JP2651067B2 - Method for improving adhesion of polyester fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a method for producing a polyester fiber for reinforcing acrylic rubber, which is resistant to high-temperature vulcanization and secondary vulcanization, and has good cold resistance, oil resistance and heat resistance.

[0002]

2. Description of the Related Art Polyester fibers have high strength and high Young's modulus, and are extremely useful as rubber reinforcing fibers for tires, hoses, belts, and the like. on the other hand,
In the field of hoses, rubber materials are changing to have excellent high-temperature characteristics in terms of rubber materials, such as an increase in the temperature of an engine room of an automobile. One of them is acrylic rubber. The rubber is poor in reactivity, and it is extremely difficult to bond reinforcing fibers by a conventional method. That is, when polyester fiber is applied to these uses, the fiber surface is relatively inactive, so that at present, the adhesiveness to a matrix such as rubber or resin is insufficient.

A chemical treatment method using various chemicals, for example, a method of treating with a highly reactive chemical such as an epoxy compound or an isocyanate compound has been proposed and put into practical use.
The idea of using a chlorophenol compound, which is a good solvent for polyester fibers, as an adhesive component has been around for a long time, and has actually been used in the market as Vulkabond (manufactured by ICI) and Tamanol (manufactured by Arakawa Chemical Co., Ltd.). However, these conventional chlorophenol compounds are obtained by co-condensing parachlor and resorcinol with formaldehyde, and are represented in the same manner in terms of the structural formula, but as can be seen from the molecular weight distribution shown in FIG. Since it contains a large amount of unreacted resorcinol and parachlorophenol, there are problems in the working environment and the performance is not always sufficient.

[0004]

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 method for producing a polyester fiber having improved adhesion to an acrylic rubber matrix.

[0005]

That is, according to the present invention, after treating a polyester fiber with a first treating agent containing a special chlorophenol compound / resorcin / formalin / rubber latex, the resorcinol / formalin rubber latex (R)
FL), the special chlorophenol compound is a compound obtained by co-condensing parachlorophenol and resorcinol with formaldehyde, and is a trinuclear compound represented by the following structural formula (FL). I),
Fig. 2 shows pentanuclear (II) and heptanuclear (III) as main components .
It has a molecular weight distribution, the rubber latex of the first processing agent and the second processing agent is an acrylic rubber latex, and the acrylic rubber is an acrylic rubber having an alkyl acrylate as a main skeleton and cross-linked with an epoxy compound. This is a method for improving the adhesion of polyester fibers . The special chlorophenol compound referred to in the present invention is a compound obtained by co-condensing parachlorophenol and resorcinol with formaldehyde, and is represented by a trinuclear compound (I) represented by the following structural formula.
It is a special chlorophenol compound containing pentanuclear (II) and heptanuclear (III) as main components, and has a specific molecular weight distribution shown in FIG.

[0006]

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[0007] The acrylic rubber latex referred to in the present invention is an emulsion obtained by emulsifying an acrylate represented by the following structural formula with a surfactant.

[0008]

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The acrylic rubber referred to in the present invention is an acrylic rubber having an alkyl acrylate as a main skeleton and crosslinked with an epoxy compound.

[0010] RFL applied in the present invention is resorcinol.
A mixture of an initial condensate and a rubber latex obtained by reacting formalin under an alkali or acidic catalyst,
Regarding the mixing ratio of resorcinol, fermaline, and rubber latex, an effect can be obtained by applying any of the known techniques.

[0011]

The polyester fiber obtained according to the present invention contains a resorcinol-formalin rubber latex to which a special chlorophenol compound having less unreacted substances among chlorophenolic compounds which are good solvents of the fiber is added. After treatment with 1 treatment agent, immediately after treatment with an adhesive consisting of resorcinol-formalin rubber latex using acrylic rubber latex with high affinity for the acrylic rubber to be adhered, the first adhesion In the agent,
Due to the effect of the chlorophenol compound, a bond with the fiber is formed, and the latex polymer forms a network structure. Then, in the second adhesive, an acrylic rubber latex having a high affinity for the adhered rubber covers the fiber surface, and the adhesive property is improved. Is expressed. In particular, the acrylic rubber used here has an acrylic acid alkyl ester as a main skeleton and is crosslinked with an epoxy compound. It shows good performance, and vulcanization conditions are also high, even in high-temperature secondary vulcanization to express rubber physical properties. It is possible to obtain a highly durable adhesive performance with very little decrease in adhesive performance.

Hereinafter, the present invention will be described in detail with reference to Examples, but it should not be construed that the invention is limited thereto.

The various performances in the examples were evaluated by the following methods. 1) Molecular weight distribution of chlorophenol compound The molecular weight distribution of the chlorophenol compound is measured by vacuum-drying the compound, dissolving the obtained solid in tetrahydrofuran, and measuring by gel permeation chromatography or liquid chromatography. It is.
Although it depends on the characteristics of the column used, even if the dissolved concentration of the solid content is different, there is almost no difference in the obtained distribution shape. 2) Adhesive adhesion amount (SPU) The adhesion amount is determined from the weight difference before and after the adhesion treatment. 3) Adhesive performance (peeling adhesive strength between plies) 30 cords are arranged in one inch, and both sides are sandwiched between rubber sheets having a height of 0.4 mm. Two of them are stacked and vulcanized under predetermined conditions. Then, between the two layers with the code, 5
Peel at a speed of 0 mm / min and measure the adhesive strength at that time. At the same time, the state of adhesion of rubber after peeling is observed and ranked to determine the amount of rubber adhesion.

[0014]

Examples 1-3, Comparative Examples 1-3 Polyethylene terephthalate fiber (manufactured by Teijin Limited, [η] = 0.90) 150
Two multifilaments consisting of 0 de-250 fil were combined, and the lower strand was twisted 10 times / 10 cm to obtain a 3000 de single twist cord.

As the first treatment liquid, a special chlorophenol compound having a constant molecular weight obtained by co-condensing parachlorophenol and resorcinol with formaldehyde (aqueous ammonia solution of chlorophenol compound manufactured by Nagase Kasei Co., Ltd. 20 wt% aqueous ammonia dispersion of tri-, penta- and hepta-nucleates (Denabond) as a main component and rubber latex (40% aqueous emulsion of acrylic rubber latex, Nippol 854E, Nippon Zeon Co., Ltd.) ) And water in a weight ratio of 2: 1: 4.

On the other hand, 30 g of a 28% aqueous ammonia solution as a second treating agent was added to 260 g of water and stirred well, and in this aqueous solution, 60 g of a resorcinol-fermaline precondensate (40% solution of acetone) previously condensed with an acidic catalyst. Was added and sufficiently stirred and dispersed. Next, 340 g of rubber latex (a 40% aqueous emulsion of acrylic rubber latex), Nippol 854E and ZEON Corporation were added to water 2
After stirring well, the resorcinol-formalin initial condensate solution was added with slow stirring.
Next, 20 g of formalin solution (37%) was added to obtain an aqueous adhesive. This adhesive solution was aged at 20 ° C. for 48 hours.

After treating the polyester cord with the first treating agent, the polyester cord is dried at 130 ° C. for 90 seconds using a dipping machine.
Heat treatment was performed at 240 ° C. for 60 seconds.

Next, immersion treatment is performed in a second treatment agent,
Similarly to the case after the first treatment agent treatment, the resultant was dried at 130 ° C. for 90 seconds and then heat-treated at 235 ° C. for 60 seconds using a dipping machine.

The obtained adhesive-treated polyester cord is
It was embedded in an unvulcanized rubber mainly composed of an acrylic rubber having the composition shown in Table 1 and vulcanized at 150 ° C. for 30 minutes, and the peel adhesion between plies and the rubber adhesion after peeling were measured.

[0020]

[Table 1] The results are shown below.

[0021]

[Table 2]

The comparative example has a molecular weight distribution as shown in FIG. 1 described above, and contains unreacted resorcinol, a parachlorophenol-rich chlorophenol compound already contained therein, and generally, The acrylic rubber latex used is used. The composition according to the present invention has good balance in both adhesive peel strength and rubber adhesion rate.

[Brief description of the drawings]

Fig. 1 Molecular weight distribution of conventional phenolic compounds

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

Claims (1)

(57) [Claims] After treating a polyester fiber with a first treating agent containing a special chlorophenol compound, resorcin, formalin, and rubber latex, the polyester fiber is continuously treated with a resorcinol.
Second made of formalin rubber latex (RFL)
In the adhesion improving method of treating with a treating agent, the special chlorophenol compound is a compound obtained by co-condensing parachlorophenol and resorcinol with formaldehyde, and is represented by the following structural formula: trinuclear (I), pentanuclear (II), having a heptanucleotide (III) as a main component and having a molecular weight distribution shown in FIG.
Adhesion of polyester fibers, wherein the rubber latex of the first treatment agent and the second treatment agent is an acrylic rubber latex, and the acrylic rubber is an acrylic rubber having alkyl acrylate as a main skeleton and crosslinked with an epoxy compound. Improved method. Embedded image