JP2008285785A - Cord for reinforcing rubber article, and tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To give a new cord structure improved in rubber permeability and excellent in durability and anti-corrosion property in the cord obtained by twisting a plurality of sheath strands consisting of a plurality of filaments around a core strand consisting of the plurality of the filaments. <P>SOLUTION: This cord obtained by twisting the plurality of the sheath strands consisting of the plurality of the filaments around the core strand consisting of the multiple number of the filaments, is provided with a polymer layer between the core strand and sheath strand, and an opening part exposing the core strand partially is provided in the polymer layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cord used as a reinforcing material for rubber articles such as tires and industrial belts, and a tire to which the cord is applied, and in particular, a cord with improved durability and corrosion resistance, and weight reduction using the cord. And a tire that achieves high durability.

  Tires, especially tires for construction vehicles, have many opportunities to travel on rough rough surfaces such as protrusions or rocks while being loaded with heavy loads, so the cords used to reinforce the tires can withstand that load and the harsh environment. Therefore, it is necessary to increase the breaking strength. Therefore, the structure adopted for this cord is a so-called double twisted structure in which a plurality of strands obtained by twisting a plurality of filaments are further twisted, and the breaking strength can be increased by increasing the cross-sectional area of the cord. It is common. Here, the breaking strength means the maximum tensile load until the cord breaks in a tensile test based on JIS G 3510 and JIS Z 2241.

  However, in order to increase the cross-sectional area of the cord, it is necessary to increase the number of filaments constituting the cord, which increases the weight of the cord. That is, when a cord with increased weight is used for tire reinforcement, the weight of the tire naturally increases. When this tire is used in a vehicle, fuel efficiency is adversely affected.

  Therefore, the breaking strength of the cord is improved without increasing the cord weight by increasing the strength of the filament constituting the cord. For example, measures are taken such as adjusting the component composition of the filament constituting the cord and adjusting the processing rate when the filament is drawn.

  However, a cord with a double twist structure has a problem that when a large impact is applied, a specific filament breaks first, that is, a so-called preceding break occurs. This pre-breaking is a phenomenon that occurs mainly at the contact point where filaments where tightening stress concentrates intersect. That is, when the cord receives a large external force, the strands constituting the cord are further twisted and the filaments constituting the strand are subjected to a clamping pressure due to the twisting. Since this tightening pressure is concentrated at the contact point where the filaments intersect, the filament cannot withstand that pressure and breaks in advance.

Therefore, Patent Document 1 proposes a means for suppressing the breakage of the cord by covering the surface of the core strand in the cord composed of the core strand and the sheath strand and preventing the contact between the core strand and the sheath strand. Has been.
International Publication No. 2002/044464 Pamphlet

  Here, FIG. 1 shows a cross-sectional view orthogonal to the axial direction of a 7 × (3 + 9) structure cord as an example of a double twisted structure cord disclosed in Patent Document 1. The cord in the cross-sectional view shown in FIG. 1 is the same as the core strand 3 around one core strand 3 in which nine filaments serving as the sheath 2 are twisted around the core 1 consisting of three filaments. Six sheath strands 4 having a structure are further twisted together.

  In Patent Document 1, in the cord cross-sectional view of FIG. 1, by providing a polymer layer 5 between the core strand 3 and the sheath strand 4, the filaments constituting the sheath 2 of the core strand 3 and the sheath strand 4 The contact at the intersection is prevented and the breakage of the cord is suppressed.

  However, the provision of the polymer layer 5 means that the periphery of the core strand 3 is covered with the polymer layer 5 and the path to the inside of the core strand 3 is blocked. That is, when a tire is manufactured using this cord for a tire, the rubber does not penetrate into the core strand 3 during the vulcanization. Therefore, the core strand 3 after the vulcanization process has a gap between the core 1 and the sheath 2. Thus, the gap 6 extending in the axial direction of the cord 7 is formed. Therefore, contact between the filaments constituting the core strand 3 cannot be avoided, and the tightening stress generated at the contact point where the filaments intersect inside the core strand 3 is not relaxed, and the suppression of the preceding breakage is insufficient. End up.

  Further, when such a cord 7 is applied to a tire, the presence of the gap 6 inside the core strand 3 causes the following disadvantages. In other words, when the tire is used in the extremely severe environment described above, the tire may be damaged such that it reaches the inside of the core strand, and moisture that has entered from the injury reaches the void 6 inside the core strand. In the core strand 3, the filament corrodes. Furthermore, since moisture that has entered the gap 6 inside the core strand 3 propagates in the axial direction of the cord 7, the filament inside the core strand corrodes along the axial direction of the cord 7, and this corroded area is the cord. It will expand toward the 7-axis direction. As a result, the strength of the filament is reduced, and eventually the filament is broken.

  In order to suppress the preceding breakage due to the contact between the filaments described above and the breakage of the filament due to the corrosion described above, the gap 6 inside the core strand 3 is filled with a filler such as rubber or polymer, It is necessary to prevent moisture from entering. However, in order to fill the void 6 after providing the polymer layer, in the process of manufacturing the core strand 3, it is necessary to perform extrusion multiple times from the first step of manufacturing the core 1. For this reason, the number of steps until the core strand 3 is completed increases, resulting in an increase in cost.

  Therefore, the present invention suppresses the breakage due to the preceding breakage and corrosion of the filament by allowing the rubber to sufficiently infiltrate the core strand covered with the polymer layer, particularly in the cord of the double twist structure composed of the core strand and the sheath strand. The purpose is to propose a code structure to be executed.

  In view of the above-described problems, the inventors have intensively studied measures for suppressing breakage due to preceding breakage and corrosion of the filament in the core strand coated with the polymer layer, and as a result, by providing an opening in the polymer layer. The inventors have found that rubber can be sufficiently infiltrated into the core strand during vulcanization of tire manufacture, and have completed the present invention.

That is, the gist configuration of the present invention is as follows.
(1) A cord in which a plurality of sheath strands composed of a plurality of filaments are twisted around a core strand composed of a plurality of filaments, and a polymer layer is disposed between the core strands and the sheath strands A rubber article reinforcing cord provided, wherein the polymer layer has an opening in which the core strand is partially exposed.

(2) The core strand and the sheath strand are strands formed by twisting at least one layer of a sheath of a plurality of filaments around a core of one or a plurality of filaments, and at least the core strand includes each layer. (1) wherein the diameter of the constituting filaments is at least the same in the layer, and the number of filaments in the layer is 1 to 3 less than the maximum number of filaments that can be arranged in the layer. The cord for reinforcing rubber articles described in 1.

(3) The cord for reinforcing a rubber article according to (1) or (2), wherein the opening has a long hole shape extending continuously or discontinuously in the axial direction of the core strand.

(4) In any one of the above (1) to (3), the opening is a long hole extending continuously or discontinuously in an oblique direction with respect to the axial direction of the core strand. The cord for reinforcing rubber articles as described.

(5) The rubber article reinforcing cord according to any one of (1) to (4), wherein the opening is cylindrical or curved along the circumference of the core strand.

(6) The cord for reinforcing a rubber article according to any one of (1) to (5), wherein the polymer layer is made of a thermoplastic polymer.

(7) The cord for reinforcing a rubber article according to (6), wherein the thermoplastic polymer is composed of at least one of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

(8) The cord for reinforcing a rubber article according to the above (1) to (7), wherein the polymer layer is formed by extrusion molding.

(9) The rubber article reinforcing cord according to any one of (1) to (8), wherein the polymer layer is formed by winding a band-shaped polymer material around the core strand.

(10) The cord for reinforcing rubber articles according to any one of (1) to (9) above, wherein the filament has a diameter of 0.15 to 0.40 mm.

(11) A tire having a carcass extending in a toroidal shape between a pair of bead portions, and having at least one belt on the outer side in the tire radial direction of the carcass, and one or both of the carcass and the belt A tire comprising the rubber article reinforcing cord according to any one of (1) to (10) above.

(12) The tire according to (11), wherein the core strand constituting the cord is filled with rubber.

  According to the present invention, by providing a polymer layer between a core strand and a sheath strand constituting a double twist structure, contact between the core strand and the sheath strand is prevented, and stress due to a large external load is alleviated. be able to. As a result, it is possible to suppress the preceding breakage of the filament and to suppress a decrease in the breaking strength of the entire cord. Moreover, by providing an opening in the polymer layer where the core strand is partially exposed, for example, in the vulcanization process during tire manufacture, rubber is infiltrated into the core strand from the opening, and corrosion inside the core strand is caused. By avoiding the intrusion of moisture, which is the cause of the above, it is possible to suppress a decrease in the strength of the filament due to corrosion. As a result, it is possible to provide a cord having an excellent breaking strength and a lightweight and durable tire using the cord.

First, FIG. 2 shows a cross-sectional view perpendicular to the cord axis direction of a cord having a double twist structure according to the present invention.
The cord 17 shown in FIG. 2 twists eight filaments that become the first sheath 9 around the core 8 that consists of three filaments, and then twists 13 filaments around the first sheath 9 In addition, six sheath strands 13 having the same structure as the core strand 12 in the illustrated example are twisted around the core strand 12 including the second sheath 10. The cord structure is not particularly limited as long as it is a double twist structure. For example, the cord described above employs a three-layered strand, but may employ a two-layered or four-layered or more structured strand. The cord 17 is provided with the wrapping filament 16 in order to prevent the strand shape from being unraveled and breaking the cord shape when the cord is cut to the required length during tire manufacture. Even if not, the effect in the present invention can be obtained.

  Here, it is important to first provide the polymer layer 14 between the core strand 12 and the sheath strand 13 constituting the cord.

That is, by providing the polymer layer 14 between the core strand 12 and the sheath strand 13, it is avoided that the filaments constituting the second sheath 10 of the core strand 12 and the sheath strand 13 are in direct contact with each other. Breakage of the filaments constituting 10 can be suppressed. As a result, it is possible to suppress a decrease in the effective cross-sectional area that contributes to the breaking strength of the cord.

  Here, the polymer layer preferably has a thickness of 0.02 to 0.5 mm. In other words, if it is thinner than 0.02 mm, the expected cushioning effect of the polymer layer is reduced, and when a tensile load is applied to the entire cord, tightening becomes stronger and the tendency for the filaments to come into contact with each other increases, leading to a preceding break. It becomes difficult to obtain the suppressing effect. In order not to unnecessarily increase the outer diameter of the cord, the thickness of the polymer layer is preferably 0.5 mm or less. Here, for the thickness of the polymer layer, in the cross section orthogonal to the axial direction of the cord cut out so that the shape does not collapse, select the closest filament interval between the inner and outer filaments across the polymer layer, This interval was measured for five or more different cross sections, and the results were averaged.

Incidentally, it is conceivable to improve the breaking strength of the cord 17 by improving the tensile strength of the filament without providing the polymer layer 14. However, as the tensile strength of the filament is improved, the ductility is lowered, so that the preceding breakage of the filament is more likely to occur. That is, at the contact portion between filaments where the tightening stress is concentrated inside the cord, this tightening stress becomes a shear stress and breaks the filament. It is easy to produce.

  Furthermore, it is important to provide the polymer layer 14 with an opening 15 through which the core strand 12 is partially exposed. In the illustrated example, the opening 15 is formed in the shape of a long hole extending in the axial direction of the core strand 12, so that rubber can enter the core strand 12 from the opening 15 during vulcanization in the tire manufacturing process. Become. The rubber that has entered the core strand 12 relieves the tightening stress generated between the filaments constituting the core strand 12, and as a result, the preceding breakage of the filament can be suppressed. Further, by suppressing the preceding breakage of the filament, a decrease in the effective sectional area of the cord is avoided, and as a result, a decrease in the cord breaking strength can be prevented.

  In addition, the rubber that has entered the core strand 12 from the opening 15 can suppress the propagation of corrosion and suppress the decrease in the breaking strength of the cord 17. In other words, if the core strand 12 is filled with rubber, it prevents moisture from entering the core strand 12, thereby avoiding corrosion inside the core strand 12 and suppressing filament breakage due to corrosion. Therefore, it is possible to suppress a decrease in the effective area that contributes to the breaking strength of the cord 17. In addition, the vulcanized rubber filled in the core strand 12 can prevent moisture that causes corrosion from spreading to the entire cord, and can suppress a decrease in strength of the cord 17. Therefore, a decrease in strength of the entire tire can be suppressed.

  Of the core strands 12 and the sheath strands 13, at least the core strands 12 have a core 8, a first sheath 9, and a second sheath 10 that constitute each strand in order to further enhance the penetration of rubber into the core strands 12. In each layer, the filaments constituting each layer have the same diameter, and the number of filaments in each layer is 1 to 3 less than the maximum number of filaments that can be placed in each layer. Is preferred.

  Here, the maximum number of filaments that can be arranged in each layer is that when the total of the gaps between the filaments constituting each layer is less than the diameter of one filament in the cross section orthogonal to the cord axis direction. It means the number of filaments.

  The reason why the diameter of the filaments is preferably the same in each layer is that, if the filament diameters are different, the strand shape is uneven, and the filaments arranged in the protrusions are in contact with each other between the strands. This is because when the contact is made, the stress concentration becomes particularly significant, leading to a preceding fracture.

  Further, the reason why the number of filaments constituting each layer is one less than the maximum number is to make the rubber penetrate more sufficiently into the interior of each strand by forming a gap. In addition, if the number of filaments excluded from each layer exceeds 3, the total cross-sectional area of the filament occupying in the cord is reduced, and therefore the tendency for the breaking strength of the cord to decrease is increased.

  In the example shown in FIG. 2, the opening 15 has a long hole shape extending in the axial direction of the core strand. However, the shape of the opening 15 is not limited to the example shown in FIG. The shape shown in FIG. 13 can also be applied. In short, it is only necessary to secure a rubber infiltration path during vulcanization. That is, the opening 15 shown in FIG. 3 is a modification of the opening 15 of FIG. 2, and a plurality of the long hole-like openings 15 are arranged at intervals in the core strand axial direction and shifted in the circumferential direction. This is an example. Also, the opening 15 shown in FIG. 4 has a long hole shape extending continuously in an oblique direction with respect to the core strand axial direction, and the opening 15 shown in FIG. The opening 15 shown in FIG. 6 is an example of a long hole extending discontinuously in an oblique direction with respect to the axial direction of the core strand. Furthermore, the opening 15 shown in FIG. 7 is a cylindrical example along the circumference of the core strand, and the opening 15 shown in FIG. 8 is an example of a curved surface along the circumference of the core strand. The opening 15 shown in FIGS. 9 to 13 is an example provided in a direction opposite to the inclination direction of the opening 15 shown in FIG.

  Here, in order to allow the rubber to enter the core strand, the width of the opening 15 along the circumference of the core strand in the cross section perpendicular to the axial direction of the cord has a width of the filament forming the outermost layer of the core strand. The diameter is preferably 1.5 times or more of the diameter.

  The polymer layer 14 is preferably a thermoplastic polymer. This is because, in general, cords are often produced in large quantities in a dedicated factory separate from the tire factory.In this case, the storage period may be required for several days from the manufacture of the cord to the tire product. This is because it is difficult to adversely affect the plating of the cord surface (which has an adhesive action with rubber). Furthermore, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyamide (PA), polyester (PES), polypropylene (PP), polyvinyl chloride (PVC), polytetrafluoroethylene ( It is preferable to use PTFE), polyethylene (PE), a copolymer thereof, a blend material, or the like.

  Here, the polymer layer 14 is preferably formed by extrusion. That is, by forming the polymer layer 14 by extrusion, there is an advantageous effect that the polymer material can be thinly and uniformly coated in the circumferential direction of the core strand.

The polymer layer 14 covering the core strand 12 is preferably formed by winding a band-shaped polymer material around the core strand 12. For example, the polymer layer 14 can be formed by a method of spirally winding a band-shaped polymer material around the core strand 12 or wrapping the core strand 12. That is, there is an advantageous effect that the coating of the polymer material in the cord axis direction can be made uniform by controlling the thickness of the polymer layer by the thickness of the band-shaped polymer material.

  Here, the opening 15 of the polymer layer 14 can be formed at the time of extrusion molding. For example, it can be provided by devising the shape of the die used for extrusion molding, applying periodic vibration to the die, or kneading gas in the polymer material. Further, the opening 15 can also be provided by processing such as scratching after extrusion.

  For example, in the extrusion molding, the opening 15 is preferably formed using a die having a guide hole 18 for passing the core strand shown in FIG. 15 and a C-shaped hole 19 for extruding the polymer material around the guide hole 18. . That is, the opening 15 can be formed by passing the core strand through the guide hole 18 and extruding the polymer material through the C-shaped hole 19. In addition, in order to form the opening 15 by periodic vibration, in the extrusion molding in which the core strand and the polymer are extruded simultaneously from a single hole, the portion where the core strand 12 and the base come into contact with each other by applying the vibration If generated, the polymer material at the contact portion is interrupted to form the opening 15. In addition, in order to form the opening 15 by the gas kneaded with the polymer material, bubbles having a diameter larger than the thickness of the polymer layer 14 are dispersed and contained when the polymer material is kneaded, and the gas passes through the die. When doing so, the bubbles break and become the openings 15. If larger bubbles are kneaded in the polymer material, when the bubbles are supplied to the die, the supply of the polymer material is interrupted by covering the entire periphery of the core strand, resulting in a larger opening 15.

Further, when the polymer layer 14 is formed by spirally winding the band-shaped polymer material around the core strand 12 or by wrapping the core strand 12, the band-shaped polymer layer end and the other end It is also possible to provide the opening 15 by a method such as opening a gap therebetween.

  And it is preferable that the diameter of the filament which comprises each of the core strand 12 and the sheath strand 13 is 0.15-0.40 mm. That is, when the filament diameter is thinner than 0.15 mm, the filament is likely to break earlier due to the twisted structure of the double twist structure, and the strength improvement effect by the polymer layer 14 is reduced. Further, when the filament diameter is larger than 0.40 mm, it tends to be inferior in fatigue resistance and difficult to use as a tire reinforcing material.

  Furthermore, the tensile strength of the filament is preferably 2700-4200 MPa. That is, when the tensile strength of the filament is less than 2700 MPa, when the cord 17 is formed using this filament, the breaking strength itself of the cord 17 is at a low level. Further, the cord 17 has a sufficient ductility and is unlikely to cause a preceding breakage of the filament due to the twisted structure of the double twist structure, so that the effect of improving the strength by providing the polymer layer becomes small.

  In addition, filaments exceeding 4200MPa tend to be susceptible to ductility degradation as the tensile strength increases. However, it is difficult to obtain a powerful improvement effect.

Now, the above cord is applied to a tire carcass or belt, a ply formed by embedding a plurality of cords in parallel with each other at a predetermined interval and embedded in a rubber sheet. As a tire structure, In particular, it may conform to a conventional tire to be mounted on a construction vehicle. For example, the tire structure shown in FIG. 16 is advantageously adapted. In the figure, reference numeral 20 denotes a bead core, 21 denotes a carcass wound around the bead core 20 from the inside to the outside of the tire, 22 denotes a belt having at least a two-layer structure disposed on the carcass 21, and 23 denotes a crown of the carcass 21. It is a tread arranged in the section.

  In the cord applied to the reinforcement of the tire belt described above, the inside of the core strand constituting the cord needs to be filled with rubber. That is, as described above, the preceding breakage of the filaments constituting the core strand is suppressed, and further, the propagation of corrosion spreading over the entire cord is avoided, and as a result, a decrease in tire strength can be suppressed. Further, by filling the opening with rubber at the time of vulcanization, contact between the filaments constituting the core sheath and the second sheath of the sheath strand constituting the cord can be further alleviated. As a result, the stress due to the load received from the outside is further relaxed, and the cord has a higher strength. Furthermore, by applying this cord to the tire, a lightweight and durable tire can be provided.

  Under the specifications shown in Table 1, a cord based on the double twist structure shown in FIG. 2 was produced. Furthermore, the cord was subjected to vulcanization pressure and temperature assuming the vulcanization step of the tire manufacturing process, and a vulcanized sample was produced. Then, an end portion of the vulcanized sample was cut, and a corrosion test was performed in which the exposed cord surface was left in salt water. In this corrosion test, before and after corrosion of the vulcanized sample, a tensile test based on JIS G 3510 and JIS Z 2241 was applied to the vulcanized sample, the breaking strength of the vulcanized sample was measured, and the strength reduction rate was investigated. The results are shown in Table 2.

In measuring the strength reduction rate, first, using each vulcanized sample before and after corrosion in the corrosion test, in the tensile test described above, the cord taken out from the vulcanized sample and the breaking strength of the filament constituting the cord Was measured. Then, using the measured value, obtain the strength display rate (%) defined by the following formula (1), and calculate the strength reduction rate by comparing the strength display rate (%) of the vulcanized sample before and after corrosion. did. The results are shown in Table 2.
Strength display rate (%) = Cord breaking strength / Sum of breaking strength of filament before corrosion
× 100 ---- (1)

  In Table 2 of the present invention, when the conventional example and the invention example are compared, it can be seen that the corrosion rust is suppressed in the invention example. In addition, in the cord after corrosion, an improvement in the strength reduction rate is also observed. Further, in the cord before corrosion, the strength display rate is slightly improved, and the effect obtained by providing an opening in the polymer layer is noticeable.

  FIG. 5 is an example in which a polymer layer is covered between a core strand and a sheath strand constituting a 7 × (3 + 8) structure cord, and openings are provided at a plurality of locations. As in such an example, it is possible to provide not only one place but also a plurality of openings, and since the rubber penetration inside the core strand is good, the same improvement effect as described above is seen. It is done.

3 is a view showing a cross section of a cord disclosed in Patent Document 1. FIG. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed the cross section of the cord of this invention or the comparative example, and the core strand three-dimensionally. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed three-dimensionally the sectional view of the cord of the present invention, and the core strand. It is the figure which showed the sectional view of the cord of the conventional example, and the core strand three-dimensionally. It is the figure which showed the cross section of a nozzle | cap | die shape. It is sectional drawing which shows a tire structure suitable for applying the cord of this invention.

Explanation of symbols

1 core
2 sheath
3 Core strand
4 Sheath strand
5 Polymer layer
6 Air gap
7 code
8 core
9 First sheath
10 Second sheath
11 3rd sheath
12 Core strand
13 Sheath strand
14 Polymer layer
15 opening
16 Wrapping filament
17 code
18 Guide hole
19 C-shaped hole
20 Beadcore
21 Carcass
22 belt
23 Tread

Claims (12)

  A cord in which a plurality of sheath strands composed of a plurality of filaments are twisted around a core strand composed of a plurality of filaments, and a polymer layer is provided between the core strand and the sheath strand, A cord for reinforcing a rubber article, wherein the polymer layer has an opening in which the core strand is partially exposed.   The core strand and the sheath strand are strands formed by twisting at least one layer of a sheath of a plurality of filaments around a core of one or a plurality of filaments, and at least the core strand is a filament constituting each layer 2. The rubber according to claim 1, wherein the diameter is at least the same in the layer, and the number of filaments in the layer is 1 to 3 less than the maximum number of filaments that can be arranged in the layer. Article reinforcement cord.   3. The rubber article reinforcing cord according to claim 1, wherein the opening has a long hole shape extending continuously or discontinuously in the axial direction of the core strand.   4. The rubber article reinforcing member according to claim 1, wherein the opening has a long hole shape extending continuously or discontinuously in an oblique direction with respect to the axial direction of the core strand. code.   5. The rubber article reinforcing cord according to claim 1, wherein the opening is cylindrical or curved along the circumference of the core strand.   6. The rubber article reinforcing cord according to claim 1, wherein the polymer layer is made of a thermoplastic polymer.   7. The rubber article reinforcing cord according to claim 6, wherein the thermoplastic polymer is made of at least one of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.   8. The rubber article reinforcing cord according to claim 1, wherein the polymer layer is formed by extrusion molding.   9. The rubber article reinforcing cord according to claim 1, wherein the polymer layer is formed by winding a band-shaped polymer material around the core strand.   10. The rubber article reinforcing cord according to claim 1, wherein the filament has a diameter of 0.15 to 0.40 mm.   A tire having a carcass extending in a toroidal shape between a pair of bead parts, and having at least one layer of belt on the outer side in the tire radial direction of the carcass, wherein one or both of the carcass and the belt are claimed. A tire comprising the rubber article reinforcing cord according to any one of 1 to 10 applied thereto.   12. The tire according to claim 11, wherein the core strand constituting the cord is filled with rubber.

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