WO2020080442A1

WO2020080442A1 - Elastomer-metal cord composite body and tire using same

Info

Publication number: WO2020080442A1
Application number: PCT/JP2019/040763
Authority: WO
Inventors: 一樹上村; 英幸額賀
Original assignee: 株式会社ブリヂストン
Priority date: 2018-10-17
Filing date: 2019-10-16
Publication date: 2020-04-23
Also published as: JPWO2020080442A1

Abstract

The present invention provides: an elastomer-metal cord composite body which is capable of improving various properties of a tire such as steering stability, crack growth resistance and low loss characteristics; and a tire which uses this elastomer-metal cord composite body. One embodiment of the present invention is an elastomer-metal cord composite body 10 which is obtained by covering, with an elastomer 3, a metal cord 2 that is composed of a bundle of a plurality of metal filaments that are arranged in a row without being twisted. At least one pair of adjacent metal filaments that are different from each other in at least one of patterning amount and patterning pitch is present in the metal cord; and the ratio of the 200% modulus value (M200) to the 50% modulus value (M50) of the elastomer, namely M200/M50 is 5.0 or less.

Description

Elastomer-metal cord composite and tire using the same

TECHNICAL FIELD The present invention relates to an elastomer-metal cord composite and a tire using the same, and more specifically, an elastomer-metal cord composite obtained by coating a metal cord composed of a bundle of metal filaments aligned without twisting with an elastomer, And a tire using the same.

Generally, inside the tire where strength is required, a carcass including reinforcing cords embedded along the meridian direction of the ring-shaped tire body is arranged, and a belt layer is arranged on the tire radial outside of the carcass. To be done. This belt layer is usually formed by using an elastomer-metal cord composite obtained by coating a metal cord such as steel with an elastomer, and imparts load resistance, traction resistance and the like to the tire.

In recent years, there has been an increasing demand for reducing the weight of tires in order to improve the fuel efficiency of automobiles. As a means of reducing the weight of tires, metal cords for belt reinforcement have attracted attention, and cords for belts have not been twisted with metal filaments. Many technologies used as are published. For example, in Patent Document 1, in order to improve lightness and durability, thin metal filaments having high tensile strength are aligned in parallel without twisting to form a metal filament bundle, which is placed in a coated rubber. A tire has been proposed in which a belt layer is formed by at least two belt plies arranged in the width direction.

In this way, by forming bundles of metal monofilaments and coating them with an elastomer to form cords, the weight of the belt is reduced by gauge, and the belt edge separation (BES) resistance is improved by ensuring the distance between the monofilament bundles. Can be compatible with both. However, in such a cord, a non-penetrating region (non-elastomer coating region) of the elastomer continuous in the longitudinal direction is generated on the side surface portion of the adjacent metal filaments, and the metal filaments are displaced from each other during rolling of the tire. However, since the in-plane rigidity (rigidity in the tire ground contact surface) is reduced, improvement in steering stability cannot be obtained.

Also, in order to improve the fuel efficiency of automobiles, it is effective to reduce the rolling resistance of tires, and from this viewpoint, there is an increasing demand for improving the low loss property of the elastomer for coating the belt layer. On the other hand, the elastomer for coating the belt layer is required to have high durability, especially high crack growth resistance.

JP 2001-334810A

However, in Patent Document 1, although BES resistance is examined, steering stability, low loss, and crack growth resistance are not examined. Therefore, it has been required to realize a reinforcing material that can satisfy these required performances.

Therefore, an object of the present invention is to coat a plurality of metal filaments without twisting the metal cords made of a bundle of metal cords covered with an elastomer, steering stability and crack growth resistance, low loss of tire and the like. An object of the present invention is to provide an elastomer-metal cord composite capable of improving various performances, and a tire using the same.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using a bundle of metal filaments having the following structure and using an elastomer that satisfies the following predetermined physical properties. Has been completed.

That is, the elastomer-metal cord composite of the present invention is an elastomer-metal cord composite in which a metal cord composed of a bundle in which a plurality of metal filaments are not twisted and aligned in a row is coated with an elastomer.
In the metal cord, there is at least one pair of adjacent metal filaments having different at least one of a molding amount and a molding pitch, and a 200% modulus with respect to a 50% modulus value (M50) of the elastomer. The ratio M200 / M50 of the value (M200) is 5.0 or less.

Here, FIG. 1 is an explanatory diagram of the metal filament showing the definition of the metal filament forming amount h and the forming pitch p, and the forming amount h refers to the width of fluctuation that does not include the wire diameter of the metal filament 1. The amount h of the metal filament 1 to be imprinted is measured by projecting the metal filament 1 after imprinting with a projector and projecting a projected image of the metal filament on a screen or the like.

Also, the 50% modulus is the tensile stress at the elongation of the elastomer of 50%, and the 200% modulus is the tensile stress of the elastomer at the elongation of 200%. These values can be measured in accordance with JIS K 6251 (2010) after the rubber composition is vulcanized into a vulcanized rubber when the elastomer is a rubber composition. The conditions for vulcanizing the rubber composition are not particularly limited, and can be appropriately performed under known vulcanization conditions.

In the elastomer-metal cord composite of the present invention, it is preferable that the metal filament in the metal cord is imprinted in the width direction of the metal cord. Further, in the elastomer-metal cord composite of the present invention, it is preferable that the elastomer coverage of the adjacent metal filaments on the side surface in the width direction of the metal cord is 10% or more per unit length.

Furthermore, in the elastomer-metal cord composite of the present invention, at least one of the metal filaments in the metal cord is preferably a substantially straight metal filament. Furthermore, in the elastomer-metal cord composite of the present invention, it is preferable that the straight metal filaments and the patterned metal filaments are alternately arranged. Furthermore, in the elastomer-metal cord composite of the present invention, the metal filaments arranged at both ends of the metal cord are preferably the straight metal filaments.

Furthermore, in the elastomer-metal cord composite of the present invention, the metal filament is two-dimensionally shaped, and the metal filament has an amount of 0.03 mm or more and 0.30 mm or less. It is preferable that the patterning pitch of is 2 mm or more and 30 mm or less. Moreover, the elastomer of the present invention - In the metal cord composite, the elastomer is a rubber component, and carbon black DBP absorption is less than 50 cm ^3/100 g or more 100 cm ^3/100 g, a phenol resin, a methylene donor It is preferably composed of a rubber composition containing

Here, in the present invention, the elastomer coverage means, for example, when rubber is used as the elastomer and steel cord is used as the metal cord, the rubber cord obtained by coating the steel cord with rubber and vulcanizing is obtained. The steel cord is pulled out from the composite, and the length of the side surface of the steel filament in the width direction of the metal cord, which is covered with the rubber that has penetrated into the gap between the steel filaments that make up the steel cord, is measured and calculated based on the following formula It means the average of the values.
Elastomer coverage = (rubber coating length / sample length) x 100 (%)
The same calculation can be performed when an elastomer other than rubber is used as the elastomer and when a metal cord other than the steel cord is used as the metal cord. Further, in the elastomer-metal cord composite of the present invention, a straight metal filament refers to a metal filament that is not intentionally modeled and is substantially unmolded.

The tire of the present invention is characterized by using the elastomer-metal cord composite of the present invention.

According to the present invention, a metal cord made of a bundle in which a plurality of metal filaments are aligned without being twisted is coated with an elastomer, and various tire performances such as steering stability, crack growth resistance, and low loss property are provided. It was possible to provide an elastomer-metal cord composite capable of improving the above, and a tire using the same.

It is explanatory drawing of a metal filament which shows the definition of the amount h and the pitch p of a metal filament. FIG. 3 is a partial cross-sectional view in the width direction of the elastomer-metal cord composite according to the preferred embodiment of the present invention. FIG. 3 is a schematic plan view of a metal cord according to an elastomer-metal cord composite of a preferred embodiment of the present invention. FIG. 3 is a schematic cross-sectional view in the width direction of a metal cord according to an elastomer-metal cord composite of a preferred embodiment of the present invention. FIG. 5 is a schematic cross-sectional view in the width direction of a metal cord according to an elastomer-metal cord composite of another preferred embodiment of the present invention. 1 is a schematic one-sided cross-sectional view of a tire according to a preferred embodiment of the present invention.

Hereinafter, the elastomer-metal cord composite of the present invention will be described in detail with reference to the drawings. FIG. 2 is a partial cross-sectional view in the width direction of an elastomer-metal cord composite according to a preferred embodiment of the present invention, and FIG. 3 is an elastomer-metal cord composite of a preferred embodiment of the present invention. FIG. 4 is a schematic plan view of the metal cord relating to the body, and FIG. 4 is a schematic cross-sectional view in the width direction of the metal cord relating to the elastomer-metal cord composite of the preferred embodiment of the present invention.

The elastomer-metal cord composite 10 of the present invention has a plurality of metal filaments 1 covered with an elastomer 3 on a metal cord 2 formed of a bundle in which the metal filaments 1 are not twisted and aligned in a line. The number of the metal filaments 1 is preferably 2 or more, more preferably 5 or more, preferably 20 or less, more preferably 18 or less, further preferably 15 or less, particularly preferably The metal cord 2 is composed of a bundle of 12 or less. In the illustrated example, five metal filaments 1 are aligned without being twisted to form a metal cord 2.

In the elastomer-metal cord composite 10 of the present invention, the metal cord 2 has at least one pair of adjacent metal filaments 1 having different at least one of the molding amount and the molding pitch. As described above, in the elastomer-metal cord composite 10 of the present invention, by adjoining the metal filaments 1 having different imprinting amounts or imposing pitches, the phases of the two do not match each other. The elastomer coating region is eliminated, and the elastomer can be sufficiently permeated between the adjacent metal filaments 1. As a result, the steel cord can be out-of-plane deformed at the time of compression input, and the steel cord can be prevented from being broken. In addition, since there is no water passage for water when the tire is damaged when it is inundated, the corrosion resistance is greatly improved. Further, since the adjacent metal filaments 1 are constrained by the elastomer, by using the elastomer-metal cord composite 10 of the present invention as a cord for a belt of a tire, the adjacent metal filaments can be mutually protected even when the tire is rolling. As a result, the in-plane rigidity of the belt can be improved and steering stability can be improved.

In addition, the inventors of the present invention have conducted extensive studies on compatibility between low loss property and crack growth resistance property, and as a result, 200% modulus value (50% modulus value (M50)) of the elastomer 3 covering the metal cord 2 ( It was noted that the ratio M200 / M50 of M200) is highly related to the crack growth resistance. As a result of further study, the present inventors have made it possible to achieve both low loss property and crack propagation resistance at a higher level than in the prior art by setting the ratio M200 / M50 to a specific value or less. I found that. That is, in the elastomer-metal cord composite 10 of the present invention, the ratio M200 / M50 of the 200% modulus value to the 50% modulus value of the elastomer 3 covering the metal cord 2 is 5.0 or less.

Therefore, in the elastomer-metal cord composite 10 of the present invention, by using the metal cord 2 including the pair of the predetermined metal filaments 1 and the elastomer 3 having the predetermined physical property values in combination, a tire is obtained. When applied, it is possible to improve not only steering stability but also crack propagation resistance and low loss property.

First, the metal cord 2 according to the elastomer-metal cord composite 10 of the present invention will be described.

In the metal cord 2 according to the present invention, adjacent metal filaments 1 are different from each other in at least one of the molding amount and the molding pitch, particularly the molding amount and the molding pitch in the direction perpendicular to the extending direction of the metal filament 1. At least one pair of each other is included. In particular, at least 50% or more of the pair of metal filaments 1 are different from each other in at least one of the amount and pitch of the metal filaments 1 adjacent to each other in the direction perpendicular to the extending direction of the metal filaments 1. Is preferred. In the illustrated example, the typed metal filaments 1a and the non-typed metal filaments 1b (typed amount 0 mm, type pitch ∞ mm) are alternately arranged, but different typed metal filaments are alternately arranged. Alternatively, metal filaments having different embossing pitches may be alternately arranged. Preferably, the arrangement of the metal filaments that make up the bundle is a straight metal filament with both sides unshaped.

In the present invention, the existence of continuous non-elastomeric coating regions between adjacent metal filaments is eliminated, corrosion resistance is ensured, and the in-plane rigidity of the belt is improved and the steering stability is improved. In order to obtain the above, the elastomer coverage on the side surface in the width direction of the metal cord 2 of the adjacent metal filaments 1 is preferably 10% or more per unit length, more preferably 20% or more. The coating is more preferably 50% or more, and particularly preferably 80% or more. Most preferably, it is in a state of being covered by 90% or more.

In the elastomer-metal cord composite 10 of the present invention, the metal filament 1 may be shaped in a zigzag shape or a wavy two-dimensional shape as illustrated, or in a spiral three-dimensional shape. However, from the viewpoint of weight reduction, it is preferable that the metal filaments 1 do not overlap each other in the thickness direction of the metal cord 2.

In the elastomer-metal cord composite 10 of the present invention, if the amount of the metal filament 1 imprinted is too large, the distance w between the metal cords 2 in the elastomer-metal cord composite 10 becomes short, and the elastomer-metal of the present invention When the cord composite body 10 is used as a belt, the strength of the belt is reduced. Therefore, in the case of two-dimensional patterning, the mold amount of the metal filament 1 is preferably 0.03 mm or more and 0.30 mm or less. When the imprinting amount is 0.30 mm or less, the strength of the elastomer-metal cord composite can be secured, and the effects of the present invention can be sufficiently obtained. In particular, from the viewpoint of the distance w between the metal cords 2 and the strength of the metal filament 1, when the metal filament 1 is two-dimensionally molded, the molding amount is preferably 0.03 mm or more and 0.30 mm or less, and more preferably 0. It is 0.03 mm or more and 0.25 mm or less, and most preferably 0.03 mm or more and 0.20 mm or less. Further, in the case of two-dimensional molding, the molding pitch of the metal filament 1 is preferably 2 mm or more and 30 mm or less, more preferably 2 mm or more and 20 mm or less, and most preferably 3 mm or more and 15 mm or less. By setting the mold pitch of the metal filaments 1 to 2 mm or more, it is possible to suppress a decrease in filament strength and an increase in cord weight.

In the case of three-dimensional molding, the molding amount of the metal filament 1 is preferably 0.10 mm or more and 0.50 mm or less, more preferably 0.20 mm or more and 0.30 mm or less. By setting the mold amount to 0.50 mm or less, it is possible to suppress the decrease in the strength of the elastomer-metal cord composite and obtain the effects of the present invention sufficiently. In the case of three-dimensional molding, the molding pitch of the metal filament 1 is preferably 5 mm or more, more preferably 8 mm or more and 20 mm or less.

In addition, in the metal cord 2 shown in FIGS. 3 and 4, the metal filament 1a that is shaped is shaped in the width direction of the metal cord 2, but in the elastomer-metal cord composite 10 of the present invention, The molding direction of the metal filament 1 may be inclined with respect to the width direction of the metal cord 2. FIG. 5 is a schematic cross-sectional view in the width direction of the metal cord according to the elastomer-metal cord composite of another preferred embodiment of the present invention. Even with such a structure, rubber can be sufficiently permeated between the adjacent metal filaments 1, and the effect of the present invention can be obtained. However, in the elastomer-metal cord composite 10 of the present invention, from the viewpoint of lightness, it is possible to make the elastomer-metal cord composite thinner when the molding directions of the adjacent metal filaments 1 are in the width direction of the metal cord 2. It is preferable because it is possible.

Further, in the elastomer-metal cord composite 10 of the present invention, it is preferable that at least one of the metal filaments 1 in the metal cord 2 is a substantially straight metal filament. As shown in FIGS. 3 and 4, when the unmolded straight metal filament 1b and the molded metal filament 1a are adjacent to each other, the phases of the two do not match, so that they are not in point contact with each other. Become. Therefore, since the amount of the elastomer penetrating between the

metal filaments

1a and 1b is large, the elastomer coverage of the

adjacent metal filaments

1a and 1b on the side surface in the width direction of the metal cord 2 is high, and the non-elastomer coating region varies. Can be suppressed to a minimum, and the effects of the present invention can be satisfactorily obtained.

Further, in the elastomer-metal cord composite 10 of the present invention, the metal filaments 1 arranged at both ends of the metal cord 2 are straight metal filaments, whereby the distance w between the adjacent metal cords 2 in the elastomer is increased. Since it can be widened, the durability can be improved. More preferably, as shown in FIG. 3 and the like, straight metal filaments 1b that are not shaped and metal filaments 1a that are shaped are alternately arranged.

In the elastomer-metal cord composite 10 of the present invention, the metal filament 1 is generally a steel, that is, a linear wire containing iron as a main component (the mass of iron is more than 50 mass% based on the total mass of the metal filament). It means a metal, and may be composed only of iron, or may contain a metal other than iron, such as zinc, copper, aluminum or tin.

Further, in the elastomer-metal cord composite 10 of the present invention, the surface state of the metal filament 1 is not particularly limited, but for example, the following forms can be adopted. That is, as the metal filament 1, the N atom on the surface is 2 atom% or more and 60 atom% or less, and the Cu / Zn ratio on the surface is 1 or more and 4 or less. In addition, as the metal filament 1, the amount of phosphorus contained as an oxide in the outermost layer of the filament up to 5 nm inward in the radial direction of the filament from the filament surface is 7.0 atom% in the ratio of the total amount excluding the amount of C. The following cases may be mentioned.

Furthermore, in the elastomer-metal cord composite 10 of the present invention, the surface of the metal filament 1 may be plated. The type of plating is not particularly limited, and examples thereof include zinc (Zn) plating, copper (Cu) plating, tin (Sn) plating, brass (copper-zinc (Cu-Zn)) plating, and bronze (copper-tin ( In addition to Cu-Sn)) plating and the like, there are ternary plating such as copper-zinc-tin (Cu-Zn-Sn) plating and copper-zinc-cobalt (Cu-Zn-Co) plating. Among these, brass plating and copper-zinc-cobalt plating are preferable. This is because the brass-plated metal filament has excellent adhesion to rubber. In brass plating, the ratio of copper and zinc (copper: zinc) is usually 60 to 70:30 to 40 on a mass basis, and in copper-zinc-cobalt plating, copper is usually 60 to 75 mass%, Cobalt is 0.5 to 10 mass%. The thickness of the plating layer is generally 100 nm or more and 300 nm or less.

Further, in the elastomer-metal cord composite 10 of the present invention, the wire diameter, tensile strength, and cross-sectional shape of the metal filament 1 are not particularly limited. For example, the wire diameter of the metal filament 1 can be 0.15 mm or more and 0.40 mm or less. As the metal filament 1, one having a tensile strength of 2500 MPa (250 kg / mm ² ) or more can be used. Furthermore, the cross-sectional shape of the metal filament 1 in the width direction is not particularly limited, and may be an elliptical shape, a rectangular shape, a triangular shape, a polygonal shape, or the like, but a circular shape is preferable. In the elastomer-metal cord composite 10 of the present invention, a wrapping filament (spiral filament) may be used when the bundle of the metal filaments 1 forming the metal cord 2 needs to be constrained.

Next, the elastomer 3 covering the metal cord 2 in the elastomer-metal cord composite 10 of the present invention will be described.

The elastomer 3 used in the elastomer-metal cord composite 10 of the present invention may be one having a ratio M200 / M50 of 200% modulus value (M200) to 50% modulus value (M50) of 5.0 or less. There is no particular limitation, and a rubber composition or the like conventionally used for coating a metal cord can be used.

The above M50 is a parameter related to the elasticity of the elastomer in the low strain region. Therefore, M50 needs to be as high as possible in order to suppress the deformation of the belt portion of the tire. For this purpose, for example, in the rubber composition, it is considered that the phenol resin and the methylene donor described later are contained while adjusting the type and the content of carbon black described below. On the other hand, the M200 is a parameter related to the elasticity of the elastomer in the high strain range. Therefore, from the viewpoint of suppressing crack growth, M200 needs to have a low value in order to reduce the concentration of stress at the crack tip. For this purpose, for example, in a rubber composition, it is possible to adjust the kind and content of carbon black described later. Then, by setting the ratio of the size of the M200 to the size of the M50 to 5.0 or less (M200 / M50 ≦ 5.0), an elastomer capable of exhibiting excellent low loss property and crack growth resistance. Can be realized. From the same viewpoint, the ratio M200 / M50 is preferably 4.8 or less, and more preferably 4.5 or less.

The specific numerical range of M50 and M200 of the elastomer 3 is not particularly limited, but from the viewpoint of realizing low loss property and crack growth resistance at a higher level, M50 is 1.6 MPa or more and M200 is M200. Is preferably 10.5 MPa or less, more preferably M50 is 1.8 MPa or more and M200 is 9.0 MPa or less.

As the elastomer 3, specifically, a rubber composition or the like which has been conventionally used for coating a metal cord can be used. Examples of the main component of the elastomer 3 include natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR, high cis BR and low cis BR), nitrile rubber. (NBR), hydrogenated NBR, hydrogenated SBR and other diene rubbers and hydrogenated products thereof, ethylene propylene rubber (EPDM, EPM), maleic acid-modified ethylene propylene rubber (M-EPM), butyl rubber (IIR), isobutylene Aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), olefin rubber such as ionomer, Br-IIR, CI-IIR, bromide of isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (CR), hydrin rubber (CHR), chlorosulfone Halogen-containing rubber such as polyethylene rubber (CSM), chlorinated polyethylene rubber (CM), maleic acid modified chlorinated polyethylene rubber (M-CM), silicone rubber such as methyl vinyl silicone rubber, dimethyl silicone rubber and methylphenyl vinyl silicone rubber. , Sulfur-containing rubber such as polysulfide rubber, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicon rubber, fluorine-containing phosphazene rubber and other fluorine rubber, styrene-based elastomer, olefin-based rubber Thermoplastic elastomers such as elastomers, ester elastomers, urethane elastomers and polyamide elastomers can be preferably used. These may be used alone or in combination of two or more. In addition to the above main components, the elastomer 3 contains, in addition to the above main components, sulfur, vulcanization accelerators, carbon black, antioxidants, zinc oxide, stearic acid, etc. which are commonly used in rubber products such as tires and conveyor belts. Can be appropriately mixed.

Elastomers of the present invention - as the elastomer 3 used for the metal cord composite 10, in particular, a rubber component, and carbon black DBP absorption is less than 50 cm ^3/100 g or more 100 cm ^3/100 g, a phenol resin, a methylene donor It is preferable to use a rubber composition containing the body. With such a composition, it becomes easy to realize the predetermined modulus ratio M200 / M50. Such a rubber composition will be described below.

(Rubber component)
Regarding the rubber component, from the viewpoint that excellent crack growth resistance and abrasion resistance can be obtained, natural rubber or a diene-based synthetic rubber is used alone, or a combination of a natural rubber and a diene-based synthetic rubber is used. Can be included. Further, the rubber component may be composed of only the above-mentioned diene rubber, but may also contain a rubber other than the diene rubber as long as the object of the present invention is not impaired. The content of the diene rubber in the rubber component is preferably 30% by mass or more, more preferably 40% by mass or more, and 50% by mass from the viewpoint that excellent crack growth resistance can be obtained. % Or more is more preferable.

Here, among the above, as the diene synthetic rubber, polybutadiene rubber (BR), isoprene rubber (IR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber ( NBR) and the like. Further, examples of the non-diene rubber include ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber (IIR) and the like. In addition, about these rubber components, you may use individually by 1 type and may be used as a blend of 2 or more types. Further, these rubbers may be modified with a modifying group.

(Carbon black)
For carbon black, DBP (dibutyl phthalate) absorption amount can be used are as follows 50 cm ^3/100 g or more 100 cm ^3/100 g. By using carbon black having a DBP absorption amount within the above range and a low structure, it is possible to achieve both the reinforcing property of the rubber composition and appropriate flexibility, and to obtain excellent crack growth resistance. it can. The DBP absorption is set to be lower than or equal 100 cm ^3/100 g, by reducing the structure, moderately suppressed reinforcement of the rubber composition, to ensure flexibility, to obtain a sufficient resistance to crack growth resistance it can. DBP absorption of carbon black is ^preferably 90cm 3/100 g or ^less, more preferably 80 cm 3/100 g or less.

Note that the structure of carbon black is the size of the structure (aggregate of carbon black particles) formed as a result of fusion and connection of spherical carbon black particles. Also, the DBP absorption amount of carbon black is the amount of DBP (dibutyl phthalate) absorbed by 100 g of carbon black, and can be measured in accordance with JIS K 6217-4 (2008).

The carbon black has a nitrogen adsorption specific surface area (N ₂ SA) of preferably 70 m ² / g or more and 90 m ² / g or less, more preferably 75 m ² / g or more and 85 m ² / g or less. . As a result, the structure of carbon black can be further optimized, and thus low loss and crack growth resistance can be further improved. The nitrogen adsorption specific surface area can be measured by a single point method according to ISO 4652-1. For example, after degassed carbon black is immersed in liquid nitrogen, the surface of carbon black is equilibrated. The specific surface area (m ² / g) can be calculated from the measured value by measuring the amount of nitrogen adsorbed on.

Further, the kind of the carbon black is not particularly limited except that it has the above DBP absorption amount. For example, any hard carbon manufactured by the oil furnace method can be used. Among these, it is preferable to use HAF grade carbon black from the viewpoint of realizing more excellent low loss property and crack growth resistance.

The content of carbon black is preferably 35 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the rubber component. When the content of carbon black is 35 parts by mass or more with respect to 100 parts by mass of the rubber component, high reinforcing property and crack growth resistance can be obtained, and when it is 45 parts by mass or less, low content can be obtained. It is possible to further improve the loss property.

(Phenolic resin)
In the rubber composition suitable as the elastomer 3 used for the elastomer-metal cord composite 10 of the present invention, the 50% modulus value (M50) can be improved by including the phenol resin together with the methylene donor described later. While maintaining the excellent low loss property, the reinforcing property of the rubber composition can be improved and the excellent crack propagation resistance can be realized.

Here, the phenol resin is not particularly limited, and can be appropriately selected according to the required performance. Examples thereof include those produced by subjecting phenols such as phenol, cresol, resorcin, tert-butylphenol or a mixture thereof to formaldehyde and condensation reaction in the presence of an acid catalyst such as hydrochloric acid or oxalic acid. As the phenol resin, a modified one may be used, and for example, it may be modified with an oil such as rosin oil, tall oil, cashew oil, linoleic acid, oleic acid, linoleic acid. In addition, about the phenol resin mentioned above, 1 type can be used individually and 2 or more types can also be mixed and used.

Further, the content of the phenol resin is preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and 10 parts by mass or less with respect to 100 parts by mass of the rubber component. It is preferably 7 parts by mass or less. By setting the content of the phenol resin to 2 parts by mass or more with respect to 100 parts by mass of the rubber component, the crack propagation resistance can be further improved, and by setting it to 10 parts by mass or less, deterioration of low loss property can be suppressed. it can.

(Methylene donor)
In the rubber composition suitable as the elastomer 3 used for the elastomer-metal cord composite 10 of the present invention, the above 50% modulus value (M50) is improved by including a methylene donor as a curing agent for the phenol resin. It is possible to improve the reinforcing property of the rubber composition while maintaining excellent low loss property.

The methylene donor is not particularly limited and can be appropriately selected depending on the required performance. For example, hexamethylenetetramine, hexamethoxymethylolmelamine, pentamethoxymethylolmelamine, hexamethoxymethylmelamine, pentamethoxymethylmelamine, hexaethoxymethylmelamine, hexakis- (methoxymethyl) melamine, N, N ′, N ″ -trimethyl-N , N ', N "-trimethylolmelamine, N, N', N" -trimethylolmelamine, N-methylolmelamine, N, N '-(methoxymethyl) melamine, N, N', N "-tributyl-N , N ′, N ″ -trimethylolmelamine, paraformaldehyde, etc. Among these methylene donors, from the group consisting of hexamethylenetetramine, hexamethoxymethylmelamine, hexamethoxymethylolmelamine and paraformaldehyde. Is-option, is preferably at least one. In addition, these methylene donors may be used alone, in combination can also be used.

Further, the ratio of the content of the phenol resin to the content of the methylene donor is preferably 0.6 or more and 7 or less from the viewpoint of achieving both low loss property and crack growth resistance at a higher level. More preferably, it is 5 or less. By setting the ratio of the content of the phenol resin to the content of the methylene donor to be 0.6 or more, M50 can be sufficiently improved and the crack propagation resistance can be sufficiently improved, while the above ratio is When it is 7 or less, the low loss property can be favorably maintained.

(Other ingredients)
The rubber composition suitable as the elastomer 3 used for the elastomer-metal cord composite 10 of the present invention contains the above-mentioned rubber component, carbon black, phenol resin, and methylene donor, and other components, and the effects of the present invention can be obtained. It can be included to the extent that it is not damaged. Examples of other components include fillers other than the above carbon black, antioxidants, crosslinking accelerators, crosslinking agents, crosslinking accelerators, silane coupling agents, stearic acid, ozone deterioration inhibitors, and surfactants. The additives commonly used in the rubber industry can be mentioned.

Examples of the above-mentioned filler include silica and other inorganic fillers, and among them, it is preferable to contain silica because excellent low loss property and crack growth resistance can be obtained.

Examples of silica include wet silica, colloidal silica, calcium silicate, aluminum silicate and the like. Among these, wet silica is preferably used, and precipitated silica is more preferably used. This is because these silicas have high dispersibility and can further improve the low loss property and abrasion resistance of the rubber composition. Precipitated silica is obtained by allowing the reaction solution to proceed at a relatively high temperature in a neutral to alkaline pH range at the early stage of production to grow silica primary particles, and then to control the acid to the acidic side. It refers to silica obtained as a result of aggregation.

The content of silica is not particularly limited, but from the viewpoint of realizing an excellent low loss property, it is preferably 1 part by mass or more, and 3 parts by mass or more with respect to 100 parts by mass of the rubber component. It is more preferable that the amount is 15 parts by mass or less, and it is more preferable that the amount is 10 parts by mass or less.

As the inorganic filler, for example, an inorganic compound represented by the following formula (I) can be used.
nM · xSiO _y · zH ₂ O ... (I)
(In the formula, M is a metal selected from the group consisting of aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, and hydrates thereof, and carbonates of these metals. And n, x, y, and z are an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10, respectively.)

As the inorganic compound of the above formula (I), alumina (Al ₂ O ₃ ) such as γ-alumina and α-alumina; alumina monohydrate (Al ₂ O ₃ · H ₂ O) such as boehmite and diaspore; gibbsite , Aluminum hydroxide [Al (OH) ₃ ] such as bayerite; aluminum carbonate [Al ₂ (CO ₃ ) ₃ ], magnesium hydroxide [Mg (OH) ₂ ], magnesium oxide (MgO), magnesium carbonate (MgCO ₃ ). ), talc _{_{(3MgO · 4SiO 2 · H 2}} O), attapulgite _{_{(5MgO · 8SiO 2 · 9H 2}} O), titanium white _(TiO 2), titanium black _{(TiO 2n-1),} calcium oxide (CaO), hydroxide calcium [Ca _(OH) 2], magnesium aluminum oxide _{_{(MgO · Al 2 O 3)}} , clay _(Al ₂ O 3 · 2S O _2), kaolin _{_{_{(Al 2 O 3 · 2SiO 2}}} · 2H 2 O), pyrophyllite _{_{_{(Al 2 O 3 · 4SiO 2}}} · H 2 O), bentonite _{_{_{(Al 2 O 3 · 4SiO 2}}} · 2H 2 O) , Magnesium silicate (Mg ₂ SiO ₄ , MgSiO ₃ etc.), aluminum aluminum silicate (Al ₂ O ₃ .CaO.2SiO ₂ etc.), magnesium calcium silicate (CaMgSiO ₄ ), calcium carbonate (CaCO ₃ ), zirconium oxide (ZrO ₂ ), zirconium hydroxide [ZrO (OH) ₂ · nH ₂ O], zirconium carbonate [Zr (CO ₃ ) ₂ ] and hydrogen, an alkali metal or an alkaline earth metal for correcting electric charges such as various zeolites. Examples thereof include crystalline aluminosilicates and the like.

As the antiaging agent, known ones can be used and are not particularly limited. For example, a phenol anti-aging agent, an imidazole anti-aging agent, an amine anti-aging agent, etc. can be mentioned. These antioxidants can be used alone or in combination of two or more.

As the cross-linking accelerator, known ones can be used and are not particularly limited. For example, thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide; N-cyclohexyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazylsulfenamide, etc. Sulfenamide-based vulcanization accelerator; guanidine-based vulcanization accelerator such as diphenylguanidine; tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetradodecylthiuram disulfide, tetraoctylthiuram disulfide, tetrabenzylthiuram disulfide, di Examples include thiuram-based vulcanization accelerators such as pentamethylene thiuram tetrasulfide; dithiocarbamate-based vulcanization accelerators such as zinc dimethyldithiocarbamate; zinc dialkyldithiophosphate. .

The cross-linking agent is also not particularly limited, and examples thereof include sulfur and bismaleimide compounds. Examples of the bismaleimide compound include N, N'-o-phenylene bismaleimide, N, N'-m-phenylene bismaleimide, N, N'-p-phenylene bismaleimide, N, N '-(4,4 Examples include'-diphenylmethane) bismaleimide, 2,2-bis- [4- (4-maleimidophenoxy) phenyl] propane, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane and the like. In the present invention, N, N'-m-phenylene bismaleimide and N, N '-(4,4'-diphenylmethane) bismaleimide can be preferably used.

Examples of the crosslinking accelerator include zinc white (ZnO) and fatty acids. The fatty acid may be saturated or unsaturated, linear or branched fatty acid, and the number of carbon atoms of the fatty acid is not particularly limited. For example, fatty acid having 1 to 30 carbon atoms, preferably 15 to 30 carbon atoms. , More specifically, cyclohexanoic acid (cyclohexanecarboxylic acid), naphthenic acid such as alkylcyclopentane having a side chain; hexanoic acid, octanoic acid, decanoic acid (including branched carboxylic acid such as neodecanoic acid), dodecanoic acid, Saturated fatty acids such as tetradecanoic acid, hexadecanoic acid and octadecanoic acid (stearic acid); unsaturated fatty acids such as methacrylic acid, oleic acid, linoleic acid and linolenic acid; resin acids such as rosin, tall oil acid and abietic acid . These may be used alone or in combination of two or more. In the present invention, zinc white and stearic acid can be preferably used.

When the rubber composition suitable as the elastomer 3 used for the elastomer-metal cord composite 10 of the present invention contains silica as the above-mentioned filler, it is preferable to further contain a silane coupling agent. This is because the effect of silica for reinforcement and low loss can be further improved. Known silane coupling agents can be used as appropriate. The preferred content of the silane coupling agent varies depending on the type of the silane coupling agent and the like, but is preferably 2% by mass or more, and particularly preferably 5% by mass or more, based on silica. It is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 18% by mass or less. When the content of the silane coupling agent is 2% by mass or more, the effect as the coupling agent can be sufficiently exerted, and when it is 25% by mass or less, gelation of the rubber component is prevented. it can.

The rubber composition suitable as the elastomer 3 used in the elastomer-metal cord composite 10 of the present invention is not particularly limited, and a rubber component as each component of the rubber composition, carbon black, a phenol resin, a methylene donor, and It can be prepared by blending other components and kneading. At this time, each of the above components may be kneaded at the same time, or any of the components may be kneaded in advance and then the remaining components may be kneaded. These conditions can be appropriately changed depending on the performance required of the rubber composition.

For example, from the viewpoint of achieving better low loss and crack growth resistance, it is preferable to mix and knead the rubber component and carbon black prior to kneading with the phenol resin. Phenolic resin has a strong interaction with carbon black, so if it is added at the same time, the reaction between the rubber component and carbon black may decrease. Therefore, by mixing and kneading the rubber component and carbon black prior to kneading with the phenol resin, the dispersibility and reinforcing properties of the carbon black are improved, and low loss and crack growth resistance can be further improved. Becomes

The elastomer-metal cord composite of the present invention can be manufactured by a known method. For example, a steel cord as a metal cord composed of a bundle of a plurality of metal filaments which are not twisted and twisted, can be produced by coating in parallel with a rubber at a predetermined interval, and a sample for evaluation is then prepared. It can be produced by vulcanizing under general conditions. Also, the metal filament can be molded by a conventional molding machine according to a conventional method.

Next, the tire of the present invention will be described.
FIG. 6 shows a schematic one-side sectional view of a tire according to a preferred embodiment of the present invention. The tire 100 of the present invention is formed by using the elastomer-metal cord composite 10 of the present invention, whereby the low loss property, the steering stability and the crack growth resistance can be improved. The illustrated tire 100 includes a tread portion 101 forming a ground contact portion, a pair of sidewall portions 102 continuously extending inward in the tire radial direction on both side portions of the tread portion 101, and an inner circumference of each sidewall portion 102. The pneumatic tire is provided with a bead portion 103 that is continuous on the side. Examples of the tire 100 of the present invention include tires for passenger cars and tires for trucks and buses.

In the illustrated tire 100, the tread portion 101, the sidewall portion 102, and the bead portion 103 are reinforced by a carcass 104 formed of one carcass layer extending in a toroidal shape from one bead portion 103 to the other bead portion 103. . Further, the tread portion 101 is reinforced by a belt 105 including at least two layers, which are two layers in the illustrated example, a first belt layer 105a and a second belt layer 105b, which are arranged outside the crown region of the carcass 104 in the tire radial direction. Has been done. Here, the carcass 104 may have a plurality of carcass layers, and an organic fiber cord extending in a direction substantially orthogonal to the tire circumferential direction, for example, an angle of 70 ° or more and 90 ° or less can be preferably used.

In the tire 100 of the present invention, the elastomer-metal cord composite 10 of the present invention can be used for the first belt layer 105a and the second belt layer 105b. By using the elastomer-metal cord composite 10 of the present invention, the thickness of the first belt layer 105a and the second belt layer 105b can be reduced, and the weight of the tire can be reduced. Further, by using the elastomer-metal cord composite 10 of the present invention for a cord for a belt, it is possible to simultaneously improve the durability, low loss, steering stability and crack growth resistance of the belt. The cord angle of the belt 105 can be 30 ° or less with respect to the tire circumferential direction.

The tire 100 of the present invention may be any tire as long as it uses the elastomer-metal cord composite 10 of the present invention, and other specific tire structures are not particularly limited. Further, the application location of the elastomer-metal cord composite 10 of the present invention is not limited to the belt 105. For example, it may be used as a belt reinforcing layer arranged on the outer side in the tire radial direction of the belt 105, or as other reinforcing members. As the gas with which the tire 100 is filled, in addition to normal air or air whose oxygen partial pressure is adjusted, an inert gas such as nitrogen, argon, or helium can be used.

Hereinafter, the present invention will be described in more detail with reference to examples.

(Preparation of rubber composition)
Rubber compositions A and B were prepared by compounding and kneading according to a conventional method according to the compounds shown in the following table. The kneading of each component was performed using a Banbury mixer with a capacity of 3.0 L. Regarding the rubber composition B, the rubber component and carbon black were kneaded prior to the kneading with the phenol resin. The 50% modulus value (M50) and the 200% modulus value (M200) of each rubber composition are measured according to JIS K 6251 (2010) after vulcanizing each rubber composition at 145 ° C. for 40 minutes to obtain a vulcanized rubber. ).

* 1) HAF grade carbon black, Asahi Carbon Co., Ltd. "Asahi # 70L", DBP absorption ^amount: 75cm 3 / 100g, nitrogen adsorption specific surface area: ^81m 2 / g
* 2) “Sumilite Resin PR-50235” manufactured by Sumitomo Bakelite Co., Ltd.
* 3) "CYREZ 964" made by ALLNEX
* 4) "Nipseal AQ" manufactured by Tosoh Silica Co., Ltd., nitrogen adsorption specific surface area = 210 m ² / g
* 5) "Nocrac NS-6", 2,2'-methylenebis (4-methyl-6-tert-butylphenol) manufactured by Ouchi Shinko Chemical Co., Ltd.
* 6) "Nocrac 6C" manufactured by Ouchi Shinko Chemical Co., Ltd., N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine * 7) Insoluble sulfur (trade name: Christex HS OT -20, manufactured by Flexis)
* 8) "NOXCELLER DZ" manufactured by Ouchi Shinko Chemical Co., Ltd., N, N-dicyclohexyl-2-benzothiazolylsulfenamide * 9) "MANOBOND C" manufactured by OMG, organic acid in cobalt salt of organic acid Salt with boric acid partially replaced, cobalt content: 22.0 mass%
* 10) "BMI-RB" manufactured by Daiwa Chemical Industry Co., Ltd.

Steel cords as metal cords according to the conditions shown in the following table are covered from both upper and lower sides with a sheet made of the rubber composition shown in the following table and having a thickness of about 0.5 mm, and the elastomer of each example and the conventional example. -Metal cord composite was made. In addition, when the molding amount is 0 mm and the molding pitch is ∞ mm, the steel filament is substantially straight.

For each elastomer-metal cord composite obtained, evaluate the elastomer coverage, steering stability, low loss, and crack growth resistance. The elastomer coverage is calculated by the following procedure. The results obtained are also shown in the table below.

<Elastomer coverage (%)>
The elastomer coverage is the steel that constitutes the steel cord by coating the steel cord with rubber, vulcanizing at 160 ° C. for 10 to 15 minutes, and then pulling out the steel cord from the obtained rubber-steel cord composite. The length of the side surface of the steel filament in the width direction of the metal cord, which is covered with the rubber that has penetrated into the gap between the filaments, is measured, and the average of the values calculated based on the following formula is calculated. The formula for calculating the elastomer coverage is as follows.
Elastomer coverage = (rubber coating length / sample length) x 100 (%)
The rubber coating length is the length of the region where the steel filament surface is completely covered with rubber when the pulled-out steel cord is observed from the direction orthogonal to the cord longitudinal direction. The higher the number, the higher the adhesive strength and the better the performance.

<Steering stability>
The in-plane rigidity is evaluated using the crossed belt layer sample prepared by using the obtained rubber-steel cord composite, and is used as an index of steering stability. Jigs are placed at the lower two points and the upper one point of the cross belt layer sample, and the load when the jig is pushed in from the upper one point is evaluated as the in-plane rigidity. The results are evaluated by using the conventional example 1 as a reference, inferior as x, equivalent as Δ, excellent as o, and very excellent as o.

<Low loss>
Each rubber composition A, B was vulcanized at 145 ° C. for 40 minutes to obtain a vulcanized rubber. The loss tangent (tan δ) of the obtained vulcanized rubber was measured using a spectrometer (manufactured by Kamijima Seisakusho Co., Ltd.) under the conditions of a temperature of 24 ° C., a strain of 1% and a frequency of 52 Hz. The evaluation is indicated by an index when the tan δ of the rubber composition A sample is 100, and the smaller the index value, the better the low heat buildup.

<Crack growth resistance>
Each rubber composition A, B was vulcanized at 145 ° C. for 40 minutes to obtain a vulcanized rubber. A sheet of 2 mm × 50 mm × 6 mm was prepared from the obtained vulcanized rubber, and a small hole was made in the center thereof to form an initial crack. Thereafter, this sheet was repeatedly stressed in the long side direction under the conditions of 2.0 MPa, frequency of 6 Hz, and ambient temperature of 80 ° C. Then, after the repeated stress was applied to each sample until the test piece was broken, the common logarithm of the repeated number was calculated. The measurement test until breakage was carried out four times for each sample to calculate the common logarithm, and the average thereof was taken as the average common logarithm. The evaluation is shown as an index when the average common logarithm of the rubber composition A is 100, and the larger the average common logarithm of the sample, the better the crack growth resistance.

* 11) Four bundles of steel filaments having a molding amount x1 mm and a molding pitch y1 mm and three steel filaments having a molding amount x2 mm and a molding pitch y2 mm are alternately arranged to form a bundle aligned in a row. Is the code structure.
* 12) Two-dimensional embedding: This means that the embedding direction of the embossed metal filament in the metal cord is the width direction of the metal cord, and the metal filament is imprinted in a zigzag shape.
* 13) A: Rubber composition A, B: Rubber composition B
* 14) This is the thickness of the rubber present on the metal cord in the belt layer of each example and the conventional example.
* 15) This is the thickness of the rubber existing between the metal cords in the belt layers of the examples and the conventional example, measured in the direction orthogonal to the longitudinal direction of the metal cord.

Further, the elastomer-metal cord composite of Example 1 was also excellent in separation resistance when the elastomer-metal cord composite of Conventional Example 1 was used as a reference.

As shown in the above table, the composition of the bundle of metal filaments is prescribed, and by using an elastomer that satisfies the prescribed physical properties, steering stability, crack growth resistance, low loss, etc. It is possible to obtain an elastomer-metal cord composite and a tire that are compatible with various tire performances.

1, 1a, 1b Metal filament 2 Metal cord 3 Elastomer 10 Elastomer-metal cord composite 100 Tire (pneumatic tire)
101 tread portion 102 sidewall portion 103 bead portion 104 carcass 105 belt 105a first belt layer 105b second belt layer

Claims

In an elastomer-metal cord composite in which a metal cord composed of a bundle in which a plurality of metal filaments are not twisted and aligned in a row is coated with an elastomer,
In the metal cord, there is at least one pair of adjacent metal filaments having different at least one of a molding amount and a molding pitch, and a 200% modulus with respect to a 50% modulus value (M50) of the elastomer. The ratio M200 / M50 of the value (M200) is 5.0 or less, the elastomer-metal cord composite.
The elastomer-metal cord composite according to claim 1, wherein a molding direction of the molded metal filament in the metal cord is a width direction of the metal cord.
The elastomer-metal cord composite according to claim 1 or 2, wherein an elastomer coverage of the adjacent metal filaments on a side surface in the width direction of the metal cord is 10% or more per unit length.
The elastomer-metal cord composite according to any one of claims 1 to 3, wherein at least one of the metal filaments in the metal cord is a substantially straight metal filament.
The elastomer-metal cord composite according to claim 4, wherein the straight metal filaments and the shaped metal filaments are alternately arranged.
The elastomer-metal cord composite according to claim 4 or 5, wherein the metal filaments arranged at both ends of the metal cord are the straight metal filaments.
7. The two-dimensional embossing is applied to the metal filament, the embossing amount of the metal filament is 0.03 mm or more and 0.30 mm or less, and the embossing pitch of the metal filament is 2 mm or more and 30 mm or less. The elastomer-metal cord composite according to any one of the above.
Wherein the elastomer comprises a rubber component, and carbon black DBP absorption is less than 50 cm 3/100 g or more 100 cm 3/100 g, and the phenol resin, of claims 1 to 7, comprising a rubber composition containing a methylene donor The elastomer-metal cord composite according to any one of claims.
A tire comprising the elastomer-metal cord composite according to any one of claims 1 to 8.