KR100985902B1 - The rubber composition for steel cord adhesion - Google Patents

Abstract

The present invention relates to a rubber cord adhesive rubber composition, and more particularly, in the rubber cord adhesive rubber composition, to include an acrylic ester (acrylic ester) can improve the adhesion to the steel cord It relates to a rubber composition for steel cord bonding.

Steel cords, adhesives, rubber compositions, acrylic esters

Description

Rubber composition for steel cord adhesion

The present invention relates to a rubber cord adhesive rubber composition, and more particularly, in the rubber cord adhesive rubber composition, to include an acrylic ester (acrylic ester) can improve the adhesion to the steel cord It relates to a rubber composition for steel cord bonding.

In general, steel cords used for tires are coated with brass having a copper (Cu) / zinc (Zn) ratio of 62/38 to 68/32 to provide adhesion to rubber.

On the other hand, the rubber composition for adhering to the steel cord coated with the brass to improve the adhesion to the steel cord uses a large amount of zinc oxide in order to suppress de-galvanization, resorcinol formaldehyde resin (resocinol formaldehyde resin, RFL) and Hexa methoxymethylmelamine (HMMM) are used to maintain adhesion with steel cords for a long time.

In addition, the adhesive rubber that bonds with the steel cord uses excessive sulfur in the rubber mixture to maintain the initial adhesive strength for a long time, and activates the copper ions in the brass as an adhesion promoter to facilitate the adhesive strength of the rubber. A small amount of cobalt salt is used to act as an activator to maintain adhesion. However, if the dispersion of sulfur and cobalt salt is not smooth, it plays a role of promoting the thermal aging of rubber by long-term storage or use, which may shorten the life of the rubber. Cyrez- of hexamethoxymethylmelamine (HMMA) system If 964 (HMMA 65% + Hydrated silica 35%) is used, there is a problem with the response of environmental products.

The present invention is to provide a rubber composition for the steel cord adhesion that can improve the adhesion with the steel cord.

The present invention relates to a rubber composition for attaching steel cords, and more particularly, in a steel composition for attaching steel cords, comprising an acrylic ester to improve the adhesion to steel cords. It relates to a rubber composition.

In the present invention, the rubber composition for bonding the steel cord is a conventional rubber composition for bonding the steel cord, and instead of the conventional hexamethoxymethylmelamine or hexamethoxymethylmelamine (HMMA) Cyrez-964 acrylic ester (acrylic ester) is used. This improves the adhesion to the steel cord and can solve the environmental problems caused by Cyrez-964 of hexamethoxymethylmelamine or hexamethoxymethylmelamine (HMMA).

The present invention shows a rubber composition for the steel cord adhesion improved adhesion to the steel cord.

The present invention relates to a steel cord adhesive rubber composition comprising 1 to 5 parts by weight of acrylic ester with respect to 100 parts by weight of the rubber raw material rubber composition.

The raw material rubber in the steel cord adhesive rubber composition of the present invention may be any one or more rubber selected from the group of natural rubber and synthetic rubber.

In the rubber composition for bonding the steel cord of the present invention, when the raw rubber is a mixed rubber in which natural rubber and synthetic rubber are mixed, natural rubber and synthetic rubber may be mixed rubber mixed in a weight ratio of 1: 9 to 9: 1. have.

Synthetic rubber that can be used as a component of the raw material rubber is styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), modified butadiene rubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, fluorine rubber, Silicone rubber, nitrile rubber, hydrogenated nitrile rubber, nitrile butadiene rubber (NBR), modified nitrile butadiene rubber, chlorinated polyethylene rubber, styrene ethylene butylene styrene (SEBS) rubber, ethylene propylene rubber, ethylene propylene diene (EPDM) rubber , Hypalon rubber, chloroprene rubber, ethylene vinyl acetate rubber, acrylic rubber, hydrin rubber, vinyl benzyl chloride styrene butadiene rubber, bromomethylstyrene butyl rubber, maleic acid styrene butadiene rubber, carboxylic acid styrene butadiene rubber, epoxy isoprene Rubber, maleic acid ethylene propylene rubber, carboxylic acid nitrile butadiate It may be at least one selected from the group consisting of rubber and BIMS (brominated polyisobutyl isoprene-co-paramethyl styrene).

Rubber cord adhesive composition of the present invention is less than 1 part by weight of acrylic ester (acrylic ester) with respect to 100 parts by weight of the raw material rubber or a problem that the adhesion to the steel cord is reduced, when used in excess of 5 parts by weight The use of excess acrylic acid ester may reduce the physical properties of the rubber composition. Therefore, it is preferable to use 1 to 5 parts by weight of acrylic ester with respect to 100 parts by weight of the raw material rubber in the steel cord adhesive rubber composition of the present invention.

In the above, the acrylic acid ester may be one represented by the following formula (1).

CH ₂ = CHCOOR ...... (1)

In Formula (1), R is any one selected from methyl group, ethyl group, butyl group and 2-ethylhexyl group.

Rubber cord adhesive composition of the present invention is a carbon black, syndiotactic-1,2-polybutadiene (syndiotactic-1,2) as a reinforcing filler (hereinafter, abbreviated as filler) to improve the reinforcement of the rubber composition at least one selected from the group consisting of polybutadiene (SPB), silica, titanium oxide, clay, layered silicate, tungsten, and talc. 30-80 weight part can be used with respect to a weight part.

If the filler is used in an amount less than 30 parts by weight based on 100 parts by weight of the raw material rubber, the reinforcement improvement is insignificant. When the filler is used in excess of 80 parts by weight, the physical properties of the rubber composition may be reduced. Therefore, it is preferable to use 30 to 80 parts by weight of the filler for the steel cord adhesive rubber composition of the present invention based on 100 parts by weight of the raw material rubber.

Among the above fillers, syndiotactic-1,2-polybutadiene (SPB) may have a diameter of 0.01 to 0.1 µm and a specific surface area of 80 to 90 m ² / g.

Among the above fillers, syndiotactic-1,2-polybutadiene (SPB) may have a diameter of 1 to 10 µm and a specific surface area of 100 to 120 m ² / g.

Among the fillers described above, carbon black may have a particle diameter of 20 to 30 nm.

Among the above fillers, carbon black may be one having an iodine adsorption value of 70 to 90 mg / g.

Among the above fillers, carbon black may have a DBP adsorption value of 80 to 120 mg / 100 g.

Of the above fillers, carbon black may have a particle diameter of 20 to 30 nm, an iodine adsorption value of 70 to 90 mg / g, and a DBP adsorption value of 80 to 120 mg / 100 g.

Among the fillers above, silica may be one having a BET adsorption value of 160 to 180 (m ² / g).

Among the above fillers, silica may be one having a DBP adsorption value of 190 to 210 (ml / 100g).

Among the fillers, silica may be one having a micropore volume of 0.015 to 0.020 (cc / g).

Among the fillers, silica may be one having a BET adsorption value of 160 to 180 (m ² / g), a DBP adsorption value of 190 to 210 (ml / 100 g), and a micropore volume of 0.015 to 0.020 (cc / g).

The present invention includes a rubber made of the above-mentioned steel cord adhesive rubber composition.

The present invention includes a tire containing a rubber made of the above-mentioned steel cord adhesive rubber composition.

The tire containing a rubber made of the above-mentioned steel cord adhesive rubber composition represents at least one selected from the group of passenger car tires, truck tires, bus tires, motorcycle tires and aircraft tires.

In the steel cord adhesive rubber composition of the present invention, the steel cord adhesive rubber composition is applied according to various components, contents, conditions, etc., in order to achieve the object of the present invention, the steel cord adhesive rubber under the conditions mentioned above The composition is preferred.

The steel cord adhesive rubber composition according to the present invention may contain various additives such as activators, anti-aging agents, process oils, vulcanizing agents, and vulcanization accelerators, which are used in conventional rubber cord adhesive rubber compositions in addition to the above-mentioned raw rubbers, acrylic esters and fillers. If necessary, it can be used in a predetermined amount by appropriate selection. However, these are not the essential components of the present invention as a general component used in the conventional rubber cord adhesive composition will not be described in detail below.

Hereinafter, the present invention will be described by the following examples, comparative examples and test examples. However, these are not limited to the scope of the present invention by these as an embodiment of the present invention.

Comparative Example

0.8 parts by weight of cobalt salt containing natural black as a raw material rubber, 60 parts by weight of carbon black, 10 parts by weight of zinc oxide, 23% cobalt, and resorcinol formaldehyde resin (resocinol formaldehyde resin) , RFL) 2 parts by weight, hexamethyl methoxymethyl melamine (HMMM) 3 parts by weight, stearic acid (0.8 parts by weight), antioxidant (Kumanox-13, Kumho Petrochemical) 2.0 parts by weight, process oil 4.0 parts by weight Banbury mixer (Banbury Mixer) and mixed for 30 minutes at 140 ℃ to obtain a rubber compound.

5 parts by weight of sulfur as a vulcanizing agent and 0.7 parts by weight of N, N-dicyclohexyl-2-benzothiazole (DCBS) as a vulcanization accelerator were added to the rubber mixture obtained above, and 160 ° C. Rubber specimens were prepared by vulcanization at 25 minutes at.

In the carbon black, a particle diameter of 25 ± 1 nm, an iodine adsorption value of 85 ± 2 mg / g, and a DBP adsorption value of 100 ± 5 mg / 100 g were used.

Table 1 below shows the components of the rubber specimens together.

≪ Example 1 >

0.8 parts by weight of cobalt salt containing natural black rubber, 60 parts by weight of carbon black, 10 parts by weight of zinc oxide, 23% cobalt, and 100% by weight of the raw material rubber, resorcinol formaldehyde resin (RFL) Parts by weight, 1 part by weight of acrylic ester, 0.8 parts by weight of stearic acid, 2.0 parts by weight of anti-aging agent (Kumanox-13), 4.0 parts by weight of process oil in a Banbury mixer and mixed at 140 ° C. for 30 minutes. A rubber compound was obtained.

5 parts by weight of sulfur as a vulcanizing agent and 0.7 parts by weight of N, N-dicyclohexyl-2-benzothiazole (DCBS) as a vulcanization accelerator were added to the rubber mixture obtained above, and vulcanized at 160 ° C. for 25 minutes to prepare a rubber specimen. It was.

In the carbon black, a particle diameter of 25 ± 1 nm, an iodine adsorption value of 85 ± 2 mg / g, and a DBP adsorption value of 100 ± 5 mg / 100 g were used.

In the above, acrylic acid ester was used as the formula (2).

CH ₂ = CHCOOCH ₃ ...... (2)

Table 1 below shows the components of the rubber specimens together.

<Example 2>

A rubber specimen was prepared in the same manner as in Example 1, except that 3 parts by weight of acrylic acid ester was used.

Table 1. Comparative Examples and Examples Rubber composition (unit: parts by weight)

 Item Comparative example Example 1 Example 2 Natural rubber 100 100 100 Zinc oxide 10 10 10 Carbon black 60 60 60 Cobalt salt 0.8 0.8 0.8 Resorcinol Formaldehyde Resin 2.0 2.0 2.0 HMMM 3 - - Stearic acid 0.8 0.8 0.8 Anti-aging 2.0 2.0 2.0 Process oil 4.0 4.0 4.0 Acrylic ester - One 3 Vulcanizing agent 5.0 5.0 5.0 Vulcanization accelerator 0.7 0.7 0.7

<Test Example>

The rubber specimens prepared in Comparative Examples and Examples were measured for rubber initial strength and tensile properties after aging in an oven at 105 ° C. for 3 days according to ASTM-related regulations. The results are summarized in Table 2 below. It is shown.

In addition, after crosslinking the rubber prepared in Comparative Examples and Examples for 35 minutes to a steel cord having a cord structure of 3 * 0.20 + 6 * 0.35HT at 145 ° C for 35 minutes, the degree of rubber adhesion between the steel cord and the adhesive rubber was determined by ASTM-related regulations. The measurement results are shown in Table 2 below.

Table 2. Result of adhesion measurement of rubber and steel cords of Comparative Examples and Examples

Item  Comparative example Example 1 Example 2 Rubber initial strength 227kgf 230kgf 234 kgf Strength after rubber aging (1) 144kgf 152kgf 158kgf T-Test Adhesion Initial 49/90% 57/90% 61/90% Adhesion after aging (2) 41/70% 44/80% 48/90% Adhesion after aging (3) 45/80% 48/80% 52/90%

* Aging (1): 3 days aging in an oven at 105 ℃

* Aging (2): 15 days of aging in an oven at 105 ° C

* Aging (3): 15 days of aging in an oven at 95% relative humidity & 95 ° C

* T-Test adhesive strength initial value, the adhesive strength after aging (2), the comparative values for the adhesive strength after aging (3), the numerical value of Example 1 and Example 2 means the adhesion / rubber adhesion amount (%).

Rubber of Examples 1 and 2 made of the steel cord adhesive rubber composition of the present invention, as shown in Table 2, the result of the test example, compared to the rubber initial strength, strength after aging compared to the rubber of the comparative example made of a conventional steel cord adhesive rubber composition It can be seen that it has excellent tensile properties, and adhesion is also improved, and when applied to a tire, it is possible to improve the long-term running ability of the tire.

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (5)

In the rubber composition for bonding the steel cord, 1 to 5 parts by weight of acrylic ester represented by the following formula (1) based on 100 parts by weight of the raw material rubber; 30 to 80 parts by weight of any one or more fillers selected from the group consisting of titanium dioxide, tungsten, and talc; and a rubber composition for adhesion to steel cords. CH ₂ = CHCOOR ...... (1) In the formula (1), R is a 2-ethylhexyl group. delete delete A rubber comprising the rubber composition of claim 1. A tire comprising a rubber consisting of the rubber composition of claim 1.