JP4266155B2 - Tire cord and pneumatic tire - Google Patents

Description

  The present invention relates to a tire cord in which the strength and cord diameter of a joint portion obtained by joining two cord end portions are maintained at the same level as a body portion cord, and a pneumatic tire reinforced with the tire cord.

  As a reinforcing material for the carcass layer and belt reinforcement layer of pneumatic tires, a single tire cord is used so that no joint is formed between the reinforcing members in the tire circumferential direction (jointless tire), and no weft is used. It has been proposed to improve the weight and uniformity of tires by using rubber coated with a rubber cord as a reinforcing material, and the single cords used for these need to be extremely long and adhere to rubber In order to ensure dimensional stability, the cord needs to be subjected to adhesive treatment or heat treatment.

  In order to obtain such a long tire cord, a long cord is joined by a knot method that mechanically connects two cord ends or an air joint method that twists using a swirling air flow. It is generally performed (Patent Document 1).

  In addition, a single tire cord that has been treated with adhesive treatment or the like is extremely inefficient in the method of processing the cords one by one, and a large number of cords are simultaneously processed using a special device such as a cord setter. In this method, since the cords are not connected to each other by wefts, the cords are easy to move and troubles occur, and an expensive device for equalizing the tension of the cords is required. Low and high cost.

Therefore, at each end of the longitudinal direction of the interwoven fabric using the tire cord as a warp, the end of the warp is alternately connected to the end of the adjacent warp on one side, and the interwoven fabric is composed of a plurality of arbitrary warps. A cord reinforcing fabric for tire reinforcement in which a long treated tire cord can be obtained by taking out the warp yarn after the adhesive treatment is performed (Patent Document 2).
Japanese Patent Laid-Open No. 2002-362836 Japanese Patent Laid-Open No. 11-245614

  By the way, in order to fabricate a reinforcing material coated with a single tire cord and covered with rubber, for example, an extruder or a calendar device is arranged by arranging a large number of cords by means such as passing them through comb-shaped scissors or harmonica-shaped guide holes. By supplying to the rubber and topping the rubber, a long topping sheet made only of warp can be obtained, and can be suitably used as a tire reinforcing material.

  However, the long tire cord has joints by the knot method or the air joint method in some places, and when this is supplied to a topping process such as an extruder as described above, the joint protruding from the cord The knot or filament of the part may get caught in the ridge or guide hole, or the cord may break due to insufficient bonding strength.

  Once troubles such as cord breakage occur, it requires the labor and time-consuming work of disassembling the die part of the extruder, aligning the cords, and passing them through the hooks and guide holes. It is also possible to detect the joints in the cord, but in this case, it is necessary to control the operation so that the cord does not break, and to perform topping processing. There is a problem in that the topping accuracy is lowered, such as disorder of the code arrangement inside and change in thickness.

  In addition, when using the above topping sheet as a tire reinforcement, it is necessary to remove the joint part from the lack of strength of the joint part by the knot method or air joint method or the protruding part may adversely affect the tire performance. There is an increase in man-hours and material loss.

  The present invention is a processed single tire cord used as a reinforcing material for a pneumatic tire, and is a long tire capable of maintaining the strength and cord diameter of the joint portion as the main body cord by a simple joining method. A cheaper long tire cord obtained by efficiently taking out a warp as a cord from a cord fabric or a warp fabric that has been processed by joining warps at the ends of the fabric, and tire performance reinforced with the tire cord It aims at providing the pneumatic tire which secured.

  The invention according to claim 1 is a tire cord obtained by joining two cord ends made of a large number of filaments, and untwisting a portion corresponding to the joined portion of each cord end, The filaments in the shape of a bamboo basket are brought into contact with each other in an entangled state, an adhesive is applied to the entangled portion, and the filaments are entangled and aligned at the joint portion by pulling in the longitudinal direction of the cord before the adhesive is cured. The tire cord is bonded in a state.

  According to the tire cord of the present invention, since the filaments butted at the cord joint are entangled and bonded in an aligned state, the entanglement effect and the adhesive action of the adhesive are synergistic, and the strength of the joint and the cord diameter A long tire cord that maintains the same level as the main body cord can be obtained, troubles such as cord breakage during rubber topping can be prevented, and continuous operation is possible, and even if a joint is included in the tire Does not degrade performance. Furthermore, the tire cord of infinite length can be obtained by repeating joining at the end of the cord.

  According to the second aspect of the present invention, at both ends in the longitudinal direction of a long weft fabric made by weaving a warp made of a tire cord together with a weft, the ends of the warp are alternately joined to the ends of the warp adjacent to one side thereof. The warp is a tire cord obtained by taking out the warp from a comb fabric made up of a plurality of warps, wherein the warp end joint portion of the comb fabric is a portion corresponding to each warp end join portion. Twist is untwisted into a bamboo basket shape, the filaments in the bamboo basket shape are brought into contact with each other in an entangled state, an adhesive is applied to the entangled portion, and the adhesive is pulled in the longitudinal direction before the adhesive is cured. The tire cord is characterized in that the filaments are bonded in an entangled and aligned state.

  According to the tire cord of the present invention, any warp adjacent to one side at the end in the longitudinal direction of the interwoven fabric is joined and continuous. Therefore, after performing the treatment such as the adhesive treatment, the warp of the interwoven fabric By taking out the tires in order from the side end, it is possible to efficiently obtain a tire cord that is at least twice as long as the length of the interwoven fabric, maintaining the strength and cord diameter of the joint as the body cord. The manufacturing cost can be reduced.

  In the interwoven fabric, the end of each warp is joined to the end of one of the adjacent warps at one end in the fabric longitudinal direction, and at the other end in the fabric longitudinal direction, The warp yarns may be joined to the end portions of the warp yarns on the opposite side of the two adjacent warp yarns, and the respective warp yarns may be alternately continued at both ends.

  As a result, the warp yarns are alternately joined at both ends in the longitudinal direction of the fabric and are continuously connected to each other. An extremely long cord with a single warp can be obtained.

  Further, in the interwoven fabric, any odd-numbered warp counted from the side end and the even-numbered warp adjacent thereto are not joined at the end, and the non-joined end of the warp is at least one of the longitudinal direction of the fabric A plurality of long tire cords having a length more than several times the length of the interwoven fabric can be obtained.

  When these interwoven fabrics are wound in a roll shape so that the non-joined end portion of the warp is on the surface side of the wound body, the warp yarn is pulled out while pulling out the interwoven fabric from the roll-shaped wound body. The warp yarn can be pulled out from one end side in the fabric axial direction from the roll-shaped wound body so that the warp yarns joined at the fabric end portion can be pulled out successively in the axial direction. Thus, the work for taking out the warp can be performed efficiently.

  Further, these braided fabrics may be wound in a roll shape, and the non-joined end portions of the warps may be mixed on the surface side and the core side of the wound body. Also in this case, the operation of taking out the warp from the interwoven fabric can be performed efficiently as described above.

  A third aspect of the present invention is the tire cord according to the first or second aspect, wherein the cord diameter at the joint portion is 0.7 to 1.1 times the main body cord diameter.

  As a result, the cord joint can be smoothly passed without being broken due to being caught or clogged with the hook or guide hole during topping processing, avoiding troubles such as cord breakage, troublesome work at the time of trouble To improve machining efficiency. Further, the topping sheet surface does not bulge or dent in the joint, and the tire performance such as uniformity can be improved as well as the appearance of the sheet can be improved.

  The invention according to claim 4 is the tire cord according to any one of claims 1 to 3, wherein the cord strength at the joint portion is 60% or more of the body portion cord strength.

  As a result, it is possible to prevent the cord from being broken by the cord tension during the topping process, and to secure the basic tire performance such as durability without deteriorating the reinforcing property even if the joint portion is included in the tire as it is.

  A fifth aspect of the present invention is a pneumatic tire reinforced with the tire cord according to any one of the first to fourth aspects.

  According to the pneumatic tire of the present invention, the strength and the cord diameter of the cord joint portion are maintained, so even if this joint portion is included in the tire, the tire strength does not decrease and the joint portion does not become a foreign matter, and Performance such as durability and uniformity can be ensured without causing material loss, and the weight of the tire can be reduced by reducing the thickness of the seat.

   According to the tire cord of the present invention, a long tire cord that maintains the strength and cord diameter of the joint portion with respect to the main body portion cord can be obtained, and further, the end portion of the tire cord can be obtained by repeatedly joining the cord end portions. You can also get

  Also, by forming a joint between warps at the end of the interwoven fabric and taking out the warps sequentially from the side ends, a tire cord that is at least twice as long as the interwoven fabric can be obtained efficiently, and the manufacturing cost of the single tire cord Can be greatly reduced.

  In addition, this cord prevents troubles such as cord breakage at the time of topping processing, enables continuous operation, relieves troublesome recovery work when trouble occurs, and remarkably improves the production efficiency of topping sheets without wefts.

  In addition, the pneumatic tire of the present invention maintains the strength of the cord joint and the cord diameter. Therefore, even if the joint is included in the tire as it is, the tire strength is not reduced, and durability and uniformity are not reduced. Tire performance such as Mitty can be ensured and contribute to weight reduction.

  Hereinafter, the present invention will be described based on embodiments.

[First Embodiment]
FIG. 1 shows a tire cord according to the first embodiment of the present invention, and FIG. 2 schematically shows an example of a cord joining method.

  As shown in the figure, the tire cord 1 is a multifilament yarn having a fineness of 500 to 5000 dtex made of various filaments made of various synthetic fibers such as polyester, nylon, aramid, rayon, etc. Is a processed cord subjected to adhesive treatment such as RFL treatment and heat treatment.

  The tire cord 1 is a long tire cord in which two cords 11 and 12 are joined. In the joining portion 13, one cord end portion 11a and the other cord end portion 12a are abutted, and filaments are overlapped. In this state, the filaments are entangled with each other, and are bonded and firmly bonded in an aligned state without irregularities or protrusion of the filaments on the surface.

  As shown in FIG. 2, the tire cord 1 is joined by first untwisting the portion corresponding to the joint portion of both cords 11 and 12 and separating the filaments into bamboo bamboo-like states 11b and 12b (FIG. 2). 2 (b)), and then a joint 13a in an entangled state in which the bamboo basket-like filaments are butted and intertwined with each other is formed, and an adhesive 14 is applied to the joint 13a (FIG. 2C). ). After allowing the adhesive 14 to permeate the entire joining portion 13a in which the filaments are in an entangled state, the tensile force F is pulled in the longitudinal direction of the cord before the adhesive 14 is cured (FIG. 2D). In the portion 13b, the filaments at both ends of the cord are kept entangled with each other so that the bamboo basket-like filaments are pulled and substantially aligned, and the cord diameter D1 is adjusted so that the unevenness and the filament do not protrude at the joint portion 13, The adhesive 14 is cured and connected to one tire cord 1 shown in FIG.

  Examples of the method of untwisting the cord ends 11a and 12a to make the filaments into bamboo baskets 11b and 12b include a method of performing manual work using a cone and a tweezer, a method of untwisting by applying compressed air, and the like. In addition, in order to form the entangled joint portion 13a in which filaments are entangled with each other, a method of squeezing the stacked filaments with a fingertip or using compressed air is exemplified, and all of them are particularly limited. However, the method of processing by hand is the simplest.

  The adhesive 14 used for the joint part 13 is preferably a solution-type quick-drying adhesive from the viewpoint of allowing the adhesive to penetrate between the filaments of the joint part 13a in the entangled state. For example, a polyvinyl acetate system or a polyvinyl alcohol system And polyacrylic acid ester adhesives. In particular, it is preferable to use a cyanoacrylate-based one-pack type instantaneous adhesive because the bonding speed is high and a high strength adhesive force can be obtained by a simple operation at room temperature in a short time.

  The method of applying the tensile force F in the longitudinal direction of the cord before the adhesive 14 is cured is, for example, a method in which a joint is cured under a constant tension using a constant-length uniaxial tension device, or an instantaneous adhesive is used. In this case, it is easy to hold the both sides of the joint part 13 by hand, apply tension in the longitudinal direction of the cord, and cure while visually confirming the filament alignment state of the joint part 13.

  The cord diameter D1 at the joint 13 of the tire cord 1 obtained as described above is 0.7 to 1.1 times, preferably 0.8 to 1.05 times the main body cord diameter D0, and Is preferably 0.9 to 1.03 times.

  When the joint cord diameter D1 is less than 0.7 times D0, the entanglement between the filaments is insufficient and sufficient joint strength cannot be ensured, and the cord breakage due to the tension during topping and the reinforcement of the tire are reduced. If D1 exceeds 1.1 times, the probability that the joint 13 will be caught in the eye or hole of the cord when the cord 1 passes through the eyelid or the guide hole increases rapidly, and troubles such as cord breakage occur frequently. Become. Here, D1 includes a filament partially protruding from the joint portion 13.

  As a result, the cord diameter D1 of the cord joint 13 is maintained at the same level as that of the main body cord, and knot-like knots and filament whiskers of the conventional joining method are eliminated, and the joint 13 of the tire cord 1 is combed during topping. Can be prevented from being derailed from the calender roll groove without causing cord breakage or clogging of the guide hole due to being caught or clogged in the shape of a hook or harmonica-like guide hole. Free up work and improve machining efficiency. In addition, the appearance of the topping sheet can be improved without causing the joint portion 13 to bulge or dent on the sheet surface, and the tire performance such as uniformity can be improved.

  The cord strength at the joint portion 13 is preferably 60% or more of the body portion cord strength, and more preferably 70% or more. This prevents the occurrence of cord breakage due to both tensions applied from the opposite directions of the winding side and the drawing side during topping, and also reduces the reinforcement even if the joint 13 is included in the tire, particularly in the carcass layer. Thus, tire durability can be ensured.

  Further, the length L of the joint portion 13 is not particularly limited, but is about 5 to 25 mm, and is a length at which a good entangled state of the filament of the joint portion 13 is obtained and the joining strength is ensured. I just need it. If the length L is too short, a good and sufficient entangled state between the abutted filaments cannot be obtained, and the joining strength is insufficient. If it is too long, man-hours are required for the filament entanglement work and the penetration of the adhesive. This is not preferable because it tends to jump out from the joint 13 and causes the cord to break at the time of topping, such as reducing the linearity of the cord after joining.

  The tire cord 1 obtained in this way is a long tire whose joint 13 has the same strength and cord diameter as the main body cord because the entanglement effect between the filaments and the adhesive force by the adhesive exhibit a synergistic effect. It becomes a cord and can be made into an infinite length tire cord by repeating joining at the end of the cord, and it is also possible to make an infinite tire cord, and pneumatic tires without causing trouble such as cord breakage in the rubber topping process Therefore, it is possible to obtain a reinforcing material suitable for use.

  The tire cord 1 may be a single tire cord that has been processed by adhesive treatment and heat treatment after two untreated cords are joined and lengthened at the end thereof.

[Second Embodiment]
The second embodiment is a long tire cord that can be efficiently obtained by taking out, as a tire cord, a warp in which adjacent warp ends are joined from a treated comb fabric.

  FIG. 3 shows an example of the interwoven fabric 2 according to the second embodiment, and FIG. 4 is an enlarged view of a part thereof. As shown in the figure, this weave fabric 2 is made of tire cords such as polyester, nylon, aramid, rayon, etc. as warps, hundreds to thousands of warps 20 and every required distance in the longitudinal direction of these warps 20. It is woven into a long length of several tens to several thousand meters by the weft 30 that is driven into the knitting and connects the warps 20.

  The weft 30 can be woven (tuck-in method) by driving a single weft continuously by folding back at the side end of the woven fabric, or by driving a weft that has been cut back at both ends. The weft 30 driving interval does not cause problems in processing and handling such as adhesive treatment and heat treatment, and is within a range that facilitates the drawing operation of the warp yarn 20 from the interwoven fabric 2 after the treatment, for example, 10 to 100 mm. It can be set to a relatively large range.

  If the warp 20 and the weft 30 are firmly bonded to each other by the adhesive treatment, it may be difficult to separate the warp 20. Therefore, the weft 30 is subjected to a Teflon (registered trademark) coating process. The adhesiveness may be lowered.

  The interwoven fabric 2 thus woven can be easily subjected to treatments such as adhesive treatment and heat treatment required by ordinary means using a normal tire cord dipping machine.

  In the weave fabric 2 of the present invention, at both end portions a and b in the longitudinal direction of the fabric, the end portions of the warp yarn 20 are alternately joined at the end portions and both ends of the warp yarn 20 adjacent to one side thereof, so that a plurality of warp yarns are obtained. 20 is continuous. In the figure, 21 is an odd-numbered warp from one side end, 22 is an even-numbered warp from the side end, and 4 is the joint.

  As a specific form of joining of the warps 20, as shown in FIG. 3, the ends of the warps 21 or 22 are arranged at one end a in the longitudinal direction of the fabric so that the warps are alternately continued at both ends. The warp 22 or 21 on either side of the two adjacent warps and the other warp 22 or 21 on the opposite side of the warps on the other end b in the longitudinal direction of the fabric. Are joined to the end of each.

  That is, at one end a in the fabric longitudinal direction, the end 21a of the odd-numbered warp 21 is joined to the end 22a of the next even-numbered warp 22 and at the other end b in the fabric longitudinal direction, The end 22b of the even-numbered warp 22 is joined to the end 21b of the next odd-numbered warp 21, and the warps 21 and 22 are alternately continued at both ends a and b.

  In the case of the interwoven fabric 2, the warps 21 and 22 are alternately joined at both ends thereof and are continuous into one. Therefore, a long tire cord in which all the warp yarns 20 are continuous is obtained by taking out the warp yarns 20 of the interwoven fabric 2 as cords by means such as sequentially pulling out from the side ends, and the manufacturing cost of the single cord is greatly reduced. can do.

  The warp ends are joined in the same manner as in the first embodiment, that is, the filaments are untwisted at the portions corresponding to the joints of the warp ends 21a and 22a and 21b and 22b, respectively. Is made into a bamboo basket shape, and the filaments in the bamboo basket shape are butted and entangled to give an adhesive, and before the adhesive is cured, a tensile force is applied in the warp longitudinal direction so that the filaments are bonded to each other at the joint 4. This is due to being entangled and aligned.

  As a result, the tire cord taken out from the interwoven fabric 2 becomes a long tire cord having a joining strength and a cord diameter comparable to the warp yarn 20 of the fabric main body portion at the joint portion 4, and cord breakage or the like in rubber topping processing. It is suitable for a tire reinforcing material that does not cause trouble.

  The joining at the warp end is preferably performed at the start of weaving in the weaving direction of the weave fabric 2 and at the end of weaving at the end of the end. It is also possible to perform bonding at an appropriate time after weaving and before and after treatment such as adhesive treatment.

  Further, the weave fabric 2 is generally formed with tabies 6a and 6b having a width of about 50 to 150 mm and a dense density of the wefts 30 at both ends at the beginning and end of weaving. Is extended from the tabby 6a, 6b to a required length, so that it is easy to implement the present invention by joining the warp ends.

[Modification]
FIG. 5 and FIG. 6 show, as a modified example of the joining form of the interwoven fabric 2, that an arbitrary odd-numbered warp 21 counted from the side end and an even-numbered warp 22 adjacent thereto are joined at the end. In this case, the warp ends 21 and 22 are left as the non-joined ends 20a and 20b.

  5 shows a case where the end portions 21a and 22a of the non-joined warp yarns 21 and 22 are left as the non-joined end portions 20a at one end portion a in the longitudinal direction of the fabric, as shown in FIG. The soldering fabric 2b shows a case where the end 20a of the non-joined warp 20 is left at one end a in the longitudinal direction of the fabric and the end 20b of the unjoined warp 20 is left at the other end b.

  According to the weave fabrics 2a and 2b of this modification, by pulling out and taking out each warp 20 from the comb fabric in the same manner as in the second embodiment, a plurality of yarns separated at the non-joined portion at the end of the fabric ( In the case of the figure, a tire cord having a warp length of 3 or more) can be obtained.

  The location of the non-joined portion can be arbitrarily set according to the length and number of cords to be obtained from the braid fabrics 2a and 2b, and tire cords having different lengths can be taken out.

  Each of the above weave fabrics 2, 2a, 2b is usually wound into a roll shape after the treatment such as the adhesive treatment as shown in FIG. 7. At this time, the end portion 20c of the side warp 20 and the warp It is preferable that the 20 non-joining end portions 20a are wound so as to exist on the surface of the winding body 5 of the interwoven fabric 2. Thereby, for example, while pulling out the weave fabric 2 from the roll-shaped wound body 5, a method of taking out the warp 20 and obtaining a long tire cord can be easily implemented.

  Further, as shown in FIG. 8, the wound body 5 of the interwoven fabric 2 is supported on the support device 8 by releasing the one end side in the axial direction with the winding core 51 in the vertical direction, and the warp 20 is wound on the wound body. By pulling out from the upper end side of 5 in the axial direction, the warp yarns 20 can be successively drawn out from the side end portions of the interwoven fabric 2 and folded at the wound body end portion 52 to continuously take out the lower warp yarns 20. The removed warp 20 is wound around a bobbin 55 or the like through a rotatable guide member 54 and a guide roller 53. This extraction method can be easily implemented based on the method described in Japanese Patent Application Laid-Open No. 2000-199168.

  Further, as shown in FIG. 9, two winding bodies 5a and 5b of the interwoven fabric 2 are vertically set with the winding core 51 as an axis, and both ends in the axial direction are released and supported by the support device 8, and are wound. The warp end 20d at the lowermost end of the wound body 5a and the warp end 20e at the uppermost end of the wound body 5b are joined by the joining portion 4a according to the joining method of the second embodiment, and the warp 20 is wound. By successively pulling out the upper end side of the body 5a in the axial direction, the warp yarn 20 can be continuously taken out from the interwoven fabric 2 of the two wound bodies 5a, 5b, and the production efficiency of the single cord is improved and more A long cord can be obtained.

  The long tire cords obtained as in the first and second embodiments are arranged by means such as passing the required number through a guide hole, and supplied to an extruder or calendar device to top the rubber. By doing so, it is possible to obtain a long topping sheet having no weft without causing troubles such as cord breakage and derailment from the calender roll groove during processing. For example, the pneumatic tire 7 shown in FIG. The carcass layer 71, the belt layer 72, the belt reinforcing layer 74, the belt end reinforcing layer 75, the side reinforcing layer 73, and the like can be suitably used as a tire reinforcing material that eliminates the adverse effects caused by the wefts. The topping sheet is made thinner by eliminating the step due to the weft between the warp and weft that occurs when topping the fabric, contributing to weight reduction and cost reduction of the tire. It can be.

  The treated single tire cord is wound as it is in the tire molding process in a spiral shape at an angle of approximately 0 ° in the tire circumferential direction, and is then vulcanized and integrated by covering the tread and side rubber on it. Therefore, it can be used as a reinforcing cord that does not cause a joint portion in the tire circumferential direction, such as a belt reinforcing layer 74, a belt end reinforcing layer 75, and a side reinforcing layer 73.

  And when using the topping sheet or single cord as a tire reinforcing material, the joint strength and cord diameter of the cord are maintained at the same level as the main body cord. Performance such as durability and uniformity of the pneumatic tire can be ensured without causing an increase or loss of tire material.

  EXAMPLES The present invention will be further described below with reference to examples, but it goes without saying that the present invention is not limited to these examples.

[Example 1]
After two treated tire cords of nylon 66, 1400 dtex / 2 (twist number 38 times / 10 cm) are cut diagonally at both ends of the cord as shown in FIG. Use the untwisted filament to break up the bamboo basket-like filaments, then butt the filaments together in a bamboo basket shape, tie them together with your fingertips to create an entangled state, and instantly bond to this joint Apply adhesive (Aron Alpha 201, manufactured by Toa Gosei Co., Ltd.) to infiltrate the entire joint, and hold the joint in the longitudinal direction of the cord and harden the adhesive in a state of being almost aligned with the pulling filaments tangled Then, a joining portion 13 as shown in FIG. 2E was formed, and a long tire cord shown in FIG. 1 was obtained.

  The cord diameter and tensile strength of the tire cord joint and main body were measured according to JIS L1017. The results are shown in Table 1.

  Furthermore, using a long tire cord having an average of joints as described above every 150 m, as shown in a schematic diagram of the inside of the extruder base 9 in FIG. 11, a harmonica-like array in which a large number of cords 91 are arranged. Using a die throat 93 having a guide hole 95, a die insert 92 for determining rubber thickness, and a stealth stick system (made by Stealth Stick, USA) equipped with an extruder (not shown) for supplying topping rubber, cord driving density It is processed into a topping sheet 94 of 22/25 mm, rubber thickness 1.1 mm, and sheet width 10 cm, and this sheet is further slit along the cord to 8 mm width (including 7 cords) to form a tape for belt reinforcement layer A reinforcing material (A) was produced. In addition, a tape-shaped reinforcing material (B) was produced in the same manner using a tire cord having the same structure that does not include a joint, and the presence or absence of cord breakage and processability during topping processing of both cords with a stealth stick system were evaluated. The results are shown in Table 1.

  Using these tape-shaped reinforcing materials (A) and (B), the steel belt layer 72 of the pneumatic radial tire 7 shown in FIG. 10 is spirally jointless at an angle of approximately 0 ° with respect to the tire circumferential direction. Tires of size 205 / 65R15 in which the wound belt reinforcing layer 74 and belt end reinforcing layer 75 were formed were prototyped (referred to as tire A and tire B), and high-speed durability was evaluated according to the following test methods. The results are shown in Table 2.

  The carcass layer 71 was polyester, 1670 dtex / 2, one ply with a driving density of 23/25 mm, and the belt layer 72 was steel cord 2 + 2 × 0.25, two plies with a driving density of 20/25 mm.

  High-speed durability: Adjusted to 220 kPa air pressure using a standard rim, loaded with 85% of the standard load specified by JATMA, and started running at a speed of 140 km / hour using a drum testing machine equipped with a steel drum with a drum diameter of 1700 mm. The speed at the time of tire failure (Km / hour) was measured by increasing the speed by 10 km / hour every 10 minutes. The result was expressed as an index in which the speed at the time of failure occurrence was set with tire B as 100. Further, the tire after running was disassembled, and the failure state and the presence or absence of occurrence of cord breakage in the belt reinforcing layers 74 and 75 were observed.

  As is clear from Table 1, the cord diameter of the joint is slightly smaller than that of the main body, and it smoothly passes through the guide hole of the stealth tic system during topping, and the tensile strength is maintained at 95% of that of the main body. There was no cord breakage due to back tension, and there was no problem in processability. Further, as shown in Table 2, tire A including the joint has sufficient high-speed durability equal to tire B not including the joint by sufficiently securing the strength of the belt reinforcing layer. It can be seen that the separation due to the adhesion failure of the part and no cord breakage occurred, and the high-speed durability performance of the tire A is comparable to the tire B.

[Example 2]
A long tire cord having a treated portion of 1670 dtex / 2 (twisted number 45 times / 10 cm) having polyester joined at an average of every 200 m joined in the same manner as in Example 1 was prepared. Using this cord, a stealth stick system was used to topp the sheet into a sheet having a cord driving density of 23/25 mm, a rubber thickness of 1.2 mm, and a sheet width of 20 cm. The carcass reinforcing material (C) was prepared by joining the sheet pieces cut into parallel and butt-jointed, and the carcass reinforcing material (D) was similarly prepared using the tire cord having the same structure not including the joint portion. . Using these carcass reinforcements (C) and (D), one ply is applied to the carcass layer 71 of the pneumatic radial tire shown in FIG. 10, and tires of size 185 / 70R14 are prototyped (tires C and D). To do). The belt layer 72 was made of two plies of steel cord 2 + 2 × 0.25 and a driving density of 20 pieces / 25 mm.

  The presence or absence of cord breakage and processability during topping of both cords were evaluated, and the high load durability of tires C and D was evaluated according to the following test method. The results are shown in Table 3.

  High load durability: A drum tester equipped with a steel drum with a drum diameter of 1700 mm, adjusted to a pneumatic pressure of 220 kPa using a standard rim, and loaded with 90% of the standard load specified by JATMA at a speed of 120 Km / hr. After running for 10 hours, the vehicle was run for 10 hours at 100% standard load and then for 22 hours at 110% standard load. If no failure occurred, the running time was extended and the vehicle was run until a tire failure occurred. . The distance traveled until the failure occurred was expressed as an index with tire D as 100, and the tire after running was disassembled and the failure state was observed.

  As shown in Table 3, there was no cord breakage during topping for both cords, and there was no problem in processability. In addition, tire C and tire D have approximately the same high load durability, and the failure mode is due to adhesion failure (separation) of the carcass winding end, and the durability performance of tire C and tire D is equivalent. It can be said that there is.

[Example 3]
Polyester, 1670 dtex / 2 (twisted 45 times / 10 cm) braided fabric with warp yarn (cord driving density 23/25 mm, weaving width 1 m, weaving length 500 m, weft 30th cotton yarn, weft driving interval 2 cm) Was made. At this time, the warp ends at both ends of the interwoven fabric are joined as shown in the interdigital fabric 2 in FIG. 3 by the same joining method as in Example 1, so that the warp of the entire fabric becomes a continuous cord. A junction was formed.

  Next, RFL adhesive treatment and heat treatment were processed using a dipping machine according to a conventional method to obtain a braided fabric of the treated tire cord. From the wound body of this fabric, warp yarns were formed on the side end portions by the method shown in FIG. The tire cord was sequentially taken out from the tire to obtain a long tire cord.

  In this tire cord taking-out operation, all warp yarns could be taken out as a single tire cord from the entire interwoven fabric without causing breakage of the cord or taking-out trouble at the joint.

  Further, a carcass reinforcing material (C) of Example 2 was produced using this tire cord. At this time, in the topping process using the stealth stick system, all cords could be topped without causing any trouble such as cord breakage. In other words, even in the tire cord obtained by taking out the warp from the weave fabric, it shows that there is no abnormality such as a decrease in the strength of the cord joint or an increase in the cord gauge, which greatly increases the production efficiency of the single cord. It is possible to improve the cost of single code.

  The tire cord of the present invention is a long single tire cord that maintains the strength and cord diameter of the cord joint with respect to the main body cord, and can efficiently produce a weft-free topping sheet. It can be used as a reinforcing material for various parts such as a carcass, a belt, a belt reinforcing layer, and a sidewall. It is also useful as a reinforcing material for industrial articles other than tires and vehicle parts, such as industrial belts, air springs, and automotive flexible couplings.

It is a front view showing a tire cord of an example. It is a schematic diagram explaining the joining method of the tire cord of an Example. It is the top view which abbreviate | omitted one part which shows the textile fabric of an Example. It is an enlarged view same as the above. It is the top view which abbreviate | omitted one part which shows the textile fabric of another Example. Furthermore, it is the top view which abbreviate | omitted one part which shows the textile fabric of another Example. It is the perspective view which wound the interwoven fabric of the Example of FIG. 5 in roll shape. It is a perspective view which shows the outline of one example of the drawing-out method of a warp. It is a perspective view which shows the outline of the other example of the method of taking out a warp. It is a half sectional view of a pneumatic radial tire of an example. It is the schematic which shows the inside of an extruder die.

Explanation of symbols

1,11,12 ... Tire cord 13 ... Joint part 14 ... Adhesive 2,2a, 2b ... Insulating fabric 4 ... Insulating fabric end part 5 ... Roll wound body 7 ... Pneumatic radial tire 20 …… Warn 21… Odd number warp 22 …… Even number warp 30 …… Weft

Claims (5)

A tire cord obtained by joining two cord ends made of a large number of filaments,
Untwisting the portion corresponding to the joint portion of each cord end into a bamboo basket shape, butting the filaments in the bamboo basket shape together to give an adhesive agent to the interlaced portion, Before being cured, the tire cord is stretched in the longitudinal direction of the cord, and the filaments are entangled and aligned in the joining portion. At both ends in the longitudinal direction of a long comb weaving a warp made of tire cord together with wefts, the ends of the warps are alternately joined with the ends of the warps adjacent to one side thereof, so that a plurality of warps are formed. A tire cord obtained by taking out the warp from a continuous weave fabric,
The joints of the warp end portions of the interwoven fabric are untwisted at portions corresponding to the joint portions of the respective warp ends to form bamboo baskets, and the filaments in the bamboo baskets are butted together to form an entanglement state. The tire cord is characterized in that an adhesive is applied to the portion and is pulled in the longitudinal direction of the warp before the adhesive is cured, and the filaments are entangled and aligned in the joint portion. The tire cord according to claim 1 or 2, wherein a cord diameter in the joint portion is 0.7 to 1.1 times a main body cord diameter. The tire cord according to any one of claims 1 to 3, wherein a cord strength at the joint portion is 60% or more of a body portion cord strength. A pneumatic tire reinforced with the tire cord according to claim 1.

Images