JPH05148771A - Treatment of polyester fiber for reinforcing rubber - Google Patents

Abstract

PURPOSE:To obtain the subject fiber improved in long-term thermoresistant adhesion properties by adding a triazine compound to a mixture composed of a specified copolymer latex and a resorcin-formalin precondensate, applying the resultant first treatment and, after drying and heat treatment, applying the second treatment. CONSTITUTION:(A) The first treatment prepared by adding a triazine compound, a polyepoxy compound, a blocked isocyanate compound and/or an ethylenimine compound to a mixture of a conjugated diene-vinylpyridine copolymer latex containing an ethylenic unsaturated carboxylic acid monomer as a copolymer component and a resorcin-formalin precondensate is applied and, after drying and heat treatment, (B) the second treatment having a composition in which the polyepoxy compound is removed from the first treatment is further applied. Drying and heat treatment are subsequently carried out, thus the objective treatment of the rubber-reinforcing polyester fiber is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive treatment method for a polyester fiber material for rubber reinforcement. The present invention relates to a method for treating a polyester fiber material for rubber reinforcement, which suppresses deterioration of the fiber when it is embedded in and repeatedly subjected to extension and compression.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene rephthalate fibers are widely used as rubber-reinforcing fibers because of their excellent strength, modulus and dimensional stability.

However, since polyester fibers have poor adhesion to rubber, various methods for improving the adhesion between polyester fibers and rubber have been conventionally proposed.

Then, as an adhesive for increasing the adhesiveness between the polyester fiber and the rubber, a formulation using an epoxy resin, an isocyanate resin, a halogenated phenol resin, etc. has been developed and treated with these adhesives. Further, polyester fibers have come to be widely used as a reinforcing material for rubber products such as automobile tires, hoses and belts.

However, the polyester fiber which has been subjected to such a publicly known adhesive treatment, when considering its new application development, is exposed to a high temperature for a long time in a rubber product,
There is a problem that the adhesive force between the rubber and the polyester fiber is significantly reduced, that is, the heat resistant adhesive force is poor. Such poor heat-resistant adhesive strength makes it impossible to apply to tires, especially tires for large vehicles that generate a large amount of heat during running.

The poor heat-resistant adhesive strength is caused by deterioration of the polyester fiber itself due to the action of ammonia, amine, water, etc. generated from the rubber compound at high temperature,
It is attributed to the deterioration of the adhesive bond, and various improvement plans have been proposed for this.

As a typical conventional improvement plan, there are halogenated phenols such as 2,6-bis (2 ', 4'-dihydroxyphenylmethyl) -4-chlorophenol and resorcinol. A method (Japanese Patent Publication No. 46-11251) in which a reaction product of aldehyde and formaldehyde is added to and mixed with a liquid (RFL liquid) composed of a resorcin-formalin initial condensation product and rubber latex is mixed. .. However, according to this method,
The initial adhesive strength under normal temperature conditions is excellent, but the problem is that the heat-resistant adhesive strength when exposed to high temperature for a long time is extremely low, and the rubber adhesion rate in peel adhesion between plies is low. Had.

On the other hand, as disclosed in Japanese Patent Publication No. 60-22626, a mixed solution of an epoxy compound, blocked isocyanate and rubber latex is applied in the first treatment liquid, and RFL in the second treatment liquid. In the method of applying liquid,
The initial adhesive strength is relatively high, and the heat-resistant adhesive strength when exposed to high temperature is higher than that of the above formulation (Japanese Patent Publication No. 46-11251), but it is still not sufficient. Further, since the first treatment liquid has a high adhesion to the treatment cord after drying and heat treatment, stains on the turn roll of the treatment machine increase, and it is necessary to constantly clean it. Was difficult.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide excellent initial adhesive strength with rubber and heat-resistant adhesive strength, and strength.
It is an object of the present invention to provide a method for treating a polyester fiber for rubber reinforcement, which has improved fatigue resistance and can give a high-quality product.

[0010]

In order to achieve the above object, the method for treating a rubber-reinforcing polyester fiber according to the present invention comprises twisting the polyester fiber to form an untreated cord. A mixture (A) in which 2 to 10 parts by weight of a resorcin-formalin initial condensate is mixed with 100 parts by weight of a conjugated gen-vinyl pyridine copolymer latex in which an ethylene-unsaturated carboxylic acid monomer is copolymerized.
10 to 20 parts by weight of the polyepoxide compound (B) and 5 to 15 parts of the triazine compound (C) per 100 parts by weight.
20 to 40 parts by weight of the blocked polyisocyanate compound (D) or / and the ethyleneimine compound (E).
The first treatment liquid consisting of a mixture of parts by weight is applied, and subsequently dried at 70 to 150 ° C., and then 200 to 255 ° C.
A mixture of 12 to 25 parts by weight of a resorcin-formalin initial condensate per 100 parts by weight of a conjugated gen-vinyl pyridine copolymer latex copolymerized with an ethylenically unsaturated carboxylic acid monomer. (F) 100 parts by weight of triazine compound (C)
5 to 15 parts by weight of the blocked polyisocyanate compound (D) and / or 5 to 20 parts by weight of the ethyleneimine compound (E) are mixed to give a second treatment liquid, and subsequently 70 After drying at ~ 150 ° C, 200 ~
It is characterized in that heat treatment is performed at 255 ° C.

The polyester fiber used in the present invention means a form of filament yarn, cord, woven fabric and woven fabric made of polyethylene terephthalate or high molecular weight linear polyester mainly composed of ethylene terephthalate units. Is included.

The conjugated diene-vinylpyridine copolymer latex in which the ethylenically unsaturated carboxylic acid monomer contained in the first treatment liquid and the second treatment liquid in the present invention is copolymerized is a polybutadiene latex containing a styrene component. Copolymerized polybutadiene latex made by copolymerization,
Further, it is a quaternary copolymer obtained by copolymerizing vinyl pyridine and an ethylenically unsaturated carboxylic acid monomer component.

The polyepoxide compound (B) contained in the first treatment liquid in the present invention is a compound having two or more epoxy groups in one molecule, specifically, glycerol and pentaerythritol. Reaction products of polyhydric alcohols such as alcohol, sorbitol, ethylene glycol, polyethylene glycol, propylene glycol and polypropylene glycol with halogen-containing epoxides such as epichlorohydrin, bis- A polyepoxide compound obtained by oxidizing unsaturated bond moieties such as (3,4-epoxy-6-methyl-dicyclohexylmethyl) adipate and 3,4-epoxycyclohexene epoxide. Preferred are reaction products of polyhydric alcohols and epichlorohydrin (polyglycidyl ether compounds of polyhydric alcohols).

The triazine compound (C) contained in the first treatment liquid and the second treatment liquid in the present invention means cyanuric acid, isocyanuric acid, 2.4.6-ethyloyl-
It is characterized by using one kind or a mixture of plural kinds selected from S-triazine, triallyl isocyanurate and trihydroxyethyl isocyanurate.

The blocked polyisocyanate compound (D) and / or the ethyleneimine compound (E) contained in the first and second treating solutions in the present invention include tolylene diisocyanate and metaphene. Diisocyanate, diphenylmethane diisocyanate,
Polyisocyanate compounds such as hexamethylene diisocyanate and triphenylmethane triisocyanate, and phenols such as phenol, cresol and resorcin, lactams such as ε-caprolactam and valerolactam. , Acetoxime, methyl ethyl ketone oxime, oximes such as cyclohexane oxime, and a reaction product with a blocking agent such as ethylene imine. Among these compounds, particularly aromatic polyisocyanate compounds blocked with ε-caprolactam, and aromatic ethylene urea compounds such as diphenylmethane diethylene urea give good results.

First, the first bath treatment liquid will be described. Here, a conjugated gen-vinyl pyridine copolymer latex 1 in which an ethylenically unsaturated carboxylic acid monomer is copolymerized
A mixture (A) in which 2 to 10 parts by weight of the resorcin-formalin initial condensate is mixed with 100 parts by weight is used. In this mixture (A), the proportion of the resorcin-formalin initial condensation product is preferably 3 to 8 parts by weight,
More preferably, a novolak type condensate obtained by condensing resorcin-formalin under an acid catalyst is preferable.

In the mixture (A), if the amount of the resorcin-formalin condensate is less than 2 parts by weight, the processor will be contaminated, and if it is more than 10 parts by weight, the heat-resistant adhesive strength will be decreased, which is not preferable.

Further, the resorcin-formalin initial condensate is obtained under an alkaline catalyst, and the molar ratio of resorcin-formalin is preferably 0.75 to 2.00 mol of formalin per mol of resorcin, and more preferably It is preferably in the range of 0.75 to 1.50 mol. When using the resorcin-formalin novolak type condensate, it is preferable to dissolve it in an alkaline catalyst aqueous solution and then add formalin to obtain the same molar ratio as that of the resorcin-formalin initial condensate.

The first treatment liquid contains 10 to 20 parts of the polyepoxide compound (B) per 100 parts by weight of the mixture (A).
Parts by weight, 5 to 15 parts by weight of the triazine compound (C), 20 to 40 parts by weight of the blocked polyisocyanate compound (D) and / or the ethyleneimine compound (E). If it goes off, the object of the present invention cannot be achieved.

That is, the polyepoxide compound (B),
If the blocked polyisocyanate compound (D) and / or the ethyleneimine compound (E) is less than the above mixing ratio, the initial adhesive strength will be low, and if it is more than the above mixing ratio, the cord will be hard. Therefore, it is not preferable.

Further, if the content of the triazine compound (C) is less than the above-mentioned mixing ratio, a high heat-resistant adhesive force cannot be obtained, and if it is more than the above-mentioned mixing ratio, the rubber adhesion rate is lowered, which is not preferable.

The first bath treatment liquid usually has a solid content concentration of 5 to 20.
%, And the adhesion ratio to the polyester fiber is 2.5 to 6.0% based on the dry weight of the polyester fiber.

The heat treatment after applying the first treatment liquid is usually 200 to 200 ° C. after drying at 70 to 150 ° C. for 0.5 to 5 minutes.
It is performed at ˜255 ° C. for 0.3 to 5 minutes, but the drying can be omitted.

Next, the second bath treatment liquid will be described. That is, the second treatment liquid was resorcin-formalin based on 100 parts by weight of the conjugated gen-vinylpyridine copolymer latex obtained by copolymerizing the same ethylenically unsaturated carboxylic acid monomer as in the first bath treatment liquid. 12 to 2 initial condensate
A mixture (F) containing 5 parts by weight is used. More preferably, a novolak type condensate obtained by condensing resorcin-formalin under an acid catalyst is preferable. Resorcin-
The formalin initial condensate is obtained under an alkaline catalyst, and the molar ratio of resorcin-formalin is preferably 0.75 to 2.00 mol of formalin, and more preferably 0.75 to 0.75 mol, relative to 1 mol of resorcin. It is in the range of 1.50 mol. When using the novolac type condensate,
After being dissolved in an aqueous alkaline catalyst solution, it is preferable to add formalin so as to have the same molar ratio as that of the resorcin-formalin initial condensate.

5 to 15 parts by weight of the triazine compound (C), 5 to 20 parts of the blocked polyisocyanate compound (D) and / or the ethyleneimine compound (E) are added to 100 parts by weight of the mixture (F). High adhesive strength can be obtained by adding parts by weight.

The second bath treatment liquid usually has a solid content of 5 to 1
It is used at 5% and is treated so that the adhesion rate to the polyester fiber is 0.2 to 3.0% based on the dry weight ratio of the polyester fiber. The heat treatment after applying the second treatment liquid is usually after drying at 70 to 150 ° C. for 0.5 to 5 minutes,
The heat treatment is performed at 200 to 255 ° C. for 0.3 to 5 minutes, but the drying may be omitted.

The polyester fiber thus treated with the adhesive treatment liquid and heat treated is embedded in a rubber composition mainly composed of natural rubber or synthetic rubber, vulcanized under pressure, and It is firmly bonded.

[0028]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Each measured value is obtained by the following method.

T-initial adhesive strength and T-heat resistant adhesive strength: The treated cord was embedded in unvulcanized rubber and the initial adhesive strength under pressure was 150 ° C. for 30 minutes and the heat resistant adhesive strength was 170 ° C. for 70 minutes. After press vulcanization and cooling, the cord was pulled out from the rubber block at a rate of 30 cm / min, and the pulling load was expressed in Kg / cm.

Peel separation adhesion between plies (rubber adhesion rate, peeling force): A two-ply treated cord was embedded in rubber as a cross ply having an angle of 90 degrees (code driving density: 28 / inch). Press vulcanization is performed under pressure at 150 ° C. for 30 minutes, and after allowing to cool, both plies are peeled off at a pulling speed of 10 cm / min. The rubber adhesion rate is a code in which the code peeled from the rubber is visually observed, and the portion where the rubber is adhered to the surface of the code is expressed as a percentage, and the peeling force is the force required for peeling Kg / Expressed in 2 cm.

In the above adhesion evaluation, an unvulcanized rubber containing a carcass containing natural rubber as a main component was used as a rubber compound.

Fatigue resistance (Goodrich method disk fatigue): According to JIS L-1017 (1983).
That is, a rubber block filled with polyester fiber,
It is a 100% fraction showing the strength remaining ratio after being attached around two disks tilted so that the elongation rate is 5% and the compression rate is 15%, and subjected to repeated fatigue at 1705 rpm for 48 hours. The rubber compound used is the same as that used for the adhesion.

Code strength: Test length 25 using Tensilon
cm, and the pulling speed was 30 cm.

Examples 1 to 7 As the mixture (A) in the first treatment liquid, 0.7 mol of formalin was added to 1 mol of resorcin in the presence of caustic soda.
The resorcin-formalin initial condensate obtained by reacting 5 to 1.50 mol was reacted with 100 parts by weight of a conjugated diene-vinylpyridine copolymer latex in which an ethylenically unsaturated carboxylic acid monomer was copolymerized. A mixture obtained by mixing at a predetermined ratio shown in Table 1 and aging for 24 hours was used.

Then, to 100 parts by weight of this mixture (A), water was added to polyglycerol polyglycidyl ether and the mixture was emulsified using a homogenizer (B), and trihydroxyethyl isocyanurate was added to water. Dissolved in (C) and water of 4,4'-diphenylmethane diisocyanate (D) or diphenylmethane-bis 4,4'-N, N'-diethylimine (E) blocked with ε-caprolactam. The dispersions were mixed at a predetermined ratio shown in Table 1 to obtain a first treatment liquid having a solid content concentration of 15%.

On the other hand, the second treatment liquid was obtained by reacting 0.75 to 1.50 mol of formalin with 1 mol of resorcin in the presence of caustic soda, as in the first treatment liquid. The initial condensate is mixed with 100 parts by weight of a conjugated diene-vinyl pyridine copolymer latex in which an ethylenically unsaturated carboxylic acid monomer is copolymerized, at a predetermined ratio shown in Table 1, and aged for 24 hours. According to the mixture (F)
Got

To 100 parts by weight of this mixture (F), trihydroxyethyl isocyanurate dissolved in water (C) and diphenylmethane-bis 4,4'-N,
The N'-diethyleimine aqueous dispersion (E) was mixed at a predetermined ratio shown in Table 1 to obtain a second treatment liquid having a solid content concentration of 9%.

Polyethylene terephthalate having a yarn viscosity of 0.95 was melt-spun, and two 1,500 denier multifilaments drawn were twisted with a twist number of 40 times / 10 cm for upper twist and 40 times / 10 cm for upper twist. Then, it is used as a cord, dipped in the first treatment liquid (solid content amount of 4.0% by weight) using a computer processor (manufactured by Ritzler), and dried at 130 ° C. for 120 seconds. And then heat treated at 240 ° C. for 45 seconds.

Then, the substrate was immersed in the second treatment liquid (solid content of 0.8% by weight), dried at 100 ° C. for 100 seconds, and then heat-treated at 240 ° C. for 60 seconds.

The evaluation results of the obtained polyester fiber are shown in Table 1.

The symbol contents in Table 1 are as follows. X: Formalin (F) / resorcin (R) molar ratio Y: Resorcin-formalin initial condensation product blending ratio (parts by weight) B: Polyepoxy compound blending ratio (parts by weight) C: Triazine compound blending ratio (weight) Part) D: blending ratio of block isocyanate (parts by weight) E: blending ratio of ethylene urea compound (parts by weight) Y is a conjugated diene-vinyl pyridine copolymer in which an ethylenically unsaturated carboxylic acid monomer is copolymerized Polymer latex 100
It is a weight ratio with respect to parts by weight, and B, C, D and E represent the weight ratio with respect to 100 parts by weight of the mixture (A) and (F).

[0042]

[Table 1]

Comparative Examples 1 to 4 In the above Examples, the blending ratios of the resorcin-formalin initial condensate and the conjugated diene-vinyl pyridine copolymer latex obtained by copolymerizing the ethylenically unsaturated carboxylic acid monomer are shown in the table below. Except that it was changed as shown in 2.
The polyester fiber was treated under the same conditions as in the example (Comparative example 1).

Further, the polyester fiber was treated under the same conditions as in the above-mentioned examples except that the mixing ratio of trihydroxyethyl isocyanurate (C) was changed as shown in Table 2 (Comparative). Examples 2 and 3).

Further, in the above example, a vinylpyridine-styrene-butadiene terpolymer latex was used instead of the conjugated diene-vinylpyridine copolymer latex copolymerized with the ethylenically unsaturated carboxylic acid monomer. The polyester fiber was treated under the same conditions as in the example except that it was present (Comparative Example 4).

The evaluation results of the obtained polyester fibers are also shown in Table 2.

[0047]

[Table 2]

Example 8 The epoxy compound (B) in Examples 1 to 7 was used as a substitute for polyglyceryl polyglycidyl ether, polyglycidyl ether, glycerol polyglycidyl ether and sorbitol. The characteristics of the obtained polyester fiber are the same as those of Examples 1 to 7 even if the polyglycidyl ether is used.
Was almost the same.

[0049]

The polyester fiber treated by the method of the present invention has an initial adhesive force with rubber which is higher than that of the conventional method.
Heat resistance and fatigue resistance are improved, and durability is improved. The code strength is also improved as compared with the conventional method.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area D06M 15/55 // D06M 101: 32

Claims (1)

[Claims] 1. A method for treating a rubber-reinforcing polyester fiber, wherein the polyester fiber is twisted to form an untreated core.
This untreated cord was treated with 100 parts by weight of a conjugated gen-vinyl pyridine copolymer latex copolymerized with an ethylenically unsaturated carboxylic acid monomer and resorcin-
10 to 20 parts by weight of the polyepoxide compound (B), 5 to 15 parts by weight of the triazine compound (C), and 100 to 100 parts by weight of the mixture (A) obtained by mixing 2 to 10 parts by weight of the formalin initial condensation product, the blocked poly Isocyanate compound (D) and / or ethyleneimine compound (E)
The first treatment liquid consisting of a mixture of 0 to 40 parts by weight is applied, subsequently dried at 70 to 150 ° C., and then 200 to
Heat treatment was performed at 255 ° C., and then 12 to 25 parts by weight of a resorcin-formalin initial condensate was mixed with 100 parts by weight of a conjugated gen-vinylpyridine copolymer latex in which an ethylenically unsaturated carboxylic acid monomer was copolymerized. 5 to 15 parts by weight of the triazine compound (C) per 100 parts by weight of the mixture (F), and the blocked polyisocyanate
A second treatment liquid consisting of a mixture of 5 to 20 parts by weight of the compound (D) and / or the ethyleneimine compound (E), and subsequently dried at 70 to 150 ° C.,
A method of treating a polyester fiber material for rubber reinforcement, which comprises performing a heat treatment at 200 to 255 ° C.