JPS6315877A - Thermochromic composition - Google Patents

Abstract

PURPOSE:To obtain a thermochromic composition which has excellent color forming characteristics, light resistance, and heat resistance, and can be easily microencapsulated, by mixing an electron-donating color former, a color developer comprising an aromatic carboxylic acid derivative having electron- attractive substituents, and a desensitizing component. CONSTITUTION:An objective thermochromic composition is obtained by mixing an electron-donating color former (A) (e.g., crystal violet lactone), a color developer (B) comprising an aromatic carboxylic acid derivative having at least one electron-attractive substituent at the o- and/or m-position of its aromatic ring (e.g., 2,4-dichlorobenzoic acid or 3-nitrophthalic acid), and a desensitizing component (C) selected from among an alcohol, an ester, a ketone, an ether, a thiol, sulfide, a disulfide, a sulfoxide, a sulfone, an aliphatic carboxylic acid, an acid amide, and a hydrocarbon (e.g., stearyl alcohol).

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to thermochromic compositions.

"Prior Art" Thermochromic compositions containing an electron-donating color former, an electron-accepting color developer, and a desensitizing component for inhibiting the color reaction of both components are well known. Such a composition has the so-called thermochromic property of changing color or discoloring in response to temperature changes, and is therefore useful as a temperature indicator.

As the electron-accepting color developer used in such thermochromic compositions, 1. Generally, metal salts or carboxylic acid metal salts of fγ, nolic compounds, and phenolic compounds are used. However, when a phenol 1-1 compound or a metal salt of a phenolic compound is used as a color developer,
The &; It compound and acid heat treatment or direct 1・1) 1
When exposed to light 1'J month l□: f'1l14-, heat resistance ('I) is not sufficient in terms of light resistance, such as a decrease in color development.On the other hand, When used, the coloring property is better than that of II, SoY-Nol 1-1 compound, and N1kI1)1) Heat I1), Yu1)
It also has excellent optical properties. However, carboxylic acid metal salts generally have strong interfacial disease 1-1, so compositions using this are not recommended. It has the disadvantage that when it is molded and dried, the oak, which has good core material retention properties, is difficult to fit.

Also, JP-A-57-! 1001) No. 5 and JP-A No. 6
0173023 (No. II, helmet 1 colorant p-ri 1
It has been proposed to use various aliphatic and monocarboxylic acids in addition to 1-benzoic acid. At present, the color developing ability is extremely low, and a thermochromic composition of practical level has not been obtained.

[Problems to be Solved by the Invention] In view of the current situation, the present inventors have conducted various studies on color developers for thermochromic compositions, particularly on aromatic carbons M, and have found that the aromatic ring l- By using an aromatic carboxylic acid derivative having an electron-withdrawing substituent at a specific position, it has good color development, excellent light resistance and heat resistance,
Furthermore, the present inventors have discovered that a composition that can be easily microencapsulated can be obtained, and have achieved the present invention.

The present invention provides (al electron-donating color former, (bl at least one electron-withdrawing substitution) N at the 0-position on the aromatic ring and/or
or 4 aromatic carboxylic acid derivatives having m-position, and fcl alni I-) 1 page, esters, ketones,
Ethers, thousandols, sulfides, disulfides]
-, sulfoxides, sulfones, aliphatic carboxylic acids, acid amines F, and hydrocarbons.
1) Prepare the product.

1-Effect 1 The present invention uses the aromatic carboxylic acid derivative as a color developer as described in 1 above. Naphthoic acid, anthrylic acid, etc. are commonly used, but benzoic acid and 1- and nano-1-1-acid are preferably used.

In addition, these compounds are substituted at at least one of the 0-position and the ff1-position relative to the carebonidosyl group of the a) electron-withdrawing 1'l;ll!
/ 10 groups preferably include a methyl group, a cyano group, a cyano group, a cyano group, a cyano group, a cyano group, a cyano group, a cyano group, a methyl group, and a methyl group. Among these, halogen atoms and -
The 1I:J group is more preferable because it provides a color developer with particularly excellent color development.

The aromatic carbonic acid derivative of the present invention has at least one of the following electron-withdrawing substituents (1), but derivatives having two or more electron-withdrawing substituents are preferable (3E). L, <used.

The luponic acid derivatives of the group (n;

Hydroxyl group; Amino group; Carboxyl 75, methyl group, ethyl group, n-propyl group, 1-propyl group, n-butyl group, t-butyl group, n-hexyl group, -octyl group, n-dodecyl group , vinyl group, aryl group, decenyl group, methoxyl/xyethyl group, etc., a saturated or unsaturated linear or branched alkyl group; cyclohexyl group, methylcyclohexyl group, etc. Substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxyl group such as methoxy group, ethoxy group, fluorboxy group, methoxy group, methoxyethoxy group; Hensyl group, halogenated hensyl group, anisyl group group, substituted or unsubstituted aralkyl group such as α-methylbenzyl group; phenyl group, naphthyl group, halogenated phenyl group, halogenated naphthyl group, 21
・Substituted or unsubstituted aryl group such as halogenated phenyl group; 16 such as phenoxy group, triloxy group, naphthoxy group, halogenated naphthoxy group, methoxydiphenoxy group, etc.
Substituted or unsubstituted aryloxy group; methonitosicalone 1ζnyl group, phyllocarbonyl group, pheno-1-
Lame 1-1 - Substitution or absence of dicarbonyl group; 6
Carbonyl: J 4-dicarbonyl group; phenoxycarbonyl group, triloxycarbonyl group, methoxypheno-1
- Substituted or unsubstituted ary-1 such as dicarbonyl group
-to-1-dicarbonyl 21 to ace-1-ami1',! ^,
benzoyl terimino group, methoxy-1 cetamine 1 S,
l゛: 6-substituted acylamino group; 7-substituted acylamino group;
N f-nodocarba: 1': iJ group, N,N-diethylcarba-[yl group, N-(4-methoxy-n-butyl)carba-[yl]! I (replacement of nato゛ or = 1
i7ta carleva drying/fl), V i N-sotylsulfamoyl-dodecylsulfuryl, (, N-(4-methoxy-n-butyl)sulfa: substituted or unsubstituted sulfoyl group such as [yl group) Substituted or unsubstituted sulpo-S-ylamino, such as methoxymethylsulfonylamino group, etc.

Aromatic carbon #Ifg as described above used in the present invention
B1. Among these, phthalic acid, terephthalic acid, phthalic acid monoester, and terephthalic acid monoester, which have two or more halogen atoms and/or nitro groups on the aromatic ring, are particularly preferably used because of their extremely excellent color developing ability. Ru.

In the present invention, a specific aromatic carboxylic acid derivative is used as 2f! The above may be used in combination, and if necessary, a color developer known in the art may also be used in combination.

As the electron-donating coloring agent used in the present invention,
Compounds known in the field of thermochromic compositions can be used, including, but not limited to, the following.

3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3- (1. 2-dimethylindole-3-
yl) phthalide, 3,3-bis(9-ethylcarbazol-3-yl)-6-dimethyl)'minophthalide, 3-
p-dimethylaminophenyl: 1 (1 methylpyrrol-3-yl) -6-dimethylaminophthalide and other triallylmethane dyes, 4,4'-bis-dimethyl, mininobenzhi 1: lylbenzyl ether, N- Diphenylmethane-based dyes such as lophenylene blue, p-2i +:r <Nzoyl [1 Thiazine-based dyes such as icomethylene blue, etc.1,3 Methyl-spiro-dinaphthopyran, 3.
- Spiro dyes such as phenylruthubi-1'1-dinaphthopyran and 3-benzyl-spiro-dinaphthopyran; lactam dyes such as rhodamine-13-anilinolactam, rhodamine (p-nitroanilino) lactam, and rhodamine (0-chloroanilino) lactam; 3-dimethylamino-7-medoxyfluorane, 3-diethylamino-1-
Chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-(N-ethyl-p~toluidino)
-7-Methylfluorane, 3-diethylamino-'l-N-acetyl-N-methylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-N-chloroethyl-N-methylaminofluoran Orane, 3-(N-ethyl-p-toluidino)-
6-Methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-phenylaminofluorane, i(N-cyclohexyl-N~methylamino)-6
-Methyl-7-phenylaminofluorane, 3-pyrrolidino-6-methyl-7-phenylaminofluorane, 3
Fluoran dyes such as -piperidino-6-methyl-7-phenylaminofluorane and 3-diethylamino-6-methyl-7-xylidinofluorane.

In the thermochromic composition of the present invention, alcohols, esters, ketones, ethers, thiols, sulfides, disulfides, sulfoxides, sulfones, aliphatic carboxylic acids, acid amides, hydrocarbons, etc. At least one compound selected from the group consisting of is used as a desensitizing component.

Such alcohols tr+ and G7 include n-octyl alcohol, n-nonyl alcohol, n-decyl alcohol, n-sefyl alcohol, n-stearyl alcohol, 1 syl alcohol,
n-F cosyl alcohol: l-l, n-mericyl alcohol, isocetyl alni-l, isostearyl alcohol, isodo-J syl alcohol, oleyl alcohol,
cyclohexylnol, cyclopentanol, hexyl alcohol, cinnamyl alcohol, ethylene glycol, dicol f-lene gelicol, triethylene glycol, polyethylene glycol, propylene glycol -l, sol, lengericol, hexylene glycol, Schiff's 1; 1-zan-1,4-diol, 1-l-propane, 1,2,6-hexane I diol , Pentaerythrit, Turpino I.
Manniso I. Tokaal.

As esters, G1), zo'1) octyl onate,
Amyl caproate, amyl caprylate, octyl caprate, hexyl laurate, octyl laurate, dodecyl laurate, myristyl laurate, cetyl laurate, stearyl laurate, ocdyl myristate,
Lauryl myristate, myristyl myristate, stearyl myristate, ethyl palmitate, octyl valmitate, lauryl valmitate, myristic palmitate, cetyl palmitate, stearyl palmitate, butyl stearate, lauryl stearate, myristyl stearate, stearic acid Cetyl, stearyl stearate, propyl hehenylate, butyl hehenylate,
Amyl benzoate, phenyl benzoate, butyl oleate,
Examples include dibutyl malonate, dibutyl cehatate, dioctyl phthalate, diotyl phthalate, dibutyl maleate, and the like.

Ketones include methylhexylketone, diacetone alcohol, mesityl oxide, cyclohexanone, methylcyclohexanone, acetophenone, propiophenone, hensifenone, 2.

Examples include 4-pentanedione, ace1-nylacetone, and ketone wax.

Examples of ethers include he-1-syl ether, diisopropylhenzylconite, diphenyl ether dioxane, ethylene glycyl 1-yl dibutyl ether, diethylene glycyl dibutyl ether, and ethylene glycyl ml.
-) Regift, Nyl ether glycol monophenyl ether, etc. can be exemplified.

Examples of thiols include n-myristyl mercaptan,
r)-=su-allyl mercaptan, isododecyl mercaptan, isocetyl mercaptan, dodecylbenzyl mercaptan, and the like.

As for sulfides, "C" is di-r1-decyl sulfide, di-n-1' decyl sulfide, di-n-myristyl sulfide, di-n-cetyl sulfide, di-n-stearyl sulfide, octyldodecyl sulfide, di Tolylsulfondo, diethyl phenyl sulfide 1", 4
．． Examples include 4-dichlorodiphenyl sulfide.

Examples of disulfides include di-n-dodecyl disulfide, di-n-myristyl disulfide, di-n-stearyl disulfide, and ditolyl disulfide.

Examples of sulfoxides include tetramethylene sulfoxide, diphenyl sulfoxide, and dibenzyl sulfoxide.

Examples of sulfones include ditolyl sulfone, ditolyl sulfone, dibutylphenyl sulfone, dibenzyl sulfone, 4. Examples include 4-dichlorodiphenylsulfone.

Examples of aliphatic carboxylic acids include caproic acid, caprylic acid,
Capric acid, uric acid, myristic acid, valmitic acid, stearic acid, araxic acid, behenic acid, lignoceric acid, cerotic acid, partoleic acid, oleic acid, ricinoleic acid, linoleic acid, lilunic acid, eleostearic acid, eruca Examples include acids.

As acid amides, caprylic acid amide, capric acid amide, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide 1
', oleic acid amide, henzamide, etc.

Examples of hydrocarbons include bis-(α-methylbenzyl)benzene, diisopropylnaphthalene, dibenzylbenzene, propylnaphthalene, cyclohexane, methylcyclo1-1henyline, 1. l,3-trimethyl-3
- Phenylindane and the like.

The thermochromic &;It composition of the present invention contains an electron-donating coloring agent as described above, a color developer consisting of a specific 'A aromatic carboxylic acid derivative, and a desensitizing component. The proportion of each component in the composition is expressed by weight, generally in liters.
:0. It is adjusted in the range of l to too: o, about s to 500, more preferably l:o, about 5 to 50; l to 200.

It should be noted that if the amount of the color developer is too large, the reversible discoloration property, especially the color erasing property, will be deteriorated, and conversely, if the amount of the color developer is insufficient, the color density will be low. Furthermore, if the amount of the desensitizer is too large, the coloring density will be low, whereas if it is insufficient, the color erasing property will be reduced.

The thermochromic composition of the present invention is generally prepared by heating and melting a color forming agent, a color developer, and a desensitizing component, mixing the mixture, and then cooling it, or by dissolving it in an appropriate solvent and then removing the solvent. be done. In addition, pigments, fillers, ultraviolet absorbers, sensitizers, antioxidants, etc. may be added to the thermochromic composition as necessary.

Note that the composition of the present invention can also be used after being microencapsulated and powdered. Encapsulation techniques that can be used in the present invention include the known interfacial polymerization method, 1n-situ method, coacervation method, spray drying method, etc. In particular, melamine-formaldehyde described in JP-A-53-84881 etc. Capsules whose walls are made of resin are particularly preferred because capsules with excellent solvent resistance can be obtained.

Furthermore, the thermochromic composition of the present invention and its encapsulated product can be homogeneously incorporated into a polymer to form a thermochromic polymer, and furthermore, thermochromic printing can be performed by a conventionally known method. It can also be used in addition to ink, thermochromic writing implements, thermochromic paints, thermochromic sheets, thermochromic packaging, etc.

"Examples" The present invention will be described in more detail below with reference to Examples, but the present invention is not limited thereto.

Parts and % in the examples represent parts by weight and % by weight, respectively, unless otherwise specified in I)).

Example 1 1 part of crystal violet lactone (CVL), 2 parts of tetrachloroCl phthalic acid 1,000-isobutyl ester, and 20 parts of stearyl alcohol were heated and melted at 100°C, and then cooled and solidified to obtain a solid. This solid substance was blue at room temperature (20°C), but when heated, when the temperature reached 53°C, the color disappeared and became colorless. Note that this discoloration phenomenon was reversible.

Furthermore, the color development of this solid at room temperature was visually evaluated, and the results were compared to the hue before (20°C) and after discoloration.
It is shown in Table 1 along with the discoloration temperature.

B: Good color development.

C: Color development is slightly inferior, but there is no problem in practical use.

D: Poor color development, causing problems in practical use.

Examples 2 to 23 and Comparative Examples 1 to 4 26 types were prepared in the same manner as in Example 1, except that the color formers, color developers, and desensitizing components shown in Table 1 were used in the numbers shown in Table 1. A thermochromic composition was obtained.

The resulting composition was heated, and the temperature at which discoloration was observed was measured. The results are shown in Table 1 together with the hue before (20° C.) and after discoloration. In addition, color development was evaluated in the same manner as in Example 1, and the results are also listed in Table 1.

In addition, in the color former column of Table 1, 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-phenylaminofluorane is used as PSD-150, and 3-(
N-Ethyl-1)-toluidino)-7-methylfluorane at r! ．． It was abbreviated as TPM.

-18= Example 24 In Example 1, instead of 2 parts of tetrachlorophthalic acid mono-isobutyl ester, 2,4.6-dryiodo 3-? The same procedure as in Example 1 was carried out except that 2 parts of pl aminobenzoic acid was used and 0.5 part of red On material (trade name: F5RK, manufactured by Hoechst) was added. It's I. This composition rapidly turned purple at room temperature (20°C), and turned red when heated and the temperature reached 53°C. In addition, the coloring property of this composition in purple was 1) clear.

Example 25 In Example 1, C, 4 parts of tetrachlorophthalic acid 1,000-isobutyl ester was used instead of 2 parts of tetrachlorophthalic acid 1,000-isobutyl ester, and stearyl al: t
Thermal discoloration 1
'l &nn animals were obtained. This composition is normally IJ1 (20°
(:) exhibited a blue color, and became colorless when heated and the temperature reached 53°C. In addition, the coloring property of this composition in blue was extremely excellent.

Example 26 Heat treatment was carried out in the same manner as in Example 1, except that 2 parts of tetrafluorophthalic acid was used instead of 2 parts of tetrachlorophthalic acid 100-isobutyl ester, and 1 part of titanium oxide was added. A color-changing composition was obtained. This composition exhibits a blue color at room temperature (20°C), and when heated to a temperature of 5°C.
When the temperature reached 3°C, it turned white. In addition, the coloring property of this composition in blue was extremely excellent.

It was good.

Examples 27 to 4 () The coloring agent shown in Table 2, 1"1 coloring agent and desensitizing component,
Example 1 except that each was used for the number of copies shown in Table 2.
Similarly, 14 thermochromic compositions were prepared.

If the resulting composition is solid, heat it, or if it is liquid, cool it, measure the temperature at which discoloration is observed, and compare the results before discoloration (20°C) and before discoloration. The results are shown in Table 2 together with the subsequent hues.

In addition, color development was evaluated in the same manner as in Example 1, and the results are also listed in Table 2.

Example 41 5 parts of crystal hiolesotolactone, 15 parts of tetrachlorophthalic acid mono-isoamyl ester, and 80 parts of stearyl alcohol were heated and melted at 90°C to obtain an internal phase liquid. Ethylene-maleic anhydride copolymer (product name:
IMA-31, manufactured by Monosanto) 3.0% water? 8 liquid 2
Add 20% caustic soda aqueous solution to 00 parts and
1) was set to (j, 0), and the internal phase liquid was emulsified in a solution heated to 80°C to give an average particle size of 7μ, and then the system was heated to 5°C.

Separately, 10 parts of melamine was added to 30 parts of a 37% formaldehyde aqueous solution and reacted at 60° C. for 15 minutes to prepare a prepolymer aqueous solution.

This prepolymer aqueous solution was added dropwise to the emulsion in 1): 1, and 0.5N-hydrochloric acid was added dropwise while stirring to determine the pI]
After adjusting the pH to 5.3, the temperature was heated to 70°C, held at that temperature for 1 hour, the pH was lowered to 4.5 or less with IN-hydrochloric acid, and the temperature was further kept for 3 hours, then allowed to cool to form a blue capsule dispersion. I got it.

The obtained capsule dispersion was coated onto a 4.0 g/% base paper using an air knife coater so that the solid content was 6 g/rrr.

This coated paper was blue at room temperature (20°C), but
When heated to 3°C, the color disappeared. Moreover, this discoloration phenomenon was reversible.

"Effect" As is clear from the results of each Example, all the thermochromic compositions of the present invention had excellent color development.

Patent applicant: Kanzaki Paper Co., Ltd. 26-1

Claims (5)

[Claims] (1) (a) an electron-donating color former, (b) an aromatic carboxylic acid derivative having at least one electron-withdrawing substituent at the o-position and/or m-position on the aromatic ring, and (c)
Alcohols, esters, ketones, ethers, thiols, sulfides, disulfides, sulfoxides, sulfones, aliphatic carboxylic acids, acid amides,
A thermochromic composition comprising a compound selected from the group consisting of hydrocarbons. (2) The thermochromic composition according to claim 1, wherein the electron-withdrawing substituent is a halogen atom, a nitro group, a cyano group, an acyl group, a sulfone group, a sulfonyl group, or a trihalomethyl group. (3) The thermochromic composition according to claim (2), wherein the electron-withdrawing substituent is a halogen atom or a nitro group. (4) The aromatic carboxylic acid derivative is a derivative having two or more electron-withdrawing substituents on the aromatic ring.
Thermochromic composition according to item 1). (5) Claim (4), wherein the aromatic carboxylic acid derivative is phthalic acid, terephthal, phthalic acid monoester, or terephthalic acid monoester having two or more halogen atoms or nitro groups on the aromatic ring. thermochromic composition.