JPH01156695A - Heating time display body - Google Patents

Abstract

PURPOSE:To obtain a display body with which a distinct hue change takes place abruptly when the prescribed time elapses by disposing a layer contg. an electron-donating colorable org. compd. and a layer contg. an electron- accepting org. compd. via a resin layer. CONSTITUTION:The display body is formed by laminating the layer 4 contg. the electron-donating colorable org. compd. and the layer 2 contg. the electron- accepting org. compd. via the resin layer 3. A support 1 may be provided at need to such laminate. The distinct hue change takes place abruptly when the display body formed in such a manner is heated only for the prescribed time at a prescribed temp. and, therefore, a user is able to distinctly judge the lapse of the time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heating time indicator that indicates that a predetermined time has elapsed at a constant temperature.

[Prior art]

Conventionally, as an indicator of heating time, it is known that, for example, a dye that melts, evaporates, or sublimates and fades over time after heating is used (for example, Japanese Patent Publication No. 53-2322
6, Japanese Patent Publication No. 53-23227).

However, with these displays, the color change does not occur suddenly after a predetermined amount of time has elapsed, but rather progresses gradually over time, so it is not possible to clearly display the passage of a predetermined amount of time. . In addition, when heated, the electron-donating coloring property that develops over time is achieved by combining organic compounds and sulfonic acids.
Heating time indicator in which resins having acidic groups such as carboxylic acid and phenolic hydroxyl groups coexist (Japanese Patent Laid-Open No. 54-126
882, JP-A-54-146689), a heating time indicator that combines a layer containing an electron-donating color-forming organic compound as a main component and a layer containing a dye that melts, evaporates, or sublimates over time upon heating (JP-A No. 54-146689); 80-7218) is known. Although these methods all attempt to clarify the hue change over a predetermined period of time, since the hue change does not occur suddenly, it is not possible to clearly determine the passage of time.

[verbal]

An object of the present invention is to solve the drawbacks of conventional heating time indicators, and to provide a heating time indicator in which a clear hue change occurs suddenly when a predetermined time has elapsed, so that it can be clearly determined that the time has elapsed. It's about doing.

〔composition〕

The present inventors have discovered that by inserting a resin layer between an electron-donating color-forming organic compound and a layer of an electron-accepting organic compound that develops color, the color rapidly develops after a certain time when heated at a constant temperature. We have discovered that this phenomenon occurs and have completed the present invention.

That is, the present invention provides a heating time indicator comprising a layer containing an electron-donating color-forming organic compound and a layer containing an electron-accepting compound, and a resin layer is provided between these two layers. It is.

The electron-donating color-forming organic compounds used in the present invention include:
For example, diarylphthalides, polyarylcarbinols, leucouramines, acylouramines,
These include arylauramines, rhodamine B lactams, indolines, spiropyrans, fluorans, diindolylphthalides, arylindolyl phthalides, diindolyl azaphthalides, arylindolyl azaphthalides, and the like.

Specific examples of these compounds include the following compounds.

Crystal violet lactone, malachite green lactone, Michler hitrol, crystal violet carpinol, malachite green carpinol, N
-(2,3-dichlorophenyl)leukoolamine, N
-benzoyluramine, rhodamine B lactam, N-
Acetyl auramine, N-phenyl auramine, 2-(
phenyliminoethanedylidene) 3,3-dimethylindoline, N-3,3-ylimethylindolinobenzospiropyran, 8-methoxy-N-3,3-)limethylindolinobenzos birobilane, 3-diethylamino- 6-
Methyl-7-chlorofluorane, 3-diethylamino-
7-methoxyfluorane, 3-diethylamino-6-benzyloxyfluorane, 1,2-benz-6-diethylaminofluorane, 3゜6-di-p-toluidino-4
, 5 dimethylfluoran-phenylhydrazide-γ-lactam, 3-amino-5-methylfluoran, 2-methyl-3-amino-6-methyl-7-methylfluoran,
2,3-butylene-6-di-n-butylaminofluorane, 3-diethylamino-7-anilinofluorane-3
-diethylamino-7-(balatluidino)-fluorane, 7-acetamino-3-diethylaminofluorane, 2-bromo-6-cyclohexylaminofluorane,
2,7-dichloro-3-methyl-6-n-butylaminofluorane, 3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide, 3-(4-diethylaminophenyl)-3 -(1-ethyl-2-methylindol-3-yl)phthalide, 3-(2-ethoxy-4
-diethylaminophenyl)-3-(1-ethyl-2-
Methylindol-3-yl)-4-azaphthalide, 3
,3-bis(1-n-butyl-2-methylindole-
3-yl)-4-azaphthalide and the like.

Examples of the electron-accepting organic compound used in the present invention include compounds having a phenolic hydroxyl group and metal salts thereof, aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms, carboxylic acid metal salts, acid phosphorus Acid esters and their metal salts, 1,2,3-triazole and its derivatives, thiourea and its derivatives, urea and its derivatives, guanidine and its derivatives, aromatic and aliphatic carboxylic acid anhydrides, boric acid esters, halogenated alcohols,
These include oxazoles, thiazoles, imidazoles, pyrazoles, pyrroles, aromatic sulfonamides, and aromatic sulfonimides.

Compounds containing six phenolic hydroxyl groups include monophenols to polyphenols, and their substituents include alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, and halogens. Examples of these compounds are shown below.

Tertiary-butylphenol, nonylphenol, dodecylphenol, 2,2-methylenebis-(4-methyl-6-tertiarybutylphenol), α-naphthol, β-naphthol, hydroquinone monomethyl ether, guaiacol, eugenol, p-chlorophenol, p- Bromophenol, O-chlorophenol,
0-bromophenol, 0-phenylphenol, p-
Phenylphenol, p-(p-chlorophenyl)-phenol, 0-(o-chlorophenyl)-phenol,
Methyl p-hydroxybenzoate, p-hydroxybenzo6
ethyl acid, propyl p-hydroxybenzoate, n-butyl p-hydroxybenzoate, octyl p-hydroxybenzoate, dodecyl p-hydroxybenzoate, 3-isopropylcatechol, p-ter-butylcatechol,
4,4-methylenediphenol, 4,4-thio-bis-
(6-ter-butyl-3-methylphenol), 1.
1-bis-(4-hydroxyphenyl)-cyclohexane, 4,4-butylidene-bis-(5-ter-butyl-3-methylphenol), bisphenol A, 1.1
-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)hebutane, 1,1-bis(
4-hydroxyphenyl)hexane, 2.2bis(4-
hydroxyphenyl)nonane, 2,2-bis(4-hydroxyphenyl)hexane, 2,2-bis(4-hydroxyphenyl)butane, 3,3-bis(4-hydroxyphenyl)pentane, bisphenol S11.2-di Oxynaphthalene, 2,3-dioxynaphthalene, chlorcatechol, bromocatechol, 2,4-dihydroxybenzophenone, phenolphthalein, O-cresolphthalein, methyl protocatechuate, ethyl protocatechuate, propyl protocatechuate, protocatechuate -octyl acid, dodecyl protocatechuate,
2,4.6-)lyoxymethylbenzene, 2,3.4-
Trioxyethylbenzene, methyl gallate, ethyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, 2,3.5-trioxynaphthalene, tannic acid, phenol There are resins, etc.

As a metal salt of a compound having a phenolic hydroxyl group,
sodium of the compound having a phenolic hydroxyl group;
Potassium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt,
There are metal salts of metals such as tin, copper, iron, vanadium, titanium, lead, and molybdenum.

Aromatic carboxylic acids and aliphatic carboxylic acids having 2 to 5 carbon atoms include maleic acid, fumaric acid, benzoic acid, toluic acid, p-ter-butylbenzoic acid, chlorobenzoic acid, brombenzoic acid, ethoxybenzoic acid, Examples include gallic acid, naphthoic acid, phthalic acid, naphthalene dicarboxylic acid, acetic acid, propionic acid, butyric acid, and valeric acid.

Examples of carboxylic acid metal salts include metal salts of monocarboxylic acids to polycarboxylic acids. Examples of these compounds are shown below.

Acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid,
Capric acid, lauric acid, myristic acid, valmitic acid, stearic acid, isostearic acid, behenic acid, crotonic acid, oleic acid, elaidic acid, linoleic acid, linolic acid, monochloroacetic acid, monobromoacetic acid, monofluoroacetic acid, glycolic acid, hydroxypropion Acid, hydroxyacetic acid, ricinoleic acid, 1,2-hydroxystearic acid, lactic acid, pyruvic acid, oxalic acid, malonic acid, succinic acid,
Adipic acid, cepatic acid, malic acid, tartaric acid, chiracolaic acid, maleic acid, fumaric acid, naphthenic acid, benzoic acid,
Toluic acid, phenylacetic acid, p-ter-butylbenzoic acid, cinnamic acid, chlorobenzoic acid, brobenzoic acid, ethoxybenzoic acid, mandelic acid, protocatechuic acid, vanillic acid, resorcinic acid, dioxybenzoic acid, dioxychlorobenzoic acid, Sodium, potassium, lithium, calcium, zinc, zirconium, such as gallic acid, naphthoic acid, hydroxynaphthoic acid, phthalic acid, phthalic acid monoethyl ester, naphthalene dicarboxylic acid, naphthalene dicarboxylic acid monomethyl ester, trimellitic acid, pyromellitic acid, etc. There are metal salts of metals such as aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium, lead, and molybdenum.

Examples of the acidic phosphate ester compound include ester groups such as alkyl groups, branched alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, aryl groups, and derivatives thereof. Acidic phosphoric acid ester compounds include monoesters and diesters, and may also be mixtures thereof. In the following compounds, the mixture of monoester and diester is called acid phosphate. Examples of acidic phosphate ester compounds are shown below.

Methyl acid phosphate, ethyl acid phosphate, n-propyl acid phosphate, n-butyl acid phosphate, 2-ethylhexyl acid phosphate, n-octyl acid phosphate, isodecyl acid phosphate!・, n-decyl acid phosphate, lauryl acid phosphate, myristyl acid phosphate, cetyl acid phosphate, stearyl acid phosphate, tocodyl acid phosphate, oleyl acid phosphate, 2-chloroethyl acid phosphate, 2,3-dibromo-
2゜3-dichloropropyl acid phosphate, dichloropropyl acid phosphate, cyclohexyl acid phosphate, phenyl acid phosphate,
〇-Tolyl acid phosphate, 2.3-xylyl acid phosphate, p-cumenyl acid phosphate, mesityl acid phosphate, 1-naphthyl acid phosphate, 2-naphthyl acid phosphate, 1-anthryl acid phosphate, benzyl acid phosphate , phenethyl acid phosphate,
Styryl acid phosphate, cinnamia acid phosphate, trityl acid phosphate, phenylmethyl phosphate, phenylethyl phosphate, phenyl n-propyl phosphate, phenyl n-butyl phosphate, phenyl n-octyl phosphate, phenyl lauryl phosphate, phenylcyclohexyl phosphate, phenyl (2,3-xylyl) phosphate, cyclohexyl stearyl phosphate, cyclohexyl cetyl phosphate, dimethyl phosphate, diethyl phosphate, moro-propyl phosphate, dibutyl phosphate, di-n-hexyl phosphate, di(2-ethylhexyl) phosphate, ziraud Decyl phosphate, dilauryl phosphate, simyristyl phosphate, diethyl phosphate, distearyl phosphate, diethyl phosphate, diphenyl phosphate, dicyclohexyl phosphate, di0-tolyl phosphate, bis(diphenylmethyl) phosphate, bis(triphenylmethyl) phosphate, Ji (2
Examples include ゜3-xylyl) phosphate, dibenzyl phosphate, di(1-naphthyl) phosphate, and the like.

Examples of the metal salts of acidic phosphate ester compounds include sodium, potassium, lithium, calcium, zinc, zirconium, aluminum, magnesium, nickel, cobalt, tin, copper, iron, vanadium, titanium,
There are metal salts of metals such as lead and molybdenum.

Examples of triazole compounds include 1,2.3-triazole, 4(5)-hydroxy-1,2°3-triazole, 5(6)-methyl-1.2°3-benzotriazole, 5-chloro-1, 2゜3-benzotriazole, 7-
Nitro-1+ 2゜3-benzotriazole, 4-benzoylamino-1,2,3-benzotriazole, 4-
Hydroxy-1,2,3-benzotriazole, naphtho-1,2,3-triazole, 5,5-bis(1,2,
3-benzotriazole), 1.2.3-benzotriazole-4-sulfooctylamide, and the like.

Thiourea and its derivatives include thiourea, methylthiourea, N,N-diallylthiourea, allylthiourea,
Acetylthiourea, Sym-genylthiourea, Sym
-di0-) Lylthiourea, N,N-dichlorohexylthiourea, N-methyl-N-acetylthiourea, ethylthiourea, N,N-ditetradecylthiourea, 1-phenylthiourea, dimethylolthiourea, diphenyl- Examples include bis-thiourea, diphenyl-p-phenylene-dithiourea, and diphenyl-m-phenylene-dithiourea.

Examples of urea and its derivatives include urea, 1,3-diphenylurea, benzyl urea, N,N-dicyclohexyl urea, 1-allylurea, benzoylurea, and the like.

Guanidine and its derivatives include guanidine, 1,
3-ditolylguanidine%1 0-tolyl biguanide,
Examples include dicatechol borate complexes of 1,3-diphenylguanidine, 1-phenylguanidine, 1,3-diethylguanidine, and di-o-tolylguanidine.

Aromatic and aliphatic carboxylic anhydrides include phthalic anhydride, tetrachlorophthalic anhydride, benzoic anhydride, benzoyl-p-toluenesulfonate, 4-nitrobenzoic anhydride, acetic anhydride, propionic anhydride, and succinic anhydride. acid,
Examples include glutaric anhydride and maleic anhydride.

As the boric acid ester, boric acid-trilotryl,
Triphenyl borate, tri-ro octadecyl borate, tri-ro hexadecyl borate, tri-lo octyl borate, triethyl borate, tri-n-propyl borate, tri-1so-propyl borate, tri-borate -butyl, tri-p-chlorophenyl borate, tri-p-nitrophenyl borate, and the like.

Examples of halogenated alcohols include 2,2゜2-trichloroethanol, 2.2.2-tribromoethanol,
2.2.2-trifluoroethanol, 1.1.1-)
Dichloro-2-methyl-2-propatol, 1.1.1
-Tribromo-2-propatol, 4,4.4-tribromobutanol, 1,3-dichloro-2-propatol, 2.2-bis(bromomethyl)-3-bromo-1-propatol, 2.2 -bis(bromomethyl)-1,3-
Propanediol, N-phenyl-N-(1-hydroxy-2,2゜2-trichloroethyl)thiourea, N-(
Examples include 1-hydroxy-2,2,2-1ribromoethyl)-thioacetamide.

Examples of oxazole include 2-mercaptobenzoxazole, 2-hydroxybenzoxazole, 2-(2-
, 4″-dinitrophenylthio)benzoxazole, and the like.

Examples of thiazoles include 2-mercaptobenzothiazole, 2-hydroxybenzothiazole, 2-(4-morpholinodithio)benzothiazole, benzothiazole 5
．． There are zinc salts of 2-mercaptobenzothiazole and the like.

Examples of imidazoles include benzimidazole, 2-mercaptobenzimidazole, imidazole, 2-hydroxybenzimidazole, 1-ethylbenzimidazole, 2-methylimidazole, 2-heptadecylimidazole, 1-benzyl-2-methylimidazole. etc.

Examples of pyrazoles include pyrazole, 1-ethylpyrazole, benzpyrazole, and 1-hydroxybenzopyrazole.

Examples of the pyrroles include pyrrole, 2,3-dimethylpyrrole, 2-methylpyrrole, benzopyrrole, and 2H-pyrrole.

Aromatic sulfonamides include benzenesulfonamide, benzenesulfanilide, N-methylbenzenesulfonamide, N-n-octylbenzenesulfonamide, N-butyl-p-toluenesulfonamide, N-n-butyl-p-toluenesulfonamide,
-nr'silbenzenesulfonamide and the like.

Examples of aromatic sulfonimides include D-sulfobenzimide and 1,2-cyclohexane sulfocarboximide.

The heating time indicator of the present invention has a resin layer between the layer containing the electron-donating color-forming organic compound and the layer containing the electron-accepting organic compound, and the resin used for this resin layer is For example, polyvinyl chloride, vinyl chloride, vinyl acetate copolymers, phenoxy resins, acrylic resins, polyurethane resins, polyamide resins, polyester resins, aromatic polyester resins, celluloses such as ethyl cellulose and cellulose acetate, polyvinyl formal resins,
Various resins such as polyvinyl butyral resin, polycarbonate resin, polyvinylidene fluoride resin, polystyrene resin, and polyvinyl alcohol resin can be used alone or in combination of two or more.

In order to produce the heating time indicator of the present invention, for example, the electron-donating color-forming organic compound is dissolved on a suitable support such as a film, a plastic sheet, or paper, together with a suitable binder resin as necessary. Alternatively, a color forming agent layer is provided by dispersing and coating or printing. On the other hand, similarly, the electron-accepting organic compound is dissolved or dispersed and coated or printed on the support, if necessary, together with a suitable binding resin to provide a color developer layer.

Next, a thin resin film is created using a method such as casting using the above-mentioned resin, and this thin resin film is sandwiched between a color forming agent layer and a color developing agent layer and brought into close contact with each other to obtain a heating time indicator. It will be done.

Another manufacturing method is to coat or print a color forming agent layer containing an electron-donating color-forming organic compound or a color developer layer containing an electron-accepting organic compound on the resin thin film, and then A color developer layer or a color forming agent formed on a support is brought into close contact with the support.

Yet another method is to provide a color developer layer on a suitable support.
There is a method of coating and laminating a resin layer and a color former layer in this order, or a color former layer, a resin layer, and a color developer layer in this order.

As the binding resin used as necessary for the color forming agent layer containing an electron-donating color-forming dye and the color developer layer containing an electron-accepting organic compound, the same resin as that used for the resin layer may be used. Can be done.

When the heating time indicator of the present invention is heated to a certain temperature,
As a predetermined time elapses, rapid color development occurs to indicate the time. When heated to a certain temperature, the electron-accepting organic compound in the color developer layer melts, moves through the resin layer, contacts the electron-donating color forming dye in the color former layer, and develops color. Therefore, time control is mainly performed by the resin layer between the color former layer and the color developer layer.

The time it takes for color to develop varies depending on the type of resin, and for the same resin, the thicker the resin, the longer it takes. Furthermore, the melting point of the electron-accepting organic compound of the color developer layer used needs to be lower than the heating temperature. Therefore, the time until color development, that is, the time to display, can be set in the range from several seconds to several hours by appropriately selecting the type and thickness of the resin in the resin layer, and the heating temperature at which the time should be displayed. By selecting the type of electron-accepting organic compound, it is possible to cope with the temperature in the range of 30 to 200°C. Furthermore, various hues can be obtained by selecting the type of electron-donating color-forming organic compound.

By attaching the heating time indicator of the present invention obtained as described above to an object to be heated, it is possible to clearly indicate that the object has been kept at a constant temperature for a predetermined period of time by rapid color development. can. Therefore, it is effective for displaying, for example, the heating time of instant foods, dry foods, etc., and the time for rehydrating in hot water.

Example 1 6 parts by weight of crystal violet lactone, vinyl chloride-vinyl acetate copolymer (Denka Vinyl #100OA, manufactured by th Kagaku Co., Ltd.), as an electron-donating color-forming organic compound, were placed on a polyester film having a thickness of 75 μm. A solution consisting of 6 parts by weight and 68 parts by weight of tetrahydrofuran was applied and dried at 100° C. for 5 minutes to provide a color former layer with a thickness of about 10 μm.

Next, a small amount of iron stearate powder was rubbed on a smooth glass plate made hydrophobic by wiping it thoroughly with clean absorbent cotton. was applied with a doctor blade to form a resin layer with a thickness of 6.2 μm.

On this resin layer, as an electron-accepting organic compound, a mixture consisting of 10 parts by weight of n-butyl p-hydroxybenzoate, 10 parts by weight of 1 Ovt% polyvinyl alcohol aqueous solution (Kuraray Boval 117: manufactured by Kuraray), and 80 parts by weight of water was applied. The dispersion was dispersed using a ball mill for 2 days, then applied with a doctor blade, dried at 40°C, and made into a layer with a thickness of about 10 μl.
A color developer layer was provided.

Next, the resin layer and color developer layer provided on the glass plate were gently peeled off from the glass plate, and this was pressed onto the color developer layer so that the resin layer surface was in close contact with the glass plate to obtain a heating time indicator of the present invention.

The heating time indicator obtained in this way was placed in a constant temperature bath at a temperature of 80°C and the state of color development was examined.
The color started to turn blue in seconds, and after 3 minutes and 10 seconds, it became a clear blue color, and it was possible to display the time at 80° C. for about 3 minutes.

(Figure 2 shows the relationship between the elapse of time and the color density.) When this heating time indicator was attached to the top of the lid of instant cup noodles and hot water was poured, the color rapidly developed in about 3 minutes. It turned a clear blue color.

Examples 2 to 9 In Example 1, the electron-donating color-forming organic compound of the color former layer, the resin and film thickness of the resin layer, and the electron acceptability of the color developer layer were as shown in Table 1. Except for this, a heating time indicator of the present invention was produced in the same manner as in Example 1. This was placed in a constant temperature bath at a predetermined temperature in the same manner as in Example 1, and the time to start color development and the time until color development became clear were measured, and the results are shown in Table 1.

The electron-donating coloring dyes used in the examples are shown below.

(a) Crystal violet lactone (b) 3-diethylamino-? -N-benzy-N-cyclohexylaminofluorane (c) 1,3-dimethyl-6-dinithylaminofluorane (-1 [Effect] As explained above, the heating time indicator of the present invention As time elapses, a clear hue change occurs rapidly, making it clear that time has elapsed.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are enlarged sectional views of the heating time indicator of the present invention, and FIG. 2 is a graph showing changes in color density with respect to heating time of the heating time indicator of Example 1. DESCRIPTION OF SYMBOLS 1...Support, 2...Developer layer containing an electron-accepting organic compound, 3...
- Resin, 4... Coloring agent layer containing an electron-donating color-forming organic compound.

Claims (1)

[Claims] A heating time indicator comprising a layer containing an electron-donating color-forming organic compound and a layer containing an electron-accepting organic compound, and a resin layer provided between these two layers.