KR20010046998A - A copolymer for adhesion between surfaces of steelcord and rubber - Google Patents

Abstract

The present invention relates to a copolymer produced by using vinyl acetate and trialkoxy vinylsilane as a substance causing bonding between the metal oxide layer and the polymer.

The structure of the copolymer prepared in the present invention is represented by the following formula (1), the polyvinylacetate portion is not only adhesive, but also excellent compatibility with the polymer, the polyalkoxy vinylsilane portion is crosslinked with the metal oxide layer and strong between the polymer It causes bonding and also brings together the flexibility of polyvinylacetate.

The present invention relates to a copolymer prepared by controlling the polymerization rate by controlling the polymerization ratio to 1: 1, the equivalence ratio, and the ratio of 1: 2 and 2: 1 equivalence as a manufacturing method for methoxy and ethoxy in polyalkoxy vinylsilane. It is about.

Description

A copolymer for adhesion between surfaces of steelcord and rubber

The present invention relates to a copolymer that can be used for bonding steel cord to rubber, and has a favorable compatibility as a polymer to a polymer with a rubber composition, and has an alkoxysilyl group that promotes interfacial adhesion between the steel cord and a metal oxide layer. It relates to a copolymer usable for adhesion between a steel cord and rubber, characterized in that.

Among the materials used for tire belts, steel cords play a very important role in maintaining tire stability while driving. However, when the interface adhesion between the steel cord and the rubber is reduced by the concentration of stress while driving, peeling may occur, which may cause an accident. Therefore, the method of improving the adhesion between the steel cord and the rubber can be very important.

As a method of improving interfacial adhesion, there is a method of increasing sulfur used in the vulcanization process of rubber. In the tire manufacturing industry, the vulcanization concentration in rubber is gradually increased to increase the binding of Cu _x S, and the vulcanization concentration of the belt portion which is in direct contact with the steel cord and vulcanize reaches 7-8 PHR. However, when the vulcanization concentration is increased, the hardness of the rubber is increased, which not only results in bad workability and physical properties of the tire, but also causes problems of blooming and environmental pollution.

Recently, in order to solve the above problems, research is being conducted to use steel cords including coupling agents having excellent adhesion to rubber, and processed using a separate coupling agent or plasma energy. The method of making superposition | polymerization in the inside is also reported. 1 shows a combination of a metal and a polymer formed in such a form.

Therefore, the present invention has developed a functional polymer copolymer having a basic polymer structure to replace the role of a separate coupling agent so as to promote adhesion at the adhesive interface between the metal oxide layer and the rubber of the steel cord. That is, in order to solve the problem of adhesion between the steel cord and the rubber bonding interface bonded with the existing coupling agent, the alkoxysilyl group which can be combined with the metal oxide layer and the functional group which can be bonded to the polymer layer can be bonded It aims at manufacturing the copolymer which can be used for the purpose.

1 is a schematic diagram of the binding form when using the binder.

2 is a schematic diagram of the bonding form when using a copolymer.

3 is a Si ²⁹ solid nuclear magnetic resonance analysis of the crosslinked structure.

The present invention is a copolymer having a polyacetate portion having excellent compatibility and adhesion with a polymer and an alkoxysilyl group capable of causing a crosslinked structure with an oxide layer on a metal surface, and is a copolymer which can be used for bonding steel cord and rubber. . That is, a high molecular compound that is functionalized to be applied to the adhesion of the steel cord and rubber, and has a favorable compatibility with the rubber composition from polymer to polymer, and an alkoxysilane that enhances the interfacial bonding force between the steel cord and the metal oxide layer. It contains groups.

The copolymer prepared in the present invention is synthesized by a radical polymerization reaction of vinyl acetate having a vinyl structure and a trialkoxy vinylsilane monomer, and by adding a radical initiator and reacting at 60 to 65 ° C. for 20 to 24 hours, the synthesized polymer A copolymer of polyvinylacetate and polytrialkoxyvinylsilane [poly (vinylacetate-co-trialkoxyvinylsilane)] is obtained. In addition, in the copolymer of the present invention, when the reaction equivalence ratio of Scheme 1 is controlled to 1: 1, 1: 2, and 2: 1, x and y respectively exhibit polymerization rates of 60:40, 30:70, and 80:20. Have

In the copolymer prepared in the present invention, the silyl group portion of the copolymer is bonded to the metal oxide layer, and the rubber layer is crosslinked with the copolymer to maintain a solid bond composition. The bonding composition of the copolymer prepared in the present invention with the rubber and the metal oxide layer is shown in FIG. 2. As shown in FIG. 2, the copolymer silyl group portion of the present invention is bonded to the metal oxide layer, and the portion including the vinyl group of the copolymer crosslinks with the rubber to be firmly bonded.

The cross-linked structure of the silane formed in the present invention can be confirmed by Si ²⁹ solid nuclear magnetic resonance analysis, and when the Si ²⁹ solid nuclear magnetic resonance analysis is performed on the polymer layer formed in the form as shown in FIG. Resonance peaks are found around -92ppm, -101ppm, -111ppm, and each peak represents Si (OSi) ₂ (OCH ₃ ) ₂ , Si (OSi) ₃ OCH ₃ and Si (OSi) ₄ .

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

14.1 ml of vinyl acetate and 25 ml of trimethoxy vinylsilane (R = CH ₃ ) are prepared and mixed in a stirring apparatus containing 300 ml of benzene solution. The agitating apparatus is allowed to reflux, and sufficiently creates a nitrogen atmosphere before the reaction, and then azobisisobutyronitrile, which is a reaction initiator for forming radicals when the temperature is raised to 60 to 65 ° C Add about 0.5g. This reaction is reacted for 20 hours in a nitrogen atmosphere. After completion of the reaction, the solution was concentrated sufficiently using a rotary evaporator, and the concentrated solution was precipitated in 2 L of methanol. The precipitate obtained is reprecipitated three times. The precipitate thus obtained is completely dissolved in a small amount of benzene, and then freeze-dried under reduced pressure to obtain a pure copolymer. At this time, the equivalence ratio of the reaction is 1: 1, and in Scheme 1, x and y are copolymers having a ratio of about 60:40.

Example 2

13.1 ml of vinyl acetate and 30 ml of triethoxy vinylsilane (R = CH ₂ CH ₃ ) are prepared and stirred in a stirring apparatus containing 300 ml of benzene solution. The stirring apparatus is allowed to reflux, and a sufficient nitrogen atmosphere is made before the reaction, and about 0.5 g of azobisisobutyronitrile, a reaction initiator, is added to form a radical when the temperature reaches 60 to 65 ° C. The reaction is reacted for 20 hours in a nitrogen atmosphere. After completion of the reaction, the solution was concentrated sufficiently using a rotary evaporator to precipitate the concentrated solution in 2 L of methanol. The precipitate obtained is reprecipitated three times. The precipitate thus obtained is completely dissolved in a small amount of benzene, followed by freeze drying under reduced pressure to obtain a pure copolymer. At this time, the equivalence ratio of the reaction is 1: 1, and in Scheme 1, x and y are copolymers having a ratio of about 60:40.

Example 3

14.1 ml of vinyl acetate and 50 ml of trimethoxyvinylsilane (R = CH ₃ ) are prepared and mixed in a stirring device containing 400 ml of benzene solution. The stirring apparatus is allowed to reflux, a sufficient nitrogen atmosphere is made before the reaction, and about 0.5 g of azobisisobutyronitrile, a reaction initiator, is added so that radicals are formed when the temperature reaches 60 to 65 ° C. The reaction is allowed to react for 20 hours in a nitrogen atmosphere. After completion of the reaction, the solution was concentrated sufficiently using a rotary evaporator, and the concentrated solution was precipitated in 2 L of methanol. The precipitate obtained is reprecipitated three times. The precipitate thus obtained is completely dissolved in a small amount of benzene, lyophilized under reduced pressure to obtain a pure copolymer. At this time, the equivalence ratio of the reaction is 1: 2, and in Scheme 1, x and y are copolymers having a ratio of about 30:70.

Example 4

As in Example 3, when reacting with triethoxy vinylsilane (R = CH ₂ CH ₃ ) by adjusting the equivalence ratio with vinyl acetate at 1: 2, x and y in Scheme 1 have a ratio of about 30:70. Copolymer.

Example 5

In Example 1, when vinyl acetate and trialkoxy vinylsilane (R = CH _3, R = CH ₂ CH ₃ ) was reacted with an equivalent ratio of 2: 1, x and y in Scheme 1 were about 80:20. It is a copolymer which has.

Resonance peaks confirmed by Si ²⁹ solid nuclear magnetic resonance analysis of the chemical cross-linking of the examples were found to be -92 ppm, -101 ppm and -111 ppm, and the peaks were Si (OSi) ₂ (OCH ₃ ) _{2 and} Si ( OSi) ₃ OCH ₃ , Si (OSi) ₄ . The results obtained through Si ²⁹ solid nuclear magnetic resonance analysis are shown in FIG. 3.

The copolymer according to the present invention has excellent compatibility with rubber, and can maintain strong bonds with alkoxysilyl groups with steel cords, showing improved adhesion compared to conventional rubber compositions, and being added in excess to enhance adhesion. Since the amount of sulfur can be greatly reduced, it is possible not only to produce environmentally less harmful products, but also to prevent problems such as deterioration of adhesive strength in post-processing due to blooming.

Claims (4)

A copolymer having a structure as shown in Formula 2, wherein the copolymer has a polyacetate portion having excellent compatibility and adhesion with a polymer, and an alkoxysilyl group capable of causing a crosslinked structure with an oxide layer on a metal surface. Formula 1 The copolymer according to claim 1, wherein x and y are polymerized to a level of 60:40 when the reaction equivalent ratio is 1: 1. The copolymer according to claim 1, wherein when the reaction equivalence ratio is 1: 2, x and y are polymerized to a level of 30:70. The copolymer according to claim 1, wherein when the reaction equivalence ratio is 2: 1, x and y are polymerized to a level of 80:20.