JPH07238473A - Method for bonding polyester fiber for high-pressure hose - Google Patents

Abstract

PURPOSE:To improve adhesiveness of a polyester fiber to a matrix rubber by treating a twisted polyester fiber with a treating solution containing specific components and then with a treating solution containing a chlorophenol of a specific structure, RFL and a specific cross-linking agent. CONSTITUTION:A twisted polyester fiber is treated with a first treating solution containing a polyepoxide compound (preferable example: a reaction product of a polyhydric alcohol and epichlorohydrin) and a terpolymer rubber latex of vinylpyridine/butadiene/styrene, then with a second treating solution comprising a rubber latex prepared by mixing a resorcin formalin rubber latex with specific chlorophenol compounds as specific chlorophenols which are prepared by condensing p-chlorophenol with resorcinol and formaldehyde and consist essentially of a trinuclear substance of formula I, a pentanuclear substance of formula II and heptanuclear substance of formula III, a terpolymer rubber latex of vinylpyridine/butadiene/ethylene and a polybutadine rubber latex in the ratio of 1/4 to 1/2 (weight ratio) and a block polyisocyanate as a cross- linking agent to improve adhesiveness to a matrix.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite of fiber and rubber, and more specifically, ethylene propylene rubber (EPD).
The present invention relates to a technique for adhering a polyester fiber for a high pressure hose having excellent adhesiveness between M) and the polyester fiber. Examples of products to which the adhesion treatment method of the present invention can be applied include products having a fiber reinforcing layer and a fiber base cloth, such as rubber hoses, diaphragms, V-belts, and conveyor belts, which are treated in a cord form. Is particularly preferable, and it is particularly useful as a polyester fiber for reinforcing a high-pressure rubber hose used for a flow path of a pressure fluid, in which it is important that there are few voids in the cord.

[0002]

2. Description of the Related Art Polyester fiber has high strength and high Young's modulus and is widely used as a rubber-reinforcing fiber for tires, hoses, belts and the like. As the temperature of the engine room has risen, there is a growing demand for rubber materials that have excellent high-temperature characteristics. One of them is ethylene propylene rubber, but it is extremely difficult to bond the reinforcing fiber by the conventional method because the rubber has few double bonds in the chemical structure and poor reactivity. Is. That is, when the polyester fiber is adhered to the ethylene propylene rubber, the polyester fiber is relatively inactive and the adhesiveness with the rubber matrix is insufficient. Therefore, a chemical treatment method using various chemicals, for example, a method of treating the polyester fiber cord with a highly reactive chemical chemical such as an epoxy compound or an isocyanate compound has been proposed. For example, "the polyester fiber material after stretching is treated with a first treatment agent containing a polyepoxide compound, and then treated with a second treatment agent containing an ethylene urea compound represented by the general formula and resorcin / formalin / rubber latex. A method for treating a polyester fiber material for rubber reinforcement, which is described in Japanese Patent Application Laid-Open No. 54-77794, "A linear aromatic polyester fiber is used as a polyepoxide compound (A), a blocked polyisocyanate compound (B) and a rubber latex (C). ) Is contained in the resorcinol-formalin-rubber latex (RFL), and then the ethylene urea compound (D) represented by the general formula and the epoxy-modified phenol condensate (E) represented by the general formula are uniformly added. Polyester fiber treated with a second treatment agent added in a weight ratio Processing method. "
(JP-A-60-99076), "150-260 after attaching an epoxy compound having at least two epoxy groups to a polyester-based synthetic fiber material.
A rubber latex was used, which was heat-treated at ℃ and was blended with an ethylene urea compound represented by the general formula in the subsequent step, a polybutadiene latex, and a terpolymer copolymer latex obtained by copolymerizing each component of styrene, butadiene and vinylpyridine. Treated with an adhesive solution containing resorcinol / formaldehyde latex, then 150-260 ° C
A method for improving the adhesiveness of a polyester-based synthetic fiber material for reinforcing an ethylene / propylene-based copolymer rubber composition, characterized in that the adhesive is heat-treated. (JP-A-60-219243) and the like are disclosed. However, even with these techniques, the adhesiveness of the polyester fiber to the ethylene / propylene copolymer rubber composition has not yet reached a sufficient level.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cord as a reinforcing fiber for a rubber hose used for a flow path of a pressure fluid, that is, a so-called high pressure hose. It is an object of the present invention to provide a method for producing a polyester fiber which itself can be used in a closed form and has improved adhesion to an ethylene-propylene rubber matrix.

[0004]

That is, according to the present invention, "a polyester fiber for a high-pressure hose is twisted and then treated with a first treatment agent comprising a polyepoxide compound and a vinyl pyridine / butadiene / styrene terpolymer rubber latex, and subsequently, Resorcin / Formalin / Rubber latex (RFL)
Is a compound in which parachlorophenol and resorcin are co-condensed with formaldehyde, and the trinuclear (I), pentanuclear (II) and heptad (III) represented by the following structural formula (Formula 2) The ratio of the special chlorophenol compound having the molecular weight distribution profile of FIG. 2 as the main component, the vinyl pyridine / butadiene / styrene terpolymer rubber latex and the polybutadiene rubber latex is 1/4 to 1
/ 2 (weight ratio) and a second treating agent comprising a rubber latex to which a blocked isocyanate compound is added as a cross-linking agent. It is.

[0005]

[Chemical 2]

The polyepoxide compound used in the first treatment agent of 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, and ethylene glycol, glycerol and sorbitol. Reaction products of polyhydric alcohols such as pentaerythritol and polyethylene glycol with halogen-containing epoxides such as epichlorohydrin,
Reaction products of polyhydric phenols such as resorcin / bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resins, resorcin / formaldehyde resins and the halogen-containing epoxides, unsaturated compounds with peracetic acid or hydrogen peroxide And polyepoxide compounds obtained by oxidizing
-Epoxycyclohexene epoxide, 3,4-epoxycyclohexenemethyl-3,4-epoxycyclohexenecarboxylate, bis (3,4-epoxy-6-
Methyl-cyclohexylmethyl) adipate and the like can be mentioned. Of these, 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. Such a polyepoxide compound is usually used as an emulsion. To prepare an emulsion or solution, for example, such a polyepoxide compound as it is, or a solution obtained by dissolving it in a small amount of solvent as necessary, a known emulsifier, for example, sodium alkylbenzenesulfonate, dioctylsulfosuccinate sodium salt, nonylphenolethylene oxide is used. Emulsify or dissolve using an adduct or the like.

The first treating agent comprises the above polyepoxide compound and a rubber latex obtained by terpolymerizing vinyl pyridine / butadiene / styrene. The compounding agent is not particularly limited, but the epoxy concentration in the treating agent is not limited. From the viewpoint of handleability, it is preferably 3% or less.

The solid content concentration of the first treating agent is preferably 1 to 30% by weight, more preferably 3 to 15% by weight of the fiber.
Used in%.

The blocked polyisocyanate compound used in the second treating agent of the present invention is an adduct of a polyisocyanate compound and a blocking agent, and the block component is liberated by heating to produce an active polyisocyanate compound. Is. Examples of the polyisocyanate compound include polyisocyanates such as tolylene diisocyanate, metaphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate and triphenylmethane triisocyanate, or two or more of these polyisocyanates and active hydrogen atoms. A terminal isocyanate group-containing polyalkylene glycol adduct poly obtained by reacting a compound having the same, for example, trimethylolpropane, pentaerythritol, etc., at a molar ratio of isocyanate group (-NCO) and hydroxyl group (-OH) exceeding 1. Examples thereof include isocyanate. In particular, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and polymethylene polyphenyl isocyanate are preferable because they exhibit excellent performance.

Examples of the blocking agent include phenols such as phenol, thiophenol, cresol and resorcinol, aromatic secondary amines such as diphenylamine and xylidine, phthalamides, lactams such as caprolactam and valerolactam, and the like. There are oximes such as acetoxime, methyl ethyl ketone oxime, and cyclohexane oxime, and acidic sodium sulfite.

RFL applied as the second treatment agent of the present invention
Is a mixture of an initial condensate obtained by reacting resorcin-formalin (RF) in the presence of an alkali or acidic catalyst, a special chlorophenol compound and rubber latex, and the mixing ratio of resorcin, formalin and rubber latex is a known technique. The effect can be seen by applying any of the above. The compounding ratio of these special chlorophenol compounds, resorcinol, formalin, and rubber latex slightly changes depending on the compounding of the adhered rubber. Generally, the mixing ratio of the aforementioned RF and the special chlorophenol compound is
50/50 to 80/20 (weight ratio) is preferably used.

The special chlorophenol compound used here is a compound obtained by co-condensing parachlorophenol and resorcin with formaldehyde, and has a trinuclear body (I) and a pentanuclear body (I) represented by the following structural formula (Formula 3). II) and 7-nuclear body (III) as a main component and having the molecular weight distribution profile shown in FIG. 2 (FIG. 1 shows a conventional molecular weight distribution profile). The rubber latex used in the second treatment agent is a blend of the rubber latex obtained by terpolymerizing vinylpyridine / butadiene / styrene used in the first treatment agent and the polybutadiene latex. The blending ratio of these rubber latexes needs to be changed according to the characteristics of the adhered rubber, but it is preferable to use terpolymer latex / polybutadiene latex = 1/2 to 1/4 (weight ratio).

[0013]

[Chemical 3]

The RFL applied in the present invention is resorcin
It is a mixture of an initial condensate obtained by reacting formalin under an alkali or acidic catalyst, a special chlorophenol compound, and a rubber latex, and any known technique is applied to the compounding ratio of resorcin, formalin, and rubber latex. However, the effect on the adhesiveness with ethylene propylene rubber is seen.

The present invention uses a polyester yarn having characteristics of elongation and heat shrinkage, and by applying an appropriate tension during the adhesive treatment and the subsequent heat treatment, it shrinks moderately, thereby reducing voids in the cord. Therefore, when used for reinforcing a high-pressure hose, a hose cord excellent in adhesiveness with ethylene propylene rubber, which is characterized in that fluid leakage and permeation are reduced, is obtained.

[0016]

The polyester fiber obtained according to the present invention has a surface coated with a treating agent containing an epoxy group,
Next, the second treating agent contains a rubber latex composed of polybutadiene and vinyl pyridine / styrene / butadiene terpolymer having a high affinity with the ethylene propylene rubber as the adhered rubber, and ethylene propylene having a high polarity in the structure. It is treated with an adhesive consisting of a special chlorophenol compound containing halogen, which has a high affinity for rubber. A rubber latex, which has a high affinity with the adhered rubber, covers the fiber surface, and the added cross-linking agent can enhance the cohesive strength of the adhesive layer, contributing to the improvement of heat resistance and the like, and exhibiting adhesiveness. . In particular, the role of many double bonds contained in the vinyl pyridine / styrene / butadiene terpolymer added to the polybutadiene rubber latex cannot be ignored.

As a result, first, in the first adhesive, the bond between the polyester fiber and the adhesive layer is strengthened, and in view of the physical properties of the applied yarn, the yarn shrinks during the adhesive treatment.
Since the voids inside the fiber bundle are reduced and the second treatment agent is applied on the fiber bundle by the dip method, it is possible to reduce the air diffusion property and obtain a cord with good adhesion to rubber. It will be possible. For example, after molding a hose, it is possible to prevent the penetration of various liquids, which are the pressurizing medium, from the end face of the hose into the reinforcing fiber layer in the hose fitting under the pressure conditions when using the hose. It is possible to obtain a treatment cord suitable for reinforcing a high-pressure hose, which is capable of greatly improving pressure and at the same time quickly transmitting pressure and the like. Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0018]

Examples 1 to 3 and Comparative Examples 1 to 7 Polyethylene terephthalate fiber having a strength of 5.8 g, an elongation of 23.0% and a heat shrinkage rate of 12.5% at 150 ° C. (manufactured by Teijin Limited, ultimate. A multifilament composed of 1500 denier 250 filament having a viscosity of 0.85 was twisted 8 times per 10 cm to obtain a cord. Then, a dip treatment was performed using the following first treatment agent.

As the first treatment agent, a polyepoxide compound (trade name: Denacol EX314; polyglycidyl ether manufactured by Nagase Kasei Co., Ltd.) and vinyl pyridine / styrene / butadiene terpolymer latex (trade name: Nipol 2518GL; Nippon Zeon Co., Ltd.) 5% aqueous dispersion in which the active ingredient ratio was 1: 1 was used.

The cord is dipped in the treatment solution, stretched at 2% and dried at 100 to 150 ° C. for 1 to 3 minutes,
Then, heat treatment was performed at 130 to 200 degrees for 1 to 3 minutes.

Next, as a second treating agent (RFL), 17 parts of resorcin and 14.9 parts of 37% formalin aqueous solution were reacted in 223.5 parts of water containing 13.3 parts of caustic soda to prepare an RF resin. Obtained. Next, vinyl pyridine / styrene / butadiene terpolymer latex (trade name: Nipol 2518GL; manufactured by Nippon Zeon Co., Ltd., solid content 40%) and polybutadiene rubber latex (trade name: Nipol LX111NF; Nippon Zeon stock) were added to this RF resin. Company made, solid content 55%) solid content ratio 1:
4 to 1: 2 (weight ratio 56.3 parts: 164 parts to 66.2)
(Parts: 96.3 parts) and then aged at room temperature for 24 hours. At this time, at the same time, an aqueous dispersion of a blocked polyisocyanate compound (trade name: DM60) was used as a crosslinking agent.
11; 45 parts of Meisei Chemical Co., Ltd., solid content 40%) was mixed. Immediately before use, a special chlorophenol compound (trade name: Denabond K; manufactured by Nagase Kasei Co., Ltd., solid content 20%) which is 4 times the solid content of RF resin is added,
Stir well before use. The control of the viscosity and the amount of adhesion of the treatment agent was adjusted by adding and diluting water to the treatment agent.

Immersion treatment is carried out in this second treatment agent, and 13
180-23 after drying at 0-160 ° C for 1-3 minutes
Heat treatment was performed at 5 ° C. for 1 to 2 minutes.

The resulting adhesive-treated polyester cord is
It was bladed at a crossing angle of 108 degrees, molded into a hose using ethylene propylene-based unvulcanized rubber, and steam-vulcanized at 150 ° C. for 40 minutes, and the peel adhesion strength and the rubber adhesion rate after peeling were measured.

Peel adhesion is the strength when the hose is cut to a length of 1 inch and the outer rubber is peeled along the circumference of the hose. The rubber adhesion rate is the blade cord after the outer rubber is peeled. The residual adhesion rate of the rubber on the top was determined.

Further, the air diffusion property (AD property) corresponding to the air permeability of the hose blade layer is obtained by placing four cords in a rubber bundle and vulcanizing them, and then applying them to the end surface of the vulcanization block. Air from one of the exposed cord bundles (3000 denier x 4) at a pressure of ² kg / cm ²
The amount of air permeated at that time was calculated from the change in water column pressure, and the amount of air passing through the voids in the cord was converted per minute.

The compounding composition of the rubber used for evaluation is as follows.

EPDM 100 parts HAF-carbon black 120 parts Process oil (porafine type) 90 parts Zinc white 5 parts Stearic acid 3 parts Vulcanizing agent 3.5 parts Vulcanization accelerator 2.5 parts Table 1 shows the results. Show.

[0028]

[Table 1]

Comparative Examples 1 to 4 and Examples 1 to 3 are the results when the polyester yarn treated by the method of the present invention was used, and Comparative Examples 5 to 7 have the physical properties of the polyester yarn to be applied according to the present invention. This is an example in the case of not depending on. Also,
In the comparative example, the case where the compounding ratio of the rubber latex is changed, the case where the special chlorophenol compound is not added and compounded, or the case where the crosslinking agent is not compounded is shown. According to the present invention, the air diffusion property (AD property), the adhesive peel strength, and the rubber adhesion rate are well balanced.

[Brief description of drawings]

FIG. 1 shows a conventional molecular weight distribution of a phenol compound.

FIG. 2 shows the molecular weight distribution of the special phenol compound according to the present invention.

Claims (1)

[Claims] 1. Twisted polyester fibers are treated with a first treatment agent comprising a polyepoxide compound and a terpolymer of vinylpyridine / butadiene / styrene terpolymer, followed by resorcin / formalin / rubber latex (RFL). A compound obtained by co-condensing parachlorophenol and resorcin with formaldehyde,
A special chlorophenol compound having a trinuclear body (I), a pentanuclear body (II), and a 7-nuclear body (III) represented by the following structural formula (Formula 1) as main components and having a molecular weight distribution profile shown in FIG.
A rubber in which the ratio of the vinyl pyridine / butadiene / styrene terpolymer rubber latex and the polybutadiene rubber latex is 1/4 to 1/2 (weight ratio), and a blocked polyisocyanate compound is added as a crosslinking agent. A method for adhering a polyester fiber for a high-pressure hose, which comprises treating with a second treatment agent comprising latex. [Chemical 1]