JPH0541006Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to metal products that are sensitive to temperature changes and have the ability to reversibly change color. Metal products with extremely high added value as color effect products by using granules to form a permanent thermochromic coating film with high color density, sharp color development ← → color erasing function, on metal surfaces. The aim is to provide the following. [Prior Art] In recent years, various thermochromic substances have been developed. In particular, electron-donating color-forming dyes with excellent coloring power can be used in combination with electron acceptors and solvents to produce pressure-sensitive copying paper and copies. Knowledge has been disclosed that it is effective as a desensitizer, and furthermore, for example, in U.S. Pat. The fact that colors can be reversibly changed and faded has been disclosed, and the unique color change behavior using this mixture is
Today, it is widely used in toys such as dolls and stuffed animals, daily necessities such as cups and buckets, clothing such as towels and T-shirts, and products such as ceramics, glass, and stickers. Therefore, attempts to use such compositions to obtain metals whose colors change reversibly due to temperature changes have been a challenge in the industry, in view of the expected great industrial applicability of such products. It has become a focus of interest. [Problems to be solved by the invention] However, the thermochromic material, which is a mixture of the three components, exhibits its thermochromic function only when the three components are in a strictly fixed ratio system.
When these three components are mixed into a paint consisting of an adhesive, etc., the solvent, plasticizer, emulsifier, etc. contained in the paint may enter the three-component coexistence system, or some of these three components may be leached out of the system. , it flows out due to evaporation, etc., and the initial constant ratio system of the three-component mixture is easily destroyed, so that it hardly exhibits an effective thermochromic function without the need for heat treatment during production. Therefore, recently, granules in which the three-component mixture is encapsulated by a known microencapsulation method have been used, but even in this case, the capsule surface tends to become a porous film and the strength is insufficient. Paints mixed with objects and adhesives are better than those in which the three components are mixed directly into the paint, but some of the three components may leak out of the system during the heat treatment process to fix them to the metal surface. The current situation is that solvents, plasticizers, emulsifiers, etc. in paints enter the three-component mixture system, resulting in a significant decline in color change function. Therefore, so far only products that are difficult to commercialize or have little commercial value have been obtained. [Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned drawbacks, the inventors of the present invention have added a concealing layer 4 to the surface of the metal 1.
Then, on the concealing layer 4, a granular material in which a composition consisting of three components, an acid color developing substance, an acidic substance, and a solvent is encapsulated in microcapsules in a thermosetting resin, is further coated with a highly hydrophilic resin. A thermosetting resin or a thermosetting resin and a thermoplastic resin and/or an alkyd resin, that is, a thermosetting resin alone, a thermosetting resin, and a thermoplastic resin, are added to the thermochromic granular material whose surface is coated with a molecular compound. The discoloration layer 2 is formed with a paint made by blending any one of the following four types: both of the above, both a thermosetting resin and an alkyd resin, and a thermosetting resin, a thermoplastic resin, and an alkyd resin. Conventionally, thermoplastic color-changing metals are provided with a transparent glossy layer 3 on the surface of the color-changing layer 2 using a paint made of a thermosetting resin or a thermosetting resin, a thermoplastic resin, and/or an alkyd resin. He found a way to solve all of the problems and completed this invention. [Function] By encapsulating a 3-component mixture of an acid developer, an acidic substance, and a solvent in microcapsules with a thermosetting resin, the surface of the granular material is further coated with a hydrophilic polymer compound. The film of the encapsulated granules becomes tougher, significantly improving heat resistance and solvent resistance, and the three encapsulated components are completely encapsulated within the capsule, making it suitable for heat treatment when forming a color-changing coating on metal surfaces. The fixed ratio system of the three components is completely preserved, and the color density is high.
Permanently exhibits sensitive thermochromic function. In addition, the thermosetting resin, thermosetting resin, thermoplastic resin, and/or alkyd resin that is blended into the paint firmly fixes the thermochromic granules, resulting in excellent durability and increased commercial value. Highly thermoreversible color-changing metals can be obtained. [Example] Examples of acid developing substances constituting the thermochromic granules used in the present invention include 3,3' dimethoxyfluorane (yellow), 3-chloro-6-phenylaminofluorane (yellow), orange), 3-diethyl-7,8
-Benzofluorane (peach), 3,3′,3″・(p-diethylaminophenyl)phthalide (purple blue), 3,
Substituted phenylmethane or fluoran derivatives such as 3'bis(p-dimethylaminophenyl)phthalide (green), 3-diethylamino-6-methyl-7-phenylaminofluorane (black), various indolylphthalide dyes , or spiropyrans. From these, dyes of any hue can be easily obtained as colorants for temperature-sensitive and pressure-sensitive dyes, and in the present invention, these may be used alone or in combination of two or more. Examples of the acidic substance that develops color by combining with the acid color developing substance include phenols such as p-phenylphenol, bisphenol A, cresol, resorcinol, chloroglycine, phenolic resin oligomer, β-naphthol, etc. metal or ammonium salts, 5-
benzotriazoles such as chlorbenzotriazole, 4-laurylaminosulfobenzotriazole, 5-butylbenzotriazole, dibenzotriazole, 2-oxybenzotriazole, 5-carboethoxybenzotriazole, etc., or metal salts or ammonium salts thereof;
Further examples include organic acids such as resorcinic acid, gallic acid, benzoic acid, pyromellitic acid, stearic acid, p-toluenesulfonic acid, 1,5-naphthalenedisulfonic acid, and substituted derivatives or metal salts thereof. May be used alone, 2
More than one species may be used in combination. In the present invention, 1,2,3-triazoles are the most effective among these. Examples of solvents that can dissolve and coexist with the acid developer and the acidic substance include alcohols such as octyl alcohol, dodecyl alcohol, myristyl alcohol, and oleyl alcohol, and esters such as lauryl stearate, lanolin, and glyceride palmitate. azomethines such as benzylideneaniline, benzylidene stearylamine, benzylidene phenylhydrazine, 1,4-bisphenylazomethine, amides such as acetamide, lauric acid amide, p-toluenesulfuramide, salicylic acid amide, etc. Examples include rice oil, tallow, naphthalene, and bark oil. These solvents are thought to reversibly repeat color development and decolorization by bonding with acid color developing substances and acidic substances near their melting points. Specific examples of compositions comprising the above three components used in the present invention are shown in Table 1. In Table 1, CVL is a triphenylmethane-based blue pressure-sensitive/thermal copying dye manufactured by Hodogaya Chemical Co., Ltd., and PSD/HR is a fluoran-based red pressure-sensitive/thermal copying dye manufactured by Nippon Soka Chemical Co., Ltd. Pigments for paper, erasing (discoloration)
Temperature means the temperature at which the color disappears above the indicated temperature and the color develops into blue, green, red, etc. at a temperature below that temperature.

[Table] The above 3-component mixture includes, for example, one or more of unsaturated polyester resin, polyurethane resin, melamine resin, benzoguanamine resin, epoxy resin, phenolic resin, and urea resin.
After coexistence and encapsulation using known encapsulation methods such as interfacial polymerization and in-situ polymerization, the encapsulation body is further suspended in water to form hydrophilic polymer compounds such as polyvinyl alcohol, polyacrylate, By further coating the surface of the inclusion body with gelatin, methylcellulose, alginic acid, etc.
Thermochromic granules are obtained. The obtained granules are made of a thermosetting resin similar to the above, or a monomer having a functional group such as methylacrylamide or its etherified product, alkyl hydroxymethacrylate, acrylic acid or methacrylic acid, glycidyl methacrylate, and acrylic acid. Thermosetting acrylic alone, which is a copolymer with monomers such as esters, methacrylic esters, and styrene, or thermoplastic resins such as halogenated olefin resins, polyacrylic ester resins, saturated polyester resins, polyamide resins, fatty acid vinyl resins and/or condensates of polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol with polybasic acids such as phthalic anhydride, maleic anhydride, and sebacic acid, and oils such as linseed oil, soybean oil, and castor oil. Alternatively, alkyd resins modified with fatty acids such as palmitic acid, stearic acid, and oleic acid, or the above condensates modified with rosin esters, phenol resins, epoxy resins, styrene resins, and acrylic resins are used, and these solvent solutions are used. Copper, zinc, aluminum, galvanized iron,
After spraying, brushing, crushing, or directly printing on metal surfaces such as stainless steel
By heat treatment at 100-200℃ for 5-60 minutes,
The excellent thermoreversible color-changing metals of the present invention can be obtained. Furthermore, by adding an anti-sagging agent such as an aluminum silicate type, silicon oxide type, or synthetic fatty acid ester polymer to the paint of the present invention, it is possible to eliminate sagging of the coating film on an inclined surface. Also, by adding ordinary pigments that are permanent colors, it is possible to reversibly change one color to another. In addition, the surface of the metal 1 and the discoloration layer 2 of the present invention
By forming the concealing layer 4 in between, the color change of the discoloration layer 2 can be made even more sharp. In this case, the hiding material is titanium oxide, zinc white,
Calcium carbonate, barium sulfate, aluminum silicate, etc. may be used, and the same resin as used in the discoloration layer 2 is used as the fixing agent. Furthermore, by forming the transparent glossy layer 3 on the surface of the color-changing layer 2 of the present invention using the above-mentioned thermosetting resin or a paint made of a thermosetting resin, a thermoplastic resin, and/or an alkyd resin, the color-changing layer 2 can be further enhanced. In addition to being even stronger, the surface gloss is significantly improved and the penetration of ultraviolet rays into the color-changing layer 2 is blocked, so the durability of the thermochromic function can be greatly increased. In addition, the above granules and each paint contain conventional agents such as extender pigments, surfactants, plasticizers, ultraviolet absorbers, antioxidants, desiccants, wetting agents, penetrants, suspending agents, and color components. Anti-skinning agent, anti-skinning agent,
Even if a flame retardant, an antifoaming agent, a leveling agent, a coupling agent, an antistatic agent, etc. are added, it does not depart from the gist of the present invention. Next, a concrete example of the present invention will be shown. (Example 1) As shown in the enlarged cross-sectional view of Fig. 1, 50 parts by weight of Dial SE-5248 (thermosetting acrylic resin solution, manufactured by Mitsubishi Rayon Co., Ltd.) (the following) was applied to the surface of the zinc miniature car body metal 1 treated with zinc phosphate. , parts by weight are abbreviated as parts), 20 parts of titanium oxide, homogenol L-100
(Surfactant, Kao Atlas Co., Ltd.) 0.3 parts, xylene 15 parts, ethylene glycol monobutyl ether
A paint consisting of 15 parts was applied by an electrostatic coating method using a spray gun, and heat treated at 150° C. for 10 minutes to form a white concealing layer 4. Next is Dianar
SE-5248 40 copies, Super Betsucomin G-821-
60 (melamine resin, manufactured by Dainippon Ink Co., Ltd.) 10 parts, Kuromitsu Color S-17 Vermilion (thermoreversible color changing granules, manufactured by Matsui Shiki Kagaku Kogyo Co., Ltd.) 20 parts, PV
Yellow HR (yellow organic pigment, manufactured by Hoechst) 2
parts, ethylene glycol monobutyl ether 30
The surface of the white hiding layer 4 was coated with a paint consisting of 0.3 parts of Tinuvin 326 (ultraviolet absorber, manufactured by Ciba Geigy), 0.3 parts of Homogenol L-100, and 0.5 parts of Adetol XL-297 (anti-settling agent, manufactured by Hoechst). It was coated by the same electrostatic coating method as above, and then heat treated at 150° C. for 15 minutes to form a discolored layer 2. In addition, Dianal SE-5248 60 copies, Super Betsucomin G-
After forming a transparent glossy layer 3 in the same manner as above with a paint consisting of 15 parts of 821-60, 10 parts of xylene, and 15 parts of ethylene glycol monobutyl ether, 140
A heat treatment was performed at .degree. C. for 20 minutes to obtain a miniature miniature car with thermoreversible discoloration as shown in FIG. The minichukar takes on a yellow color at a temperature of about 25 degrees Celsius, but
It turns red when immersed in cold water of about 14°C or less, and this change is reversible and can be repeated any number of times, so it can be enjoyed as a toy for young children. (Comparative Example 1) In place of the temperature-sensitive color-changing granules anodized in the color-changing layer 2 of Example 1, 1 part of PSD-V (manufactured by Shin Nisso Chemical Co., Ltd., orange color pigment for pressure-sensitive and heat-sensitive copying paper), bisphenol A1
The same method as in Example 1 was used, except that granules were used, in which a thermochromic composition consisting of 1 part of 1 part, 1.2.3 triazole, and 20 parts of lauryl alcohol was microencapsulated in 6 parts of epoxy resin in the usual manner. Miniature cars were manufactured in Japan, and various qualities were compared as shown in Table 2.

[Table] △: Poor ×: Not acceptable The miniature car of Comparative Example 1 has a markedly reduced color changing function due to the solvent remaining in the paint during manufacture and the adverse effects of heat treatment, making it difficult to commercialize.
On the other hand, the miniature car of Example 1 does not exhibit any deterioration in its discoloration function during manufacture and has excellent product quality in all aspects, so it has an extremely excellent commercial value. (Comparative Example 2) A miniature car was obtained in the same manner as in Example 1 except that the white concealing layer 4 was not provided. (Comparative Example 3) A miniature car was obtained in the same manner as in Example 1 except that the transparent glossy layer 3 was not provided. The miniature cars obtained in Example 1, Comparative Example 2, and Comparative Example 3 were examined for color density, color saturation, gloss, and peeling resistance. Good ones are ○, poor ones are △. Those that were not acceptable were evaluated as ×. Furthermore, regarding light resistance, we measure the color density after exposing the miniature car to sunlight for 3 or 10 days, and the color density immediately after manufacturing is 100%.
It was calculated as These results are summarized in Table 3.

[Table] As is clear from Table 3 above, when no hiding layer is provided (Comparative Example 2), there are problems with the density and chroma during color development, and when no transparent gloss layer is provided ( Comparative Example 3) has poor light resistance, and when exposed to sunlight for a long period of time, the thermochromic function is significantly reduced. (Example 2) Sumamil M40S (alkyd resin, manufactured by Sumitomo Chemical Industries, Ltd.) 75 was applied to the cylindrical side of the metal body 1 of a white stainless steel cup (with a white concealing layer on the stainless steel surface) as shown in Fig. 3. Department, Supervecamine J820-20 (butylated methylolmelamine,
Dainippon Ink Co., Ltd.) 15 parts, Tarene 5100-25 (anti-sagging agent, Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) 5 parts, xylol 5 parts, silicone SH6020 (silane coupling agent, Toray Silicone Co., Ltd.) 1 part, silicone
A pelican pattern 2 was formed using a screen plate with a printing paint consisting of 0.5 part of SH200 (antifoaming agent, manufactured by Toray Silicone Co., Ltd.) and a general organic pigment. Next, Sumimaru M40S 60 parts, Super Betsukamin J820−
20 10 parts, Taren 5100-25 5 parts, Kuromitsu Color S-50 Vermilion (thermoreversible color changing granules,
Matsui Shiki Kagaku Kogyo Co., Ltd.) 25 parts, silicone
Using a spray paint with a viscosity of 2000 cps (Brookfield viscometer) consisting of 1 part SH6020, 0.5 part silicone SH200, and 30 parts xylol, apply it uniformly to a thickness of about 50 μm on the cylindrical side of the cup with a spray gun. A heat treatment was performed at 160° C. for 5 minutes to form a discoloration layer 2 as shown in FIG. Furthermore, Sumimaru
M40S 78 parts, Super Bethcomin J820−20 15
Part, Talen 5100-25 Part 7, Silicone SH6020
1 part, silicone SH200 0.5 part and xylol 25
A fourth coating is applied to the surface of the discoloration layer 2 using a paint consisting of
By forming a transparent glossy layer 3 as shown in the figure, a thermoreversibly discolored stainless steel cup was obtained. At temperatures below 45°C, the front surface of this stainless steel cup only turns dark red as shown in Figure 4, but the color of approx.
When hot water of 50°C or higher was poured, the dark red color almost completely disappeared, and the pelican pattern was clearly visible as shown in Figure 3, and this change was reversible and could be repeated any number of times. . [Effects of the invention] The present invention has a high color density and a sharp and permanent decoloring function on metal surfaces, which could not be achieved with conventional technology, and is highly durable. It makes it possible to form a thermochromic coating film, and its industrial applicability is immeasurable in this respect, coupled with the ease of painting work and low cost.

[Brief explanation of the drawing]

1 and 2 are an enlarged sectional view and an overall front view showing one embodiment of the present invention, respectively, and FIGS. 3 and 4 are an overall front view showing another embodiment of the invention. , Among them, Figure 3 shows that when the temperature is 50℃ or higher,
Figure 4 shows the case where the temperature is below 45°C. In the drawings, 1 is a metal, 2 is a color change layer, 3 is a transparent gloss layer, and 4 is a white concealing layer.

Claims (1)

[Scope of utility model registration request] A granular material in which a concealing layer 4 is formed on the surface of a metal 1, and then a three-component mixture of an acid color developer, an acidic substance, and a solvent is microencapsulated in a thermosetting resin on the concealing layer 4. A color-changing layer 2 is formed using a paint made by blending a thermosetting resin or a thermosetting resin, a thermoplastic resin, and/or an alkyd resin into thermosensitive color-changing granules whose surface is further coated with a hydrophilic polymer compound. , and a transparent glossy layer 3 is further provided on the surface of the discoloration layer 2 using a paint made of a thermosetting resin or a thermosetting resin, a thermoplastic resin, and/or an alkyd resin. Reversible color-changing metals.