JP6899743B2 - Snow and ice adhesion prevention method - Google Patents

Description

The present invention relates to a method for preventing snow and ice adhesion, and particularly to a method for preventing snow and ice adhesion, which is suitable for an existing LED traffic light or the like in a heavy snowfall area.

In recent years, transparent resin materials such as acrylic resin and polycarbonate resin, which are excellent in impact resistance and light weight, have been widely used as an alternative to transparent glass. Recently, these transparent resin materials have come to be used in outdoor applications such as lamp covers for road traffic lights, road signs, wall materials such as road sound insulation walls, terrace roofing materials, and glazing materials for aircraft or automobiles. ing.
In outdoor applications, especially in heavy snowfall areas, snow and ice adhere to transparent resin moldings such as lamp covers for sidewalk traffic lights and traffic signals or headlamp covers for automobiles. Can lead to a decrease in visibility, which can lead to traffic obstacles and eventually traffic accidents. Conventionally, incandescent lamps, halogen lamps, and other light sources that generate high heat have been used as light sources such as sideway traffic lights, traffic signals, headlamps of aircraft or automobiles, or tail lamps, but in recent years LEDs with low power consumption have been used to reduce costs. It is starting to switch to the light source. The LED light source leads to a reduction in power consumption, but since the amount of heat generated is lower than that of the conventional light source, there is a problem that when snow ice adheres to the surface of the LED light source protection molded body, the snow ice is difficult to melt and easily adheres. is there.

For some time, in order to prevent snow and ice from adhering to various devices and structures, paints that form a coating film with a snow-flowing surface where accumulated snow flows down have been developed, and for such applications. , Silicone resin, fluorine-containing components, and other materials that modify the surface of the coating film to make them water-repellent have been proposed.

In Patent Document 1, a mixture mainly composed of polymerizable acrylic group-containing polydimethylsiloxane and polymerizable polyester and / or polyether (meth) acrylate is applied to an object to be coated, and cured by electron beam irradiation to form a snow-sliding coating film. However, since electron beam irradiation is required, a device such as an irradiator is required when coating an object to be coated such as a signal that has already been installed, and the construction is simple. The problem arises that it is not.

On the other hand, as a material for imparting snow flow, the use of a material such as organosilicate that modifies the surface layer of the coating film to be hydrophilic has also been proposed.

For example, in Patent Document 2, by blending an acrylic resin-based paint with a combination of an organosilicate and a fluorine-based silane coupling agent, it is effective in preventing icing at low temperatures and improving snow flow performance at high temperatures. It is described that a composition capable of forming an excellent coating film can be obtained. However, since this composition contains an organic solvent, when applied to a resin base material such as polycarbonate or an object to be coated on which a coating film is formed, the composition to be coated contains an organic solvent at the time of coating. There was a problem that the coating film became turbid due to being soaked by the solvent. In addition, although the initial performance can be exhibited during snowfall, when the temperature rises after snowfall, the snow cover on the surface of structures such as traffic lights gradually changes to a solid snow-like state containing a large amount of water, but in the case of solid snow, it flows. In some cases, the snowiness decreased.

Further, Patent Document 3 discloses a composition containing an organosilicate and a surfactant having a perfluoroalkyl group, and the composition provides a coating film having excellent snow-flowing property even against solid snow. It is stated that it can be done. However, the hydrolyzed solution of organosilicate also requires an organic solvent, and especially when the object to be coated is made of resin, the object to be coated is invaded and transparent depending on the type of the organic solvent to be blended. And the snow flow property may decrease.

Japanese Unexamined Patent Publication No. 2007-332213 Japanese Unexamined Patent Publication No. 2003-147202 Japanese Unexamined Patent Publication No. 2002-206087

An object of the present invention is to provide a method for preventing snow and ice adhesion, which can be easily applied to an existing LED traffic light or the like and the obtained coating film is excellent in adhesiveness, transparency and snow flow property.

As a result of diligent studies on the above-mentioned problems, the present inventors have conducted a water-dispersible coating film-forming resin (A), an antifreeze agent (B), and a specific amount of fluorine on the surface of the object to be coated containing the transparent resin molded product. It has been found that the above object can be achieved by a method for preventing snow and ice adhesion, which comprises coating an aqueous clear coating composition containing the system surfactant (C) to form a coating film.

That is, the present invention relates to a method for preventing snow and ice adhesion, which includes the following aspects.
[Aspect 1]
A method for preventing snow and ice adhesion, which comprises coating a water-based clear coating composition on the surface of an object to be coated containing a transparent resin molded body to form a coating film, wherein the water-based clear coating composition is water-dispersible. The water-dispersible coating film-forming resin (A) contains the coating film-forming resin (A), the antifreeze agent (B), and the fluorine-based surfactant (C), and the content of the fluorine-based surfactant (C) is the water-dispersible coating film-forming resin (A). ), The method for preventing snow and ice adhesion, which is within the range of 0.1 to 10 parts by mass based on 100 parts by mass of the solid content.
[Aspect 2]
The method for preventing snow and ice adhesion according to aspect 1, wherein the water-dispersible coating film-forming resin (A) is an epoxy ester resin and / or an acrylic resin.
[Aspect 3]
The method for preventing snow and ice adhesion according to aspect 1 or 2, wherein the object to be coated is an object to be coated including a molded body for protecting an LED light source.
[Aspect 4]
The method for preventing snow and ice adhesion according to any one of aspects 1 to 3, wherein the object to be coated is an LED traffic light.
[Aspect 5]
The method for preventing snow and ice adhesion according to any one of aspects 1 to 3, wherein the object to be coated is an automobile headlamp.

According to the snow-ice adhesion prevention method of the present invention (hereinafter, may be abbreviated as "the present method"), since the water-based clear coating composition forms a coating film even at room temperature, an existing LED traffic light or an aircraft or automobile head It can be easily applied to an object to be coated including a transparent resin molded body such as a lamp. Further, since the coating film formed by the method of the present invention is excellent in transparency, there is no concern that visibility is deteriorated even if it is formed on the surface of the transparent resin molded product, and the finished appearance is excellent. Further, since the coating film formed by the method of the present invention has a property that the accumulated snow easily flows down, snow is accumulated on the LED traffic light on which the method is applied or the object to be coated such as the headlamp of an aircraft or an automobile. It is difficult, and it is possible to reduce the number of manual snow removal operations in heavy snowfall areas.
Further, the coating film formed by this method has good coating workability, is formed as a coating film uniform on the surface of the object to be coated, and has excellent adhesion to the object to be coated. Therefore, it is exposed outdoors for a long period of time. It is possible to develop sufficient snow flow even after it has been removed.

The method for preventing snow and ice adhesion of the present invention is a method for preventing snow and ice adhesion, which comprises applying a specific water-based clear coating composition to the surface of an object to be coated containing a transparent resin molded product to form a film.

The object to be coated to which this method is applied includes a transparent resin molded body, and even if the transparent resin molded body is a single body, it can be combined with a molded body or member formed of a plastic material or metal material other than the transparent resin. It may be configured. Examples of objects to be coated containing such a transparent resin molded body include lens covers and lamp covers using transparent resins such as polycarbonate resin and acrylic resin, road signs using transparent resin materials, and road sound insulation walls. Examples include wall materials, terrace roofing materials, glazing materials for aircraft or automobiles, and the like. Examples of suitable objects to be coated include those including a light source protection molded body such as a signal indicator lens cover, an aircraft or automobile headlamp cover, and a rear lamp cover.

Among them, an object to be coated containing a molded body for protecting an LED light source is preferable, and for example, an LED traffic light or the like can be preferably used.
The LED traffic light is not particularly limited as long as it is a traffic signal such as a traffic signal for roads and a traffic signal for railways. Examples of traffic signals for roads include traffic signals for vehicles, traffic signals for pedestrians, traffic signals for bicycles, and traffic signals for streetcars. The shape of the LED traffic light may be vertical or horizontal. For example, it may be composed of a signal lamp having only a red signal, a signal lamp having three colors of red, yellow, and green signals, or a signal lamp having two colors of red and blue, such as a signal lamp for pedestrians. Further, it may be either a new or existing traffic light, and is not particularly limited by the type of material, the type and presence / absence of a protective sheet or an old coating film, and the like.

Further, an LED-mounted display device for displaying road information such as an automobile-only road, for example, a road traffic sign equipped with an LED, an LED electric bulletin board, and the like are also preferably listed as objects to be coated including a molded body for protecting an LED light source. Can be done.
The water-based clear coating composition used in the present invention is particularly preferably used for an object to be coated containing an LED light source protection molded body having a calorific value lower than that of a conventional light source. Even when it is used for an object to be coated other than the object to be coated including, for example, a conventional traffic light, a road traffic sign, etc., it is possible to effectively prevent the adhesion of snow and ice.

Specific examples of the material of the object to be coated include, for example, steel plate, zinc plating, stainless steel, aluminum and the like as the metal material, and for example, polyethylene resin, polypropylene resin and acrylonitrile-butadiene-styrene as the plastic material. Examples thereof include resins such as (ABS) resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, and epoxy resin, and various plastic materials such as FRP. Among them, acrylic resin, which is a transparent resin, Various transparent resins such as polycarbonate resin, cyclic polyolefin resin, and polyethylene terephthalate resin are suitable, and acrylic resin or polycarbonate resin is most suitable from the viewpoint of weather resistance, impact resistance, and snow flow resistance for outdoor use. Further, a composite of these metal materials and plastic materials can also be mentioned as an object to be coated. Depending on these materials, the object to be coated may be subjected to degreasing treatment or surface treatment as appropriate.
The main body of the traffic light is made of aluminum or stainless steel, and the lens cover of the signal indicator is often made of transparent polycarbonate resin from the viewpoint of visibility, weather resistance and strength of the indicator. It is not limited to.
Further, before applying the method of the present invention, the substrate to be coated may be subjected to substrate adjustment such as cleaning or polishing, or an undercoat paint may be applied.

As a coating method for coating the water-based clear coating composition, for example, it can be coated by a known means such as spray coating, roller coating, brush coating, and sink coating. The number of coatings is not particularly limited, and the coating may be repeated once or a plurality of times. The dry film thickness varies depending on the condition of the object to be coated and the surrounding environment, but is generally in the range of 5 to 80 μm, preferably 8 to 70 μm.

As a drying method, normal temperature drying is adopted, and a coating film can be obtained by drying, but if necessary, heat drying may be used in combination. In normal temperature drying, a coating film can be obtained by drying in an environment of, for example, 5 to 45 ° C. The relative humidity (hereinafter sometimes abbreviated as RH) at the time of painting is preferably 70% or less, particularly 60% or less. The drying time for drying at room temperature is preferably 1 day or longer, more preferably 3 days or longer. When heat drying is used in combination, for example, a coating film can be obtained by drying in an environment of 30 to 100 ° C., preferably 35 to 90 ° C. for 5 to 120 minutes, preferably 10 to 100 minutes. The heat source may be sunlight.
Thus, a clear coating film is formed on the object to be coated.

The coating film in this method can have a dynamic contact angle of the coating film at the initial stage after coating of 60 ° or less, particularly 55 ° or less in terms of falling angle. If the dynamic contact angle of the coating film at the initial stage after coating exceeds 60 ° in the fall angle, it may be difficult for snow to flow down from the object to be coated such as the LED traffic light covered with the coating film. In the present specification, the initial coating film after coating includes, for example, a state in which a mild steel plate is coated with an applicator so that the dry film thickness is 50 μm, and dried at 20 ° C. for 7 days.

In the present specification, the fall angle at the dynamic contact angle is an inclination angle at which the water droplets start to slide when the water droplets are placed on the surface of the coating film in a horizontal state and gradually inclined. The static contact angle is the angle between the tangent line drawn on the surface of the edge of the water droplet and the surface of the coating film when the water droplet is placed on the surface of the coating film. The smaller this angle, the more hydrophilic the surface of the coating film is. Means.

<Aqueous clear paint composition>
A water-based clear coating composition applied to this method will be described.
The aqueous clear coating composition applied to this method contains a water-dispersible coating film-forming resin (A), an antifreeze agent (B) and a fluorine-based surfactant (C), and the fluorine-based surfactant (C). ) Is in the range of 0.1 to 10 parts by mass based on 100 parts by mass of the solid content of the water-dispersible coating film-forming resin (A).

The water-dispersible coating film-forming resin (A) is not particularly limited as long as it has a coating film-forming ability, and is a water-dispersible resin known per se, which has been conventionally used as a binder component for water-based paints. Can be used. "Water-based paint" is a well-known term in the art, and the content of water in the water-based clear paint composition applied to this method is 30 to 90% by mass, preferably 40 to 80% by mass, and further. It is preferably in the range of 50 to 70% by mass.
Specific examples of the resin of the water-dispersible coating film-forming resin (A) include acrylic resin, acrylic, silicone resin, urethane resin, fluororesin, epoxy resin, polyester resin, alkyd resin, melamine resin, and a mixture thereof. Examples of the resin or modified resin include an acrylic modified polyester resin, an acrylic silicone resin, an acrylic modified epoxy resin and an epoxy ester resin. In addition, these may be used alone or in combination of two or more.

As a method for preparing the water-dispersible coating film-forming resin (A), a conventionally known method such as emulsion polymerization, suspension polymerization, aqueous solution polymerization, or dispersion polymerization is used in the presence of an aqueous solvent or an organic solvent. Examples thereof include a method obtained by polymerizing the monomer and then dispersing it in water, if necessary. As a method for water dispersion of these water-dispersible coating film-forming resin (A), a conventionally known method can be used. For example, a method of neutralizing a part or all of anionic groups such as a carboxyl group contained in the resin with a basic compound such as amine and ionizing them to disperse them in water, or an aqueous medium containing the basic compound. It is possible to use a method such as adding the resin to the inside and dispersing the resin.

Among these resins having a coating film-forming ability, an aqueous dispersion of an epoxy ester resin and / or an acrylic resin is preferable from the viewpoint of snow flow, and in particular, the object to be coated is either a resin or a metal. However, an aqueous dispersion of an epoxy ester resin is preferable from the viewpoint of obtaining a coating film having excellent adhesion and snow flow.

A self-emulsifying type is suitable as the aqueous dispersion of the epoxy ester resin, and as a method for producing the epoxy ester resin, for example, an epoxy resin is reacted with a dibasic acid anhydride such as phthalic anhydride to esterify the epoxy ester resin. Examples thereof include a method of neutralizing the carboxyl group of the resin produced by the reaction and dispersing it in water. Further, the epoxy ester resin may be modified with a compound such as unsaturated and / or saturated fatty acid or rosin. As the epoxy ester resin, a commercially available product can be used, and examples of such a commercially available product include Watersol CD-550LAP, BM-1000P, EFD-5501P, EFD-5530, and EFD manufactured by DIC Corporation. -5560, EFD-5570, EFD-5580 (all trade names, Watersol series), and Arolon 5, 7, 27 (all trade names, Arolon series) manufactured by Nippon Catalyst Co., Ltd. can be mentioned.

Examples of the method for producing the aqueous dispersion of acrylic resin include a method of emulsion-polymerizing a polymerizable unsaturated monomer in the presence of water and a surfactant, and a copolymer obtained by copolymerizing a polymerizable unsaturated group-containing monomer. Examples include a method of water dispersion.

In the present invention, the average particle size of the aqueous dispersion of the water-dispersible coating film-forming resin (A) is 0 because the adhesion to the object to be coated and the falling angle after the freeze-thaw test are lower. It is preferably in the range of 1 μm exceeding .005 μm, more preferably in the range of 0.01 μm to 0.1 μm. Further, in the present specification, the average particle size is defined by diluting a sample with deionized water to a concentration suitable for measurement with a Coulter counter N4 (trade name, manufactured by Beckman Coulter Co., Ltd., particle size distribution measuring device). , The value measured at room temperature (about 20 ° C).
Here, in the present specification, the "water-soluble" resin has a different form from the above-mentioned "water-dispersed" resin, and when the resin is mixed with water, the resin is dissolved in water. It can be taken.

The aqueous clear coating composition applied to this method contains an antifreeze agent (B). The water-based clear coating composition applicable to the method of the present invention can form a coating film having excellent adhesion to an object to be coated and snow flow property by containing the antifreezing agent (B). The antifreezing agent (B) applied to this method is generally known as a freezing point depression agent, and freezing-point depression is a freezing point of a solvent when a solute is dissolved in a solvent (for example, water). Is a phenomenon in which is lowered. Examples of the antifreeze agent include C1-8 monoalkyl ethers of alkylene glycols or polyhydric alcohols, water-soluble liquid alcohols such as polyhydric alcohols, and the like.
Among these, from the viewpoint of the balance between the compatibility of the water-based clear paint composition and the coating film performance (transparency, adhesiveness, snow flow property and falling angle after freeze-thaw test are lower), water is used. It is easily soluble and has a boiling point of 170 ° C. or higher, preferably in the range of 180 to 300 ° C.
Here, "easily soluble in water" means that at room temperature (20 ° C.), it is miscible with distilled water at an arbitrary ratio without causing phase separation to form a transparent solution.
Examples of the antifreeze agent having a boiling point of 170 ° C. or higher, which is easily soluble in water, include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, triethylene glycol, diethylene glycol, and polyethylene glycol and polypropylene glycol having a molecular weight in the range of 200 to 600. Polyalkylene glycols such as: ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, polyethylene glycol monomethyl ether, tri. Glycol ethers such as propylene glycol monomethyl ether; glycol diethers such as triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether; diethylene glycol monoethyl ether acetate; ethyl diglycol, butyl diglycol, glycerin , Propionyl carbinol and the like.
Among these, at least one selected from ethylene glycol and propylene glycol is preferable.

The content of the antifreeze agent (B) is preferably 0.3 to 20 parts by mass, more preferably 1.5 to 15 parts by mass, based on 100 parts by mass of the solid content of the water-dispersible coating film-forming resin (A). It is preferably within the range of parts.
When an antifreeze agent (B) having a boiling point of 180 ° C. or higher, which is easily soluble in water, is used, the coating obtained is obtained by the synergistic effect of the water-dispersible coating film-forming resin (A) and the fluorine-based surfactant (C) described later. The film is excellent in transparency, snow flow, and rolling angle after freeze-thaw test.

The aqueous clear coating composition applied to the present invention contains a fluorine-based surfactant (C). Examples of the fluorine-based surfactant (C) include compounds having a hydrocarbon chain substituted with fluorine and a hydrophilic group. Examples of the hydrophilic group include an acid group such as a carboxyl group, a sulfonic acid group and a phosphoric acid group, and a group obtained by neutralizing these acid groups with a basic compound; a betaine structure such as carboxybetaine, sulfobetaine and phosphobetaine. Containing group: Polyoxyalkylene group such as polyoxyethylene group, polyoxypropylene group, polyoxyethylene (oxypropylene) group; hydroxyl group, amide; tertiary amino group, quaternary ammonium salt and the like.

Specifically, lithium salt, potassium salt, sodium salt, and ammonium salt of perfluoroalkyl sulfonic acid, potassium salt, sodium salt, and ammonium salt of perfluoroalkylcarboxylic acid, perfluoroalkyl dicarboxylic acid potassium salt, and perfluoroalkyl. Anionic fluorine-based surfactants such as phosphates; perfluorooctane sulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctane sulfonic acid amide, perfluoroalkylethylene oxide adduct, perfluoroalkylalkoxy Examples thereof include nonionic fluorine-based surfactants such as rates, which can be used alone or in combination of two or more. Some of the above-mentioned fluorine-based surfactants are, for example, "Mega Fuck" series (trade name, manufactured by DIC), "Surflon" series (trade name, manufactured by AGC Seimi Chemical Co., Ltd.), and "FC" series. It is commercially available as (trade name, manufactured by 3M), "Futergent" series (trade name, manufactured by Neos), and "Zonir" series (trade name, manufactured by DuPont).

In the present invention, the content of the fluorine-based surfactant (C) for exhibiting appropriate snow flow in the formed coating film is 100 parts by mass of the solid content of the water-dispersible coating film-forming resin (A). It is characterized in that it is in the range of 0.1 to 10 parts by mass, preferably 0.3 to 5.0 parts by mass, and particularly preferably 1.5 to 3.0 parts by mass. It is within the range. If it is less than this range, the snow flow property is insufficient, while if it is too much, the gloss of the coating film after drying is lowered and transparency cannot be obtained, which is not preferable.

Further, the aqueous clear coating composition applied to the present invention includes pigments (coloring pigments, extender pigments), organic metal compounds; silane coupling agents: the water, as long as the obtained coating performance (particularly transparency) is not impaired. Modification resins such as acrylic resins, fluororesins, urethane resins, and silicone resins other than the dispersible coating film-forming resin (A); organic solvents; reactive diluents; film-forming aids, catalysts, adhesion-imparting agents, sedimentation prevention Agents, antifoaming agents, rust preventives, antifungal agents, viscosity modifiers, dispersants, wetting agents, dehydrating agents, UV absorbers (eg benzotriazole-based absorbers, triazine-based absorbers, salicylic acid derivative-based absorbers, benzophenone Additives for paints such as system absorbers), light stabilizers (for example, hindered piperidines, etc.) and the like can be included.

Among the above additives for paints, the inclusion of a film-forming auxiliary may further improve the snow flow property. Examples of the film-forming auxiliary include compounds such as 2,2,4-trimethylpentanemonoisobutyrate and 3-methyl-3-methoxybutanol. When a film-forming auxiliary is blended, the content thereof is based on 100 parts by mass of the solid content of the water-dispersible coating film-forming resin (A) because the falling angle after the freeze-thaw test is lower. It is suitable that the amount is in the range of 1 to 30 parts by mass, preferably in the range of 2 to 20 parts by mass.

Among the above additives, when an oxidative curing resin is used as the water-dispersible coating film forming resin (A), the adhesion to the substrate and the snow flow property may be improved by containing the curing catalyst. is there. As the oxidative curing catalyst, a catalyst that promotes oxidative curing, specifically, a metal salt of a fatty acid, a metal oxide, a simple substance metal, or the like can be used. The fatty acids of the metal salts of fatty acids include octyl acid, naphthenic acid, neodecanoic acid, butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, soybean oil fatty acid, stearic acid, and tall oil. Examples include fatty acids. Examples of metal salts of fatty acids include salts of metals such as cobalt, manganese, zirconium, lithium, barium, zinc, copper, iron, calcium, magnesium, cerium, aluminum and strontium and fatty acids. These can be used alone or in combination of two or more.
As the curing catalyst, in addition to the metal salt of the fatty acid, one or more of the simple substances and oxides of the metals exemplified above can also be used. When the above curing catalyst is blended, the content of the active ingredient is 0 based on 100 parts by mass of the solid content of the water-dispersible coating film-forming resin (A) from the viewpoint of adhesion to the object to be coated and snow flow property. It is suitable to be in the range of 1 to 20 parts by mass, preferably 0.3 to 10 parts by mass.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples. In addition, "part" and "%" in the following example mean "part by mass" and "mass%" respectively.

Examples 1-8 and Comparative Examples 1-7
Paints (X-1) to (X-15) were produced with the compounding compositions shown in Table 1. (X-1) to (X-15) are all clear types. The numerical value in the table is the blending amount as a solid content.
Next, using the paints (X-1) to (X-15), test coating plates A to C were prepared by <Preparation of test coating plate> described later.
Using these test coating plates A to C, an evaluation test was conducted according to the test method and evaluation criteria described in <Evaluation test> described later. The obtained evaluation results are shown in Table 1.

(* 1) Water-dispersible coating film-forming resin (A-1): Acrylic resin aqueous dispersion (acrylic acid / 2-ethylhexyl acrylate / methyl methacrylate-based copolymer), resin solid content 46.5% by mass, average particles Diameter 0.125 μm.
(* 2) Water-dispersible coating film-forming resin (A-2): Self-emulsifying acrylic resin water dispersion (acrylic acid / i-butyl methacrylate / methyl methacrylate-based copolymer), resin solid content 46.5 mass %, Average particle size 0.075 μm,
(* 3) Water-dispersible coating film-forming resin (A-3): self-emulsifying epoxy ester resin water dispersion, oxidative curing resin, resin solid content 40% by mass, average particle size 0.31 μm,
(* 4) Water-dispersible coating film-forming resin (A-4): self-emulsifying epoxy ester resin water dispersion, oxidation-curable resin, resin solid content 40% by mass, average particle size 0.09 μm,
(* 5) Water-soluble coating film-forming resin (A'-5): Water-soluble epoxy ester resin, oxidation-curable resin, resin solid content 40% by mass, resin solution in a transparent state, average particle size with Coulter counter N4 Could not be measured.

(* 6) Solvent-based coating film-forming resin (A'-6): Solvent-type acrylic resin; in a reaction vessel equipped with a stirrer, thermometer, reflux cooler, and dropping device, "Swazole (trade name, Maruzen Petrochemical) 23 parts of "Industrial, aromatic hydrocarbon-based organic solvent)" was charged and stirred at 120 ° C. while blowing nitrogen gas, in which 23.0 parts of styrene, 17.7 parts of methyl methacrylate, and 2-ethylhexyl acrylate 10 were added. Mix the monomer composition of 0.0 part, i-butyl methacrylate 22.5 part, hydroxyethyl methacrylate 2.3 part, acrylic acid 0.8 part, and add 4 parts of tertiary butyl peroxide (polymerization initiator) to it. A mixed solution of 10 parts of swazole was added dropwise at a uniform rate over 3 hours, and the mixture was further aged at the same temperature for 2 hours. Then, it was aged for 1 hour after the completion of the dropping, and diluted with "Swazole 1000" until the solid content became 55% to obtain an organic solvent type acrylic resin (A'-6) solution. The weight average molecular weight of the obtained resin solid content was 50,000.

(* 7) Antifreeze agent (B-1): ethylene glycol, boiling point 197.3 ° C.
(* 8) Antifreeze agent (B-2): Propylene glycol, boiling point 188.2 ° C.
(* 9) Surfactant (C-1): Fluorosurfactant, perfluoroalkylethylene oxide adduct, solid content 100% by mass,
(* 10) Surfactant (C'-2): BYK-342, trade name, manufactured by Big Chemie Japan, solid content 53% by mass, silicone-based surfactant, polyether-modified polydimethylsiloxane,
(* 11) Film-forming auxiliary No. 1: Texanol, trade name, manufactured by Eastman Kodak, 2,2,4-trimethylpentane monoisobutyrate.

(* 12) Curing catalyst: DICNAME-3111TL, trade name, manufactured by DIC Corporation, solid content content 24% by mass (cobalt content 3% by mass),
(* 13) Thickener: Primal RM-2020NPR, trade name, manufactured by ROHM & Haas, urethane-associated thickener, solid content 20% by mass.
(* 14) Defoaming agent: SN deformer 1311, trade name, manufactured by San Nopco Ltd., silicone-based defoaming agent, solid content 100% by mass.
(* 15) Rust inhibitor: Sodium nitrite, also known as sodium nitrite.
(* 16) Antifungal agent: Biocut AF-40, trade name, manufactured by Nippon Soda Co., Ltd., solid content 42% by mass.
(* 17) Light stabilizer: HALS-TINUVIN292, trade name, manufactured by BASF, hindered amine-based light stabilizer, solid content 100% by mass.

<Preparation of test coating board>
Test coating plate A: A black vinyl chloride sheet coated with each aqueous clear coating composition (X-1) to (X-15) with an applicator so that the dry film thickness is 50 μm, and dried at 20 ° C. for 7 days. Was designated as a test coating plate A.
Test coating plate B: A mild steel plate coated with each paint (X-1) to (X-15) with an applicator so that the dry film thickness is 50 μm, and dried at 20 ° C. for 7 days is referred to as test coating plate B. did.
Test coating plate C: A polycarbonate resin plate coated with each of the aqueous clear coating compositions (X-1) to (X-15) with an applicator so that the dry film thickness is 50 μm, and dried at 20 ° C. for 7 days. Was designated as a test coating plate C.

<Evaluation test>
The test methods and evaluation criteria for each evaluation item are as follows.

(Test item 1.) Glossiness Each test coating plate A was measured at a measurement angle of 60 degrees using a gloss meter "micro-TRI-gloss" (trade name, gloss meter) manufactured by BYK.

(Test item 2.) Transparency The transparency of the coating film of each test coating plate C was visually evaluated.
◯: Transparent, good, and good visibility of the base.
Δ: Slightly turbid, slightly poor visibility of the base.
×: Very cloudy, poor visibility of the base.

(Test item 3.) Static contact angle (°)
10 μL of pure water was dropped onto each test coating plate A, and the contact angle 1 minute after the drop was measured at a measurement temperature of 20 ° C. by observing a monitor of model CA-X (Kyowa Interface Science Co., Ltd.). The values in the table are the average values when measured three times.

(Test item 4.) Fall angle (°)
20 μL of pure water was dropped onto each test coating plate A, and the angle of the coating plate when water droplets started to move when the coating plate was tilted at a measurement temperature of 20 ° C. was defined as the fall angle. For the measurement, a dynamic water contact angle measuring device "DSA-100 micro" (trade name, manufactured by KRUSS) was used. The lower the value of the fall angle, the better.

(Test item 5.) Fall angle after freeze-thaw test Each test coating plate A is exposed at -20 ° C for 16 hours, then exposed at 45 ° C for 8 hours for 10 cycles, and then falls. The angle was measured. The lower the value of the fall angle, the better.

(Test item 6.) Initial adhesion (iron plate)
According to JIS K 5600-5-6 (1990), 6 grid-like (grid-like) cross cuts that reach the substrate with a width of 5 mm from the coating film surface of each test coating plate B are inserted, and adhesive tape is placed on the surface. Was attached and rapidly peeled off, and then the peeled state of the cross-cut portion in the coating film was observed and evaluated according to the following criteria.
⊚: The edge of the cut is completely smooth, and there is no peeling on the eyes of any grid.
◯: Small peeling of the coating film at the intersection of the cuts, and the tape peeling area at the cross-cut portion is less than 5%.
Δ: The coating film is peeled off along the edge of the cut and / or at the intersection. The tape peeling area at the cross-cut portion is 5% or more and less than 60%.
X: The coating film is partially or wholly peeled off along the edge of the cut, and / or various parts of the eyes are partially or wholly peeled off. The tape peeling area at the cross-cut portion is clearly 60% or more.

(Test item 7.) Adhesion after water resistance test (iron plate)
After immersing each test coating plate B in warm water at 40 ° C. for 4 days and then washing with water, the adhesiveness of the test plates was evaluated. The adhesiveness test method and evaluation criteria were the same as those described in (Test item 6).

(Test item 8.) Initial adhesion (carbonate plate)
According to JIS K 5600-5-6 (1990), 6 grid-like (grid-like) cross-cuts that reach the substrate with a width of 5 mm from the coating film surface of each test coating plate C are inserted, and adhesive tape is placed on the surface. Was attached and rapidly peeled off, and then the peeled state of the cross-cut portion in the coating film was observed and evaluated. The evaluation criteria were the same as the method described in (Test item 6).

(Test item 9.) Adhesion after water resistance test (carbonate plate)
After immersing each test coating plate C in warm water at 40 ° C. for 4 days and then washing with water, the adhesiveness of the test plate was evaluated. The adhesiveness test method and evaluation criteria were the same as those described in (Test item 6).

(Test item 10.) Snow flow 1.
Immediately before winter, use a brush on the entire surface of the LED signal in Aomori City, Aomori Prefecture (main body; stainless steel with paint and lens cover (polycarbonate resin)) so that the dry film thickness after painting is 8 to 20 μm. , Each paint (X-1) to (X-15) is painted, dried at room temperature, painted for snow flow evaluation, and then left for 24 hours from the start of winter snowfall to observe the remaining snow condition on the surface of the traffic light. Then, visual evaluation was performed according to the following criteria.
5: No snow remains on the body or lens cover.
4: Both the main body and the lens cover have less than half of the surface of the LED traffic light covered with snow.
3: About half of the surface of the LED traffic light covered with snow is on both the main body and the lens cover.
2: Both the main body and the lens cover have more than half of the surface of the LED traffic light covered with snow, but some parts are not covered with snow.
1: The surface of the LED traffic light is entirely covered with snow.

(Test item 11.) Snow flow 2.
Immediately before winter, after cleaning the left and right headlamp covers (made of polycarbonate resin) of automobiles parked outdoors in Aomori City, Aomori Prefecture, the dry film thickness after painting is 8 to 20 μm using a brush on one side of the cover surface. After painting each paint (X-1) to (X-15), drying at room temperature, and painting for snow flow evaluation, leave it for 24 hours from the start of winter snowfall and leave it for the head of the car. The remaining snow condition on the surface of the lamp cover was observed, compared with the unpainted side, and visually evaluated according to the following criteria. During the test, all the headlamps of the car were turned off.
5: Compared to the unpainted side, there is no snow left on the lamp cover, which is good.
4: Compared to the unpainted side, the surface of the lamp cover is clearly covered with snow, and the remaining snow can be easily removed by running.
3: Compared to the unpainted side, the part where the surface of the lamp cover is covered with snow is about the same, but the remaining snow is removed by running.
2: Compared to the unpainted side, the surface of the lamp cover is about the same as the part covered with snow, and the remaining snow is slightly removed by running.
1: Compared to the unpainted side, there is no difference in the degree to which the surface of the lamp cover is covered with snow, and the remaining snow is not removed by running, and no effect is observed.

As can be understood from the evaluation results in Table 1, according to the present invention, a coating film having good workability and various performances such as adhesion to an object to be coated and snow flow property is formed, which is excellent. A method for preventing snow and ice adhesion can be provided.

Claims (5)

A method for preventing snow and ice adhesion, which comprises coating a water-based clear coating composition on the surface of an object to be coated containing a transparent resin molded body to form a coating film, wherein the water-based clear coating composition is water-dispersible. The water-dispersible coating film-forming resin (A) contains the coating film-forming resin (A), the antifreeze agent (B), and the fluorine-based surfactant (C), and the content of the fluorine-based surfactant (C) is the water-dispersible coating film-forming resin (A). ), The method for preventing snow and ice adhesion, which is within the range of 0.1 to 10 parts by mass based on 100 parts by mass of the solid content. The method for preventing snow and ice adhesion according to claim 1, wherein the water-dispersible coating film-forming resin (A) is an epoxy ester resin and / or an acrylic resin. The method for preventing snow and ice adhesion according to claim 1 or 2, wherein the object to be coated is an object to be coated including a molded body for protecting an LED light source. The method for preventing snow and ice adhesion according to any one of claims 1 to 3, wherein the object to be coated is an LED traffic light. The method for preventing snow and ice adhesion according to any one of claims 1 to 3, wherein the object to be coated is an automobile headlamp.