JPH11286876A - Method for producing polyester fiber for reinforcing rubber hose - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a polyester fiber capable of forming a flexible and excellent vibration damping hose and having improved adhesion to a rubber matrix. SOLUTION: When spinning or drawing a polyester fiber, it is treated with a treating agent containing a polyepoxide compound, and after forming a cord, it is treated with a treating agent containing a resorcinol-formalin rubber latex (RFL) or a chlorophenol compound. Gurley hardness of the treating agent code is 300
A method for producing a polyester fiber for reinforcing a rubber hose, which is treated so as to be not more than mg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyester fiber used for a rubber composite, and more particularly, to a method for producing a polyester fiber for reinforcing a rubber hose.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene terephthalate fibers have high strength and high Young's modulus, and are widely used as rubber reinforcing fibers for tires, hoses, belts, etc. as applications utilizing the same. I have. Above all, in the field of hoses, rubber materials having excellent high-temperature characteristics have been used so that they can be used for high-temperature applications such as engine rooms of automobiles, and required characteristics are changing. .

One of them uses an ethylene propylene rubber (EPDM). However, this rubber has very few double bonds in the chemical structure and has poor reactivity, so that it is very difficult to bond the rubber. In addition, an air conditioner hose or the like used in an engine room is required to have a vibration damping performance for absorbing engine vibration.

As a conventional method, a method using a highly polar chlorosulfonated polyethylene latex (see Japanese Patent Publication No. Hei 3-20136) and a method using a special chlorophenol compound (see Japanese Patent Application Laid-Open No. Hei 7-138880). Etc. have been proposed. However, when chlorosulfonated polyethylene latex is used, there is a problem that the polyester cord is liable to be thermally degraded. There are problems such as failure.

Further, when polyester fibers are adhered to rubber, the polyester fibers are relatively inert and have poor adhesion to a rubber matrix. Therefore, a chemical treatment method using various chemicals, for example, JP-A-54-7
As disclosed in JP-A-7794, JP-A-60-99076, JP-A-60-21924, etc., a method of treating a polyester fiber with a highly reactive chemical such as an epoxy compound or an isocyanate compound. Has been proposed. However, even with these methods, a stable adhesive effect could not be obtained.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and is capable of forming a hose which is flexible and has excellent vibration damping properties, and which has good adhesion to a rubber matrix. It is to provide an improved polyester fiber.

[0007]

According to the present invention, a polyester fiber is treated with a treating agent containing a polyepoxide compound at the time of spinning or drawing, and then formed into a cord, and then resorcinol-formalin rubber latex (RFL), chlorophenol-based When treated with a treating agent containing a compound, the rubber latex is mixed with a polybutadiene-based rubber latex and treated to reduce the Gurley hardness of the treated cord to 3
A method for producing a polyester fiber for reinforcing a rubber hose, characterized in that the content is not more than 00 mg.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
Examples of the polyester fiber used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and the like.The molecular weight of the polyester fiber, denier,
It is not limited at all by the number of filaments, cross-sectional shape, fiber properties, microstructure, presence or absence of additives, and polymer properties (terminal carboxyl group concentration, etc.).

The polyepoxide compound used as a treating agent in the present invention is a compound containing at least two epoxy groups per molecule in an amount of 0.2 g equivalent or more per 100 g of the compound. Such epoxide compounds are:
Reaction products of polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, and polyethylene glycol with halogen-containing epoxides such as epichlorohydrin;
-Hydroxyphenyl) dimethylmethane, phenol
Reaction products of polyhydric phenols such as formaldehyde resins and resorcin-formaldehyde resins with the above-mentioned halogen-containing epoxides, and polyepoxide compounds obtained by oxidizing unsaturated compounds with peracetic acid or hydrogen peroxide or the like.

Specific examples of the polyepoxide compound include 3,4-epoxycyclohexene epoxide,
4-epoxycyclohexenemethyl, 3,4-epoxycyclohexenecarboxylate, bis (3,4-epoxy-6-methyl-cyclohexylmethyl) adipate and the like. In particular, a reaction product of a polyhydric alcohol and epichlorohydrin, that is, a polyglycidyl ether compound of a polyhydric alcohol is preferable because it exhibits excellent performance.

These compounds are usually used as an emulsifying solution. To prepare an emulsifying solution or a solution, the compound may be used as it is or, if necessary, dissolved in a small amount of a solvent. For example, it is emulsified or dissolved using sodium alkylbenzenesulfonate, sodium salt of dioctylsulfosuccinate, adduct of nonylphenol ethylene oxide or the like.

[0012] The polyepoxide compound is applied together with a spinning oil and the like in a polyester fiber spinning process.
At this time, the adhesion amount of the polyepoxide compound is 0.1 to
Preferably used in the range of 5% by weight, more preferably in the range of 0.1 to 0.5% by weight. When the adhesion amount of the polyepoxide compound is less than 0.1% by weight, the effect of the polyepoxide compound is not sufficiently exerted, and satisfactory adhesiveness between the polyester fiber and the ethylene propylene rubber may not be obtained. On the other hand, if the adhesion amount of the polyepoxide compound exceeds 5% by weight, the fibers become very hard, which makes it difficult to impart the fibers in the yarn-making process, and also reduces the permeability of the treating agent to be treated in the next and subsequent steps. As a result, the adhesive performance is undesirably reduced.

In the present invention, the treatment with the polyepoxide compound is performed before the cord is formed using polyester fibers, and the cord is further subjected to an adhesive treatment using a resorcinol-formalin-rubber latex-based treating agent. Things. When the treatment with the polyepoxide compound is performed after the cord is formed, not only does the polyepoxide compound not sufficiently penetrate into the cord to improve the adhesiveness, but also the present invention seeks to obtain a hard cord itself. I cannot get flexible code.

Next, the treating agent containing resorcinol / formalin / rubber latex used in the present invention is resorcinol / formalin / rubber latex.
It is a mixture of an initial condensate, a special chlorophenol compound, a rubber latex, and a blocked polyisocyanate compound obtained by reacting formalin (RF) under an alkali or acidic catalyst. Any of the known techniques may be applied to the mixing ratio of resorcin, formalin, and rubber latex at this time.

The mixing ratio of the special chlorophenol compound and the resorcinol-formalin rubber latex varies slightly depending on the mixing ratio of the rubber to be adhered, but the mixing ratio of the RFL and the special chlorophenol compound is 50/50 to 8%.
0/20 (weight ratio) is preferred.

The special chlorophenol compound used here is a compound obtained by co-condensing parachlorophenol and resorcinol with formaldehyde, and is represented by the following trinuclear (I), pentanuclear (II), Those having a nucleus (III) as a main component are preferably exemplified.

[0017]

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As the rubber latex used as the adhesive treatment agent, a mixture of vinyl pyridine / styrene / butadiene terpolymer latex and polybutadiene latex is preferably used. The compounding ratio of these rubber latexes needs to be changed depending on the characteristics of the rubber to be adhered, but the compounding ratio of vinylpyridine / styrene / butadiene terpolymer latex / polybutadiene latex is in the range of 70/30 to 30/70 (weight ratio). Can be used. However, the composition is not particularly limited. The mixing ratio of resorcinol / formalin / rubber latex may be any of those known in the art.

Further, a usual blocked polyisocyanate compound is added to the adhesive treatment agent. The blocked polyisocyanate compound is an addition compound of a polyisocyanate compound and a blocking agent, and releases a blocking component by heating to produce an active polyisocyanate compound.

Examples of such a polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl polyisocyanate, and triphenylmethane triisocyanate; And a compound having two or more active hydrogen atoms, for example, trimethylolpropane, pentaerythritol, or the like, at a molar ratio in which the ratio of isocyanate group (—NCO) to hydroxyl group (—OH) exceeds 1 to obtain a terminal. An isocyanate group-containing polyalkylene glycol adduct polyisocyanate and the like can be mentioned. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and polymethylene polyphenyl isocyanate are preferred because they exhibit excellent performance.

Further, as the blocking agent, for example,
Phenols such as phenol, thiophenol, cresol and resorcinol; aromatic secondary amines such as diphenylamine and xylidine; lactams such as phthalic imides, caprolactam and valerolactam; oximes such as acetoxime, methyl ethyl ketone oxime and cyclohexane oxime And sodium acid sulfite.
These additives are usually used in an aqueous dispersion using a dispersant, and are added alone or in combination. The above-mentioned adhesive treatment agent is adjusted so as to contain 10 to 25% by weight of the total solid content.

The adhesion treatment agent can be applied to the polyester fiber material by any method such as contact with a roller or application or dipping by spraying from a nozzle.

The amount of solids adhered to the polyester fiber is preferably in the range of 0.5 to 10% by weight, more preferably 1 to 5% by weight, as the adhesive treatment composition. Further, squeezing by a pressing roller to control the solid content adhesion amount to the polyester fiber,
Means such as scraping off with a scraper or the like, blowing off with air blowing, suction, hitting with a beater, and the like can be used.

In the present invention, a so-called pre-processed yarn which has been previously treated with a processing agent containing a polyepoxide compound in a yarn-forming process is used, and the pre-processed yarn is twisted to form a cord, and then the above-mentioned treatment agent containing RFL is used. Processed at 80
At a temperature of ~ 180 ° C for 0.5-5 minutes, preferably 1-3
It is then dried at a temperature of 150 to 260 ° C., preferably 220 to 250 ° C. for 0.5 to 5.0 minutes, preferably 1 to 3 minutes. The heat treatment temperature is 80 ° C
If the heat treatment temperature is higher than 260 ° C., the polyester fiber is melted or fused, or becomes extremely hard, or the strength is deteriorated, and the strength is deteriorated. Will not be served.

The number of twists given to the cord varies slightly depending on the application, but the twist coefficient defined by the following equation is 0.1.
It is preferable to set the range of 5 to 2.0. Twist coefficient = {twist number [t / m] × {(de)} / 2874

The Gurley hardness of the cord thus treated is 300 mg or less, more preferably 200 mg.
It is important to: The Gurley hardness is 300
If the amount exceeds mg, the hose made using the cord is not flexible enough to absorb the inherent vibration generated in the automobile parts and the like, and the vibration damping properties of the hose used for the automobile parts and the like are obtained. I can't.

[0027]

The surface of the polyester fiber obtained by the present invention is thinly and uniformly coated with a treatment agent containing an epoxy group, and then coated with an adhesion treatment agent having an affinity for the rubber to be adhered. Even when an ethylene propylene rubber (EPDM) is used as the target rubber, the cord is very flexible while maintaining its adhesiveness.
A hose made using this cord has high flexibility, improves handleability at the time of attachment, and has very good vibration absorption.

[0028]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto. In addition, the characteristic evaluation method in an Example is as follows.

(1) Cord hardness The hardness of the cord is evaluated by the Gurley method.
It is measured by a method conforming to SL1086. A higher Gurley hardness value indicates a higher hardness.

(2) Cord Peeling Adhesive Strength Indicates the adhesive strength between the treated cord and the rubber. Twenty-five obtained cords are arranged in one inch, embedded in ethylene propylene unvulcanized rubber, and have a surface pressure of 5 kg. / Cm ^{2 at} a temperature of 80 ° C., and then covered with a polyester sheet and rubber so as not to be affected by moisture.
At 30 ° C. for 30 minutes. The force required to peel the cord from the rubber at a speed of 200 mm / min with this test piece is shown in kg / inch.

[Example 1] Resorcin-formalin initial condensate: Sumikanol 700S (Sumitomo Chemical Co., Ltd., 65% aqueous solution) reacted with an acidic catalyst in water containing an aqueous solution of caustic soda and aqueous ammonia, and then sufficiently added. Stir and disperse. Next, Nippol 2518FS (a water emulsion of vinyl pyridine / styrene / butadiene terpolymer manufactured by Zeon Corporation) and Nippol LX-111A2
(Polybutadiene rubber latex: 55% aqueous emulsion, manufactured by Zeon Corporation) (vinyl pyridine / styrene / butadiene terpolymer / polybutadiene rubber latex = 3: 7 (weight ratio)) was mixed with the resorcinol / formalin. 1: 4 in initial condensation dispersion and solid content ratio
(Weight ratio) and formalin with an R / F ratio of 1: 2
(Molar ratio) and mix uniformly. Next, Elastrone BN-69 was added to the RFL mixture.
(Diphenylmethane diisocyanate methyl ethyl ketone oxime block, 33% aqueous dispersion, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to RFL at a solid content ratio of 6: 1 (weight ratio), and the mixture was mixed at a temperature of 20 ° C. for 24 hours. Aged for hours. Immediately before use, Denabond E (a 20% solution of a special chlorophenol compound manufactured by Nagase Kasei Kogyo Co., Ltd.) was added to RFL and a solid content ratio of 2.5: 1 (weight ratio), and the mixture was sufficiently stirred and adjusted. . The viscosity and amount of the treatment agent were controlled by adding and diluting water to the treatment agent.

On the other hand, in the spinning process, a polyethylene terephthalate pre-treated yarn (manufactured by Teijin Limited; 1500 denier / 250
A single filament of [filament, [η] = 0.89) was twisted at 10 T / 10 cm to obtain a cord.

The cord was immersed in the above-described treating agent using a computer treater (manufactured by CA Ritzler Co., Ltd., tire cord processor), dried at a temperature of 170 ° C. for 2 minutes, and subsequently at a temperature of 235 ° C. Heat treatment is performed for 1 minute and further for 1 minute at 240 ° C. 3% by weight of the solid content of the treating agent adhered to the heat-treated polyester cord.

A test piece for evaluation was prepared using the processing code thus obtained. Table 1 shows the composition of the rubber used in the test piece for evaluation.

[0035]

[Table 1]

Table 2 shows the evaluation results of the obtained rubber hose.

[Comparative Examples 1 to 3] The case where the treatment agent conditions were changed as shown in Table 2 in Example 1 is shown. That is, Comparative Example 1 shows a case where all the rubber latex components in the treating agent were chlorosulfonated polyethylene rubber latex (CSM type), and Comparative Example 2 showed that a cord was formed using untreated polyester yarn. 1 shows a case where after treatment with a treatment agent having the following composition as a treatment agent, treatment with the adhesive treatment agent used in Example 1 was carried out. In Comparative Example 3, a cord was formed using untreated polyester yarn as in Comparative Example 2. After the same treatment as in Comparative Example 2 using the first treating agent, and then treated with a CSM-based rubber latex,
Other conditions were the same as in Example 1.

(First treating agent): polyepoxide compound /
A blocked isocyanate compound / vinylpyridine-styrene-butadiene copolymer latex is mixed at a solid content ratio of 1: 5: 3, and the concentration is adjusted so that the adhesion amount becomes 1.2% by weight. did. The processing conditions are 1
After drying at a temperature of 30 ° C. for 2 minutes, a heat treatment was performed at a temperature of 240 ° C. for 1 minute. The evaluation results are also shown in Table 2.

[0039]

[Table 2]

As is clear from Table 2, the adhesive according to the present invention was excellent in both adhesiveness and hardness. Example 1
And using the treatment cord obtained in Comparative Example 2, the blade was formed at a crossing angle of 108 °, formed into a hose using an ethylene-propylene-based raw vulcanized rubber, and steam-vulcanized at a temperature of 150 ° C. for 40 minutes. went. When the vibration damping properties of the hoses were evaluated, the vibration using the cord of Example 1 was reduced by about 2 db at the baseline compared with the one using the cord of Comparative Example 2 in the detection side.

Claims (1)

[Claims] 1. A polyester fiber is treated with a treating agent containing a polyepoxide compound at the time of spinning or drawing, and then treated with a treating agent containing resorcinol-formalin rubber latex (RFL) and a chlorophenol compound after forming a cord. A method for producing a polyester fiber for reinforcing a rubber hose, wherein a Gurley hardness of the treated cord is adjusted to 300 mg or less by mixing and treating a polybutadiene rubber latex with the rubber latex.