JPH1159137A - Decorative tire, coating agent for tire decoration and manufacture of decorative tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative tire capable of satisfying fashion property for a long period, coating agent for tire decoration and a manufacturing method for the decorative tire for which the coating agent for tire decoration is utilized without inviting lowering of moving performance and an increase in cost, as compared with a conventional tire. SOLUTION: This tire is a tire on which colored rubber coating films which are co-vulcanized with a base tire surface in at least a part of the base tire surface is formed and can be manufactured by vulcanizing coating agent for tire decoration made by dissolving rubber component containing 5 to 80 wt.% of non-diene base rubber in all the rubber components; white base reinforcing agent and rubber composition containing vulcanizing agent into organic solvent so that the rubber component may be 3 to 25 wt.% after the coating agent for tire decoration is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire decoration coating agent applied to a rubber surface to decorate a decorative tire and a base tire surface, and a method for manufacturing a decorative tire using the same. The present invention relates to a technique for decorating a low-flat tire, which requires the following.

[0002]

2. Description of the Related Art In recent years, demand for low-flat tires has been increasing. However, it has been found that the purchasers of low-flat tires tend to attach importance to fashion as a tire purchase standard.

As a technique for improving the fashionability of a low-flat tire, for example, there is a method of combining a low-flat tire with a wheel having a larger diameter than usual (hereinafter, referred to as a "large-diameter wheel"). However, the use of a large-diameter wheel leads to an increase in the weight of the entire tire, and such an increase in the weight causes a reduction in the rolling resistance of the tire, that is, a reduction in grip performance due to an increase in the moment of inertia. Originally, low-flat tires are known to have excellent gripping properties, and therefore, a decrease in gripping properties due to the addition of fashionability falls over. Of course, it is not impossible to further improve the grip-up property of the tread portion by improving the rubber composition and the like constituting the tire, and to compensate for the deterioration of the grip property due to the increase in the diameter of the wheel, but for that purpose, The cost of materials is increased, which is uneconomical.

On the other hand, as a method of satisfying fashionability without impairing the original characteristics of a low-flat tire, color coordination between an automobile body and a tire has been considered. That is, there is an increasing demand for colored tires and patterned tires in place of the conventional black tires. To satisfy such demands, spray the pigment-containing paint on the sidewall surface of the tire,
A sticker is provided.

[0005]

However, in the method of attaching a sticker or the like, the sticker is easily peeled off due to the aging of the pressure-sensitive adhesive. Is partially dropped. All of these phenomena lead to deterioration of the appearance, and cause undesirable situations from the viewpoint of fashionability.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a long-lasting fashionable tire without lowering exercise performance and increasing costs as compared with conventional tires. It is an object of the present invention to provide a decorative tire, a coating material for tire decoration, and a method for manufacturing a decorative tire using the coating material, which can satisfy the following.

[0007]

Means for Solving the Problems The decorative tire of the present invention comprises:
A colored rubber coating that is co-vulcanized with the base tire surface is formed on at least a portion of the base tire surface, and the rubber coating includes a non-diene rubber in the total rubber component. It is obtained by vulcanizing a rubber composition containing a rubber component containing 5 to 80% by weight. It is preferable that the sidewall portion of the base tire does not contain an amine-based antioxidant.

The tire decoration coating composition of the present invention comprises a rubber composition containing a non-diene rubber in an amount of 5 to 80% by weight of the total rubber component; a white reinforcing agent; and a vulcanizing agent. The rubber component is dissolved in an organic solvent so as to be 3 to 25% by weight. The method for producing a decorative tire according to the present invention is characterized in that after applying the coating composition for tire decoration of the present invention to the surface of a base tire, the coating composition is vulcanized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the tire decoration coating composition of the present invention will be described. The rubber composition contained in the tire decoration coating composition of the present invention contains a rubber component, a white reinforcing agent, and a vulcanizing agent. The rubber component is a rubber component that can be vulcanized and has weather resistance, and specifically, is a mixture of a diene rubber and a non-diene rubber.

The diene rubber is co-vulcanized with the surface material of the tire (base tire) to which the coating agent is applied in the presence of a vulcanizing agent, and the rubber coating formed on the base tire surface has abrasion resistance. Will be satisfied. That is, the coating film formed by using the coating agent of the present invention not only increases the hardness of the coating film itself by vulcanization, but also bonds with the coating film by co-vulcanization with the rubber constituting the tire. Strength is increased and rub resistance is improved. As the diene rubber, for example, natural rubber (NR), isoprene rubber (IR), styrene butadiene copolymer (SBR), butadiene rubber (BR) and the like are used, and among these, NR is vulcanized at room temperature. It is preferably used because it is possible. BR is preferably used because it is relatively quick in vulcanization and has excellent flex crack resistance. Therefore, as the diene rubber component, N
It is preferable to use a mixture of R and BR.

On the other hand, the non-diene rubber has the weather resistance of the coating film,
Included to improve ozone resistance. An antioxidant usually used for imparting ozone resistance and the like cannot be contained because it causes discoloration of the coating film, so that the rubber itself must have weather resistance and ozone resistance. Because. Further, by using a rubber composition containing a non-diene rubber at a fixed ratio in the rubber component, ozone resistance and weather resistance as a coating agent are also improved.
As the non-diene rubber, for example, butyl rubber (II
R), halogenated butyl rubber (X-IIR), ethylene-propylene copolymer rubber (EPM), ethylene-propylene diene terpolymer rubber (EPDM) and the like.

[0012] The content ratio of the non-diene rubber in the rubber component is 5% by weight or more, preferably 15% by weight or more.
% By weight, preferably 55% by weight or less. If the content of the non-diene rubber is less than 5% by weight, the ozone resistance and weather resistance of the formed rubber coating film cannot be satisfied. On the other hand, when the content ratio of the non-diene rubber exceeds 80% by weight, the ratio of the diene rubber becomes too small, the vulcanizability is reduced, and the rub resistance is reduced.

The white reinforcing agent is compounded as a reinforcing agent instead of carbon black which is a reinforcing agent usually compounded in rubber. That is, it is for forming a rubber coating film other than black and securing the strength of the coating film.

Examples of the white reinforcing agent used for such a purpose include white clay such as kaolinite, precipitated silica, and calcium carbonate. Of these,
In particular, precipitated silica is preferably used because of its excellent reinforcing effect. The amount of such a white reinforcing agent in the rubber composition is preferably 8 parts by weight, particularly 15 parts by weight or more, and more preferably 70 parts by weight, especially 50 parts by weight or less, based on 100 parts by weight of the rubber component. Preferably, there is. If the amount is less than 8 parts by weight, the reinforcing effect is too small and the rub resistance is not satisfactory. On the other hand, when the amount exceeds 70 parts by weight, the white reinforcing agent insoluble in the organic solvent tends to precipitate in the coating agent, which lowers the coating workability of the coating agent and further reduces the uniformity of the coating film. This leads to a decrease in

As the vulcanizing agent, sulfur or a compound capable of supplying sulfur (for example, VULNOC manufactured by Ouchi Shinko Chemical Co., Ltd.)
R) is used. The amount of the vulcanizing agent in the rubber composition is 0.05 parts by weight, particularly 0.2 parts by weight or more, and 5.0 parts by weight, particularly 3.0 parts by weight or less, per 100 parts by weight of the rubber component. Is appropriately selected according to the content of the diene rubber in the total rubber component. If the sulfur content is less than 0.05 parts by weight, the vulcanization becomes insufficient and the strength of the coating film and the bonding strength with the base tire material decrease, and the rub resistance cannot be satisfied. On the other hand, if the content exceeds 5.0 parts by weight, the coating film becomes too hard, which causes a decrease in the elasticity of the decorative tire and, consequently, a decrease in the performance such as cushioning and rolling resistance. Also, the natural vulcanization increases the viscosity of the coating agent and deteriorates coating workability. It is preferable that the rubber composition used in the tire decoration coating composition of the present invention further contains a fluorescent whitening agent, a silane coupling agent, and a vulcanization accelerator.

The fluorescent whitening agent is preferably blended to make the color of the rubber coating film formed more beautiful. Examples of the fluorescent whitening agent include titanium oxide, of which titanium oxide is preferably used. The amount of titanium oxide in the rubber composition is not particularly limited, but is preferably 60 parts by weight or less based on 100 parts by weight of the rubber component. If the amount exceeds 60 parts by weight, the whitening effect does not change, while fluorescent whitening agents such as titanium oxide are expensive and disadvantageous in cost.

The silane coupling agent is preferably compounded to increase the reinforcing effect and to prevent precipitation of the white reinforcing agent. That is, the silane coupling agent bonds with the white reinforcing agent and also with the polymer (rubber component) due to its chemical structure, so that the bonding between the white reinforcing agent and the rubber component is performed via the silane coupling agent. Can be strong. This is because the dispersibility of the white reinforcing agent in the coating agent is improved, the solution stability as the coating agent is increased, and the coating workability and the uniformity of the coating film can be improved. Also, when forming the coating film, the bond between the base tire and the coating film can be strengthened via the silane coupling agent, and the rub resistance is improved.

Examples of the silane coupling agent include bis (triethoxysilylpropyl) tetrasulfide (for example, Si96 manufactured by Degussa, KBE8 manufactured by Shin-Etsu Chemical Co., Ltd.)
46, OSI Specialty A-1289, A-1
89 etc.) are preferably used. The silane coupling agent is not limited to one type, and a plurality of types of silane coupling agents having a thiol-based, amine-based, or halogen-based functional group may be mixed and used. Although the amount of the silane coupling agent depends on the amount of the white reinforcing agent, in order to sufficiently satisfy the stability as a coating agent, it is added in an amount of 1.0 part by weight or more per 100 parts by weight of the white reinforcing agent. Is preferred.
The vulcanization accelerator is blended to increase the vulcanization rate. The type is not particularly limited, and thiazole, carbamate, thiuram and the like can be used.

The following compounds may be further added to the rubber composition constituting the coating composition of the present invention, if necessary. When the rubber coating film to be formed is other than white, various pigments can be blended according to the color of the coating film. For example, as a red pigment, epsilon red LB-06
Ultramarine No. 5 as blue pigment 1500, Epsilon Blue LB-502, LB-5T015, Blue PR-5
19, cyanian blue BSH; Psilo yellow LB-305, LB-310, 3GR-M as a yellow pigment; Epsilon green LB-404 as a green pigment; Epsilon brown LB-9606A as a brown pigment.

When these color pigments are blended,
Carbon black may be blended as long as the color is not impaired. In particular, in the case of a dark color, the effect of color due to the blending of carbon black is small, but carbon black is excellent as a reinforcing agent. When carbon black is compounded, the amount of the carbon black is 10%.
About 3 to 10 parts by weight per 0 parts by weight is preferred.

In addition to the above compounds, fillers usually compounded as rubber materials, specifically, zinc oxide, stearic acid,
A wax, a process modifier (such as a resin) and the like can be blended. In particular, since zinc oxide contributes to the improvement of the hardness of the rubber coating, it may be added when the mixing ratio of the non-diene rubber in the rubber component is large and the increase in hardness of the rubber coating due to vulcanization is small. preferable.

The coating composition for tire decoration of the present invention is obtained by dissolving a rubber composition prepared by mixing and uniformly kneading the above substances in an organic solvent and having a rubber component concentration of 2 in the coating composition. It is a rubber solution of not less than 3% by weight, especially not more than 30% by weight, especially not more than 25% by weight. If the concentration of the rubber component is too low, a uniform coating film cannot be obtained. If it exceeds 30% by weight, a viscous solution is formed, making the coating operation difficult, and dissolving in an organic solvent. This is because an inorganic compounding agent that is difficult to be precipitated is likely to precipitate.

As the organic solvent, benzene, toluene,
Aromatic solvents such as xylene and other petroleum solvents are used. Since the rubber composition is easily dissolved in an aromatic solvent, the rubber composition may be first dissolved in an aromatic solvent and then diluted with a naphtha solvent to a predetermined concentration. The petroleum solvent evaporates in a short time after coating, so it dries quickly,
This is because the rubber component in the coating agent easily penetrates into the base tire.

Next, a method for manufacturing the decorative tire of the present invention will be described. The method for producing a decorative tire according to the present invention is characterized in that the tire decorative coating material of the present invention having the above-described structure is applied to a base tire surface, and then vulcanized, thereby coloring the base tire surface (including white). This is a method of forming a coating film. The portion to which the coating agent is applied is a portion where a rubber coating film is to be formed, and is appropriately selected depending on the design of the tire to be manufactured, such as the entire surface of the base tire or the entire or partial sidewall portion. Vulcanization conditions may be appropriately selected according to the composition of the coating agent.

Next, the decorative tire of the present invention will be described. The decorative tire of the present invention may be manufactured by the manufacturing method of the present invention, or may be manufactured by another manufacturing method.
In short, it is sufficient that a colored rubber coating film co-vulcanized with the surface of the base tire is formed on at least a part of the surface of the base tire.

Although the type of the base tire used in the present invention is not particularly limited, a low-flat tire having a high demand for fashionability, particularly a demand for fashionability on a color surface, is mainly used. The rubber material constituting the base tire is not particularly limited, but a tread portion, a sidewall portion,
It is preferable that the rubber material constituting at least the portion of the shoulder portion where the rubber coating is formed does not contain a substance that causes contamination of the rubber coating. Specifically, an amine-based antioxidant (for example, 6PPD, I
It is preferable not to include PPD). This is because the amine antioxidant migrates to the rubber coating and causes discoloration of the coating, and the white or colorful rubber coating produced to improve the fashionability is discolored and deteriorates the appearance. .

The rubber coating may be made of rubber colored (including white) in addition to black and co-vulcanized with the base tire, and preferably has ozone resistance. Specifically, in the rubber composition as the material, a white reinforcing agent is used instead of carbon black as the reinforcing agent, and it is preferable that 5-80% by weight of the total rubber component is a non-diene rubber. . Further, it is preferable that a silane coupling agent is blended in order to enhance the abrasion resistance of the rubber coating film, and that a fluorescent whitening agent (for example, titanium oxide) is blended in order to make coloring more beautiful. preferable. Most preferably, the rubber composition used in the coating agent of the present invention is used as a coating material.

The thickness of the rubber coating is 0.03 mm or more,
Especially 0.05 mm or more, 0.6 mm or less, especially 0.5
mm or less. Therefore, when the production method of the present invention is employed, it is preferable that the amount of the coating agent applied is such that a coating film having such a thickness can be formed.

The shape and the like of the coating film are appropriately selected according to the required fashionability. For example, in the case of a colored tire including white, the rubber coating film covers the entire side wall portion, and in the case of a patterned tire, a coating film corresponding to the pattern is formed. Further, the color of the coating film can be variously colored depending on the type of the pigment to be blended in the rubber composition as a material, as well as the white color of the reinforcing agent.

As described above, the decorative tire of the present invention can meet various demands for fashion by changing the shape and color of the rubber coating film in various ways. Is co-vulcanized with the surface of the base tire, so that the aesthetic appearance can be maintained for a long time. Further, since the decorative tire of the present invention has only a thin rubber coating film formed on the surface of the base tire, it does not affect tire performance as in the case of using a large-diameter wheel. It is possible to meet the demand for fashionability at a lower cost than when using it.

[0031]

Embodiments of the present invention will be described below. First, the evaluation method used in the present invention will be described.

[Evaluation Method] A: Coating agent The dispersibility of various compounds and the aging of the coating agent were evaluated. Dispersibility of coating agent After standing for one month from preparation of coating agent, the degree of precipitation was visually observed, and the results were evaluated as follows: ○ (no precipitation), Δ (emulsion state), ×
(Precipitated and the solution and formulation were completely separated).

Time-dependent change of the coating agent The change in the state of the coating agent after the coating agent was allowed to stand at 50 ° C. for 10 days was visually observed and compared with the state immediately after preparation. Changes in the state, ○ (no change), △ (emulsion state),
The evaluation was made in three stages of x (precipitated and completely separated).

B: About Decorative Tire Rub Resistance The prepared decorative tire was mounted on a Nissan laurel, and the speed was set to 10 per hour.
After rubbing the green stone for 2.5 m (equivalent to two rotations of the tire) at km or less, the state of the coating film was visually observed. From the degree of peeling of the coating film, ○ (almost no peeling), Δ (peeling was observed, but there was no significant effect on fashionability), ×
(The peeling was so bad that the appearance was deteriorated).

Ozone resistance Evaluated according to JIS K-6259. That is, cut out the part including the rubber coating of the manufactured decorative tire,
Cut the cut rubber sample in air containing ozone for 30 minutes.
After leaving for a few days, based on the number and size of cracks formed in the coating film, ○ (no cracks were observed with the naked eye), Δ (small cracks were visible with the naked eye), × (confirmed with the naked eye) (There were many possible cracks).

Discoloration resistance The prepared decorative tire was allowed to stand for one month in a place exposed to sunlight, and the coating film was observed. From the degree of discoloration, ○ (no discoloration), Δ (slightly discolored, but little influence on appearance), ×
(Discoloration and deterioration in appearance).

[Preparation of Coating Agent] In the rubber compound shown in Table 1, the rubber component, white reinforcing agent, titanium oxide, blue pigment, silane coupling agent, sulfur and zinc oxide were mixed in the amounts shown in Table 2, A rubber composition was prepared by kneading the mixture so as to be uniform. The amount of zinc oxide is an amount appropriately selected according to the rubber component and the amount of sulfur so that the hardness of the finally formed coating film is substantially the same.

The rubber composition prepared was first dissolved in toluene and then diluted with naphtha so that the final concentration of the rubber component was 10% by weight. 1 to 7 coating compositions were prepared. No. The coating agents according to 2 to 5 and 7 are the coating agents belonging to the examples of the present invention.

As the butadiene rubber, BR1220 (trade name) manufactured by Zeon Corporation, and as the chlorobutyl rubber, chlorobutyl 1066 (trade name) manufactured by Exxon Corp.
As PDM, Explain 502 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and as silica, Ultrasil V manufactured by Degussa Co., Ltd.
N3 (trade name), as titanium oxide, A made by Ishihara Sangyo
-100 (trade name), as a blue pigment, Ultramarine No. 1500, Si69 manufactured by Degussa was used as a silane coupling agent. As the clay, a hard crown clay (a hydrous aluminum silicate, which had a loss on heating of 1.5% or less and a pH of 4.5 to 5.5 as measured according to JIS K 6223) was used. The dispersibility and the change with time of the prepared coating agent were evaluated by the above evaluation methods. Table 2 shows the evaluation results.

[0040]

[Table 1]

[Production of Decorative Tire] As a base tire, a tire (205 / 60R15 91H LM) having a sidewall portion made of a rubber composition A or B shown in Table 3
601 T / L). The No. prepared above was applied to the entire sidewall portion of the base tire. Each of the coating materials Nos. 1 to 7 was uniformly applied and left in an oven at 80 ° C. for one day to obtain white (No. 1, 5) or blue (No. 2 to No. 2).
(4, 6, 7) The decorative tire on which the rubber coating film was formed was produced. The thickness of the rubber coating film in each tire is as shown in Table 2. No. About 1-7 decorative tires,
A sample from which a portion including the rubber coating was cut was immersed in toluene for 24 hours. For the samples Nos. 1 to 5 and 7, the rubber coating did not melt or peel off. That is, it was confirmed that the tire made of the rubber composition containing the vulcanizing agent had the rubber coating film co-vulcanized with the base tire. Therefore, the tires (Nos. 2 to 5, 7) produced by applying the coating agent of the present invention correspond to the decorative tires of the present invention. About the produced decorative tire, rub resistance, ozone resistance, and discoloration resistance were evaluated based on the above evaluation method. Table 2 shows the evaluation results.

[0042]

[Table 2]

[0043]

[Table 3]

[Evaluation] Table 2 shows that In the case of using the decorative tire of Nos. 1 to 5 and 7, that is, a coating composition in which a vulcanizing agent is blended with a rubber composition, the rubber coating film is co-vulcanized with the base tire, so that the rub resistance is satisfied. Was completed. Furthermore, the tires (Nos. 1, 2, 3, and 5) using the coating composition in which the silane coupling agent was blended with the rubber composition were particularly excellent in rub resistance. No. 3-5, 7 decorative tires,
That is, the rubber coating film made of the rubber composition containing the non-diene rubber also satisfied the ozone resistance.

Further, the decorative tires No. 2 differ only in the rubber material other than the base tire. From the results of the discoloration resistances of Nos. 4 and 7, it can be seen that the presence or absence of discoloration of the coating film depends on the presence or absence of a contaminant in the base tire.

In the case where the silane coupling agent was not blended at all (Nos. 4, 6, and 7), the amount of the silane coupling agent was less than 1 part by weight (No. 4).
3) In the case where the blending amount of the silane coupling agent was 1 part by weight or more (Nos. 1, 2, and 5), the stability was improved in the order.

[0047]

According to the decorative tire of the present invention, since a rubber coating film that can satisfy the demand for fashion is co-vulcanized with the base tire, the tire is simply provided with fashion by sticking a sticker or painting. Compared with, fashionability can be maintained for a long time. Further, the decorative tire of the present invention can exhibit the inherent performance as a tire and can be manufactured at a low cost, unlike the decorative method using a large-diameter wheel. Further, by appropriately changing the shape and color of the coating film, a variety of decorative tires can be provided.

The coating composition for tire decoration of the present invention is a coating composition suitable for producing the decorative tire of the present invention, and is excellent in stability over time and coating workability by blending a silane coupling agent. I have. According to the method for manufacturing a decorative tire of the present invention, the decorative tire of the present invention can be easily manufactured.

Claims (4)

[Claims] 1. A colored rubber coating film co-vulcanized with the base tire surface is formed on at least a part of the base tire surface, and the rubber coating film is a non-diene rubber. A rubber composition obtained by vulcanizing a rubber composition containing a rubber component containing 5 to 80% by weight of the total rubber component. 2. The decorative tire according to claim 1, wherein the sidewall portion of the base tire does not contain an amine-based antioxidant. 3. The non-diene rubber is used in an amount of 5 to 80 in the total rubber component.
A tire comprising: a rubber composition containing a rubber component containing a rubber component containing 1% by weight; a white reinforcing agent; and a vulcanizing agent dissolved in an organic solvent such that the rubber component becomes 3 to 25% by weight. Decorative coating agent. 4. A method for producing a decorative tire, comprising applying the coating composition for tire decoration according to claim 3 to a surface of a base tire and vulcanizing the coating composition.