JP2018135019A - Pneumatic tire and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire which suppresses cracking from a cord cut end of a main cord reinforcement layer without causing a problem caused by an auxiliary reinforcement layer itself, and further improves durability compared to a conventional one, and to provide a method for producing the same.SOLUTION: An auxiliary reinforcement layer 4 is arranged in the vicinity of a cord cut end of at least one layer out of a carcass ply 1 and a belt layer 3 as a main cord reinforcement layer or in the vicinity of an outer end in a tire width direction of a chafer, the auxiliary reinforcement layer is arranged at a position covering at least the adjacent cord cut end of the main cord reinforcement layer or vicinity of the outer end in the tire width direction of the chafer from inside and/or outside of a tire, and the auxiliary reinforcement layer is embedded with a core-sheath type composite fiber (C) formed of a resin material (B), in which a core part is formed of a high melting point resin (A) having a melting point of 150°C or higher and a sheath part contains an olefin polymer (D) having a melting point equal to or lower than a tire vulcanization temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pneumatic tire (hereinafter also simply referred to as “tire”) and a method for manufacturing the same.

  The cord material constituting the belt layer and the carcass ply is usually subjected to an adhesion treatment for adhering to the rubber. However, the belt layer and the carcass ply are cut to the desired dimensions after the member is manufactured, so the cut end portion This exposes the cross section of the cord without a surface coating for adhesion. Such a cord cut end that does not adhere to rubber is likely to be a starting point of a crack due to strain input during traveling. Therefore, conventionally, in a tire including a cord reinforcing layer such as a carcass ply or a belt layer, a crack progresses from a cord cut end of the cord reinforcing layer, for example, a folded end portion of the carcass ply or a width direction end portion of the belt layer. Various techniques have been studied in order to prevent tires and increase the durability of tires.

  Such a crack growth from the cut end of the cord is caused by the following mechanism. That is, at the folded end portion of the carcass ply in the bead portion, a force acts in the direction in which the carcass ply is pulled out when filling with internal pressure, while the load portion rolls, and the bead portion is bent so that repeated deformation of tension and compression in the tire radial direction occurs. And the rubber is cracked due to the rigidity step between the folded end and the surrounding rubber. Also, at the end of the belt layer, cracking occurs in the rubber due to a difference in rigidity with the surrounding rubber due to deformation during filling with internal pressure and rolling under load.

  On the other hand, a technology has been proposed in which an auxiliary reinforcing layer using rubber reinforcing fibers is provided adjacent to the cord cut end of the cord reinforcing layer. In this case, if the rigidity of the auxiliary reinforcing layer is high, the auxiliary There is a problem that the reinforcing layer itself tends to cause stress concentration and cracks are likely to occur.

  In order to prevent the auxiliary reinforcing layer from causing stress concentration with respect to this problem, the bending rigidity of the fiber member of the auxiliary reinforcing layer is set to 1/10 or less of the main cord reinforcing layer, There has been proposed a tire capable of effectively suppressing the development even if a crack occurs at the end of the belt layer or the carcass ply. In addition, as an auxiliary reinforcing layer, it has also been proposed to dispose a bi-directional elastic braided fabric having energy absorption and diffusion effects so as to extend along the carcass end region of the folded section of the ply. In this bi-directional elastic fabric, at least one fiber selected from polyamide, polyester, rayon, cotton, wool, aramid, silk and flax is used, and the elastic elongation ratio resulting from the braided structure is a characteristic of the fabric, It is disclosed that it is preferable to have at least 8% or more, and it is disclosed that a material having elongation and low rigidity is used in a braided structure.

  Further, in Patent Document 1, an auxiliary reinforcing layer is provided at the end in the width direction adjacent to at least one cord cutting end portion of one or more carcass plies and two or more belt layers as a main cord reinforcing layer. And a plurality of protrusions spaced in the tire circumferential direction on the surface of the auxiliary reinforcing layer facing the main cord reinforcing layer. A provided pneumatic radial tire is disclosed.

  On the other hand, conventionally, various kinds of organic fibers and metal materials have been studied and used as tire reinforcing materials. In addition, as a kind of organic fiber, various studies have been made so far to use a so-called core-sheath fiber as a reinforcing material, which includes a core part having a cross-sectional structure at the center and a sheath part covering the outer periphery thereof. For example, in Patent Document 2, a resin selected from at least one of polyester, polyamide, polyvinyl alcohol, polyacrylonitrile, rayon, and a heterocyclic polymer is used as a core component, and a thermoplastic resin that can be thermally fused to rubber is used as a sheath component. A cord / rubber composite is disclosed in which a cord composed of a core-sheath fiber is embedded in unvulcanized rubber and vulcanized and integrated. Further, the applicant of the present application also disclosed in Patent Document 3 that the core portion is made of a high melting point polyolefin resin (A) having a melting point of 150 ° C. or higher and the sheath portion has a melting point of 80 ° C. or higher and lower than 150 ° C. at least radially outside the bead core. A tire in which a reinforcing layer using a reinforcing material made of a core-sheath type composite fiber (C) made of a low-melting-point polyolefin resin (B) is provided.

JP-A-2005-145318 (Claims etc.) Japanese Patent Laid-Open No. 10-6406 (claims, etc.) International Publication No. 2015/156405

  However, even if the auxiliary reinforcing layer is embedded in the rubber, even if the cord material is subjected to a surface treatment for adhesion to the rubber, the cord material must be placed in the rubber with the desired dimensions. Since cutting is performed, there is no surface coating for bonding at the cut end. Therefore, the conventional tires still have a problem that cracks are likely to occur from the end surface of the cord material of the auxiliary reinforcing layer when a strain exceeding the limit is applied as a load after adhesion to the rubber.

Therefore, the purpose of the present invention is to improve the adhesion between the rubber and the fiber for the auxiliary reinforcing layer disposed adjacent to the cord cut end of the main cord reinforcing layer such as a tire belt layer or a carcass ply, A pneumatic tire and a method for manufacturing the same, in which the occurrence of cracks from the cut end of the main cord reinforcing layer is suppressed without causing problems due to the auxiliary reinforcing layer itself, and the durability is further improved as compared with the conventional one. It is to provide.
In the present invention, the main cord reinforcing layer means that a tire made of only a rubber material has low strength, particularly tensile strength, and is disposed according to a load at each portion of the tire. The carcass ply, belt layer, chafer These are known cord reinforcement layers such as inserts, flippers, and chippers, and the cord layers made of these fiber materials can reinforce the strength of the rubber tire and retain its shape.
As an example of these main cord reinforcing layers, the carcass ply has its side portion wound around the bead core and disposed on the toroidal so as to bear a strain such as expansion due to internal pressure and maintain the shape. Further, the belt layer is disposed on the outer side in the radial direction of the crown portion of the carcass ply so as to bear the deformation of the protrusion of the tread portion at the time of high speed running and give a wrinkle effect. The chafer is arranged on the outer side in the tire width direction of the bead part of the carcass ply and gives an effect of suppressing the deformation that the bead part collapses due to the load under high load, and according to the load at each place arranged on the tire The required strength plays a role of supplementing the strength of the carcass cord.
Further, in the present invention, the auxiliary reinforcing layer is a cord reinforcing layer disposed in each part of the tire, adjacent to a main cord reinforcing layer such as a carcass ply, a belt layer, a chafer, an insert, a flipper, and a chipper. A reinforcing layer disposed for the purpose of supplementing functions such as strength and strain resistance. Therefore, in the present invention, the reinforcing layer disposed adjacent to the carcass ply, belt layer, chafer, insert, flipper, and chipper is used when the main cord reinforcing layer adjacent to the auxiliary reinforcing layer of the present invention is a chafer. It is written as “Auxiliary reinforcement layer of chafer”. Similarly, the auxiliary reinforcing layer of the present invention adjacent to the carcass ply is referred to as “carcass ply auxiliary reinforcing layer”.
In addition, the reinforcing layer in which the auxiliary reinforcing layer of the present invention is disposed adjacently is referred to as a main cord reinforcing layer relative to the auxiliary reinforcing layer. That is, when the auxiliary reinforcing layer of the present invention is adjacent to the carcass ply, the main cord reinforcing layer is used as the carcass ply. When the auxiliary reinforcing layer is disposed adjacent to the belt layer or chafer, the belt layer or chafer is used as the main cord reinforcing layer.

  As described above, when the auxiliary reinforcing layer is used to prevent the occurrence of cracks from the cord cut ends of the main cord reinforcing layer, it is necessary to consider the occurrence of cracks from the cord cut ends of the auxiliary reinforcing layer itself. is there. That is, even if the auxiliary reinforcing layer is arranged to protect the cord cut end of the main cord reinforcing layer, the end portion is similarly cracked in a large strain area where the cord cut end of the main cord reinforcing layer cracks. When the cord end of the auxiliary reinforcing layer that is easy to be disposed is disposed, the cord end of the auxiliary reinforcing layer is also the same cord cut end, and thus cracks are generated due to strain. For this reason, the auxiliary reinforcing layer needs to have a relatively long width, and the cord ends need to be arranged in a region having a small distortion.However, in such an auxiliary reinforcing layer, in a tire whose weight has been reduced in recent years, Since the rubber between the cords is reduced due to the weight reduction, it is becoming difficult to dispose the cord end in a region where the distortion is small. Also, if the auxiliary reinforcing layer has a longer width, the tire weight increases and the tire becomes lighter, which is contrary to the recent trend of reducing the rolling resistance of the tire by reducing the rubber with a large hysteresis loss. Therefore, it can be said that a solution using an auxiliary reinforcing layer having a cord end in a large strain region is more preferable.

  As described in Patent Document 3, the present inventors apply a core-sheath type composite fiber whose sheath resin material has a melting point of 80 ° C. or higher and lower than 150 ° C. to a reinforcing cord of a tire, and takes it out from the tire after manufacturing. As a result of observing the composite fiber in the composite of the rubber and the composite fiber in the cross-sectional direction, the sheath resin material becomes a melt due to heat during vulcanization, and the fluidized resin forms a void between the rubber and the composite fiber. It has been found that, when wet and buried, strong adhesion can be obtained by welding. As a result of continuous studies, the present inventors have found that in the reinforcing cord, when the core-sheath composite fiber is vulcanized, the sheath resin material that is melted and fluidized by heat is only in the cross-sectional direction of the reinforcing cord. The gap between the rubber and the end of the reinforcing cord is also wetted and filled, and the sheath resin covered with the melted high melting point resin of the core is fused between the rubber and the core cross section. In order to do so, the inventors have found an unprecedented knowledge that fusion can be obtained even in the cross section of the cut end of the reinforcing cord.

  From such a viewpoint, as a result of further investigations, the present inventors have found that a specific core-sheath type composite fiber (hereinafter simply referred to as “core-sheath fiber”) is used as an auxiliary reinforcing layer covering the cord cut end of the main cord reinforcing layer. The above-mentioned problems can be solved by applying the above), and the present invention has been completed. According to the present invention, in the auxiliary reinforcing layer used in the portion where the crack propagates from the gap of the unbonded portion of the cord cut end, the cord cut end is prevented so that the crack from the cord cut end of the auxiliary reinforcing layer itself does not progress. By using the cord material of the present invention whose cross section is fused, it is possible to provide a member of an auxiliary reinforcing layer in which cracks are unlikely to occur.

That is, the pneumatic tire according to the present invention has one or more layers of carcass plies in which cutting cords are arranged in parallel, the side portions thereof are wound around the bead core and disposed on the toroid, and the crown portion of the carcass ply A pneumatic tire in which one or more belt layers in which cutting cords are arranged in parallel are arranged on the outer side in the tire radial direction,
As a main cord reinforcing layer, near the cord cutting end of at least one of the carcass ply and the belt layer, or near the outer end in the tire width direction of the chafer disposed outside the carcass ply in the bead portion. An auxiliary reinforcing layer is disposed adjacently, and the auxiliary reinforcing layer is at least the cord cut end of the adjacent main cord reinforcing layer or the vicinity of the outer end in the tire width direction of the chafer inside the tire. And / or disposed at a position covering from the outside,
Resin material (B) including an olefin polymer (D) having a core portion made of a high melting point resin (A) having a melting point of 150 ° C. or higher and a sheath portion having a melting point not higher than the tire vulcanization temperature. A core-sheath type composite fiber (C) made of is embedded.

  In the tire of the present invention, it is preferable that a distance in a thickness direction of the main cord reinforcing layer between the main cord reinforcing layer and the auxiliary reinforcing layer is 3 mm or less. In the tire of the present invention, the olefin polymer (D) is a propylene-α olefin copolymer (H), a propylene-nonconjugated diene copolymer (I), an unsaturated carboxylic acid or an anhydride thereof. One or more components selected from the group consisting of an ionomer (J) having a degree of neutralization with a metal salt of an olefin copolymer containing a product monomer of 20% or more, and an olefin homopolymer (K) It is preferable to comprise.

  Furthermore, in the tire of the present invention, the resin material (B) includes a styrene elastomer (L) containing a single molecular chain in which the olefin polymer (D) and a styrene monomer are mainly continuously arranged. ), A vulcanization accelerator (M), a vulcanization accelerator (N), and one or more selected from fillers (O). Furthermore, the propylene-α olefin copolymer (H) is preferably a propylene-ethylene random copolymer and / or a propylene-ethylene-butene random copolymer.

  Furthermore, in the tire of the present invention, the ionomer (J) is preferably an ionomer of an ethylene / ethylenically unsaturated carboxylic acid copolymer, and the olefin homopolymer (K) is a polyethylene polymer. And / or a polypropylene polymer. Furthermore, it is preferable that the styrenic elastomer (L) contains a styrenic block copolymer, a hydrogenated product thereof, or a modified product thereof.

  Furthermore, in the tire of the present invention, the styrene elastomer (L) is preferably a styrene-butylene-butadiene-styrene copolymer, and the high melting point resin (A) has a melting point of 150 ° C. or higher. It is preferable to include a polymer selected from polyolefin resin (P), polyester resin (Q), and polyamide resin (R). Furthermore, the fineness of the composite fiber (C) is preferably 50 to 4000 dtex, more preferably 500 to 1200 dtex, and the number of driving of the composite fiber (C) is 5 to 65 fibers / 50 mm. It is preferable.

The tire manufacturing method of the present invention is a method for manufacturing the pneumatic tire of the present invention,
The composite fiber (C) is arranged in parallel and covered with a rubber to produce a sheet-like rubber-fiber composite, and a composite is prepared by cutting the rubber-fiber composite obtained. In the cutting step of obtaining a body strip and in the primary molding of a green tire, the obtained composite strip is adjacent to the vicinity of the cord cutting end of the carcass ply, which is a carcass folded portion in the cylindrical molded body of the carcass ply Then, an affixing step for affixing at least the cord cut end to cover the entire circumference from the outer side of the tire, and an expansion step for expanding the composite strip together with the carcass ply to a predetermined outer diameter in the secondary molding of the green tire It is characterized by including these.

  In the production method of the present invention, for example, a sheet-like rubber-fiber composite having a thickness of 0.5 to 1.5 mm is prepared in the composite preparation step, and the rubber-fiber composite obtained in the cutting step is prepared. The body can be cut at 20-1000 mm intervals.

  According to the present invention, without causing problems due to the auxiliary reinforcing layer itself, the occurrence of cracks from the cord cut end of the main cord reinforcing layer is suppressed, and the pneumatic in which durability is further improved as compared with the conventional case. A tire and a manufacturing method thereof can be realized.

It is a width direction one side sectional view showing an example of the pneumatic tire of the present invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction one side sectional view showing other examples of the pneumatic tire of the present invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is a width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention. It is explanatory drawing which shows the behavior at the time of vulcanization | cure in the cut end part of the rubber-fiber composite using the composite fiber which concerns on this invention. It is explanatory drawing which shows the behavior at the time of vulcanization | cure in the cut end part of the rubber-fiber composite using the composite fiber which concerns on this invention. It is explanatory drawing which shows the behavior at the time of vulcanization | cure in the cut end part of the rubber-fiber composite using the composite fiber which concerns on this invention. It is explanatory drawing which shows the behavior at the time of vulcanization | cure in the cut end part of the rubber-fiber composite using the composite fiber which concerns on this invention. It is a fluorescence-microscope photograph figure which shows the longitudinal direction edge part of the rubber-fiber composite using the composite fiber which concerns on this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, the width direction one side sectional view which shows an example of the pneumatic tire of this invention is shown. The illustrated pneumatic tire 10 of the present invention has one or more layers, for example, 1-3 layers, in the illustrated example, one layer of carcass ply 1 and one or more layers, for example, 2-6 layers, in the illustrated example, two layers. The carcass ply 1 and the belt layer 3 are each formed by arranging cutting cords in parallel. Moreover, the code | symbol CL in a figure means a tire equator surface.

  As shown in the figure, in the tire of the present invention, the carcass ply 1 is disposed in a toroidal shape with its side portion wound around the bead core 2, and the carcass ply 1 has a belt on the outer side in the radial direction of the crown portion of the tire. Layer 3 is provided.

  Further, in the tire according to the present invention, a chafer disposed in the vicinity of at least one cord cut end of the carcass ply 1 and the belt layer 3 as the main cord reinforcing layer or outside the carcass ply in the bead portion. The auxiliary reinforcing layer 4 is disposed adjacent to the vicinity of the outer end portion in the tire width direction. The auxiliary reinforcing layer 4 is disposed at a position covering at least the cord cutting end of the adjacent main cord reinforcing layer or the vicinity of the outer end of the chafer in the tire width direction from the inside and / or outside of the tire. For example, in the example shown in FIG. 1, the auxiliary reinforcing layer 4 has the cord cut end 1 a adjacent to the cord cut end 1 a of the folded end portion of the carcass ply 1 that is wound around the bead core 2. In a position covering from the tire outer side, the carcass ply 1 is disposed so as to extend both inside and outside in the tire radial direction from the cord cut end 1a.

  Here, in the present invention, “near the cord cut end” of the main cord reinforcing layer indicates a cord region including the cord cut end, and the width of the region is not particularly limited, but the cord section is preferably within 3 mm from the cord cut end. In particular, it is preferable to include a cord section within 5 mm, more preferably within 8 mm from the cord cutting end. That is, the length D of the reinforcing material extending along the vicinity of the cord cutting end is preferably 3 mm or more, particularly 5 mm, and more preferably 8 mm or more. This length D is measured along the extending direction of the auxiliary reinforcing layer. The reason for this is that when the auxiliary reinforcing layer made of the conventional cord is arranged in the main cord reinforcing layer, if the extension length D is less than 8 mm, it is a strain region in which a crack at the cord end of the main cord reinforcing layer occurs. For this reason, even in the auxiliary reinforcing layer, cracks are likely to occur at the cut end of the conventional cord. Further, if the length D of the reinforcing material is less than 5 mm, the gap on the cord cutting end face of the main cord reinforcing layer and the gap on the end face of the auxiliary reinforcing layer are close to each other, so that there is a crack between the gaps and early. It is because it becomes easy to break down. Furthermore, if the length D of the reinforcing material is less than 3 mm, the cord end positions may be the same due to variations in arrangement during manufacture. Further, “adjacent” in the vicinity of the cord cut end of the main cord reinforcing layer means that the portion where the main cord reinforcing layer and the auxiliary reinforcing layer are parallel, between the main cord reinforcing layer and the auxiliary reinforcing layer, It means that the distance in the thickness direction of the main cord reinforcing layer is within 3 mm, preferably within 1 mm. Note that the auxiliary reinforcing layer that extends from the cord cut end of the main cord reinforcing layer to the opposite side of the cord section of the main cord reinforcing layer does not necessarily mean to be arranged in parallel with the cord. When the length D of the reinforcing material extending along the vicinity of the cord cut end is less than 3 mm, the effect of burdening the stress that peels the cord end portion on the auxiliary reinforcing layer is not preferable. In addition, if the distance between the cord and the auxiliary reinforcing layer extending along the vicinity of the cord cut end exceeds 3 mm, the effect of burdening the cord end portion with the auxiliary reinforcing layer is reduced, which is not preferable.

  In the tire according to the present invention, the auxiliary reinforcing layer 4 is disposed in the vicinity of the cord cut end 1a of the folded end portion of the carcass ply 1 so that the folded end of the carcass ply 1 is pushed up from the rim flange during load rolling. Concentration of shear strain along the portion can be suppressed, and generation of cracks due to the rigidity step of the carcass ply 1 can be suppressed. Moreover, since the cord cut end of the auxiliary reinforcing layer 4 according to the present invention is fused with rubber as will be described later, the occurrence of cracks due to the cord cut end of the reinforcing fiber layer 4 can also be suppressed. Therefore, according to the present invention, without causing a problem due to the auxiliary reinforcing layer 4 itself, a crack from the cord cut end of the main cord reinforcing layer, or a crack from between the main cord reinforcing layer and the auxiliary reinforcing layer. It is possible to achieve a tire that suppresses the occurrence and progress of the occurrence, improves the durability, and further extends the life. Further, by providing an auxiliary reinforcing layer in the vicinity of the outer end portion in the tire width direction of the chafer, occurrence of cracks due to the outer end portion in the tire width direction of the chafer can be suppressed.

  Furthermore, as will be described later, the composite fiber (C) used for the auxiliary reinforcing layer 4 has a cord rigidity that can contribute to the durability improvement of the present invention at a normal tire use temperature, and at a high temperature. Since the cord rigidity or creep property under load is flexible, when an auxiliary reinforcing layer is disposed adjacent to the cord cut end portion of the main cord reinforcing layer at the time of manufacturing such as a vulcanization process in tire processing, for example, In order to prevent deformation when the green tire is pressed against the mold and vulcanized, the auxiliary reinforcement layer does not stretch and the cord cut end portion of the main cord reinforcement layer is bent. This is preferable because the disorder of the arrangement of the cords in the local area where the layer and the auxiliary reinforcing layer are adjacent to each other is reduced, and the fluctuation of the property due to the irregular shape of the tire reinforcing layer is reduced

The auxiliary reinforcing layer 4 according to the present invention is a resin containing an olefin polymer (D) having a core part made of a high melting point resin (A) having a melting point of 150 ° C. or more and a sheath part having a melting point not higher than the tire vulcanization temperature. The core-sheath type composite fiber (C) made of the material (B) is embedded. Here, the “tire vulcanization temperature” is not particularly limited, but generally means an industrial tire vulcanization temperature of 160 ° C. or lower. In addition, since a tire with a heavy weight is vulcanized for a long time at about 145 ° C. so that only the tire surface is over-vulcanized and the tire is not unvulcanized, it is more preferably 145 ° C. or lower.
Hereinafter, this composite fiber (C) will be described.

  In the core-sheath type composite fiber (C) used in the present invention, the resin material (B) constituting the sheath part includes an olefin polymer (D) having a melting point equal to or lower than the temperature at the time of tire vulcanization. When applied to the reinforcement use of rubber articles, it has the merit that it can be directly adhered by heat fusion with rubber by heating during vulcanization. That is, the core-sheath fiber according to the present invention is embedded in rubber. When the core-sheath fiber is combined with rubber, resorcin-formalin latex (such as conventionally used for adhesion of tire cords) ( Since it is not necessary to perform a dip treatment for attaching an adhesive composition such as an RFL) -based adhesive, the bonding process can be simplified. In addition, when adhering organic fibers and rubber using an adhesive composition in reinforcing applications such as tires, in general, the organic fibers are covered with a fiber coating rubber (Skim Rubber) in order to ensure adhesion. However, the core-sheath fiber according to the present invention can obtain a strong adhesive force directly by tread rubber and heat fusion without using a fiber coating rubber.

Further, according to the study of the present inventor, when the core-sheath fiber according to the present invention is vulcanized, the cut end surface of the core part exposed before vulcanization is covered with the resin of the sheath part at the cut end part. Thus, it has been found that a strong fusion between the resin of the sheath and the rubber can be obtained also in this portion. This is thought to be due to the low melting point resin material forming the sheath flowing by heating during vulcanization and entering the gap between the cut end face of the core made of the high melting point resin and the rubber, Thereby, durability against strain after vulcanization can be further improved.
It should be noted that the coating of the cord end during vulcanization is that the core portion that does not melt during vulcanization heat-shrinks the cord in the length direction of the cord, but the sheath portion melts and fluidizes without contracting. 16A to 16D, the resin of the sheath portion is coated on the cord end in the order shown in FIG. First, the core-sheath fibers before vulcanization are aligned in parallel and covered with rubber to produce a sheet-like rubber-fiber composite strip, and then an arbitrary angle at which a reinforcing material is to be disposed as a tire reinforcing layer. Cut the core-sheath cord with. The lengths of the core portion 221 and the sheath portion 222 of the core-sheath cord 200 are cord end surfaces cut at the same position (FIG. 16A). Next, when the green tire is molded and vulcanized at 140 ° C. to 190 ° C., the cord resin of the sheath portion 221 and the core portion 222 does not melt the core resin (A) having a higher melting point. 221 contracts by heat in the direction of the cord length (FIG. 16B), but the lower melting point resin material (B) of the sheath part 222 melts and becomes liquid, and the resin of the sheath part 222 is formed in the void portion formed by shrinking the core. Flows (FIG. 16C), and the resin material (B) of the sheath portion 222 that can be welded to the adherend rubber during vulcanization covers the end surface of the core portion 221 (FIG. 16D). As shown in the fluorescence micrograph of FIG. 17, the end surface of the core is obtained by forming a rubber-fiber composite of core-sheath fibers in a state in which the sheath portion 222 covers the heat-shrinkable portion of the core portion 221 in the cord direction.

  In the core-sheath type composite fiber according to the present invention, the melting point of the high melting point resin (A) forming the core is 150 ° C. or higher, preferably 160 ° C. or higher. When the melting point of the high-melting point resin (A) is less than 150 ° C., when the rubber article is vulcanized, the core of the composite fiber is melted and thinned, or the orientation of the fiber resin molecules is reduced. It will not have sufficient reinforcing performance. In the core-sheath type composite fiber according to the present invention, the olefin polymer (D) forming the sheath part preferably has a melting point of 80 ° C. or higher, more preferably 120 ° C. or higher, and further preferably. Is in the range of 135 ° C. or higher. If the melting point of the olefin polymer (D) is less than 80 ° C., the rubber will not adhere to the surface of the resin material (B) sufficiently at the initial stage of vulcanization. May not be able to obtain a good adhesion. Further, if the melting point of the olefin polymer (D) is 120 ° C. or higher, 130 ° C. as a vulcanization treatment temperature that may be industrially used in a rubber composition containing sulfur and a vulcanization accelerator. In the above, it is preferable because the rubber and the low melting point resin material are thermally fused and at the same time, the vulcanization crosslinking reaction of the rubber composition can be performed. In addition, when the vulcanization temperature is set to 170 ° C. or more in order to shorten the vulcanization time industrially, when the melting point of the olefin polymer (D) is less than 80 ° C., the viscosity of the molten resin is lowered. Too much heat fluidity during vulcanization, and a portion where the sheath thickness is reduced due to the pressure during vulcanization occurs, and strain stress such as adhesion test concentrates on the portion where the sheath resin is thin. Since it may become easy to cause destruction, the melting point of the olefin polymer (D) is more preferably 120 ° C. or higher. On the other hand, if the upper limit of the melting point of the olefin polymer (D) is less than 150 ° C., the vulcanization temperature is 175 ° C. or higher, and the heat flowability of the resin material causes the initial vulcanization with the rubber composition. Compatibility may be obtained. Further, it is preferable that the melting point of the olefin polymer (D) is 145 ° C. or lower because the compatibility of the resin at the initial stage of vulcanization can be obtained at a general vulcanization temperature.

  The rubber reinforcing composite fiber used in the present invention is a resin material (B) containing an olefin polymer (D) having a low melting point in the sheath, and can be directly adhered to the rubber by thermal fusion, The core portion is a composite fiber (C) having a core-sheath structure, which is a high melting point resin (A) having a melting point of 150 ° C. or higher. For example, when the monofilament cord has a single composition, the effects of the present invention cannot be obtained. In a conventional monofilament cord made of a polyolefin resin having a single composition, in the case of a low melting point, even if it can be spread by being melted by heat fusion with the rubber of the rubber article, it can be adhered to the rubber to be adhered. If the molecular chain of the fiber resin that has become a molten melt and is oriented in the cord direction becomes non-oriented, the tensile rigidity as a cord material that reinforces rubber cannot be maintained. On the other hand, in the case of a high melting point where the resin does not become a melt even under heating, the weldability with the rubber becomes low. For this reason, in the monofilament cord of a single composition that is not a composite fiber having the core-sheath structure of the present invention, it is difficult to achieve both contradictory functions of maintaining tensile rigidity and weldability to rubber.

  In the composite fiber (C) according to the present invention, the high melting point resin (A) having a melting point of 150 ° C. or higher that forms the core is not particularly limited as long as it is a known resin that can be formed into a filament by melt spinning. Preferably, a polymer selected from polyolefin resins (P) having a melting point of 150 ° C. or higher, polyester resins (Q), and polyamide resins (R) may be included. Specifically, for example, polyester resin (Q) such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), nylon 6, nylon 66, polyamide resin (R) such as nylon 12, and the like, and polyester resins and polyolefin resins are preferable. Among polyester resins, polytrimethylene terephthalate (PTT) resins are particularly preferred.

  The polytrimethylene terephthalate resin forming the core of the present invention may be a polytrimethylene terephthalate homopolymer, copolymer, or a mixture with other miscible resins. Examples of the copolymerizable monomer of polytrimethylene terephthalate copolymer include acid components such as isophthalic acid, succinic acid and adipic acid, glycol components such as 1,4 butanediol and 1,6 hexanediol, and polytetraethylene. Examples include methylene glycol and polyoxymethylene glycol. The content of these monomers capable of copolymerization is not particularly limited, but is preferably 10% by mass or less because the bending rigidity of the copolymer is lowered. Examples of the polyester resin that can be mixed with the polytrimethylene terephthalate polymer include polyethylene terephthalate, polybutylene terephthalate, and the like, and may be mixed at 50% by mass or less.

  The intrinsic viscosity [η] of the polytrimethylene terephthalate is preferably 0.3 to 1.2, more preferably 0.6 to 1.1. When the intrinsic viscosity is less than 0.3, the strength and elongation of the fiber is low, and when it exceeds 1.2, the productivity becomes difficult due to yarn breakage caused by spinning. The intrinsic viscosity [η] can be measured with an Ostwald viscometer using an o-chlorophenol solution at 35 ° C. Moreover, it is preferable that the melting peak temperature calculated | required from DSC measured according to JIS-K-7121 of polytrimethylene terephthalate is 180 degreeC-240 degreeC. More preferably, it is 200 degreeC-235 degreeC. When the melting peak temperature is in the range of 180 to 240 ° C., the weather resistance is high, and the flexural modulus of the resulting composite fiber can be increased.

  In addition, as an additive of the mixture composed of the polyester resin, for example, a plasticizer, a softening agent, an antistatic agent, an extender, a matting agent, a heat stabilizer, a light stabilizer, a flame retardant, an antibacterial agent, a lubricant, Antioxidants, ultraviolet absorbers, crystal nucleating agents and the like can be added as long as the effects of the present invention are not impaired.

  Further, in order to improve the compatibility at the interface between the core and the sheath, the degree of neutralization with a metal salt of an olefin copolymer containing an unsaturated carboxylic acid or an anhydride monomer described later is 20 % Or more ionomer can be mixed in the range of 1 to 20 parts by mass.

  The polyolefin resin (P) having a melting point of 150 ° C. or higher that forms the core is preferably a high melting point polyolefin resin, particularly preferably a polypropylene resin, and more preferably a crystalline homopolypropylene polymer. Yes, and more preferred is isotactic polypropylene.

In the core-sheath type composite fiber used in the present invention, the core part is composed of a high melting point resin having a melting point of 150 ° C. or higher, and the core part does not melt even in the rubber vulcanization process. The present inventors conducted vulcanization for 15 minutes at 195 ° C., which is higher than normal industrial vulcanization conditions, and observed the cross section of the cord embedded in the rubber after vulcanization. The melting point olefin-based polymer melted and deformed the circular cross-section, but the high-melting point resin in the core maintained the cross-sectional shape of the circular core after the core-sheath composite spinning and became a completely melted melt. In addition, the fiber breaking strength also maintained a strength of 150 N / mm ² or more.

  Thus, if the melting point of the resin at the core of the cord is 150 ° C. or higher, the present inventors melt and cut the core-sheath fiber even when subjected to heat treatment at 195 ° C. during the vulcanization of the rubber article. It was found that the desired effect of the present invention can be obtained. The reason why the material has such heat resistance as to maintain the material strength even at a processing temperature higher than the melting point inherent to the resin is that when the cord is vulcanized at a constant length by being embedded in rubber, a resin such as JIS-K7121 Unlike the method of measuring the melting point without constraining the shape, it is considered that the melting point is higher than the melting point inherent to the resin because it is a constant length constraint that does not shrink the fiber. Under such “constant length restraint” measurement conditions in which the fibers do not shrink, it is known that a high melting point may occur as a thermal phenomenon under the circumstances specific to fiber materials (2nd edition Fiber Handbook) (Published on March 25, 1994, edited by: Textile Society of Japan, published by Maruzen Co., Ltd., page 207, line 13). Regarding this phenomenon, the melting point of the substance is expressed by the equation Tm = ΔHm / ΔSm. In this equation, the crystallinity and the equilibrium melting enthalpy ΔHm do not change if the same fiber resin is used. However, if tension is applied in the cord direction and the length is constant (or stretched) and thermal contraction of the cord during melting is prohibited, molecular chains oriented in the cord direction are difficult to relax due to melting, so the enthalpy of fusion ΔSm It has been considered that the melting point rises as a result of the decrease in. However, with a resin material such as the present invention, it is a cord material that is supposed to be melted at a temperature higher than the resin melting point according to the JIS method, and is examined at a temperature corresponding to the rubber vulcanization process, and by heat fusion with rubber. The knowledge of studying and implementing resin materials suitable for reinforcement for rubber articles that simultaneously adhere directly and at the same time achieve the rigidity of the core resin even under heating in the vulcanization process has been known until the inventors' investigation. There wasn't.

  As a preferred example of the present invention, when a polypropylene resin or a PPT resin is used as a resin having a melting point of 150 ° C. or more constituting the core portion, a known 66 nylon or polyethylene terephthalate conventionally used for tire cords. Although the modulus is lower than that of highly elastic cords such as aramid, it can be adjusted according to the manufacturing conditions such as cord material or draw ratio during spinning so that the elastic modulus is intermediate between these conventional cords and rubber. A feature is that the cord can be disposed at a position in the tire that could not be achieved.

  For example, in the manufacture of rubber articles such as tires, a rubber balloon-like compression device called a bladder is assembled by assembling members made of rubber or a coated cord material and putting the original shape before vulcanization such as raw tires into a mold. Then, there is a vulcanization process in which it is pressed from the inside toward the mold with high-temperature, high-pressure steam. At this time, if the modulus of the cord is too high, the cord material together with the rubber material changes from being placed in the original shape before being vulcanized, such as a raw tire, to the mold with high-temperature, high-pressure steam. In some cases, the cord becomes so-called “cutting thread (thread that cuts a lump of clay, etc.)” and the rubber material assembled into the original shape before vulcanization is cut off. . For this reason, it has been difficult to dispose the high modulus cord in the tire unless the manufacturing measures are taken with the conventional manufacturing method. In particular, in the structure where the cord is arranged at an angle close to the tire circumferential direction in the tire side part, the cord under tension moves by cutting the rubber material from the tire radial direction to the bead side by pressing the steam of high temperature and high pressure etc. However, manufacturing problems are likely to occur.

  On the other hand, the cord of the present invention is a material in which the cord material is also easily stretched as compared with the conventional high-elasticity cord. Even in the case of a product structure and arrangement position that could not be achieved, it is possible to manufacture the product with the conventional method. One of the features of the present invention is that the degree of freedom in designing the tire member can be widened.

  Further, as the olefin polymer (D) used for the resin material forming the sheath, the propylene-α olefin copolymer (H), the propylene-nonconjugated diene copolymer (I), the unsaturated carboxylic acid or What is necessary is just to consist of olefins, such as an ionomer (J) and an olefin homopolymer (K) whose neutralization degree by the metal salt of the olefin copolymer containing the anhydride monomer is 20% or more.

In the propylene-α-olefin random copolymer (H) according to the present invention, a known α-olefin monomer can be used as a comonomer copolymerized with propylene. Moreover, the monomer used as a comonomer is not restricted to 1 type, The multi-component copolymer using two or more types of monomers like a terpolymer is also contained as a preferable thing. Moreover, if it is a range with which the effect made into the objective of this invention is acquired, the monomer which can be copolymerized with another polypropylene can be included, for example in the range of 5 mol% or less.
Preferred examples of these propylene-α-olefin random copolymers (H) include propylene-ethylene random copolymers, propylene-ethylene-butene random copolymers, and butene-propylene random copolymers. -Ethylene random copolymers are most preferred.

  α-olefins having 2 or 4 to 20 carbon atoms, specifically, ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1 , 4-methyl-hexene-1,4,4-dimethylpentene-1 linear or branched α-olefin, cyclopentene, cyclohexene, cycloheptene, and other cyclic olefins. These α-olefins may be used alone or in combination of two or more. Among these, ethylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene are preferable, and ethylene and 1-butene are particularly preferable.

  The propylene content in the propylene-α-olefin random copolymer is preferably 20 to 99.7 mol%, more preferably 75 to 99.5 mol%, and still more preferably 95 to 99.3 mol%. is there. If the propylene content is less than 20 mol%, the impact strength may be insufficient due to the formation of a polyethylene crystal component. In general, a propylene content of 75 mol% or more is preferable because spinnability is improved. Further, when the propylene content is 99.7 mol% or less, the randomness of the molecular chain increases due to addition polymerization of other monomers such as ethylene copolymerized with polypropylene, and the cord becomes easy to be thermally fused. Furthermore, the ethylene content is preferably 0.3 mol% to 80 mol%. When the ethylene content exceeds 80 mol%, the fusion resistance between the sheath portion and the adherend rubber is not preferable because the resistance to fracture of the sheath portion is not sufficient, and cracks are easily generated in the sheath portion, which makes it easy to break. . Further, when the ethylene content is 5% or less, the fusion property when the sheath resins come into contact with each other during spinning becomes small, and the spinnability becomes preferable. Furthermore, when the ethylene content is less than 0.3 mol%, the polymer consisting of polypropylene has less disorder of molecular chain orientation due to addition polymerization of the ethylene monomer, and as a result, the crystallinity becomes high. The heat-fusibility of the resin in the sheath portion is reduced.

  As for the propylene-α-olefin copolymer (H), a random copolymer in which the block amount in the NMR measurement of the repeating unit of the same vinyl compound portion is 20% or less of the wholly aromatic vinyl compound portion is preferable. The reason why the random copolymer is preferable is that when the propylene-α-olefin copolymer (H) has low crystallinity and is not oriented, the adherent rubber component having low orientation and the melting due to the compatibility of the molecular chains during heating This is because it is easy to obtain wearability.

  The propylene-nonconjugated diene copolymer (I) according to the present invention can be obtained by polymerizing propylene and a known nonconjugated diene. The monomers used as these comonomers are not limited to one type, and multi-component copolymers using two or more types of monomers such as terpolymers are also included as preferable ones. In addition, within the range in which the intended effect of the present invention can be obtained, other monomers that can be copolymerized with polypropylene can be included in a range of, for example, 5 mol% or less, and the polymer containing these monomers is included. Is a propylene-nonconjugated diene copolymer (I). Preferable examples include 1-butene-propylene copolymer.

  Non-conjugated diene monomers include 5-ethylidene-2-norbornene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, 5-vinyl-2-norbornene, 4,8-dimethyl-1,4,8- Examples include decatriene and 4-ethylidene-8-methyl-1,7-nonadiene. In particular, when a non-conjugated diene is introduced into ethylene and propylene as a third component, if an ethylene-propylene-diene copolymer (EPDM) component is included, it is due to sulfur as well as adhesion at the interface with the rubber to be adhered. Since the component which has co-vulcanizability is contained, it is preferable. For example, as the propylene-nonconjugated diene copolymer (I), an ethylene-propylene-diene copolymer containing 5-ethylidene-2-norbornene as a diene component can be suitably used.

  Moreover, as a propylene content in the said propylene-nonconjugated diene copolymer (I), Preferably it is 20-99.7 mol%, More preferably, it is 30-75 mol%, More preferably, it is 40-60 mol%. When the propylene content is less than 20 mol%, a blocking phenomenon in which the sheath resins of the cords stick to each other after spinning tends to occur. On the other hand, if it is 30 mol% or less, the surface of the sheath resin is likely to be disturbed due to surface friction during spinning. On the other hand, if the propylene content is 99.7 mol% or more, the amount of other monomers copolymerized with polypropylene decreases, the randomness of the molecular chain decreases, and the crystallinity of polypropylene increases. Is a low code. Further, when the content of the non-conjugated diene monomer exceeds 80 mol%, in the fusion between the sheath portion and the adherend rubber, the fracture resistance of the sheath portion becomes insufficient, and cracks occur in the sheath portion. It is not preferable because it easily occurs and breaks. Furthermore, when the ethylene content is less than 0.3 mol%, compatibility with the adherend rubber and improvement in adhesion due to co-vulcanization are reduced.

As the ionomer (J) having a neutralization degree of 20% or more with a metal salt of an olefin copolymer containing an unsaturated carboxylic acid or anhydride monomer according to the present invention, an ethylene-ethylenically unsaturated carboxylic acid is used. An ionomer obtained by neutralizing a part or all of the carboxyl groups with a metal, such as an acid copolymer or a modified product of an unsaturated carboxylic acid of polyolefin, can be used. Examples of the metal species constituting the ionomer include monovalent metals such as lithium, sodium, and potassium, and polyvalent metals such as magnesium, calcium, zinc, copper, cobalt, manganese, lead, and iron. One or more of these metal species can be used. Of these, sodium, magnesium, calcium, or zinc is preferable. Particularly preferred is sodium or zinc.
In the study by the present inventors, in the use of the resin material (B) of the sheath portion, an ionomer obtained by neutralizing 20% or more of an ethylene-ethylenically unsaturated carboxylic acid copolymer with a metal salt is preferable. The reason for this is that when the sheath resin material becomes proton H ⁺ donating acidic atmosphere due to a functional group such as carboxylic acid, even if sulfur migrates from the coated rubber to the sheath resin material and is activated, the proton H ⁺ This is because, since the polyvulcanized product is reduced, the polyvulcanized product cannot be formed, so that it becomes easy to create an environment in which the adhesiveness with the adherend rubber cannot be strengthened. The neutralization degree between the carboxylic acid and the metal salt is preferably 100% or more. However, since the carboxylic acid is a weak acid, the effect of the present invention can be obtained even when the neutralization degree of the carboxylic acid is 20%. . Moreover, the neutralization degree of preferable carboxylic acid is 20 to 250%, More preferably, it is 70 to 150%.

  For example, as ethylenically unsaturated carboxylic acid monomers, vinyl acetate, vinyl esters such as vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, nbutyl acrylate, isobutyl acrylate, isooctyl acrylate, etc. Methacrylic acid esters such as methacrylic acid esters such as methyl methacrylate and isobutyl methacrylate, and maleic acid esters such as dimethyl maleate and diethyl maleate. Among these, methyl acrylate and methyl methacrylate are preferable. For example, as the ionomer (J), an ionomer of an ethylene / methacrylic acid copolymer can be suitably used.

In addition, the neutralization degree in this invention is defined by a following formula.
Degree of neutralization (%) = 100 × [(number of moles of cation component of resin component × valence of cation component) + (number of moles of metal component of basic inorganic metal compound × valence of metal component)] / [(Mole number of carboxyl group of resin component)
The amount of the cation component and the amount of the anion component can be determined by a method for examining the degree of neutralization of the ionomer such as neutralization titration.

  As the olefin homopolymer (K) according to the present invention, an ethylene homopolymer such as high density polyethylene, low density polyethylene or linear low density polyethylene, isotactic polypropylene, atactic polypropylene, or Examples include propylene homopolymers such as syndiotactic polypropylene, 4-methylpentene-1 homopolymer, 1-butene homopolymer, polybutadiene, polyisoprene, polynorbornene and the like. Although it does not restrict | limit in particular, In this invention, a high density polyethylene, a polybutadiene, etc. are mentioned as a preferable example.

  Examples of the method for producing these olefin copolymer resins include slurry polymerization, gas phase polymerization, or liquid phase bulk polymerization using an olefin polymerization catalyst such as a Ziegler catalyst or a metallocene catalyst. Either polymerization or continuous polymerization can be employed.

  In the present invention, the olefin polymer (D) contained in the resin material (B) of the sheath part is a propylene-α olefin copolymer (H), a propylene-nonconjugated diene copolymer (I), or unsaturated. An ionomer (J) or olefin homopolymer (K) having a degree of neutralization with a metal salt of an olefin copolymer containing a carboxylic acid or its anhydride monomer can be used alone. Two or more kinds can be mixed and used.

  Further, the resin material (B) of the sheath part includes, together with the olefin polymer (D), a styrene elastomer (L) containing a single molecular chain mainly composed of styrene monomers, and vulcanization acceleration. One or more selected from the agent (M), the vulcanization acceleration aid (N), and the filler (O) can be included.

  In this invention, it is preferable that the resin material which comprises a sheath part further contains the styrene-type elastomer (L) containing the single molecular chain formed by arranging the styrene monomer mainly continuously as a compatibilizing agent. By mix | blending a styrene-type elastomer (L), compatibility with a resin material and rubber | gum can be improved and adhesiveness can be improved.

That is, the low melting point resin material is mainly composed of a polyolefin resin such as a homopolymer such as polyethylene or polypropylene, an ethylene-propylene random copolymer, or the like, which becomes a resin composition having a melting point range specified in the present invention. Although it is a composition, it is known that the resin composition which mixed these generally becomes a phase-separated structure. Therefore, by adding the styrene elastomer (L) as a block copolymer composed of soft segments and hard segments, compatibilization of the phase interface can be promoted. The styrenic elastomer (L) has an adhesiveness at the interface between the high melting point resin as the core component and the resin material as the sheath component, and styrene-butadiene rubber (SBR) and butadiene rubber (included in the sheath component and the adherend rubber). It is preferable to have a segment that interacts with a molecular structure such as BR), butyl rubber (IIR), natural rubber (IR) having a polyisoprene structure, etc., because adhesion with the adherend rubber is improved. In particular, when the adherent rubber contains styrene-butadiene rubber (SBR), if the sheath component contains a styrene-based block copolymer containing a styrene component, compatibility with the interface with the adherent rubber in fusion bonding Is preferable, and the adhesive strength is improved.
The block copolymer in the present invention is a polymer composed of two or more types of monomer units, and forms a single molecular chain (block) in which at least one monomer unit is mainly arranged long and continuously. Meaning a copolymer. The styrenic block copolymer means a block copolymer including a block in which styrene monomers are mainly linked and arranged long.

  As the styrene elastomer (L), specifically, a styrene block copolymer can be used, and one containing styrene and a conjugated diolefin compound is preferable. More specifically, as the styrene elastomer (L), a styrene-butadiene polymer, a polystyrene-poly (ethylene / propylene) block copolymer, a styrene-isoprene block polymer, and these styrene and Examples thereof include a polymer obtained by hydrogenating a double bond of a block copolymer with butadiene and hydrogenating it completely or partially. The styrene elastomer may be modified with maleic acid.

  Specific examples of the styrene-butadiene polymer include styrene-butadiene polymer (SBS), styrene-ethylene-butadiene copolymer (SEB), styrene-ethylene-butadiene-styrene copolymer (SEBS), and styrene-butadiene. -Butylene-styrene copolymer (SBBS), partially hydrogenated styrene-isoprene-butadiene-styrene copolymer, or Asahi Kasei Chemicals Co., Ltd. O. E. Examples thereof include a hydrogenated product of a block copolymer having a styrene block at both ends and a block composed of a styrene block and a random copolymer of butadiene in the main chain. Polystyrene-poly (ethylene / propylene) block polymers include polystyrene-poly (ethylene / propylene) block copolymers (SEP), polystyrene-poly (ethylene / propylene) block-polystyrene (SEPS), polystyrene-poly ( Examples include ethylene / butylene) block-polystyrene (SEBS) and polystyrene-poly (ethylene-ethylene / propylene) block-polystyrene (SEEPS). Examples of the styrene-isoprene block polymer include polystyrene-polyisoprene-polystyrene copolymer (SIS) and polystyrene-polyisobutylene-polystyrene block copolymer (SIBS). In the present invention, among these, from the viewpoint of adhesion to rubber and compatibility, styrene-isoprene copolymer, styrene-butadiene polymer, styrene-butadiene-butylene-styrene copolymer, and styrene-ethylene. A butadiene-styrene copolymer can be preferably used. In the case where the rubber to be adhered is a composition comprising a rubber having a low polarity such as BR, SBR, and NR, the styrene block copolymer or its hydrogenated product does not have a functional group having a strong polarity due to modification or the like. However, since compatibility becomes high, it is preferable.

  Modification in the case where a polar group is further introduced into the hydrogenated product of the styrene-butadiene polymer can be performed, for example, by introducing an amino group, a carboxyl group or an acid anhydride group into the hydrogenated product. Although not particularly limited, in the present invention, as the modification for introducing a polar group, 3-lithio-1- [N, N-bis (trimethylsilyl)] aminopropane, 2-lithio-1- [N, N-bis] Modification by introduction of an unsaturated amino group, such as (trimethylsilyl)] aminoethane, 3-lithio-2,2-dimethyl-1- [N, N-bis (trimethylsilyl)] aminopropane, can be mentioned as a preferred example. .

  The content of the styrene-based elastomer (L) is 0.1 to 30 parts by mass, particularly 1 to 30 parts by mass with respect to 100 parts by mass of the total amount of resin components such as olefin polymers contained in the resin material constituting the sheath. The amount can be 15 parts by mass. By making content of a styrene-type elastomer (L) into the said range, the compatibility improvement effect of a resin material and rubber | gum can be acquired favorably. Since these styrene-based elastomers (L) are elastomers, they have no crystal structure and are only non-crystalline parts. Therefore, the styrenic elastomers (L) do not have a melting point at which the crystalline parts are broken by the heating and heating of the polymer to show fluidity. Therefore, the amorphous rubber, which is similarly amorphous, is heated to a temperature higher than the melting point of the polymer so as to give fluidity by breaking the crystal part of the polymer chain like the general melting olefin polymer (D). Even without heating, fluidity can be obtained by heat. Since the styrene-based elastomer (L) according to the present invention is a component that enhances the compatibility of the polymer with the adherend rubber, the olefin-based polymer (D) is flowed by heat by being included in the resin material (B). Then, by increasing the compatibility with the adherend rubber, the weldability between the adherend rubber and the resin material (B) can be further enhanced.

  Moreover, in this invention, the resin material which comprises a sheath part can contain a vulcanization accelerator (M) further. By containing the vulcanization accelerator (M), an interaction at the rubber interface can be obtained due to the effect that the sulfur content in the adherend rubber becomes a transition state between the vulcanization accelerator and the polyvulcanizate, and rubber is obtained. The surface distribution of the sheath resin from inside or the amount of sulfur transferred to the inside of the resin increases. Further, when a conjugated diene capable of sulfur vulcanization is included in the component of the sheath resin, the co-reaction with the adherend rubber is promoted, and the adhesiveness between the resin material and the rubber can be further improved.

  Vulcanization accelerators include basic silica, primary, secondary, and tertiary amines, organic acid salts of these amines or their adducts and salts, aldehyde ammonia accelerators, aldehyde amine accelerators, and the like. As other vulcanization accelerators, the sulfur atom of the vulcanization accelerator opens when it approaches the cyclic sulfur in the system, and becomes a transition state, which is an active vulcanization accelerator. -Sulfenamide accelerators, guanidine accelerators, thiazole accelerators, thiuram accelerators, dithiocarbamic acid accelerators, etc., which can activate sulfur by generating a polyvulcanizate.

  The Lewis basic compound is not particularly limited as long as it is a Lewis base in the definition of Lewis' acid base and can provide an electron pair. These include nitrogen-containing compounds having a lone electron pair on the nitrogen atom, and specifically, basic vulcanization accelerators known in the rubber industry can be used.

Specific examples of the basic compound include aliphatic primary, secondary or tertiary amines having 5 to 20 carbon atoms, such as n-hexylamine, octylamine, coconutamine, laurylamine, 1-aminooctadecane, oleylamine, alkylamines such as tallowamine, dibutylamine, distearylamine, dialkylamines such as di (2-ethylhexyl) amine, tributylamine, trioctylamine, dimethylcoconutamine, dimethyldecylamine, dimethyllauryl Acyclic monoamines and derivatives thereof such as amines, dimethylmyristylamines, dimethylpartimylamines, dimethylstearylamines, dimethylbehenylamines, dilaurylmonomethylamines, and the like, and their salts, esters Acyclic polyamines and derivatives thereof such as range amine, beef tallow propylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, polyethyleneimine and the like, and alicyclic such as cyclohexylamine Examples thereof include polyamines and derivatives thereof and salts thereof, alicyclic polyamines such as hexamethylenetetramine and derivatives thereof, and salts thereof, aniline, alkylaniline, diphenylaniline, 1-naphthylaniline, N-phenyl-1-naphthylamine and the like. Aromatic monoamines and their derivatives and their salts, phenylenediamine, diaminotoluene, N-alkylphenylenediamine, benzidine, guanidines, n-butyl Aldehyde aniline, aromatic polyamine compounds and their derivatives, such as, and the like.
Examples of guanidines include 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, 1-o-tolylbiguanide, dicatechol borate di-o-tolylguanidine salt, 1,3-di- Examples include o-cumenyl guanidine, 1,3-di-o-biphenyl guanidine, 1,3-di-o-cumenyl-2-propionyl guanidine, and the like. Of these, 1,3-diphenylguanidine is preferable because of its high reactivity.

  Examples of the organic acid that forms a salt with the amine include carboxylic acid, carbamic acid, 2-mercaptobenzothiazole, and dithiophosphoric acid. Examples of the substance that forms an adduct with the amine include alcohols and oximes. Specific examples of the organic acid salt or adduct of amine include n-butylamine / acetate, dibutylamine / oleate, hexamethylenediamine / carbamate, dicyclohexylamine salt of 2-mercaptobenzothiazole, and the like.

Also, for example, as a nitrogen-containing heterocyclic compound that becomes basic by having a lone electron pair on the nitrogen atom, monocyclic nitrogen-containing compounds such as pyrazole, imidazole, pyrazoline, imidazoline, pyridine, pyrazine, pyrimidine, triazine, etc. Examples thereof include compounds and derivatives thereof, benzimidazoles, purines, quinolines, peteridines, acridines, quinoxalines, phthalazines, and the like, and their derivatives.
Further, examples of the heterocyclic compound having a heteroatom other than a nitrogen atom include heterocyclic compounds containing nitrogen and other heteroatoms such as oxazoline and thiazoline and derivatives thereof.

  Specific examples of the other vulcanization accelerators include known vulcanization accelerators such as thioureas, thiazoles, sulfenamides, thiurams, dithiocarbamic acids, and xanthogenic acids.

  Examples of thioureas include N, N′-diphenylthiourea, trimethylthiourea, N, N′-diethylthiourea, N, N′-dimethylthiourea, N, N′-dibutylthiourea, ethylenethiourea, N, N′— Diisopropylthiourea, N, N′-dicyclohexylthiourea, 1,3-di (o-tolyl) thiourea, 1,3-di (p-tolyl) thiourea, 1,1-diphenyl-2-thiourea, Examples include 2,5-dithiobiurea, guanylthiourea, 1- (1-naphthyl) -2-thiourea, 1-phenyl-2-thiourea, p-tolylthiourea, o-tolylthiourea and the like. Of these, N, N'-diethylthiourea, trimethylthiourea, N, N'-diphenylthiourea and N, N'-dimethylthiourea are preferred because of their high reactivity.

  Thiazoles include 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, zinc salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (N, N-diethylthiocarbamoyl) Thio) benzothiazole, 2- (4′-morpholinodithio) benzothiazole, 4-methyl-2-mercaptobenzothiazole, di- (4-methyl-2-benzothiazolyl) disulfide, 5-chloro-2-mercaptobenzothiazole, 2-mercaptobenzothiazole sodium, 2-mercapto-6-nitrobenzothiazole, 2-mercapto-naphtho [1,2-d] thiazole, 2-mercapto-5-methoxybenzothiazole, 6-amino-2-mercaptobenzothiazole Etc. It is below. Among these, 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide, zinc salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (4′-morpholinodithio) benzothiazole Is preferable because of its high reactivity. In addition, for example, di-2-benzothiazolyl disulfide and zinc salt of 2-mercaptobenzothiazole have high solubility even when added to a relatively non-polar polymer, and therefore, spinnability due to deterioration of surface properties due to precipitation or the like. This is a particularly preferable example because it is difficult for the lowering of the film to occur.

  Examples of the sulfenamides include N-cyclohexyl-2-benzothiazolylsulfenamide, N, N-dicyclohexyl-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N-methyl-2-benzothiazolylsulfenamide, N-ethyl-2-benzothiazolylsulfenamide, N-propyl-2-benzothiazolylsulfenamide Phenamide, N-butyl-2-benzothiazolylsulfenamide, N-pentyl-2-benzothiazolylsulfenamide, N-hexyl-2-benzothiazolylsulfenamide, N-pentyl-2-benzothia Zolylsulfenamide, N-octyl-2-benzothiazolylsulfur Enamide, N-2-ethylhexyl-2-benzothiazolylsulfenamide, N-decyl-2-benzothiazolylsulfenamide, N-dodecyl-2-benzothiazolylsulfenamide, N-stearyl-2-benzo Thiazolylsulfenamide, N, N-dimethyl-2-benzothiazolylsulfenamide, N, N-diethyl-2-benzothiazolylsulfenamide, N, N-dipropyl-2-benzothiazolylsulfenamide N, N-dibutyl-2-benzothiazolylsulfenamide, N, N-dipentyl-2-benzothiazolylsulfenamide, N, N-dihexyl-2-benzothiazolylsulfenamide, N, N- Dipentyl-2-benzothiazolylsulfenamide, N, N-dioctyl-2-benzothia Rylsulfenamide, N, N-di-2-ethylhexylbenzothiazolylsulfenamide, N-decyl-2-benzothiazolylsulfenamide, N, N-didodecyl-2-benzothiazolylsulfenamide, N , N-distearyl-2-benzothiazolylsulfenamide and the like. Among these, N-cyclohexyl-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide, and N-oxydiethylene-2-benzothiazolesulfenamide are highly reactive. Therefore, it is preferable. In addition, for example, N-cyclohexyl-2-benzothiazolylsulfenamide and N-oxydiethylene-2-benzothiazolylsulfenamide have high solubility even when added to a relatively nonpolar polymer, and therefore, precipitation, etc. This is a particularly preferred example because it is difficult for a decrease in spinnability and the like due to deterioration of the surface properties due to.

  Thiurams include tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrapropylthiuram disulfide, tetraisopropylthiuram disulfide, tetrabutylthiuram disulfide, tetrapentylthiuram disulfide, tetrahexylthiuram disulfide, tetraheptylthiuram disulfide, tetraoctylthiuram disulfide, tetra Nonyl thiuram disulfide, tetradecyl thiuram disulfide, tetradodecyl thiuram disulfide, tetrastearyl thiuram disulfide, tetrabenzyl thiuram disulfide, tetrakis (2-ethylhexyl) thiuram disulfide, tetramethyl thiuram monosulfide, tetraethyl thiuram monosulfide, tetrapropyl thiura Monosulfide, tetraisopropylthiuram monosulfide, tetrabutylthiuram monosulfide, tetrapentylthiuram monosulfide, tetrahexylthiuram monosulfide, tetraheptylthiuram monosulfide, tetraoctylthiuram monosulfide, tetranonylthiuram monosulfide, tetradecylthiuram monosulfide Tetradodecyl thiuram monosulfide, tetrastearyl thiuram monosulfide, tetrabenzyl thiuram monosulfide, dipentamethylene thiuram tetrasulfide and the like. Of these, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, and tetrakis (2-ethylhexyl) thiuram disulfide are preferred because of their high reactivity. In addition, when the alkyl group contained in the accelerator compound is large, in the case of a relatively non-polar polymer, the solubility tends to increase, and it is difficult to cause a decrease in spinnability due to deterioration of surface properties due to precipitation or the like. Tetrabutyl thiuram disulfide or tetrakis (2-ethylhexyl) thiuram disulfide are particularly preferred examples.

Dithiocarbamates include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dipropyldithiocarbamate, zinc diisopropyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dipentyldithiocarbamate, zinc dihexyldithiocarbamate, zinc diheptyldithiocarbamate, and dioctyldithiocarbamate. Zinc acid, zinc di (2-ethylhexyl) dithiocarbamate, zinc didecyldithiocarbamate, zinc diddecyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, zinc dibenzyldithiocarbamate, Copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dipropyldithiocarbamate, Copper isopropyldithiocarbamate, copper dibutyldithiocarbamate, copper dipentyldithiocarbamate, copper dihexyldithiocarbamate, copper diheptyldithiocarbamate, copper dioctyldithiocarbamate, copper di (2-ethylhexyl) dithiocarbamate, copper didecyldithiocarbamate, didodecyldithiocarbamate Acid copper, copper N-pentamethylenedithiocarbamate, copper dibenzyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dipropyldithiocarbamate, sodium diisopropyldithiocarbamate, sodium dibutyldithiocarbamate, sodium dipentyldithiocarbamate, dihexyldithiocarbamine Acid sodium, diheptyldithio Sodium carbamate, sodium dioctyl dithiocarbamate, sodium di (2-ethylhexyl) dithiocarbamate, sodium didecyldithiocarbamate, sodium didodecyldithiocarbamate, sodium N-pentamethylenedithiocarbamate, sodium dibenzyldithiocarbamate, second dimethyldithiocarbamate Iron, ferric diethyldithiocarbamate, ferric dipropyldithiocarbamate, ferric diisopropyldithiocarbamate, ferric dibutyldithiocarbamate, ferric dipentyldithiocarbamate, ferric dihexyldithiocarbamate, diheptyldithiocarbamate Diiron, ferric dioctyldithiocarbamate, ferric di (2-ethylhexyl) dithiocarbamate, didecyldi Examples thereof include ferric thiocarbamate, ferric didodecyldithiocarbamate, ferric N-pentamethylenedithiocarbamate, ferric dibenzyldithiocarbamate and the like.
Of these, zinc N-ethyl-N-phenyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, and zinc dibutyldithiocarbamate are desirable because of their high reactivity. In addition, when the alkyl group contained in the accelerator compound is large, in the case of a relatively non-polar polymer, the solubility tends to increase, and it is difficult to cause a decrease in spinnability due to deterioration of surface properties due to precipitation or the like. In particular, zinc dibutyldithiocarbamate is a particularly preferable example.

  Xanthates include zinc methylxanthate, zinc ethylxanthate, zinc propylxanthate, zinc isopropylxanthate, zinc butylxanthate, zinc pentylxanthate, zinc hexylxanthate, zinc heptylxanthate, zinc octylxanthate , Zinc 2-ethylhexylxanthate, zinc decylxanthate, zinc dodecylxanthate, potassium methylxanthate, potassium ethylxanthate, potassium propylxanthate, potassium isopropylxanthate, potassium butylxanthate, potassium pentylxanthate, hexylxanthogen Potassium acetate, potassium heptylxanthate, potassium octylxanthate, 2-ethyl Potassium xylxanthate, potassium decylxanthate, potassium dodecylxanthate, sodium methylxanthate, sodium ethylxanthate, sodium propylxanthate, sodium isopropylxanthate, sodium butylxanthate, sodium pentylxanthate, sodium hexylxanthate, Examples include sodium heptyl xanthate, sodium octyl xanthate, sodium 2-ethylhexyl xanthate, sodium decyl xanthate, sodium dodecyl xanthate, and the like. Of these, zinc isopropylxanthate is preferable because of its high reactivity.

  The vulcanization accelerator (M) may be premixed in an inorganic filler, oil, polymer or the like and used for blending in the sheath resin of the core-sheath fiber for rubber reinforcement. These vulcanization accelerators and retarders may be used alone or in combination of two or more.

  Content of a vulcanization accelerator (M) is 0.05-20 mass parts with respect to 100 mass parts of resin components, such as an olefin polymer contained in the resin material which comprises a sheath part, Especially, it is 0. .2 to 5 parts by mass. By making content of a vulcanization accelerator into the said range, the adhesive improvement effect of a resin material and rubber | gum can be acquired favorably.

  In addition to the components described above, a thermoplastic rubber (TPV) cross-linked to a polypropylene-based copolymer may be used for the resin material constituting the sheath for the purpose of increasing the adhesion at the interface with the adherend rubber composition. ), Or “other thermoplastic elastomer (TPZ)” in the classification of thermoplastic elastomers described in JIS K6418. They can finely disperse partially or highly crosslinked rubber in the continuous phase of the matrix of the thermoplastic resin composition of the resin material. Examples of the crosslinked thermoplastic rubber include acrylonitrile-butadiene rubber, natural rubber, epoxidized natural rubber, butyl rubber, and ethylene / propylene / diene rubber. Other thermoplastic elastomers (TPZ) include syndiotactic-1,2-polybutadiene resin or trans-polyisoprene resin.

  In order to add other properties such as oxidation resistance to the high melting point resin and the olefin polymer, the normal resin is used within a range that does not significantly impair the effects of the present invention and workability during spinning. Additives added to can also be blended. As this additional component, conventionally known nucleating agents, antioxidants, neutralizing agents, light stabilizers, process oils, ultraviolet absorbers, lubricants, antistatic agents, fillers used as compounding agents for polyolefin resins, etc. Various additives such as (O), metal deactivators, peroxides, antibacterial / antifungal agents, fluorescent whitening agents, and vulcanization accelerators (N) used as compounding agents for rubber compositions, etc. Additives other than can be used.

Vulcanization accelerating aids (N) include monovalent metals such as lithium, sodium and potassium, formates such as polyvalent metals such as magnesium, calcium, zinc, copper, cobalt, manganese, lead and iron, acetates, Examples thereof include basic inorganic metal compounds such as nitrates, carbonates, hydrogen carbonates, oxides, hydroxides, and alkoxides.
Specifically, metal hydroxides such as magnesium hydroxide, calcium hydroxide, sodium hydroxide, lithium hydroxide, potassium hydroxide, copper hydroxide; magnesium oxide, calcium oxide, zinc oxide (zinc white), copper oxide Metal carbonates such as magnesium carbonate, calcium carbonate, sodium carbonate, lithium carbonate, and potassium carbonate.
Among these, as the alkali metal salt, a metal oxide or a hydroxide is preferable, and magnesium hydroxide and zinc oxide are particularly preferable.

Fillers (O) include alumina, silica-alumina, magnesium chloride, calcium carbonate, talc, montmorillonite, zakonite, beidellite, nontronite, saponite, hectorite, stevensite, bentonite, teniolite and other smectites, vermiculite, Examples thereof include inorganic particulate carriers such as carbon black and mica group, and porous organic carriers such as polypropylene, polyethylene, polystyrene, styrenedivinylbenzene copolymer, and acrylic acid copolymer. These fillers are blended as fillers to reinforce the sheath part when the sheath part is not sufficiently resistant to fracture in the adhesion between the sheath part and the adherend rubber, and cracks occur in the sheath part. can do.
Examples of the carbon black include furnace black such as SAF carbon black, SAF-HS carbon black, ISAF carbon black, ISAF-HS carbon black, and ISAF-LS carbon black.

  As nucleating agents, sorbitol compounds such as sodium 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphate, talc, 1,3,2,4-di (p-methylbenzylidene) sorbitol And hydroxy-di (aluminum t-butylbenzoate).

  Examples of the antioxidant include tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate and 1,1,3-tris (2-methyl-4) as phenolic antioxidants. -Hydroxy-5-t-butylphenyl) butane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythritol-tetrakis {3- (3,5-di-t- Butyl-4-hydroxyphenyl) propionate}, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2 -{3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxas B [5,5] undecane, etc. 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethyl-pen Jill) isocyanuric acid.

  Phosphorus antioxidants include tris (mixed, mono and dinonylphenyl phosphite), tris (2,4-di-t-butylphenyl) phosphite, 4,4′-butylidenebis (3-methyl-6). -T-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5-t-butylphenyl) butane, bis (2,4-di -T-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-t-butyl- 5-methylphenyl) -4,4′-biphenylenediphosphonite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phos Or the like can be mentioned Aito. Examples of the sulfur-based antioxidant include di-stearyl-thio-di-propionate, di-myristyl-thio-di-propionate, pentaerythritol-tetrakis- (3-lauryl-thio-propionate), and the like.

  Examples of the neutralizing agent include calcium stearate, zinc stearate, hydrotalcite and the like.

  Examples of hindered amine stabilizers include polycondensates of dimethyl oxalate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, tetrakis (1,2,2, 6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, N, N-bis (3 -Aminopropyl) ethylenediamine-2,4-bis {N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino} -6-chloro-1,3,5-triazine condensation Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2 , 4- Yl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {2,2,6,6-tetramethyl-4-piperidyl} imino], poly [(6-morpholino-s -Triazine-2,4-diyl) [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] And so on.

  Examples of the lubricant include higher fatty acid amides such as oleic acid amide, stearic acid amide, behenic acid amide, and ethylene bis stearoid, silicone oil, and higher fatty acid esters.

  Examples of the antistatic agent include higher fatty acid glycerin ester, alkyl diethanolamine, alkyl diethanolamide, alkyl diethanolamide fatty acid monoester and the like.

  Examples of the ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2 And ultraviolet absorbers such as' -hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole.

  Examples of the process oil include paraffinic process oil, naphthenic process oil, aroma based process oil, rosin based process oil, and natural vegetable process oil. Preferable examples include naphthenic process oil or a mixture of naphthenic process oil and straight asphalt.

  Examples of the light stabilizer include n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4 ′. -Hydroxybenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl-2- (4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl) ethanol succinate Condensate, poly {[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetra Methyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]}, N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- And the like 1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate.

  In particular, from the viewpoint of the combination of the core part and the sheath part, as the same olefin resin, it is possible to use a high melting point polyolefin resin for the core part and a low melting point polyolefin resin for the sheath part. This is preferable because the compatibility of the parts is good. Unlike the case where different types of resins are used for the core and the sheath by using an olefin resin for both the core and the sheath, the bonding force at the core-sheath polymer interface is high, and the core / sheath. Since it has sufficient peeling resistance against interfacial peeling between the parts, the characteristics as a composite fiber can be sufficiently exhibited over a long period of time. Specifically, a crystalline propylene homopolymer having a melting point of 150 ° C. or higher is used as the high melting point polyolefin-based resin in the core, and an ethylene-propylene copolymer or ethylene-propylene is used as the low melting point polyolefin resin in the sheath. It is preferable to use a polypropylene-based copolymer resin obtained by copolymerizing polypropylene with a component capable of copolymerizing with polypropylene, such as a butene-propylene terpolymer, in particular, an ethylene-propylene random copolymer. It is particularly preferable that the high melting point polyolefin-based resin in the core is isotactic polypropylene because of good fiber forming properties during spinning.

  In this case, the melt flow index (melt flow rate, MFR) (MFR1) of the high melting point polyolefin resin and the melt flow index (MFR2) of the low melting point polyolefin resin are particularly limited as long as they can be spun. Although it is not, 0.3-100 g / 10min is preferable. The same applies to the melt flow index of the high melting point resin used for the core other than the high melting point polyolefin resin.

  In particular, the melt flow index (MFR1) of the high melting point resin including the high melting point polyolefin resin is preferably 0.3 to 18 g / 10 min, particularly preferably 0.5 to 15 g / 10 min, more preferably 1 to 10 g / 10 min. You can choose from those in the range. When the MFR of the high-melting point resin is within the above range, the spinning take-out property and stretchability are improved, and the melt of the high-melting point resin in the core part is heated under the vulcanization process for producing the rubber article. This is because the form of the cord can be maintained without flowing.

  Further, the melt flow index (MFR2) of the low melting point polyolefin-based resin is preferably 5 g / 10 min or more, particularly preferably 5 to 70 g / 10 min, and further preferably 10 to 30 g / 10 min. In order to improve the heat fusion property of the low melting point polyolefin resin in the sheath, a resin having a large MFR is preferable because the resin easily flows and fills in the gap with the rubber to be deposited. On the other hand, if the MFR is too large, if there are other reinforcing members, such as ply cords or bead cores, in the vicinity where the composite fiber is disposed, if there is an unintended gap in the rubber covering the composite fiber, Since the melt of the low melting point polyolefin-based resin may wet and spread on the surface of the fiber material of the cord, it is particularly preferably 70 g / 10 min or less. More preferably, it is 30 g / 10 min or less. In this case, when the composite fibers are in contact with each other, the melt of the low melting point polyolefin melts and spreads between the fibers so as to become a lump-like fiber bonded body. This is preferable because the occurrence of this phenomenon is reduced. Further, if it is 20 g / 10 min or less, since the fracture resistance of the resin in the sheath portion is increased when the rubber to be fused is peeled off, it is more preferable that the rubber adheres firmly to the rubber.

  The MFR value (g / 10 min) is the same as JIS-K-7210. The melt flow rate of the polypropylene resin material is 230 ° C. and the load of 21.18 N (2160 g) under the load of the polyethylene resin material. The rate is the melt flow rate measured at a temperature of 190 ° C. and a load of 21.18 N (2160 g), respectively.

  As a ratio of the core part and the sheath part in the composite fiber in the present invention, the ratio of the core part in the composite fiber is preferably 10 to 95% by mass, and more preferably 30 to 80% by mass. When the ratio of the core portion is too small, the strength of the composite fiber is lowered, and there is a possibility that sufficient reinforcing performance cannot be obtained. In particular, the core portion ratio of 50% by mass or more is preferable because the reinforcing performance can be enhanced. On the other hand, if the ratio of the core part is too large, the ratio of the sheath part is too small, and the core part is likely to be exposed in the composite fiber, and there is a possibility that sufficient adhesion with the rubber cannot be obtained.

In the present invention, the form of the composite fiber (C) when applied to the auxiliary reinforcing layer is not particularly limited, but is preferably a monofilament or a cord formed by bundling up to 10 monofilaments, more preferably It is a monofilament cord. The reason for this is that the fiber aggregate of the composite fiber (C) in the present invention is in the form of a cord, a twisted cord, a nonwoven fabric, or a woven fiber in which 10 or more monofilaments are bundled. Since the low melting point resin material (B) constituting the sheath melts when vulcanized, the filaments are welded together and the melt penetrates each other, so that a lump of foreign matter is removed in the rubber article. This is because it may be formed. If such foreign matter is generated, cracks may develop from the bulky foreign matter in the rubber article due to rolling distortion during use of the tire, and separation may occur. For this reason, when the composite fiber (C) becomes a fiber assembly in a rubber article, the more the number of filaments bundled, the more difficult the rubber penetrates between the cords, and it becomes easier to form a lump of foreign matter. The number of filaments to be bundled is preferably 10 or less.
In particular, as the auxiliary reinforcing layer, the composite fiber (C) is preferably a monofilament cord. The reason for this is that monofilament cords have a smaller initial elongation than ordinary twisted cords, so that the binding force of the auxiliary reinforcement layer to the main cord reinforcement layer is further increased, and the shear strain is more effectively dispersed and suppressed. This is because the crack suppression effect can be further enhanced.

  The production method of the composite fiber (monofilament) of the present invention can be carried out by a wet heating drawing method using a core-sheath type composite spinneret with two single-screw extruders for a core material and a sheath material. The spinning temperature can be 140 to 330 ° C., preferably 160 to 220 ° C. for the sheath component, and 200 to 330 ° C., preferably 210 to 300 ° C. for the core component. The wet heating can be carried out, for example, at a wet heating apparatus 100 ° C. and a hot water bath 55-100 ° C., preferably 95-98 ° C. If it is once cooled and then reheated and stretched, the crystallization of the sheath proceeds, which is not preferable from the viewpoint of heat-fusibility. The draw ratio is preferably 1.5 times or more from the viewpoint of crystallization of the core.

  In the present invention, the fineness of the composite fiber (C), that is, the fiber thickness, is preferably in the range of 50 dtex or more and 4000 dtex or less, more preferably 500 dtex or more and 1200 dtex or less. When the fiber thickness of the reinforcing material is less than 50 dtex, the strength is low and the cord is easily broken. In particular, in the case of a tire, the fiber thickness of the reinforcing material is more preferably 500 dtex or more in order to suppress cord breakage during processing in various processes during manufacture. The fiber thickness of the reinforcing material is not particularly limited as long as it can be disposed on each member of a rubber article such as a tire, but is preferably 4000 dtex or less. This is because, in the case of monofilament cords, if the fiber thickness is large at the time of spinning, the spinning speed is slowed to reduce the economics at the time of processing, and if the yarn thickness is thick, it is wound around a winding jig such as a bobbin. This is because sometimes it becomes difficult to bend and workability is reduced. In addition, the fiber thickness in this invention means the fiber size (based on JISL0101) measured by monofilament single in the case of a monofilament.

  One feature of the monofilament cord made of the composite fiber (C) according to the present invention is that it has high adhesion to rubber even when the thickness of the single fiber is 50 dtex or more. When the fiber thickness of the composite fiber (C) is less than 50 dtex, even when the adhesive composition is not bonded, or the fiber is not fused between the fiber resin and the rubber, a problem in the close contact with the rubber hardly occurs. This is because, when the diameter of a single fiber is reduced, the stress at which the cord is cut becomes smaller than the force at which the cord peels off. Therefore, when the adhesion is evaluated by peeling or the like, the interface between the cord and the rubber is peeled off. This is because the cord is cut before. These are also referred to as so-called “fluff adhesion”, and are phenomena that can be observed at a single fiber thickness of less than 50 dtex, which is about the same as that of fluff.

In the tire of the present invention, the tensile strength at break after vulcanization of the auxiliary reinforcing layer 4 formed by rubber-covering the composite fiber is preferably 29 N / mm ² or more.

  Further, in the tire of the present invention, the composite fiber (C) can be disposed in any direction from 0 ° to 90 ° from the tire radial direction. In addition, when the orientation direction of a preferable reinforcing material is 0 ° from the direction in which the reinforcing cords of the main cord reinforcing layer that is not covered with the adhesive treatment are disposed at the end portions, peeling in the vertical direction from the cord end surfaces can be suppressed. Therefore, even if it is arranged at an angle other than that, since the vicinity of the cord end is covered, the effect of suppressing peeling of the cord end can be obtained.

  In the present invention, the number of core-sheath fibers to be driven is preferably 5 to 65 fibers / 50 mm, and more preferably 10 to 60 fibers / 50 mm. If the burying density of the core-sheath fibers is less than 5/50 mm, the effect of suppressing the occurrence of cracks may be insufficient. Moreover, when the number of core-sheath fibers to be driven exceeds 65 fibers / 50 mm, if the core-sheath fibers are close to each other or are fused to each other, the vicinity of the fiber interface tends to peel due to strain stress, which is not preferable.

  In the tire of the present invention, an auxiliary reinforcing layer is disposed adjacent to the vicinity of the cord cutting end of the main cord reinforcing layer and at least covering the cord cutting end of the adjacent main cord reinforcing layer from the inside and / or outside of the tire. The auxiliary reinforcing layer only needs to be made of a specific core-sheath fiber, and its internal structure is the same as that of a general pneumatic tire, and can be appropriately determined as desired.

  A tire 10 shown in FIG. 1 includes a pair of bead portions 5, a pair of sidewall portions 6 that extend from the pair of bead portions 5 to the outside in the tire radial direction, and a grounding portion that extends between the pair of sidewall portions 6. The tread portion 7 is formed. The illustrated tire 10 has one or more carcass plies 1 extending in a toroidal shape between bead cores 2 embedded in a pair of bead portions 5 as a skeleton, and is disposed outside the crown portion in the radial direction of the tire. One or more belt layers 3 are provided. Although not shown, an inner liner is disposed inside the carcass ply 1 in the tire radial direction, and a bead filler 8 is usually disposed outside the bead core 2 in the tire radial direction.

The width direction fragmentary sectional view which shows the other example of the pneumatic tire of this invention in FIGS.
In the tire 20 shown in FIG. 2, the auxiliary reinforcing layers 14A and 14B are adjacent to the vicinity of the cord cutting end 11a of the folded end portion of the carcass ply 11 as the main cord reinforcing layer. The carcass ply 11 is disposed so as to be sandwiched from the inside so as to extend from the cord cut end 11a of the carcass ply 11 both inside and outside in the tire radial direction. In the present invention, an auxiliary reinforcing layer may be disposed inside the tire at the cord cut end 11a as described above. Also in this case, it is possible to obtain the effect of suppressing the occurrence of cracks from the cord cut end 11a of the folded end portion of the carcass ply 11. In addition, the code | symbol 12 shows a bead core and 18 shows a bead filler.

  Further, in the tire 30 shown in FIG. 3, the auxiliary reinforcing layer 24 is adjacent to the vicinity of the cord cutting end 21a of the folded end portion of the carcass ply 21 as the main cord reinforcing layer, and the cord cutting end 21a is connected to the tire radius. It is disposed so as to be wrapped from the outside in the direction, extending inward in the tire radial direction from the cord cut end 21a of the carcass ply 21 at a position covering from the outside and inside of the tire. Also in this case, it is possible to obtain the effect of suppressing the occurrence of cracks from the cord cut end 21a of the folded end portion of the carcass ply 21. Reference numeral 22 denotes a bead core, and 28 denotes a bead filler.

  Further, in the tire 40 shown in FIG. 4, the auxiliary reinforcing layers 34A and 34B are adjacent to the vicinity of the cord cutting end 33a of the belt layer 33 as the main cord reinforcing layer, and the cord cutting end 33a is sandwiched from the outside of the tire, respectively. In this way, the belt layer 33 is disposed so as to extend both inside and outside in the tire width direction from the cord cut end 33a of the belt layer 33. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 33a of the belt layer 33 can be obtained. Reference numeral 31 denotes a carcass ply.

  Further, in the tire 50 shown in FIG. 5, the auxiliary reinforcing layer 44 is adjacent to the vicinity of a part of the cord cutting end 43a in the belt layer 43 as the main cord reinforcing layer, and the cord cutting end 43a is connected to the tire. It wraps from the outer side in the width direction, and is disposed so as to extend from the cord cut end 43a of the belt layer 43 to the inner side in the tire width direction at a position covering from the outer side and the inner side of the tire. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 43a of the belt layer 43 can be obtained. Reference numeral 41 denotes a carcass ply.

  Further, in the tire 60 shown in FIG. 6, the auxiliary reinforcing layer 54 is adjacent to the vicinity of the cord cutting end 51a of the folded end portion of the carcass ply 51 as the main cord reinforcing layer, and the cord cutting end 51a is connected to the inside of the tire. The carcass ply 51 is disposed so as to be sandwiched between the cord cutting end 51a of the carcass ply 51 so as to extend both inside and outside in the tire radial direction. In the present invention, the auxiliary reinforcing layer may be disposed inside the tire at the cord cut end 51a as described above. Also in this case, it is possible to obtain an effect of suppressing the occurrence of cracks from the cord cut end 51a of the folded end portion of the carcass ply 51. Reference numeral 52 represents a bead core, and 58 represents a bead filler.

  Furthermore, in the tire 70 shown in FIG. 7, the auxiliary reinforcing layer 64 is adjacent to the vicinity of a part of the cord cutting end 63a of the belt layer 63 as the main cord reinforcing layer, and the cord cutting end 63a is The belt layer 63 is disposed so as to extend from the cord cut end 63a of the belt layer 63 to the inner side in the tire width direction at a position covering from the outer side in the tire width direction. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 63a of the belt layer 63 can be obtained. Reference numeral 61 denotes a carcass ply.

  Furthermore, in the tire 80 shown in FIG. 8, the auxiliary reinforcing layer 74 is adjacent to the vicinity of a part of the cord cutting end 73a of the belt layer 73 as the main cord reinforcing layer, and the cord cutting end 73a is The belt layer 73 is disposed so as to extend from the cord cut end 73a of the belt layer 73 toward the inner side in the tire width direction at a position covering from the outer side in the tire width direction. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 73a of the belt layer 73 can be obtained. Reference numeral 71 denotes a carcass ply.

  Furthermore, in the tire 90 shown in FIG. 9, the auxiliary reinforcing layer 84 is adjacent to the vicinity of a part of the cord cutting end 83a of the belt layer 83 as the main cord reinforcing layer, and the cord cutting end 83a is In a position covering from the inner side in the tire width direction, the belt layer 83 is disposed so as to extend inward in the tire width direction from the cord cut end 83a. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 83a of the belt layer 83 can be obtained. Reference numeral 81 denotes a carcass ply.

  In the present invention, when there are a plurality of cord reinforcing layers, the effect of the present invention can be obtained as long as the auxiliary reinforcing layer is disposed adjacent to at least a part thereof. It is arranged on the cord reinforcement layer located on the outer side in the tire radial direction where the load of centrifugal force increases when moving, or on the cord reinforcement layer located on the outer side in the tire width direction where distortion due to stress in the tire lateral direction increases due to curves etc. Is preferred.

The present invention is not limited to the tire type, and the illustrated tire is a passenger tire, but can be applied to any tire such as a truck / bus tire or a large tire.
FIG. 10 is a cross-sectional view in one side in the width direction showing a truck / bus tire according to another example of the tire of the present invention. The illustrated tire 100 includes a tread portion 97 that forms a ground contact portion, a pair of sidewall portions 96 that extend inward in the tire radial direction continuously to both sides of the tread portion 97, and an inner periphery of each sidewall portion 96. And a bead portion 95 continuous to the side. The tread portion 97, the sidewall portion 96, and the bead portion 95 are reinforced by a carcass made of at least one toroidal shape extending from one bead portion 95 to the other bead portion 95, in the illustrated example, two carcass plies 91. Has been. Further, in the illustrated truck / bus tire 100, a bead core 92 is embedded in each of the pair of bead portions 95, and the carcass 91 is folded around the bead core 92 from the inside to the outside and locked. Further, a bead filler 98 is disposed outside the bead core 92 in the tire radial direction.

  In the tire 100 shown in FIG. 10, the auxiliary reinforcing layers 94A and 94B are adjacent to the vicinity of the cord cutting end 91a at the folded end portion of the two carcass plies 91 as the main cord reinforcing layer, and the cord cutting end 91a The carcass ply 91 is disposed so as to be wrapped from the outside in the tire radial direction so as to extend from the cord cut end 91a of the carcass ply 91 to the inside in the tire radial direction at a position covering from the outside and inside of the tire. Also in this case, it is possible to obtain the effect of suppressing the occurrence of cracks from the cord cut end 91a of the folded end portion of the carcass ply 91.

  In the tire 110 shown in FIG. 11, the auxiliary reinforcing layers 104A and 104B are disposed on the cord cut end 101a at the folded end portion of the carcass ply 101 as the main cord reinforcing layer and on the outside of the carcass ply 101 in the bead portion. A position where the cord cutting end 101a and the tire width direction outer end portion 109a are covered from the outer side in the tire radial direction and covered from the outer side and the inner side of the chafer 109 adjacent to the vicinity of the outer end portion 109a in the tire width direction. Further, the carcass ply 101 is disposed so as to extend inward in the tire radial direction from the cord cutting end 101a or the tire width direction outer end 109a. Also in this case, it is possible to obtain an effect of suppressing the occurrence of cracks from the cord cut end 101a at the folded end portion of the carcass ply 101 and the outer end portion 109a in the tire width direction of the chafer 109. Reference numeral 102 denotes a bead core, and 108 denotes a bead filler. As the chafer, for example, a nylon chafer made of nylon can be used.

  In the tire 120 shown in FIG. 12, the auxiliary reinforcing layer 114 is adjacent to the vicinity of the tire width direction outer side end portion 119a of the chafer 119 disposed outside the carcass ply 111 in the bead portion, and this tire width direction outer side. The end portion 119a is disposed so as to be wrapped from the outer side in the tire radial direction so as to extend from the outer side and the inner side of the tire so as to extend inward in the tire radial direction from the outer end portion 119a in the tire width direction. Also in this case, the effect of suppressing the occurrence of cracks from the outer end portion 119a in the tire width direction of the chafer 119 can be obtained. In addition, the code | symbol 112 shows a bead core and 118 shows a bead filler.

  In the tire 130 shown in FIG. 13, the auxiliary reinforcing layers 124A and 124B are adjacent to the vicinity of the cord cutting end 121a of the folded end portion of the two carcass plies 121 as the main cord reinforcing layer, and the cord cutting end 121a The carcass ply 121 is disposed so as to be wrapped from the outside in the tire radial direction so as to extend from the cord cutting end 121a of the carcass ply 121 to the inside in the tire radial direction at a position covering from the outside and inside of the tire. Also in this case, the effect of suppressing the occurrence of cracks from the cord cut end 121a of the folded end portion of the carcass ply 121 can be obtained. Reference numeral 122 denotes a bead core, and 128 denotes a bead filler.

  In the tire 140 shown in FIG. 14, the auxiliary reinforcing layers 134A and 134B are disposed outside the carcass ply 131 at the cord cut end 131a at the folded end portion of the carcass ply 131 as the main cord reinforcing layer and at the bead portion. A position where the cord cutting end 131a and the tire width direction outer end portion 139a are wrapped from the outer side in the tire radial direction and covered from the outer side and the inner side, adjacent to the vicinity of the tire width direction outer end portion 139a of the chafer 139. Further, the cord cutting end 131a of the carcass ply 131 or the tire width direction outer side end portion 139a is disposed so as to extend inward in the tire radial direction. Also in this case, it is possible to obtain an effect of suppressing the occurrence of cracks from the cord cut end 131a at the folded end portion of the carcass ply 131 and the outer end portion 139a in the tire width direction of the chafer 139. Reference numeral 132 denotes a bead core, and 138 denotes a bead filler.

  In the tire 150 shown in FIG. 15, the auxiliary reinforcing layer 144 is adjacent to the vicinity of the outer end portion 149a in the tire width direction of the chafer 149 disposed outside the carcass ply 141 in the bead portion. The end portion 149a is disposed so as to be wrapped from the outer side in the tire radial direction and at a position covering the outer side and the inner side of the tire so as to extend inward in the tire radial direction from the outer end portion 149a in the tire width direction. Also in this case, the effect of suppressing the occurrence of cracks from the outer end portion 149a in the tire width direction of the chafer 149 can be obtained. Reference numeral 142 denotes a bead core, and 148 denotes a bead filler.

  In the present invention, as a method for producing a composite strip in which the core-sheath fibers are embedded, first, the core-sheath fibers are arranged in parallel and covered with rubber to form a sheet-like rubber-fiber composite. Prepare (composite manufacturing step). In this step, for example, a predetermined number of core-sheath fibers are aligned in parallel and passed between rolls, and coated with rubber from above and below, or co-extruded, or fibers spun into a core-sheath shape from a nozzle It can be carried out by a method of placing and transporting on a rubber sheet moving in the horizontal direction and further covering with rubber from above. This sheet-like rubber-fiber composite includes one core-sheath fiber in the thickness direction. For example, the sheet thickness can be 0.5 mm to 1.5 mm. In this step, the number of core-sheath fibers driven into the tread rubber can be changed by appropriately adjusting the alignment interval (drive-in interval) of the core-sheath fibers.

  Next, the obtained rubber-fiber composite is cut at an arbitrary angle at which a reinforcing material is disposed as an auxiliary reinforcing layer of the tire with respect to the longitudinal direction of the core-sheath fiber, for example, perpendicularly, for example, at intervals of 20 to 1000 mm Then, the cut sheets are sequentially joined to obtain a composite strip of rubber-fiber composite (cutting step).

  Next, when the auxiliary reinforcing layer is disposed adjacent to the cord cut end of the carcass ply, in the primary molding of the green tire, the obtained composite strip is used as the carcass folded portion in the cylindrical molded body of the carcass ply. Adjacent to the vicinity of the cord cut end of the carcass ply, the cord cut end is pasted so as to cover the entire circumference from the outer side of the tire (paste step). Next, in the secondary molding of the green tire, the composite strip is expanded together with the carcass ply to a predetermined outer diameter (expansion step) to produce a molded green tire.

  Further, when the auxiliary reinforcing layer is disposed adjacent to the cord cut end of the belt layer, it is not particularly limited. For example, in the secondary molding of the green tire, the composite strip is placed near the cord cut end of the belt layer. A molded green tire can be manufactured, for example, by adhering and arranging adjacent to each other and covering the rubber composition to be a tread portion thereon. The case where the auxiliary reinforcing layer is disposed in the vicinity of the outer end portion of the chafer in the tire width direction can be performed in accordance with these.

  The tire of the present invention is produced by vulcanizing the green tire obtained as described above at a vulcanization temperature of 140 ° C. to 190 ° C. for 3 to 50 minutes according to a conventional method (vulcanization step). Can do.

Hereinafter, the present invention will be described in more detail with reference to examples.
As a reinforcing cord of the auxiliary reinforcing layer, a composite fiber (C) using a material described in Table 1 below as a sheath material and a core material, which was dried using a vacuum dryer, was used.

1) Manufacture of test fiber Spinning temperatures shown in each table using two single-screw extruders of 50 mm for core material and sheath material using the materials shown in Table 1 as the core component and sheath component. Then, using a core-sheath type composite spinneret with a caliber of 1.3 mm, the discharge rate is adjusted at about 5.9 g / min so that the sheath-core ratio is 35:65 by mass ratio, and the spinning speed is 60 m. The melt-spinning was performed at a rate of 1.7 times in a hot water bath at 95 ° C. to obtain a core-sheath type composite monofilament having a fineness of 550 dtex.

2) Production of rubber-fiber composite strips Core-sheath type composite fibers (fineness: 550 dtex) obtained by using the core and sheath materials shown in Tables 2 and 3 below were aligned in parallel. A rubber-fiber composite with a thickness of 0.60 mm was manufactured by coating with rubber at a driving number of 42/50 mm. This rubber-fiber composite is defeated in accordance with the orientation angle and width of the reinforcing layer shown in the table, and the defeated composite strip is bonded in the lateral direction without any gaps, and the rubber-fiber composite treat is formed. Obtained.

3) Manufacture of test tires
i) Manufacture of a tire in which an auxiliary reinforcing layer is disposed adjacent to the cord cut end of the carcass ply In the primary molding of a green tire, the composite treat is 30 mm wide so as to have an angle described in the table, Adjacent to the carcass ply in the vicinity of the cord cutting end, and pasting so that at least the cord cutting end covers the entire circumference from the outside of the tire so that the cord cutting end position is at the center of the strip width (FIG. 1), green In the secondary molding of a tire, a green tire in which a composite strip is expanded to a predetermined outer diameter together with a carcass ply is vulcanized at a vulcanization temperature of 188 ° C. and a vulcanization time of 18 minutes. 1-3 test tires were produced. In this test tire, the distance in the thickness direction of the carcass ply between the carcass ply and the auxiliary reinforcing layer was 0.8 mm.
The orientation angle of the auxiliary reinforcing layer is an angle formed by the tire radial direction and the reinforcing material.

ii) Manufacture of a tire in which an auxiliary reinforcing layer is disposed adjacent to the cord cut portion of the belt layer In secondary molding of a green tire, the composite strip is formed into a belt layer having a width of 25 mm so as to have an angle described in the table. Adjacent to the vicinity of the cord cutting end (on the first belt, on the second belt) and disposed so as to be positioned at the center of the strip width over the entire circumference in the tire circumferential direction (FIG. 8). Thereafter, a rubber composition serving as a tread portion was coated thereon and expanded to a predetermined outer diameter together with a carcass ply to produce a molded green tire. The auxiliary reinforcing layer end on the outer side in the tire radial direction was disposed so as to be 7 mm outside from the outer end of one belt ply.
This green tire was vulcanized at a vulcanization temperature of 188 ° C. and a vulcanization time of 18 minutes to produce test tires of Example 8 and Comparative Example 4. In this test tire, the distance in the thickness direction of the belt layer between the belt layer and the auxiliary reinforcing layer was 0.85 mm.
The orientation angle of the auxiliary reinforcing layer is an angle formed by the tire width direction and the reinforcing material.

(Drum running durability)
About the test tires (tire size: 205 / 60R15) obtained in Examples 1 to 7 and Comparative Examples 1 to 3, the filling air pressure to the tire was set to 200 kPa, and mounted on a 6.0 J × 15 inch rim, A load of 999 kg, which is 1.8 times the load capacity of 555 kg of the tire size load defined by JATMA YEAR BOOK (2014, Japan Automobile Tire Association Standard), is applied and the speed is 60 km / h. The distance until it was moved and destroyed was measured and compared. The result is shown as a life index with the travel distance of Comparative Example 1 as 100. The larger the index value, the better the durability and the better.

(Belt end durability evaluation)
The obtained tires of Example 8 and Comparative Example 4 (tire size: 205 / 60R15) were subjected to belt end durability evaluation by pressing the tire against a steel drum having a diameter of 3 m and rotating the tire at a high speed. It was. The tire was pressed with a camber angle of -1 degree, a slip angle of 0 degree, and a load of 8 kN. The tire was mounted on a 6.0 J × 15 inch rim, and the tire internal pressure was 180 kPa, which was lower than the specified internal pressure of 220 kPa. The reason for setting the tire internal pressure to be lower than the specified internal pressure is to increase the amount of deflection of the tire and promote the failure of the tire. After running for 100 hours at a speed of 130 km / h, stop the drum, then disassemble the tire, and measure the length of cracks from the two belt ply ends at 64 locations on the belt circumference on both sides. The average value was calculated and shown as an index with the crack length of Comparative Example 1 as 100. In addition, the temperature around the drum was controlled at 10 ° C., and the wind at a wind speed of 10 m / s was continuously blown toward the tire to prevent extreme heat generation of the tire and to reproduce the actual running state as much as possible. . The smaller the index value, the smaller the crack length and the better.
The evaluation results are shown in Table 2 and Table 3 below.

  As shown in the above table, according to the present invention, the occurrence of cracks from the cut end of the cord of the carcass ply as the main cord reinforcing layer or the belt layer is suppressed without causing a problem due to the auxiliary reinforcing layer itself. As a result, it has become possible to realize a pneumatic tire with improved durability compared to the prior art.

1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111, 121, 131, 141 Carcass plies 1a, 11a, 21a, 33a, 43a, 51a, 63a, 73a, 83a, 91a , 101a, 121a, 131a Cord cut ends 2, 12, 22, 52, 92, 102, 112, 122, 132, 142 Bead cores 3, 33, 43, 63, 73, 83, 101, 111 Belt layers 4, 14A, 14B, 24, 34A, 34B, 44, 54, 64, 74, 84, 94A, 94B, 104A, 104B, 114, 124A, 124B, 134A, 134B, 144 Auxiliary reinforcing layer 5, 95 Bead portion 6, 96 Side wall Part 7, 97 Tread part 8, 18, 28, 58, 98, 108, 118, 128, 138, 148 B Filler 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 Pneumatic tire 109, 119, 139, 149 Chafer 109a, 119a, 139a, 149a Fur outer width direction end portion 200 of core Fur sheath cord 221 Core portion 222 Sheath portion

Claims (14)

One or more carcass plies formed by arranging cutting cords in parallel are disposed on a toroidal with their side portions wrapped around a bead core, and the cutting cords are arranged in parallel on the outer side of the crown portion of the carcass ply in the tire radial direction. A pneumatic tire in which one or more belt layers are disposed,
As a main cord reinforcing layer, near the cord cutting end of at least one of the carcass ply and the belt layer, or near the outer end in the tire width direction of the chafer disposed outside the carcass ply in the bead portion. An auxiliary reinforcing layer is disposed adjacently, and the auxiliary reinforcing layer is at least the cord cut end of the adjacent main cord reinforcing layer or the vicinity of the outer end in the tire width direction of the chafer inside the tire. And / or disposed at a position covering from the outside,
Resin material (B) including an olefin polymer (D) having a core portion made of a high melting point resin (A) having a melting point of 150 ° C. or higher and a sheath portion having a melting point not higher than the tire vulcanization temperature. A pneumatic tire comprising a core-sheath type composite fiber (C) made of   The pneumatic tire according to claim 1, wherein a distance in a thickness direction of the main cord reinforcing layer between the main cord reinforcing layer and the auxiliary reinforcing layer is 3 mm or less.   The olefin polymer (D) includes a propylene-α olefin copolymer (H), a propylene-nonconjugated diene copolymer (I), an unsaturated carboxylic acid or an anhydride monomer thereof. The ionomer (J) having a degree of neutralization with a metal salt of the copolymer of 20% or more and one or more components selected from the group consisting of olefin homopolymers (K). The described pneumatic tire.   The resin material (B) is a styrene elastomer (L) containing a single molecular chain in which the olefin polymer (D) and a styrene monomer are mainly continuously arranged, and a vulcanization accelerator (M). The pneumatic tire as described in any one of Claims 1-3 containing 1 or more types chosen from vulcanization | cure acceleration | stimulation adjuvant (N) and a filler (O).   The pneumatic tire according to claim 3 or 4, wherein the propylene-α-olefin copolymer (H) is a propylene-ethylene random copolymer and / or a propylene-ethylene-butene random copolymer.   The pneumatic tire according to any one of claims 3 to 5, wherein the ionomer (J) is an ionomer of an ethylene / ethylenically unsaturated carboxylic acid copolymer.   The pneumatic tire according to any one of claims 3 to 6, wherein the olefin homopolymer (K) is a polyethylene polymer and / or a polypropylene polymer.   The pneumatic tire according to any one of claims 4 to 7, wherein the styrene elastomer (L) includes a styrene block copolymer, a hydrogenated product thereof, or a modified product thereof.   The pneumatic tire according to claim 8, wherein the styrene-based elastomer (L) is a styrene-butylene-butadiene-styrene copolymer.   The high-melting point resin (A) includes a polymer selected from a polyolefin resin (P) having a melting point of 150 ° C or higher, a polyester resin (Q), and a polyamide resin (R). A pneumatic tire according to any one of the above.   The pneumatic tire according to any one of claims 1 to 10, wherein the fineness of the composite fiber (C) is 50 to 4000 dtex.   The pneumatic tire according to any one of claims 1 to 11, wherein the number of driving of the composite fiber (C) is 5 to 65 pieces / 50 mm. A method of manufacturing the pneumatic tire according to claim 1,
The composite fiber (C) is arranged in parallel and covered with a rubber to produce a sheet-like rubber-fiber composite, and a composite is prepared by cutting the rubber-fiber composite obtained. In the cutting step of obtaining a body strip and in the primary molding of a green tire, the obtained composite strip is adjacent to the vicinity of the cord cutting end of the carcass ply, which is a carcass folded portion in the cylindrical molded body of the carcass ply Then, an affixing step for affixing at least the cord cut end to cover the entire circumference from the outer side of the tire, and an expansion step for expanding the composite strip together with the carcass ply to a predetermined outer diameter in the secondary molding of the green tire A method for manufacturing a pneumatic tire, comprising: A sheet-like rubber-fiber composite having a thickness of 0.5 to 1.5 mm is prepared in the composite preparation step, and the obtained rubber-fiber composite is cut at intervals of 20 to 1000 mm in the cutting step. Item 14. A method for producing a pneumatic tire according to Item 13.