JPH11246835A - Adhesion promoter composition and adhesive rubber composition compounded with the same composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of imparting high adhesiveness with time and suitable for promotion of adhesiveness between steel cord to which brass plating is applied and coating rubber of steel cord by including a cobalt salt of an organic acid and an organic molybdenum compound. SOLUTION: This composition is obtained by including (A) a cobalt salt of an organic acid (e.g. Co neodecanoate) and (B) an organic molybdenum compound (e.g. Mo naphthenate or Mo neodecanoate), preferably in (1:100) to (100:1) molar ratio. An adhesive rubber composition obtained by compounding the above composition with at least one kind of rubber in natural rubber and synthetic rubber and sulfur is useful as a belt coating rubber of pneumatic tire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesion promoter composition and an adhesive rubber composition containing the same.
The present invention relates to a brass-plated steel cord, an adhesion promoter composition suitable for promoting adhesion between the steel cord and a coating rubber, and an adhesive rubber composition containing the same.

[0002]

2. Description of the Related Art In order to improve the performance of automobile tires and conveyor belts, steel cords are generally used as reinforcing materials. Such a steel cord is plated with brass in order to increase the adhesive strength with rubber and enhance its reinforcing effect. On the other hand, the rubber composition contains a cobalt salt of an organic acid as an adhesion promoter in order to increase the adhesion between the rubber and the steel cord. However, when a cobalt salt of an organic acid is used, the adhesiveness immediately after vulcanization is excellent, but the heat aging adhesiveness is inferior.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an adhesion promoter composition having a high adhesion which is stable over time and an adhesive rubber composition containing the same.

[0004]

Means for Solving the Problems To achieve the above object, the adhesion promoter composition of the present invention has the following constitution. (1) It is characterized by containing a cobalt salt of an organic acid and an organic molybdenum compound. (2) The molar ratio between the cobalt salt of the organic acid and the organic molybdenum compound is 1: 100 to 100: 1. Further, the adhesive rubber composition of the present invention has the following constitution. (3) a) a rubber component comprising at least one of natural rubber and synthetic rubber, b) any one of the above-mentioned adhesion promoter compositions, and c) sulfur. (4) With respect to 100 g of the rubber component, any one of the above-mentioned adhesion promoter compositions is 1.0 × 10 ^{−4 to} 2.0 × 10 ⁻ in terms of cobalt in the cobalt salt of the organic acid as the component. ^Two
It is characterized by being mixed in a molar amount of 1.0 × 10 ^{−6 to} 2.0 × 10 ⁻² mol in terms of molybdenum in the organic molybdenum compound.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
You. [1] The adhesion promoter composition of the present invention is as follows.
It is. a) As the organic acid constituting the cobalt salt of the organic acid of the present invention,
Are not particularly limited, and may be saturated, unsaturated,
It can be either a chain or a branched chain. Furthermore, naphthene rings and benzene
A bulky fatty acid having a ring or the like may be used. Specifically
Is neodecanoic acid, stearic acid, naphthenic acid,
Oil, oleic acid, linoleic acid, linolenic acid
Etc. can be exemplified. Some of these organic acids are boric acid.
Any boron containing compound can be substituted. b) The organic molybdenum compound of the present invention is an organic acid molybdenum
When the salt is an organic acid, the organic acid constituting the salt is as described above.
Similar, but when not an organic acid, its compound form is
There is no particular limitation, and molybdenum dithiophosphate (M
o-DTP) or molybdenum dithiocarbamate
Organic molybdenum sulfur compounds containing phosphorus and nitrogen
Is also good. Further, the adhesion promoter composition of the present invention comprises the above component
Besides, it is also possible to contain a hydrous inorganic salt,
In this case, the hydrated inorganic salt is NiSO_Four・ 7H_TwoO, C
oSO_Four・ 7H_TwoO, NaSO_Four・ 10H_TwoO, CaS
O_Four・ 2H_TwoO, CuSO_Four・ 5H_TwoO, Al_Two(SO
_Four)_Three・ 18H_TwoO, FeSO_Four・ 7H_TwoO, ZnSO
_Four・ 7H_TwoO, MgSO_Four・ 7H_TwoO, Na_TwoS ・ 9H
_TwoO, Na_ThreePO _Four・ 12H_TwoO, NaH_TwoPO_Four・ 2
H_TwoO, Na_TwoHPO_Four・ 12H_TwoO, Ni_Three(P
O_Four)_Two・ 8H_TwoO, Mg_Three(PO_Four)_Two・ 8H_TwoO,
Li_ThreePO_Four・ 5H_TwoO, Na_FourP_TwoO₇・ 10H
_TwoO, Ni_TwoP_TwoO₇・ 6H_TwoO, Mn_Four(P_TwoO₇)
_Three・ 14H_TwoO, CoCO_Three・ 6H_TwoO, NiCO_Three・
6H_TwoO, Na_TwoCO_Three・ 10H_TwoO, Nd_Two(C
O_Three)_Three・ 8H_TwoO, Na_TwoSO_Three・ 7H _TwoO, CaC
l_Two・ 6H_TwoO, NiCl_Two・ 6H_TwoO, Na_TwoB_FourO
₇・ 10H _TwoO, FeCl_Three・ 6H_TwoO, Na_TwoSiO
_Three・ 9H_TwoO and the like can be exemplified. Such hydrous inorganic salts
When mixed, the H content_TwoO is released,
Do not mix synthetic rubber with a relatively low water content or allow air to dry.
Even in winter, water can be secured and adhesive strength
Is considered to be able to avoid the decrease. Also, immediately after vulcanization
This is effective for improving the adhesive strength, that is, the initial adhesive strength.
Further, the organic acid constituting the adhesion promoter composition of the present invention
The ratio between the cobalt salt and the organic molybdenum compound is a molar ratio.
(Mo / Co) is preferably 0.01 to 100.
However, when the value is less than 0.01, the effect of molybdenum is sufficient.
If it is not obtained and exceeds 100, there is no change in the effect,
This is because the cost increases. Also, an adhesion promoter composition
When a hydrated inorganic salt is contained as a component of
H_TwoThe molar ratio of O to Co (H_TwoO / Co) is 0.1
１００100 is preferred, but less than 0.1
Insufficient effect can be obtained, and if it exceeds 100, the moisture content will increase
This is because the adhesiveness tends to decrease.

[2] The adhesive rubber composition of the present invention is as follows. As the rubber component, at least one of natural rubber and synthetic rubber is selected. As the synthetic rubber, styrene-butadiene rubber (SB) is used.
R), butadiene rubber, butyl rubber, halogenated butyl rubber, preferably brominated butyl rubber, butyl rubber having a paramethylstyrene group (specifically, a copolymer of isobutylene and p-halogenated methylstyrene, etc.), ethylene Examples thereof include propylene / diene rubber (EPDM) and isoprene rubber. From the viewpoint of adhesive properties and rubber breaking properties, it is preferable that at least one of natural rubber and synthetic isoprene rubber in the rubber component is 50% by weight or more. Further, regarding the adhesion promoter composition, as described above, the compounding ratio to the rubber component, the effect is not obtained when the amount of the adhesion promoter composition is less than a predetermined lower limit, a predetermined upper limit If the value exceeds the value, the cost is increased for the obtained effect. Further, the amount of sulfur is preferably 3 to 8 g with respect to 100 g of the rubber component. However, if the amount is less than 3 g, it is not possible to supply sufficient sulfur for generating Cu _x S that is a source of adhesive strength, When the adhesive strength is reduced and exceeds 8 g, Cu _x S is excessively generated, so that the cohesive failure of the enlarged Cu _x S occurs, the adhesive strength is reduced, and the heat aging resistance as rubber physical properties is also reduced. This is because there is a tendency.

Further, in the present invention, in addition to the above components, a compounding agent usually used in the rubber industry can be appropriately compounded in a usual compounding amount. Specifically, fillers such as carbon black and silica, softeners such as aroma oil, guanidines such as diphenylguanidine, thiazoles such as mercaptobenzothiazole, N, N'-dicyclohexyl-2-benzothiazolylsulfen Vulcanization accelerators such as sulfenamides such as amides, thiurams such as tetramethylthiuram disulfide, vulcanization accelerators such as zinc oxide, poly (2,2,4-trimethyl-1,2-dihydroquinoline) And aging inhibitors such as amines such as phenyl-α-naphthylamine. Of these, fillers such as carbon black and silica are known as reinforcing agents for increasing the tensile strength, breaking strength, modulus, hardness, etc. of vulcanized rubber, and improving abrasion resistance and tensile resistance. Therefore, zinc oxide is known as a vulcanization acceleration aid that forms a complex compound with a fatty acid and enhances the vulcanization acceleration effect. Further, the steel cord to be bonded to the adhesive rubber composition of the present invention, brass, zinc,
Alternatively, it is preferably plated with an alloy containing nickel or cobalt, and more preferably brass plating. When the content of Cu in the brass plating of the steel cord is 75% by weight or less, preferably 55 to 70% by weight, good and stable adhesion can be obtained. The twist structure of the cord is not particularly limited. Furthermore, the method for producing the adhesive composition according to the present invention and the adhesive rubber composition containing the same are according to a conventional method.

[0008]

The present invention will be described below based on examples and comparative examples. A rubber composition was prepared in accordance with the composition described in Notation 1, and a cord-reinforced rubber was prepared as described below, and tested by the following method. The results are shown in the same table. In addition, since the adhesiveness depends on the season of the rubber kneading day, the weather, and the like, the adhesiveness may be different if the rubber kneading date is different even if the composition is the same. In this embodiment,
In each case, the same rubber kneading date was used. (1) Tensile test For each rubber composition, after preparing a vulcanized sample under the conditions of 160 ° C for 20 minutes, JIS K6301-
In accordance with 1995, a tensile test was performed, and a tensile stress at 100% elongation (M ₁₀₀ ) and an elongation at break (E _B ) were measured. (2) Adhesion test Brass-plated (Cu: 63% by weight, Zn: 37% by weight) steel cords (1 × 5 structure, strand diameter 0.25mm) are arranged in parallel at 12.5mm intervals, and the steel cords are placed in parallel. Each side was coated with a sheet of each rubber composition from both sides, and this was vulcanized under the conditions of 160 ° C. × 20 minutes to obtain a sheet
A 2.5 mm sample was prepared, and AS
The steel cord was pulled out in accordance with TM-D-2229, and the pulling force at that time was measured. This was indicated as an index, with the value of Comparative Example 1 being 100 for each of the initial adhesiveness, heat aging adhesiveness, and wet heat aging adhesiveness. The larger the value, the better. Initial Adhesion Measured immediately after the vulcanization. Heat Aging Adhesion After the vulcanization, the sample was aged in air at 100 ° C. for 7 days and then measured at room temperature. Moisture and heat aging adhesion After the above vulcanization, 100 ° C in a constant temperature and humidity chamber of 70 ° C and 95% humidity.
After standing for a period of time, the measurement was performed at room temperature.

[0009]

[Table 1] * 1: N330 * 2: Ouchi Shinko Chemical Co., Ltd., trade name Nocrack 6C N- (1,3-dimethylbutyl) -N'-phenyl-p
-Phenylenediamine * 3: Ouchi Shinko Chemical Co., Ltd., trade name Noxeller DZ N, N'-dicyclohexyl-2-benzothiazolylsulfenamide * 4: Rhone Poulin, trade name Manobond C2
2.5

From the above, it can be seen that each of the examples has a high level of stable adhesiveness without deteriorating the physical properties of rubber.

[0011]

According to the present invention, it is possible to provide an adhesion promoter composition which does not cause adhesive deterioration and an adhesive rubber composition containing the same. Therefore, the present invention can be used particularly for promoting adhesion between a brass-plated steel cord and a coating rubber of the steel cord. Further, when the adhesive rubber composition of the present invention is used as a belt coating rubber for a pneumatic tire, it is possible to stably obtain an adhesive force with a reinforcing steel cord, thereby improving the durability of the belt. Can be.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Iida 3453 Miyatacho, Hitachi City, Ibaraki Prefecture Inside Nikko CIE Chemical Co., Ltd.

Claims (4)

[Claims] 1. An adhesion promoter composition comprising a cobalt salt of an organic acid and an organic molybdenum compound. 2. The adhesion promoter composition according to claim 1, wherein the molar ratio of the cobalt salt of the organic acid to the organic molybdenum compound is 1: 100 to 100: 1. 3. A rubber component comprising at least one of natural rubber and synthetic rubber; b) the adhesion promoter composition according to claim 1 or 2; and c) sulfur. Adhesive rubber composition. 4. The rubber composition according to claim 1, wherein the adhesion promoter composition according to claim 1 or 2 is 1.0 × 10 ⁻⁴ in terms of cobalt in a cobalt salt of an organic acid.
2.0 × 10 ^-2 mol and adhesive according to claim 3, characterized in that 1.0 is × 10 ^-6 ~2.0 × 10 ^-2 mol formulated in terms of molybdenum of the organic molybdenum compound Rubber composition.