JPH0721066B2 - 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) Fibers have been conventionally used by immersing the fibers in an aqueous dispersion containing a resorcinol-formaldehyde resin and a latex as main components in order to bond the polyester fibers and the rubber. As latex, butadiene-vinyl pyridine-
A styrene copolymer latex or a styrene-butadiene copolymer latex or a natural rubber latex is generally used.

Polyester fiber is widely used as a fiber for rubber reinforcement in automobile tires, belts, hoses, etc. because of its low elongation, but the fiber is significantly deteriorated depending on the conditions of use, so its use is restricted. There is. That is, when a rubber of a molded product contains a vulcanization accelerator such as thiuram-based, sulfenamide-based, or guanidine-based, an amine-based anti-aging agent, or natural rubber, for example, a long-term tire during automobile tire manufacturing is used. This is because the polyester fiber is deteriorated during a vulcanization process over time or during high-speed running of an automobile tire, and is remarkably reduced as a reinforcing fiber.

In order to ameliorate this drawback, a preferable vulcanization accelerator, an improvement by a rubber compounding method by selecting an antiaging agent,
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) 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 result of intensive studies conducted by the present inventors to develop a method for adhering fibers and rubbers having improved heat-resistant adhesive strength, as a result, polyester fibers were (1) firstly resorcinol-formaldehyde. Treated with a composition comprising a resin and a conjugated diene-based copolymer rubber latex having a specific gel amount and swelling degree,
(2) Next, it was found that the heat-resistant adhesive strength to the rubber is remarkably improved by treating the composition with the resin and a vinylpyridine-conjugated diene-based copolymer rubber latex and then vulcanizing and adhering the rubber. The present invention has been completed.

An object of the present invention is to provide a method for adhering a polyester fiber to a rubber when the polyester fiber is used as a reinforcing agent for a rubber product such as a tire, a belt and a rubber hose.

(Means for Solving Problems) An object of the present invention is to provide a polyester fiber by (1) first, when vulcanizing and adhering the polyester fiber and the rubber.
Treated with a composition comprising a resorcinol-formaldehyde resin and a conjugated diene-based copolymer rubber latex having a gel content of the copolymer rubber of 80% or more and a gel swelling degree of 20 times or less, (2) Then, it is achieved by using a method for adhering polyester fiber and rubber, which is characterized by treating with a composition comprising the resin and a vinylpyridine-conjugated diene copolymer rubber latex.

The features of the present invention are as described above, in which polyester fiber is first treated with a composition containing a conjugated diene copolymer rubber latex, and then vinyl pyridine-
It is to treat with a composition containing a conjugated diene-based copolymer rubber latex.

The conjugated diene-based copolymer rubber latex used in the present invention is obtained by emulsion copolymerizing a conjugated diene monomer and a monomer copolymerizable therewith.

Examples of the conjugated diene monomer include 1,3-butadiene,
2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-
One or more aliphatic conjugated diene-based monomers such as butadiene and halogen-substituted butadiene are used.
Usually, the conjugated diene monomer is used in the range of 50 to 99.9% by weight in the total monomer mixture.

Examples of the monomer copolymerizable with the conjugated diene monomer include styrene, α-methylstyrene, 2-methylstyrene,
3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t
-Aromatic vinyl compounds such as butyl styrene, 5-t-butyl-2-methyl styrene, monochlorostyrene, dichlorostyrene, monofluorostyrene, hydroxymethyl styrene, vinyl pyridine, methyl acrylate, ethyl acrylate, methyl methacrylate, etc. described below. Esters of unsaturated monocarboxylic acids and ethylene,
Propylene, acrylonitrile, vinyl chloride, etc. are exemplified, and one or more of these can be copolymerized. These monomers are usually 0 to 0 in the total monomer mixture.
Used in the range of 50% by weight.

Further, as the monomer other than the above, a crosslinkable monomer can be used for the purpose of adjusting the gel amount and the gel swelling degree. Crosslinkable monomers include methylenebisacrylamide, methylenebismethacrylamide, butanediol diacrylate, butanediol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate. , Allyl acrylate, allyl methacrylate, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate,
Examples thereof include triallyl cyanurate, triallyl isocyanurate and divinylbenzene. The amount of the crosslinkable monomer used is usually 0 to 20% by weight based on the total amount of the monomers. If the amount used is too small, the heat-resistant adhesive strength will be insufficient, and if it is too large, the polyester fiber will be hard. Desirably 0.1
~ 10% by weight.

In order to improve the heat-resistant adhesive strength, the conjugated diene copolymer rubber latex obtained by copolymerizing the above monomers has a gel content of the copolymer rubber of 80% or more, preferably 90% or more. And the degree of gel swelling is 20 times or less, preferably 12 times or less.

The gel content and gel swelling degree specified in the present invention are measured by the following methods.

Copolymer rubber latex is coagulated with ethanol, washed with water,
A predetermined amount of the polymer obtained by drying is put in tetrahydrofuran, left at room temperature (25 ° C) for 24 hours, then passed through an 80-mesh stainless wire net, and a polymer in a swollen state insoluble in THF remaining in the wire net And the dry weight of the polymer after evaporation of THF are calculated and calculated by the following formula.

The method for producing the conjugated diene-based copolymer rubber latex of the present invention is not particularly limited, and all the monomers to be used may be batch-charged into a polymerization vessel to be produced by one-step polymerization, or some monomers may be used. After the polymerization, the remaining monomers may be added and the polymerization may be continued by a two-stage polymerization method or the like.

The vinyl pyridine-conjugated diene-based copolymer rubber latex used in the present invention is used together with the copolymer rubber latex used in the first stage treatment to improve the heat resistant adhesion between polyester fiber and rubber. It is obtained by copolymerizing the same conjugated diene monomer, vinyl pyridine and optionally a monomer copolymerizable therewith as in the case of the conjugated diene-based copolymer rubber latex of the previous period by ordinary emulsion polymerization. . Although 2-vinylpyridine is preferable as vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, 5-ethyl-2.
-One or two or more kinds such as vinyl pyridine can be substituted.

As the other copolymerizable monomer, the same aromatic vinyl compound, aliphatic vinyl compound, methyl acrylate as described above,
Examples thereof include esters of unsaturated monocarboxylic acids such as ethyl acrylate and methyl methacrylate, and one or more of these are copolymerized as necessary.

The amount of conjugated diene monomer in the total monomer mixture used is usually 45 to 95% by weight, the amount of vinylpyridine is usually 5 to 35% by weight, and the amount of other monomers copolymerizable with them is usually Usually 0-30
% By weight.

From the viewpoint of initial adhesive force, the vinyl pyridine-conjugated diene-based copolymer rubber latex has a gel content of the copolymer rubber of less than 80%, preferably 70% or less, and a degree of gel swelling of 20 times or more, preferably 40% or less. More than double.

As the vinyl pyridine-conjugated diene copolymer rubber latex, a butadiene / styrene / 2-vinyl pyridine copolymer rubber latex which has been conventionally used for adhering fibers to rubber is preferably used.

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 there is no particular limitation. Also, 2,6-bis (2,4
It may be used in combination with a compound such as -dihydroxyphenylmethyl) -4-chlorophenol composition.

The adhesive composition used for treating the polyester fiber in the present invention is usually a resorcinol-based on a solid content of 100 parts by weight of a conjugated diene-based copolymer rubber latex or a vinylpyridine-conjugated diene-based copolymer rubber latex. Formaldehyde resin is mixed in an amount of 10 to 180 parts by weight (dry weight).

Further, a part of the copolymer rubber latex in the adhesive composition used in the present invention is a styrene-butadiene copolymer rubber latex and its modified latex, acrylonitrile-butadiene copolymer rubber latex and its modified latex, natural rubber latex. One or more of the above can be substituted.

There is no particular limitation on the method of treating the polyester fiber with this adhesive composition, and the treatment can be performed in the same manner as the known resorcinol-formaldehyde-copolymer latex adhesive.

In the present invention, the polyester fiber is first treated with an adhesive composition containing a conjugated diene-based copolymer rubber latex and then treated with an adhesive composition containing a vinylpyridine-conjugated diene-based copolymer rubber latex. What has been done is used.

The polyester fibers to which the method of the present invention is applied include linear polymer polyester fibers and the like. The fibers are usually yarns,
Cords, continuous filaments, cloth, etc. are used, but other forms are also possible.

(Effect of the Invention) The polyester fiber-rubber adhesion method of the present invention gives an initial adhesive force equivalent to that when a conventional adhesive is used, and is extremely remarkably heat resistant as compared with the case where a conventional adhesive is used. Since the strength and heat resistance of the fiber can be improved, it can be used for manufacturing tires, belts, hoses and the like using polyester fiber.

(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 1 150 parts of water, 0.1 part of tetrasodium salt of ethylenediaminetetraacetic acid, 5 parts of sodium lauryl sulfate, 0.5 part of sodium bicarbonate, 0.3 part of potassium persulfate and 100 parts of the monomers shown in Table 1 in total in an autoclave equipped with a stirrer. The mixture was charged and reacted at 50 ° C with rotary mixing. When a predetermined polymerization conversion rate was reached, the reaction was stopped by cooling to remove unreacted monomers and obtain latexes A and B. The gel and gel swelling degree of the polymer in these latexes were measured by the following methods.

Put 100 g of ethanol in a glass beaker and add about 10 g of latex while mixing with a magnetic stirrer. After stirring for 5 minutes to solidify, the ethanol is discarded, 100 g of distilled water is added, and the polymer is washed under stirring. After repeating washing with distilled water three times, the polymer is recovered and dried for 2 hours in a vacuum dryer set at 50 ° C. Next, 0.2 g of dried polymer and tetrahydrofuran (TH
F) Add 100g and leave at room temperature for 24 hours. Then pass through a 80 mesh stainless steel wire net, first determine the weight of the THF insoluble polymer in the swollen state together with the wire net, then dry the entire wire net and determine the weight of the THF insoluble polymer by weighing, gel content and gel The degree of swelling was determined.

Next, 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 while stirring. This is referred to as liquid (a).

Next, 100 parts of latex A was added to the liquid (a), and the mixture was reacted at 25 ° C. for 20 hours while stirring. Then Barca Bond E
(Vulkabond E, a product of Vulnax) was added in an amount of 35 parts. This aqueous solution was prepared to have a solid content concentration of 20%. This is designated as (I) -A liquid. Similarly, latex B was used (I) -B
A liquid (I) -C liquid using Nipol 2518FS (vinyl pyridine latex manufactured by Nippon Zeon Co., Ltd.) was prepared.

A polyester tire cord (1500d / 2) was immersed in a test single cord dipping machine using the liquids (I) -A, (I) -B and (I) -C.
After the immersion treatment, heat treatment was performed at 240 ° C. for 1 minute. This treated polyester tire cord was sandwiched between two natural rubber compounds produced according to the compounding recipe shown in Table 2, and at 120 ° C for 120%.
Press vulcanized for a minute.

After vulcanization, the cord was taken out from the rubber and the strength was measured. The strength of the cord before vulcanization is 22.5 kg (average of 20 cords).
However, after vulcanization, the strength reduction of 32% was observed in the treatment with the (I) -A solution and the (I) -C solution,
With the (I) -B solution treatment, the strength was reduced by 150%.

Next, the polyester tire cords treated with the above-mentioned (I) -A liquid and (I) -B liquid were respectively subjected to immersion treatment using the (I) -C liquid. After the treatment, heat treatment was performed at 240 ° C. for 1 minute. The treated polyester tire cord was sandwiched between natural rubber compounds prepared according to the compounding recipe shown in Table 2 and press-vulcanized. The adhesive strength between the tire cord and the rubber was evaluated by the T adhesive strength test method (measurement temperature 20 ° C., relative humidity 65%, pull-out test of 24 wires). (I) -A liquid,
The results are shown in Table 3 in comparison with the case where only one treatment with the (I) -B solution and the (I) -C solution was performed.

Table 2 Rubber compounding formula Natural rubber 100 parts Zinc white 5〃 Stearic acid 2〃 Sulfur yellow 2.5〃 FEF carbon black 45〃 Process oil 5〃 N-oxydiethylene-2-benzothiazylsulfenamide 1〃 2,2, 4-trimethyl-1,2-dihydroquinoline polymer 0.2
〃 From the results of Table 3, in the two treatments, when the first treatment was treated with a treatment liquid containing a copolymer latex having a gel content and a gel swelling degree outside the range of the present invention, the heat-resistant adhesive strength was increased. It turns out that there is no improvement.

Example 2 Copolymer latex D ~ 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.
N was produced. As in Example 1, using these latexes, the treatment liquid [(I) -D to (I) -N] was prepared by mixing with the (a) liquid and the VALCABOND E, and using these, polyester tire cords were obtained. Immersion treatment and heat treatment were performed. Using this treated tire cord, vulcanization adhesion with natural rubber was carried out in the same manner as in Example 1. The cord strength and the adhesive strength were measured and the results shown in Table 5 were obtained.

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Claims (1)

[Claims] 1. When vulcanizing and adhering a polyester fiber and a rubber, the polyester fiber is (1) firstly, the resorcinol-formaldehyde resin and the copolymer rubber have a gel content of 80% or more, and a gel swelling degree. Is 20 times or less, and then treated with a composition comprising a conjugated diene-based copolymer rubber latex, and (2) then treated with a composition comprising the resin and a vinylpyridine-conjugated diene-based copolymer rubber latex. A method for adhering polyester fiber and rubber, which is characterized in that