JP2000169762A - Film-forming coating agent and tire coated therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating agent capable of forming a protecting film removable by washing with water, excellent in strength and flexibility and having a uniform and sufficient thickness thereby improving antifouling property and resistance to external damages of a tire by incorporating an inorganic thickening agent containing silicon dioxide and aluminum oxide into a solution obtained by dissolving a vinylic resin or a polyamide-based resin in a solvent. SOLUTION: In 100 pts. by wt. of a solvent, 10-20 pts. by wt. of a film- forming agent comprising at least one resin selected from among vinylic resins and polyamide-based resins are dissolved to give a solution. Into 100 pts. (in terms of the total solid) by wt. of this solution, 5-15 pts. by wt. of an inorganic thickening agent containing silicon dioxide and aluminum oxide are incorporated to give a film-forming coating agent having a viscosity of 1-10,000 cP. This film-forming coating agent is coated on the surface of a white rubber 2 buried in the sidewall portion 5 outside the carcass portion 7 extending from a tread portion 4 via a sidewall portion 5 to a bead portion 6 to form a protecting film 3 so that the thickness is 5-100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can form a protective film which can be washed and removed by being applied to the surface of a white rubber used for, for example, a sidewall portion of a tire. The present invention relates to a film-forming coating agent which can be effectively prevented from being contaminated by, for example, and a tire to which the coating agent is applied.

[0002]

2. Description of the Related Art In recent years,
There is a strong demand for fashionability of tires. In particular, in tires for four-wheel drive vehicles and the like, it is required to decorate marks such as lettering provided on sidewalls with white rubber.

[0003] On the other hand, since the tires are usually stacked sideways for transportation, store display, etc., the white mark is scratched or comes into contact with the black rubber portion of another tire. The antioxidant migrates from the black rubber portion, and contamination such as discoloration or color transfer easily occurs.

[0004] For this purpose, conventionally, a protective tape is attached to a white mark to protect the surface thereof. However, while this product exhibits a high protective effect against the above-mentioned trauma and contamination, it takes time and effort to stick, and it takes time to remove the adhesive because it is denatured due to heat during store display or the adhesive remains on the mark. Has disadvantages.

Therefore, in recent years, instead of using a protective tape, an aqueous paint is applied to form a protective film so that the protective film can be removed by washing with water. Inevitability is inevitable,
These things are often problematic.

Accordingly, one object of the present invention is to provide a solution containing a film forming agent comprising a vinyl resin or a polyamide resin,
Applying an inorganic thickener containing silicon dioxide and aluminum oxide to adjust the viscosity, applying a uniform and sufficient film thickness of a water-removable protective film with excellent strength and flexibility. An object of the present invention is to provide a film-forming coating agent which can be formed and which can greatly improve stain resistance and trauma resistance.

It is another object of the present invention to provide a tire in which the surface of a white rubber is coated by applying the film-forming coating agent, and the occurrence of damage, contamination, and the like in a white mark is more effectively prevented.

[0008]

In order to achieve the above object, the invention of a film-forming coating composition according to claim 1 is to form at least one resin selected from a vinyl resin and a polyamide resin in a solvent. The viscosity is adjusted to 1 to 10000 cps by blending an inorganic thickener containing silicon dioxide and aluminum oxide into a solution contained as an agent.

Further, in the invention of a film-forming coating material according to claim 2, the thickener is a clay mineral.

In a third aspect of the present invention, the clay mineral is montmorillonite and bentonite containing montmorillonite as a main component.

According to a fourth aspect of the present invention, there is provided a tire according to the present invention, wherein the film-forming coating agent is applied to a surface of a white rubber provided on the tire, so that a vinyl resin and a polyamide resin are applied to the surface of the white rubber. It is characterized in that a protective film comprising at least one selected resin film-forming material and an inorganic water-soluble thickener is formed to a thickness of 5 to 100 μm.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the invention of the film-forming coating agent of the present application will be described with reference to the drawings, together with an embodiment of the invention of a tire to which the coating agent is applied. In FIG. 1, the tire 1 has a protective film 3 formed on the surface of a white rubber 2 so as to be able to be washed and removed by applying a film-forming coating agent.

In the present embodiment, the tire 1 has a tread 4
The carcass 7 extends from the first through the sidewall portion 5 to the bead portion 6, and the white rubber 2 is embedded outside the carcass 7 and in the sidewall portion 5. White rubber 2
A white mark 9 such as a character symbol such as a trademark or a product number or a design is exposed by partially exposing the tire surface.

The protective film 3 covering the surface of the white mark 9 is formed by applying a film forming coating.

The film-forming coating material contains at least one resin selected from a vinyl resin and a polyamide resin in a solvent.
The viscosity is adjusted to 1 to 10,000 cps by blending an inorganic thickener containing silicon dioxide and aluminum oxide into a solution containing two resins as a film forming agent.

Here, as the solvent, water, an organic solvent that dissolves in water, or a mixed solvent obtained by mixing these (hereinafter sometimes collectively referred to as an aqueous solvent) can be used. From the viewpoint of the drying time, low molecular alcohols such as methyl alcohol and ethyl alcohol can be suitably used.

The vinyl-based resin and the polyamide-based resin used as the film-forming agent are generally known as a resin material for forming a film such as a paint, and can impart strength and flexibility to a protective film. This film forming agent needs to easily disperse or dissolve its solid content in the aqueous solvent, thereby forming a colloidal dispersion type or water-soluble resin type solution. For this purpose, the film-forming agent is adjusted to a low molecular weight or partially modified with a hydrophilic group such as an acryl group to impart dispersibility or solubility in the aqueous solvent. Further, after the film is formed, the hydrophilic group remains as it is, so that it can be removed by washing with water.

The vinyl resin is a polymer obtained by polymerizing a monomer having a vinyl group. Particularly, the vinyl resin having high solubility in water and low-molecular alcohols includes polyacrylic acid and polymethyl acrylate. And acrylic-modified vinyl resins such as polyethyl acrylate, polymethyl methacrylate, and polyethyl methacrylate, and polyvinyl acetate, and these can be preferably used.

The polyamide resin is a polymer having an amide bond in the main chain, and in the present application, means a fatty acid polyamide resin. In particular, a polyamide resin for a coating obtained by condensation of a fatty acid with a bifunctional or polyfunctional amine is suitable because it is well soluble in the low-molecular alcohol.

As the film-forming agent, a vinyl-based resin and a polyamide-based resin may be used alone or in combination of two or more. The amount of the solid content of the film-forming agent per 100 parts by weight of the solvent is 10%. It is preferable to set it to 20 parts by weight.

Next, an inorganic thickener containing silicon dioxide and aluminum oxide is added to the solution.

Clay minerals are examples of such thickeners.
The viscosity of the film-forming coating material can be easily increased and adjusted, for example, by adsorbing moisture or the like, swelling in a paste form, exhibiting plasticity or tackiness.

The increase in the viscosity prevents the coating agent from dripping from the application surface, so that the protective film 3 can be formed with a uniform and sufficient thickness. In addition, since the film-forming agent contains inorganic silicon dioxide and aluminum oxide, the protective film 3 can be appropriately hardened while maintaining the flexibility of the film-forming agent, and has a strength against damage due to a synergistic action with the increase in thickness. (Trauma resistance) can be greatly improved. Further, the compounding of the thickener has an effect of preventing the penetration of a drug such as an antioxidant from the outside, and in combination with the hardening and the increase in thickness, color transfer and discoloration from an adjacent tire are caused. , Etc., can be greatly improved. For this purpose, the thickener is the total solid content of the film-forming coating composition.
It is preferable to mix 5 to 15 parts by weight with respect to 00 parts by weight.

As the thickener, it is preferable to use montmorillonite which is particularly excellent in swellability and bentonite containing montmorillonite as a main component. These have a strong thixotropic effect, that is, a property of high static viscosity and low dynamic viscosity. Therefore, since the static viscosity is high, the dripping of the coating agent can be further prevented and the film thickness can be further increased, and the low dynamic viscosity enables the coating work using a spray gun, for example, to be possible and easy. Becomes

Here, the range of the viscosity adjusted by the thickener is 1 to 10000 cps, and if it is less than 1 cps, the coating material is repelled from the coated surface and a required film thickness cannot be obtained. On the contrary, if the viscosity is 10,000 cps, the viscosity is too high and the coating performance is impaired. An increase in the film thickness due to the recoating is not preferable because it causes a significant decrease in working efficiency. Therefore, in order to obtain a sufficient film thickness by one spraying with a spray gun, 1000 to 4000 cps is required.
It is preferable to set the viscosity range. If it exceeds 4000 cps, the spray amount from the spray gun tends to decrease due to high viscosity.

On the other hand, the protective film 3 has an improved resistance to trauma and stain as the film thickness increases, and the film thickness for securing the necessary protective effect is 5 to 100 μm.
m. When the thickness is less than 5 μm, the protective effect is insufficient. On the other hand, when the thickness exceeds 100 μm, the followability to bending is poor, and the protective coating 3 tends to fall off the tire, and the drying time of the coating agent is unnecessarily lengthened. Therefore, it is preferably in the range of 30 to 70 μm.

[0027]

EXAMPLES A film-forming coating material was prepared according to the specifications shown in Table 1 using a solution containing a thickener in a mixed solvent of methyl alcohol and ethyl alcohol. In addition, each film-forming coating agent is applied to a white rubber plate-shaped test piece using a spray gun to form a protective film on the surface of the test piece. The results are compared and the results are shown in Table 1.

Polyvinyl acetate alcohol is used as the vinyl resin of the film-forming agent, 6 nylon is used as the polyamide resin, and bentonite is used as the thickener.

The coating was performed using an air spray gun under the following conditions.・ Nozzle diameter: φ1.0mm ・ Paint tank pressure: 0 kg / cm ² … suction type ・ Spray air pressure: 5.0 kg / cm ²・ Application time: about 3 seconds… Natural drying at room temperature

"Stain resistance test": A black rubber piece of the same size as the above test piece was prepared from a usual rubber for sidewalls (mixture of natural rubber and butadiene rubber) containing an antioxidant. The test piece and the test piece were superimposed on each other, sandwiched in a vise and pressure-bonded, and left in an oven at 100 ° C. for 24 hours under the pressure-bonded state.

Thereafter, the test piece whose protective film was washed away with water was exposed to sunlight, and thereafter, the degree of discoloration of the test piece from white to brown (contamination degree) was visually compared.
In addition, the evaluation was performed on a scale of 5 in which the degree of discoloration of Comparative Example 1 was defined as contamination degree 1 (worst) and the color of the new white rubber before contamination was designated as contamination degree 5 (best). The reason for exposure to sunlight is that the antioxidant in the black rubber piece migrates to the white rubber through the protective film in the oven, but the migrated antioxidant is dispersed in the white rubber. This is because the comparison of the degree of contamination is ambiguous and therefore once exposed to sunlight, which causes the antioxidant to migrate and concentrate on the surface.

"Followability test" A protective film was spray-coated on the bent portion of a dumbbell-shaped sample, and subjected to a bending test 1000 times at 50% strain using a dematcher bending tester, and the area of the peeled protective film was measured. Were compared. The evaluation was performed in five stages, with Comparative Example 2 having a peeling degree of 1 and a state without peeling having a peeling degree of 5.

[0033]

[Table 1]

As shown in Table 1, in the examples, since a predetermined thickening agent is added to the film-forming coating material, it is possible to confirm that excellent stain resistance can be exhibited without impairing the followability.

[0035]

According to the invention of the film forming coating agent, the viscosity is adjusted by mixing an inorganic thickener containing silicon dioxide and aluminum oxide with a solution containing a film forming agent composed of a vinyl resin or a polyamide resin. As a result, a water-removable protective film having excellent strength and flexibility can be applied and formed with a uniform and sufficient film thickness, and the stain resistance and trauma resistance can be greatly improved.

In the tire invention, since the white rubber is covered with the protective film formed by the film-forming coating agent, it is possible to more effectively prevent the white mark from being damaged or contaminated.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tire according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tire 2 White rubber 3 Protective film

Claims (4)

[Claims] An inorganic thickener containing silicon dioxide and aluminum oxide is mixed with a solution containing at least one resin selected from a vinyl resin and a polyamide resin in a solvent as a film-forming agent. A film-forming coating material characterized in that the viscosity is adjusted to 1 to 10000 cps by doing so. 2. The film-forming coating composition according to claim 1, wherein said thickener is a clay mineral. 3. The coating material according to claim 2, wherein the clay mineral is montmorillonite and bentonite containing montmorillonite as a main component. 4. The method of claim 1, wherein the film-forming coating composition is applied to a surface of a white rubber provided on a tire, so that at least one selected from a vinyl resin and a polyamide resin is applied to the surface of the white rubber. A tire characterized in that a protective film comprising a resin film-forming material and an inorganic thickener containing silicon dioxide and aluminum oxide is formed to a thickness of 5 to 100 μm.