JP6518147B2 - Metal cord-rubber complex - Google Patents

Description

  The present invention relates to a metal cord-rubber composite suitable for rubber articles such as tires, industrial belts and the like, which require high strength.

  Conventionally, rubber compositions such as steel cords and the like are used for reinforcing rubber to improve the strength and durability of rubber articles such as tires for automobiles and the like, industrial belts, rubber crawlers and the like that are required to have strength. A metal cord-rubber composite formed by coating a metal cord is used. Here, in order for such a metal cord-rubber composite to exhibit a high reinforcing effect, it is necessary to bond the metal cord and the rubber composition stably and strongly.

  For example, in a pneumatic tire that is a typical example of a rubber article, a steel cord made of rubber is formed by twisting a plurality of brass-plated steel wires on its belt or carcass, or consisting of a single wire of steel wire. The coated rubber composite is applied and mainly reinforced by steel cords. And, in order to utilize the steel cord as a reinforcing material for the tire, it is necessary to bond the steel cord securely to the coated rubber, and brass (Brass: Cu, Zn) plating is applied.

That is, a metal cord such as a brass-plated steel cord is coated with a rubber composition containing sulfur, and simultaneously with the vulcanization of the rubber composition, these are bonded [by forming a rubber metal bonding layer (CuxS) etc. So-called direct vulcanization bonding is widely used. Heretofore, various studies have been conducted to improve the adhesion between metal cords and rubber in this direct vulcanization bonding.
For example, in order to vulcanize and form a tire in a fixed time, it is required to secure sufficient adhesion by the bonding speed between the cord and the rubber and the complete bonding thereof. That is, since so-called initial adhesion is required, a cobalt-containing compound such as a Co salt or a nickel-containing compound such as a Ni salt is added to the rubber in a considerable proportion as an adhesion promoter, or sulfur is compounded at a high proportion Things are needed.

On the other hand, conventionally, in order to improve the elongation at break of the tire, the compounding amount of the filler such as sulfur and carbon black etc. to be blended in the coated rubber composition is reduced or the dispersibility of the filler is improved. There is.
Therefore, although it is better for the elongation at break to have a smaller amount of sulfur, as described above, since it is better for the amount of sulfur to be larger for bonding, there is a problem that these performances are contradictory.

On the other hand, various proposals have been made for adjusting the composition of the coated rubber composition, as well as for metal cords and the like, such as wires, which are bonding partners of rubber.
For example, a steel wire coated on the peripheral surface with brass plating having a transition metal concentration of 0.01% by mass or more, a phosphorus concentration of 25% by mass or less, and a zinc concentration of 15% by mass or less on the surface Steel cord-rubber formed by coating a coated rubber using a rubber composition obtained by blending 0.5 to 5 parts by mass of a boron-containing compound per 100 parts by mass of a rubber component Complexes (see, for example, Patent Document 1) are known.
Although this steel cord-rubber composite is excellent in initial adhesion between coated rubber and steel cord, heat-resistant adhesion, etc., the required performance required for tires in recent years is high and further initial adhesion, At present, a metal cord-rubber composite excellent in heat-resistant adhesion and durability is in great demand.

JP 2009-215673 A (claims, examples, etc.)

  In view of the above-mentioned conventional problems and the present situation, the applicant of the present invention intends to solve this problem, and achieves high compatibility between elongation at break and adhesion, which is the conventional trade-off, with further metal cord and rubber. An object of the present invention is to provide a metal cord-rubber composite excellent in initial adhesion, heat resistant adhesion, and durability.

  The inventors of the present invention have intensively studied the problems of the prior art and the like, and as a result, in a metal cord-rubber composite formed by coating a rubber composition on a metal cord, a configuration in which the surface state of the metal cord is a specific physical property And by making the adhesion layer used as the interface of a metal cord and a covering rubber into a specific physical property, it discovers that the metal cord-rubber complex of the above-mentioned purpose is obtained, and came to complete the present invention.

That is, the present invention resides in the following (1) to (3).
(1) A metal cord-rubber complex, wherein the N atom on the surface of the metal cord is 2 to 60 atomic%, and the ratio of (S atomic%) / (sulfur content in rubber compounding) in the adhesive layer Is 6 or more, The metal cord-rubber complex characterized by the above-mentioned.
(2) The metal cord is treated with an aqueous solution of a transition metal salt having a pH of 6 or less, and then 1,2,4-triazole, 1,2,3-triazole, 3-amino-1,2,4-triazole, 4-amino- Treating with one or more triazole compounds selected from 1,2,4-triazole, benzotriazole, tolyltriazole, 3-mercapto-1,2,4-triazole, and then adhering to rubber. (1) The manufacturing method of the metal cord-rubber complex as described.
(3) A tire comprising the metal cord-rubber composite according to the above (1).

  According to the present invention, a metal cord-rubber composite having high elongation at break and adhesion at the same time and excellent in initial adhesion between metal cord and rubber, heat-resistant adhesion and durability, and metal cord A tire provided with a rubber composite is provided.

The present invention will be specifically described below by exemplifying embodiments of the present invention.
The metal cord-rubber complex of the present invention is a metal cord-rubber complex, and the N atom on the surface of the metal cord is 2 to 60 atomic%, and (S atomic%) / (rubber composition) in the adhesive layer It is characterized in that the ratio of sulfur content) is 6 or more.

[Metal cord]
The metal cord used for the metal cord-rubber composite of the present invention is formed by twisting a plurality of metal wires (metal steel wires) or is formed of a single wire of metal wires.
Although the metal wire to be used is not particularly limited, for example, wire materials such as iron, steel (stainless steel), lead, aluminum, copper, brass, bronze, monel metal alloy, nickel, zinc and the like can be mentioned.
The metal wire preferably has a plating layer produced by a conventional method on its surface, and the plating layer is not particularly limited. For example, a zinc plating layer, a copper plating layer, a brass (brass) plating layer Among these, a brass (brass) plated layer is preferable from the viewpoint of initial adhesion to a rubber composition, heat resistant adhesion, and formation of a suitable rubber-metal adhesive layer.
The bulk brass plating composition constituting this brass (brass) plating layer is 40 to 80% by mass of Cu (copper) and 20 to Zn (zinc) in view of steel cord processability and adhesion to rubber. The content is preferably 60% by mass, and more preferably 55 to 70% by mass of Cu and 30 to 45% by mass of Zn.

A steel wire is mentioned as a metal wire and it demonstrates in more detail. The steel wire is a steel, that is, a linear metal whose main component is iron (more than 50% by mass of iron based on the total mass of the metal steel wire). The metal may include metals other than iron described above.
The wire diameter of the steel wire is preferably 0.1 mm to 5.5 mm, and more preferably 0.15 mm to 5.26 mm, from the viewpoint of workability and durability. Here, the wire diameter of the steel wire refers to the longest length between two points on the outer periphery in the cross-sectional shape perpendicular to the axis of the steel wire.
The cross-sectional shape perpendicular to the axis of the steel wire is not particularly limited, and may be elliptical, rectangular, triangular, polygonal or the like, but is generally circular. When using a steel cord which is a metal reinforcing cord obtained by twisting the steel wire to a carcass or a belt of a tire, the cross-sectional shape of the steel wire is circular and the wire diameter is 0.1 mm to 0.5 mm. When using it for the bead core of a tire, it is preferable to make the said cross-sectional shape circular similarly, and to make a wire diameter into 1 mm-1.5 mm. Further, the steel wire preferably has a brass (brass) plating layer on its surface, and the thickness of the plating layer is not particularly limited, and is generally, for example, 100 to 300 nm.

In the present invention, for example, a plurality of metal wires such as steel wires coated with brass on the circumferential surface are twisted together, for example, into a 1 × 3 structure, 1 × 5 structure, etc. Metal cord can be obtained.
The metal cord suitable for reinforcing a rubber article such as a steel cord is preferably at least one selected from the group consisting of a belt cord for a tire, a carcass cord and a bead cord.

In the present invention, the N (nitrogen) atoms on the surface of the metal cord are required to be 2 to 60 atomic% in terms of heat-resistant adhesion, treatability, and preferably in the surface of the metal cord. The N atom is desirably 2.1 to 55.0 atomic%, preferably 2.5 to 20%.
By setting the ratio of N atoms on the surface of the metal cord to 2 atomic% or more, the effects of the present invention can be sufficiently obtained, and if it is less than 2 atomic%, the wet heat deterioration adhesive performance is lowered, while 60 If the atomic percent is exceeded, the initial adhesion performance will be reduced.
In the present invention, the N (nitrogen) atom of the surface of the metal cord is adjusted to 2 to 60 atomic% by setting the N (nitrogen) atom of the surface of the metal cord to 2 to 60 atomic% (this range is below) The treatment is not particularly limited as long as it is a treatment or the like that can be referred to as “the above range”, but for example, in the production of metal cords such as steel cords used for metal cord-rubber composites, metal wire circumferential surfaces such as steel wires, Conduct brass plating with a concentration of transition metal excluding Zn and Cu of 0.01% by mass or more, a phosphorus concentration of 2.5% by mass or less, and a zinc concentration of 15% by mass or less on the surface, and then perform wire drawing Surface treatment of a metal wire such as the steel wire with a buffer having a pH of 5.0 to 7.2; 1,2,4-triazole, 1,2,3-triazole, 3-amino-1, Treatment with one or more triazole compounds selected from 2,4-triazole, 4-amino-1,2,4-triazole, benzotriazole, tolyltriazole, 3-mercapto-1,2,4-triazole, Furthermore, by adjusting the treatment time with the triazole compound, the surface of the metal wire such as steel wire or steel cord or metal cord is oxidized with time and generated, and the ZnO layer which inhibits adhesion with the coated rubber is dissolved. As a result, the Cu / Zn layer is exposed, and the N (nitrogen) atom on the surface of the metal cord can be adjusted to the above range (2 to 60 atomic%). Therefore, the copper sulfide (Cu _x S, x is 1 or 2) formed in the coating rubber by extracting Cu from the Cu / Zn layer at the time of vulcanization of the metal cord-rubber composite such as steel cord, etc. The initial adhesion between the steel cord and the coated rubber can be improved. Therefore, to improve initial adhesion without adding to the coated rubber a transition metal salt such as cobalt which causes the durability of the coated rubber to be reduced as described above in the coated rubber for coating the steel cord Is possible.
Also, from the viewpoint of improving the initial adhesion, the buffer solution of pH 5.0 to 7.2 preferably further contains a transition metal salt, particularly a cobalt salt.

  In the present invention, the "surface" is a surface region up to a depth of 5 (nm) radially inward of a metal wire such as a steel wire. The term "transition metal" refers to from scandium (Sc) to zinc in the fourth period of the periodic table, from yttrium (Y) to cadmium (Cd) in the fifth period, and from lutetium (Lu) in the sixth period. It refers to metallic elements up to mercury (Hg).

  Further, in the production of the metal cord for reinforcing the metal cord-rubber composite of the present invention, as the transition metal salt, a cobalt salt which works as an adhesion promoter between a coated rubber and a metal cord such as a plated steel cord is preferable. Further, as the cobalt salt, cobalt chloride, cobalt nitrate, cobalt sulfate, cobalt acetate, cobalt citrate, cobalt gluconate or cobalt acetylacetonate is preferable.

  The pH of the aqueous solution used for the washing is preferably 5.0 to 7.2, and more preferably 5.5 to 6.7, from the viewpoint of improving the initial adhesion performance. If the pH of the aqueous solution exceeds 7.2, the initial adhesion performance becomes insufficient, and if it is less than 5.0, the wet heat deterioration adhesion performance becomes insufficient, and the plating adversely affects the steel cord and the coated rubber. The adhesion of the As for the washing conditions, in the case of the aqueous solution containing the low pH transition metal salt, for example, a cobalt acetate-containing aqueous solution, the concentration of 10 g / L is preferable and the washing time is preferably 30 to 60 seconds, and the washing time depends on the concentration of the aqueous solution It can be decided appropriately.

The measurement of N atoms on the surface of the metal cord is carried out by, after obtaining the metal cord, performing washing treatment, drying and the like as necessary, and then measuring the surface of the metal cord before coating with the rubber composition. is there.
Further, in the present invention (including the examples described later), the measurement of N atoms on the surface of the above metal cord is carried out by the O of the surface of the metal cord measured by X-ray photoelectron spectroscopy (XPS). And Cu, Zn, N, and S, the percentage ratio of N atoms is measured.

[Rubber composition for metal cord coating]
The rubber composition used for the coated rubber of the metal cord-rubber composite of the present invention has a composition in which the ratio of (S atomic%) / (the sulfur content in the rubber composition) in the adhesive layer with the above metal cord is 6 or more If it is, it will not be specifically limited, For example, what contains sulfur, a Gobarth containing compound etc. with respect to 100 mass parts of rubber components is mentioned.
Although it does not specifically limit as a rubber component of a rubber composition used for this coating rubber, For example, natural rubber and / or synthetic polyisoprene rubber (IR) are preferable, and natural rubber is more preferable. Even in the case of combined use with other synthetic rubbers, the natural rubber content in the rubber component is preferably 60% by mass or more, more preferably 70% by mass or more, and 80% by mass or more More preferred is natural rubber alone.
Other synthetic rubbers include polybutadiene rubber (BR), styrene-butadiene copolymer (SBR), styrene-isoprene copolymer (SIR), acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber, ethylene -Propylene-diene terpolymer rubber, butyl rubber, halogenated butyl rubber, alkylated chlorosulfonated polyethylene rubber, isobutylene-isoprene copolymer rubber, diene rubber such as polychloroprene rubber, and the like. One of these rubber components may be used alone, or two or more thereof may be used in combination.

  It is preferable to mix | blend 7.0 mass parts or less of sulfur used as a vulcanizing agent to be used with respect to 100 mass parts of rubber components. In particular, it is in the range of 3.0 to 7.0 parts by mass, more preferably in the range of 4.0 to 6.0 parts by mass. If this sulfur is incorporated in an amount of 7.0 parts by mass or less, deterioration in the aging resistance of the coated rubber composition can be suitably prevented. Moreover, if 3.0 mass parts or more of sulfur is mix | blended, since initial stage adhesiveness improves, it is more preferable.

The cobalt-containing compound to be used is preferably compounded in an amount of 0.4 parts by mass or less (including 0 part by mass) as the amount of cobalt with respect to 100 parts by mass of the rubber component, and may be compounded in 0.01 to 0.4 parts by mass It is more preferable to mix | blend 0.02-0.3 mass part more preferable.
When the cobalt-containing compound is added in an amount of 0.4 parts by mass or less as the amount of cobalt, it is possible to preferably prevent the deterioration in the aging resistance of the coated rubber composition. In addition, it is more preferable to blend a cobalt-containing compound in an amount of 0.01 parts by mass or more, as the amount of cobalt, because the initial adhesiveness is improved.
Examples of Gobarth-containing compounds that can be used include cobalt (elementary substance), cobalt salts of organic acids, cobalt salts of inorganic acids, etc. For example, cobalt chloride, cobalt nitrate, cobalt sulfate, cobalt acetate, cobalt citrate, glucone Examples thereof include cobalt acid, cobalt naphthenate, cobalt neodecanoate, cobalt stearate, cobalt rosinate, cobalt versatate, cobalt tall oil, cobalt borate neodecanoate, cobalt acetylacetonate and the like.
In addition, it may be a complex salt in which a part of the organic acid is replaced with boric acid or the like. The organic acid cobalt salt containing boron is cobalt ortho borate having a cobalt content of 20 to 23% by mass. For commercial products, for example, Manobond C22.5 and Manobond 680C manufactured by Rhodia, CoMend A and CoMend B manufactured by Jhepherd, YYNBC-II etc. by Nippon Ink Chemical Industry Co., Ltd. can be illustrated.
These Gobald-containing compounds are conventionally blended in a coated rubber composition of a metal cord-rubber composite as an adhesion promoter, and in the present invention, the cobalt-containing compound used is based on 100 parts by mass of the rubber component. By adding 0.4 parts by mass or less as the amount of cobalt, it is possible to preferably prevent the deterioration in the aging resistance of the coated rubber composition. In addition, it is more preferable to blend a cobalt-containing compound in an amount of 0.01 parts by mass or more, as the amount of cobalt, because the initial adhesiveness is improved. In the present invention, the content of the Gobarth-containing compound is equivalent to the cobalt content.

The coated rubber composition of the metal cord-rubber complex according to the present invention may contain, in addition to the above-mentioned compounding agents, other compounding agents, for example, a vulcanizing activator such as zinc flower, organic acid (stearic acid etc.), Accelerators, inorganic fillers such as carbon black and silica, antioxidants, antiozonants, softeners and the like can be added.
In addition, as the vulcanization accelerator, for example, N, N'-dicyclohexyl-2-benzothiazolylsulfenamide, N-cyclohexyl-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzo Sulfenamide-based accelerators such as thiazolylsulfenamide and N-oxydiethylene-2-benzothiazolylsulfenamide are preferably used. Also, if desired, a thiazole type accelerator such as 2-mercaptobenzothiazole or di-2-benzothiazolyl disulfide, tetrabenzylthiuram disulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrakis (2- Ethylamyl) thiuram based accelerators such as thiuram disulfide and tetramethylthiuram monosulfide may be used.
The rubber composition used in the present invention can be produced by kneading, heating, and extruding each of these components in a conventional manner.

[Metal cord-rubber complex]
In the method for producing a metal cord-rubber composite according to the present invention, a metal cord in which the N (nitrogen) atom of the surface of the metal cord is adjusted to the above range is subjected to a cleaning treatment according to a conventional method, if necessary It can manufacture through the process which adheres the said metal cord and the said rubber composition for coating | covers.
By bonding the metal cord after passing through the surface treatment and the rubber composition having the above characteristics, for example, as described above, the metal cord is subjected to an aqueous solution treatment of a transition metal salt having a pH of 6 or less. The metal cord in which (nitrogen) atoms are adjusted to the above range and the rubber composition can be manufactured by vulcanization bonding under pressure heating. The vulcanization conditions are not particularly limited, but the pressure is preferably 2 MPa to 15 MPa, more preferably 2 MPa to 5 MPa, and the temperature is preferably 120 to 200 ° C., and more preferably 130 to 170 ° C. The vulcanization time is not particularly limited, but preferably 3 minutes to 60 hours.

In the metal cord-rubber composite of the present invention, the ratio of (S atomic%) / (sulfur content in rubber compounding) in the adhesive layer is 6 or more.
In the present invention, the above-mentioned “(S atom%) in the adhesive layer” is a metal which is obtained by removing the coated rubber from the metal cord-rubber complex and measuring it by X-ray photoelectron spectroscopy (XPS). The percentage ratio of S atoms among O, Cu, Zn, N and S on the surface of the cord is measured.
Moreover, the above-mentioned "sulfur content in rubber compounding" refers to the sulfur content with respect to 100 mass parts of rubber components in a covering rubber composition.
By setting the ratio of (S atomic%) / (the sulfur content in the rubber composition) in the adhesive layer to 6 or more, the initial adhesion to rubber and the heat-resistant adhesion can be improved by synergy with the metal cord of the above characteristics. An excellent metal cord-rubber composite is obtained.
In order to set the ratio of (S atomic%) / (the sulfur content in the rubber composition) in the adhesive layer to 6 or more, for example, N (nitrogen) atoms of the surface of the metal cord are in the above range (2 to 60) Adjusting by using a metal cord adjusted to atomic%) and using at least 7.0 parts by mass or less of sulfur as a coated rubber composition with respect to 100 parts by mass of a rubber component it can.

The metal cord-rubber composite of the present invention thus constituted makes it possible to achieve both elongation at break and adhesion at a high level, and to further improve initial adhesion between metal cord and rubber, heat resistance adhesion, and durability. Although there are some unclear points etc. about the mechanism etc. of whether it can be made an excellent metal cord-rubber complex, it is guessed as follows.
That is, in the metal cord-rubber composite according to the present invention, the metal cord-rubber composite, in which N atoms on the surface of the metal cord are 2 to 60 atomic%, and (S atomic%) / (in the adhesive layer) By increasing the adhesion of rubber and metal by setting the ratio of sulfur content in the rubber composition to 6 or more, and by using a metal cord in which the N atom of the surface of the metal cord is in a specific range The heat-resistant adhesive property is further improved, and a synergetic effect of the above-mentioned adhesive effect of rubber and metal and the heat-resistant adhesive property improving effect is produced, and an effect exceeding the total of the effects of individual technologies is exhibited. It is guessed that it is something.

  The metal cord-rubber composite which exerts the above-mentioned synergistic effect of the present invention is not particularly limited in application, but it is for automobile and other tires, industrial transmission belts such as dynamic transmission belts and conveyor belts, rubber crawlers and hoses It can be widely used for various rubber products and parts such as rubber supports for seismic isolation.

In particular, the metal cord-rubber composite of the present invention can be applied as a reinforcing material for tire members such as tire plies (carcass plies, belt plays) and bead members. The tire such as a pneumatic tire to be obtained is not particularly limited except that the metal cord-rubber composite of the present invention is used, and the configuration of a known tire can be adopted as it is.
The ply to which the metal cord-rubber composite is applied is suitably used as a carcass ply of a tire, a belt ply, and the rubber-metal composite is suitably used as a bead of a tire. Similarly, the metal cord-rubber complex is a rubber crawler, hose, rubber for seismic isolation mounted on an endless track drive used in industrial belts such as dynamic transmission belts, conveyor belts, bulldozers, etc. It is suitably used for a support body etc. Since these tires, industrial belts, rubber crawlers and the like are excellent in the adhesive strength between the rubber composition and the metal cord, they are difficult to peel off, and hence the durability is excellent despite the high load, and the long life and It will be

  EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[Examples 1 to 6 and Comparative Examples 1 to 3]
(Preparation of metal cord)
Brass plated (Cu: 63% by mass, Zn: 37% by mass) steel wire (0.2 μm thickness of plating layer, 0.3 mm wire diameter) is twisted to produce a steel cord of 1 × 5 structure, and then Then, wash the steel cord with 10 g / L cobalt acetate aqueous solution (pH 6.0) for 30 seconds, and then adjust the treatment time with an aqueous solution of 1,2,3-triazole concentration 10 g / L (0 to 60 seconds) After adjustment and cleaning within a range, the resultant was dried at 50 ° C. for 1 minute to obtain various metal cords in which the amount of N (the outermost surface N amount: atomic%) was varied.
The N content (upper surface N content: atomic%) of the plated surface of the steel wire in the metal cord after the cleaning treatment is measured under the following conditions using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Quantera) It measured by. The results are shown in Table 1 below.
The measurement conditions by X-ray photoelectron spectroscopy are as follows.
X-ray source: monochromated Al-Kα ray Measurement area: 50 μmΦ
Measured peaks: C1s, O1s, N1s, P2p, Cu2p2 / 3, Zn2p2 / 3
Data processing: Multipak (manufactured by ULVAC-PHI, Inc.)
Quantification: Quantification using the relative sensitivity factor method from the obtained peak area

  The metal cords (steel cords) obtained above are arranged in parallel at intervals of 12.5 mm, and each of the three rubber compositions A to which the rubber component types and the sulfur content shown in Table 2 below are varied from both the upper and lower directions It coated with C and was vulcanized at 160 ° C. for 7 minutes to bond the rubber composition and the steel cord, to prepare samples of Examples 1 to 6 and Comparative Examples 1 to 3 of predetermined thickness. For each sample, the ratio of (S atomic%) / (sulfur content in rubber compounding) in the adhesive layer, initial adhesion, and wet heat deterioration adhesion were evaluated by the following method. The results are shown in Table 1 below.

[Method of calculating the ratio of (S atomic%) / (Sulfur content in rubber compounding) in the adhesive layer]
“S (atom atom%) in the adhesive layer” is obtained by removing the coated rubber from the metal cord-rubber complex, and measuring the surface O of the metal cord measured by the above-mentioned X-ray photoelectron spectroscopy (XPS) method The percentage ratio of S atoms among Cu, Zn, N, and S was measured.
Moreover, "the sulfur content in rubber | gum compounding" refers to the sulfur content with respect to 100 mass parts of rubber components in a coating rubber composition.
The (S atomic%) in the adhesive layer was measured, and the ratio to be determined was calculated from the sulfur content shown in Table 2 below.

(Evaluation method of initial adhesion)
According to ASTM-D-2229, the initial adhesion of the metal cord-rubber composite (each sample) obtained in Examples 1 to 6 and Comparative Examples 1 to 3 is a steel cord from each sample immediately after vulcanization. The coating state of the rubber adhering to the steel cord was determined by visual observation to be 0 to 100%, and evaluated as follows.
A rating: 90% or more of rubber coating.
B evaluation: 80% or more and less than 90% of rubber coating.
C rating: 70% or more and less than 80% of rubber coating.
D rating: 60% or more and less than 70% of rubber coating.
E rating: less than 60% rubber coating.

(Evaluation method of wet heat deterioration adhesion)
The metal cord-rubber composite (each sample) obtained in the above Examples 1 to 6 and Comparative Examples 1 to 3 is deteriorated at 75 ° C. in an atmosphere of 95% relative humidity for 7 days, according to ASTM D 2229 The steel cord was pulled out from each sample, and the coverage of the rubber adhering to the steel cord was determined by visual observation at 0 to 100%, and evaluated by the following.
A rating: 90% or more of rubber coating.
B evaluation: 80% or more and less than 90% of rubber coating.
C rating: 70% or more and less than 80% of rubber coating.
D rating: 60% or more and less than 70% of rubber coating.
E rating: less than 60% rubber coating.

* 1 to * 4 in the above Table 2 are as follows.
* 1: JSR Corporation IR2200
* 2: Nouchi 6C, N-phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine * 3: Ouchi Shinko Chemical Co., Ltd., Noccellar DZ, N, N'-dicyclohexyl-2-benzothiazolylsulfenamide * 4: manufactured by OMG, Manobond C22.5, cobalt content 22.5 mass%

As apparent from the results of Tables 1 and 2 above, the metal cord-rubber composites of Examples 1 to 6 falling within the scope of the present invention have initial adhesiveness compared to Comparative Examples 1 to 3 outside the scope of the present invention. The wet heat deterioration adhesion was excellent, and the effect of the present invention could be confirmed.
Specifically, in Examples 1 to 6, the Cu / Zn ratio of the surface of the metal cord is constant, and the N atomic weight, and (S atomic%) in the adhesive layer / (sulfur in rubber compounding) It is a metal cord-rubber composite in which the ratio of the content) is varied within the scope of the present invention, and it has been confirmed that any of these metal cord-rubber composites can exhibit the effects of the present invention.
On the other hand, looking at Comparative Examples, Comparative Examples 1 to 3 have the N atomic weight of the surface of the metal cord, the ratio of (S atomic%) / (the sulfur content in the rubber compounding) in the adhesive layer of the present invention. A metal cord-rubber composite which is out of the range, and in these cases, it may be inferior in performance to any one or more of initial adhesion in cord / rubber adhesion and wet heat deterioration adhesion, and the effect of the present invention Could not be demonstrated.

  It is possible to provide a metal cord-rubber composite useful for various rubber products such as industrial belts such as tires, dynamic transmission belts, and conveyor belts.

Claims (3)

The rubber composition which is a metal cord-rubber composite, in which the N atom on the surface of the metal cord is 2 to 60 atomic% and which covers the metal cord, contains 60% by mass or more of natural rubber in the rubber component 3 to 6 parts by mass of sulfur are blended with respect to 100 parts by mass of the rubber component, and the ratio of (S atomic%) / (sulfur content in rubber composition ) in the adhesive layer is 6 or more Characterized metal cord-rubber composite.   After treating the metal cord with an aqueous solution of a transition metal salt having a pH of 6 or less, 1,2,4-triazole, 1,2,3-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2 A treatment according to one or more triazole compounds selected from 2,4-triazole, benzotriazole, tolyltriazole, 3-mercapto-1,2,4-triazole, and then adhesion to a rubber. Method of producing a metal cord-rubber composite according to   A tire comprising the metal cord-rubber composite according to claim 1.