JP3246172B2 - Rubber composition and method for vulcanizing and bonding with steel cord using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition, and more particularly, to a rubber composition having excellent adhesion performance when vulcanized to a steel cord and exhibiting high hardness. The present invention also provides a tire manufactured from such a rubber composition, a method of vulcanizing and bonding to a steel cord using such a rubber composition, and improving the hardness and dynamic modulus of rubber by using such a rubber composition. It's also about how to make it work.

[0002]

2. Description of the Related Art Tires, belts, hoses, etc.
In rubber products that need to be reinforced with steel cords, adhesion between rubber and steel cords is often a problem. Therefore, conventionally, a method of plating the surface of a steel cord with brass (brass) or zinc, a method of treating the surface of a steel cord with various chemicals, and compounding an adhesive together with various other compounding agents in a rubber processing step. Methods are known. Among these, the method of compounding an adhesive in the rubber processing step is widely adopted because it can be firmly vulcanized and bonded.

[0003] This method is also called kneading-type bonding. In general, a methylene acceptor and a methylene donor which generates formaldehyde by heating are compounded with rubber in a processing stage, and the obtained unvulcanized rubber and steel cord are combined. At the time of vulcanization. And, as methylene acceptors, m-resins such as resorcinol and m-aminophenol
A method using a substituted phenol, a method using a condensate of an m-substituted phenol with an aldehyde such as formaldehyde or acetaldehyde, a condensate obtained by reacting another mono-substituted phenol with an aldehyde together with the m-substituted phenol And the like.

Among these, m-methylene receptor is m-
Methods using substituted phenols, especially resorcinol, improve the hardness of rubber, improve the elastic modulus during dynamic deformation,
It is possible to make rubber tough,
It has been widely used in the past because it has a small loss coefficient during dynamic deformation and is effective in improving heat resistance. However, resorcinol remarkably sublimates during rubber processing such as kneading, and is not preferable in terms of environmental hygiene. Furthermore, unvulcanized rubber containing resorcinol has a disadvantage that resorcinol blooms on the rubber surface, and thus causes a decrease in adhesiveness between unvulcanized rubbers.

As means for improving these disadvantages, US Pat. No. 2,746,898, Japanese Patent Publication No. 45-27463 (= US Pat. No. 3,596,696), and Japanese Patent Publication No. 47-7640 (= GB Patent No. 1,163,594) ) Proposed a condensate of resorcinol and formaldehyde. Although such a so-called resorcinol resin shows some improvement in dispersibility in rubber, since a large amount of unreacted resorcinol remains in the resin, the problem of evaporation of resorcinol and poor adhesion due to bloom of resorcinol still remain. Was left. Further, such a resorcinol resin is liable to deliquesce, and thus has a handling problem that it solidifies during storage of the resin. Further, the rubber containing such resorcinol resin has a hardness and a dynamic elastic modulus,
There was also a problem that it was significantly inferior to those containing resorcinol.

In order to improve the deliquescence and solidification of the resin, Japanese Patent Publication No. 52-26275 (= US Pat. No. 3,963,652)
No. 56-37902 (= U.S. Pat. No. 4,257,9
No. 26) proposed a ternary cocondensate composed of resorcinol, alkylphenol and formaldehyde, and a mixture composed of a condensate of resorcinol and formaldehyde and a condensate of alkylphenol and formaldehyde. These alkylphenol-containing resorcinol-based resins have the same or better effects as the adhesive properties and rubber properties obtained when using conventional resorcinol resins, and have the disadvantages of conventional resorcinol resins such as deliquescence and solidification. It improves the performance. However, even in these alkylphenol-containing resorcinol-based resins, unreacted resorcinol still remains to some extent,
Sublimation is a problem in environmental hygiene, and furthermore, rubber containing such an alkylphenol-containing resorcinol-based resin is not always sufficient in hardness, dynamic elastic modulus and loss coefficient. I was

Further, Japanese Patent Application Laid-Open No. 58-147444 discloses that
A rubber composition containing a compound capable of donating a methylene group upon heating together with 4,4-trimethyl-2 ', 4', 7-trihydroxyflavan is disclosed. The rubber composition described in this publication is not always satisfactory in vulcanization adhesiveness with a steel cord, and has not yet reached a satisfactory level in hardness, dynamic elastic modulus and loss coefficient.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have conducted various studies to solve the disadvantages of known resorcinol resins and resorcinol resins containing alkylphenols, and as a result, completed the present invention. Was.

Accordingly, one of the objects of the present invention is to provide a rubber composition from which a vulcanized rubber having a high hardness, a high dynamic modulus and a small loss coefficient can be obtained.

Another object of the present invention is to provide a compound which does not show deliquescence or solidification during storage and which does not show sublimation during rubber kneading and processing.
An object of the present invention is to provide a rubber composition which is provided with excellent vulcanization adhesion to a steel cord and hardly deteriorates in mechanical properties.

It is a further object of the present invention to provide a tire made from such a rubber composition.

Still another object of the present invention is to provide a method for vulcanizing and bonding to a steel cord using such a rubber composition.

Still another object of the present invention is to improve the hardness and the dynamic elastic modulus of rubber by blending a specific component with rubber.

[0014]

The present invention provides a rubber (A) 100 selected from natural rubber, styrene butadiene copolymer rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene copolymer rubber, chloroprene rubber, butyl rubber and halogenated butyl rubber. The present invention provides a rubber composition containing the following components (B) to (D) in parts by weight.

(B) Formula (I)

[0016]

Wherein R ¹ , R ² , R ³ , R ⁴ and R
⁵ is each independently hydrogen or an aliphatic group having 1 to 6 carbon atoms, and when R ¹ , R ² , R ⁴ and R ⁵ are all linear aliphatic groups, R ¹ and R ^{2 are May} be bonded, and R ⁴ and R ⁵ may be bonded to each other to form a ring; X
And Y are each independently hydrogen, a hydroxyl group or an aliphatic group having 1 to 8 carbon atoms), wherein 0.5 to 10 parts by weight of a flavan-based compound represented by 0.5 to 1 part by weight, and 0.5 to 6 parts by weight of (D) a methylene donor selected from a condensate of melamine, formaldehyde and methanol, and hexamethylenetetramine.

The present invention also provides a tire produced from the rubber composition, and further comprises compounding the components (B) to (D) with the rubber (A) and contacting the rubber (A) with a steel cord. A method of bonding rubber and steel cord by vulcanization, and a method of bonding the rubber (A) to the components (B) to
Provided is a method for improving hardness and dynamic elastic modulus of rubber by compounding (D) and vulcanizing.

The rubber (A) applied in the present invention comprises:
Natural rubber, styrene butadiene copolymer rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene copolymer rubber, chloroprene rubber, butyl rubber and halogenated butyl rubber, even if each is composed of a single rubber, or two or more It may be a blend of rubber.

The flavan compound of the component (B) is represented by the above formula (I). In the formula (I), R ¹ , R ² , R
³ , R ⁴ and R ⁵ are each independently hydrogen or an aliphatic group having 1 to 6 carbon atoms, and when R ¹ , R ² , R ⁴ and R ⁵ are all linear aliphatic groups, , R ¹ and R ²
And R ⁴ and R ⁵ may combine to form a ring, respectively. Aliphatic groups can usually be alkyl. When R ¹ and R ² combine to form one of a condensed ring, and when R ⁴ and R ⁵ combine to form one of a spiro ring, the thus formed rings each have, for example, 4 to 4 carbon atoms. There can be as many as 8 cycloalkane rings, most commonly a cyclohexane ring. X and Y each independently represent hydrogen, a hydroxyl group or a group having 1 to 8 carbon atoms.
Is an aliphatic group. The aliphatic group in this case can also usually be alkyl.

The flavan compounds of the formula (I) are disclosed in
It can be produced according to known methods described in JP-A-5-139375 and JP-A-61-27980. For example, resorcinol or a 4- and / or 5-substituted product thereof and a ketone, an α, β-unsaturated ketone, a β-hydroxyketone, an α, β-unsaturated aldehyde or a β-hydroxyaldehyde can be used in the presence of an acid catalyst. It can be obtained by performing a condensation reaction in an inert solvent below.

Specific examples of the flavan compounds represented by the formula (I) and suitable for use in the present invention include the following.

2 ', 4', 7-trihydroxyflavan, 2,4,4-trimethyl-2 ', 4', 7-trihydroxyflavan, 4-ethyl-2,3,4-trimethyl-2 ', 4 ', 7-trihydroxyflavan, 2,4
-Diethyl-4-methyl-2 ', 4', 7-trihydroxyflavan, 2,4,4-triethyl-3-methyl-
2 ', 4', 7-trihydroxyflavan, 2,4-dimethyl-3-isopropyl-4-isobutyl-2 ',
4 ', 7-trihydroxyflavan, 2,4-diisobutyl-4-methyl-2', 4 ', 7-trihydroxyflavan, 6-hydroxy-4a- (2,4-dihydroxyphenyl) -1,2,2 3,4,4a, 9a-Hexahydroxanthen-9-spiro-1'-cyclohexane [ie, in formula (I), X = Y = R ³ = H and R ¹
And R ² combine to form tetramethylene, and R ⁴ and R ⁵
Are bonded to form pentamethylene], 2,
4,4,5,6'-pentamethyl-2 ', 4', 7-trihydroxyflavan, 2,4,4-trimethyl-
2 ', 4', 5 ', 6,7-pentahydroxyflavan, 2,4,4-trimethyl-2', 4 ', 5,6',
7-pentahydroxyflavan, 2,4,4-trimethyl-5 ', 6-di-tert-butyl-2', 4 ', 7-trihydroxyflavan and the like.

Among the flavan compounds represented by the formula (I), those in which X and Y are each hydrogen are preferably used in terms of rubber performance. In particular, 2,4,4-trimethyl-2 ', 4', 7-trihydroxyflavan obtained by condensation of resorcinol and acetone is preferred from the viewpoint of raw materials and the like. All of the flavan compounds represented by the formula (I) solve the problem of transpiration in the rubber processing step as compared with resorcin.

The flavan compound of the component (B) is a rubber 1
It is added in the range of 0.5 to 10 parts by weight with respect to 00 parts by weight. Hereinafter, parts by weight of the compounding ingredients per 100 parts by weight of rubber are expressed in units of phr. The amount of flavan compounds is 0.5 p
If it is less than hr, the effect of improvement is insufficient, and if it is used in excess of 10 phr, further improvement effect due to an increase in the amount cannot be expected, which is uneconomical. Preferably, this compound is added in the range of 0.5 to 3 phr.

The organic cobalt compound as the component (C) can be, for example, an organic acid cobalt salt, an organic cobalt complex or the like. Specific examples of the cobalt salt of an organic acid include cobalt naphthenate, cobalt stearate, fatty acid cobalt such as cobalt propionate, cobalt benzoate, cobalt p-hydroxybenzoate, cobalt rosinate, and a fatty acid cobalt boron compound (for example, Brand names such as "Manobond C CP420" and "Manobond C 680C" manufactured by Manchem Corporation. Further, specific examples of the organic cobalt complex include cobalt acetylacetonate, acetoacetate anilide cobalt complex, and the like. Among these organic cobalt compounds, cobalt (II) carboxylate is preferably used. The organic cobalt compound is blended in the range of 0.05 to 1 phr in terms of the amount of cobalt. If the amount of cobalt is less than 0.05 phr, sufficient adhesion to the steel cord cannot be obtained, and if it is more than 1 phr, the heat resistance and flex crack resistance of the rubber are undesirably reduced.

The methylene donor of the component (D) is selected from a condensate of melamine, formaldehyde and methanol and hexamethylenetetramine, and can be used alone or in combination. Of these, condensates of melamine, formaldehyde and methanol are those usually used in the rubber industry, such as hexakis (methoxymethyl) melamine, pentakis (methoxymethyl) methylolmelamine, and tetrakis (methoxymethyl) dimethylolmelamine. There can be. Of these, hexakis (methoxymethyl)
Melamine alone or a mixture containing a large amount thereof is preferred. The methylene donor of component (D) is blended in the range of 0.5 to 6 phr, preferably in the range of about 1 to 4 phr.
If the amount of the methylene donor is less than 0.5 phr, it is not very effective in improving the adhesive performance and the hardness of the rubber, while if it is more than 6 phr, the elongation at break of the rubber is reduced, and the tensile strength after heat aging and This is not preferable because it lowers the retention of tensile stress.

By using the above components (B) to (D) in combination with the rubber (A), for example,
Excellent adhesion performance to steel cord, which cannot be obtained by the combination of the flavan-based compound and the methylene donor, can be achieved, and the hardness, the dynamic elastic modulus and the loss coefficient are greatly improved. In particular, with respect to the adhesive performance to a steel cord and the dynamic elastic modulus, it exhibits a performance exceeding that of a conventionally known rubber composition containing resorcinol.

Accordingly, the rubber composition containing the rubber (A) and the components (B) to (D) is particularly effective for vulcanization bonding with a steel cord. Examples of the steel cord to be bonded include a brass (brass) -plated steel cord, a galvanized steel cord, and the like. It is sufficient to reinforce with any of these, but of course, two or more types of steel cords may be used. It is especially effective for brass-plated steel cords.

The rubber composition of the present invention may further contain a reinforcing agent and / or a filler, if necessary. The reinforcing agents or fillers include various ones usually used in the rubber industry, for example, reinforcing agents such as carbon black, and inorganic fillers such as silica, clay and calcium carbonate. Above all, it is preferable to mix carbon black from the viewpoint of reinforcing properties, further rubber hardness, heat build-up, dynamic durability, etc., and particularly from the viewpoint of rubber hardness. Things such as SAF, ISAF, HAF, FEF, SRF, GPF,
MT or the like can be used. Reinforcing agents and / or fillers,
In particular, the compounding amount of carbon black is preferably in the range of 20 to 150 phr, and more preferably in the range of 40 to 80 phr. Further, it is also preferable to incorporate hydrated silica separately from or together with carbon black to improve adhesion. When hydrated silica is used, the compounding amount is preferably in the range of 5 to 40 phr.

In the present invention, various rubber chemicals usually used in the rubber industry, for example, antioxidants and antiaging agents such as antiozonants, vulcanizing agents, crosslinking agents,
One or more of vulcanization accelerators, vulcanization retarders, peptizers, tackifiers, processing aids, waxes, oils, stearic acid, etc., may be used in combination if necessary. Needless to say. These rubber chemicals can be used in amounts ranging from those commonly used in the rubber industry, depending on the intended use of the rubber composition.

Benzothiazole vulcanization accelerators,
For example, by blending 2-mercaptobenzothiazole, dibenzothiazyl disulfide, N-alkyl-substituted benzothiazylsulfenamide or N-alkyl-substituted benzothiazylsulfenimide and vulcanizing, an improvement in adhesion is expected. Therefore, such a benzothiazole vulcanization accelerator is preferably used. In the N-alkyl-substituted benzothiazylsulfenamide, the number of the alkyl substituted at the N-position may be one or two.
When two alkyls are bonded to the N-position, they may form a ring with the nitrogen atom, for example, a morpholine ring. The alkyl substituted at the N-position may be linear, branched or cyclic. Specific examples of N-alkyl-substituted benzothiazylsulfenamides include N-cyclohexyl-
2-benzothiazylsulfenamide, N-tert-butyl-2-benzothiazylsulfenamide, N-amyl-2-benzothiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide , N,
N-dicyclohexyl-2-benzothiazylsulfenamide and the like. Further, as the N-alkyl-substituted benzothiazylsulfenimide, N-tert-butyl-2
-Benzothiazylsulfenimide, N-cyclohexyl-2-benzothiazylsulfenimide and the like. Above all, from the viewpoint of improving hardness and adhesion,
N, N-Dicyclohexyl-2-benzothiazylsulfenamide is preferred. When a vulcanization accelerator, particularly a benzothiazole vulcanization accelerator is used, the compounding amount is 0.1 to 4 ph.
The range of r is preferred.

As an anti-aging agent, N-phenyl-
It is preferable to mix at least one selected from N'-1,3-dimethylbutyl-p-phenylenediamine and a 2,2,4-trimethyl-1,2-dihydroquinoline polymer. When compounding an anti-aging agent, usually 0.5 to
Used in the range of 3 phr.

The rubber composition of the present invention is usually vulcanized after blending a vulcanizing agent, preferably sulfur. Vulcanization is often performed in contact with steel cord. Sulfur as a vulcanizing agent can be insoluble sulfur or various soluble sulfur usually used in the rubber industry, and its compounding amount is usually in the range of about 1 to 10 phr. From the viewpoint of improving the adhesion to the steel cord, it is preferable to mix insoluble sulfur.
About 0 phr is preferred.

The rubber composition of the present invention thus compounded exhibits excellent effects when applied to various members of tires and other rubber products, particularly members reinforced with steel cords. For example, the rubber composition is applied to a tire, particularly a portion reinforced with a steel cord such as a carcass portion or a bead portion, and molded and vulcanized by a method commonly used in the tire industry to obtain a tire. Manufactured.

When vulcanizing under contact with steel cord, appropriate conditions differ depending on the type of base rubber and the type of various compounding agents. Further, even if vulcanization is performed in a state in which the vulcanization does not come into contact with the steel cord, a vulcanized rubber having excellent hardness and dynamic elastic modulus can be obtained. The vulcanization conditions themselves may be those generally used conventionally, and are not particularly limited in the present invention.

[0037]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In the following examples,% representing the amount added or the content
Parts and parts are by weight and parts by weight, respectively, unless otherwise noted.

The flavan compounds (B) used in the examples and the methylene acceptors used in the comparative examples are as follows, and are indicated by the respective symbols.

B1: 2,4,4-trimethyl-2 ',
4 ', 7-Trihydroxyflavan B2: 2,4-diethyl-4-methyl-2', 4 ',
7-trihydroxyflavan B3: 2,4,4-triethyl-3-methyl-2 ',
4 ', 7-Trihydroxyflavan B4: 2,4-diisobutyl-4-methyl-2',
4 ', 7-Trihydroxyflavan B5: 6-hydroxy-4a- (2,4-dihydroxyphenyl) -1,2,3,4,4a, 9a-hexahydroxanthene-9-spiro-1'-cyclohexane X : Resorcinol

Examples 1 to 5 <Formulation Formulation> 100 parts of natural rubber (RSS # 1) 45 parts of HAF carbon black (N330) 3 parts of stearic acid 3 parts of hydrous silica (Nipsil AQ manufactured by Nippon Silica Industry Co., Ltd.) 10 parts of zinc Flower 5 parts Antioxidant 2 parts (2,2,4-trimethyl-1,2-dihydroquinoline polymer) Flavan compound: Component (B) 2 parts Vulcanization accelerator 0.7 part (N, N-dicyclohexyl) 4-benzothiazylsulfenamide) Io 4 parts Cobalt naphthenate (cobalt content 11%): Component (C) 2 parts Methoxylated methylolmelamine resin: Component (D) 4 parts (Sumitomo Chemical Co., Ltd.) Sumikanol 507)

Using a 600 ml Labo Plastomill manufactured by Toyo Seiki Seisaku-Sho, Ltd. as a banbury mixer at a temperature of 150 ° C. in an oil bath, natural rubber,
Carbon black, stearic acid, hydrated silica, zinc white, an antioxidant and a flavan compound (B) were added and kneaded at a mixer rotation speed of 50 rpm for 15 minutes. The rubber temperature at this time was 145 to 160 ° C.

Next, the composition was transferred to an open mill,
At a temperature of 0 to 70 ° C, the vulcanization accelerator, sulfur, cobalt naphthenate and methoxylated methylolmelamine resin indicated in the above formulation were added and kneaded.

From a part of the kneaded sample, a test piece in which a brass-plated steel cord was embedded was prepared for an adhesion test, and was vulcanized at 150 ° C. for 30 minutes by a vulcanizing press. Also, the remaining sample is formed into a predetermined shape,
The specimen was vulcanized at 30 ° C. for 30 minutes to prepare test pieces for a dynamic viscoelasticity test, a hardness test and a tensile property test. The following tests were performed using each test piece, and the results are shown in Table 1.

Adhesion Test The adhesive strength when the rubber composition before vulcanization was brought into contact with a brass-plated steel cord and vulcanized was measured according to ASTM D 2138.
Was evaluated by the H test method described in the above section. The adhesion test result was 1
The average was obtained from two test pieces.

Dynamic Viscoelasticity Test A dynamic viscoelasticity test was performed using a viscoelasticity spectrometer F-III manufactured by Iwamoto Seisakusho Co., Ltd.
g, a dynamic load of 20 g, and a frequency of 10 Hz, the dynamic elastic modulus (E ′) and the loss coefficient (tan δ) at 60 ° C. were measured. The larger the value of the dynamic elastic modulus, the better the toughening effect, and the smaller the value of the loss coefficient, the more excellent the heat resistance and blowout resistance.

Hardness Test Hardness was measured using a spring type hardness tester (A type) using a right cylindrical test piece having a thickness of 12.7 mm in accordance with JIS K 6301.

[0047] in compliance with tensile properties test JIS K 6301, using dumbbell No.3 test pieces, tensile strength was measured M ₃₀₀ as elongation at break and tensile stress. The larger the tensile strength, elongation at break and tensile stress are, the more excellent the tensile properties are.

[0048]

Table 1 Results of Examples 1 to 5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example Component Adhesion Hardness at 60 ℃ Tensile properties No. (B) Dynamic viscoelasticity E 'tanδ Tensile strength Elongation at break M ₃₀₀ (N) (MPa) (MPa) (%) (MPa) ───────────────────────── ───────── 1 B1 280.8 42.9 0.061 83.7 23.73 440 17.36 2 B2 281.1 41.6 0.063 83.0 23.26 420 17.29 3 B3 279.8 42.9 0.062 84.1 22.55 420 17.18 4 B4 279.5 40.9 0.064 83.5 23.44 430 17.29 5 B5 280.4 41.5 0.062 83.2 23.69 430 17.27 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Comparative Example 1 The same experiment as in Example 1 was performed except that the components (B), (C) and (D) were omitted. The results are shown in Table 2.

Comparative Examples 2 to 7 The same experiment as in Example 1 or 5 was conducted except that one or two of the components (C) and (D) were omitted. The results are shown in Table 2.

Comparative Example 8 The same experiment as in Example 1 was performed except that resorcin (compound X) was used instead of the flavan compound of the component (B). The results are shown in Table 2.

[0052]

Table 2 Results of Comparative Examples 1 to 8 比較 Comparative Example Component Adhesion No. (B)-(D) Dynamic viscoelasticity E 'tanδ Tensile strength Elongation at break M ₃₀₀ (N) (MPa) (MPa) (%) (MPa) ───────────────────────── ────────── 1 No additive 205.5 9.2 0.109 68.7 26.68 500 13.34 2 B1 only 215.1 15.8 0.079 75.0 24.58 460 13.40 3 B1 + C 245.8 20.9 0.099 77.1 24.06 420 13.00 4 B1 + D 225.5 29.8 0.071 79.5 23.80 430 14.01 5 B5 only 209.4 10.9 0.084 73.3 24.14 440 13.11 6 B5 + C 238.8 17.9 0.104 75.5 23.00 420 13.85 7 B5 + D 220.0 25.5 0.082 76.2 23.92 430 13.26 8 X + C + D 249.9 30.1 0.068 80.3 21.89 410 16.44 ━━━成分 Component (C): cobalt naphthenate Component (D): methoxylated methylol melamine resin

[0053]

The rubber composition of the present invention contains a flavan-based compound that does not show transpiration during processing steps such as kneading and vulcanization, and has excellent vulcanization adhesion to steel cord. Show. The hardness of the vulcanized rubber is high,
Since the rubber is toughened and exhibits a high elastic modulus and a low loss coefficient in a dynamically deformed state, it has an excellent dynamic toughening effect. Therefore, by applying this rubber composition to a member reinforced with a steel cord and performing vulcanization bonding, a high-quality product can be obtained.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09J 121/00 (C08L 21/00 // (C08L 21/00 61:28) 61:28) C08K 5/15 (72) Invention Person Hideo Nagasaki 3-1-198, Kasuganaka, Konohana-ku, Osaka Sumitomo Chemical Co., Ltd. (56) References JP-A-58-147444 (JP, A) JP-A-58-160329 (JP, A) JP-A-5-104678 (JP, A) JP-A-54-52188 (JP, A) JP-A-1-168505 (JP, A) JP-A-57-137330 (JP, A) JP-A-61-279537 ( JP, A) JP-A-57-92034 (JP, A) JP-A-56-152852 (JP, A) JP-A-5-339423 (JP, A) JP-A-5-98081 (JP, A) Hei 1-152142 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 21/00 C08J 3/24 CEQ C08K 5/098 C08K 5 / 15 C08K 5/3477 C09J 121/00 C08L 21/00 C08L 61/28

Claims (16)

(57) [Claims] 1. A rubber selected from the group consisting of (A) natural rubber, styrene butadiene copolymer rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene copolymer rubber, chloroprene rubber, butyl rubber and halogenated butyl rubber.
(B) Formula (I) (Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen or an aliphatic group having 1 to 6 carbon atoms,
When R ¹ , R ² , R ⁴ and R ⁵ are all a chain aliphatic group, even if R ¹ and R ² are bonded and R ⁴ and R ⁵ are bonded to form a ring, Well; X and Y are
A flavan compound represented by hydrogen, a hydroxyl group or an aliphatic group having 1 to 8 carbon atoms).
Parts by weight, (C) 0.05 to 1 part by weight of an organic cobalt compound in terms of cobalt, and (D) 0.5 parts by weight of a methylene donor selected from a condensate of melamine, formaldehyde and methanol, and hexamethylenetetramine. 1 to 6 parts by weight of a rubber composition. 2. The rubber composition according to claim 1, comprising a flavan compound wherein X and Y in the formula (I) are each hydrogen. 3. The rubber composition according to claim 2, wherein the flavan compound is 2,4,4-trimethyl-2 ', 4', 7-trihydroxyflavan. 4. The rubber composition according to claim 1, wherein the organic cobalt compound as the component (C) is a cobalt carboxylate (II) salt. 5. The rubber composition according to claim 1, wherein the component (D) is a condensate containing hexakis (methoxymethyl) melamine. 6. A vulcanization accelerator selected from the group consisting of 2-mercaptobenzothiazole, dibenzothiazyl disulfide, N-alkyl-substituted benzothiazylsulfenamide and N-alkyl-substituted benzothiazylsulfenimide, in an amount of 0.1%. The rubber composition according to any one of claims 1 to 5, which contains the rubber composition in an amount of 4 to 4 parts by weight. 7. The rubber composition according to claim 6, wherein the vulcanization accelerator is N, N-dicyclohexylbenzothiazylsulfenamide. 8. The method according to claim 8, further comprising N-phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine and 2,2,2.
The rubber composition according to any one of claims 1 to 7, further comprising an antioxidant selected from 4-trimethyl-1,2-dihydroquinoline polymer. 9. The method according to claim 1, wherein the carbon black is 20 to 150.
The rubber composition according to any one of claims 1 to 8, which contains parts by weight. 10. The rubber composition according to claim 1, further comprising 5 to 40 parts by weight of hydrated silica. 11. The rubber composition according to claim 1, further comprising 1 to 10 parts by weight of sulfur. 12. The rubber composition according to claim 11, wherein the sulfur is insoluble sulfur and contains 4 to 10 parts by weight of the insoluble sulfur. 13. The rubber composition according to claim 1, which is vulcanized under contact with a steel cord. 14. A tire produced from the rubber composition according to claim 1. 15. A rubber selected from the group consisting of (A) natural rubber, styrene butadiene copolymer rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene copolymer rubber, chloroprene rubber, butyl rubber and halogenated butyl rubber; (Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen or an aliphatic group having 1 to 6 carbon atoms,
When R ¹ , R ² , R ⁴ and R ⁵ are all a chain aliphatic group, even if R ¹ and R ² are bonded and R ⁴ and R ⁵ are bonded to form a ring, Well; X and Y are
Each independently represents hydrogen, a hydroxyl group or an aliphatic group having 1 to 8 carbon atoms), (C) an organic cobalt compound, and (D) a condensate of melamine, formaldehyde and methanol, and hexamethylenetetramine. A method for bonding rubber and steel cord, comprising blending a selected methylene donor and vulcanizing it under contact with steel cord. 16. A rubber selected from the group consisting of (A) natural rubber, styrene butadiene copolymer rubber, butadiene rubber, isoprene rubber, acrylonitrile butadiene copolymer rubber, chloroprene rubber, butyl rubber and halogenated butyl rubber; (Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen or an aliphatic group having 1 to 6 carbon atoms,
When R ¹ , R ² , R ⁴ and R ⁵ are all a chain aliphatic group, even if R ¹ and R ² are bonded and R ⁴ and R ⁵ are bonded to form a ring, Well; X and Y are
Each independently represents hydrogen, a hydroxyl group or an aliphatic group having 1 to 8 carbon atoms), (C) an organic cobalt compound, and (D) a condensate of melamine, formaldehyde and methanol, and hexamethylenetetramine. A method for improving the hardness and dynamic elastic modulus of a rubber, which comprises mixing and vulcanizing a selected methylene donor.