KR20090131006A - Rubber composition for high-pressure hose with enhanced adhesive property to steel wire coated with brass - Google Patents

Abstract

PURPOSE: A rubber composition for high-pressure hose is provided to form a rubber layer adhered with a brass-coated steel wire used in a reinforcing layer of a high-pressure hose while not using expensive rubber such as chloroprene. CONSTITUTION: A rubber composition for high-pressure hose comprises NBR 100.0 parts by weight, PVC 10~50 parts by weight, and epoxy resin 1~15 parts by weight as an adhesive-imparting agent. The epoxy resin is a condensate between bisphenol A and epichlorohydron. The high-pressure hose comprises an inner layer(1), a reinforcing layer(2) formed on the inner layer, and an outer layer(3) formed on the reinforcing layer. The reinforcing layer of the high-pressure hose comprises brass-coated steel wire.

Description

Rubber Composition for High-Pressure Hose with Enhanced Adhesive Property to Steel Wire Coated with Brass}

The present invention relates to a high pressure hose comprising a rubber composition reinforced with a brass coated steel wire and an outer rubber layer formed by the composition, and more particularly, a high pressure hose sequentially comprising an inner layer, a reinforcing layer and an outer layer. It relates to a high pressure hose comprising a rubber composition for a high pressure hose used to form a rubber layer of the outer layer adhering to the brass coated steel wire contained in the reinforcing layer of the composition and the outer rubber layer formed by the composition.

Techniques for improving the mechanical strength of rubber products by inserting steel wires into rubber have been applied to tires and belts. Steel wire is usually coated with brass to improve adhesion with rubber and to prevent rust formation because the adhesion to rubber is not great. Various additives are used to improve the initial adhesion between the steel wire and the rubber and to suppress the deterioration of adhesion. Such additives include resins such as cobalt or cobalt salts and resorcinol. Korean Patent Publication No. 1993-7358 (1993. 08. 09.) discloses a method of improving adhesion to brass-coated iron wire by mixing squalene oxide with a compounding rubber.

The high pressure hose acts as a passage to withstand the high pressure of the fluid, such as gas or liquid flowing in the hose to move the fluid to a desired place, as shown in Figure 1, the inner layer (1), the reinforcing layer (2) And an outer layer 3.

The inner layer 1 and the outer layer 3 are mainly formed of compound rubber, and the reinforcing layer 2 is formed by weaving a reinforcing yarn in the form of a fabric on the inner layer 1 or a steel wire on the inner layer 1. It is formed by winding in a spiral of a predetermined angle, that is, by knitting in a woven. The steel wire used as the reinforcing material in the reinforcing layer 2 is usually coated with brass to prevent rust and improve adhesion to rubber.

In the high pressure hose having such a structure, in particular, a natural rubber or synthetic rubber may be used as the rubber layer of the outer layer directly bonded to the brass coated steel wire of the reinforcing layer, but the adhesion with the brass coated steel wire is not satisfactory. Therefore, in order to satisfy ozone resistance and weather resistance, the outer layer 3 generally needs to use expensive rubber such as chloroprene without double bonds. Therefore, there is a desire to produce a high pressure hose having satisfactory physical properties without using expensive chloroprene rubber.

Republic of Korea Patent No. 285667 (Announcement dated April 2, 2001) is a polyolefin resin, ethylene-acrylic acid ester rubber, which can be used to manufacture a high pressure hose excellent in durability and flexibility due to the strong adhesion to the brass coated steel wire reinforcement layer and A thermoplastic elastomer composition comprising an acid modified polyolefin resin is disclosed.

It is an object of the present invention to provide a rubber composition for a high pressure hose that is used to form a rubber layer that strongly adheres to the brass coated steel wire used in the reinforcement layer of the high pressure hose without using expensive rubber such as chloroprene.

It is also an object of the present invention to provide a high pressure hose in which a rubber layer strongly adhered to a brass coated steel wire used in a reinforcement layer of a high pressure hose, without using expensive rubber such as chloroprene.

The rubber composition for the high pressure hose of the present invention is used to form a rubber layer to bond with the steel wire coated with brass contained in the reinforcement layer of the high pressure hose including the inner layer, the reinforcement layer and the outer layer, NBR 100 parts by weight, PVC 10 to 50 parts by weight and 1 to 15 parts by weight of an epoxy resin as an adhesion promoter.

In addition, the high pressure hose of the present invention includes an inner layer, a reinforcing layer formed on the inner layer and an outer layer formed on the reinforcing layer, the reinforcing layer of the high pressure hose includes a steel wire coated with brass, and the outer layer is It has a rubber layer to adhere to the steel wire,

The rubber layer includes 100 parts by weight of NBR, 10 to 50 parts by weight of PVC, and 1 to 15 parts by weight of an epoxy resin as an adhesion promoter.

When the outer layer of the high pressure hose is formed with the rubber composition of the present invention, the outer layer has a high pressure hose having excellent qualities such as oil resistance, weather resistance, abrasion resistance, etc., due to its excellent adhesive strength with the brass coated steel wire included in the reinforcing layer of the high pressure hose. Can be obtained.

The rubber composition of the present invention is used to form a rubber layer directly bonded to the brass coated steel wire used in the reinforcement layer of the high pressure hose, 100 parts by weight of NBR, 10 to 50 parts by weight of PVC and epoxy resin 1 to 15 as an adhesion promoter. It includes parts by weight.

NBR (Nitrile Butadiene Rubber) used in the rubber composition of the present invention is a basic rubber component for forming the rubber layer of the inner layer and the outer layer of the high pressure hose. NBR is commonly understood as a copolymer of 2-propenenitrile and butadiene, but N-propenenitrile derivatives (e.g. 3-methyl-2-propenenitrile = 2-butenenitrile) and butadiene It can be understood to include copolymers and copolymers of acrylonitrile and butadiene. The NBR used in the present invention preferably has a weight average molecular weight in the range of 300,000 to 600,000, and its glass transition temperature is preferably in the range of -25 to -35 ° C.

The PVC used in the rubber composition of the present invention is to impart properties such as ozone resistance, weather resistance and wear resistance to the rubber composition of the present invention, and is used in an amount of 10 to 50 parts by weight based on 100 parts by weight of NBR. If the amount of PVC used is less than 10 parts by weight, it is not effective to obtain the above characteristics to be given by the PVC, if more than 50 parts by weight may cause problems such as reduced elasticity of the rubber is not preferable. The addition amount of PVC becomes like this. Preferably it is 10-30 weight part, More preferably, it is 15-30 weight part. The PVC used in the present invention preferably has a weight average molecular weight in the range of 150,000 to 300,000.

The epoxy resin used in the rubber composition of the present invention refers to a polymer compound containing two or more epoxy rings in a molecule and a resin produced by the ring-opening reaction of the epoxy group, and is not particularly limited as long as it is generally used as a resin. Representative examples thereof include condensates of bisphenol A and epichlorohydron, and the like. The epoxy resin serves as an adhesion promoter to improve the adhesion of the rubber to the brass coated steel wire in the composition of the present invention, it is preferable that 1 to 15 parts by weight based on 100 parts by weight of NBR. If the amount of the epoxy resin is too small, the role of adhesion improvement is insignificant, and in too many cases, deformation may occur depending on temperature. The epoxy resin is more preferably added in an amount of 2 to 10 parts by weight, and even more preferably in an amount of 3 to 5 parts by weight. It is preferable that the epoxy resin used in the present invention has an equivalent of 100 to 4,000 g / eq.

In addition to the above components, the rubber composition according to the present invention may further include carbon black, silica, or the like as an additive as an additive, and may further include hard coal, talc, and the like, and an anti-aging agent and a softener (plasticizer). . Such additives are generally added to a rubber composition for producing a rubber product such as a high pressure hose, and the amount thereof may be appropriately selected according to the desired use. In the rubber composition of the present invention including additives, the rubber component may be up to 50% by weight, and 30 to 50% by weight is conventional.

Organic compounds such as plasticizers or petroleum softeners added to the rubber composition of the present invention may be a factor in reducing the adhesive strength of the rubber composition, but by reducing the viscosity of the rubber composition to improve processability or decrease the hardness of the product after processing or It can be added to control the physical properties of the product. Such plasticizers are not particularly limited, and examples thereof include phthalate plasticizers, epoxy plasticizers, and phosphoric acid plasticizers.

Sulfur for vulcanization of rubber is mentioned as an additive which participates in the rubber composition of this invention. Proper vulcanization plays a role in controlling the physical properties of the rubber and can be appropriately used depending on the type of rubber used. The adhesion of rubber to brass-coated steel wire can be affected by the degree of vulcanization.

The rubber composition as mentioned above is the rubber layer of the inner layer 1 or the outer layer 3 of the rubber layer of the inner layer 1 directly adhering to the brass coated steel wire used in the reinforcement layer 2 of the high pressure hose shown in FIG. 1 and described above, In particular, it is used to form the rubber layer of the outer layer 3. In the high pressure hose of the present invention, the inner layer 1 may be formed of a high pressure hose inner rubber layer and a compound rubber including NBR rubber or a mixture of NBR and PVC having excellent oil resistance. In some cases, the inner layer 1 may be formed of the rubber composition of the present invention described above. In the high pressure hose of the present invention, the outer layer 3 may be formed of the rubber composition of the present invention as described above in order to obtain low cost while obtaining excellent ozone resistance, weather resistance and wear resistance.

Accordingly, the present invention provides a high pressure hose in which a rubber layer is formed by such a rubber composition to directly adhere to the brass coated steel wire of the reinforcing layer 2. Such a high pressure hose provides an advantage that the rubber layer is strongly adhered to the brass coated steel wire and has excellent quality such as durability while using inexpensive materials. Here, the brass coated on the steel wire preferably contains 57 to 85% by weight of copper, and 15 to 43% by weight except for copper may be zinc, or most of zinc and other metal components in a small amount.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

A rubber composition according to the present invention was prepared, which preferably comprises carbon black and the like as an additive but no plasticizer, and contains NBR, PVC and an epoxy resin. The content of the components of the rubber composition is listed in Table 1 below. Then, the brass coating steel wire is wound around the inner layer 1 formed of the rubber composition including NBR to form a reinforcing layer 2 by spiraling, and then the outer layer 3 is formed on the reinforcing layer 2 with the rubber composition prepared above. Formed. The adhesion to the reinforcing layer (2) of the outer layer (3) thus formed was carried out in accordance with the standard of ASTM D2229, the range of the strength value of the adhesive force appearing when the sample number n = 5 is shown in Table 1 below.

Comparative Examples 1 to 4

The same procedure as in Example 1 was performed except that only the adhesion promoter was changed in the rubber composition.

Table 1

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Adhesion Types Epoxy resin No addition cobalt Resorcinol Phenolic resin NBR 70 70 70 70 70 PVC 30 30 30 30 30 Adhesion promoter 3 0 3 3 3 IRB # 7 carbon black 40 40 40 40 40 ZnO 3 3 3 3 3 Stearic acid One One One One One sulfur 1.5 1.5 1.5 1.5 1.5 TBBS 0.7 0.7 0.7 0.7 0.7 Total (weight part) 149.2 146.2 149.2 149.2 149.2 Adhesive force (kgf / 1wire) 9.0-11.5 2.5 to 3.5 6.0-7.5 5.0 ~ 7.5 5.0 ~ 6.5

TBBS in the table is N-tert-butyl-2-benzothiazyl sulfenamide.

As shown in Table 1, the composition of NBR and PVC without the adhesive donor (Comparative Example 1) can be seen that the adhesion to the brass coated steel wire is very low, mainly used to improve the adhesion of the rubber in the tire It can be seen that the rubber composition to which cobalt (Comparative Example 2), resorcinol (Comparative Example 3) and phenolic resin (Comparative Example 4) were added as an adhesion promoter was improved to some extent. On the contrary, the rubber composition (Example 1) in which the epoxy resin is added as an adhesion promoter according to the present invention can be confirmed that the adhesion is significantly improved compared to the composition in which the adhesion promoter is not added. Compared with, the improvement of adhesion was clearly distinguished.

Example 2

The same procedure as in Example 1 was conducted except that a plasticizer was further added to the rubber composition. The content of the components of the rubber composition is listed in Table 2 below. In addition, the adhesive force was carried out according to the standard of ASTM D2229, the range of the strength value of the adhesive force appears when the sample number n = 5 is shown in Table 2 below.

TABLE 2

Example 2 Example 3 Comparative Example 5 Comparative Example 6 Comparative Example 7 Adhesion Types Epoxy resin Epoxy resin No addition Resorcinol Phenolic resin NBR 70 70 70 70 70 PVC 30 30 30 30 30 Adhesion promoter 5 5 0 5 5 IRB # 7 carbon black 40 40 40 40 40 CaCO3 40 40 40 40 40 DOP (plasticizer) 20 30 20 20 20 ZnO 3 3 3 3 3 Stearic acid One One One One One sulfur 1.5 1.5 1.5 1.5 1.5 TBBS 0.7 0.7 0.7 0.7 0.7 Total (weight part) 211.2 221.2 206.2 211.2 211.2 Adhesive force (kgf / 1wire) 8 ~ 10 7-10 2 ~ 3 4 ~ 7 4 ~ 6

TBBS in the table is N-tert-butyl-2-benzothiazyl sulfenamide.

As shown in Table 2, the addition of a plasticizer to the rubber composition can be seen that the adhesion is somewhat lower, the rubber composition of the present invention (Examples 2 and 3) even if the plasticizer further comprises an outer layer of the high pressure hose It can be applied effectively.

1: inner layer

2: reinforcing layer

3: outer layer

Claims (7)

100 parts by weight of NBR, 10 to 50 parts by weight of PVC, and 1 to 15 parts by weight of an epoxy resin as an adhesion promoter. The method of claim 1, The epoxy resin is a condensate of bisphenol A and epichlorohydron. The method of claim 1, The epoxy resin is a rubber composition, characterized in that the equivalent (Equivalent) range of 100 ~ 4,000 g / eq. The method of claim 1, The rubber layer formed by the rubber composition is characterized in that formed on the outer layer of the high pressure hose. A high pressure hose comprising an inner layer, a reinforcing layer formed on the inner layer, and an outer layer formed on the reinforcing layer, The reinforcement layer of the high pressure hose includes a steel wire coated with brass, The outer layer has a rubber layer that adheres to the steel wire, The rubber layer is a high pressure hose, characterized in that it is formed by including 100 parts by weight of NBR, 10 to 50 parts by weight of PVC and 1 to 15 parts by weight of epoxy resin as an adhesion promoter. The method of claim 5, wherein The epoxy resin is a high pressure hose, characterized in that the condensate of bisphenol A and epichlorohydron. The method of claim 5, wherein The epoxy resin is a high pressure hose, characterized in that the range of 100 ~ 4,000 g / eq equivalent (Equivalent).

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