JPH0611193Y2 - Thermosensitive discoloration plastic molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermosensitive color-changing plastic molding.

Conventional technology and its problems Plastic molded products have been used for a wide variety of applications in various industries, but since they are colored with dyes and pigments that do not change color, they have a high commercial value in terms of color. Did not have.

By the way, a temperature-sensitive color-changing substance composed of three components, an acid-developing substance, an acidic substance and a solvent, is known. In such a thermosensitive color-changing substance, it is essential to keep the mixing ratio of the three components constant, whereby the coloring density is high, and the coloring and decoloring can be repeatedly repeated sharply due to temperature change, and the hue is Excellent color change function such as richness is exhibited. If this thermochromic substance can be applied to a plastic molded body, it is obvious that its commercial value can be greatly improved.

It is known to mix a thermochromic substance with a synthetic polymer resin to coat the surface of a plastic molded body. However, the temperature-sensitive color-changing substance can be removed by solvent, heat, friction, etc.
It has a drawback that the constant ratio system of components is easily damaged and the discoloration function is impaired. Therefore, when this is added to a paint and coated on a plastic molded body, the discoloring function is impaired by the solvent of the paint or the heating for forming the coating. Even if the thermosensitive color-changing substance is microencapsulated, its solvent resistance, heat resistance, abrasion resistance, etc. are insufficient.

Further, the temperature-sensitive color-changing substance has a drawback that the color-changing function is significantly deteriorated by ultraviolet rays. Therefore, even if the plastic molded body can be coated with the substance, the plastic molded body is often exposed to sunlight, so that the discoloring function cannot be maintained. Attempts have been made to prevent deterioration by adding an ultraviolet absorber, but sufficient effects have not been obtained.

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, the color-changing function of the temperature-sensitive color-changing substance is impaired even during coating processing or exposure to sunlight. We succeeded in obtaining an undisturbed thermochromic plastic molding and completed the present invention.

That is, the present invention provides (i) a plastic molded body, (ii) a color change layer provided on the entire surface or a part of the plastic molded body and containing a thermosensitive color-changing granular material and a transparent synthetic polymer resin, and (Iii) A transparent protective coating layer containing a transparent synthetic polymer resin is provided on the color-changing layer, and the temperature-sensitive color-changing particles are an acid-developing substance, an acidic substance, a solvent and ultraviolet rays. The present invention relates to a thermochromic plastic molded product, characterized in that a mixture containing an absorbent is mixed with a thermosetting resin to be granulated, and the resulting granule is surface-coated with a hydrophilic polymer compound.

According to the research by the present inventor, an ultraviolet absorber is added to a thermosensitive color-changing substance, which is coated with a thermosetting resin and a hydrophilic polymer compound to form a thermosensitive color-changing granular substance, which is formed on a plastic molded body. If a mixed layer (color change layer) of this granular material and a transparent synthetic polymer resin is formed on this, and if a synthetic polymer resin layer is further formed on this mixed layer, the thermochromic substance will deteriorate due to sunlight. It turned out not to. That is, addition of an ultraviolet absorber, coating with a thermosetting resin and a hydrophilic polymer compound,
Each of the constitutions such as mixing the thermosensitive color-changing granules and the transparent synthetic polymer resin and forming the transparent synthetic polymer resin layer act synergistically to prevent the thermochromic substance from being deteriorated by sunlight. , It became clear that the color change function is maintained at a high level. Even if any one of the above configurations is lacking, such an excellent effect cannot be achieved.

Further, by forming a transparent synthetic polymer resin layer,
There is also an advantage that the discoloration layer is strongly protected and the surface gloss is significantly improved. Furthermore, since the temperature-sensitive color-changing granules having excellent solvent resistance, heat resistance, abrasion resistance, etc. are used, the solvent or heat treatment does not impair the constant ratio system of the three components at the time of production, which is excellent. The color change function is demonstrated.

The temperature-sensitive, discolorable plastic molding of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an example of the thermosensitive color-changing plastic molding of the present invention. (1)
Indicates a plastic molded body, (2) indicates a discoloration layer, and (3) indicates a protective coat layer. In FIG. 1, the color change layer (2)
The protective coat layer (3) is formed on one side of the plastic molded body (1), but is not limited thereto and may be formed on the whole surface or a part thereof. Of course, there is no restriction that the protective coat layer (3) should be formed only on the discoloration layer (2), and in the case where the discoloration layer (2) is formed on a part of the plastic molding. Can also be formed on other parts. Color change layer (2)
The temperature-sensitive color-changing particles (2a) are uniformly dispersed in the transparent synthetic polymer resin (2b).

The plastic molded body (1) is not particularly limited, and known ones can be used. As a specific example, for example,
Acrylonitrile butadiene styrene (ABS) resin,
Polystyrene (PS) resin, acrylonitrile styrene (AS) resin, butadiene styrene (BS) resin, polypropylene (PP) resin, polyethylene (PE) resin,
Polyvinyl chloride resin, polymethylmethacrylate (P
Examples include MMA) resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, unsaturated polyester resin, melamine resin, phenol resin, epoxy resin and the like. The shape of the molded product is not particularly limited.

The temperature-sensitive color-changing granular material (2a) contained in the color-changing layer (2) is
It can be produced according to the method described below using a thermochromic substance. The thermochromic substance can be produced by mixing an acid-developing substance, an acidic substance, a solvent and an ultraviolet absorber.

Known substances can be used as the acid-developing substance, for example,
3,3-dimethoxyfluorane, 3-chloro-6-phenylaminofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethyl-7,8-benzofluorane, 3,3 ', Substituted phenylmethane and fluoranes such as 3 ″ -tris (P-diethylaminophenyl) phthalide and 3,3′bis (P-dimethylaminophenyl) -7-phenylaminofluorane, indolylphthalides, spiropyrans, coumarin The acid-developing substance can be used alone or in combination of two or more kinds.

Known substances can be used as an acidic substance that develops a color by combining with an acid-developing substance, and examples thereof include P-phenylphenol, bisphenol A, cresol, mesitol, resorcin, chloroglycine, phenol resin oligomer,
Phenols such as β-naphthol, 5-chlorobenzotriazole, 4-laurylaminosulfobenzotriazole, 5-5'-methylenebis- (benzotriazole), 5-carbethoxybenzotriazoles, and 1,2,3- Examples thereof include benzotriazoles. The acidic substances may be used alone or in combination of two or more.

Known solvents can be used as a solvent for coexisting the acid-developing substance and the acidic substance, for example, alcohols such as octyl alcohol, myricyl alcohol, stearyl alcohol, geraniol, lauryl stearyl acid, glyceryl palmitate, etc. And azomethines such as benzylideneaniline and benzylidenelaurylamine, and amides such as acetoamide and stearic acid amide. Solvents can be used alone or in 2
It can be used in combination of two or more species.

Known ultraviolet absorbers can be used. Specific examples thereof include phenyl salicylate P-tert.
-Butylphenyl salicylate, salicylic acid compounds such as P-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy- Benzophenone-based compounds such as 4,4′-dimethoxybenzophenone, 2-
(2'-hydroxy-5-methylphenyl) benzotriazole, 2- (2'-hydroxy-5-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert- Examples thereof include butylphenyl) benzotriazole and 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole. The ultraviolet absorbers can be used alone or in combination of two or more kinds. The blending amount of the ultraviolet absorber is not particularly limited, but is usually about 1 to 20 parts by weight, preferably about 3 to 10 parts by weight, relative to 100 parts by weight of the total of the three components of the acid developer, the acidic substance and the solvent. do it.
The mixing ratio of the acid-developing substance, the acidic substance and the solvent is not particularly limited and may be appropriately selected.

The thermosensitive color-changing granules (2a) can be obtained by mixing a thermosensitive color-changing substance with a thermosetting resin to granulate it according to a known method such as an interfacial polymerization method or an in-site polymerization method. It can be produced by mixing with a hydrophilic polymer compound and coating the surface of the granular material with the hydrophilic polymer compound. Known thermosetting resins can be used, and examples thereof include unsaturated polyester resins, polyurethane resins, melamine resins, and epoxy resins. Known hydrophilic polymer compounds can be used, and examples thereof include polyvinyl alcohol, polyacrylic acid and salts thereof, gelatin, methyl cellulose, and alginic acid.
The particle size of the thermosensitive color-changing granular material (2a) is not particularly limited, but is usually about 1 to 50 μm, preferably about 3 to 15 μm.

The synthetic polymer resin (2b) which is another component of the color change layer (2) is not particularly limited as long as it is transparent.
In this specification, the term “transparent” also includes the case of being semi-transparent. Specific examples of the synthetic polymer resin (2b) include thermosetting resin, thermoplastic resin, alkyd resin and the like. As the thermosetting resin, the same ones as described above can be used. Known thermoplastic resins can be used, and examples thereof include vinyl chloride resin, chlorinated polyethylene resin, chlorinated polypropylene resin, vinyl acetate resin, and acrylic resin. Known alkyd resins can be used. These resins may be used alone or in combination of two or more, and may be used by copolymerizing or cocondensing.

A known method can be used for forming the color-change layer (2) on the plastic molded body (1). For example, thermosensitive color-changing granular material (2a) and transparent synthetic polymer resin (2b)
To a solvent solution, a solvent dispersion, an aqueous dispersion or an emulsion, and if necessary, a dye or pigment, a plasticizer, a desiccant, etc. are added to form a paint, and the paint is sprayed, brushed, dipped or the like to form a plastic. After applying to the surface of the molded body, heat treatment may be performed at about 50 to 180 ° C. for about 5 to 60 minutes. The amount of the thermosensitive color-changing granules (2a) contained in the above-mentioned coating material is not particularly limited, but it is usually preferable to add about 1-40 parts by weight to 100 parts by weight of the coating material. The solvent may be appropriately selected and used. The thickness of the color-change layer (2) is not particularly limited, but usually 2
It may be about 0 to 200 μm.

Then, a coating material containing a transparent synthetic polymer resin is applied onto the discoloration layer (2), and heat treatment is performed under the same conditions as those for forming the discoloration layer (2) to form a transparent protective coat layer (3). Form. As the transparent synthetic polymer resin, the same ones as described above can be used. Although the thickness of the protective coat layer (3) is not particularly limited, it is usually about 20 to 1000 μm.

In the present invention, as shown in FIG. 2, a concealing layer (4) containing a concealing substance is formed between the plastic molded body (1) and the color-changing layer (2) to make the color change more sensitive. Can be determined. As the hiding substance, known substances can be used, and examples thereof include titanium oxide, zinc oxide, calcium carbonate, barium sulfate, and aluminum silicate. The hiding substance can be used alone or in combination of two or more kinds. The hiding substance may be a coating material together with the transparent synthetic polymer resin, which may be applied onto the molded body (1) and heat-treated in the same manner as above.

Further, as shown in FIG. 3 or 4, a primer layer (5) may be provided between the molded body (1) and the color-changing layer (2) or the hiding layer (4). Thereby, the discoloration layer (2) or the concealing layer (4) is more firmly fixed to the molded body (1). In particular, when the resin component constituting the plastic molded body is a resin component having almost no polarity, such as a polyolefin resin, the discoloration layer (2) or the hiding layer (4) and the molded body are It is desirable to provide a primer layer because sufficient fixation between them cannot be expected. Known primers can be used as the primer, and examples thereof include an acrylic primer, an epoxy two-component primer, and a urethane two-component primer.

In addition, the above-mentioned granular material and each coating material may contain a chemical agent which is usually used in molding a plastic. Specific examples thereof include extender pigments, surfactants, plasticizers, antioxidants, desiccants, wetting agents, penetrants, anti-sagging agents, anti-settling agents, color separation preventing agents, anti-skin agents, A flame retardant, a defoaming agent, a leveling agent, a coupling agent, an antistatic agent, etc. can be mentioned.

Effect of the Invention According to the present invention, the surface sensitively senses a temperature change, the color reversibly changes, and the gloss and light resistance of the color are extremely excellent. A discolorable plastic molding can be provided.

EXAMPLES The present invention will be made clearer with reference to reference examples, examples and comparative examples below. In the examples, "parts" means "parts by weight".

Reference Example 1 (Method for producing thermosensitive color-changing granules) 200 parts of water containing 2 parts of Demol N [surfactant, manufactured by Kao Corporation] was heated to 90 ° C., and NCB [acid-developing substance was added thereto]. , Leuco dye, Hodogaya Chemical Co., Ltd.] 3 parts, bisphenol A (acidic substance) 3 parts, 5,5'-methylenebisbenzotriazole (acidic substance) 3 parts, lauryl alcohol (solvent) 50 parts and tinuvin P [UV absorber,
A heated melt obtained by melting 4 parts of Ciba-Geigy Co., Ltd. was charged under stirring, and the stirring speed was adjusted so that the average particle diameter of the emulsion was about 5 μm. When the emulsified state became stable, 20 parts of a 50% methylol melamine aqueous solution (thermosetting resin) was added with stirring, then 2 parts of an acid catalyst (10% ammonium chloride) was added, and the mixture was stirred at 90 ° C. for 1 hour to obtain an acid. A dispersion liquid of solidified granules was obtained by co-encapsulating the above-mentioned 5 components including a color-developing substance with a melamine resin. Take this out,
It was heat-treated at 120 ° C. for 2 hours in a hot air dryer to completely solidify it. The obtained granular material is dispersed in 200 parts of a 3% aqueous solution of polyvinyl alcohol, 120 parts of a 10% aqueous solution of carboxymethyl cellulose (hydrophilic polymer compound) is added thereto, and 13 parts of a 10% aqueous solution of calcium chloride is gradually added under vigorous stirring. Was added dropwise. After stirring for 30 minutes, the granular material was taken out and dried, and the outer layer was coated with carboxymethyl cellulose,
About 65 parts of thermosensitive color-changing granules having an average particle diameter of 10 μm were obtained. The color change temperature of the granules was about 17 ° C.

The thermosensitive color-changing granules ~ were produced in the same manner as above except that the acid-developing substance and the solvent were changed to those shown in Table 1.

Example 1 The surface of a high-impact polystyrene molded body was washed with isopropyl alcohol (IPA) and degreased, and then 60 parts of ACRYDIC A-151-35 [acrylic resin solution for constant drying, manufactured by Dainippon Ink and Chemicals, Inc.] , 20 parts of thermochromic granules, 10 parts of butyl cellosolve and 1 of isoamyl acetate
A paint consisting of 0 parts was applied with a spray gun, left for 5 minutes and then heat-treated at 50 ° C. for 30 minutes to form a color change layer having a film thickness of 60 μm.

Next, 60 parts of ACRYDIC A-801 [acrylic polyol, manufactured by Dainippon Ink and Chemicals, Inc.] on the surface of the discoloration layer,
Burnock D-750 [polyisocyanate, manufactured by Dainippon Ink and Chemicals, Inc.] 3 parts, aliphatic petroleum naphtha 30 parts,
A transparent paint consisting of 10 parts of butyl cellosolve and 10 parts of xylene is applied, left for 5 minutes, and then heat-treated at 50 ° C. for 40 minutes to form a protective coating layer having a film thickness of 80 μm. Obtained. This molded body is about 1
It became blue-purple below 7 ° C, and became colorless above that. The color change was reversibly repeated.

Comparative Example 1 A thermochromic plastic molding was obtained in the same manner as in Example 1 except that the thermochromic granular material was not coated with carboxymethylcellulose (hydrophilic polymer substance) and the protective coat layer was not formed. It was

Comparative Example 2 A thermosensitive color-changing plastic molded product was obtained in the same manner as in Example 1, except that the thermosensitive color-changing granular material did not contain 4 parts of TINUVIN P.

Comparative Example 3 AP-106 [a phenol resin solution for paints, manufactured by Gunei Chemical Industry Co., Ltd.] which is an opaque synthetic resin component instead of 60 parts of ACRYDIC A-151-35 which is a transparent synthetic resin component in the discoloration layer Example 1 except that 60 parts were used
In the same manner as in (1), a thermochromic plastic molding was obtained.

Comparative Example 4 A thermosensitive color-changing plastic molding was obtained in the same manner as in Example 1 except that the protective coat layer was not formed.

Comparative Example 5 AP-107 [phenolic resin for paints, Gunei Chemical Industry Co., Ltd., which is an opaque synthetic resin component instead of 60 parts of transparent synthetic resin components Acridic A-801 and 3 parts of Barnock D-750 in the protective coat layer A thermosensitive color-changing plastic molded product was obtained in the same manner as in Example 1 except that 63 parts (manufactured by K.K.) were used.

For the molded articles of Example 1 and Comparative Examples 1 to 5, the density at the time of color development (the density of Example 1 after exposure to sunlight for 5 hours was 100
), Residual color at the time of erasing, and light resistance (JIS L-084
2-71), and the physical properties of surface gloss, smoothness, strength and durability were compared. The surface gloss, smoothness, strength and durability were evaluated according to the following criteria. The results are shown in Table 2.

 A: Excellent.

 ○: Good.

 Δ: Inferior

 ×: It cannot be used.

From Table 2, it can be seen that the molded product of Example 1 is excellent in all aspects, and particularly excellent in light resistance.

Example 2 After washing the surface of a white ABS molded body with IPA, 60 parts of Beckolite M-6003-60 [oil-free alkyd resin, Dainippon Ink and Chemicals, Inc.], Vernock DN-950
[Polyisocyanate, Dainippon Ink and Chemicals, Inc.
3 parts, 20 parts of color-changing granules and aliphatic naphtha 1
A paint consisting of 7 parts was applied with a spray gun. After standing for 5 minutes, heat treatment was carried out at 60 ° C. for 30 minutes to form a color change layer having a thickness of 80 μm.

Then, on the surface of the discoloration layer, Acridic A-808 [acrylic polyol, manufactured by Dainippon Ink and Chemicals, Inc.] 75
Part, 5 parts of Barnock DN-950 and 20 parts of aliphatic petroleum naphtha are applied, left for 5 minutes and then heat treated at 60 ° C. for 40 minutes to form a transparent coating layer having a film thickness of 100 μm. Got the body This molded body became vermilion at about 17 ° C. or lower and became colorless at higher temperatures. The color change was reversibly repeated. In addition, since the surface gloss is remarkably excellent, it had a visually appealing beauty.

Example 3 After the surface of a polypropylene molded body was degreased and washed with 1,1,1-trichloroethane, 60 parts of HARDREN 15A [chlorinated polypropylene resin solution, manufactured by Toyo Kasei Co., Ltd.], 20 parts of thermosensitive color-changing granules , Chloello MF2G powder [fluorescent pigment, manufactured by Matsui Dye Chemical Industry Co., Ltd.] and 2 parts of aliphatic naphtha, and after leaving for 5 minutes, heat treatment at 50 ° C. for 10 minutes to give a film thickness of 80 μm. The discoloration layer of No. 1 was used.

Then, a coating consisting of 75 parts of Hardlene 15-A and 25 parts of aliphatic naphtha was applied to the surface of the discoloration layer, allowed to stand for 5 minutes, and then heat treated at 60 ° C. for 20 minutes to form a protective coating layer having a thickness of 100 μm. The molded body of the present invention was obtained. This molded product turned orange at about 35 ° C or lower, and yellow at higher temperatures. The color change was reversibly repeated. Moreover, because it is always glossy, it was beautiful and eye-catching.

Example 4 A nonyl resin (modified polyphenylene oxide) molding was used as I
After degreasing and washing with PA, 55 parts of Acridic A-808,
A coating consisting of 25 parts of thermosensitive color-changing granules, 0.1 part of phthalocyanine blue (organic pigment), 10 parts of Bernock DN-950 and 10 parts of aromatic naphtha was applied, and after being left for 5 minutes, heat treated at 70 ° C for 30 minutes. Then, a color change layer having a film thickness of 80 μm was formed.

Then, on the surface of the color change layer, Burnock D-150-70 [polyester polyol, Dainippon Ink and Chemicals, Inc.
75 parts, Vernock D-500 [polyisocyanate, manufactured by Dainippon Ink and Chemicals, Inc.] 5 parts, xylene 1
Apply a paint consisting of 5 parts and 5 parts butyl cellosolve,
After leaving for 5 minutes, heat treatment at 80 ℃ for 30 minutes, film thickness 100μ
A protective coat layer of m was formed to obtain a molded product of the present invention. This molded product exhibited a green color at a temperature of about 25 ° C. or lower, and a blue color at a temperature higher than about 25 ° C. The color change was reversibly repeated. Moreover, because of its excellent luster, it was full of luxury.

Example 5 After degreasing and cleaning the surface of a polycarbonate molded body with Freon vapor, 30 parts of Epicoat 828 [epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd.], Epomate B-001 [curing agent, manufactured by Yuka Shell Epoxy Co., Ltd.] 18 parts, 40 parts of aliphatic petroleum naphtha, 12 parts of butyl cellosolve and silicone SH-
5500 0.2 parts epoxy 2 part primer was applied, left for 5 minutes, then heat treated at 90 ° C for 30 minutes to obtain a film thickness of 10
A μm primer layer was formed.

Then, on the primer layer, Beckolite M-6003-60
60 parts, 20 parts thermosensitive color-changing granules, glow pink M
F2G [fluorescent pigment, manufactured by Matsui Dye and Chemical Industry Co., Ltd.] 0.
5 parts, 3 parts of Bernock DN-950, 12 parts of xylol and 5 parts of butyl cellosolve are applied,
Heat treatment was performed at 0 ° C. for 30 minutes to form a color change layer having a film thickness of 90 μm.

Furthermore, 60 parts of Acridic A-801,
A transparent coating consisting of 3 parts of Bernock D-750, 10 parts of butyl cellosolve and 10 parts of xylene was applied, and after standing for 5 minutes, heat treatment was carried out at 120 ° C. for 30 minutes to form a protective coating layer having a film thickness of 120 μm. The obtained molded product exhibited a blue color at about 21 ° C. or lower, and a pink color at higher temperatures. The color change was reversibly repeated.

Example 6 Between the polypropylene molded body and the color change layer, a hard lens 15
-A 60 parts, titanium oxide powder 2 parts and aliphatic naphtha 1
A molded product of the present invention was obtained in the same manner as in Example 3 except that a coating material consisting of 8 parts was applied to form a hiding layer having a film thickness of 50 μm.

This molded product turned orange at about 35 ° C. or lower, and yellow at higher temperatures, but each color was more vivid than that of Example 3 and was excellent in glossiness and further high-class feeling. Was granted.

[Brief description of drawings]

1 to 4 are cross-sectional views of an example of the thermosensitive color-changing plastic molding of the present invention. (1) ... Plastic molding (2) ... Discoloration layer (2a) ... Temperature-sensitive discoloration granular material (2b) ... Transparent synthetic polymer resin (3) ... Protective coat layer (4) ... Hiding layer (5) ... Primer layer

Claims (3)

[Scope of utility model registration request] 1. An (i) plastic molded body, (ii) a color change layer which is provided on the entire surface or a part of the plastic molded body and which contains temperature-sensitive color-changing particles and a transparent synthetic polymer resin. (Iii) A transparent protective coating layer containing a transparent synthetic polymer resin is provided on the color-changing layer, and the temperature-sensitive color-changing particles are an acid-developing substance, an acidic substance, a solvent and ultraviolet rays. A thermochromic plastic molding, characterized in that a mixture containing an absorbent is mixed with a thermosetting resin to form granules, and the obtained granules are surface-coated with a hydrophilic polymer compound. 2. The thermosensitive color-changing plastic molded product according to claim 1, wherein a masking layer containing a masking substance and a transparent synthetic polymer resin is provided between the plastic molded product and the color-changing layer. 3. The thermosensitive color-changing plastic molded product according to claim 1, wherein a primer layer is provided between the plastic molded product and the discoloration layer or between the plastic molded product and the concealing layer.