 expression “from a to b” means the range from a to b (i.e., including the strict limits a and b).
• the cord or twine fabric of the invention is therefore an aramid / polyketone composite textile cord having at least one (that is to say one or more) strand (or fiber) multifilament aramid, and at least one (c ') that is one or more) strand (or fiber) - Multifilament polyketone which are twisted together, the constituent elementary filaments of the aramid multifilament strand being twisted according to a torsion factor Ki and the constituent elementary filaments of the polycetone multifilament strand being twisted according to a torsion factor K 2 .
• this textile cord of the invention has the following two essential characteristics: the aramid / polyketone weight ratio is greater than 1.5;
• the ratio K 2 / Ki is greater than 1, 10.
• aramid fiber By so-called “aramid” fiber, it is well known that this is a fiber of linear macro molecules formed of aromatic groups linked together by amide bonds, at least 85% of which are directly linked to two aromatic rings. and more particularly poly (p-phenylene terephthalamide) (or PPTA) fibers, manufactured for a long time from optically anisotropic spinning compositions.
• polyketone refers to a thermoplastic polymer obtained by the polycondensation of ethylene and carbon monoxide.
• the polyketone fibers have also been described in a very large number of patent documents (see for example EP 310 171, EP 456 306, EP 1 925 467, WO 2002/068738 or US 6 818 728, US 2007/0017620, US 2009/0266462).
• the aramid / polyketone weight ratio represents the ratio of the total weight of aramid material (and therefore the total weight of the strand or strands, if they are more than one, to aramid) over the total weight of polyketone material ( therefore total weight of the strand or strands, if they are several, in polyketone). According to the invention, this weight ratio is greater than 1, 5, preferably greater than 2.0, more preferably still greater than 3.0.
• the torsion factor of a multifilament strand (more exactly, constituent elementary filaments of said strand) is expressed according to the following relation:
• K (Torsion in revolutions / meter) x [(Strand title (in tex) / (1000.p)] in which the torsion is expressed in revolutions per meter of strand, the strand title is expressed in tex (weight in gram 1000 meters strand), and finally p is the density or density - -
• the K 2 / Ki ratio is greater than 1, 10, preferably greater than 1, 20, more preferably still greater than 1, 25.
• the textile cord of the invention may comprise one or more multifilament aramid yarns.
• the title of each aramid strand is between 100 and 450 tex, more preferably between 150 and 400 tex.
• the twist of each aramid strand is preferably between 150 and 400 revolutions per meter, more preferably between 200 and 350 revolutions per meter.
• the textile cord of the invention may comprise one or more multifilament strands of polyketone.
• the title of each polyketone strand is between 100 and 400 tex, more preferably between 150 and 250 tex.
• the twist of each strand of polyketone is preferably between 200 and 600 turns per meter, more preferably between 350 and 500 turns per meter.
• the composite textile cord of the invention comprises two aramid strands and a single polyketone strand.
• the cord of the invention has an initial modulus in extension, measured at 20 ° C, which is greater than 1000 cN / tex, preferably between 1300 and 2000 cN / tex.
• the cord of the invention has an end module in extension, measured at 20 ° C, which is greater than 3000 cN / tex, preferably between 3500 and 4000 cN / tex.
• the final modulus ratio of the cable to initial module of the cable, measured at 20 ° C is less than 4, more preferably between 1, 0 and 3.0.
• the initial module in extension of the cord is greater than 300 cN / tex, more preferably between 500 and 1500 cN / tex.
• the tenacity of the cord measured at 20 ° C., is preferably greater than 120 cN / tex, more preferably between 125 and 150 cN / tex.
• the composite textile cord of the invention has a thermal contraction (denoted "CT") of its length, after 2 minutes at 185 ° C., under a pretension of 0.5 cN / tex, which is between 0.2 and 2.5%, more preferably between 0.5 and 2%.
• CT thermal contraction
• CT is measured, unless otherwise specified, according to ASTM D1204-08, for example on a device of the "TESTRITE" type.
• the maximum of the contraction force (denoted F c ) during the above test (2 min at 185 ° C.) is also measured.
• the result is expressed in cN / tex, thus reduced to the title of the tested cable sample.
• This contraction force, on the composite textile cord of the invention is preferably between 2.5 cN / tex, more preferably between 1.4 and 2.0 cN / tex; a high contraction force is particularly favorable to the hooping capacity of the textile cords vis-à-vis the crown reinforcement of the tire when the latter heats up under high running speed.
• the textile cord of the invention is advantageously used for the reinforcement of tires of all types of vehicles, in particular motorcycles, passenger vehicles or industrial vehicles such as heavy vehicles, civil engineering, airplanes, other vehicles for transport or handling.
• Figure 1 shows very schematically (without respecting a specific scale), a radial section of a tire according to the invention for 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 not shown 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 a manner known per se consisting of at least one rubber ply reinforced by so-called "radial" textile cords, that is to say that these cords are arranged substantially parallel to one another and extend from one bead to the other so as to form an angle of between 80 ° and 90 ° with the median circumferential plane (plane perpendicular to the axis of rotation of the tire which is situated halfway between the two beads 4 and goes through the middle of the crown frame 6).
• the belt 6 is for example constituted, in a manner known per se, by at least two rubber sheets called “working plies” or “triangulation plies”, superimposed and crossed, reinforced with metal cables arranged substantially parallel to each other with respect to others and inclined relative to the median circumferential plane, these working plies may or may not be associated with other plies and / or fabrics of rubber. These working plies have the primary function of giving the tire a high rigidity of drift.
• the belt 6 further comprises in this example a rubber sheet called “hooping sheet” reinforced by so-called “circumferential” reinforcing son, that is to say that these reinforcing son are arranged substantially parallel to each other and extend substantially circumferentially around the tire so as to form an angle preferably within a range of 0 to 10 ° with the medial circumferential plane.
• These circumferential reinforcing son have the primary function, it is recalled, to resist the centrifugation of the top at high speed.
• This tire 1 of the invention for example has the essential feature that at least the shrinking web of its belt (6) and / or its carcass reinforcement (7) comprises a textile cord according to the invention.
• it is for example the rods (5) which could consist, in whole or in part, of a textile cord according to the invention.
• the rubber compositions used for these webs are conventional compositions for calendering textile reinforcements, typically based on natural rubber, carbon black, a vulcanization system and conventional additives.
• the adhesion between the composite textile cord of the invention and the rubber layer which coats it is ensured for example by a usual glue of the RFL type.
• FIG. 2 reproduces, in turn, force-elongation curves, denoted C1, C2 and C3, recorded on composite textile cords in the glued state, whether or not in accordance with the invention, which can be used in the examples of tires previously described.
• Curve C 1 corresponds to a composite composite textile cord noted CI: of construction denoted A / A / N (for Aramid / Aramid / Nylon), it consists of two multifilament strands in - -
• Aramid (initial title of each strand equal to 334 tex) and a multifilament nylon strand (initial title equal to 188 tex) which are twisted together at 230 turns / meter.
• Curve C2 corresponds to another composite composite textile cord noted C-II: of construction denoted A / A / P (for Aramid / Aramid / Polyketone), it consists of two strands multifilament aramid (initial title of each strand equal to 334 tex) and a polycetone multifilament strand (initial title equal to 167 tex) which are twisted together at 230 rpm.
• the construction of this cable C-II is similar to that of the cable CI, that is to say that the different strands are twisted identical torsion, as described in particular in the application WO 2008/092712 cited in the introduction of the present description .
• the curve C3 corresponds to a textile cord according to the invention denoted C-III: also of construction A / A / P, it consists of two strands multifilament aramid (initial title of each strand equal to 334 tex) and of a polycetone multifilamentary strand (initial title equal to 167 tex), which are twisted together on the one hand at 230 revolutions / meter with respect to the two aramid strands, on the other hand at 400 revolutions / meter in this case. which relates to the polyketone strand.
• each constituent strand of the final cable is first individually twisted on itself in a given direction (for example S-twist of 230 turns per meter of strand) during a first step, then that the strands thus twisted on themselves are then twisted together in the opposite direction (for example Z-twist of 230 turns per meter of strand) to obtain the final textile cords.
• a given direction for example S-twist of 230 turns per meter of strand
• the specificity of the cable of the invention (C-III), compared to the two control cords (CI and C-II), is that the polyketone strand is much more twisted on itself than the two aramid strands, when the first step. This is reflected in the final cable by a pronounced torsional imbalance: in the end, on the finished manufacturing cable, the two aramid strands are balanced in torsion (no torsion or almost no residual torsion on the aramid filaments themselves in the cable) while the strand in polyketone is still overworked on itself (residual twist of 170 turns per meter on the PK filaments themselves). With this construction, the ratio of the torsion factors (K 2 / Ki) is very clearly greater than 1.10, in this case in this example equal to about 1.29.
• the attached single table summarizes the construction and the respective properties of the three types of composite textile cords.
• Prior conditioning means the storage of the cords (after drying) for at least 24 hours, before measurement, in a standard atmosphere according to the European standard DIN EN 20139 (temperature of 20 ⁇ 2 ° C, hygrometry of 65 ⁇ 2 %).
• the titre (or linear density) of the elementary strands or cords is determined on at least three samples, each corresponding to a length of 50 m, by weighing this length; the title is given in tex (weight in grams of 1000 m of product - recall: 0, 1 1 1 tex equal to 1 denier).
• the mechanical properties in extension are measured in known manner using an "INSTRON" traction machine.
• the tested samples are pulled over an initial length of 400 mm at a nominal speed of 200 mm / min, under a standard pretension of 0.5 cN / tex. All results given are an average of 10 measurements.
• the tenacity (force-rupture divided by the title) and the modules in extension (initial module and final module) are indicated in cN / tex or centinewton by tex (for recall, 1 cN / tex equal to 0, 1 1 g / den (gram per denier)).
• the initial modulus is defined as the slope of the linear part of the Force-Elongation curve that occurs just after a standard pre-tension of 0.5 cN / tex.
• the final module is defined as the slope of the linear part of the Force-Elongation curve that occurs just before the break (end of the Force-Elongation curve).
• the elongation at break is indicated in percentage.
• hybrid cords C-II and C-III based on polyketone, have significantly improved thermal properties compared to hybrid nylon-based cable: initial high temperature module (180 ° C) superior, less thermal contraction and superior contraction force;
• this torsion imbalance significantly improves the force-rupture (F R ) and toughness (Te) properties at 20 ° C, compared to the C-II control cord; in addition, compared to the aramid-nylon reference cord (CI), the specific construction of the cord of the invention C-III makes it possible to maintain the breaking force while substantially reducing the ratio of final module / initial module;
• the cord according to the invention is the one having the highest tenacity.
• Twisting of the strands (revolutions / m) 230/230/230 230/230/230 230/230/400

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Tires In General (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Ropes Or Cables (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

Cited By (12)

Families Citing this family (11)

Citations (17)

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• 2011
  • 2011-04-28 FR FR1153632A patent/FR2974583B1/fr not_active Expired - Fee Related
• 2012
  • 2012-04-25 JP JP2014506845A patent/JP6040496B2/ja not_active Expired - Fee Related
  • 2012-04-25 CN CN201280020396.5A patent/CN103492623B/zh not_active Expired - Fee Related
  • 2012-04-25 KR KR1020137027920A patent/KR20140017629A/ko not_active Abandoned
  • 2012-04-25 US US14/113,474 patent/US20140069563A1/en not_active Abandoned
  • 2012-04-25 WO PCT/EP2012/057546 patent/WO2012146612A1/fr not_active Ceased
  • 2012-04-25 EP EP12716443.2A patent/EP2702194B1/fr not_active Not-in-force

Patent Citations (21)

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