KR100647410B1 - Deep polyester fiber for rubber reinforcement and adhesive composition thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dipped polyester fibers for rubber reinforcement and adhesive compositions thereof, wherein the carboxyl modified vinylpyridine (VP) latex is added to the adhesive composition to improve heat resistance of polyester fibers and rubber at high temperatures. It is to improve production and reduce production cost by one bath treatment.

Polyester, RFL, dipping, adhesive composition, carboxyl modified VP latex, general VP latex

Description

A dipped polyester fiber for rubber reinforcement and its adhesive composition}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dipped polyester fibers for rubber reinforcement and adhesive compositions thereof, particularly to improve heat resistance with rubber when exposed to high temperatures.

Polyester fibers represented by polyethylene terephthalate have excellent physical properties such as high strength and high modulus of elasticity, and thus are used as rubber reinforcing fibers such as tires, hoses and belts.

However, since polyester fibers have relatively inert surfaces, their adhesion with rubber is insufficient, so that their physical properties cannot be sufficiently exhibited.

For this reason, Japanese Patent Application Laid-Open No. 54-73994 has a chemical treatment method for treating the surface of polyester fiber with many compounds, for example, aliphatic epoxy compounds and blocked isocyanate compounds, such as highly reactive chemicals, for adhesion. A so-called two-bath treatment method has been proposed in which a treatment solution (usually referred to as RFL) consisting of a reaction product of ordinary resorcinol / formaldehyde and rubber latex is applied after application.                         

In addition, Japanese Patent Application Laid-open No. Hei 10-46475 proposes a method in which a blocked isocyanate compound and an aromatic epoxy compound are added to RFL and treated in one bath.

Another one bath treatment method is a method of treating halogenated phenol (typically PEXUL) by mixing with RFL, as proposed in Japanese Patent Application No. 46-11251.

Another method for treating polyester fibers is shown in US Pat. No. 3,234,067, which is treated with one bath consisting of an epoxy / isocyanate mixture followed by conventional RFL.

However, since the above methods use an excess of alkali compounds to increase the stability of RFL, hydrolysis occurs due to alkali compounds.

In addition, since the polyester fibers treated by these methods have poor heat resistance at high temperatures, there is a problem in that the amount of adhesion must be excessive in order to obtain sufficient adhesion.

However, if the adhesion amount is increased, the adhesive liquid penetrates excessively into the fiber and the stiffness of the fiber is increased to reduce the fatigue resistance.

In addition, the polyester fiber treated in this way, when exposed to high temperature, the decomposition of the fiber occurred by the catalytic action of the amine compound, which greatly reduced the strength and adhesion of the rubber.

Accordingly, the present invention provides an adhesive composition for preparing a rubber-reinforced polyester deep fiber having excellent adhesive strength retention at high temperature by adding carboxyl modified vinylpyridine (hereinafter referred to as VP) latex to the adhesive composition to solve the above problems. The purpose is to provide.

Another object of the present invention is to show a good adhesion to rubber even when exposed to high temperature while maintaining the original properties of the polyester fiber and at the same time can be treated in one bath to reduce the production cost of rubber reinforced polyester To provide the fibers.

The present invention relates to an adhesive composition of a deep polyester fiber for rubber reinforcement, wherein the adhesive composition is characterized in that carboxyl modified vinylpyridine (VP) latex is added.

The adhesive composition according to the present invention includes both general VP latex and carboxyl modified VP latex, and the general VP latex is made of vinylpyridine / styrene / butadiene rubber latex and may be any one containing no modified carboxyl group. .

General VP latex improves affinity with rubber and contributes to the improvement of initial adhesion.

Specific examples of general VP latex include 2518FS commercially available from Xeon, Japan, and VP 106 commercially available from Hyundai Petrochemical.

The carboxyl modified VP latex reacts with the amine compound contained in the rubber and prevents the amine compound from penetrating into the fiber, thereby preventing the polyester fiber from causing amine decomposition by the amine compound.                     

This results in a very good retention of adhesion when exposed to high temperatures.

As a result, even if heat is generated in the tire while the tire is running, the polyester fiber is stably bonded to the rubber structure, so that the durability and stability of the tire can be ensured, thereby producing a high quality tire.

Specific examples of the carboxyl modified VP latex include LX 603, 2518GL commercially available from Xeon, Japan, and V8Z22 commercially available from A & L, Japan.

In the present invention, the carboxyl modified VP latex is preferably 10 to 19% by weight relative to the solid content of the entire adhesive composition, it is preferable to use a carboxyl modified vinyl pyridine, styrene, butadiene terpolymer.

In addition, it is preferable that solid content ratio (weight ratio) of general VP latex / modified VP latex shall be 4-8.

When the carboxyl modified VP latex is less than 10% by weight relative to the solid content of the entire adhesive composition and the solid content ratio of the general VP latex / modified VP latex is less than 4, the heat resistance is excellent but the initial adhesion is poor. When the solid content ratio of the general VP latex / modified VP latex exceeds 8% by weight and the solid content exceeds 8, amine decomposition by the amine compound occurs when exposed to high temperature, making it difficult to obtain sufficient heat-resistant adhesion.

On the other hand, 2-vinyl pyridine is preferably used as the vinyl pyridine used to introduce the vinyl pyridine group. However, 3-vinyl pyridine, 4-vinyl pyridine, 2-methyl-5-vinyl pyridine, and 5-ethyl-2-vinylpyridine may be used. Species or more may be used.                     

The content of the vinyl pyridine group is 7-26% by weight, more preferably 11-23% by weight in the copolymer.

As a method of introducing a carboxyl group, the method of introducing into the ternary copolymer latex which copolymerized the ethylenically unsaturated acid monomer is mentioned.

The ethylenically unsaturated monomer is selected from unsaturated carboxylic acids such as acrylic acid, methacrylic acid and itaconic acid.

The carboxyl group may be introduced into the copolymer which is hydrolyzed after copolymerizing the ethylenically unsaturated monomer.

On the other hand, typical RF initial condensates include PEXUL or Denabond, which are representative compounds obtained by dissolving halogenated phenols such as 2,6-bis (2 ', 4'-dihydroxy phenylmethyl) -4-chlorophenyl in 5N ammonia water. Compounds such as E can be used.

The solids content of the whole adhesive composition of these compounds is at least 10%, preferably 20-30%.

If it is less than 10%, it is difficult to obtain sufficient initial adhesive force, and if it exceeds 30%, there may be a disadvantage that the adhesive composition is gelled.

The adhesive amount is preferably 4 to 6% by weight of the fiber based on the solid content.

If the adhesive adhesion amount exceeds 6%, the hardness of the adhesive liquid is increased, resulting in a decrease in the fatigue resistance of the cord, and if the adhesive adhesion amount is less than 4%, the adhesive strength between the rubber and the fiber is reduced. .

The reinforced polyester fiber for rubber reinforcement of the present invention can be produced in the following order.

Untreated polyester fibers are transferred to a dipping process to impart a treatment liquid to the fibers.

The treatment liquid applying method may be any method such as dipping, coating or spraying, but generally a dipping method is used.

The strength of the polyester fiber to be used is 0.05 to 0.20 g / d is suitable, and after the addition of the treatment liquid is subjected to a drying step.

The temperature at this time is 110-160 degreeC, and processing time is 20-150 second.

This is followed by heat treatment at 200 to 260 ° C. for 20 to 150 seconds to produce a diffused polyester fiber.

Since the prepared polyester fiber (deep cord) has excellent adhesive strength retention at high temperature, maintains the original properties of the fiber, and has excellent adhesion to rubber even after thermal aging, it is manufactured by one bath treatment. The price is low.

The reinforced polyester fiber (polyester deep cord) for rubber reinforcement according to the present invention has the following physical properties.

Below

Iii) initial adhesion; 11.5-15 kgf

                                   Ii) heat resistant adhesives; 7 to 11 kgf

                                   Iii) adhesion retention rate; More than 60%

Hereinafter, the structure and effects of the present invention will be described in more detail with specific examples and comparative examples, but these examples are only intended to more clearly understand the present invention, and are not intended to limit the scope of the present invention. .

Physical properties of the deep cords of Examples and Comparative Examples were evaluated in the following manner.

(a) adhesion

H-test was carried out to measure the initial adhesive strength and the heat-resistant adhesive strength at high temperature of the deep cord rubber prepared as described above.

H-test embeds both ends of the deep cord into a 9.5mm rubber block, maintains the gap between the rubber blocks of both ends at 9mm, and pulls the rubber blocks at both ends to separate the rubber and the cord. It is a method of evaluating adhesive force by measuring.

In addition, it is measured after vulcanizing for 20 minutes at 160 degreeC and the pressure of 25 kg / cm <^2> before adhesive strength evaluation, giving rubber sufficient strength.

The rubber composition used in the test was 100 parts of natural rubber, 3 parts of zinc oxide, 28.9 parts of carbon black, 2 parts of stearic acid, 7.0 parts of pintar, 1.25 parts of MBTS, 3 parts of sulfur, 0.15 parts of diphenyl guanidine and phenylbeta naphthylamine 1.0 part is mix | blended.

In addition, heat-resistant adhesive force measurement was measured at 170 degreeC and 60 minutes and the pressure of 25 kgf / cm <2>.

(b) adhesion retention rate

Adhesive force retention was calculated by the following equation.

<Example 1>

The polyester cord for tire reinforcement was twisted to 1,500 denier / 2 gops with 470 TPM, and the upper and lower edges were twisted to be the same. The obtained polyester cord was passed through the adhesive liquid prepared by the following method, and the adhesive liquid was provided.

After the adhesive liquid was added, it was dried at 150 ° C. for 120 seconds, and then heat treated at 240 ° C. for 2 minutes to terminate the adhesive treatment.

Adhesive liquid composition method

<A liquid>

Composition components Wet Dry 29.4 wt% resorcinol (part) 45.6 13.4 Pure water 255.5 - 37% formalin (part) 20 7.4 10wt% sodium hydroxide (part) 3.8 0.38 Subtotal (1) 324.9 21.18

After the solution A was prepared to have the composition as described above, the mixture was reacted with stirring at 25 ° C. for 5 hours, and then the following solution B was added.

<B amount>

Composition components Wet Dry 40 wt% VP 106 (part) 250 100 40 wt% LX 603 (part) 50 20 Pure water 129 - 28% ammonia water (part) 23.8 6.7 Subtotal (2) 452.8 126.7

Total = (1) + (2) 777.7 147.88

After addition of the liquid B was aged for 20 hours at 25 ℃ solid concentration was 19.0%.

<Example 2>                     

The same procedure as in Example 1 was repeated except that 2518GL was added instead of LX 603 as the carboxyl modified VP latex of Example 1.

The results are as shown in Table 1.

<Example 3>

The same procedure as in Example 1 was repeated except that V8Z22 was added instead of LX 603 as the carboxyl modified VP latex of Example 1.

The results are as shown in Table 1.

<Example 4>

The same procedure as in Example 1 was repeated except that 60 parts of LX 603 and 240 parts of VP 106 were added as the carboxyl modified VP latex of Example 1.

The results are as shown in Table 1.

Comparative Example 1

The same procedure as in Example 1 was repeated except that 300 parts of VP 106, a general VP latex, was added without using the carboxyl modified VP latex of Example 1.

The results are as shown in Table 1.

Comparative Example 2

The same procedure as in Example 1 was repeated except that 100 parts of VP 106, a general VP latex of Example 1, and 200 parts of LX 603, a carboxyl modified VP latex, were added.

The results are as shown in Table 1.

Comparative Example 3                     

The same procedure as in Example 1 was repeated except that 200 parts of VP 106, a general VP latex of Example 1, and 100 parts of LX603, a carboxyl modified VP latex, were added.

The results are as shown in Table 1.

<Table 1>

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Yarn Denier (d) 1500 1500 1500 1500 1500 1500 1500 Twist (top / bottom) (TPM) 470/470 470/470 470/470 470/470 470/470 470/470 470/470 Drying time (seconds) 120 120 120 120 120 120 120 Primary drying temperature (℃) 150 150 150 150 150 150 150 Secondary drying temperature (℃) 150 150 150 150 150 150 150 Heat treatment temperature (℃) 240 240 240 240 240 240 240 Heat treatment time (seconds) 120 120 120 120 120 120 120 General VP Latex / Modified VP Latex (weight ratio) 5 5 5 4 - 2 Content ratio of modified VP latex (wt%) 13.5 13.5 13.5 16 0 54 27 Initial Adhesion (kgf) 12 11.9 12.1 11.7 11.2 10.5 10.4 Heat-resistant adhesive force (kgf) 7.8 7.6 8.1 7.9 5.8 5.1 5.7 Adhesion Retention Rate (%) 65 64 67 68 52 49 55

The adhesive composition according to the present invention has excellent adhesive strength retention at high temperatures, maintains the original properties of the polyester fiber as it is, and has an advantage that can be treated in one bath while showing excellent adhesive strength to rubber even after heat aging.

Therefore, the reinforced polyester fiber for polyester reinforcement (polyester deep cord) of the present invention exhibits an initial adhesive force of 11.5 to 15 kgf, a heat resistant adhesive force of 7 to 11 kgf, and an adhesive strength retention of 60%.

Claims (4)

Dipped polyester fiber for rubber reinforcement having the following physical properties. next Iii) initial adhesion; 11.5-15 kgf                                    Ii) heat resistant adhesives; 7 to 11 kgf                                    Iii) adhesion retention rate; More than 60% RFL adhesive composition for dipped polyester fiber for rubber reinforcement, wherein the solid content of carboxyl modified vinyl pyridine (VP) latex is contained in an amount of 10 to 19% by weight based on the solid content of the entire adhesive composition. Adhesive composition for deep-polyester fibers. delete The adhesive composition for the reinforced polyester fiber for rubber reinforcement according to claim 2, wherein the weight ratio of the general VP latex solids / modified VP latex solids is 4 to 8.