WO2020080440A1 - Elastomer-metal cord composite body and tire using same - Google Patents

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 and separation resistance of belt layers; 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 if D is the wire diameter of the metal filaments, A is the cord width that is the maximum value of the distance from the surface of a metal filament at one end of the metal cord to the surface of a metal filament at the other end of the metal cord as measured in a direction that is perpendicular to the extending direction of the metal cord, and N is the number of the metal filaments that constitute the metal cord, D, A and N satisfy the relational expression 0.40 ≤ ((D/2)2 × π × N)/(D × A) ≤ 0.75.

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 that is continuous in the longitudinal direction is generated in the side surface portion of the adjacent metal filaments, and the tire is resistant to flooding when it is damaged. Corrosion developability deteriorates. In addition, when such a non-elastomer-covered region is present, the metal filaments are displaced from each other during rolling of the tire, and the in-plane rigidity (rigidity in the tire ground contact surface) is reduced, resulting in improved steering stability. I can't. Further, as the belt treat becomes thinner, the separation resistance of the belt layer deteriorates.

JP 2001-334810A

However, in Patent Document 1, although the BES resistance is examined, the steering stability and the separation resistance of the belt layer are not examined. Therefore, it has been required to realize a reinforcing material that can satisfy these required performances.

Therefore, the object of the present invention is to provide a metal cord comprising a bundle of a plurality of metal filaments that are aligned without being twisted, is covered with an elastomer, and various tire performances such as steering stability and separation resistance of a belt layer. An object of the present invention is to provide an elastomer-metal cord composite capable of improving the above-mentioned properties, and a tire using the same.

As a result of intensive studies by the present inventor, the above problem was solved by setting the bundle structure of the metal filaments as follows and by prescribing the ratio of the cross-sectional area of the metal filaments included in the cross section of the metal cord to a predetermined value. The inventors have found that it is possible to complete the present invention.

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, at least one pair of adjacent metal filaments different in at least one of the molding amount and the molding pitch is present, and
The wire diameter of the metal filament is D (mm), the distance from the surface of the metal filament constituting one end of the metal cord to the surface of the other metal filament measured in a direction orthogonal to the extending direction of the metal cord. Where the maximum cord width is A (mm) and the number of metal filaments forming the metal cord is N (the number), the following formula (1),
0.40 ≦ [(D / 2) ² × π × N] / (D × A) ≦ 0.75 (1)
(However, D, A> 0 and N is an integer) are satisfied.

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.

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, it is preferable that the metal filament has a mold amount of 0.03 mm or more and 0.30 mm or less and the metal filament has a mold pitch of 2 mm or more and 30 mm or less. .

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 composed of a bundle of a plurality of metal filaments drawn without being twisted is covered with an elastomer, and various tire performances such as steering stability and belt layer separation resistance are improved. It was possible to provide a possible elastomer-metal cord composite 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 in an elastomer-metal cord composite according to a preferred embodiment of the present invention. FIG. 3 is a schematic cross-sectional view in the width direction of a metal cord in an elastomer-metal cord composite according to a preferred embodiment of the present invention. FIG. 4 is an explanatory diagram relating to the definition of the ratio of the cross-sectional area of the metal filament included in the cross section of the metal cord in 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 the elastomer-metal cord composite according to a preferred embodiment of the present invention, and FIG. 3 is an elastomer-metal cord according to a preferred embodiment of the present invention. FIG. 4 is a schematic plan view of the metal cord in the composite, and FIG. 4 is a width-direction schematic cross-sectional view of the metal cord in the elastomer-metal cord composite according to a 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.

The present inventor has also found that good steering stability and separation resistance can be obtained in a well-balanced manner by prescribing the ratio of the cross-sectional areas of the metal filaments contained in the cross section of the metal cord. FIG. 5 shows an explanatory diagram relating to the definition of the ratio of the cross-sectional area of the metal filament contained in the cross section of the metal cord in the present invention. In this illustrated example, seven metal filaments 1 are not twisted but aligned to form a metal cord 2. Specifically, three metal filaments 1a and four metal filaments 1a are formed. The non-molded straight metal filaments 1b are arranged alternately on both sides of the metal filaments 1b (molding amount 0 mm, mold pitch ∞ mm).

In the present invention, as shown in the figure, the wire diameter of the metal filament 1 is D (mm), and the metal filament 1 at one end constituting the metal cord 2 is measured in a direction orthogonal to the extending direction of the metal cord 2. When the cord width, which is the maximum value of the distance from the surface to the surface of the metal filament 1 at the other end, is A (mm) and the number of the metal filaments 1 forming the metal cord 2 is N (the number), the following formula ( 1),
0.40 ≦ [(D / 2) ² × π × N] / (D × A) ≦ 0.75 (1)
(However, D, A> 0, and N is an integer). The above formula (1) defines the ratio of the cross-sectional area of the metal filament 1 occupying one of the metal cords 2 with the cross-sectional area of the dotted line portion in the figure as the cross-sectional area of the metal cord 2. That is, the cross-sectional area (cross-sectional area of the metal filament 1 + cross-sectional area of the elastomer 3) of the dotted line portion in the drawing is represented by the denominator (D × A) in the above formula (1) and is included in the dotted line portion of the drawing. The cross-sectional area of the metal filament 1 is represented by [(D / 2) ² × π × N] of the molecule in the above formula (1).

Therefore, in the elastomer-metal cord composite 10 of the present invention, the metal cord 2 including the predetermined pair of metal filaments 1 is used, and the cross-sectional area ratio of the metal filaments contained in the cross section of the metal cord is predetermined. When it is applied to a tire, it is possible to improve the weight, the steering stability, the corrosion resistance, the separation resistance of the belt layer, and the like in a well-balanced manner.

In the present invention, from the viewpoint of obtaining each performance in good balance, the following formula (2),
0.45 ≦ [(D / 2) ² × π × N] / (D × A) ≦ 0.75 (2)
It is preferable that the relationship expressed by
0.50 ≦ [(D / 2) ² × π × N] / (D × A) ≦ 0.75 (3)
It is more preferable to satisfy the relationship represented by

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. In particular, the arrangement of the metal filaments forming the bundle is preferably straight metal filaments whose both sides are 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 can be shaped in a two-dimensional shape in a zigzag shape or a wavy shape as illustrated. 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, the amount of the metal filament 1 to be imprinted 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. Particularly, 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 molded, the mold amount is preferably 0.03 mm or more and 0.30 mm or less, and more preferably 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, the mold 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 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. In this way, it is preferable to set the molding direction of the metal filaments 1 adjacent to each other to the width direction of the metal cord 2 because the weight is excellent.

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. 2, straight metal filaments 1b that are not shaped and metal filaments 1a that are shaped are arranged alternately.

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 D 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.

Furthermore, in the elastomer-metal cord composite 10 according to the present invention, the elastomer 3 for coating the metal cord 2 is not particularly limited, and rubber or the like conventionally used for coating the metal cord can be used. it can. Other than this, for example, 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 and 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), chlorosulfonated polyethylene rubber CSM), chlorinated polyethylene rubber (CM), halogenated rubber such as maleic acid modified chlorinated polyethylene rubber (M-CM), silicone rubber such as methyl vinyl silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber, polysulfide rubber Fluorine rubber such as sulfur-containing rubber, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicon rubber, fluorine-containing phosphazene rubber, styrene elastomer, olefin elastomer, ester A thermoplastic elastomer such as a system elastomer, a urethane elastomer, or a polyamide elastomer can be preferably used. These elastomers may be used alone or in combination of two or more. In addition to sulfur, a vulcanization accelerator, and carbon black, the elastomer may be appropriately blended with an antioxidant, zinc oxide, stearic acid and the like which are commonly used in rubber products such as tires and conveyor belts.

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, which can improve steering stability, corrosion resistance, and belt layer separation resistance. . 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 belt cord, it is possible to simultaneously improve steering stability, corrosion resistance, and belt layer separation resistance. 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 elastomer-metal cord composite)
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 having a thickness of about 0.5 mm made of the rubber composition shown below, and the elastomer-metal of each example and comparative example A code complex was created. In addition, when the molding amount is 0 mm and the molding pitch is ∞ mm, the steel filament is substantially straight. In addition, all the metal filaments in the metal cord were molded in the width direction of the metal cord, and the metal filaments were molded in a zigzag pattern.

Natural rubber 100 parts by mass Carbon black ^{* 1} 61 parts by mass Zinc white 5 parts by mass Antioxidant ^{* 2} 1 part by mass Vulcanization accelerator ^{* 3} 1 part by mass Sulfur ^{* 4} 5 parts by mass * 1) N326, DBP oil absorption 72 ml / 100 g, N ₂ SA 78 m ² / g
* 2) N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine (trade name: Nocrac 6C, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
* 3) N, N'-dicyclohexyl-2-benzothiazylsulfenamide (trade name: Nocceller DZ, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
* 4) Insoluble sulfur (Product name: Christex HS OT-20, manufactured by Flexis)

For each elastomer-metal cord composite obtained, evaluate the elastomer coverage and steering stability. 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 it 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 was covered with the rubber that had penetrated into the gap between the filaments, was measured, and the average of the values calculated based on the following formula was 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 was evaluated using the crossed belt layer sample produced by using the obtained rubber-steel cord composite, and used as an index of steering stability. A jig was placed at the lower two points and the upper one point of the intersecting belt layer sample, and the load when the jig was pushed in from the upper one point was evaluated as the in-plane rigidity. The results were evaluated with Comparative Example 1 as the reference x, when they were equivalent, they were evaluated as x, when they were excellent, they were evaluated as ◯, and when they were very excellent, they were evaluated as ⊚.

* 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.
* 14) This is the thickness of the rubber existing between the metal cords in the belt layers of each Example and Comparative 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 Comparative Example 1 was used as a reference.

As shown in the above table, the structure of the bundle of metal filaments, and the ratio of the cross-sectional area of the metal filaments contained in the cross section of the metal cord is defined as predetermined, so that the steering stability and the belt layer An elastomer-metal cord composite and a tire capable of improving various tire performances such as resistance to separation are obtained.

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 (8)

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, at least one pair of adjacent metal filaments different in at least one of the molding amount and the molding pitch is present, and
The wire diameter of the metal filament is D (mm), the distance from the surface of the metal filament constituting one end of the metal cord to the surface of the other metal filament measured in a direction orthogonal to the extending direction of the metal cord. Where the maximum cord width is A (mm) and the number of metal filaments forming the metal cord is N (the number), the following formula (1),
0.40 ≦ [(D / 2) ² × π × N] / (D × A) ≦ 0.75 (1)
An elastomer-metal cord composite characterized by satisfying a relationship represented by (where D and A> 0 and N is an integer). 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 elastomer-metal cord composite according to any one of claims 1 to 6, wherein the metal filament has a mold amount of 0.03 mm or more and 0.30 mm or less, and the metal filament has a mold pitch of 2 mm or more and 30 mm or less. body. A tire comprising the elastomer-metal cord composite according to any one of claims 1 to 7.

Images