JP2013144289A - Rubber coating method, coating material for rubber used in the rubber coating method, coating composition for rubber, and base treatment agent for rubber coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber coating method, a coating material for rubber used in the rubber coating method, and a base treatment agent for rubber coating super in adhesion to rubber of the coating material so that processes are few and do not need much labor and time.SOLUTION: The rubber coating method includes applying a base treatment agent to the rubber surface and then applying an urethane-based coating material thereonto, wherein the base treatment agent contains a plasticizer which is at least one selected from the group consisting of phthalic esters, aliphatic dibasic acid esters, glycolic acid esters, phosphate esters, and alkylene oxide adducts of aliphatic alcohols.

Description

  The present invention relates to a rubber coating method, a rubber coating material used in the rubber coating method, a rubber coating composition, and a surface treatment agent for rubber coating.

  Rubber is mainly used for automobile / vehicle parts, electrical parts, water supply parts, optical rubber, medical rubber, sports facilities and equipment, playground equipment, hydraulic and pneumatic equipment, road signs and safety parts. In recent years, in these applications, rubber is required to have conditions such as coloring for beautifying finishes, prevention of ozone deterioration, modification of the rubber surface (providing water repellency, oil repellency, hydrophilicity), and flame retardancy. It is coming.

  However, there is a fixed concept that it has been difficult to color conventional rubbers by painting, and the development of rubber coatings has not progressed.

Patent Document 1 describes a glossing method capable of forming a glossy coating having excellent adhesion to tires and durability against frictional heat and car washing.
However, in the method described in Patent Document 1, in order to remove the silicone on the tire surface, the tire surface is washed with a solution containing at least one alkylene oxide adduct of an aliphatic alcohol, and then the tire surface is washed with 4 wt% to After washing with an aqueous solution containing 20% by weight, wiping with water and drying, it is necessary to apply an aqueous gloss composition composed of a urethane resin. Also, it was not sufficient in terms of adhesion to rubber.

JP 2009-155620 A

The present invention has been made to solve the above-described problems, and provides a rubber coating method that has few steps, does not require much labor and time, and has excellent adhesion of paint to rubber. Is.
The present invention also provides a rubber coating, a rubber coating composition, and a rubber coating base treatment agent used in the rubber coating method.

  The invention according to claim 1 is a rubber coating method in which a surface treatment agent is applied to a rubber surface, and then a urethane-based paint is applied thereon, wherein the surface treatment agent contains a plasticizer, and the plasticizer is , Phthalic acid ester, aliphatic dibasic acid ester, glycol ester acid, phosphoric acid ester, alkylsulfonic acid phenyl ester and at least one selected from the group consisting of alkylene oxide adducts of aliphatic alcohols represented by the following formula It is related with the rubber coating method characterized by being.

The invention according to claim 2 relates to the rubber coating method according to claim 1, wherein the plasticizer in the surface treatment agent is applied to the rubber surface at 0.5 to 30 g / m ² .

  The invention according to claim 3 is that the surface treatment agent contains an organic solvent, and the organic solvent is an alcohol solvent such as isopropyl alcohol or methanol, a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, and xylene. 3. The rubber coating method according to claim 1, wherein the rubber coating method is at least one selected from the group consisting of aromatic solvents.

  The invention according to claim 4 relates to the rubber coating method according to any one of claims 1 to 3, wherein the urethane-based paint contains a water-based urethane resin.

  The invention according to claim 5 relates to the rubber coating method according to claim 4, wherein the urethane-based paint further contains an acrylic resin.

  The invention according to claim 6 relates to the rubber coating method according to any one of claims 1 to 5, characterized in that the surface treatment agent contains an aqueous urethane resin.

  The invention according to claim 7 is a rubber paint containing a ground treatment agent and a urethane paint, wherein the ground treatment agent contains a plasticizer, and the plasticizer is a phthalate ester or an aliphatic dibasic acid ester. A coating material for rubber, characterized in that it is at least one selected from the group consisting of an alkylene oxide adduct of an aliphatic alcohol represented by the following formula: glycol ester acid, phosphoric acid ester, alkylsulfonic acid phenyl ester .

  The invention according to claim 8 relates to the rubber paint according to claim 7, wherein the urethane-based paint contains a water-based urethane resin.

  The invention according to claim 9 relates to the rubber paint according to claim 8, wherein the urethane-based paint further contains an acrylic resin.

  The invention according to claim 10 includes 20 to 50 parts by weight of at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol with respect to 100 parts by weight of the rubber paint. The present invention relates to the rubber paint according to any one of the above.

  The invention according to claim 11 relates to the rubber paint according to any one of claims 7 to 10, wherein the isocyanate curing agent is contained in an amount of 5 to 20 parts by weight with respect to 100 parts by weight of the rubber paint.

  According to a twelfth aspect of the invention, the urethane-based paint includes a color pigment and a viscosity modifier, the viscosity modifier is made of fermented cellulose and / or laponite, and the content of the viscosity modifier is 0.02 to 3 The rubber paint according to any one of claims 7 to 11, characterized in that the viscosity is 10 to 500 cps at 20 ° C and the particle diameter of the color pigment is 30 µm or less. .

  The invention according to claim 13 relates to the rubber paint according to claim 12, wherein the viscosity is 20 to 300 cps at 20 ° C.

  The invention according to claim 14 relates to the rubber paint according to claim 12 or 13, which is for inkjet.

  The invention according to claim 15 is a rubber coating composition containing a plasticizer and an aqueous urethane resin, wherein the plasticizer is a phthalate ester, an aliphatic dibasic acid ester, a glycol ester acid, a phosphate ester, The present invention relates to a rubber coating composition, characterized in that it is at least one selected from the group consisting of alkylsulfonic acid phenyl ester and an alkylene oxide adduct of an aliphatic alcohol represented by the following formula.

  The invention according to claim 16 relates to the rubber coating composition according to claim 15, further comprising an acrylic resin.

  The invention according to claim 17 is characterized in that at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol is contained in an amount of 20 to 50 parts by weight with respect to 100 parts by weight of the rubber coating composition. Or it is related with the coating composition for rubbers of 16.

  The invention according to claim 18 includes 5 to 20 parts by weight of an isocyanate curing agent with respect to 100 parts by weight of the rubber coating composition, and the rubber coating composition according to any one of claims 15 to 17 Related to things.

  The invention according to claim 19 further includes a color pigment and a viscosity modifier, wherein the viscosity modifier is made of fermented cellulose and / or laponite, and the content of the viscosity modifier is 0.02 to 3% by weight. 19. The rubber coating composition according to claim 15, wherein the viscosity is 10 to 500 cps at 20 ° C., and the particle diameter of the color pigment is 30 μm or less.

  The invention according to claim 20 relates to the rubber coating composition according to claim 19, wherein the viscosity is 20 to 300 cps at 20 ° C.

  The invention according to claim 21 relates to the rubber coating composition according to claim 19 or 20, which is for inkjet.

  The invention according to claim 22 contains a plasticizer, and the plasticizer is represented by the following formula: phthalic acid ester, aliphatic dibasic acid ester, glycol ester acid, phosphoric acid ester, alkylsulfonic acid phenyl ester The present invention relates to a surface treatment agent for rubber coating, which is at least one selected from the group consisting of an alkylene oxide adduct of an aliphatic alcohol.

  The invention according to claim 23 relates to a ground coating agent for rubber coating according to claim 22, characterized in that it contains an aqueous urethane resin.

According to the first aspect of the present invention, there is provided a rubber coating method in which a surface treatment agent is applied to a rubber surface and then a urethane-based paint is applied thereon, wherein the surface treatment agent contains a plasticizer, The agent is selected from the group consisting of phthalic acid esters, aliphatic dibasic acid esters, glycol ester acids, phosphoric acid esters, alkylsulfonic acid phenyl esters, and alkylene oxide adducts of aliphatic alcohols represented by the above formula (Formula 1). Because it is a rubber coating method that is at least one selected, it is not necessary to wipe off the surface treatment agent, and it is only necessary to apply urethane-based paint over the surface treatment agent. An unnecessary rubber coating method can be provided. Moreover, the rubber coating method excellent in the adhesiveness to the rubber | gum of urethane type coating can be provided.
Further, since the urethane-based paint can be applied to the rubber surface with good adhesion, the rubber can be colored and the rubber surface can be beautifully finished. Moreover, ozone deterioration can be prevented and the rubber surface can be modified (providing water repellency, oil repellency, hydrophilicity), and the rubber can be made flame retardant.

According to the invention which concerns on Claim 2, when the plasticizer in a surface treating agent is apply | coated to the rubber surface at 0.5-30 g / m < ² >, the quantity of a surface treating agent may become insufficient or excessive. And a rubber coating method having excellent adhesion of the urethane-based paint. In addition, the urethane-based paint and the plasticizer in the base treatment agent can be integrated to form a film on the rubber surface, and the adhesion of the paint to rubber can be further improved.

  According to the invention of claim 3, the surface treatment agent contains an organic solvent, the organic solvent is an alcohol solvent such as isopropyl alcohol and methanol, a ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone, and xylene. By being at least one selected from the group consisting of aromatic solvents, the surface treatment agent can be easily diluted, so that the workability of applying the surface treatment agent can be improved.

  According to the invention which concerns on Claim 4, when the urethane type coating material contains water-based urethane resin, the adhesive improvement effect by a base-treatment agent can be heightened. In addition, a coating film excellent in wear resistance can be formed on the rubber surface, and a coating film that can follow the elongation of low-hardness rubber can be formed on the rubber surface.

  According to the invention which concerns on Claim 5, when a urethane type coating material contains an acrylic resin further, it can be set as the rubber coating method which can be used versatilely.

  According to the invention of claim 6, since the surface treatment agent contains an aqueous urethane resin, the viscosity of the surface treatment agent is increased and a thin film is formed on the rubber surface, so that the surface treatment agent itself adheres to the rubber surface. Can be improved. In addition, when the urethane paint is applied from above, it is possible to prevent the surface treatment agent from flowing down from the rubber surface and reducing the adhesion of the urethane paint.

According to the seventh aspect of the present invention, there is provided a rubber paint containing a base treatment agent and a urethane-based paint, wherein the base treatment agent contains a plasticizer, and the plasticizer is a phthalate ester, aliphatic 2 For rubber that is at least one selected from the group consisting of basic acid esters, glycol ester acids, phosphoric acid esters, alkylsulfonic acid phenyl esters, and alkylene oxide adducts of aliphatic alcohols represented by the above formula (Formula 2) Since it is a paint, it is possible to reduce the number of processes and the need for a lot of labor and time when painting. Moreover, it can be set as the rubber coating material excellent in the adhesiveness to rubber | gum.
As a result, the rubber surface can be coated with good adhesion, so that the rubber can be colored and the rubber surface can be beautifully finished. Moreover, ozone deterioration can be prevented and the rubber surface can be modified (providing water repellency, oil repellency, hydrophilicity), and the rubber can be made flame retardant.

  According to the invention of claim 8, since the urethane-based paint contains a water-based urethane resin, it is possible to form a coating film excellent in abrasion resistance on the rubber surface and follow the elongation of the low hardness rubber. A coating film that can be formed can be formed on the rubber surface.

  According to the invention which concerns on Claim 9, it can be set as the rubber coating material which can be used for many uses because a urethane type coating material contains an acrylic resin further.

  According to the invention according to claim 10, by setting at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol as a rubber paint containing 20 to 50 parts by weight with respect to 100 parts by weight of the rubber paint, The drying property of the paint can be improved.

  According to the eleventh aspect of the present invention, the isocyanate curing agent is a rubber paint containing 5 to 20 parts by weight with respect to 100 parts by weight of the rubber paint, thereby preventing the vulcanizing agent and oil from the rubber and tire, and preventing deterioration. The phenomenon of yellowing of the coating film can be prevented by the agent. This is particularly effective in white paint.

  According to the invention of claim 12, the urethane paint includes a color pigment and a viscosity modifier, the viscosity modifier is made of fermented cellulose and / or laponite, and the content of the viscosity modifier is 0.02 to 0.02. An inorganic pigment having a large specific gravity such as a white pigment was used because it was 3% by weight, a viscosity was 10 to 500 cps at 20 ° C., and the particle diameter of the colored pigment was 30 μm or less. Even if the viscosity is low, precipitation of the pigment in the rubber coating can be prevented. Thereby, it is possible to prevent the coloring of the coating from fading, and it becomes unnecessary to constantly stir the paint.

  According to the thirteenth aspect of the present invention, the rubber paint having a viscosity of 20 to 300 cps at 20 [deg.] C. makes it difficult for the paint after coating to drip and easily sprays when used in inkjet. be able to.

  According to the invention of claim 14, it is possible to prevent the coloring of the coating from fading, and it is not necessary to constantly stir the paint. In addition, since there is no occurrence of clogging of the nozzle of the ink jet, as a rubber paint for ink jet It can be used suitably.

The invention according to claim 15 is a rubber coating composition containing a plasticizer and an aqueous urethane resin, wherein the plasticizer is a phthalate ester, an aliphatic dibasic acid ester, a glycol ester acid, or phosphoric acid. A coating composition for rubber which is at least one selected from the group consisting of an ester, an alkylsulfonic acid phenyl ester, and an alkylene oxide adduct of an aliphatic alcohol represented by the above formula (Formula 3). In this case, it is possible to reduce the number of steps and not to require much labor and time. Moreover, it can be set as the rubber coating composition excellent in the adhesiveness to rubber | gum.
As a result, the rubber surface can be coated with good adhesion, so that the rubber can be colored and the rubber surface can be beautifully finished. Moreover, ozone deterioration can be prevented and the rubber surface can be modified (providing water repellency, oil repellency, hydrophilicity), and the rubber can be made flame retardant.
In addition, a coating film excellent in wear resistance can be formed on the rubber surface, and a coating film that can follow the elongation of low-hardness rubber can be formed on the rubber surface.

  According to the invention which concerns on Claim 16, it can be set as the rubber coating composition which can be used for many uses because the rubber coating composition contains an acrylic resin further.

  According to the invention of claim 17, a rubber coating composition containing at least one selected from the group consisting of ethanol, methanol, and isopropyl alcohol is 20 to 50 parts by weight with respect to 100 parts by weight of the rubber coating. Thus, the drying property of the paint can be improved.

  According to the invention of claim 18, by setting the isocyanate curing agent to a rubber coating composition containing 5 to 20 parts by weight with respect to 100 parts by weight of the rubber coating, a vulcanizing agent and an oil component coming out of rubber and tires, The deterioration inhibitor can prevent the phenomenon of yellowing of the coating film. This is particularly effective in white paint.

  According to the invention of claim 19, further comprising a color pigment and a viscosity modifier, the viscosity modifier is made of fermented cellulose and / or laponite, and the content of the viscosity modifier is 0.02 to 3% by weight. In the case of using an inorganic pigment having a large specific gravity such as a white pigment, the viscosity is 10 to 500 cps at 20 ° C., and the particle diameter of the colored pigment is 30 μm or less. Even if the viscosity is low, precipitation of the pigment in the rubber coating can be prevented. Thereby, it is possible to prevent the coloring of the coating from fading, and it becomes unnecessary to constantly stir the paint.

  According to the invention of claim 20, because the rubber coating composition has a viscosity of 20 to 300 cps at 20 ° C., the paint after coating is difficult to drip and is easy to be sprayed when used for inkjet. It can be a composition.

  According to the invention of claim 21, since it is possible to prevent the coloring of the coating from fading, it is not necessary to constantly stir the paint, and there is no occurrence of clogging of the nozzles of the ink jet. It can be suitably used as a product.

  According to the invention of claim 22, it contains a plasticizer, and the plasticizer is a phthalate ester, an aliphatic dibasic acid ester, a glycol ester acid, a phosphate ester, an alkylsulfonic acid phenyl ester, 4) It is possible to improve the adhesion of paint to rubber by being a ground treatment agent for rubber coating that is at least one selected from the group consisting of alkylene oxide adducts of aliphatic alcohols represented by 4). .

  According to the invention of claim 23, since the surface treatment agent for rubber coating contains a water-based urethane resin, the surface treatment agent has a high viscosity and forms a thin film on the rubber surface. The adhesion to the surface can be improved. In addition, when the urethane paint is applied from above, it is possible to prevent the surface treatment agent from flowing down from the rubber surface and reducing the adhesion of the urethane paint.

It is a graph which shows the change of the gloss retention with the irradiation time of an ultraviolet-ray of the rubber coated by the coating method of Example 2. It is a graph which shows the change of the color difference ((DELTA) E) with the irradiation time of an ultraviolet-ray of the rubber coated with the coating method of Example 2. FIG. It is the surface photograph (x300) of the rubber | gum and the unpainted rubber which were painted by the coating method of Example 2 after 300 hours of ultraviolet irradiation. It is the surface photograph (* 300) of 2000 hours after ultraviolet irradiation of the rubber coated by the coating method of Example 8, and an unpainted rubber.

  Hereinafter, the rubber coating method according to the present invention and the rubber coating, the rubber coating composition and the rubber coating base treatment agent used in the rubber coating method will be described.

In the rubber coating method according to the present invention, first, a base treatment agent is applied to the rubber surface.
The surface treatment agent can contain an organic solvent. The organic solvent is not limited to these, but alcohol solvents such as isopropyl alcohol and methanol, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic solvents such as xylene are preferably used. These can be used alone or in combination.

The ground treatment agent contains a plasticizer. As the plasticizer, phthalic acid ester, aliphatic dibasic acid ester, glycol ester acid, phosphoric acid ester, alkylsulfonic acid phenyl ester, and alkylene oxide adduct of aliphatic alcohol are used alone or in combination. be able to.
The base treatment agent contains a plasticizer and an organic solvent in a weight ratio of 1:99 to 100: 0, preferably 40:60 to 60:40.

As the phthalate ester, dibutyl phthalate, dioctyl phthalate, diisononyl phthalate and the like can be used.
As the aliphatic dibasic acid ester, diisononyl adipate, diethyl succinate or the like can be used.
As glycol ester acid, ethylene glycol acetate or the like can be used.
As phosphate ester, tributyl phosphate etc. can be used.
As the alkylsulfonic acid phenyl ester, mezamol (manufactured by LANXESS) or the like can be used.
As the alkylene oxide adduct of an aliphatic alcohol, a compound represented by the following formula can be used.

  From the experimental knowledge of the present inventor, it has been found that the deterioration inhibitor, wax, silicone, and elongation of rubber contained in the rubber inhibit the adhesion between the rubber and the paint.

  Degradation inhibitors (anti-aging agents, antioxidants, ozone degradation inhibitors) are included in rubber to prevent the process of rubber from reacting with sunlight, ozone, etc. and growing into cracks. This deterioration preventing agent tends to float on the rubber surface and causes bleeding.

  Wax is contained in rubber in order to improve the ozone resistance of rubber having a double bond. The wax gradually emerges on the rubber surface to form a thin film (bloom) and protect the rubber surface, which causes powder blowing due to the bloom phenomenon.

  Silicone is contained in rubber as a mold release agent and is used at the time of rubber molding. In car tires, it may be used as gloss or water repellent. This silicone also causes poor adhesion of the paint.

  Even if the coating film is in close contact, if the coating film itself is not soft, it will not follow the flexible movement of the rubber, causing cracks and peeling.

  The surface treatment agent according to the present invention has a structure as described above, so that it has good permeability to rubber, and these deterioration inhibitors, wax, silicone, and other substances that inhibit the adhesion between rubber and paint are removed. Therefore, it is possible to improve the adhesion between the rubber and the urethane paint described later. Moreover, since it is excellent in a softness | flexibility and can follow the elongation of rubber | gum, generation | occurrence | production and peeling of the crack of a coating film can be prevented.

The base treatment agent can contain an aqueous urethane resin. As a result, the surface treatment agent has a high viscosity and is difficult to be repelled from the rubber surface. Therefore, a thin film can be formed on the rubber surface. Thereby, the adhesiveness of the surface treatment agent itself to the rubber surface is improved. In addition, when the urethane paint is applied from above the ground treatment agent, the ground treatment agent does not flow down from the rubber surface, so the adhesion of the urethane paint can also be improved.
The base treatment agent can contain an acrylic resin in addition to the aqueous urethane resin. By containing an acrylic resin, it can be used for many purposes.

After applying the surface treatment agent to the rubber surface, a urethane-based paint is applied thereon.
It is preferable that the plasticizer in the ground treatment agent is applied to the rubber surface at 0.5 to 30 g / m ² . As a result, the urethane paint and the plasticizer in the surface treatment agent are integrated into a rubber paint, and a rubber paint film can be formed on the rubber surface, further improving the adhesion of the paint to rubber. be able to.
If the coating amount is less than 0.5 g / m ² , the amount of the surface treatment agent on the rubber surface is insufficient, and the urethane paint cannot be sufficiently adhered, which is not preferable. If the coating amount exceeds 30 g / m ² , the amount of the surface treatment agent on the rubber surface becomes excessive, and the urethane paint cannot be sufficiently adhered, which is not preferable.
Alternatively, the same plasticizer and urethane paint as those contained in the base treatment agent can be mixed in advance to form a rubber paint, and this rubber paint can be directly applied to the rubber surface.
In this case, the plasticizer content is preferably 1 to 10% by weight, more preferably 2 to 5% by weight. When the content of the plasticizer is less than 1% by weight, it is not preferable in terms of adhesion. If the content of the plasticizer exceeds 10%, the coated surface becomes sticky, which is not preferable.

The urethane-based paint preferably contains an aqueous urethane resin. Examples of urethane-based paints include Turner Rubber Paint RF-200, YN-1000, and YN-4000 (all manufactured by Turner Color Co., Ltd.).
The urethane-based paint may contain an acrylic resin in addition to the water-based urethane resin. Thereby, it can be set as the rubber coating method which can be used versatilely.
In addition to the urethane-based paint, a coloring pigment, an additive, and water can be appropriately blended.
As the color pigment, those generally used for paints can be used. For example, titanium can be used as a white pigment, cyanine blue as a blue pigment, and carbon as a black pigment.

Urethane paint Turner Rubber Paint YN-1000 (manufactured by Turner Color Co., Ltd.) is a urethane paint excellent in abrasion resistance, which contains water-based urethane resin, color pigment, additive, and water as components. It is suitably used for escalator handrail rubber.
Urethane-based paint Turner Rubber Paint RF-200 (manufactured by Turner Color Co., Ltd.) is a urethane-based paint that can be used for various purposes, comprising water-based urethane resin, acrylic resin, color pigment, additive, and water as components. It is suitably used for rubber fences, rubber signs, and models.
Urethane paint Turner Rubber Paint YN-4000 (made by Turner Color Co., Ltd.) is a urethane system that has water-based urethane resin, color pigments, additives, and water, and has excellent flexibility to follow the elongation of balloons. It is a paint. It is suitably used for low-hardness rubber, rubber balloons, and anti-vibration rubber.
When applying a urethane type coating after application | coating of a surface treating agent, it is preferable that the viscosity of a urethane type coating is 500-3000 cps at 20 degreeC.

  The rubber paint of the present invention may contain 20 to 50 parts by weight of at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol with respect to 100 parts by weight of the rubber paint. Thereby, the drying property of a coating material can be improved.

The rubber paint of the present invention may contain 5 to 20 parts by weight of an isocyanate curing agent with respect to 100 parts by weight of the rubber paint. Thereby, the phenomenon which a coating film yellows with the vulcanizing agent, oil component, and deterioration prevention agent which come out from rubber | gum or a tire can be prevented. This is particularly effective in white paint.
As the isocyanate curing agent, Vernock DNW-5000 (manufactured by DIC) or the like can be used.

  The rubber paint of the present invention can be used for inkjet. In the following, only the matters specific to the rubber paint used in the inkjet will be described.

The ink jet rubber paint of the present invention can contain a color pigment, and can further contain a viscosity modifier.
As the viscosity modifier, fermented cellulose or laponite whose viscosity hardly changes due to a temperature change is preferably used.
The content of the viscosity modifier is preferably 0.02 to 3% by weight.
Fermented cellulose is a naturally-derived material having biodegradability obtained by aeration and stirring culture of a subspecies of acetic acid bacteria in an appropriate medium. For example, International Publication No. 2008/057985, JP 2009-161624 A Gazette, International Publication No. 2004/108164, JP 2007-98577 A, JP 2006-247971 A, JP 2004-249573 A, JP 11-279202 A, JP 3796613 A, Those described in Kaihei 10-231466, JP-A-10-95803, JP-A-2926210, JP-A-7-76198 and JP-A-6-1647 can be used.

  The viscosity of the ink coating rubber coating material of the present invention is preferably adjusted to 10 to 500 cps at 20 ° C., more preferably 20 to 300 cps, with a viscosity adjusting agent.

The particle diameter of the color pigment is preferably 30 μm or less.
The content of the color pigment varies depending on the color, but in the case of a white pigment, it is preferably 10 to 40% by weight, more preferably about 25% by weight, and in the case of a black or blue pigment, preferably 1 to 6% by weight, more preferably Is about 3% by weight.
In the case of a white pigment, it is necessary to increase the content for reasons of hiding power, and precipitation tends to occur.

In the ink jet rubber paint of the present invention, the viscosity is 10 to 500 cps at 20 ° C., more preferably 20 to 300 cps, and the particle diameter of the color pigment is 30 μm or less. Even when a pigment is used and the viscosity is low, precipitation of a colored pigment can be prevented, and the pigment can be used for inkjet.
If the viscosity of the urethane paint or rubber paint is less than 10 cps, the paint may flow down from the rubber surface or the paint may sag, which is not preferable.
If the viscosity of the urethane-based paint or rubber paint exceeds 500 cps, it is not preferable because printing by ink jet becomes difficult.
If the particle diameter of the color pigment exceeds 30 μm, ink jet clogging tends to occur, and printing cannot be performed.

  The rubber coating method according to the present invention and the rubber coating material, the rubber coating composition and the rubber coating base treatment agent used in the rubber coating method according to the present invention are described in more detail based on the following examples. It is not limited.

<Preparation of surface treatment agent>
Dibutyl phthalate was used as the surface treatment agent of Example 1, and a mixture of dibutyl phthalate and isopropyl alcohol (IPA) at a ratio (weight%) of 50:50 was used as the surface treatment agent of Example 2. In Example 2, instead of dibutyl phthalate as a plasticizer, dioctyl phthalate, diisononyl adipate, diethyl succinate, ethylene glycol acetate, tributyl phosphate, alkylene oxide adduct liquid (m = 1, equivalent to n = 1), mezamol (manufactured by LANXESS), diisononyl phthalate (DINP) (manufactured by J. Plus), and the same conditions as those in Examples 9 to 16, respectively. It was. In addition, those containing only isopropyl alcohol were used as the surface treatment agents of Comparative Examples 2 and 3, respectively, as the surface treatment agent of Comparative Example 1, a commercially available acrylic solvent, and a 30% aqueous sodium silicate solution.

<Application of surface treatment agent and urethane paint>
The surface treatment agents of Examples 1, 2, 9 to 16 and Comparative Examples 1 to 3 were applied to the surface of chloroprene rubber (CR rubber) so that the plasticizer was 15 g / m ² .
Subsequently, urethane-based paint Turner Rubber Paint RF-200 (manufactured by Turner Color Co., Ltd.) was applied from above the surface treatment agent.
In addition, the same conditions as in Example 2 were applied except that the plasticizer in the surface treatment agent was applied to the rubber surface so as to be 0.3, 0.5, 30, 40 g / m ² , respectively. Example 7 was made under the same conditions as Examples 3, 4, 5 and 6, except that the rubber to be coated was EPDM and the urethane-based paint was Turner Rubber Paint YN-1000 (manufactured by Turner Color Co., Ltd.). Further, Example 8 was the same as Example 7 except that the urethane-based paint was Turner Rubber Paint YN-4000 (manufactured by Turner Color Co., Ltd.).
The combinations are shown in Table 1 below.

Test 1 (Adhesion)
In the coating methods of Examples 1 to 6, 9 to 16 and Comparative Examples 1 to 3, a cross-cut test was performed, the cross-cut state after the tape was peeled off was visually confirmed, and the adhesion of the paint to rubber was evaluated. .
In the coating methods of Examples 1 to 6, 9 to 16 and Comparative Examples 1 to 3, natural rubber (NR), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), isoprene (IR), urethane (U ), Chlorosulfonated polyethylene (CSM), chloroprene rubber (CR), elastomer, and butyl rubber (IIR) were also evaluated in the same manner. The results are shown in Table 2 below.

From the results shown in Table 2, it is clear that the rubber paint by the coating method of the example is superior in adhesion to the rubber paint by the coating method of the comparative example.
A comparison of Examples 2 to 6, which plasticizer in the ground processing material is coated with urethane paint such that 0.5 to 30 g / ^{m 2} on the rubber surface, of less than 0.5 g / ^{m 2} It can be seen that the adhesiveness of the paint is excellent as compared with those exceeding 30 g / m ² .

Test 2 (water resistance)
The rubber coated with the paint by the coating methods of Examples 1 to 6, 9 to 16 and Comparative Examples 1 to 3 was immersed in water for 24 hours, and the swelling and peeling were visually evaluated.
No swelling or peeling of the paint was observed on the rubber coated with the paint by the coating methods of Examples 1 to 6 and 9 to 16.
On the other hand, swelling and peeling of the paint were partially observed on the rubber coated with the paint by the coating methods of Comparative Examples 1 to 3.

Test 3 (Elongation of paint film at low temperature)
The rubber | gum with which the coating material was painted with the coating method of Examples 1-6, 9-16 and Comparative Examples 1-3 performed the tension test in -20 degreeC based on JISK-6251.
No cracks or the like of the paint were found in the rubber coated with the paint by the coating methods of Examples 1 to 6 and 9 to 16.
On the other hand, some paint cracks were observed on the rubber coated with the paint by the coating methods of Comparative Examples 1-3.

Test 4 (weather resistance)
The rubber coated with the paint by the coating methods of Examples 2 and 8 was irradiated with ultraviolet rays with a xenon lamp in accordance with JIS K5600-7-7, and the weather resistance was evaluated.
FIG. 1 is a graph showing a change in the gloss of the rubber coated by the coating method of Example 2 when the gloss retention with respect to the irradiation time of ultraviolet rays, that is, the initial gloss is 100.
FIG. 2 is a graph showing the change in color difference (ΔE) of the rubber coated by the coating method of Example 2 with the irradiation time of ultraviolet rays.
FIG. 3 is a surface photograph (× 300) of rubber coated with the coating method of Example 2 and unpainted rubber after 300 hours of ultraviolet irradiation.
FIG. 4 is a surface photograph (× 300) of the rubber coated by the coating method of Example 8 and unpainted rubber after 2000 hours of ultraviolet irradiation.
As can be seen from the results of FIG. 1, the rubber coated with the paint by the coating method of Example 2 has a gloss retention of 100% even at an irradiation time of 700 hours, and is excellent in weather resistance. .
As can be seen from the results shown in FIG. 2, the rubber coated with the paint by the coating method of Example 2 shows no change in color difference (ΔE) even at an irradiation time of 300 hours, and is excellent in weather resistance. .
As can be seen from the photographs in FIGS. 3 and 4, cracks due to ozone degradation are observed on the unpainted rubber surface, whereas defects such as cracks are observed on the coating film on the rubber surfaces of Examples 2 and 8. It can be seen that the rubbers of the examples are excellent in weather resistance.

Test 5 (Abrasion resistance)
The rubber coated by the coating method of Example 7 was washed 20,000 times with a pig hair brush without a washing solution using a washability washing tester, and the wear resistance was visually evaluated.
No wear was observed on the rubber surface, and it was found that the rubber coated by the coating method of Example 7 was excellent in wear resistance.

Test 6 (repeated flexibility)
Repeated flexibility was evaluated by coating the escalator handrail by the coating method of Example 7 and measuring the gloss retention after operating the escalator for 13 hours per day for one month.
The gloss retention rate after operation was maintained at a gloss retention rate of 99% or more compared with that before the escalator operation. Therefore, it can be seen that the rubber coated by the coating method of Example 7 is excellent in repeated flexibility.

Test 7 (scratch resistance)
The rubber surface coated by the coating method of Example 7 was rubbed with a nail (corresponding to pencil hardness H) to evaluate scratch resistance.
Scratches are hardly seen on the rubber surface, and it can be seen that the rubber coated by the coating method of Example 7 is excellent in scratch resistance.

Test 8 (Cryogenic cycle test)
The rubber coated by the coating method of Example 7 was subjected to 6 cycles of −20 ° C. for 16 hours and room temperature of 8 hours, and visually evaluated whether there was any abnormality on the rubber surface.
As a result, no abnormality was found on the rubber surface.

Test 9 (low temperature bending test)
The rubber coated by the coating method of Example 7 was cooled to −20 ° C., bent and bent, and evaluated whether there was any abnormality on the rubber surface.
As a result, no abnormality was found on the rubber surface.

From the above, it can be seen that the rubber coated by the rubber coating method according to the present invention is excellent in paint adhesion, and exhibits excellent performance in weather resistance and other items.
Moreover, in any combination of the plasticizers of the base treatment agent of the example, the same effect as the example was obtained.

<Preparation of inkjet rubber paint>
A urethane-based paint Turner Rubber Paint YN-1000 Clear (Turner Color Co., Ltd.) with a base treatment agent mixed with dibutyl phthalate and isopropyl alcohol (IPA) in a ratio of 50:50 (wt%) Made by adding 0.2% by weight of fermented cellulose (Sun Artist H-PX (San-Eigen F.F.I.)).
Add 30 g of white pigment (CR97, Ishihara Sangyo) with a particle diameter of 10 μm or less and 0.2 g of fermented cellulose (Sun Artist H-PX (San-Eigen FFI Co., Ltd.)) as a viscosity modifier. The rubber coating material of Example 17 was adjusted to 250 cps.
In addition, parameters were changed as shown in Table 3 below to obtain rubber paints of Examples 18 to 28.
In the rubber paints of Examples 22 and 28, precipitation of white pigment was observed.

Test 10 (visual evaluation of inkjet coating)
The rubber paints of Examples 17 to 28 were applied to the surface of chloroprene rubber (CR rubber) by an inkjet coating apparatus so that dibutyl phthalate was 15 g / m ^2, and the coating state was visually evaluated.

The rubber paints of Examples 17 to 28 could all be applied to the CR rubber surface.
However, in the coating with the rubber paint of Example 17, dripping of the paint was observed because the viscosity of the paint was low. In addition, since the rubber coating material of Example 28 had large particles, precipitation of a white pigment was observed, and clogging occurred in an inkjet nozzle.

<Preparation of rubber paint for dryness evaluation>
Urethane paint Turner Rubber Paint YN-1000, which is a mixture of dibutyl phthalate and isopropyl alcohol (IPA) in a ratio of 50:50 (wt%), is used as a base treatment agent, and the rubber surface is washed to remove the thickener. It was mixed with clear (Turner Color Co., Ltd.).
Ethanol was added to this so that it might become 35 weight%, and it was set as the rubber coating material of Example 29. FIG.
Examples in which the amount of ethanol added was 15, 20, 50, 60, and 0% by weight were referred to as Examples 30, 31, 32, 33, and 34, respectively. The rubber coating material of Example 35 was obtained by using isopropyl alcohol instead of ethanol.

Test 11 (dryness)
The CR rubber surface was coated with dibutyl phthalate at 15 g / m ^2, and after 10 minutes and 20 minutes, the painted surface was touched with a finger, and the drying property was evaluated depending on whether or not the paint was applied to the finger.
In Examples 29, 31, 33, and 35, the painted surface was already dried after 10 minutes. In Examples 30, 33 and 34, the painted surface was not dried after 10 minutes, but the painted surface was already dried after 20 minutes.

<Preparation of paint for rubber for discoloration evaluation>
A mixture of dibutyl phthalate and isopropyl alcohol (IPA) in a ratio of 50:50 (wt%) was used as a base treatment agent, and the resultant was applied to the CR rubber surface so that dibutyl phthalate was 15 g / cm ² .
Next, 30 g of a white pigment (CR97, Ishihara Sangyo) having a particle diameter of 10 μm or less and 10 isocyanate curing agents (Bernock DNW-5000, manufactured by DIC Corporation) are applied to urethane paint Turner Rubber Paint YN-1000 Clear (manufactured by Turner Color Co., Ltd.). What was added so that it might become weight% was apply | coated from on the surface-treatment agent (Example 36).
Examples in which the addition amount of the isocyanate curing agent was 3, 5, 20, 25, and 0% by weight were regarded as Examples 37, 38, 39, 40, and 41, respectively.

Test 12 (discoloration)
One day after application, it was visually evaluated whether or not the painted surface was yellowed.
The painted surfaces of Examples 36, 38 and 39 showed no yellowing even after 7 days. The painted surfaces of Examples 37, 40, and 41 were slightly yellowed.

  The present invention relates to automobile / vehicle parts such as tires, packings, seals, etc., insulation equipment for electrical parts, hoses, water rubber parts such as rubber packings, optical rubbers used for cameras, binoculars, medical rubbers, baseball fields, Suitable for sports facilities and equipment such as tennis courts, golf courses, playground equipment, anti-vibration rubber for hydraulic and pneumatic equipment, and road signs and safety / security parts such as sponges, color cones (registered trademark), and retractable devices. Is.

Claims (23)

A rubber coating method in which a surface treatment agent is applied to a rubber surface, and then a urethane paint is applied thereon,
The base treatment agent contains a plasticizer, and the plasticizer is a phthalic acid ester, an aliphatic dibasic acid ester, a glycol ester acid, a phosphoric acid ester, an alkylsulfonic acid phenyl ester, and an aliphatic alcohol represented by the following formula: A rubber coating method characterized in that it is at least one selected from the group consisting of alkylene oxide adducts.
The rubber coating method according to claim 1, wherein the plasticizer in the surface treatment agent is applied to the rubber surface at 0.5 to 30 g / m ² .   The surface treatment agent contains an organic solvent, and the organic solvent comprises an alcohol solvent such as isopropyl alcohol and methanol, a ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone, and an aromatic solvent such as xylene. The rubber coating method according to claim 1, wherein the rubber coating method is at least one selected from the group.   The rubber coating method according to any one of claims 1 to 3, wherein the urethane-based paint contains a water-based urethane resin.   The rubber coating method according to claim 4, wherein the urethane-based paint further contains an acrylic resin.   The rubber coating method according to claim 1, wherein the surface treatment agent contains a water-based urethane resin. It is a paint for rubber containing a surface treatment agent and a urethane paint,
The base treatment agent contains a plasticizer, and the plasticizer is a phthalic acid ester, an aliphatic dibasic acid ester, a glycol ester acid, a phosphoric acid ester, an alkylsulfonic acid phenyl ester, and an aliphatic alcohol represented by the following formula: A rubber paint characterized in that it is at least one selected from the group consisting of adducts of alkylene oxide.
  The rubber paint according to claim 7, wherein the urethane-based paint contains a water-based urethane resin.   The rubber paint according to claim 8, wherein the urethane paint further contains an acrylic resin.   The rubber according to any one of claims 7 to 9, comprising 20 to 50 parts by weight of at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol with respect to 100 parts by weight of the rubber coating material. Paint.   11. The rubber paint according to claim 7, wherein the isocyanate curing agent is contained in an amount of 5 to 20 parts by weight per 100 parts by weight of the rubber paint. The urethane paint includes a color pigment and a viscosity modifier,
The viscosity modifier comprises fermented cellulose and / or laponite;
The content of the viscosity modifier is 0.02 to 3% by weight,
A viscosity of 10 to 500 cps at 20 ° C.,
The rubber paint according to any one of claims 7 to 11, wherein a particle diameter of the color pigment is 30 µm or less.   The rubber paint according to claim 12, wherein the viscosity is 20 to 300 cps at 20 ° C.   The rubber paint according to claim 12 or 13, which is for inkjet. A rubber coating composition containing a plasticizer and an aqueous urethane resin,
The plasticizer is selected from the group consisting of phthalic acid ester, aliphatic dibasic acid ester, glycol ester acid, phosphoric acid ester, alkylsulfonic acid phenyl ester, and an alkylene oxide adduct of an aliphatic alcohol represented by the following formula: A rubber coating composition, characterized in that it is at least one.
  The rubber coating composition according to claim 15, further comprising an acrylic resin.   The rubber coating composition according to claim 15 or 16, comprising 20 to 50 parts by weight of at least one selected from the group consisting of ethanol, methanol and isopropyl alcohol with respect to 100 parts by weight of the rubber coating composition. object.   18. The rubber coating composition according to claim 15, comprising 5 to 20 parts by weight of an isocyanate curing agent with respect to 100 parts by weight of the rubber coating composition. In addition, it contains a color pigment and a viscosity modifier,
The viscosity modifier comprises fermented cellulose and / or laponite;
The content of the viscosity modifier is 0.02 to 3% by weight,
A viscosity of 10 to 500 cps at 20 ° C.,
The rubber paint composition according to any one of claims 15 to 18, wherein the color pigment has a particle size of 30 µm or less.   The rubber coating composition according to claim 19, wherein the viscosity is 20 to 300 cps at 20 ° C.   The rubber coating composition according to claim 19 or 20, wherein the rubber coating composition is for inkjet. Containing a plasticizer, wherein the plasticizer is a phthalic acid ester, an aliphatic dibasic acid ester, a glycol ester acid, a phosphoric acid ester, an alkylsulfonic acid phenyl ester, and an alkylene oxide adduct of an aliphatic alcohol represented by the following formula: A surface treatment agent for rubber coating, characterized in that it is at least one selected from the group consisting of:
  23. The ground coating agent for rubber coating according to claim 22, comprising an aqueous urethane resin.