KR20020080781A - Rubber composition improved cohesive - Google Patents

Abstract

PURPOSE: Provided is a rubber composition capable of maintaining the viscosity and the adhesiveness of rubber at more than level equivalent to those of rubber composition using the existing coumarone indene resin. CONSTITUTION: The rubber composition comprises 1-5 phr of petroleum resin as an adhesive with respect to 100 phr of rubber material, in order to improve adhesiveness. The rubber material is selected from a natural rubber, a styrene butadiene rubber, a butadiene rubber, an acrylonitrile butadiene rubber, or a mixture thereof. The petroleum resin represented by a structure of formula 1(wherein n is 4-15) is an aliphatic petroleum resin which is obtained by cationically polymerizing a fraction of oil obtained by naphtha fractionation with boiling point of 20-80 deg.C, by using aluminum chloride(AlCl3) as a catalyst.

Description

Rubber composition improved cohesive

The present invention relates to a rubber composition having improved adhesion, and more particularly, to a rubber composition having improved viscosity and adhesion by adding petroleum resin to the rubber composition as an adhesive.

In the case of synthetic rubber, the adhesive strength is lower than that of natural rubber, and when synthetic rubber is used as a raw material rubber, it contributes to the improvement of rubber properties by increasing the adhesive strength and filler dispersion performance by adding an adhesive in the molding process.

Conventional pressure-sensitive adhesives used in rubber compositions include natural resins and synthetic resins. Alkali phenol resins of synthetic resins and low price coumarone indene resins, which are coal tars, are used, but coumarone indene resins mainly composed of coke gas are used. Currently, the supply and demand of raw materials is unstable due to the specification of the coal industry, and the number of producers is gradually decreasing. Therefore, replacement of adhesives with the same physical properties and the same price is required.

As described above, the present invention uses petroleum resin as a pressure-sensitive adhesive to replace coal tar-based coumarone indene resin with similar properties such as material, color, heat resistance, and synthetic rubber. As a result, an object of the present invention is to provide a rubber composition capable of maintaining the viscosity and adhesive strength of the rubber at an equivalent level or higher than that of the conventional rubber composition using the coumarone indene resin.

Rubber composition with improved adhesion of the present invention is a rubber composition known in the art, using natural rubber, styrene butadiene rubber, butadiene rubber, acrylonitrile butadiene rubber alone as the raw material rubber, or the adhesive for 100 phr mixed rubber As petroleum resin, characterized in that it comprises 1 to 5 phr.

The mixing ratio of the natural rubber, styrene butadiene rubber, butadiene rubber and acrylonitrile butadiene rubber used as the raw material rubber is not constant, but may be used by adjusting the mixing ratio according to the rubber product of interest.

The petroleum resin used as an adhesive in the present invention has a structural formula represented by the following formula (1), and uses an aliphatic petroleum resin obtained by cationic polymerization of an oil having a boiling point of 20 to 80 ° C. with a catalyst of aluminum chloride (AlCl ₃ ) in naphtha cracked oil. .

Expression (1)

In said formula (1), n is 4-15.

In addition, the petroleum resin that can be used as a pressure-sensitive adhesive in the present invention may be used in addition to the aliphatic petroleum resin aromatic petroleum resin, such aromatic petroleum resin has a structural formula of the following formula (2) styrene (styrene), vinyl toluene in naphtha decomposition oil (vinyl toluene) or indenes (Indene) is an aromatic resin obtained by cationic polymerization of a boiling point of 145 ~ 210 ℃ fraction with a catalyst of aluminum chloride (AlCl ₃ ) or fluorine boron (BF ₃ ).

Expression (2)

In Formula (2), n is 6 to 20, and R is styrene, vinyl toluene or indene.

Meanwhile, the copolymer obtained by copolymerizing the aliphatic petroleum resin and the aromatic petroleum resin may be used as a pressure-sensitive adhesive after preparing a copolymer by mixing C5 oil and C9 oil.

In the present invention, the petroleum resin used as the adhesive is less than 1 phr with respect to 100 phr of the raw material rubber, the viscosity of the rubber is increased, the adhesive strength is not good, when used more than 5 phr, the hardness of the rubber is lowered, wear performance is reduced, When the rubber composition is used for tread of tires, the stability of steering is reduced, and the performance of the tack is so good that it is impossible to reshape during molding process, so it is difficult to change the shape of the semi-finished product. It is preferable to include 1 to 5 phr for 100 phr.

Hereinafter, the present invention will be described by the following comparative examples, examples and test examples. However, these are only for illustrating the present invention, and the present invention is not limited thereto.

<Example 1>

As shown in Table 1 below, with respect to 100 phr of natural rubber as a raw material rubber, a weight average molecular weight of 7190, a number average molecular weight of 2010, and an aliphatic petroleum resin of 1.5 phr, which can be represented by the following structural formula (1), are known to tire rubber compositions 50 phr of carbon black, 6 phr of active agent, 3.0 phr of sulfur, and 1.5 phr of accelerator were added to a Banbury mixer, mixed, and cured at 160 ° C. for 30 minutes to prepare a rubber specimen.

Expression (1)

<Example 2>

Except using 3.0 phr of aliphatic petroleum resin, the same composition and composition as in Example 1 were placed in a Banbury mixer, mixed, and cured at 160 ° C. for 30 minutes to prepare a rubber specimen.

<Example 3>

Except for using 5.0 phr of aliphatic petroleum resin, the same composition and composition as in Example 1 were placed in a Banbury mixer, mixed, and cured at 160 ° C. for 30 minutes to prepare a rubber specimen.

Comparative Example 1

Except using 3.0 phr of coumarone indene resin instead of petroleum resin as a pressure-sensitive adhesive was prepared in the same composition and composition as in Example 1 in a Banbury mixer and mixed for 30 minutes at 160 ℃ to prepare a rubber specimen.

<Example 4>

As shown in Table 1 below, 2.0 phr of the same aliphatic petroleum resin as that of Example 1 was used as a pressure-sensitive adhesive for 100 phr of styrene butadiene rubber as a raw material rubber, 70 phr of carbon black used in a known tire rubber composition, 10 phr of active agent, and 5.0 phr of sulfur. , 1.5 phr of accelerator was added to a Banbury mixer, mixed and cured at 160 ° C. for 30 minutes to prepare a rubber specimen.

Example 5

Except using 4.0 phr of aliphatic petroleum resin, the same composition and composition as in Example 4 were placed in a Banbury mixer, mixed, and then vulcanized at 160 ° C. for 30 minutes to prepare a rubber specimen.

<Example 6>

Except for using 6.0 phr aliphatic petroleum resin, the same composition and composition as in Example 4 were put in a Banbury mixer, mixed and vulcanized at 160 ° C. for 30 minutes to prepare a rubber specimen.

Comparative Example 2

Except for using the cougaron indene resin 4.0 phr instead of petroleum resin as the pressure-sensitive adhesive was prepared in the same composition and composition as in Example 4 in a Banbury mixer and mixed for 15 minutes at 160 ℃ to prepare a rubber specimen.

Table 1. Rubber Compositions of Comparative Examples and Examples (Unit: phr)

Item Comparative Example 1 1 to implementation Example 2 Example 3 Comparative Example 2 Example 4 Example 5 Example 6 Raw material rubber 100 100 100 100 100 100 100 100 Carbon black 50 50 50 50 70 70 70 70 Active agent 6 6 6 6 10 10 10 10 adhesive* 3.0 - - - 4.0 - - - adhesive** - 1.5 3.0 5.0 - 2.0 4.0 6.0 sulfur 3.0 3.0 3.0 3.0 5.0 5.0 5.0 5.0 accelerant 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

* Indicates oil balance

** indicates coumarone indene resin

<Test Example>

The rubber specimens prepared by the method of Comparative Examples and Examples were measured by rheometer, Mooney viscosity, tensile property, and adhesive force according to ASTM-related regulations, and the results are shown in Table 2 below.

Table 2. Measurement results of the rubber specimens of Comparative Examples and Examples

Item Comparative Example 1 Example 1 Example 2 Example 3 Comparative Example 2 Example 4 Example 5 Example 6 Rheometer T40 13 11 13 13 14 12 14 13 T90 18 19 17 17 32 33 33 32 Torque 44 42 44 43 72 70 71 70 Mooney viscosity Viscosity 63 62 59 55 53 52 49 45 Scorch Time 25 25 27 28 27 27 28 28 Tensile Properties Hardness 63 63 61 59 86 86 84 80 300% modulus 140 142 142 142 - - - - The tensile strength 277 283 283 283 168 169 175 176 Elongation 505 513 513 513 151 155 162 170 adhesiveness Early 0.3 0.2 0.4 0.7 4.0 3.8 4.5 6.4 1 day aging * 1.0 0.9 1.4 1.6 6.0 5.7 7.2 9.7 3-day aging 1.0 1.0 1.5 1.9 9.5 8.9 10.2 12.1

* Aging temperature is 160 ℃

As shown in Table 2, the rubber tensile properties of the rubber composition using the petroleum resin of the present invention as a pressure-sensitive adhesive maintained at least the same level as the rubber tensile properties of the rubber composition using a conventional Kumaron indene resin as a pressure-sensitive adhesive. It can be seen that the improvement.

Claims (4)

Known rubber compositions comprising 1 to 5 phr of petroleum resin as an adhesive with respect to 100 phr of raw rubber in order to improve adhesion. The rubber composition according to claim 1, wherein the raw material rubber is a natural rubber, a styrene butadiene rubber, a butadiene rubber, an acrylonitrile butadiene rubber, or a mixed rubber thereof. The petroleum resin is an aliphatic petroleum resin having a structural formula of the following formula (1), wherein the naphtha decomposition oil is cationicly polymerized with an oil having a boiling point of 20 to 80 ° C. with a catalyst of aluminum chloride (AlCl ₃ ). Rubber composition Expression (1) In said formula (1), n is 4-15. The petroleum resin of claim 1, wherein the petroleum resin has a structural formula of Formula (2) below and includes styrene, vinyl toluene or indene in naphtha cracked oil, and the boiling point of 145-210 ° C. is chlorinated. Rubber composition characterized in that the aromatic resin is cationic polymerization of a catalyst of aluminum (AlCl ₃ ) or fluorine boron (BF ₃ ) Expression (2) In Formula (2), n is 6 to 20, and R is styrene, vinyl toluene or indene.