JPH07286121A - Color-variable laminated coating film - Google Patents

Abstract

PURPOSE:To provide a coating film excellent in weather resistance and color- changeability by successively laminating a color base coating film, a luminous pigment-containing coating film, a photochromic coating film and a clear coating film on a material to be coated. CONSTITUTION:This laminated coating film is obtained by forming A color base coating film 2 containing a coloring pigment on a material 1 to be coated and forming a coating film 3 containing a luminous pigment consisting of preferably a coherent mica pigment thereon and forming a photochromic substance consisting of preferably a spirooxazine-based compound and as necessary, a photochromic coating film 4 formed from an aqueous coating containing water- dispersible microcapsules containing a ultraviolet rays absorbing agent and having <=50mum average particle diameter thereon and further forming a clear coating film 5 thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color-variable laminated coating film obtained by laminating a photochromic coating film containing a photochromic substance and a coating film containing a glittering pigment containing a glittering pigment such as scale-like mica powder. .

[0002]

2. Description of the Related Art In recent years, various new coating materials and coating systems have been developed and studied with the diversification of coating appearance designs and the sophistication of appearance quality. The use of photochromic substances is being studied as one of the materials that can impart such a new coating appearance. The photochromic substance is a substance exhibiting a photochromic phenomenon in which the hue is changed by receiving light (ultraviolet light or visible light having a short wavelength) and the original color is restored in a dark place.

Japanese Unexamined Patent Publication (Kokai) No. 63-296871 discloses a two-layer coating film structure in which a top coat is formed on a base coat, and a laminated coating film in which an organic photochromic compound is contained in either the base coat or the top coat. ing. When such a coating film is irradiated with direct light such as direct sunlight, the color of the photochromic substance is changed to give different hues. When I return to the dark place again,
The hue returns to the original. By using the photochromic substance in this way, the hue can be reversibly changed.

However, photochromic materials are
There is a problem of poor weather resistance, and a coating film containing such a photochromic substance whose hue can change cannot be put to practical use.

In JP-A-3-250064, a color base coating film is provided on an object to be coated, and a photochromic coating film containing a photochromic substance, a mica base coating film containing mica, and a clear coating film are provided on the color base coating film. A sequentially formed laminated coating film is disclosed. In such a laminated coating film, since the mica base coating film is provided on the photochromic coating film, it is possible to reduce the amount of ultraviolet rays reaching the photochromic coating film, suppress deterioration of the photochromic substance, and improve weather resistance. Can be improved.

[0006]

However, in the structure of the laminated coating film in which the mica base coating film is provided on the photochromic coating film, the amount of ultraviolet rays reaching the photochromic coating film is reduced and the weather resistance of the photochromic substance is increased. However, since the amount of ultraviolet rays is reduced, the amount of change in color is reduced, and there is a problem that the change in color due to the photochromic phenomenon, which should be exhibited originally, cannot be sufficiently obtained. Further, since it is provided as an underlayer of the mica base coating film and is visually observed through the mica base coating film, there is a problem that the change in the color is not sufficiently expressed in appearance.

An object of the present invention is to solve such conventional problems and to provide a color-variable laminated coating film having excellent weather resistance and color variability.

[0008]

A color-variable laminated coating film of the present invention comprises a color base coating film containing a color pigment formed on an object to be coated, and a glitter containing a bright pigment formed on the color base coating film. And a photochromic coating film containing microcapsule particles containing a photochromic substance and formed on the bright pigment-containing coating film, and a clear coating film formed on the photochromic coating film.

In the present invention, the microcapsule particles contained in the photochromic coating film include a photochromic substance. Examples of the photochromic substance include azobenzenes, spiropyrans, spirooxazines, phenothiazines, phenazines, piantrons, anil, metal cytizonates, viologen, indigo, fulgide, tetrabenzopentanesene, stilbene and the like. Among these, photochromic substances of spirooxazines are preferable from the viewpoints of color development and decolorization speeds and repeated durability.

Further, the microcapsule particles can be formed by a chemical production method or a physical production method which has heretofore been generally known as an encapsulation method. As a chemical production method, an interfacial polymerization method, an in situ polymerization method, a liquid curing method, or the like can be adopted.

The interfacial polymerization method is a method in which a hydrophobic monomer and a hydrophilic monomer are used to perform encapsulation by an interfacial reaction, and examples thereof include an interfacial polycondensation method and an interfacial polyaddition method.

The interfacial polycondensation method is a method of forming a capsule wall of a polyester polymer or a polyamide polymer by a polycondensation reaction of a polyol such as polyamine, polyhydric alcohol or polyhydric phenol with a polybasic acid halide.

As the polyamine, ethylenediamine,
Diamines such as phenylenediamine, toluenediamine, hexamethylenediamine, diethylenetriamine,
Examples include triamines such as 1,3,5-benzenetriamine, 1,3,6-triaminonaphthalene and melamine, and polyfunctional amines such as polyethyleneimine and tetraethylenepentamine.

Examples of polyols include diols, triols, and polyfunctional alcohols. Examples of diols include ethylene glycol, neopentyl glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, and diethylene glycol. , Dipropylene glycol, triethylene glycol, hydrogenated bisphenol A, bisphenol dihydroxypropyl ether, hydroquinone, resorcinol and the like.

Examples of triols include glycerin, trimethylolethane and trimethylolpropane. Examples of polyfunctional alcohols include pentaerythritol, dipentaerythritol, tetrahydroxyanthracene, and phenol resins.

Examples of polybasic acid halides are difunctional acid chlorides such as azela oil chloride, adipoyl chloride, terephthaloyl chloride, cepacoyl chloride, dodecanediol acid chloride and benzenesulfonyl dichloride, benzene tetraside chloride, trimer. Examples thereof include polyfunctional acid chlorides such as zoyl chloride and benzenetrisulfonyl chloride.

The interfacial polyaddition method is a method of forming a capsule wall of polyurea polymer or polyurethane polymer by polyaddition reaction of polyamine or polyol with polyisocyanate, for example.

As the polyamine and polyalcohol,
Polyamines and polyalcohols such as those mentioned above can be used. Examples of polyisocyanates include difunctional isocyanates and polyfunctional isocyanates. Examples of difunctional isocyanates include aliphatic diisocyanates, aromatic diisocyanates, and aliphatic + aromatic diisocyanates.

Examples of the aliphatic diisocyanates include hexamethylene diisocyanate (HDI), lysine diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, 4,4'methylenebis (cyclohexyl isocyanate) (MDI), xylylene diisocyanate (XDI), and metaxylene. Examples thereof include diisocyanate (MXDI) and tetramethylxylylene diisocyanate (TMXDI).

Examples of aromatic diisocyanates include tolylene diisocyanate (TDI) and 4,4 'diphenylmethane diisocyanate. Examples of the aliphatic + aromatic diisocyanate include isophorone diisocyanate (IPDI).

Examples of the polyfunctional isocyanate include an aliphatic polyfunctional isocyanate which is a polymer of HDI, and an aromatic polyfunctional isocyanate which is a trimer of TDI.

The in situ polymerization method is a method in which a monomer or a polymerization catalyst is supplied from one of the inner phase and the outer phase of the core material to encapsulate the core material. Examples of the monomer used in the in situ polymerization method include isopropyl acrylate, butyl acrylate, hexyl acrylate, lauryl acrylate, acrylic acid, 2-hydroxyethyl acrylate,
Examples thereof include acrylic acid esters such as acrylamide, methacrylic acid esters such as methyl methacrylate, isobutyl methacrylate, hexyl methacrylate, methacrylic acid, 2-hydroxypropyl methacrylate and glycidyl methacrylate, and styrene, vinyl acetate and acrylonitrile. It is also possible to use a monomer having two or more polymerizable groups obtained by esterification of acrylic acid or methacrylic acid with a compound having two or more hydroxyl groups,
For example, glycol dimethacrylate, neopentyl glycol dimethacrylate, etc. are available.

The polymerization catalyst may, for example, be a peroxide or an azo compound. To give a specific example, for example,
Oily peroxides such as benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate; potassium persulfate,
Aqueous peroxides such as ammonium persulfate; oily azo such as azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile) Compounds: 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2
-Methylpropionamidine) and other aqueous azo compounds, etc., which are used alone or in combination of two or more.

The in-liquid curing method is a method in which a core substance is encapsulated in advance with a coating substance and then the coating is cured in a curing liquid. As the combination of the coating substance and the curing agent used in the submerged curing method, sodium alginate and calcium chloride or acid, polyvinyl alcohol and borax, polyvinyl alcohol and formalin or hydrochloric acid, gelatin and zirconium nitrate, ovalbumin and thermal coagulation (method) , Epoxy resin and boron tetrafluoride.

Examples of physical methods for producing microcapsule particles include a coacervation method and a submerged drying method. The coacervation method is a method in which a dissolved polymer is phase-separated as a concentrated phase on the surface of a core substance due to a change in environment to form a capsule wall film. For example, in an aqueous medium, by mixing gum arabic and gelatin to adjust the pH of the solution, the dissolution or precipitation can be controlled and the formation of the capsule wall film can be controlled. In a non-aqueous system, a solution can be controlled by preparing a solution in a good solvent in which a polymer is dissolved and gradually adding a non-solvent in which the polymer is not dissolved therein to adjust the polarity of the medium. For example, polystyrene coacervation can be performed by adding ethanol to a benzene solution of polystyrene.

The in-liquid drying method is a method of dispersing a wall membrane substance solution in which a core substance is emulsified or dispersed in water or a non-aqueous medium,
After that, the solvent that dissolves the wall film substance is removed by stirring, heating, and / or depressurization to form a capsule wall film.

Further, when the photochromic coating film is formed from an aqueous paint, the microcapsule particles are preferably water dispersible. In order to impart such water dispersibility to the microcapsule particles, it is preferable to use a hydrophilic polymer as the wall material of the microcapsule particles. When such a hydrophilic polymer wall material is formed by the coacervation method, it is formed by coacervating a concentrated solution phase of the polymer from an aqueous solution of the water-soluble polymer and crosslinking the water-soluble polymer with a curing agent. be able to.

In the case of producing microcapsule particles by the coacervousin method, for example, first, a solution of a photochromic substance is mixed with an aqueous solution of a water-soluble polymer and emulsified, and then the pH is adjusted, diluted with water, or salt or alcohol is added. It can be produced by causing coacervation and then adding a water-soluble polymer curing agent to crosslink the wall material of the microcapsule particles.

The water-soluble polymer that constitutes the wall material of the microcapsule particles is not particularly limited as long as it is a water-soluble polymer that can be made water-insoluble by a curing agent, but a gelatin-based polymer is particularly preferable. , A gelatin-arabic gum polymer, a gelatin-carboxymethyl cellulose polymer, and the like can be used. These polymers can be water-insolubilized with aldehydes such as glutaraldehyde, diketones, epoxides, acid anhydrides, acid chlorides, carbodiimides, and inorganic salts.

In the present invention, the photochromic substance may be incorporated into the microcapsules in a solution state. In this case, an ultraviolet absorber, an antioxidant, a hindered amine stabilizer, etc. can be dissolved and contained in the solution.

As the ultraviolet absorber, 2-hydroxy-
Benzophenone derivatives such as 4-methyloxybenzophenone, benzotriazole derivatives such as 2- (2'-hydroxy-5'-methylphenol) -benzotriazole, 2,4-di-t-butylphenyl-3 ', 5'- Di-t-butyl-4'-hydroxybenzoate, 2-
(2-hydroxy-3,5-di-t-aminophenol) -2H-benzotriazole, 2- (2-hydroxy-3,5-di (1,1-dimethylbenzyl) phenyl) -2H-benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2
A benzotriazole-based compound such as-(2-hydroxy-5-methylphenyl) -2H-benzotriazole;
Benzophenone-based compounds such as 2-hydroxy-4-dodecyloxy-benzophenone; N- (2-ethylphenol) -N- (2-ethoxy-5-t-butylphenylanilic acid anilide such as anilides; ethyl; Examples of cyanophenyl acrylate compounds such as 2-cyano-3,3-diphenyl acrylate may be used alone or in combination of two or more. For example, products marketed by Ciba Geigy under the trade names of "Tinubin 328" and "Tinubin 900", and "Seesorb 70" from Cypro Kasei.
Commercially available products under the trade names of "1" and "Seesorb 704" can be used. As the ultraviolet absorber of a benzophenone-based compound, for example, one commercially available from Cipro Kasei Co. under the trade name of “Seesorb 103” can be used.

As described above, it is preferable to appropriately select the ultraviolet absorber contained in the capsule in consideration of the compatibility with the photochromic material.

Examples of the antioxidant include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-t). -Butyl-4-hydroxyphenyl) propionate and other hindered phenolic compounds: 2- (3,5-t-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid bis (1,
Hindered amine compounds such as 2,2,6,6-pentamethyl-4-piperidyl and bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate: pentaerythritol tetrakis (β-lauryl thiopropionate) ) And other sulfur-containing antioxidants, etc., which may be used alone or in combination of two or more. Antioxidants of hindered phenolic compounds,
For example, from Ciba Geigy "Irganox 10
Commercially available products under the trade names of "10" and "Irganox 1076" can be used. Examples of antioxidants for hindered amine compounds include those marketed by Ciba-Geigy under the trade names of "Tinuvin 144" and "Tinuvin 123", and "Sanol LS-440" and "Sanol LS" from Sankyosha. What is marketed by the brand name of "-292" can be used. As the sulfur-containing antioxidant, for example, "SEE
What is marketed under the brand name "NOX 412S" can be used.

The antioxidant added to such a capsule is also preferably selected in consideration of the compatibility with the photochromic material.

The average particle size of the microcapsule particles used in the present invention is preferably 50 μm or less, more preferably 10 μm or less. If the average particle size is too large, it becomes thicker than the thickness of the coating film, which is not preferable as a material to be blended in the coating material.

As the glittering pigment contained in the glittering pigment-containing coating in the present invention, an aluminum pigment as used in metallic paints, scale-like mica powder and the like can be used. As the scale-like mica powder, titanium oxide is coated on the surface so as to exhibit pearl luster, so-called white mica and interfering mica, and titanium oxide and iron oxide are coated, so-called colored mica, etc. Can be used. The pearlescent luster of the flake-like mica powder is said to occur because it transmits and reflects part of the light in the coated titanium oxide layer and also produces coherent light. Therefore, when using the scale-like mica powder as the bright pigment in the present invention, a variety of light with incident light and reflected light in the vicinity of such a scale-like mica powder-containing layer and a microcapsule particle-containing layer having photochromic properties. Such interactions allow a higher degree of multicolored color development.

As the binder of the bright pigment-containing coating film and the photochromic coating film of the present invention, those generally known as film-forming polymers can be used. Examples of the film-forming polymer include acrylic resin, alkyd resin, polyester resin, polyurethane resin and amino resin. As a curing agent, for example, an alkoxymethylol melamine resin, an isocyanate compound or a block isocyanate compound, a polyanhydride,
There are polyepoxy compounds and the like. Solvents that dissolve or disperse the above polymers and curing agents are also used for paints, and for example, toluene, xylene, butyl acetate, methyl acetate, methyl isobutyl ketone, butyl alcohol, aliphatic hydrocarbons, aromatic hydrocarbons, etc. are used. To be done. Water may be used as the solvent-free system and is not particularly limited.

When an aqueous binder is used as the binder for the bright pigment-containing coating film and the photochromic coating film, for example, acrylic resin, amide group-containing acrylic resin obtained by copolymerizing amide group-containing monomer, acrylic / acrylic
Cellulose acetate butyrate mixed resin, epoxy resin, alkyd resin, nitrocellulose, polyurethane resin, polyamide resin, epoxy modified alkyd resin and the like can be used. These resins can be used alone or in combination with a curing agent such as a melamine resin, a urea resin, an isocyanate compound or a blocked isocyanate compound. The binder resin may be any type of resin that is dried at room temperature or baked.

In the coating film containing a bright pigment, the content of the bright pigment is preferably 0.1 to 40% by weight, and more preferably 0.1 to 15% by weight based on the solid content of the coating material. In the photochromic coating film, the content of the microcapsule particles is preferably 1 to 95% by weight, more preferably 20 to 70% by weight based on the solid content of the coating material.

As the color base coating film in the present invention, a color base coating film which has been conventionally used for a laminated coating film for automobiles can be used as long as it is a coating film containing a coloring pigment.

As the clear coating film in the present invention, for example, a clear coating film which has been conventionally used for laminated coating films for automobiles can be used, and a thermosetting or thermoplastic acrylic coating film or the like is used. You can

[0042]

In the present invention, a coating film containing microcapsule particles containing a photochromic substance is used as the photochromic coating film. Although the details of the reason why the photochromic substance contained in such a microcapsule wall exhibits excellent weatherability are not clear, it is likely that the photochromic substance is shielded from the outside by the microcapsule wall so that it is affected by oxygen and the like. Difficulty and weather resistance is expected to improve.

Further, in the present invention, as described above,
It is preferable to include an ultraviolet absorber and the like in the microcapsule particles. When the ultraviolet absorber and the like are contained together, it is preferable to use a substance having an absorption wavelength that does not affect the color variability of the photochromic substance. Further, the weather resistance can be further improved by incorporating an ultraviolet absorber or the like into the photochromic coating film and / or the clear coating film.

In the present invention, since the weather resistance of the photochromic coating film is improved as described above, the photochromic coating film can be provided on the bright pigment-containing coating film. Therefore, unlike the conventional case, the amount of ultraviolet rays or the like that discolor the photochromic substance is not reduced by the coating film containing the bright pigment, and the discoloring property originally possessed by the photochromic substance can be sufficiently exhibited. In addition, since the light transmitted through the photochromic coating enters the coating containing the bright pigment, light is likely to be multiplexed due to the interaction between the photochromic substance and the bright pigment. Therefore, it is possible to generate a color of a more highly multiplexed color than ever before. In particular, when scale-like mica powder is used as the bright pigment, such interaction is easily realized.

[0045]

[Examples] Hereinafter, the compounding amounts in the paint are all based on the nonvolatile solid content of the paint.

Example 1 A laminated coating film as shown in FIG. 1 was formed. The laminated coating film shown in FIG. 1 has a structure in which a color base coating film 2, a mica-containing coating film 3 as a bright pigment-containing coating film, a photochromic coating film 4, and a clear coating film 5 are laminated on an article 1 to be coated. have.

As the article to be coated 1, an electrodeposition coating film is formed on a metal plate, and an intermediate coating film (trade name "Olga P-2 Light Gray", Nippon Paint Co., Ltd.) is formed on the electrodeposition coating film. (Manufactured) was applied with a film thickness of 35 μm and baked at 140 ° C. for 20 minutes. A color base paint (trade name “Olga P-2 White”, manufactured by Nippon Paint Co., Ltd.) was applied on the intermediate coating film of the article 1 to a thickness of 35 μm, and 140
A color base coating film 2 was formed by baking at 20 ° C. for 20 minutes.

On the color base coating film 2, scale-like mica powder (white mica, trade name "Iriodin 103W"
II ", manufactured by Merck & Co., Inc.) and 3% by weight of water-based paint (trade name" Supernix M-230 ", manufactured by Nippon Paint Co., Ltd.) are coated to a film thickness of 12 µm, and the temperature is 60 ° C.
It was pre-dried for 5 minutes. An aqueous dispersion of microcapsule particles containing a spironaphthoxazine-based photochromic compound (trade name "PC-
7 ", manufactured by Mitsubishi Kasei Co., Ltd., as a spironaphthoxazine-based photochromic compound in an amount of 10% by weight (trade name:" Supernix M-23 ").
0 ", manufactured by Nippon Paint Co., Ltd.) to a film thickness of 12 μm, and pre-dried at 60 ° C. for 5 minutes.

On the obtained photochromic coating film 4,
An oil-based clear coating (trade name “Superlac O-150 Clear”, manufactured by Nippon Paint Co., Ltd.) was applied to a film thickness of 35 μm, and after coating, it was baked at 140 ° C. for 2 minutes. By this baking, the mica-containing coating 3, the photochromic coating 4, and the clear coating 5 were baked.

Example 2 In the coating material for forming the photochromic coating film 4 and the clear coating film 5, an ultraviolet absorber (trade name "Sumisorb 1" was used.
00 ", manufactured by Sumitomo Chemical Co., Ltd.) was added in the same manner as in Example 1 to form a laminated coating film as shown in FIG.

Comparative Example 1 As a photochromic material to be contained in the photochromic coating film 4, spironaphthoxazine-based photochromic compound itself was used instead of the microcapsule particles.
Example 1 above, except that it was added directly to give a weight percent.
A laminated coating film as shown in FIG. 1 was formed in the same manner as in.

Comparative Example 2 In Comparative Example 1, the stacking order of the mica-containing coating film 3 and the photochromic coating film 4 was changed, and the photochromic coating film 4 was formed on the color base coating film 2 as shown in FIG. A laminated coating film was formed in the same manner as in Comparative Example 1 except that the mica-containing coating film 3 was formed on the coating film 4.

The laminated coating films of Examples 1 and 2 and Comparative Examples 1 and 2 obtained as described above were evaluated for weather resistance and discoloration property as follows.

The weather resistance sunshine carbon weather meter was used to measure the total irradiation time until the reversibility of the hue change of the sample coating film disappeared, and the results are shown in Table 1.

[0055] & discoloration fine day, visually hue change of the coating film under the sunlight, were evaluated by the following evaluation methods. ◯: The hue is remarkably changed. Δ: A slight change in hue is seen. X: Almost no change in hue is observed. The results obtained are shown in Table 1.

[0056]

[Table 1]

As is apparent from Table 1, the laminated coating films of Examples 1 and 2 according to the present invention are excellent in weather resistance and discoloration. In particular, Example 2 in which the photochromic coating film and the clear coating film contained an ultraviolet absorber exhibited excellent weather resistance as compared with Example 1.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a laminated coating film of an example according to the present invention.

FIG. 2 is a sectional view showing an example of a conventional laminated coating film.

[Explanation of symbols]

 1 ... Substrate 2 ... Color base coating 3 ... Mica-containing coating 4 ... Photochromic coating 5 ... Clear coating

Claims (7)

[Claims] 1. A color base coating film containing a color pigment formed on an object to be coated, a glittering pigment-containing coating film containing a glittering pigment formed on the color base coating film, and the glittering pigment-containing coating film. A color-variable laminated coating film comprising a photochromic coating film formed on a film and containing water-dispersible microcapsule particles containing a photochromic substance, and a clear coating film formed on the photochromic coating film. 2. The color-variable laminated coating film according to claim 1, wherein the microcapsule particles are water-dispersible and the photochromic coating film is formed of an aqueous paint. 3. The color-variable laminated coating film according to claim 1, wherein the photochromic substance is a spirooxazine-based compound. 4. The color-variable laminated coating film according to claim 4, wherein the solution contains an ultraviolet absorber. 5. The color-variable laminated coating film according to claim 1, wherein the microcapsule particles have an average particle diameter of 50 μm or less. 6. The color-variable laminated coating film according to claim 1, wherein the bright pigment is scale-like mica powder. 7. The color-variable laminated coating film according to claim 7, wherein the flaky mica powder is an interference mica pigment.