JP2002356102A - Tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a tire and a retreaded tire, and a rubber composition for repairing a vulcanized rubber product, improving productivity without having adverse effect on other performance by using a specific rubber composition vulcanized at a low temperature in a short time compared to the usual case and obtaining high destruction resistant property. SOLUTION: The rubber composition used for a rubber member forming the shell interior of the tire and cushion rubber for the tread for retreading or for repairing a vulcanized rubber product is formed by compounding (1) at least one compound selected from a group comprising a thiuram compound expressed by a specific structural formula, and a dithiocarbamic acid salt compound expressed by a specific structural formula, (2) a compound of benzothiodisulfide or benzothiazole and (3) a compound of guanidine or aldehydeamine, to 100 pts.wt. of a rubber component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tire and a retreaded tire, and a rubber composition for repairing a vulcanized rubber product. Manufacturing method of retread tire applied to tire applied to tread, tread cushion material for retread,
And a rubber composition for repairing vulcanized rubber products.

[0002]

2. Description of the Related Art In the production of tires, short-time vulcanization is desired from the viewpoint of productivity. However, particularly in a tire having a large thickness, insufficient heat may be applied to the rubber member forming the inside of the tire shell during vulcanization, and insufficient vulcanization may occur. In particular, the rubber between the belts, the rubber between the belt and the carcass ply, and the cushion rubber between the tread rubber and the belt, cause tire failure due to insufficient rubber vulcanization near reinforcing materials such as steel cords and organic fiber cords. May cause Therefore, it is desired to use a rubber composition having a higher resistance to fracture even at low temperature and for a short time of vulcanization than the rubber member forming the surface of the tire shell, for the rubber member inside the tire shell. Also, in the manufacture of retreaded tires, usually, a pre-cure tread for retreading is pasted through a cushion rubber to a base tire that has removed a tread of a used tire and buffed to expose a retreaded surface, In this case, the vulcanization is performed by integral vulcanization. In this case, it is necessary to take into consideration not only the productivity but also the vulcanized base tire from being excessively vulcanized. A rubber having a high resistance to breakage even at a relatively low temperature and for a short time of vulcanization is required for a cushion rubber composition to be placed in a room.

Further, a rubber composition similar to that described above is also desired for repairing a bear of a new tire and partially repairing a damaged portion of a used tire. By the way, as a low-temperature, short-time vulcanizable accelerator, a thiuram-based super-accelerator represented by tetramethylthiuram disulfide (TT) has been known, but it generates carcinogenic nitrosamines. There was a problem of doing. For this reason, recently, for example, Japanese Patent Application Laid-Open No. 8-59898 discloses a rapid and low-temperature vulcanizable rubber composition containing no nitrosamine precursor, which contains tetrabenzylthiuram disulfide (TBZTD) and zinc dibenzyldithiocarbamate. A composition comprising a combination of vulcanization accelerators is disclosed. However, satisfactory results have not yet been obtained from both viewpoints of low-temperature rapid vulcanization and fracture resistance.

[0004]

SUMMARY OF THE INVENTION Under the above circumstances, the present invention provides a production method using a specific rubber composition which can be vulcanized at a lower temperature and in a shorter time than usual and has high fracture resistance. It is an object of the present invention to provide a tire, a method for manufacturing a retreaded tire, and a rubber composition for repairing a vulcanized rubber product, which have improved performance and do not adversely affect other performances.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that a plurality of specific combinations containing a specific tetrabenzylthiuram disulfide and / or zinc dibenzyldithiocarbamate are contained. It has been found that the above object can be achieved by using a vulcanization accelerator in combination. The present invention has been completed based on such findings.

That is, the present invention relates to a tire comprising a rubber member forming the surface layer of a tire shell, a rubber composite comprising a rubber forming the inside of the tire shell and a reinforcing material, and a rubber member forming the inside of the tire shell. As the rubber member forming the inside of the tire shell, (1) the general formula (I)

[0007]

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(Wherein R ^{1 to} R ⁴ each independently represent an alkyl group having 8 to 18 carbon atoms); and a thiuram compound represented by the general formula (II):

[0009]

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(Wherein R ⁵ and R ⁶ each independently represent an alkyl group having 8 to 18 carbon atoms) at least one compound selected from the group consisting of dithiocarbamate compounds represented by the formula: 1 to 4.0 parts by weight and (2) at least one compound selected from the group consisting of benzothiodisulfides, benzothiazoles, amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides 0.1 to 2.0 parts by weight and (3) 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of amines, guanidines, aldehyde amines, and aldehyde ammonias. An object of the present invention is to provide a tire characterized by using a rubber composition obtained by compounding the same.

The present invention also relates to a method for manufacturing a retreaded tire in which a cushion rubber member is arranged between a base tire and a retreaded tread rubber member and vulcanized, wherein the cushion rubber member is used in an amount of 100 parts by weight of a rubber component. On the other hand, (1) general formula (I)

[0012]

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A thiuram compound represented by the formula (wherein R ^{1 to} R ⁴ are as defined above);

[0014]

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Wherein at least one compound selected from the group consisting of dithiocarbamate compounds represented by the following formulas (wherein R ⁵ and R ⁶ are the same as defined above): 0.1 to 4.0 parts by weight,
(2) 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of benzothiodisulfides, benzothiazoles, amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides. When,
(3) amines, guanidines, aldehyde amines,
And at least one compound selected from the group consisting of aldehyde ammoniums and 0.1 to 2.0 parts by weight of the rubber composition. is there.

Further, the present invention relates to (1) the general formula (I) based on 100 parts by weight of the rubber component.

[0017]

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A thiuram compound represented by the formula (wherein R ^{1 to} R ⁴ are the same as defined above);

[0019]

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Wherein at least one compound selected from the group consisting of dithiocarbamate compounds represented by the following formulas (wherein R ⁵ and R ⁶ are the same as defined above): 0.1 to 4.0 parts by weight,
(2) 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of benzothiodisulfides, benzothiazoles, amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides. When,
(3) amines, guanidines, aldehyde amines,
And at least one compound selected from the group consisting of aldehyde ammonia and 0.1 to 2.0 parts by weight of the vulcanized rubber product. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The component (1) used in the rubber composition used in the present invention is a thiuram compound represented by the formula (I) or a dithiocarbamic acid represented by the general formula (II) It is a salt compound. Here, R ^{1 to} R
⁶ is an alkyl group having 8 to 18 carbon atoms, and particularly preferably an alkyl group having 8 to 12 carbon atoms. As a specific example,
A linear or branched group such as an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group is indicated. Preferred examples of the component (1) include tetra (2-ethylhexyl)
Thiuram disulfide (TOTD), tetra (dodecyl) thiuram disulfide, zinc dioctyldithiocarbamate and the like. The compounding amount of the component (1) is 0.1 to 4.0 parts by weight based on 100 parts by weight of the rubber component. If the amount is less than 0.1 part by weight, the effect of shortening the vulcanization is low, and the effect is 4.0.
Even if the amount exceeds parts by weight, no improvement in the effect is observed. From the viewpoint of these effects, the amount is preferably 0.4 to 2.0 parts by weight.

Next, the component (2) in the present invention is selected from the group consisting of benzothiodisulfides, benzothiazoles, amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides. At least one compound is used. Particularly, benzothiodisulfide, benzothiazoles, and amine salts or zinc salts of benzothiazoles are preferable. These (2)
Specific examples of the components include dibenzothiazothiazyl disulfide (MBTS), 2-mercaptobenzothiazole (M), and zinc salt of 2-mercaptobenzothiazole (M
Z), 2-mercaptobenzothiazolamine salt, N-
Cyclohexyl-2-benzothiazolesulfenamide (CBS), Nt-butyl-2-benzothiazolesulfenamide (BBS), N-oxyethylene-2
-Benzothiazolesulfenamide (OBS), N,
N-diisopropyl-2-benzothiazolesulfenamide (DPBS) and the like. The amount of the component (2) is 0.1 to 100 parts by weight of the rubber component.
2.0 parts by weight. If it is less than 0.1 part by weight, the effect of shortening the vulcanization is low, and if it exceeds 2.0 parts by weight, no improvement in the effect is observed. From the viewpoint of these effects, the amount is preferably 0.3 to 1.5 parts by weight.

Further, as the component (3) in the present invention, at least one compound selected from the group consisting of amines, guanidines, aldehyde amines, and aldehyde ammonias is used. These (3)
Specific examples of the components include diphenyl guandinine (DP
G), diortotolyl guanidine (DOTG), ortho tolyl biguanide (OTBG), n-butyraldehyde / aniline reaction product (BAA), hexamethylenetetramine (H), acetaldehyde / ammonia (AA)
And the like. The component (3) is used in an amount of 0.1 to 2.0 parts by weight, preferably 0.3 to 1.0 part by weight, per 100 parts by weight of the rubber component.

In the rubber composition to which the vulcanization accelerator comprising the components (1) to (3) is added, the rubber component is not particularly limited, and natural rubber or diene rubber is used. As the diene rubber, for example, polyisoprene synthetic rubber (I
R); cis-1,4-polybutadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (C
R), butyl rubber (IIR) and the like. These rubbers may be used in combination of two or more. Among them, rubber containing natural rubber, particularly rubber containing 70% by weight or more of natural rubber is preferable. In the present invention, sulfur is usually used as a vulcanizing agent, and its compounding amount is 10
0.1 to 5.0 parts by weight, preferably 1.0 part by weight, per 0 parts by weight.
~ 3.5 parts by weight. If the amount is less than 1.0 part by weight, the co-vulcanizability at the rubber / rubber interface may decrease, and if it is 3.5 parts by weight, the aging characteristics may decrease. In addition to the above components, the rubber composition may contain various additives such as a softener, carbon black, an inorganic filler, a tackifier, an antioxidant, and other vulcanization accelerators which are generally used in the rubber industry. A compounding agent can be appropriately compounded. The above rubber composition has a high vulcanization rate at a relatively low temperature and also has a high fracture resistance.

The rubber composition of the present invention is applied to a rubber member forming the inside of a tire shell. Here, the tire shell refers to a tire body that is not in a pneumatic state. In particular, when used for rubber members such as rubber between the belt layers, cushion rubber between the tread and the belt, and rubber between the belt and the ply, these are caused by insufficient vulcanization generated near the reinforcing material of these internal rubber members. Tire failure can be suppressed. Therefore, the rubber composition is suitably used for a tire internal rubber member, particularly from the viewpoint of tire productivity. Further, the rubber composition according to the present invention can be applied to a cushion rubber member located between a base tire and a tread rubber member for retreading in a method of manufacturing a retreaded tire. The tire vulcanization temperature in this case is preferably 100 to 130 ° C., which can suppress over-vulcanization of the vulcanized base tire. Furthermore, it can also be used as a rubber composition for repairing vulcanized rubber products such as tires. Usually, vulcanization is performed by attaching a rubber composition for repair to a repaired portion, but it is necessary to repair a rubber portion that is not repaired under conditions that do not cause over-vulcanization. In this case, the vulcanization temperature of the vulcanized rubber product is preferably from 120 to 150C.

[0026]

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, the vulcanization rate and the fracture resistance of the obtained rubber composition were measured by the following methods. 1. Vulcanization rate (t _0.9 ) The time (minutes) required to obtain 90% of the maximum value of the vulcanization torque curve measured at a temperature of 120 ° C. ± 1 ° C. using a CRS (manufactured by JSR Corporation). I asked. 2. Fracture resistance (rupture stress) According to JIS K 6251-1993, a tensile stress at break was measured at a test temperature of 30 ° C using a JIS # 3 type test piece.

Comparative Examples 1 to 3 and Examples 1 to 6 Rubber compositions having the compositions shown in Table 1 were prepared, and the vulcanization rate (t
_0.9 ) was measured. The rubber composition was heated at 120 ° C for 2 hours.
A test piece was prepared by vulcanization for 0 minutes, and the fracture resistance (rupture stress) was measured. The results are shown in Table 1.

[0028]

[Table 1]

Note: * 1 Carbon black: "Seast 300"[trademark;
Tokai Carbon Co., Ltd.] * 2 Antioxidant: "Nocrack 6C"[trademark; Ouchi Shinko Chemical Co., Ltd., N-phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine] * 3 Tackifier: "Cholecin" (pt-butylphenol / acetylene resin) * 4 DPG: Diphenylguanidine * 5 TDTD: Tetra (n-dodecyl) thiuram disulfide * 6 TBZTD: Tetrabenzylthiuram disulfide * 7 TOTD: Tetra (2-ethylhexyl) thiuram disulfide * 8 M: 2-mercaptobenzothiazole * 9 MZ: zinc salt of 2-mercaptobenzothiazole

From the above results, Example 1 of the present invention
It can be seen that the rubber compositions of Nos. 6 to 6 have a higher vulcanization rate and a higher resistance to breakage than those of Comparative Example 1. Further, since all of the thiuram compounds used as the component (1) used in the above Examples are liquid, Comparative Example 1
It is also advantageous in that the dispersibility during rubber kneading is higher than in the case of TBZTD powder. In addition, by applying the rubber composition of the example of the present invention to the rubber between the belt and the cushion rubber of the tire, a tire having improved productivity without impairing the tire performance could be obtained.

[0031]

As described above, according to the present invention, the above-mentioned specific rubber is used for the rubber inside the tire shell which causes a delay in vulcanization during the manufacture of the tire, and the cushion rubber for the base tire during the manufacture of the retreaded tire. By using the rubber composition of
It is possible to provide a method for producing a tire and a retreaded tire which has good productivity and does not adversely affect other performances. Further, it can be widely applied as a rubber composition for repairing general vulcanized rubber products.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) C08K 5/375 C08K 5/375 5/39 5/39 5/40 5/40 5/47 5/47 C08L 7/00 C08L 7/00 21/00 21/00 F term (reference) 4J002 AC011 AC051 AC061 AC071 AC081 AC091 BB181 EE019 EN009 EN049 EN069 ER029 EV048 EV147 EV167 EV328 EV348 FD010 FD016 FD090 FD140 FD157 FD158 FD159 GN01

Claims (18)

[Claims] 1. A tire comprising a rubber member forming a surface layer of a tire shell, a rubber composite comprising a rubber forming the inside of the tire shell and a reinforcing material, and a rubber member forming the inside of the tire shell. As a rubber member forming the inside, (1) general formula (I) with respect to 100 parts by weight of a rubber component (Wherein R ^{1 to} R ⁴ each independently represent a C 8 to C 18)
Represents an alkyl group. ), A thiurams compound represented by
And the general formula (II) (Wherein R ⁵ and R ⁶ each independently represent a carbon number of 8 to 1)
8 represents an alkyl group. 0.1) to 4.0 parts by weight of at least one compound selected from the group consisting of dithiocarbamate compounds represented by the following formulas) and (2) an amine salt of benzothiodisulfides, benzothiazoles, benzothiazoles or 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of zinc salts and benzothiazolylsulfenamides, and (3) amines, guanidines,
At least one compound selected from the group consisting of aldehyde amines and aldehyde ammonias;
A tire characterized by using a rubber composition in which the rubber composition is mixed with parts by weight. 2. The rubber member forming the inside of the tire shell is at least one rubber member selected from the group consisting of rubber between belt layers, cushion rubber between a tread and a belt, and rubber between a belt and a ply. Item 7. The tire according to item 1. 3. The tire according to claim 1, wherein the rubber component of the rubber member forming the inside of the tire shell contains natural rubber. 4. The tire according to claim 1, wherein the component (1) is at least one compound selected from tetra (2-ethylhexyl) thiuram disulfide and tetra (n-dodecyl) thiuram disulfide. 5. The method according to claim 1, wherein the component (2) is 2-mercaptobenzothiazole, benzothiazolylsulfenamide,
The tire according to claim 1, wherein the tire is at least one compound selected from a zinc salt of mercaptobenzothiazole and an amine salt of 2-mercaptobenzothiazole. 6. The vulcanization rate (t _0.9 ) when the rubber composition of the rubber member forming the inside of the tire shell is vulcanized at 120 ° C. for 20 minutes is 12 to 18 minutes and the breaking stress is 2
2. The tire according to claim 1, which has a pressure of 9.0 MPa or more. 7. A method for manufacturing a retreaded tire in which a cushion rubber member is provided between a base tire and a tread rubber member for retreading and vulcanized, wherein the cushion rubber member is based on 100 parts by weight of a rubber component. (1) General formula (I) (Wherein R ^{1 to} R ⁴ are the same as described above), and a compound represented by the general formula (II): Wherein R ⁵ and R ⁶ are the same as described above, and at least one compound selected from the group consisting of dithiocarbamate compounds represented by the following formula (1): 0.1 to 4.0 parts by weight, and (2) benzothiodisulfide (B) benzothiazole, 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides; Using at least one compound selected from the group consisting of aldehydes, guanidines, aldehyde amines, and aldehyde ammonias in an amount of 0.1 to 2.0 parts by weight. Tire manufacturing method. 8. The method for producing a retreaded tire according to claim 7, wherein the tire vulcanization temperature is 100 to 130 ° C. 9. The method for manufacturing a retreaded tire according to claim 7, wherein the rubber component of the cushion rubber member contains natural rubber. 10. The method according to claim 7, wherein the component (1) is at least one compound selected from tetra (2-ethylhexyl) thiuram disulfide and tetra (n-dodecyl) thiuram disulfide. 11. The method according to claim 1, wherein the component (2) is 2-mercaptobenzothiazole, benzothiazolylsulfenamide,
The method for producing a retread tire according to claim 7, wherein the compound is at least one compound selected from a zinc salt of 2-mercaptobenzothiazole and an amine salt of 2-mercaptobenzothiazole. 12. The rubber composition for a cushion rubber member,
Vulcanization rate at 120 ° C for 20 minutes (t _0.9 )
The tire according to claim 9, wherein the tire has a breaking stress of 12 to 18 minutes and a breaking stress of 29.0 MPa or more. 13. With respect to 100 parts by weight of the rubber component,
(1) General formula (I) (Wherein R ^{1 to} R ⁴ are the same as described above), and a compound represented by the general formula (II): Wherein R ⁵ and R ⁶ are the same as described above, and at least one compound selected from the group consisting of dithiocarbamate compounds represented by the following formula (1): 0.1 to 4.0 parts by weight, and (2) benzothiodisulfide (B) benzothiazole, 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of amine salts or zinc salts of benzothiazoles, and benzothiazolylsulfenamides; For repairing vulcanized rubber products, characterized by containing 0.1 to 2.0 parts by weight of at least one compound selected from the group consisting of aldehydes, guanidines, aldehyde amines, and aldehyde ammonias. Composition. 14. The rubber composition according to claim 13, wherein the rubber component contains a natural rubber. 15. The (1) compounded in the rubber composition
The component is at least one compound selected from tetra (2-ethylhexyl) thiuram disulfide and tetra (n-dodecyl) thiuram disulfide.
3. The rubber composition according to 3. 16. The (2) compounded in the rubber composition
The rubber composition according to claim 13, wherein the component is at least one compound selected from 2-mercaptobenzothiazole, benzothiazolylsulfenamide, zinc salt of 2-mercaptobenzothiazole and amine salt of 2-mercaptobenzothiazole. object. 17. The vulcanization temperature of a rubber product is 120 to 15
The rubber composition according to claim 13, which is at 0 ° C. 18. The rubber composition according to claim 1, wherein the rubber composition has a vulcanization rate (t _0.9 ) of 12 to 18 minutes when vulcanized at 120 ° C. for 20 minutes and a breaking stress of 29.0 MPa or more. Item 14. The rubber composition according to Item 13.