JPH082972B2 - Adhesion method between polyester fiber and rubber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for adhering polyester fiber and rubber.

(Prior Art) Conventionally, in order to bond a polyester fiber and a rubber, the fiber is immersed in an aqueous dispersion containing a resorcinol-formaldehyde resin and a latex as a main component and used. As the latex, a butadiene-vinylpyridine-styrene copolymer latex or a blend latex of the latex and a styrene-butadiene copolymer latex or a natural rubber latex is generally used.

Polyester fiber is widely used as a rubber-reinforcing fiber in automobile tires, belts, hoses, etc., and is widely used. ing.
That is, when a vulcanization accelerator such as thiuram-based, sulfenamide-based, or guanidine-based vulcanization accelerator, an amine-based antiaging agent, or a natural rubber is mixed in the rubber of the molded product, for example, a long-term rubber used for manufacturing an automobile tire can be used. This is because the polyester fiber is deteriorated during the vulcanization process over time or during high-speed running of the automobile tire, and the performance as the reinforcing fiber is significantly deteriorated.

In order to improve this drawback, preferred vulcanization accelerators,
Improvement by rubber compounding method by selecting anti-aging agent, etc.
Although improvements have been made to the polyester fiber itself by reducing the amount of terminal carboxyl groups contained in the polyester fiber, this method limits the compounding of the rubber and the adhesive force between the vulcanized rubber and the fiber (hereinafter heat resistant adhesion) Power)
However, the heat deterioration of the fiber itself is improved but the heat resistant adhesive strength is not improved by the method.

(Problems to be Solved by the Invention) As a method for adhering fibers and rubbers having improved heat-resistant adhesive strength, the present inventors have found that vinylpyridines having different vinylpyridine contents in copolymers in respective treatment liquids. We proposed a method of treating polyester fibers with two kinds of treatment liquids containing a conjugated diene copolymer latex and a resorcinol-formaldehyde resin (Japanese Patent Application No. 61-278112). In this method, the heat-resistant adhesive strength is remarkably improved as compared with the conventional method in which the fiber is treated once with a treatment liquid containing a vinyl pyridine-based polymer latex, but as in the conventional method, an increase in the hardness of the fiber is avoided. No improvement is desired.

The present inventors have conducted extensive studies to solve this problem, and as a result, after treating the polyester fiber at a specific temperature in advance, treating the fiber by the above-mentioned two-step treatment method The inventors have found that the increase in hardness is prevented and the amount of the treatment liquid deposited is reduced, and the present invention has been completed.

(Means for Solving Problems) Thus, according to the present invention, when vulcanizing and adhering the polyester fiber and the rubber, the polyester fiber is 90 ° C.
Heat treatment is performed at the above temperature, and then (1) a resorcinol-formaldehyde resin and a vinylpyridine-conjugated diene copolymer latex (a) in which the vinylpyridine content in the copolymer is V1 (% by weight). And (2) the content of vinylpyridine in the resin and the copolymer is V2 (wt%), and V1-V2>
Achieved by using a method for adhering polyester fiber and rubber, characterized in that polyester fiber treated with a treatment liquid consisting of 10% by weight of vinylpyridine-conjugated diene rubber latex (b) is used. To be done.

As described above, the features of the present invention are as follows. First, the polyester fiber is treated with a treatment liquid containing a copolymer latex (hereinafter sometimes simply referred to as latex) (a), and then a latex of the copolymer rubber (b) is treated. It is to heat-treat the polyester fiber in advance when it is treated with the treatment liquid containing it. The desired heat-resistant adhesive strength can also be obtained by carrying out a two-step treatment with a treatment liquid containing latex (a) and a treatment liquid containing latex (b) on a normal polyester cord for tire cord without performing heat treatment in advance. However, it has the drawbacks that the treatment cord becomes hard and the fatigue resistance and the like decrease, and the treatment cost increases because the amount of adhesive adhered increases.

Such drawbacks are eliminated by heating polyester fibers in advance during the treatment with the above composition. The conditions for heat-treating the polyester fiber in advance are
A temperature of 90 ° C or higher is required. As a result, at a low temperature, an increase in the hardness of the fiber when treated with the treatment liquid is not prevented. More preferably, it is 140 ° C or higher. There is no particular upper limit to the treatment temperature, but if it exceeds 250 ° C., properties such as cord strength are impaired, which is not desirable. In addition, this heat treatment also reduces the amount of the treatment liquid deposited in the treatment with the next treatment liquid, and thus the economic merit becomes large.

The latexes (a) and (b) used in the present invention are obtained by emulsion polymerization of the following monomers. Examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene and halogen. One or more aliphatic conjugated diene-based monomers such as substituted butadiene are used. 2 for vinyl pyridine
-Vinyl pyridine is preferred, but 3-vinyl pyridine,
One or more of 4-vinylpyridine, 2-methyl-5-vinylpyridine, 5-ethyl-2-vinylpyridine and the like can be substituted.

The content of the conjugated diene-based monomer and vinyl pyridine constituting the latex (a) copolymer is 30 to 80% by weight of the conjugated diene-based monomer and 20% by weight of vinyl pyridine from the viewpoint of heat-resistant adhesive strength.
To 70% by weight, and more preferably 40 to 75% by weight and 25 to 60% by weight, respectively. Also,
If necessary, a monomer copolymerizable with the above two types of monomers may be used.
It can be contained in an amount of 40% by weight or less. The content of the monomer constituting the latex (b) copolymer rubber is preferably 40 to 95% by weight of the conjugated diene monomer and 5 to 60% by weight of vinylpyridine in terms of adhesive strength, and more preferably Are in the range of 50 to 90% by weight and 10 to 50% by weight, respectively. Further, a monomer copolymerizable with the above-mentioned two kinds of monomers can be contained in an amount of 30% by weight or less, if necessary.

Examples of the monomer copolymerizable with the conjugated diene monomer and vinyl pyridine include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, Aromatic vinyl compounds such as 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene, monochlorostyrene, dichlorostyrene, monofluorostyrene and hydroxymethylstyrene; acrylic acid, methacrylic acid Unsaturated acids such as crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, butenetricarboxylic acid; unsaturated dicarboxylic acids such as itaconic acid monomethyl ester, fumaric acid monobutyl ester, maleic acid monobutyl ester Monoalkyl ester of sulfoethyl acrylate Na Salt, sulfopropyl methacrylate sodium salt, acrylamidopropanesulfonic acid or its alkali salt; methyl acrylate, ethyl acrylate,
Examples thereof include unsaturated monocarboxylic acid esters such as methyl methacrylate and aliphatic vinyl compounds such as ethylene, propylene, acrylonitrile, and vinyl chloride, and one or more of these can be used.

The method for producing the latex of the present invention is not particularly limited, and all the monomers to be used may be put in a polymerization vessel all at once to be produced by one-step polymerization, or after the polymerization of a part of the monomers, the remaining It may be produced by a two-stage polymerization method in which the above monomer is added and the polymerization is continued.

Latex (a) and latex (b) are mixed with resorcinol-formaldehyde resin to form a polyester fiber treatment liquid, but the heat-resistant adhesive strength after vulcanizing and bonding the treated fiber and rubber is improved. It is necessary that latex (a) and (b) satisfy the following requirements.

That is, the content of vinyl pyridine in the copolymer constituting latex (a) and (b) [the content of latex (a) in the copolymer is V1% by weight, that of latex (b) is V2% by weight). It is necessary that the content of latex (a) is larger than that of (1), and it is a requirement that the relationship of V1-V2> 10% by weight is satisfied. If the difference in vinylpyridine content between both latexes is less than 10% by weight, the improvement in heat-resistant adhesive strength is small.

As the resorcinol-formaldehyde resin used in the present invention, the conventionally used resins (for example, those disclosed in JP-A-55-142635) can be used and are not particularly limited. Further, it may be used in combination with a compound such as a 2,6-bis (2,4-dihydroxyphenylmethyl) -4-chlorophenol composition which has been conventionally used for increasing the adhesive strength.

The treatment liquid used for treating the polyester fiber of the present invention is usually 10 to 180 parts by weight of the resorcinol-formaldehyde resin (dry) with respect to 100 parts by weight of the solid content of the latex (a) and (b) of the present invention. Weight) A mixture is used.

Further, a part of the latex of the present invention in the treatment liquid of the present invention is used as one of styrene-butadiene copolymer rubber latex and its modified latex, acrylonitrile-butadiene copolymer rubber latex and its modified latex, natural rubber latex and the like. It can be replaced by one kind or two or more kinds.

There is no particular limitation on the method of treating the polyester fiber with this treatment liquid, and the same treatment method as the treatment with the known quercinol-formaldehyde-polymer latex composition can be used.

The polyester fiber to which the method of the present invention is applied is not particularly limited as long as it is a linear polymer polyester.
Examples thereof include polyester fibers disclosed in JP-A-57-40184. The fibers are usually used in the form of threads, cords, continuous filaments, cloth, etc., but may be in other forms.

(Effect of the Invention) The method for adhering the polyester fiber and the rubber of the present invention provides the same initial adhesive force as in the case of using the conventional processing liquid, and the fiber is harder than that in the case of using the conventional processing liquid. It can be used for producing tires, belts, hoses and the like using polyester fiber because it is prevented from forming and the extremely high heat-resistant adhesive strength and heat resistance and strength of the fiber are improved.

(Example) Hereinafter, the present invention will be described more specifically with reference to Examples. The parts and% in the examples and comparative examples are based on dry weight unless otherwise specified.

Example 1 In an autoclave equipped with a stirrer, together with 150 parts of water, 0.1 part of tetrasodium salt of ethylenediaminetetraacetic acid, 5 parts of sodium lauryl sulfate, 0.5 part of sodium bicarbonate, 0.5 part of t-dodecyl mercaptan and 0.3 part of potassium sulphate, the results are shown in Table 1. A total of 100 parts of the monomer was charged and reacted at 60 ° C. while rotating and mixing. When the polymerization addition rate reached 95%, the reaction was stopped by cooling to remove unreacted monomers and to remove latex a-1, a-2, b.
-1, b-2 were obtained.

16.6 parts of resorcinol, 14.6 parts of formalin aqueous solution (37% concentration), and 1.3 parts of sodium hydroxide were dissolved in 333.5 parts of water and reacted at 25 ° C. for 2 hours with stirring. This is referred to as liquid (a).

Next, 100 parts of latex a-1 was added to the liquid (a), and the mixture was reacted at 25 ° C. for 20 hours while stirring. Next, 35 parts of Vulcabond E (Vulcabond E manufactured by Vulnax) was added.
This aqueous solution was adjusted to a solid content concentration of 20%. Similarly, the processing solutions were prepared using the latexes a-2, b-1 and b-2. These treatment liquids are A-1 liquid, A-2 liquid, B
Use solution -1 and solution B-2.

Next, the polyester tire cord (1500d / 2) was heat-treated at 200 ° C. for 1 minute with a test single cord dipping machine. Subsequently, this treatment code was immersed in the liquid A-1. After the immersion treatment, heat treatment was performed at 240 ° C. for 1 minute. Then, the immersion treatment was performed in the same manner using the liquid A-2. This processing code is called processing code A.

In the same manner, the cord was first immersed in the liquid B-1, heat-treated in the same manner as above, and then immersed in the liquid B-2. This processing code is called processing code B.

Next, the polyester tire cord (1500d / 2) was immersed in the test single cord dipping machine using the liquid A-1 without heat treatment in advance. After immersion treatment 24
Heat treatment was performed at 0 ° C. for 1 minute. Then, in the same manner, A-
Immersion treatment was performed using the two liquids. This processing code is called processing code C.

A commercially available vinylpyridine polymer latex (Nipol 2518 FS manufactured by Nippon Zeon Co., Ltd.) was used as a latex to prepare a treatment liquid having the same composition as the liquid A-1. Treated with the treatment liquid in the same manner as above using the heat-treated polyester tire cord and the non-heat-treated cord, to obtain treated tire cords D and E, respectively.

Table 2 Rubber compounding formula Natural rubber 100 parts Zinc white 5 Stearic acid 2 Sulfur 2.5 FEF carbon black 45 Process oil 5 N-Oxydiethylene-2-benzothiazylsulfenamide 1 2,2,4-Trimethyl-1,2 -Dihydroquinoline polymer 0.2 As shown in Table 3, by heat-treating the polyester tire cord prior to the treatment with the treatment liquid, the hardness of the cord can be suppressed to a significantly low level as compared to the case where the cord is not heat-treated (treatment cords A, B, Comparison of D and processing codes C and E).

Further, even if the treatment is performed twice, the improved heat-resistant adhesive force cannot be obtained when the latex which does not satisfy the requirements of the present invention is used (comparison between treatment codes B and A). further,
When the first treatment liquid is treated after the heat treatment, the adhesion amount of the treatment liquid is about 30% smaller than that when the heat treatment is not performed.
(Comparison of Treatment Codes A, B, D and Treatment Codes C, E) Example 2 Latex i under the same conditions as in Example 1 except that the monomers shown in Table 4 were used as the monomers used in the polymerization. -1, j
-1, i-2, j-2 were produced. Using these latexes, in the same manner as in Example 1, treating liquids I-1 liquid, I-2 liquid, J liquid
-1 liquid and J-2 liquid were prepared and heat-treated under the conditions shown in Table 4, and then the polyester cord was treated in the same manner as in Example 1 using these. The heat treatment temperature of the polyester cord was performed under the conditions shown in Table 4. Then, an adhesion test was conducted in the same manner as in Example 1. The results are shown in Table 4.

From Table 4, when the heat treatment conditions of the cord are out of the range of the present invention, the hardness of the treated cord becomes significantly high (treated cord D).
However, when the heat treatment condition of the cord is within the range of the present invention, the hardness of the treated cord can be suppressed to be low (treated cords E to J).
You can see that. Also, the difference in the vinylpyridine content of the copolymer in the latex used in the first and second baths (V1-V2)
However, it is also understood that the initial adhesive strength and the heat resistant adhesive strength are at low levels outside the scope of the present invention.

Claims (1)

[Claims] 1. When vulcanizing and adhering polyester fiber and rubber, the polyester fiber is heat-treated at a temperature of 90 ° C. or higher, and then (1) containing resorcinol-formaldehyde resin and vinylpyridine in the copolymer. Quantity
V1 (wt%) is treated with a treatment solution comprising vinyl pyridine-conjugated diene copolymer latex (ii), and then (2) the vinyl pyridine content in the resin and the copolymer is V2 (wt). %) And V1-V2> 10 (wt%), a polyester fiber treated with a treatment liquid comprising a vinylpyridine-conjugated diene copolymer latex (b). How to bond fibers and rubber.