JPH11269287A - Water-repellent coating agent and method for forming high hardness water-repellent thin membrane using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-repellent coating agent excellent in hardness and abrasion resistance and furthermore, rich in water repellency, stain-proofing properties, resistance to wear and adhesion and a method for forming a high hardness water-repellent membrane using the same. SOLUTION: A desired water-repellent coating agent comprises an ultraviolet curable resin and a fluorine based surface modifier. A method for forming a high hardness water-repellent thin membrane 2 comprises the steps of coating said water-repellent coating agent on a substrate 1 to form an uncured layer; heating the resulting element at a temperature of not higher than 150 deg.C; and polymerizing the uncured layer by ultraviolet irradiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-repellent coating agent having excellent hardness and scratch resistance, and a method for forming a high-hardness water-repellent thin film using the same.

[0002]

2. Description of the Related Art It is well known that, when a solid surface is coated with a substance containing a fluorinated alkyl group (Rf group), the surface energy is remarkably reduced, high water and oil repellency is exhibited, and the friction coefficient is reduced. I have. Such a feature is sufficient if the Rf group is present only on the surface, but simply applying a commercially available water repellent to the substrate deteriorates the abrasion resistance of the water repellent layer. In order to solve this problem, for example, as described in JP-A-8-143690, an uncured underlayer containing an acrylic photopolymerization-curable paint and a polysiloxane composition having a silanol group was formed. When an uncured upper layer containing a silicon-based thermopolymerized curing paint and perfluoroalkoxylane is formed thereon and subjected to ultraviolet irradiation and heat treatment, fluorine-bonded groups bonded by siloxane bonds are present on the surface and inside. It has water repellency. In addition, most of the surface and the inside of the thin film are obtained by curing the silicone-based heat-resistant heat-curable composition and have excellent abrasion resistance.

[0003]

However, although the thin film thus formed has excellent water repellency and strong adhesion, it has problems in hardness and scratch resistance. The present invention has been made in order to solve such a problem, and is particularly excellent in hardness and abrasion resistance as compared with the conventional technology, and is further excellent in water repellency, stain resistance, abrasion resistance, and adhesion. An object of the present invention is to provide an agent and a method for forming a high-hardness water-repellent thin film using the same.

[0004]

The invention of claim 1 is a water-repellent coating agent containing an ultraviolet curable resin and a fluorine-based surface modifier. The invention according to claim 2 is the water-repellent coating agent according to claim 1, wherein the ultraviolet curable resin is an acrylic resin, a urethane resin, a silicone resin, or a resin containing them. The invention of claim 3 is
The water-repellent coating agent according to claim 2, wherein the acrylic resin is composed of a copolymer of acrylic acid and methacrylic acid. The invention according to claim 4 is that the fluorine-based surface modifier has a fluorinated alkyl group (Rf group) in which all or a part of the hydrogen portion is substituted with a fluorine atom, and a group compatible with the ultraviolet curable resin. The water-repellent coating agent according to any one of claims 1 to 3, which is a fluorine compound having in one molecule: The invention according to claim 5 is the water-repellent coating agent according to claim 4, wherein the fluorine compound is an organic polymer and the type is a random oligomer type. The invention of claim 6 is that the fluorine-based surface modifier is added in an amount of 0.1 to 100 parts by weight of the water-repellent coating agent.
The water-repellent coating agent according to any one of claims 1 to 5, which is contained in an amount of from 80 to 80 parts by weight. The invention according to claim 7 is the water-repellent coating agent according to claim 6, wherein the fluorine-based surface modifier is contained in an amount of 5 to 20 parts by weight based on 100 parts by weight of the water-repellent coating agent. The invention of claim 8 provides a step of coating the substrate with the water-repellent coating agent of any one of claims 1 to 7 to form an uncured layer, and a step of heating at a temperature of 150 ° C. or lower. And a step of polymerizing the uncured layer by irradiation with ultraviolet light.

[0005] The water-repellent coating agent of the present invention is characterized by containing an ultraviolet curable resin and a fluorine-based surface modifier. Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 (a) is a view for explaining an uncured layer after a substrate is coated with the water-repellent coating agent of the present invention, and FIG. 1 (b) shows a heat treatment of the uncured layer. FIG. 4 is a diagram for explaining a state of a thin film after ultraviolet irradiation. In FIG. 1, 1 is a substrate, 2 is a coating film, and 3 is a fluorine-based surface modifier.

In FIG. 1A, a coating film 2 of a water-repellent coating agent of the present invention immediately after being coated on a substrate 1 is in an uncured state containing an ultraviolet curable resin and a fluorine-based surface modifier. is there. The fluorine-based surface modifier 3 is in a state of being randomly dispersed in the coating film 2. Subsequently, by performing a heat treatment, as shown in FIG. 1 (b), the fluorine-based surface modifier 3 bleeds and orients so that the group containing a fluorine atom is directed toward the surface to form a surface layer. I do.

[0008] The heating temperature in this heat treatment is preferably 150 ° C or lower, usually about 60 to 120 ° C. According to this heat treatment temperature range, a bleed that provides good water repellency is obtained, and the curability of the ultraviolet curable resin is not adversely affected.

Subsequently, by irradiating the coating film 2 with ultraviolet rays, the coating film 2 is cured, and the high hardness water repellent thin film of the present invention is obtained. For the ultraviolet irradiation, any conventionally known means can be adopted, for example, a high-pressure mercury lamp or the like can be used.

The fluorine-based surface modifier used in the water-repellent coating agent of the present invention is a fluorinated alkyl group (R) in which all or a part of the hydrogen moiety is substituted with a fluorine atom.
It is preferable to use a fluorine compound having (f group) and a group compatible with the ultraviolet curable resin in one molecule. By using such a fluorine-based surface modifier, a fluorinated alkyl group bleeds into the surface layer by the above-mentioned heat treatment, and more favorable water repellency and stain resistance can be exhibited. In addition, by having a group compatible with the ultraviolet-curable resin in the molecule, layer separation from the ultraviolet-curable resin is eliminated, and high hardness and excellent wear resistance and abrasion resistance can be exhibited.

The fluorine compound is not particularly limited, and any commercially available fluorine compound can be used. For example, polyolefin, polyester,
Acrylic, silicone, epoxy, urethane-based resins, etc. were used as basic resins, and a fluorinated alkyl group (Rf group) and a group compatible with an ultraviolet-curable resin were provided in the molecule by a conventional method. Things. The polymer type may be, for example, any of a random oligomer type, a graft polymer type, a block copolymer type and the like. Among them, the random oligomer type is most preferable because it has an excellent balance between the resin compatibility and the molecular mobility, and the introduction of the Rf group and the resin compatible group can be relatively easily achieved by copolymerization.

The UV-curable resin used in the water-repellent coating agent of the present invention is not particularly limited, but is preferably an acrylic resin, a urethane resin, a silicone resin or a resin containing them. The selection of the UV-curable resin is made in consideration of the compatibility with the fluorine-based surface modifier and the like. Specific examples of suitable resins include acrylic resins such as copolymers of acrylic acid esters and methacrylic acid, and copolymers of glycidyl methacrylate and acrylic acid esters; polyurethane acrylates mainly composed of urethane, polyester polyols and methylene diisocyanate ( (MDI) based isocyanate combination, acrylic polyol and MDI, polyester polyol and tolylene diisocyanate (TDI) acrylic polyol and TDI, polyester polyol and hexamethylene diisocyanate (HMDI), acrylic polyol and HMDI, polyester polyol and isophorone diisocyanate (IPDI), Acrylic polyol and urethane resin such as IPDI; silicone-based silicone acrylate, methylphenyl And the like; a copolymer of recone and silicone acrylate, silicone resins such as a copolymer of methyl ethyl silicone and acrylate esters. Among them, a copolymer of acrylic acid and methacrylic acid is most preferable because it has low haze, good adhesion, and high film hardness.

The amount of the fluorine-based surface modifier can be appropriately changed depending on the required water repellency, hardness and the like of the coating thin film, but 0.1 to 80 parts by weight per 100 parts by weight of the water repellent coating agent. And more preferably 5 to 20 parts by weight. According to this range, good hardness and water repellency of the coating thin film can be obtained.

The substrate used in the present invention can be freely selected according to the purpose of use, but generally, glass or metal is used. In particular, when the substrate has a high hardness, a water-repellent thin film having higher hardness can be obtained.

The water-repellent coating agent of the present invention includes:
It goes without saying that various additives can be added as needed.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments of the present invention, but the present invention is not limited to only such embodiments.

Embodiment 1 Acrylic ultraviolet curable resin (for example, C1-86 manufactured by Dainippon Ink and Chemicals, Inc.)
0) 56 parts by weight, 0.3 part by weight of each of two kinds of phenone-based photopolymerization initiators (for example, Irgacure A and B manufactured by Ciba Geigy), and a fluorine-based surface modifier (for example, manufactured by Dainippon Ink and Chemicals, Inc.) (Defenser TR-220K)
Was added to obtain a water-repellent coating agent. At this time, the addition amount of the fluorine-based surface modifier is
The amount was changed between 0.05 and 100 parts by weight based on parts by weight. The water-repellent coating agent prepared as described above was coated on a glass substrate or brass to a thickness of about 2 μm, and dried at 80 ° C. for about 10 minutes. 80W to this
Irradiation was performed for about 20 seconds from a distance of about 10 cm with a high pressure mercury lamp having an output of / cm to form a high hardness water repellent thin film.
Film hardness of the high-hardness water-repellent thin film obtained as described above,
Water repellency, antifouling property, abrasion resistance, abrasion resistance and adhesion were measured and evaluated by the following methods.

The film hardness was evaluated by a scratch on the surface by a pencil scratch test according to JIS K5400. The water repellency was measured by measuring the contact angle of water of the coating film on the substrate with a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. If the contact angle was 100 ° or more, the water repellency was judged to be good. Antifouling property is 2 for magic ink (red, black), ballpoint pen, coffee, lipstick, etc.
After 4 hours of direct contact and wiping with water or ethanol, o was observed when no contamination was visually observed, △ when slight contamination was observed, and x when significant contamination was observed.
And The abrasion resistance and abrasion resistance were evaluated by rubbing the coating film on the substrate with a wiper (paper), and then evaluating the degree of scratching and changes in water repellency. The rubbing condition was a pressing load of 10 between the wiper and the substrate.
0gf, sliding speed 26.7mm / s, sliding 1000
0 times. The adhesion was evaluated by a peel test using an adhesive tape in five stages according to the degree of peeling. The state without peeling is 5 and good, the state with slight peeling is 4 and slightly good, and the state with slight peeling is 3 and usually 3
The state with considerable peeling was rated as 2 and slightly poor, and the state with full peeling was rated as 1 and poor.

The results are shown in Table 1 below. From Table 1, the fluorine-based surface modifier 5 to 100 parts by weight of the coating agent was used.
It can be seen that the best results are obtained when 20 parts by weight are added.

[0020]

[Table 1]

Embodiment 2 FIG. Embodiment 1 FIG. At
The ultraviolet-curable resin is prepared by copolymerizing (1) a copolymer with acrylic acid and methacrylic acid (for example, C1 manufactured by Dainippon Ink and Chemicals, Inc.).
-860), (2) a silicone-based silicone acrylate polymer (for example, X-
62-3509), (3) urethane acrylate polymer mainly composed of urethane (for example, GRANDIC FC-0612 manufactured by Dainippon Ink and Chemicals, Inc.), (4) bisphenol type epoxy resin (for example, having an average molecular weight of about 1800) ), (5) Silicone resin alone (for example, about 2200 average molecular weight). 10 parts by weight of a fluorine-based surface modifier (for example, Defensa TR-220K manufactured by Dainippon Ink and Chemicals, Inc.) was added to 100 parts by weight of the water-repellent coating agent to obtain a water-repellent coating agent.
Each characteristic of the obtained high hardness water repellent thin film is described in the first embodiment. The measurement was performed in the same manner as described above. Table 2 shows the evaluation results. Embodiment 2 Among them, the copolymer of acrylic acid and methacrylic acid was the best in terms of hardness.

[0022]

[Table 2]

Embodiment 3 FIG. Embodiment 1 FIG. At
(1) A random oligomer (for example, a defenser manufactured by Dainippon Ink and Chemicals, Inc.) is added to an acrylic ultraviolet curable resin (for example, C1-860 manufactured by Dainippon Ink and Chemicals, Inc.). (2) 10 parts by weight of a graft polymer (for example, Alon G manufactured by Toagosei Co., Ltd.) and (3) a block copolymer (for example, Modiper manufactured by NOF Corporation) were added to 100 parts by weight of the water-repellent coating agent. A water-repellent coating agent was used. Each characteristic of the obtained high hardness water repellent thin film is described in the first embodiment.
The measurement was performed in the same manner as described above. Table 3 shows the evaluation results.
Third Embodiment Among them, the random oligomer system was the best.

[0024]

[Table 3]

[0025]

The invention of claim 1 is a water-repellent coating agent containing an ultraviolet-curable resin and a fluorine-based surface modifier, and therefore has a particularly high hardness and abrasion resistance as compared with the prior art. It is possible to obtain a water-repellent coating agent excellent in water repellency, stain resistance, abrasion resistance and adhesion.

According to a second aspect of the present invention, the ultraviolet curable resin comprises:
Since it is an acrylic resin, a urethane resin, a silicone resin or a resin containing them, the hardness and the abrasion resistance are further excellent.

According to the third aspect of the present invention, since the acrylic resin is composed of a copolymer of acrylic acid and methacrylic acid, a low haze and a large film hardness can be obtained.

According to a fourth aspect of the present invention, the fluorine-based surface modifier can be compatible with a fluorinated alkyl group (Rf group) in which all or part of the hydrogen moiety has been replaced by a fluorine atom, and an ultraviolet curable resin. Since the compound is a fluorine compound having one or more groups in one molecule, layer separation from the ultraviolet-curable resin is eliminated, and high hardness and excellent abrasion resistance and abrasion resistance can be exhibited.

According to a fifth aspect of the present invention, since the fluorine compound is an organic polymer and the type thereof is a random oligomer type, the fluorine compound has an excellent balance between resin compatibility and molecular mobility, and the introduction of Rf group and resin compatible group. Can be relatively easily achieved by copolymerization, and can exhibit high hardness and excellent abrasion resistance and abrasion resistance.

The invention according to claim 6 is that the fluorine-based surface modifier is added in an amount of 0.1 to 100 parts by weight based on the water-repellent coating agent.
80 parts by weight, especially hardness, scratch resistance,
A water-repellent coating agent excellent in water repellency, stain resistance and abrasion resistance can be obtained.

According to a seventh aspect of the present invention, the fluorine-based surface modifier is used in an amount of 5 to 20 parts by weight per 100 parts by weight of the water-repellent coating agent.
Since it is contained by weight, a water-repellent coating agent having more excellent hardness, scratch resistance, water repellency, antifouling property and abrasion resistance can be obtained.

[0032] The invention of claim 8 provides a step of coating the substrate with the water-repellent coating agent according to any one of claims 1 to 7 to form an uncured layer;
Since the method for forming a high-hardness water-repellent thin film is characterized by having a step of heating at the following temperature and a step of polymerizing the uncured layer by irradiating ultraviolet rays, the hardness and the resistance are particularly high as compared with conventional techniques. Excellent scratch resistance, water repellency,
A thin film with excellent antifouling properties, abrasion resistance and adhesion can be obtained.

[Brief description of the drawings]

FIG. 1A is a view for explaining an uncured layer after a water-repellent coating agent of the present invention is coated on a substrate, and FIG. It is a figure for explaining the state of the thin film after irradiation.

[Explanation of symbols]

 1 Base material, 2 coating film, 3 fluorine surface modifier.

Claims (8)

[Claims] 1. A water-repellent coating agent comprising an ultraviolet-curable resin and a fluorine-based surface modifier. 2. The water-repellent coating agent according to claim 1, wherein the ultraviolet curable resin is an acrylic resin, a urethane resin, a silicone resin, or a resin containing them. 3. The water-repellent coating agent according to claim 2, wherein the acrylic resin comprises a copolymer of acrylic acid and methacrylic acid. 4. The fluorine-based surface modifier comprises a fluorinated alkyl group (Rf group) in which all or a part of a hydrogen portion is substituted by a fluorine atom, and a group compatible with the ultraviolet curable resin; The water-repellent coating agent according to any one of claims 1 to 3, which is a fluorine compound having in a molecule. 5. The water-repellent coating agent according to claim 4, wherein the fluorine compound is an organic polymer and the type is a random oligomer type. 6. The water-repellent coating agent according to claim 1, wherein the fluorine-based surface modifier is contained in an amount of 0.1 to 80 parts by weight based on 100 parts by weight of the water-repellent coating agent. . 7. The water-repellent coating agent according to claim 6, wherein the fluorine-based surface modifier is contained in an amount of 5 to 20 parts by weight based on 100 parts by weight of the water-repellent coating agent. 8. A step of coating the substrate with the water-repellent coating agent according to claim 1 to form an uncured layer, and heating the substrate at a temperature of 150 ° C. or lower. Polymerizing the uncured layer by irradiation with ultraviolet light.