JPH11100744A - Production of polyester cord - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyester cord capable of maintaining its strength while keeping its adhesion and good in resistance to fatigue by imparting an adhesive selectively to the outermost layer, which is responsible for adhesion between the rubber and fiber of the cord, while imparting a water repellant to the single yarn inside of the cord, which takes no part in the adhesion, in order to prevent the adhesive from penetrating inward. SOLUTION: This method imparts 0.1 to 3.0 wt.% of a water repellant compound to a polyester fiber while it is being produced, twists the polyester fibers into a cord, immerses the cord in a solvent under a tension of 0.02 to 0.5 g/de for 2 to 20 s, and treats it to be adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester cord as a rubber reinforcing material, and more particularly, to a high-strength and fatigue-resistant material preferably used as a rubber reinforcing material for tires, hoses, V-belts and the like. The present invention relates to a method for producing a polyester cord having excellent properties.

[0002]

2. Description of the Related Art Polyethylene terephthalate and polyester fibers mainly composed of polyethylene terephthalate have excellent physical and chemical properties, are industrially produced in large quantities, and are extremely useful fibers which are frequently used in various fields. Also, it has been used as a very suitable material as a rubber reinforcing material.

However, when the polyester fiber is bonded to another substance, the molecular structure of the polyester has a low functionality, so that the conventional bonding method has a low adhesive strength, so that a sufficient effect cannot be obtained. I have. For this reason, in bonding with rubber, it is once treated with an epoxy compound or an isocyanate compound, and then treated with an adhesive made of resorcinol-formalin latex (RFL).

[0004] The adhesive treatment for bonding the polyester cord and the rubber is originally performed for the purpose of adhering the single fiber and the rubber located on the surface layer of the cord, and the cord is immersed in an adhesive treatment bath. The adhesive is applied to the surface layer of the cord by such a process.

However, when such an adhesive is applied, the adhesive does not only adhere to the surface layer of the cord, but also penetrates into the cord which is not originally involved in the adhesion due to the action of capillary action or the like. The adhesive that has reached the inside of the cord causes the single yarns of the adhesive-penetrated part to adhere to each other due to the curing of the adhesive in the subsequent heat treatment step, so that the degree of freedom between the single yarns in the cord decreases, and There was a problem that the single yarns stuck to each other.

[0006] Such a reduction in the degree of freedom of the single yarn lowers the uniformity of the single yarn inside the cord at the time of elongation, and further increases the distortion of the cord, so that the stress applied to the cord can be evenly dispersed. And the code weakens,
Further, there is a problem that the elongation, compression and bending fatigue of the cord are also reduced.

[0007] Various methods have been implemented to solve such problems. For example, a method of raising the cord tension when immersing the adhesive to prevent the adhesive from penetrating into the inside of the cord, or treating the cord or fabric after the adhesive treatment with sharp edges for softening and bonding the single yarn There is a method to increase the degree of freedom by loosening.

[0008] However, in the former method, even if the cord tension is increased, the effect is limited because the adhesive still penetrates due to the capillary phenomenon between the single yarns. If the tension is excessively increased, the physical properties of the cord are affected. Therefore, the quality is inferior. In the latter method, the degree of freedom of the single yarn is increased, but the improvement effect is not satisfactory because the surface of the single yarn is covered with a highly frictional adhesive. Therefore, there has been a demand for a method for producing a cord that maintains the reinforcing effect of the adhesive force and has good cord strength and fatigue resistance.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and selectively adheres only to a single yarn in the outermost surface layer to be involved in adhesion between rubber and fibers. By applying an agent to the single yarn inside the cord that is not involved in adhesion, water repellency is imparted to prevent penetration of the organic solvent by capillary action, thereby maintaining the strength of the cord while maintaining the adhesiveness and its resistance. An object of the present invention is to provide a method for producing a polyester cord having good fatigue properties.

[0010]

According to the present invention, in producing a cord using a polyester fiber, a water-repellent compound is added to the polyester fiber in the range of 0.1 to 3.0% by weight, and then the polyester fiber is treated with the water-repellent compound. The aqueous compound-provided polyester fiber is twisted to form a cord, and the cord is formed from
A method for producing a polyester cord, comprising: immersing in an organic solvent in which the water repellent compound is dissolved under a tension of 0.5 g / de for 2 to 20 seconds, and then performing an adhesive treatment.

Hereinafter, the present invention will be described in detail. In the present invention, the polyester fiber is a multifilament composed of polyethylene terephthalate and a polyester mainly composed of polyethylene terephthalate. Concentration) is not restricted at all.

The polyester fibers used in the present invention include:
It is important that 0.1 to 3.0% by weight of the water-repellent compound is provided. The application of the water-repellent compound can be performed at any stage in the spinning process, but if applied before the stretching heat treatment, scum may adhere to the roller due to the heat resistance and properties of the water-repellent compound, and the process condition may be deteriorated. . In addition, since the film formation of the water-repellent compound or the reaction proceeds due to the heat treatment at the time of stretching and the water-repellent performance is completely expressed, it is applied to the single yarn of the surface layer of the cord by a subsequent treatment in an organic solvent. It may be difficult to remove the water-repellent compound thus obtained, and the object of the present invention may not be achieved. For this reason, it is preferable that the application of the water repellent compound is performed together with the finish after the stretching heat treatment, and that the heat treatment is not performed thereafter before the immersion treatment performed in the organic solvent.

As the water-repellent compound, an acrylic acid ester containing a perfluoroalkyl group, a methacrylic acid compound, or a reactive silicone resin is used.
As long as it does not react with the agent used in the bonding treatment, it is generally used as a water-repellent compound, and there is no particular limitation on heat resistance and the like. It is preferable that these water-repellent compounds are provided in an amount of 0.1 to 3.0% by weight in the form of an emulsion. If the amount of the water-repellent compound is less than 0.1% by weight, sufficient water-repellent performance cannot be obtained, and the adhesive penetrates into the cord. Cannot be prevented, and the effect of the present invention cannot be obtained. On the other hand, if the adhesion amount exceeds 3.0% by weight, the yarn production stability decreases due to the accumulation of scum and the like, and stable winding on a bobbin becomes difficult, which is not preferable.

[0014] The polyester fiber provided with the water repellent compound is processed into a cord as follows.
That is, one or more of the polyester fibers to which the water-repellent compound has been imparted as described above are twisted together to give a raw cord, or the twisted yarn is further subjected to a twisting process.
A cord can be formed by twisting in the opposite direction to the twisted yarn by combining the above two or more. The number of twists at the time of the twisting process varies depending on the application, but can be appropriately selected from those conventionally used for each application.

Next, 0.02 to 0.5 g of the raw cord
/ De, preferably from 0.2 to 0.4 g / de, in an organic solvent dissolving the water-repellent compound under a tension of 2 to 2 g / de.
It is necessary to remove the water-repellent compound attached to the cord surface layer by immersion for 0 second. If the tension at the time of immersion is less than 0.02 g / de, the density of the single yarn in the cord immersed in the organic solvent becomes low, so that the organic solvent penetrates into the cord, and Even the water-repellent compound applied to the yarn is removed, and the effect of the water-repellent compound becomes insufficient. The tension during immersion is 0.5 g /
If the density exceeds d, the density of the single yarn in the cord becomes so dense that it is difficult to contact the organic solvent with all the single yarns on the outermost surface of the cord to be bonded. Although it has a strong remaining property and poor adhesiveness, it also affects the physical properties of the cord, resulting in poor quality. If the immersion time in the solvent is less than 2 seconds, the water-repellent compound applied to the single yarn of the surface layer of the cord cannot be sufficiently removed, so that a satisfactory adhesive strength cannot be obtained. Further, if the immersion time in the solvent immersion exceeds 20 seconds, the action of removing the water-repellent compound proceeds to the single yarn inside the cord, and for the reason described above, the cord strength and the fatigue resistance thereof may be obtained. Can not. If the water repellency is low, the water repellency can be improved by performing a heat treatment after the immersion treatment.

The organic solvent used in the present invention includes:
There is no particular limitation as long as it dissolves the water-repellent compound used, but those which can be easily removed by heating and drying are preferable. Such organic solvents include acrylic acid,
As the organic compound that dissolves the methacrylic acid compound, for example, acetone or the like is used, and for the reactive silicone resin, toluene, industrial gasoline, or the like can be used.

The cord immersed in the organic solvent as described above is subjected to an adhesive treatment, and a known method is used for the adhesive treatment. That is, it can be performed by a first-stage treatment using an epoxy compound or an isocyanate compound, a second-stage treatment with an adhesive composed of resorcin-formalin-latex (RFL), or the like.

[0018]

According to the present invention, a cord comprising a polyester fiber provided with a water-repellent compound is immersed in an organic solvent under the above-mentioned conditions to remove the water-repellent compound on the surface layer of the cord. It has been found that the water-repellent compound inside the cord can be left, and this is achieved by utilizing this. That is, at the time of the adhesive application treatment, the adhesive is applied only to the cord surface layer substantially involved in the adhesion to the rubber, and the action of the remaining water repellent prevents the adhesive from penetrating inside the cord. Thus, the strength retention and fatigue properties after the bonding process are improved while maintaining the adhesiveness that the cord should have.

[0019]

The present invention will be further described with reference to the following examples. The performance evaluation according to the embodiment is based on the following method.

Using a tensile load measuring device (manufactured by Shimadzu, Autograph), JI
Performed according to SL-1074-64.

Evaluation of Adhesion Five adhesive treatment cords were embedded in unvulcanized rubber at a temperature of 16
Vulcanization was carried out at 0 ° C. for 20 minutes under conditions of 65 kg / cm ² , and at the same time, it was adhered to rubber. This cord is measured and evaluated by a peel test method.

Fatigue evaluation One adhesive treatment cord was embedded in unvulcanized rubber at a temperature of 150.
JIS L-101 using a test specimen which was vulcanized at 50 ° C. for 30 minutes at 50 kg / cm ² and simultaneously bonded to rubber.
According to the disk fatigue (Goodrich method) of No. 7, the elongation rate was + 6.0% at room temperature, the compression rate was -12.6, and the number of times of fatigue was 1,000,000 times. Rate was evaluated.

Example 1 Polyethylene terephthalate having an intrinsic viscosity of 1.00 was melted, discharged from a 192 hole base, passed through a zone where heating and holding was performed, and then cooled by blowing cooling air along the blowing length. After solidification, a spinning oil agent: 0.3% by weight was applied with an oiling roller, and then wound at a speed of 800 m / min.

The obtained undrawn yarn is heated by a preheating roller and subjected to the first stage drawing at 3.4 times, followed by the second stage drawing at 1.5 times in a dry heat bath and relaxed by 3%. After that, using an oiling roller, Asahi Guard: LS-4142 [β- {perfluoroalkyl acrylate (C9-C13)}
Alkyl ethyl acrylate (C10-C18) copolymer, active ingredient: 20%, manufactured by Asahi Glass Co., Ltd.]: 1.0% by weight (active ingredient adhesion amount: 0.2% by weight)
By winding at a speed of 300 m / min, 1000 d
e, tensile strength: 9.0 g / de, tensile elongation: 13.
8% of polyester fibers were obtained.

Next, 490 times /
m, and the two twisted yarns are twisted together to form 490
Twist / m was twisted to obtain a raw cord. The raw code is set to 0.
The cord was immersed in acetone under a tension of 15 g / de for 5 seconds to remove the water-repellent compound on the cord surface. Next, the immersed cord was treated in an adhesive bath using an epoxy compound as a first adhesive and resorcinol-formalin latex as a second adhesive to obtain a polyester cord.

Example 2 A polyester cord was obtained in the same manner as in Example 1, except that the tension when immersed in an organic solvent was 0.3 g / de and the time was 15 seconds.

Comparative Example 1 A polyester cord was obtained in the same manner as in Example 1 except that a tension of 0.01 g / de was applied when immersed in an organic solvent.

Comparative Example 2 A polyester cord was obtained in the same manner as in Example 1, except that the polyester cord was immersed in an organic solvent for 0.5 seconds.

Comparative Example 3 A polyester cord was obtained in the same manner as in Example 1 except that a polyester fiber to which a finishing oil containing a water-repellent compound was not applied was used.

Table 1 also shows the evaluation results of the polyester cords obtained as described above. In Examples 1 and 2, both the adhesiveness and the strength retention rate after disc fatigue were good, but in Comparative Examples 1 and 3, the strength retention rate after disc fatigue was poor. In No. 2, the adhesiveness was poor and was not satisfactory.

[0031]

[Table 1]

Claims (2)

[Claims] In producing a cord using a polyester fiber, a water-repellent compound is applied to the polyester fiber in a range of 0.1 to 3.0% by weight, and then the polyester fiber provided with the water-repellent compound is twisted. To form a cord, immersing the cord in an organic solvent dissolving the water repellent compound under a tension of 0.02 to 0.5 g / de for 2 to 20 seconds, and then performing an adhesive treatment. Characteristic method of producing polyester cord. 2. The method for producing a polyester cord according to claim 1, wherein the application of the water-repellent compound is carried out after the drawing heat treatment of the polyester fiber, and thereafter, no heat treatment is carried out before the immersion treatment carried out in an organic solvent.