KR100731668B1 - Cement Composition for Tread Junction of Tire - Google Patents

Abstract

The present invention relates to a cement composition for tire tread joining, wherein the cement composition is used to increase the vulcanization density of the tread joint after vulcanization to enhance adhesion, thereby improving the phenomenon that the tread joint of the tire is opened by high speed traveling and high speed cornering. For the purpose of

To this end, the present invention relates to a cement composition for tread joining of tires having the same net rubber composition as that of the high-speed racing tread comprising raw rubber, carbon black, process oil, sulfur, vulcanization accelerator and other rubber compounding agents. And carbon black having a CTAB surface area of 130 to 260 m 2 / g as the carbon black and 85 to 150 ml / 100 g of 24M4 DBP oil absorption, and containing 60 to 200 parts by weight with respect to 100 parts by weight of the raw material rubber. Here, it is preferable that the total content of the sulfur and the vulcanization accelerator to be added is 6.0 to 9.0 parts by weight based on 100 parts by weight of the raw material rubber.

Tires, treads, joints, gaps, high speed travel, racing, cement compositions, carbon black, CTAB, surface area, oil absorption, sulfur, vulcanization accelerators

Description

Cement Composition for Tread Junction of Tire

The present invention relates to a cement composition for tire tread bonding, and more particularly, to increase the vulcanization density of the tread joint after vulcanization by using a cement composition to improve the phenomenon of the tread joint of the tire being opened by high speed traveling and high speed cornering. It relates to a cement composition for tread bonding of a tire that is made to strengthen the adhesive force.

In general, when driving a car, the tread joint of the tire is subject to a lot of external stress due to the continuous rotation of the tire. In particular, tires used under severe conditions such as high-speed cornering, such as automobile racing, have a large phenomenon in the tread joints of tires caused by external stress during high-speed driving, and this phenomenon reduces steering stability and durability in high-speed driving. It acts as a fatal cause.

If the tread joint is opened while driving, the vibration of the tire is severe, and the adjustment stability is drastically lowered. In addition, the tires temporarily fall off the ground, resulting in a substantial loss of tire inherent performance, and even worse, the tread may be separated from the tires.

In the past, the gap of the tread joint did not appear to be lower than the limit speed of the vehicle, but in recent years, the limit speed of the tire is increased, and as the series of tires is lowered, the stress on the tread portion of the tire is increased. In particular, in the case of high-speed racing tires, not only the limit speed is high, but also the high speed cornering causes the gap of the tread joint to occur more frequently. This phenomenon is caused by the special structure of the tread used in addition to the above-mentioned causes. It can also be found in the composition.

On the other hand, the vulcanization process in the tire manufacturing process usually contains sulfur and other vulcanization accelerators in the raw material rubber to induce a strong bonding force between the rubber and the filler by heating, pressurizing and other methods, so that the excellent thermal stability of the rubber after vulcanization, It is an important manufacturing process for improving elasticity and tensile strength. In addition, this vulcanization process consists of holding for a suitable time under a specific temperature and pressure.

However, when the tread joint is subjected to the vulcanization process under the same conditions, it has a relatively weak bonding force compared to other parts of the tread, which causes a phenomenon that the bonding force is easily lost due to dynamic fatigue during driving.

In general, in the case of high-speed racing car tires, a slick type tire without a tire pattern is used to design the maximum frictional force to maximize the grip performance and to provide the best grip performance. Of course, they use a lot of carbon and process oils compared to regular tires.

Therefore, the high speed race car tires are frequently caused to open the tread joint compared to the general tires due to such a complex cause.

In the related art, the following methods have been used to improve the spreading phenomenon of the tread joint as described above.

1) Tire tread joining method

Unlike general tire tread joining methods, high-speed car racing tires are designed to improve the spreading of the joints by maintaining a relatively large joint area by varying the angle of the tread joint. However, not only does this improvement not completely improve the phenomena of the tread joints, but also causes disadvantages such as uneven joining of the tires when forming a tire due to maintaining a relatively large joint area.

In addition, when molding a part of the tread portion by using a hot knife to form a high temperature of the adhesive surface during molding, the bonding strength of the interface is somewhat improved, but the interface is irregular by the use of a knife. In particular, if the knife is often used, foreign matter may be attached to the knife, and when the foreign material acts on the cutting surface, the bonding force may be rather deteriorated.

2) How to treat the tread joints separately

A method for applying a chemical treated separately to a tread joint is disclosed in Korean Patent Laid-Open Publication No. 2003-0042890. According to this publication, a dissolving solution in which a vulcanization accelerator is dissolved in a solvent is applied to a tread joint to improve adhesion after vulcanization. It is described as maximizing. However, if such a method is used, the vulcanization accelerator is very difficult to dissolve in the solvent, so that the vulcanization accelerator is present in a precipitated state, and thus there is a problem in that a lot of variation occurs during application, making it difficult to work uniformly between products.

3) Application method of rubber cement

In order to overcome the limitations of the methods 1) and 2), a method of applying cement to the tread joint to improve the adhesive force in the unvulcanized state and the adhesive force of the tread joint after vulcanization has been conventionally used. However, this method of cement application also did not achieve a complete improvement in adhesion due to the differences in the composition of the cement and the tread for treadmills, and in some cases the cement acted as a foreign material, resulting in a decrease in the adhesion of the joint. There was a downside.

Specifically, in the case of natural rubber (NR) cement, which has been conventionally used, it is effective in terms of adhesion in the unvulcanized state, but the dynamic viscoelastic characteristics between the rubber for synthetic rubber racing and the natural rubber cement rubber after vulcanization As a result, a phase separation phenomenon occurs and adversely affects the adhesion of the tread joint.

In addition, styrene-butadiene rubber (SBR) cement, which has been used in the past, also has a different rubber composition from tire tread rubber for high-speed racing cars, and has a great effect on the dynamic adhesion after vulcanization due to the difference in physical properties and the weak vulcanization system. I haven't seen it.

On the other hand, Japanese Patent Application Laid-Open No. 01-288434 discloses a rubber composition of a gluing kit which can be used for adhesion of vulcanized rubber and vulcanized rubber, in particular, re-adhesive bonding of tires, tire bonding by tread joining, or tire and tube repair. It is based on the use of a vulcanization accelerator in a large amount (0.1-15 parts by weight). However, since the conventional technology is based on the rubber composition of the natural rubber system, even if a large amount of vulcanization accelerator is used, the vulcanization accelerator after vulcanization may have a different phase behavior at the interface, and thus may adversely affect the improvement of the bonding force of the tread part during driving. Thus, the prior art is also not suitable for application to general tires and especially high-speed racing car tires under harsh driving and road conditions.

Furthermore, Korean Patent Laid-Open Publication No. 2004-0000890 discloses a cement composition having the same pure rubber composition as the tread rubber composition of a high-speed racing tire but containing 5 to 10 parts by weight of a vulcanization accelerator, but such a composition may be used. In case of molding, there was a problem that the adhesive strength is lowered.

Therefore, in order to solve the problems described above, the present inventors are trying to maximize the bonding force after vulcanization by increasing the vulcanization density of the tread joint, and based on the high-speed racing tread rubber composition, the particle size of carbon black and As a result of using an appropriate amount of sulfur and vulcanization accelerator, it has been found that the tread joint gap that may occur during driving can be improved without changing the physical properties of other parts, thereby completing the present invention.

Accordingly, an object of the present invention is to increase the vulcanization density of the tread joint after vulcanization while strengthening the adhesive force by increasing the vulcanization density of the tread joint after vulcanization, and the tread joint of the tire due to high speed running and high speed cornering. It is to provide a cement composition for tread bonding of a tire that can be effectively prevented.

The cement composition for tire tread joining of the present invention for achieving the above object is in the same order as the rubber composition of the high speed racing tread comprising raw rubber, carbon black, process oil, sulfur, vulcanization accelerator and other rubber compounding agents. In the cement composition for tread joining of a tire having a rubber composition, carbon black having a CTAB surface area of 130 to 260 m 2 / g and a 24 M4 DBP oil absorption of 85 to 150 ml / 100 g is 60 to 100 parts by weight of the raw material rubber as the carbon black. It is characterized by including -200 parts by weight.

Moreover, as said vulcanization accelerator, the vulcanization accelerator (1) which is either alkylphenol disulfide or alkylphenol formaldehyde resin, guanidine system, sulfenamide system, thiazole system, aldehyde ammonia system, thiuram system, dithio carbamate system, And a mixture of one or more vulcanization accelerators (2) selected from the group consisting of xanthates in an appropriate ratio.

In particular, in the present invention, the total content of the sulfur and the vulcanization accelerator may be 6.0 to 9.0 parts by weight based on 100 parts by weight of the raw material rubber.

EMBODIMENT OF THE INVENTION Below, this invention is demonstrated in detail.

The present invention is based on the rubber composition of the high-speed racing tread, while using an appropriate amount of carbon black having a small particle size. That is, the cement composition for tread joining according to the present invention has the same pure rubber composition as the rubber composition of the high-speed racing tread including raw rubber, carbon black, process oil, sulfur, vulcanization accelerator and other rubber compounding agents. The carbon black was obtained by adding 60 to 200 parts by weight of carbon black having a CTAB surface area of 130 to 260 m 2 / g and a 24M4 DBP oil absorption of 85 to 150 ml / 100 g based on 100 parts by weight of the raw material rubber. The process oil is used 50 to 200 parts by weight based on 100 parts by weight of the raw material rubber.

Here, the reason for using the small particle size of the carbon black is to maximize the bonding force limited to the tread joint interface. If the carbon black has a large particle size, it causes a weakening of the bonding force. Therefore, it is preferable to use a small particle size as described above.

In addition, the vulcanization accelerator is added to the tread joint interface when forming the tire to maximize the bonding force as described above, the vulcanization accelerator (Alkyphenol Disulfide or any one of the alkylphenol formaldehyde resin (Alkyphenol Formaldehyde Resin) 1) and; Guanidine, Sulfenamide, Thiazole, Aldehyde Ammonia, Thiuram, Dithiocarbamate, and Xanthate At least one vulcanization accelerator (2) selected from the group consisting of; Mixtures are used, but are not necessarily limited thereto.

Such vulcanization accelerators are preferably used with sulfur so that the total content thereof is 6 to 9 parts by weight based on 100 parts by weight of the raw material rubber. If the total content of sulfur and the vulcanization accelerator is less than 6 parts by weight, the vulcanization density at the interface after the cement solution is not sufficient, and if the total content is more than 9 parts by weight, when processing and dispersing in blending in the rubber composition There is a problem that a defect occurs and the physical properties of the interface is too high after tire production.

Moreover, as a raw material rubber used in the rubber composition of a high speed racing tire, natural rubber, styrene-butadiene rubber, etc. are used as mentioned above. Therefore, the cement composition of the present invention is prepared by dissolving these in an organic solvent, including the above-described raw material rubber, including an anti-aging agent, process oil, pressure-sensitive adhesive, sulfur, vulcanization accelerator, and the like, which are conventional compounding agents.

At this time, a cyclohexane-based solvent is used as the organic solvent, but the type thereof is not particularly limited since it does not affect the effect of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example  1-3 and Comparative example  1 to 3

To prepare Examples 1 to 3 with a formulation composition as shown in Table 1 below, the solids content of 5%, 10%, 10%, respectively, the total content of sulfur and vulcanization accelerator 7 parts by weight Cement compositions were prepared.

In addition, to prepare a Comparative Example 1 to Comparative Example 3 with a compounding agent composition as shown in Table 1, all the solid content of 10%, and the total content of sulfur and vulcanization accelerator to 3.1 parts by weight to prepare a cement composition It was.

division Example 1 Example 2 Example 3 Comparative Example 1 (NR system) Comparative Example 2 (SBR System) Comparative Example 3 Natural rubber - - - 100 - - SBR (1) - - - - 100 - SBR (2) 137.5 137.5 137.5 - - 137.5 Carbon black (1) - - - 50 65 90 Carbon black (2) 120 120 120 - - - Process oil 60 60 60 4 10 40 adhesive 10 10 10 20 50 20 ZnO / Stearic Acid 4/2 4/2 4/2 5/2 3/1 4/2 brimstone 4.0 4.0 2.0 2.0 2.0 2.0 Vulcanization Accelerators (1) 3.0 3.0 5.0 1.7 1.7 1.7 Vulcanization Accelerators (2) 3.0 3.0 5.0 - - - Vulcanization Promoter (3) - - - 0.5 0.5 0.5 Solid content 5% 10% 10% 10% 10% 10% Sulfur + (1/2 Vulcanization Accelerator) ^{# 1)} 7 7 7 3.1 3.1 3.1 -NR: Natural rubber-SBR (1): Emulsion-polymerized styrene-butadiene copolymer rubber with styrene bond amount 23.5% by weight-SBR (2): Emulsion-polymerized styrene-butadiene copolymer rubber with styrene bond amount 40% by weight This 37.5 parts by weight is incorporated. Carbon black (1): CTAB surface area is 100 m 2 / g and 24M4 DBP oil absorption is 80ml / 100g. -Carbon black (2): CTAB surface area is 230 m2 / g and 24M4 DBP oil absorption is 95ml / 100g-Process oil: Aromatic oil-Pressure sensitive adhesive: koresin-Sulfur: Sulfur equivalent to conventional rubber vulcanizing agent-Vulcanization accelerator (1): sulfenamide accelerator-vulcanization accelerator (2): alkylphenol disulfide or alkylphenol formaldehyde resin-vulcanization accelerator (3): amine accelerator ^{# 1} : sulfur + (1/2 vulcanization accelerator) is sulfur It means a weight part + (vulcanization accelerator (1) weight part + a vulcanization accelerator (2) weight part) / 2.

Here, Comparative Example 1 is a cement composition used in a general tread joint, Comparative Example 2 is a cement composition used in the SBR-based tread joint, Comparative Example 3 is a conventional high-speed tire tread rubber composition.

Each cement composition thus prepared was applied to a joint in an unvulcanized state prepared using a tread rubber composition of a normal high speed tire, and the samples were bonded to each other in a manner similar to that of tire tread bonding. The final test sample was prepared by quenching for a minute.

In order to confirm the adhesion of the finally prepared sample, the adhesion test of the adhesion interface and the test after adhesion to 1 day standing at 105 ℃ temperature, the adhesion was tested, the results are shown in Table 2.

 division  Example 1  Example 2  Example 3  Comparative Example 1  Comparative Example 2  Comparative Example 3 Adhesion Before aging 41.5 39.8 38.7 19.5 22.4 26.7 After aging 40.7 37.5 37.5 15.9 18.3 20.8

According to the results of Table 1, Examples 1 to 3 prepared from the cement composition for tread bonding of the high-speed racing tire of the present invention was found to have superior adhesive strength compared to Comparative Examples 1 to 3, the interface of the adhesive surface Separation aspect It was also shown that the rubber itself was not delaminated, but the bonding force of the tread joint was excellent. In particular, in the case of Comparative Example 3, the adhesive strength showed a great difference before and after aging, but Examples 1 to 3 of the present invention can be seen that there is not much difference in the adhesive strength before or after aging was able to confirm a marked improvement effect .

As described above, according to the present invention, as in the composition used in the tread rubber composition of a general high speed racing tire, 100 parts by weight of raw material rubber, 60 to 200 parts by weight of carbon black, 50 to 200 parts by weight of process oil, pressure-sensitive adhesive , Sulfur, a vulcanization accelerator, and other rubber compounding agents, wherein the carbon black is carbon black having a CTAB surface area of 130 to 260 m 2 / g and a 24 M4 DBP oil absorption of 85 to 150 ml / 100 g. And by using a composition in which the total content of the vulcanization accelerator is 60 to 200 parts by weight based on 100 parts by weight of the raw material rubber, the vulcanization density of the tread joint after vulcanization is increased, thereby enhancing the adhesive force, and thus, the tire is driven by It is possible to effectively prevent the tread joint from opening.

Claims (3)

In the cement composition for tread joining of tires having the same net rubber composition as the rubber composition of the high-speed race tread comprising raw rubber, carbon black, process oil, sulfur, vulcanization accelerator and other rubber compounding agents, the CTAB is used as the carbon black. A cement composition for tread joining tires, comprising carbon black having a surface area of 130 to 260 m 2 / g and a 24 M4 DBP oil absorption of 85 to 150 ml / 100 g, based on 100 parts by weight of the raw material rubber. The method of claim 1, The vulcanization accelerators are vulcanization accelerators (1) which are either alkylphenol disulfide or alkylphenol formaldehyde resins, guanidine-based, sulfenamide-based, thiazole-based, aldehyde ammonia-based, thiuram-based, dithiocarbamate-based, and A cement composition for tread joining a tire, characterized by mixing at least one vulcanization accelerator (2) selected from the group consisting of xanthate. The method according to claim 1 or 2, The total content of the sulfur and the vulcanization accelerator is 6.0 to 9.0 parts by weight based on 100 parts by weight of the raw material rubber, characterized in that the cement composition for tread joining tires.