JPH07100769B2 - Color memory paint - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a paint that provides a color memory coating film capable of retaining different colors at room temperature.

2. Description of the Related Art Conventionally, various paints using a reversible thermochromic material have been disclosed (for example, Japanese Patent Publication No. 51-35414), but a coating film provided by these paints has a color change temperature of the thermochromic material as a boundary. The color changes only repeatedly due to the ambient temperature change, and the color that has once changed returns to the original color due to the temperature change.

Further, the coating film of the coating material using the irreversible thermochromic material does not return to the original color once the color is changed.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention can retain both the color on the lower temperature side and the color on the higher temperature side than the discoloration temperature in the normal temperature range, and dissipates any color by applying heat or cold heat as necessary. It is an object of the present invention to provide a color-memory paint that gives a coating film that can be repeated.

Means and Actions for Solving Problems The color memory paint of the present invention contains 1 to 100% by weight of a temperature-dependent color memory material in the nonvolatile content.

The temperature-dependent color memory material exhibits a hysteresis width of 5 ° C. to 80 ° C. with respect to a color density-temperature curve, and a Δt value of 1 ° C. to 30 ° C. (difference between color development / erasing branch temperature and maximum holding temperature).
Of the quasi-reversible thermochromic composition.

Hereinafter, the hysteresis characteristics in the color density-temperature curve of the temperature-dependent color memory material will be described with reference to the graph shown in FIG.

The vertical axis of the graph is the color density, the horizontal axis is the temperature,
A is the point showing the concentration at the lowest temperature T ₄ (hereinafter referred to as the color development / decoloration branch temperature) reaching the color development / decoloration branch point, and B is the maximum temperature T ₃ (hereinafter, the maximum temperature retention) at which the completely colored state can be maintained. (Hereinafter referred to as temperature), and C is a point at which the density is at the lowest temperature T ₂ (hereinafter referred to as the minimum holding temperature) at which the completely decolored state can be maintained, and D is at the completely colored state. This is a point indicating the density at the maximum temperature T ₁ (hereinafter, referred to as perfect coloring temperature) to be reached. At the temperature T _a , the two phases of the colored state E point and the decolored state F point coexist. This includes a temperature T _a, is capable of holding the temperature range of the temperature range the color development state and decolored state can coexist discoloration, a measure of the length of the line segment EF indicates the magnitude of contrast of color change, the line segment The length of the line segment HG passing through the midpoint of EF is the temperature width (hereinafter referred to as hysteresis width ΔH) that represents the degree of hysteresis.
The larger the value, the easier the retention of discoloration. In the experiments conducted by the present inventors, the ΔH value that can maintain the practical discoloration is 5 ° C. to 80 ° C.
It is in the range of 8 ° C, preferably in the range of 8 ° C to 80 ° C.

Coloring / decoloring branching temperature T ₄ is the curve of the color density of the color memory material.
It is the minimum temperature required to make the transition from DEBGA to curve AFCHD, and the transition does not occur at temperatures below T ₄ . For example the concentration at any temperature T _b is slightly lower than T ₄ 'and point, what is the point E at the temperature T _a to the curve EBGA heated to T _b' A reaches the path by point A '. When it is cooled to T _a again, it returns to the point E by the path of the curve A′GBE, and the color is not retained. However, when heated to T ₄ , it reaches the point A by the curved EBGA route, and when cooled, it reaches the F point on the AF route, making it possible to maintain the color.

Here, the difference Δt between the color development / decoloration branching temperature T ₄ and the maximum holding temperature T ₃ is a measure showing the sensitivity of discoloration, and it is desirable that it is small, but if it is in the range of 1 ° C to 30 ° C, it can be put to practical use. it can.

The quasi-reversible thermochromic material having such properties is useful in practical use, and this is named a temperature-dependent color memory material.

The temperature-dependent color memory material quasi-reversibly causes the color reaction of (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) the above-mentioned components (a) and (b). A quasi-reversible thermochromic composition composed of a homogeneous compatible solution containing three components of a compound serving as a medium as an essential component, the desired function being a weight ratio of component (b) to component (b) 0.1 to 50, Preferably
It is obtained from a composition in the range of 0.5 to 20, component (c) 1 to 800, preferably 5 to 200. Further, each component may be a mixture of two or more kinds, and may be an antioxidant, an ultraviolet absorber, an infrared absorber, a solubilizing agent, a diluent, as long as the function is not impaired.
A sensitization aid and the like can also be added.

Each of the above components will be specifically described below.

The electron-donating color-developing organic compound of the component (a) is a diarylphthalide, a polyarylcarbinol, a leuco auramine, an acyl auramine, an aryl auramine, a rhodamine B lactam, an indoline, a spiropyran. , A so-called leuco dye, which is a substantially colorless compound selected from fluoran compounds.

These compounds are exemplified below.

Crystal Violet Lactone, Malachite Green Lactone, Michler Hydrol, Crystal Violet Carbinol, Malachite Green Carbinol, N
-(2,3-Dichlorophenyl) leukoauramine, N-
Benzoyl leuco auramine, rhodamine B lactam,
N-acetyl auramine, N-phenyl auramine, 2
-(Phenyliminoethylidene) -3,3-dimethylindoline, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 8-methoxy-N-3,3-trimethylindolinobenzspiropyran , 2-chloro-
3-methyl-6-diethylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 2-dibenzylamino-3-methyl-6-diethylaminofluorane, 3-diethylamino-7-methoxyfluorane, 3
-Diethylamino-6-benzyloxyfluorane, 1,
2-benz-6 diethylaminofluorane, 3,6-di-p
-Triidino-4,5-dimethylfluorane-phenylhydrazide-γ-lactam, 3-amino-5-methylfluorane, 2,6,7-trimethyl-3-aminofluorane,
2,3-butylene-6-di-n-butylaminofluorane, 3-diethylamino-7- (p-toluidino) fluorane, 7-acetamino-3-diethylaminofluorane, 2-bromo-6-cyclohexylaminofluorane , 2,7-chloro-3-methyl-6-n-butylaminofluorane and the like.

Next, the component (b) will be described.

As the electron-accepting compound of the component (b), a group of compounds having an active proton, a group of pseudo-acidic compounds (a group of compounds that are not acids but that act as an acid in the composition to develop the component (a)), electron vacancy There is a group of compounds having pores. Examples of compounds having active protons include compounds having a phenolic hydroxyl group such as alkylphenols, other substituted phenols, bisphenols, polyphenols, and phenol-aldehyde condensation resins, having 2 to 5 carbon atoms.
Aliphatic carboxylic acids, 1,2,3-triazoles, cyclic carbosulfoimides, halohydrins, acidic phosphoric acid esters, pyrroles, oxazoles, thiazoles,
There are aromatic carboxylic acids, sulfonic acids, inorganic acids, silica gel and the like. As the pseudo-acidic compound, a metal salt of a compound having a phenolic hydroxyl group, a metal salt of an aliphatic carboxylic acid, a metal salt of an acidic phosphoric acid ester, an aromatic carboxylic acid anhydride, an aromatic carboxylic acid-sulfonic acid anhydride, cyclo Olefin dicarboxylic acid anhydride, ureas, thioureas,
There are guanidines. Examples of compounds having electron vacancies include boric acid esters, borate salts, halides and oxides of Group I, Group II and Group III metals in the periodic table.

As the medium organic compound of the component (c), (1) a carboxylic acid ester containing a substituted aromatic ring in the molecule, (2) an ester of a carboxylic acid containing an unsubstituted aromatic ring and an aliphatic alcohol having 10 or more carbon atoms, (3) a carboxylic acid ester containing a cycloalkyl group in the molecule, (4) an ester of a fatty acid having 6 or more carbon atoms and an unsubstituted aromatic alcohol, (5) an ester of a fatty acid having 8 or more carbon atoms and a branched aliphatic alcohol, (6)
Dicarboxylic acid and aromatic alcohol, selected from ester compounds consisting of diesters of branched aliphatic alcohols or aliphatic alcohols having 10 or more carbon atoms, stearyl 2-methylbenzoate, cetyl 4-tert-butylbenzoate, 4-
Behenyl cyclohexylbenzoate, myristyl 4-phenylbenzoate, lauryl 4-octylbenzoate, 3,5-
Hexyl dimethyl benzoate, stearyl 3-ethyl benzoate, butyl 4-benzyl benzoate, 3-methyl-5-
Octyl chlorobenzoate, stearyl 4-benzoylbenzoate, stearyl 1-naphthoate, cetyl benzylate, stearyl benzylate, phenyl 4-tert-butylbenzoate, 4-chlorobenzyl 2-methylbenzoate,
Stearyl 4-chlorobenzoate, myristyl 3-bromobenzoate, stearyl 2-chloro-4-bromobenzoate, decyl 3,4-dichlorobenzoate, octyl 2,4-dibromobenzoate, cetyl 3-nitrobenzoate, Cyclohexylmethyl 4-aminobenzoate, cetyl 4-diethylaminobenzoate, stearyl 4-anilinobenzoate, 4-
Decyl methoxybenzoate, cetyl 4-methoxybenzoate, stearyl 4-methoxybenzoate, octyl 4-butoxybenzoate, cetyl 4-butoxybenzoate, 4-methoxybenzyl benzoate, benzyl benzoate, cetyl p-chlorophenylacetate, Stearyl p-chlorophenylacetate, decyl 3-benzoylpropionate, benzyl salicylate, neopentyl salicylate, 4-methoxybenzyl salicylate, 4-chlorobenzyl benzoate, stearyl benzoate, cetyl benzoate, myristyl benzoate,
Benzyl cinnamate, cyclohexylmethyl cinnamate, benzyl caproate, 4-chlorobenzyl caprate, 4-methoxybenzyl myristate, 4-methylbenzyl stearate, benzyl palmitate, 4-nitrobenzyl stearate, cyclohexyl laurate, myristin Acid cyclohexyl, cyclohexyl palmitate, cyclohexyl methyl stearate, cyclohexyl ethyl stearate, neopentyl caprylate, neopentyl laurate, neopentyl stearate, 3-phenylpropyl stearate, stearyl cyclohexyl acetate, stearyl 2-cyclohexylpropionate, stearyl cyclohexyl formate. , 4-methylpentyl caproate, 2-chlorobenzyl myristate, capric acid 4
-Methoxybenzyl, cyclohexyl 2-benzoylpropionate, 4-chlorophenyl 11-bromolaurate, 4-isopropylbenzyl stearate, didecyl adipate, dilauryl adipate, dimyristyl adipate, dicetyl adipate, distearyl adipate, sebacate Distearyl, dibenzyl sebacate,
Ester compounds such as distearyl terephthalate, dineopentyl 4,4'-diphenyldicarboxylate, and dibenzyl azodicarboxylate are useful.

On the other hand, by encapsulating the temperature-dependent color memory material in a microcapsule by a known microencapsulation technique,
It can also be made easier to apply to paints.

More specifically, since it is protected by the capsule membrane wall, even if it comes into contact with a chemically active substance such as an acidic substance, a basic substance, a peroxide or another solvent component, its function is It does not lower. Available microencapsulation techniques include interfacial polymerization, in situ polymerization, submerged curing coating, phase separation from aqueous solution, phase separation from organic solvent, melt dispersion cooling, air suspension coating, There is a spray drying method, etc., which is appropriately selected and used according to the application.

Next, the vehicle used in the coating material of the present invention will be described.

Examples of the cooling and solidifying type (hot melt type) include carnauba fox, paraffin wax, and microcrystalline wax.

Evaporative drying type (resin / solvent type) is rosin, shellac, casein, rosin-maleic acid resin, alkyd resin, cellulose derivative, petroleum resin, low molecular weight polyethylene, polystyrene, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer Coalesced, polyacrylic acid type resin, modified rubber,
There are solutions in which a resin such as polyvinyl alcohol or polyvinyl pyrrolidone is dissolved in a petroleum solvent, an aromatic solvent, an aliphatic hydrocarbon solvent, an alcohol solvent, a ketone solvent, an ester solvent, or water.

As the permeation dry type (resin / petroleum solvent type), there is a solution in which a resin such as rosin or rosin derivative is dissolved in machine oil, spindle oil, kerosene or the like.

Emulsion type vinyl copolymer latex,
Synthetic rubber type latex, polyacrylic acid ester type latex and the like are available.

As the oxidative polymerization type, there are drying oils such as polymerized linseed oil, tung oil, dehydrated castor oil and oteca oil, and oil modified alkyd resins such as soybean oil modified alkyd resin, coconut oil modified alkyd resin and linseed oil modified alkyd resin.

Examples of the thermosetting resin type include epoxy resin, amino resin, heat-reactive unsaturated hydrocarbon resin and urethane resin.

Examples of the photocurable type include photopolymerizable acrylic resin and photocurable epoxy resin.

The paint of the present invention is the temperature-dependent color memory material (hereinafter,
(Abbreviated as a colorant) is dispersed or dissolved in the vehicle, and if necessary, a plasticizer, a colorant, a thickener, a dispersant, an ultraviolet absorber, an anti-settling agent, a flattening agent, a fungicide, etc. It is made by adding additives.

The three-dimensional coated article of the present invention is formed by coating the coating material on a part or all of the surface of a three-dimensional object made of a material such as plastics, wood, glass, ceramics, stones, and metals. The surface may be provided with usual decorations or symbols, and a coated surface may be provided with a transparent protective layer.

For painting, brush painting, air spray painting, airless spray painting, hot spray painting, dip coating, flow coating,
Means such as roller coating, curtain flow coating and powder coating are used.

The object to be coated is three-dimensional, but this is because it is difficult to print on the surface of the three-dimensional object. Therefore, even if one surface of the object to be coated is a flat surface, that surface is a part that constitutes a three-dimensional object. Is subject to.

Example First, an example of a temperature-dependent color-storing memory material, colorants A and A '.
Is described.

Colorant A (parts of composition are parts by weight) (a) Crystal violet lactone 1.0 part (b) Bisphenol A 2.0 (c) Neopentyl stearate 27.0 Component (a) (b) (c) dissolved by heating at 100 ° C for 10 minutes And homogenize to make colorant A.

Colorant A ′ Colorant A is isolated by encapsulating the colorant A in a microcapsule of an epoxy resin film by an interfacial polymerization method.

Hereinafter, the number of parts of the composition of the coating material is expressed by parts by weight.

Example 1 Low molecular weight polyethylene 50.0 parts (average molecular weight 2,000, softening point 107 ° C, density 0.93) Ethylene-vinyl acetate copolymer 48.4 parts (vinyl acetate content 25%, softening point 4 ° C, density 0.95 g / c
m ³ ) Colorant A 1.6 parts All components are heated and melted at 120 ° C for 15 minutes and homogenized to obtain a paint.

Example 2 Low-molecular-weight polyethylene 20 parts (average molecular weight 2,000, softening point 107 ° C, density 0.93) Polyacrylic ester 5 parts (average molecular weight about 70,000, softening point 100 ° C) Colorant A 10 parts xylene 65 parts All components are xylene Dissolve into a paint.

Example 3 Polyacrylic acid ester 20 parts (molecular weight about 70,000, softening point 100 ° C.) Colorant A 10 parts Xylene 40 parts MIBK 30 parts All components are heated and melted at 70 ° C. for 20 minutes to prepare a paint.

Example 4 20 parts of chlorinated rubber (molecular weight of about 5,000, chlorine content of 65%, specific gravity of 1.60) Colorant A 15 parts xylene 40 parts butyl acetate 25 parts All components are heated and melted at 60 ° C. for 20 minutes to prepare a paint.

Example 5 Ammonia aqueous solution of 10% styrene-maleic acid copolymer 80
Parts (polymer molecular weight 20,000, softening point 235 ° C., specific gravity 1.16) Colorant A ′ 20 parts Stir-mix for 10 minutes and disperse uniformly to obtain a coating material.

Example 6 Vinyl acetate emulsion 50 parts (nonvolatile content 50%, viscosity 12,000 at 25, specific gravity 1.08) Colorant A'25 parts Water 25 parts Stir-mix for 10 minutes to uniformly disperse the colorant to obtain a coating material.

Example 7 Rosin-modified maleic acid resin 40 parts Xylene 30 parts Colorant A'30 parts A colorant is uniformly dispersed in a vehicle in which a resin is dissolved in xylene to prepare a paint.

Example 8 Epoxy resin 85 parts (diglycidyl ether type epoxy resin, epoxy equivalent
190) Colorant A'10 parts Diethylenetriamine (curing agent) 5 parts Colorant is uniformly dispersed in epoxy resin, the curing agent is added immediately before use, and mixed to prepare a coating material.

Example 9 Vinyl chloride-vinyl acetate copolymer 15 parts (vinyl chloride content 14%, specific gravity 1.36) MIBK 40 parts Xylene 30 parts Colorant A'15 parts Colorant is homogeneous in a vehicle in which the polymer is dissolved in a solvent. Disperse into the paint.

Example 10 The paint of Example 3 was applied over the entire surface of a white ABS model car by the air spray method. This coating contains 33% of colorant and has a hysteresis width ΔH = regarding the color density-temperature curve.
It exhibits a characteristic of 20 ° C, the difference Δt = 2 ° C between the color development and decolorization branch temperature and the maximum holding temperature. It exhibits blue below 15 ° C, white above 35 ° C, and white at any temperature between 17 ° C and 33 ° C. I was able to choose blue. That is, if a white color is desired, it can be heated to 35 ° C or higher and kept white unless it is cooled to 15 ° C. In addition, you can write letters and designs with a cold pen on a white background and a hot pen on blue, and they are held in the temperature range of 17 to 33 ° C as described above, and heat of 35 ° C or higher or cold heat of 15 ° C or lower. It can be erased by application, and this discoloration and retention can be repeated any number of times.

Example 11 Leuco dye A (chemical structure will be described in detail later) 2.0 g, 1,2,3-
Benzotriazole 12.0g, neopentyl stearate 3
In-situ the compatible solution obtained by melting and mixing 6.0g at 110 ℃ for 10 minutes.
A coloring agent was obtained by encapsulating it in a microcapsule of a urea resin film by a polymerization method, and a coating material was prepared by the same vehicle, composition ratio and manufacturing method as in Example 9.

This paint was applied by brushing on the surface of a soft vinyl chloride shrimp-shaped molded toy. The coating film contains colorant
It was 50% by weight, and exhibited characteristics of ΔH = 20.0 ° C. and Δt = 3 ° C. When the toy was soaked in cold water, it turned orange, and the appearance was as if the shrimp had risen to the eggplant. Furthermore, this color was retained in the normal temperature range, and when heated with hot water or a dryer, the original color was obtained, and the color was reusable.

Example 12 Leuco dye B 2.7 g, 2,3-xylyl acid phosphate
8.4g, cetyl 4-tert-butyl benzoate 60g at 100 ℃, 10
The compatible solution obtained by partial heating and melting was encapsulated in a microcapsule of an epoxy resin film by an interfacial polymerization method to give a colorant, and this colorant was used to prepare a paint by the same vehicle, composition ratio and manufacturing method as in Example 6. did.

This paint was applied to the white wall inside the room using a roller. This coating film contains 50% by weight of colorant, ΔH = 3
The characteristics were 7.8 ° C. and Δt = 8 ° C. The coated surface became pink above 40 ° C and white below 0 ° C, and white and pink could be selected and held in the temperature range of 0 to 40 ° C.

Example 13 Leuco dye D1.5 g, 1,3-diphenylguanidine 12.0 g,
Distearyl adipate 47 g was heated at 100 ° C for 10 minutes and melted to obtain a compatible solution, which was then encapsulated in a microcapsule of a gelatin-gum arabic complex film by a coacervation method as a coloring agent. A paint was prepared by using the same vehicle, composition ratio and manufacturing method as in Example 4. The coating film of this paint contains 40% by weight of colorant, ΔH = 77.8 ° C, Δt = 2
It shows the characteristic of 9.0 ℃, and the reddish red color disappears at about 85 ℃.
It was not recolored unless it was cooled to ℃. Therefore, it can be used as an apparently irreversible temperature-indicating paint and can be applied to the measurement of the surface temperature distribution of an internal combustion engine.

Example 14 The surface of a white leather product (bag, bag, shoes) coated with the paint of Example 9 on the surface thereof after airless spray coating
A 20% polyacrylic acid ester-toluene solution (polymer molecular weight: about 70,000, softening point: 100 ° C.) was spray-coated. This coating film contained 50% of a coloring agent and exhibited the characteristics of ΔH = 20 ° C. and Δt = 2 ° C. The leather product was able to select and retain white and blue in a temperature range of 15 ° C to 35 ° C, thus increasing the commercial value.

Example 15 A paint was prepared by using the coloring agent of Example 12 with the same vehicle, composition ratio and manufacturing method as in the example, and 2.8 g of a yellow fluorescent pigment was further added to 100 g of the paint, and the petals of paper-made flowers were spray-painted. This coating contains 66% of colorant, ΔH = 38.7 ° C,
The characteristic was Δt = 8 ° C. The petals could selectively retain red and yellow in the temperature range of 0 to 40 ° C.

Example 16 100 g of leuco dye A (1.0 g), 1,1-bis (4-hydroxyphenyl) cyclohexane (3.0 g) and cetyl benzoate (126.0 g) were added.
It was heated at ℃ for 10 minutes and melted to obtain a paint. This paint was brushed on the surface of the unglazed pottery in a molten state. The coating is ΔH = 12.7
The characteristic was that of ℃ and Δt = 12.4 ℃. The pottery exhibits an orange color at 20 ° C or lower, maintains an orange color in the temperature range of 20 to 35 ° C, and is 38 ° C.
With the above, the color of the unglazed surface was obtained.

Leuco dyes in Examples (electron-donating color-forming organic compounds)
The chemical structure of is:

Leuco dye A: 3-chloro-6 cyclohexylaminofluorane Leuco dye B: 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide Leuco dye C: 2-chloro-3methyl-6- Diethylaminofluorane Leuco Dye D: 2-Dibenzylamino-3methyl-6-diethylaminofluorane Effect of the Invention It is said that the coating composition of the present invention can select and maintain two different colors in a specific temperature range including a normal temperature range. It provides a coating film with useful properties not found in conventional paints,
It is applied to the decoration of three-dimensional objects with variable surface color, irreversible temperature paint that can be used repeatedly, variable recording display, etc., and can add added value such as decorativeness, fun, and fashionability to the object to be coated.

[Brief description of drawings]

FIG. 1 is a graph showing hysteresis characteristics in a color density-temperature curve of a temperature-dependent color memory material. T ₁ …… Full color temperature T ₂ …… Minimum holding temperature T ₃ …… Maximum holding temperature T ₄ …… Coloring and erasing branch temperature

Claims (1)

[Claims] 1. Regarding a color density-temperature curve, a hysteresis width of 5 ° C. to 80 ° C., a Δt value of 1 ° C. to 30 ° C. (difference between color development / decoloration branching temperature and maximum holding temperature) and a holding temperature range are in a normal temperature range. A quasi-reversible thermochromic composition having certain characteristics is used in a nonvolatile content of 1 to 10
A color memory paint containing 0% by weight, wherein the quasi-reversible thermochromic composition is (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) the above two. Is a compatible solution containing three components of a medium organic compound that determines the occurrence temperature of the color reaction, wherein the medium organic compound is (1) a carboxylic acid ester containing a substituted aromatic ring in the molecule, and (2) an unsubstituted aromatic compound. An ester of a carboxylic acid containing a ring and an aliphatic alcohol having 10 or more carbon atoms, (3) a carboxylic acid ester containing a cycloalkyl group in the molecule, (4) an ester of a fatty acid having 6 or more carbon atoms and an unsubstituted aromatic alcohol, (5) Ester of fatty acid having 8 or more carbon atoms and branched aliphatic alcohol, (6)
A color memory paint which is an ester compound selected from the group consisting of diesters of a dicarboxylic acid and an aromatic alcohol or a branched aliphatic alcohol.