JPS6228990B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoreversible color-changing ink composition which is novel and has great industrial applicability.

As is known in the art, there are certain substances that are colorless at a certain temperature, but change color when an appropriate temperature is applied, making it possible to recognize the color, or substances that are colored at room temperature but disappear when heated to high temperatures. Printing inks, paints, etc. are prepared using specific substances that change color or change color, that is, specific substances that exhibit a thermochromic phenomenon, and are used to create paper, fabrics, synthetic resin moldings, ceramics, etc.
It was used for various applications requiring temperature-sensitive display, such as for woodwork.

Such a specific substance or a similar substance that exhibits the above effect is one that first releases moisture and changes color when heated, and then absorbs moisture again and restores color when cooled.
There are double salts of transition metal salts such as cobalt, nickel, and manganese and aminic amides such as hexamethylenetetramine, as well as mercury iodide, complex salts of mercury iodide and other iodide metal salts, and chromic acid. Heavy metal compounds such as lead, ammonium metavanadate, etc.
Changes in molecular arrangement, such as organic compounds such as dixanetyrene and bianthrone, and some organic dyes and pigments, which change color due to crystal transition, steric hindrance, and free radical generation due to heat, and a group of substances called liquid crystals. In addition, substances that strongly color only in acidic or alkaline systems, such as those that coexist with general ionic pigments and acidic or alkaline substances, and change the solubility of the solvent in response to temperature differences. Examples include those in which the former two are reversibly combined.

By the way, among the above-mentioned substances, they have excellent effects as ordinary printed matter or textiles, and are characterized by (a) diversity and optionality of coloration, (b) ability to arbitrarily adjust the color change temperature, and (c) incorporation into ink. What satisfies various conditions such as economical efficiency such as compounding concentration is a 3-component mixture of an acid color developing substance, an acidic substance, and a solvent, which corresponds to the 3-component mixture listed at the end of the above substances. it is conceivable that.

By the way, the mixture exhibits its function only when the three constituent components are always in coexistence, and the absolute reason for the mixture to exhibit its effect is to never be in a state where any one component decreases. It is a condition.

However, in reality, it is extremely difficult to make these three components coexist completely, and all components are physically easily eluted and evaporated out of the system, while other discoloration inhibiting substances may also enter the system. In particular, the effects of other solvents are the most significant, and both of these phenomena become more noticeable during heating.Therefore, today,
These three components must be included in various resin films, but the inclusions themselves do not necessarily satisfy stability. Firstly, although there are various methods of obtaining inclusions, it is almost impossible to completely encapsulate the mixture, and if a large excess of film-forming resin is used, The relative weight ratio of the three components decreases, resulting in a marked drop in color concentration. On the other hand, if large particles are used to improve this, the color concentration becomes spotty, which in any case impairs printability or application effect. This causes the inconvenience of harm.

Second, any of the three components tends to pass through the membrane and be lost during the encapsulation operation, and no single resin is known that completely prevents this. Thirdly, the solvents, surfactants, plasticizers, etc. that are often used in printing inks containing the inclusions easily destroy the inclusions. Fourth, the encapsulated solvent expands in volume during heating and increases the internal pressure, causing it to deviate from the membrane pores.

Printing and coating using thermoreversible color-changing ink compositions using these three components up to now have to be carried out under extremely unstable conditions, and for example, non-solvent resins such as epoxy Used by mixing with
Moreover, it is subject to major restrictions such as avoiding heat drying.

In view of such conventional shortcomings, the present inventor conducted various studies and found that (1) the above three components were not made into complicated and ineffective inclusions, but instead were made into a simple solid solution of non-thermoplastic resin; (2) ), by further coating the solid solution with a hydrophilic polymer compound, the stability is improved at once, and by using the coated thermochromic granules, almost all kinds of coatings such as printing inks can be prepared. They have discovered that it is possible to do this, and that extremely excellent printed matter can be obtained using it, and have thus completed the present invention.

Next, the configuration of the present invention will be explained in detail.

The present invention is a temperature-sensitive thermosensitive material made by forming a solid solution of three components consisting of an acid developer, an acidic substance, and a solvent into a non-thermoplastic resin, and then coating the granules of the solid solution with a film of a hydrophilic polymer compound. A thermoplastic color-changing ink composition characterized by containing color-changing particulate matter.

The acid color developing substance used in the present invention is one that exhibits a reversible phenomenon of color change or decoloration by deacidification after color development with the acid, and 3,6 bisdiethylamino orthocarboxylphate. Enylxanthenelactam, 3-diethylamino-7,8-benzo-orthocarboxyphenylxanelactam,
Red like 3-diethylamino, 7-chlor, orthocarboxyphenylxanthenelactam, etc.
A xanthene substance that develops an orange-red color, 4,4 bis dimethylamino diphenyl/orthocarboxyphenyl methanlactam, 4,4 bis dimethylamino diphenyl/orthocarboxy phenyl methan lactam, 4,4 bis dimethylamino diphenyl・These include phthalide-based substances that develop a purple to blue color, such as paradimethylamino-orthocarboxyfermethane lagtam, and substances that develop a yellow color, such as 3,6-diethoxyfluorane. With the recent development of pressure-sensitive copying paper, a large number of these substances have been synthesized, and it is possible to almost freely select and obtain a desired hue.

Next, as the acidic substance that develops the color of the substance, triazoles such as dibenzotriazole, 4-laurylaminosulfonylbenzotriazole, 5-butylbenzotriazole, dibutyl 1,2,3-triazoledicarboxylate, bisparahydroxy Hydroxyl group-containing substances such as phenylmethane, methyl β-oxynaphthoate, phenol formaldehyde initial condensate, organic acids such as stearic acid, anthracenecarboxylic acid, phytic acid, or toluidine anthranilate, ammonium stearate, 1 Examples include unstable salts such as (3) acetylbenzotriazole, 1(3) benzoylbenzotriazole, and easily decomposable acid derivatives. Among these, triazole compounds are most preferred in the present invention because of their good durability. shows. By the way, the acidic substance can be mixed with the acid color developing substance or by a heating operation.
They are important components that instantly bring out colors, but they are used alone or in combination, taking into consideration their affinity for solvents, which will be described later.

Next, as the solvent which is the third component of the present invention, alcohols such as cetyl alcohol, dodecyl alcohol, oleyl alcohol, octyl alcohol, etc., acidamides such as stearylamide, acetoacetylanilide, oleylamide, etc., stearic acid glyceride , lanolin, diphenyl phthalate, etc., and isophorone, decalin, naphthalene, etc.
Examples include almost all thermofusible solids such as petroleum, rapeseed oil, wood wax, paraffin wax, etc., or organic compounds that are liquid at room temperature.

The action of the above-mentioned solvent is to rapidly dissolve either the acid color developing substance or the acidic substance at a specific temperature, thereby inhibiting the bond between the two, and the specific temperature is such that the color change occurs. It is thought to correspond to temperature.

Therefore, the selection of the solvent substantially controls reversible discoloration, and generally speaking, a solvent with a low boiling point or a low melting point will cause a discoloration phenomenon at a lower temperature than a solvent with a higher boiling point or melting point. By taking the following points into consideration, in practice, it becomes possible to set desired temperatures ranging from about -40°C to about 200°C.

In the thermoreversible color-changing ink composition of the present invention, first, the three components, an acid color developing substance, an acidic substance, and a solvent, are formed into granules of a solid solution of a non-thermoplastic resin and co-fixed together. The resin used in this case is in the state before the three components are converted into a solid solution.
Because it is a liquid or a fusible solid, it becomes non-thermoplastic under the necessary curing conditions. Examples of such resins include polyurethane resins, epoxy resins, melamine resins, phenolic resins, furan resins, and diallyl resins. Examples include general thermosetting resins such as phthalate resins and epoxy phthalate resins, and polyacrylic acid resins having crosslinked molecules.

In the present invention, the above-mentioned 3 using these resins
Components can be made into a solid solution by mixing monomers or initial condensates before resin curing, or in the case of bifunctional components, one of the components, an acid developer, an acidic substance, and a solvent, followed by known curing. In short, the solid solution is one in which each component is uniformly mixed in a non-thermoplastic resin solid, and is similar to, for example, a fluorescent pigment containing a basic dye in a melamine resin. be.

In addition, granulation of these solid solutions is extremely simple, as it is sufficient to crush or classify the already cured material, or granulate it before or during curing.

The present invention is characterized in that thermochromic granules are used, which are formed by coating the granules with a hydrophilic polymer compound film.

Hydrophilic polymer compounds that form such a coating film include natural polymer compounds such as alginate, carrageenan, pectin, chitosan salt, etc.
Cationized starch, carboxymethyl cellulose,
Semi-synthetic polymer compounds such as carboxymethylated starch, carboxymethylated guar gum, etc., polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid amide, polymaleic acid copolymer, etc., and mixtures thereof can be mentioned, and the necessary performance common to these can be mentioned. contains some additives, such as acids,
It easily coagulates with alkalis, electrolytes, heavy metals, aldehydes, and relatively ionic substances.
In addition, these coagulated films generally have excellent water resistance, solvent resistance, gas permeation resistance, etc., and therefore, as a result of effectively protecting the resin solid solution of the three components, they have not been used conventionally. It surprisingly completely improves the drawbacks of inclusions in the three-component system, and fully exhibits stable thermochromic properties.

Thus, the present invention provides a thermoreversible color-changing ink composition which contains the above-mentioned thermosensitive color-changing granules as a main component, and further contains a resin, a solvent, etc. in consideration of adhesion to fabric etc. as an adherend. is obtained.

In addition, in the ink containing the solid solution consisting of the above-mentioned three components, the hydrophilic polymer compound coating the solid solution, or the coated granules used in the present invention, various chemicals such as surfactants and anti-drying agents may be added as necessary. , resin crosslinking agents, catalysts, thickeners, fragrances, pigments, extender pigments, white pigments, fluorescent whitening agents, ultraviolet absorbers,
Antioxidants, metal soaps, preservatives, etc. may be appropriately added, and such cases do not depart from the gist of the present invention.

The thermoreversible color-changing ink composition of the present invention having the above structure can be used in various printing, textile printing, spraying,
A desired pattern is applied to the adherend by brush strokes, etc., and then volatile components are removed and, if necessary, heat treatment is applied.

In this way, a colored product is obtained which exhibits a thermoreversible color change that is dramatically more stable.

Next, the effects of the present invention will be listed.

(1) Unlike conventional three-component inclusions, the thermochromic granules used in the present invention have extremely excellent solvent resistance, heat resistance, and water resistance, and are not affected by almost any solvent, resin, or other substance. Any ink can be mixed without being exposed to water, and heat drying during printing becomes easy.

(2) The thermoplastic ink composition of the present invention is approximately -40°C
It can be arbitrarily adjusted so that it changes color sharply and in a variety of colors over a wide range of temperatures from ~200°C, and the durability of the colored product is high, greatly expanding its uses.

Next, the present invention will be explained using examples.

Example 1 While heating 100 parts by weight of a 15% gelatin aqueous solution (hereinafter parts by weight is simply referred to as "parts") to 85°C under reflux, 4.4 bisdimethylaminodiphenyl paradimethylamino orthocarboxy 2 parts phenylmethane lactam, 1.5 parts dibenzotriazole
A molten mixture consisting of 30.5 parts of Calcol #20 (trade name), 10 parts of Epikote #828 (trade name), 6 parts of Epicure U (trade name), and 2 parts of Aerosil (trade name) was added with stirring, and the average Diameter 0.05
The stirring speed was adjusted so as to maintain the shape of oil droplets of mm size, and if the stirring was continued for 30 minutes, the oil droplets would harden and become solid solution particles.
Next, the granules are separated using a screen, washed with water, and then air-dried to obtain about 52 parts of pale blue-green granules. 52 parts of such granules were added to Poval #205.
(Product name) 100 parts of 8% aqueous solution, 10 parts of fine aluminum stearate powder, and 12 parts of Demol SS (Product name) are mixed uniformly and stirred. Add 250 parts of carboxymethyl cellulose 10 aqueous solution and stir for about 30 minutes. Then, a two-layer separation occurs in the form of a sea-island structure. Next, 25 parts of a 50% aqueous tannic acid solution was added all at once into the layer, and the mixture was stirred for 5 minutes, so that the sea-island structure separation became clearer and changed to a spotted oil droplet dispersion.
By adding 50 parts of common salt and further adding 5 parts of borax, the oil droplets are dehydrated and become a finely solidified product, and a boric acid crosslinker is formed to form extremely hard granules. The next day, dilute the entire contents with saturated saline, separate with screen gauze, and take out the granules. Approximately 78 to 85
Thermochromic granules coated with polyvinyl alcohol are obtained.

Next, 20 parts of the granules, binder #300D
(Product name, adhesive for pigment resin printing mainly composed of polyacrylic acid ester emulsion and paste containing mineral turpentine) 74 parts, Fixer F (trade name, epoxy crosslinking agent) 5 parts, and catalyst #3000
(trade name, inorganic acid salt) were mixed to prepare an ink composition for textile printing.

Using the ink, on cotton broadcloth,
The print was printed on a 10 mm polka dot screen plate (80 meshes) and heat treated at 100°C for 2 minutes.

In this way, a cotton broad-printed fabric consisting of a pale bluish-green polka dot pattern was obtained, and the pattern rapidly changed to dark blue upon cooling to 8°C to 12°C.
The color decreased again at temperatures above .degree. C. and was repeated reversibly any number of times, and the color fastness of the printed material was also good.

For comparison, (1), Epicoat #828 (trade name) and Epicure U (trade name) were separately added to the granules used in this example by modifying the above manufacturing process. (2) Using both the polyvinyl alcohol coating of this example and the solid solution before forming the so-called inclusions,
Although the same inks were mixed, both suffered significant damage during drying after printing, and the density was reduced to 1/4.
It decreased by ~1/2. Furthermore, these inks did not withstand long-term storage, and showed a marked difference from the granular material of this example.

Example 2 20 parts of the polyvinyl alcohol-coated granules obtained in Example 1, 50 parts of 10% Poval #205, 20 parts of Matsuminzole MR-800 (trade name, polyacrylic acid ester copolymer emulsion), aluminum silicate p- 820 (trade name) 5 parts, glutaraldehyde 3 parts, dibasic sodium phosphate 1 part and Tinuvin #326
(Product Name) 1 part was mixed uniformly to prepare a printing ink.

The ink was applied onto pure white paper (64 g/m ² ) with an applicator at a coverage of 0.5 mil and dried.

In this way, a pale greenish-white pure white paper coating was obtained,
The coating film turns bright red-blue at temperatures between 8°C and 12°C,
It exhibited good reversibility to return to its original state at temperatures above 13°C, and also had excellent light resistance.

Incidentally, when preparing and applying ink in the same manner as described above using granules in which Calcol #20 (trade name) used in the granules of Example 1 was replaced with stearyl alcohol and cetyl alcohol, both of them were coated at room temperature. A deep blue coating was obtained which instantly turned almost colorless at about 55° C. for the former and about 45° C. for the latter, and which could be repeatedly and reversibly operated any number of times.

Example 3 30 parts of the granules used in Example 1, 15 parts of Pandix #5102A (trade name), and butyl celloacetate were placed on a soft vinyl chloride sheet (150μ/2H).
Printing ink consisting of 25 parts of xylol and 30 parts of xylol was printed on a full screen screen plate (60 meshes) and dried. In this way, a robust vinyl chloride full-page print exhibiting reversible discoloration similar to that of Example 1 was obtained.

In place of 4,4 bisdimethylaminodiphenyl, paradimethylamino, orthocarboxyphenyl methanlactam, which is the acid developing substance in the granules of Example 1 used in this example, 3diethylamino, 7 chlor orthocarboxyphenylxanthene lactam is 8°C to 12°C
Upon cooling, a reversible color change from almost colorless to deep red occurred.

Example 4 The solid solution particles of the three-component non-thermoplastic resin used in Example 1 were coated with hydrophilic polymer compounds of gelatin, locust Bingham, sodium alginate, and polyvinyl alcohol, and their gelation Similar thermochromic granules were prepared using glyoxal, borax, zinc salt, and methylol melamine as agents, respectively, and were prepared in Examples 1 to 3.
When printing inks similar to No. 3 were prepared, they all showed good stability, and therefore the printed matter was also remarkably durable.

Claims (1)

[Claims] 1 Consisting of an acid developer, an acidic substance, and a solvent 3
Contains temperature-sensitive color-changing granules made by forming a solid solution of a thermosetting resin or a polyacrylic acid resin having crosslinked molecules as a component, and then coating the granules of the solid solution with a hydrophilic polymer compound film. A thermoreversible color-changing ink composition characterized by: