JPS6367839B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thermoreversible color-changing composition that has excellent applicability in various industries. Conventionally, substances that exhibit reversible color changes used in various fields for temperature-sensitive display include:
For example, double salts of mercury iodide and aco complex salts of cobalt/nickel halides and urotropin are known. However, these substances have drawbacks such as lack of color selectivity, toxicity, and lack of arbitrary color change temperature, resulting in a significantly narrow range of application. Recently, the color component is an electron-donating color pigment that is normally colorless, and a color developer that causes coloration by accepting the electrons, such as attapulgite, kaolin clay, zinc chloride, and phenol. When contacting and mixing electron acceptors such as phenolic resin oligomers, zinc salicylate, aluminum benzoate, etc., so-called desensitizers, such as polyglycols, which are substances that permanently or temporarily interfere with coloring ability, are used. A large amount of non-volatile solvents such as quaternary ammonium salts and nonionic surfactants as well as alcohols, esters, ketones, acid amides, etc. are used to coexist, and the electron A method is known in which the solubility of either a color-donating dye or a color developer is made dependent on temperature to cause color development and decolorization to occur reversibly. However, the performance of thermochromic materials obtained by the temporary desensitizing effects of these conventional solvents has many drawbacks. That is, these solvents cannot exhibit the desired desensitizing effect unless they are used in extremely large amounts, and as a result, the color density that can be displayed is severely limited. However, if the encapsulation treatment of the component is carried out as a preventive measure, it has the disadvantage of impairing the physical properties of the encapsulation itself. Naturally, this has the disadvantage that it is difficult to obtain a desensitizing effect to complete colorlessness, and that the material exhibits an undesirable residual color or no longer exhibits any discoloration. Therefore, conventional heat-sensitive color-changing materials using these desensitizers have significant weaknesses in their durability, particularly in their durability against solvents, heat, washing, etc. In view of the shortcomings of such conventional thermoreversible color-changing compositions, the present inventors have discovered that if a hardly volatile primary amine salt of carboxylic acid is used in place of these, an excellent desensitizing effect can be achieved with a small amount. Discover new things that you can do,
They have now completed the composition of the present invention, which reversibly and reliably cycles between rich color and colorless color upon temperature changes, and have thus succeeded in completely eliminating the drawbacks of conventional products. Next, the configuration of the present invention will be explained in detail. The structure of the present invention includes an electron-donating color-forming dye, an electron acceptor corresponding to the electron-donating color-forming dye, and the following formula: R-(COOH)x・R'-( _NH2 )y...() where R and R' represent an atomic group of an aliphatic residue, a substituted aliphatic residue, an aromatic residue, a substituted aromatic residue, or a heterocyclic residue, and x and y are integers of 1 or more. , and the isoelectrically the same number of -COOH and -NH ₂ ). It is a color-changing composition. Examples of the electron-donating color pigments that are the color components of the present invention include 3,3' dimethoxyfluorane (yellow), 3-chloro,6-phenylaminofluorane (yellow-orange),
3.diethylamino.6methyl.7 chlorofluorane (vermilion), 3.diethyl 7.8 benzofluorane (peach), 3.3'.3'' tris(p dimethylaminophenyl) phthalide (purple blue), 3.3 'Substituted phenylmethanes and fluorans such as bis(p dimethylaminophenyl) phthalide (green), 3-diethylamino-6-methyl-7-phenylaminofluorane (black), and various indolyl phthalides or spiropyran, Examples include coumarins,
In the present invention, one type or a combination of two or more of these is used. Next, as an electron acceptor that binds to the electron-donating coloring dye to develop a color, phenols such as p-phenylphenol, bisphenol A, cresol, resorcinol, chloroglycine, phenolic resin oligomer, β-naphthol, etc. and their metal salts, ammonium salts, benzotriazoles such as 5-chlorobenzotriazole, 4-laurylaminosulfobenzotriazole, 5-butylbenzotriazole, dibenzotriazole, 2oxybenzotriazole, 5-carboethoxybenzotriazole, and the like; Examples include metal salts and ammonium salts, and in the present invention, one or more of these are used. Next, the poorly water-soluble carboxylic acid primary amine salts, which are components to be made to coexist with the electron-donating color-forming dye of the present invention and the corresponding electron acceptor, are added to the ()
If expressed in a different formula, R-(COO)x・R'-(NH ₃ )y
...(), and both formulas () and () are in a mutually balanced relationship. Therefore, either formula () or () may be used, but the salt corresponds to the desired structure. The former is more convenient because it can be obtained by the reaction of a carboxylic acid and a primary amine. Incidentally, if these carboxylic acids are listed, the aliphatic carboxylic acids include caprylic acid, capric acid, lauric acid, myristic acid, stearic acid,
12 Oxystearic acid, palmitic acid, myristic acid, linoleic acid, linolenic acid, oleic acid, behenic acid, enanthic acid, sebacic acid, azelaic acid, etc., and aromatic carboxylic acids include benzoic acid, p-chlorobenzoic acid, etc. acid, p-butylbenzoic acid, 1-naphthalenecarboxylic acid, cinnamic acid, phenylacetic acid, methacrylic acid, terephthalic acid, 2furancarboxylic acid, 2benzofurancarboxylic acid, cinchoninic acid, and the like. On the other hand, if the primary amines that react with these carboxylic acids are listed, the aliphatic primary amines include caprylamine, laurylamine, myristylamine, stearylamine, coconut amine, oleic amine, hexamethylene diamine, etc. Examples of aromatic amines include butylaniline, chloroaniline, aniline, naphthylamine, phenylenediamine, dichlorbenzidine, aminothiazole, aminopyridine, and the like. Conventionally, it was completely unthinkable in the art to use such amines as a solvent in a thermochromic material, but in the present invention, the permanent desensitizing ability of these amines is utilized, and on the other hand, carbon An extremely significant feature of the present invention is that it is neutralized with an acid. Incidentally, methods using aliphatic carboxylic acids as desensitizers have been known, but these have the disadvantage of significantly lowering color density and are not practical. The poorly water-soluble salt represented by the formula () in the present invention has the following characteristics as an essential component of a thermoreversibly color-changing composition. (1) Carboxylic acids and amines exist in extremely large numbers, and therefore there are many types of salts based on combinations of these, and salts with any melting point, softening point, or freezing point can be prepared. (2) These generally exhibit neutral to weak basicity at room temperature, and have the property of dissociating and increasing basicity when heated. Therefore, these have a complete desensitizing ability similar to that of amines themselves, and are fully effective even in small amounts. (3) Since it has antioxidant properties, it can be expected to effectively protect the pigments mentioned above, which have extremely poor light resistance, and increase their durability. (4) It has a colorless appearance and is hardly volatile. The reason why lower aliphatic bodies can be commonly excluded from the above carboxylic acids and primary amines is as follows.
This is due to the fact that these salts are unstable, showing considerable water solubility and volatility. Moreover, the reason why it is limited to primary amines is that other amines are difficult to exhibit the above effect. In the composition of the present invention, the carboxylic acid primary amines having the above-mentioned characteristics reversibly develops color with heat,
Desensitization and discoloration are considered to be due to the dissolution behavior of the electron-donating color-forming dye or electron acceptor above the softening point or melting point or below the freezing point, that is, due to the dissociation of the two, but the table shows , which shows examples of the melting temperature and specific discoloration temperature of these poorly water-soluble salts. In addition, the color change temperature in this table is the blue color in each reversible color change composition containing 4 parts by weight of crystal violet lactone as an electron donor coloring dye, 20 parts by weight of bisphenol A as an electron acceptor, and 80 parts by weight of each salt. is the temperature at which the color disappears.

【table】

[Table] In the present invention, the selection of the poorly water-soluble salts controls the substantial reversible discoloration, and those with a low melting point generally cause a discoloration phenomenon at a lower temperature than those with a higher melting point. However, in practice, it is possible to set the desired temperature within the living temperature range of about -40°C to 60°C. The thermoreversible color-changing composition of the present invention is composed of three components simultaneously coexisting: an electron-donating coloring dye, an electron acceptor, and a poorly water-soluble carboxylic acid primary amine salt represented by the formula (). However, these are used as mixed solutions, emulsions, dispersions, capsules, etc. Therefore, there are no particular limitations on the encapsulation method or membrane material for the capsule, and various types of additives may be added to the coexistence system or the medium containing the coexistence system, if necessary. Agents, such as surfactants, dryness regulators, antifoaming agents,
Resins, crosslinking agents, catalysts, viscosity modifiers, solvents, dyes, pigments, fluorescent whitening agents, ultraviolet absorbers, ultraviolet stabilizers, infrared absorbers, extender pigments, foaming agents, water repellents, metal powders, glass Balls, plastic spheres, wax, oils and fats, antioxidants, anti-reduction agents, electrolytes, reducing agents, oxidizing agents, acids, alkalis, preservatives, chelating agents, dye carriers, fragrances, etc. may be appropriately added.
This does not depart from the spirit of the invention. When using the thermoreversibly color-changing composition of the present invention, for example, in the case of printing, the composition is dissolved, emulsified or incorporated into the ink vehicle as a capsule encapsulation, and then used for gravure, offset, flexo printing, etc. It can be applied onto the substrate using a known printing method such as screen printing, and thus the paper can be printed. Any thermoreversible discoloration pattern can be displayed on synthetic resin films, glass, ceramics, leather, metals, etc. Similarly, it can be used in textile printing, transfer printing, and paints by adding it to the printing ink vehicle. Through processing, this display can be made on fabrics and other materials as well. On the other hand, the composition of the present invention can be optionally blended with waxes, synthetic resins, soaps, etc., or used together with the above-mentioned printed film, to obtain thermoreversibly discolored molded products. Next, the effects of the present invention will be listed. (1) Since the composition of the present invention has excellent color erasing properties during desensitization, the change from colorless to colored is remarkable. (2) There are many types of poorly water-soluble carboxylic acid primary amine salts used in the present invention, and by selecting one of them, thermoreversible discoloration at any desired discoloration temperature can be determined. (3) The poorly water-soluble salts used in the present invention easily dissolve many of the phenols and triazoles that are electron acceptors and the electron-donating coloring pigments, and only a small amount is required, so that they are durable including the inner capsule. It becomes possible to obtain a thermoreversibly color-changing material with good properties. (4) If the poorly water-soluble salts used in the present invention are used in combination with a conventional solvent, the amount used can be reduced, making it economical and improving the desensitizing effect. Example 1 Ethocel #100 (trade name) 10 parts by weight (hereinafter, parts by weight are abbreviated as parts), 75 parts of ethyl alcohol, 0.3 parts of crystal violet lactone, 14 parts of myristic acid/octylamine equimolar salt, and bisphenol. A colorless and transparent paint ink consisting of 0.7 parts of A was prepared, and coated on the entire surface of clay coated paper (52 g/m ² ) with a coating weight of 5 g/m ² using an air knife coater and dried. The coaching paper exhibits a bright blue color at temperatures below 25°C and becomes colorless at temperatures above 33°C, and is reversible and can be repeated over and over again. It could be used for temperature detection labels, etc. In addition, in the above paint formulation, if 72 parts of ethyl alcohol and 3 parts of Glow Pink MFB powder (trade name of daylight fluorescent pigment) are used, the paint will similarly exhibit a bright pink color above 33°C and a bright purple color below 25°C. , can be caused to exhibit a reversible color change. Example 2 50 parts of malachite green lactone, 20 parts of benzotriazole, 80 parts of bisphenol A, 25 parts of Tinuvin #326 (trade name, ultraviolet absorber), 675 parts of oleic acid/myristylamine equimolar salt, Epicote #828 (trade name) , epoxy resin) was poured into polyvinyl alcohol aqueous solution 1 under stirring to emulsify it into oil droplets with a diameter of approximately 10 to 30 μm.
Add 40 parts of curing agent immediately and heat to 95℃~98℃.
Heating was performed at ℃ for 2 hours to obtain spherical particles with an average diameter of 15 to 35μ. Next, 30 parts of the spherical particles, Binder L (trade name,
A textile printing ink was prepared by uniformly mixing 64 parts of pigment resin textile printing adhesive, 4 parts of Fixer F (trade name, crosslinking agent), 1 part of ammonium chloride, and 1 part of ethylene glycol. The ink was screen printed on a white cotton sateen fabric using a polka dot screen screen (70 meshes) and heat treated at 110°C for 3 minutes. Thus, although the cotton sateen cloth is colorless at temperatures above 10°C,
At temperatures below 3°C, a print with reversible color in which a bright green polka dot pattern appeared was obtained. The general color fastness of the printed pattern is generally grade 4 or higher, and has sufficient durability. Therefore, the printed fabric can be used for ordinary clothing, especially women's outerwear or underwear. Example 3 On kraft paper (130 g/m ² ), 20 parts of a 25% emulsion polymer with a monomer composition of ethyl acrylate/acrylic acid 9:1, 2 parts of sodium alginate
A printing ink consisting of 5 parts of glycerin, 5 parts of urea, 1 part of silicone antifoaming agent, 1 part of octyl alcohol and 66 parts of water was applied on a knife coater in a layer of 0.2 parts.
A uniform flocked layer is formed by applying rayon short fibers (Bright, 0.5 mm, 1.5 d.) to the entire surface at a rate of 100 to 120 g/m ² using an electrostatic flocking machine. Ta. Next, a printing ink consisting of 20 parts of the spherical particles used in Example 2 and 80 parts of binder 50RL (trade name, adhesive for pigment resin printing) was applied to the entire surface of the flocked layer using a screen plate (80 meshes). ), and was printed so as to penetrate into the inside of the flocked layer, and dried. Next, on the flocked layer, a screen plate (90
Matsuminsol F-23C
Printing ink consisting of 98 parts (trade name, adhesive for Frotzky processing) and 2 parts ammonia water is printed, and then DIAMID powder (trade name, nylon resin powder) is evenly sprinkled on the printed surface. A thermal transfer flocked sheet having an inverted alpha-abed pattern adhesive was obtained by adhering the adhesive and removing the powder released on the non-imprinted surface after drying. Using this sheet, the adhesive was brought into contact with a cotton unit cloth, and heat treatment was performed at 180° C. for 10 seconds using a hot press machine, and the base sheet was peeled off. In this way, the alpha abet characters were transferred onto the cotton knit cloth, which was colorless at temperatures above 10°C, but bright green at temperatures below 3°C. Incidentally, the transfer sheet is effective for imparting one-point designs with temperature detection capability to outer clothing in winter, such as sweatshirts, windbreakers, jogging pants, etc. Example 4 In place of 675 parts of oleic acid/myristylamine equimolar salt in the preparation of spherical particles used in Example 2, 675 parts of oleic acid/stearylamine equimolar salt was used.
25 spherical particles were prepared.
25 parts of stearic acid and 50 parts of paraffin wax (40°C) were uniformly melted by heating, poured into a rod-shaped mold, and cooled to obtain a bright green solid colorant.
The solid coloring material can provide any pattern on the paper surface, and the color disappears at temperatures above 33°C. Such color-reversible solid colorants are useful as marking materials for children's drawings such as crayons and passes, and for detecting heat generation in machinery. Example 5 Similar spherical particles were prepared by replacing the equimolar lauric acid/octylamine salt and crystal violet lactone with the equimolar oleic acid/myristylamine salt and malachite glycone lactone in Example 2, and 10 parts of the particles, Sumikasen G804
(trade name, polyethylene resin pellets) was mixed to obtain a bright blue container that could be injection molded at 120°C. When hot water of 43℃ or above is poured into the container, it instantly becomes colorless, and when cold water is poured into the container, it becomes bright blue again and repeats this process reversibly over and over again, making it useful as a pot, tableware such as wash basins, and bath utensils. It is. Example 6 35.5 parts of a 10% polyvinyl alcohol aqueous solution, 2 parts of Redd DCF (trade name, fluoran blue-red pressure-sensitive copying dye), stearic acid/octylamine salt
12 parts and 6 parts of paracumylphenol were added and finely dispersed using a ball mill. Next, 30 parts of a 10% carboxymethylcellulose aqueous solution is added thereto as an aqueous glue solution that is incompatible with the polyvinyl alcohol and stirred for a while to separate the two phases. Add 10 parts of a 20% aqueous solution of industrial tannic acid to the two phases, and after about 1 minute while stirring, immediately add 4 parts of common salt and 0.5 borax.
The red particles were coagulated by adding 50% and stirring, and the next day, diluted with saturated saline, removing only the blue particles by decantation, and then solidifying them under acidic conditions.
The particles were cured with 5 parts of glutaraldehyde, washed with water, and dried. Thus, the red particles had a diameter of about 0.05-0.1 mm and were colorless above 48°C, but turned bright red below 35°C, and this process was repeated reversibly over and over again. As a comparative example, when stearic acid or octylamine was used instead of the stearic acid/octylamine salt used in this example, the former had almost no color and particles with a pale red tinge were obtained.
The latter is consistently completely colorless and no particles are obtained;
In both cases, there were significant differences from this example. on the other hand,
Similarly, when the same amount of stearyl alcohol is used in place of the above salt and the same amount of stearyl alcohol is used as in this example, the resulting red particles exhibit reversibility, but the concentration is about 1/2 that of this example. , and the color disappeared at temperatures above 54°C, but it was difficult to become completely colorless. In addition, the red particles obtained in this example are coated on a metallized film with an ink mixed with a polyacrylic acid ester emulsion, and then cut into strips or threads. It has a temperature-sensitive property that alternates between red and colorless, making it suitable for a variety of uses. Example 7 A printing ink prepared by mixing 20 parts of the spherical particles obtained in Example 5 with 5 parts of Ethocel #100, 10 parts of vinyl acetate/ethylene copolymer resin, and 65 parts of xylol was applied to an animal silhouette pattern gravure plate (80, 100 mm). Using,
It was printed on a polypropylene transparent film (0.085 mm) and dried. Next, the non-printing side of the film is electrostatically attached to the surface of a container-shaped mold, and
Noblen Y-101 (trade name, polypropylene resin) was injected under pressure and heat to obtain an integrally molded product of the film. In this way, a polypropylene container with an animal silhouette pattern was obtained which was colorless above 43°C and turned bright blue below 36°C. Note that vinyl chloride,
It is also possible to obtain a similar molded product using polyethylene or polyester. Example 8 5 parts of the spherical particles of Example 5 and 95 parts of crushed soap base material containing fragrance were mixed uniformly, and then optionally stamped into an animal shape to obtain a decorative soap for children. . The soap is blue at room temperature, and becomes colorless when immersed in hot water of 43°C or higher, but when taken out and poured with cold water, it becomes blue again, and this process can be repeated as many times as needed.

Claims (1)

[Scope of Claims] 1. An electron-donating color-forming dye, an electron acceptor corresponding to the electron-donating color-forming dye, and the following formula R-(COOH)x・R'-(NH ₂ )y (wherein, R and R' represent an atomic group of an aliphatic residue, a substituted aliphatic residue, an aromatic residue, a substituted aromatic residue, or a heterocyclic residue, x and y are integers of 1 or more, and - A thermoreversible color-changing composition characterized by the coexistence of three components of poorly water-soluble carboxylic acid primary amine salts represented by COOH and -NH ₂ in isoelectrically the same number. thing.