JPH0679839B2 - Storage temperature management label - Google Patents

Description

TECHNICAL FIELD The present invention relates to a storage temperature management label.

More specifically, it irreversibly develops color when exposed to a predetermined temperature or higher, and is applied to various types of articles that require temperature control, such as frozen foods, fresh flowers, pharmaceuticals, etc., during transportation or storage,
The present invention relates to a temperature control label effective for detecting whether or not a substance is kept at a control temperature.

(Prior Art) Conventionally, there are a wide variety of articles that need to be displayed, stored, transported, and the like under strict temperature control. Especially,
With the widespread use of cold chains in recent years, a large amount of frozen or chilled food has been circulating, and the handling thereof requires strict temperature control. That is, in the case of such frozen or chilled foods, if they are not controlled below the temperature specified for each food in the process of transportation and storage until they are handed to general households after they are manufactured, the contents may be altered and bacteria may propagate. Corruption may occur and become a major social problem.

Such strict temperature control is not limited to frozen or refrigerated foods, but also fresh flowers, pharmaceuticals (eg, anti-cancer drugs for certain hands, vaccines, blood for transfusion), photographic chemicals, chemicals, foods, magnetic materials, etc. There are many kinds of things.

However, under the present circumstances, it is difficult to easily know whether or not an article that requires strict temperature control represented by frozen and chilled foods is manufactured, and whether the necessary temperature control is strictly adhered to the user. Appropriate temperature control labels are required in related industries.

(Problems to be Solved by the Invention) An object of the present invention is to provide a temperature management label capable of easily detecting a storage temperature history in order to meet such a demand.

(Means for Solving Problems) The inventors of the present invention have earnestly studied to solve the above problems, and arrived at the present invention. That is, the present invention provides a support on which (A) a layer containing a developer which is a benzoquinone derivative substituted with an electron-withdrawing group, (B) a layer containing a polymer substance as an essential component, and (C) optional. A layer containing a non-volatile hydrophobic microcapsule having a melting point of and a methine compound,
If necessary, (D) a protective layer for imparting water resistance and / or solvent resistance is sequentially laminated, and an adhesive layer and a release paper layer are provided on the back side of the support. Is a label for storage temperature control that can be easily attached to an article requiring strict temperature control, develops color when the temperature exceeds a predetermined temperature, and can easily detect the temperature history with the naked eye.

The storage temperature control label of the present invention basically has the above-mentioned configuration, and the details of the configuration are as follows.

As the support, various film webs, specifically, paper, impregnated paper, synthetic paper (various synthetic resin-based paper-like films), various plastic films, and the like are used.

Since the label for storage temperature control is often used in an environment with high water content such as refrigerated or frozen food, the support is preferably synthetic paper having various water resistance, various plastic films or resin-impregnated paper.

The thickness of the support is generally 30 to 200 µ.

The essential component of the first layer containing the developer, which is overlaid on the support, is a colored dye obtained by oxidizing the methine dye precursor by molecular contact with the methine dye precursor described later. A color developing agent having the ability to form a compound is used, and a color developing agent having a general formula (I) or (II) is preferable. (In the formula, R _{1 to} R ₈ are a halogen atom, a cyano group, a nitro group,
Electron withdrawing selected from carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, aralkyloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, aralkylsulfonyl group, alkoxysulfonyl group, aryloxysulfonyl group, aralkyloxysulfonyl group and acyl group. A hydrogen atom, an alkyl group, an alkoxy group, an aralkyloxy group, an alkylthio group, or an arylthio group, and the adjacent carboxyl group may form an imide ring) A non-volatile benzoquinone derivative substituted with an electron-withdrawing group can be mentioned. Particularly preferred among these are benzoquinone derivatives that are non-volatile p-benzoquinone derivatives substituted with two or more electron-withdrawing groups.

Specific examples of the benzoquinone derivative used in the present invention include 2,3-dicyano-5,6-dichloro-1,4-benzoquinone and 3,4-dibromo-5,6-dicyano-1,4- Benzoquinone, 2,3,5,6-tetrabromo-1,4-benzoquinone,
2,3,5,6-tetraiodo-1,4-benzoquinone, 2,3,5,6
-Tetraethoxycarbonyl-1,4-benzoquinone, 2,
3,5,6-tetra-i-butoxycarbonyl-1,4-benzoquinone, 3,4,5,6-tetra-propyloxycarbonyl-1,4-benzoquinone, 2,5-getoxycarbonyl-1,
4-benzoquinone, 2,5-di-n-hexyloxycarbonyl-1,4-benzoquinone, 2,5-di-cyclohexyloxycarbonyl-1,4-benzoquinone, 2,5-dibenzoyl-1,4-benzoquinone, 2,5-di-n-butoxycarbonyl-3,6-dichloro-1,4-benzoquinone, 2,5-di-
Ethoxycarbonyl-3,6-dibromo-1,4-benzoquinone, 2,5-di-n-octoxycarbonyl-3,6-dibromo-1,4-benzoquinone, 2,5-di-benzyloxycarbonyl-3 , 6-dichloro-1,4-benzoquinone, 2,5-dibenzoyl-3,6-dichloro-1,4-benzoquinone, 2,5
-Diacetyl-3,6-dibromo-2,4-benzoquinone, 2,
5-diethoxycarbonyl-3,6-diphenylsulfonyl-1,4-benzoquinone, 2,5-di-i-butoxycarbonyl-3,6-di-4'-tolylsulfonyl-1,4-benzoquinone, 2, 5-di-cyclohexyloxycarbonyl-3,6
-Di-4'-tolylsulfonyl-1,4-benzoquinone,
2,5-di-n-octyloxycarbonyl-3,6-di-
4'-cyclohexylphenylsulfonyl-1,4-benzoquinone, 2,5-di-n-hexyloxycarbonyl-
3,6-di- (3 ', 4'-dimethylphenylsulfonyl)
-1,4-benzoquinone, 3,4,5,6-tetraethylsulfonyl-1,4-bezoquinone, 2,3,5,6-tetra-n-octylsulfonyl-1,4-benzoquinone, 2,5-di -Cyclohexyloxycarbonyl-3-benzylsulfonyl-1,4
-Benzoquinone, 2,5-di-n-butoxycarbonyl-
3- (p-tolyl) -sulfonyl-1,4-benzoquinone, 2,5-diethoxycarbonyl-3- (2 ', 5'-dimethylphenylsulfonyl) -1,4-benzoquinone, 2,5
-Di-n-butoxycarbonyl-3,6-di-n-butoxysulfonyl-1,4-benzoquinone, 2,5-di-4'-toluylsulfonyl-3,6-dibromo-1,4-benzoquinone, 2 -Benzoyl-1,4-benzoquinone, 2-phenylsulfonyl-1,4-benzoquinone, 2- (4'-methylphenyl) sulfonyl-1,4-benzoquinone, 2-
Examples thereof include benzoquinone derivatives such as (4'-diphenylylsulfonyl) -1,4-benzoquinone and 2-benzylsulfonyl-1,4-benzoquinone, but the present invention is not limited thereto.

These benzoquinone derivatives are wet-milled in the presence of a surfactant or a protective colloidal substance to give an aqueous suspension, which is used for preparing a coating liquid.

The layer containing the developer in the label of the present invention is formed by a method of coating or printing a coating liquid containing the developer on a support.

The coating method is generally a coating liquid prepared by mixing a fine particle dispersion obtained by pulverizing the above benzoquinone derivative, preferably in the presence of a surfactant, with various other materials such as inorganic pigments and adhesives. Is coated on a support by various coating methods such as air knife coating, bar coating, blade coating, and kiss coating, and dried. The coating amount is generally 2 g / m ^{2 to} 20 g / m ^2, but it varies depending on the composition of the coating liquid used and the like.

Next, the second layer (B), which contains the polymeric substance as an essential component, is laminated on the upper layer of the layer containing the color-developing agent to form the third layer.
The non-volatile hydrophobic compound in which the methine dye precursor derived from the layer is dissolved is brought into contact with the benzoquinone derivative which is the developer of the first layer to form an irreversible color development image by the methine dye precursor and the benzoquinone derivative. A layer used to control the time required until (hereinafter referred to as a spacer layer)
Is. Specifically, the above-mentioned non-volatile hydrophobic compound is provided on the first layer containing the above-mentioned color developer by coating or the like with various kinds of natural or synthetic polymer substances having an appropriate barrier property.

As the polymer substance, specifically, polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose,
Natural, semi-synthetic or synthetic water-soluble polymers such as gelatin, casein, starch derivative, synthetic rubber latex such as styrene / butadiene rubber latex, methyl methacrylate / butadiene rubber latex, chloroprene rubber latex, and modified latex, etc. , Various unsaturated monomers alone, or a synthetic resin dispersion obtained by emulsion polymerization in the coexistence of two or more kinds, for example, dispersions of homopolymers and copolymers of various acrylic monomers (for example, Styrene butyl acrylate copolymer emulsion, acrylonitrile-ethyl acrylate-butyl acrylate copolymer emulsion, styrene-ethyl acrylate copolymer, etc.) are water-soluble or water-dispersible polymer substances. These polymer substances are entirely or partially coated on the upper layer of the developer layer containing the benzoquinone derivative. As a coating method, a commonly used means such as air knife coating, Mayer bar coating, blade coating and the like is used. The coating amount is appropriately determined according to the polymer substance used and the required color development time characteristics. Generally, 0.5 to 10 g / m ^{2 is} coated. Alternatively, the second layer may be formed by a printing method or a hot melt coating method.

Then, the third layer overlaid on the second spacer layer is (i) a layer containing microcapsules of a non-volatile hydrophobic substance having an arbitrary melting point and a methine dye precursor, or (ii) It is a layer containing microcapsules containing both the above hydrophobic substance and the methine dye precursor.

The third layer can be formed by two methods, which are usually a partial printing method and a coating method. Although these methods are appropriately used according to the design of the label, the printing method is generally used for the label.

As a printing method of a coating liquid containing microcapsules,
Generally, various known printing methods such as a screen printing method, a flexographic printing method, and a gravure printing method are used, but the microcapsules are pressure rupturable, and further, a general dry coating amount is 5 to 10 g. Since the coating amount is limited in / m ² and other printing methods, the screen printing method can be mentioned as a preferable method. The ink used in the printing method is generally a dispersion liquid of the above-mentioned non-volatile hydrophobic substance microcapsules and fine particles of a methine dye precursor, or a microbe of a hydrophobic substance in which a methine dye precursor is dissolved. A capsule is mixed with a water-dispersed or water-soluble adhesive and, if necessary, various thickeners, dispersants, stabilizers, defoamers, water-proofing agents, pigments, etc. Used as a printing ink suitable for the method.

A non-volatile hydrophobic substance having an arbitrary melting point (hereinafter, simply referred to as a hydrophobic substance) is a substance which can be converted into a solid-liquid interconduit inside the microcapsule depending on the ambient temperature and is released from the microcapsule. Thus, it is a non-volatile compound that behaves as a solid below a predetermined temperature and as a liquid above a predetermined temperature. Specific compounds include tricaproin glyceride, nonylbenzene, diethyl pimelate, n-butyl benzoate, n-decylcyclopentane, 1-pentylnaphthalene, octyl enanthate, and heptyl caprate in order from the compound having the lowest melting point. , 1-
n-butylnaphthalene, azelaic acid-diethyl, methyl caproate, 1-hexylnaphthalene, dodecyl acetate, linoleyl alcohol, octyl caprylate, decyl acetate, ethyl undecanoate, decylbenzene, 1,6-
Dimethylnaphthalene, 1-ethylnaphthalene, 1-linoleo-2,3-dicaprylin-glyceride, acetic acid-undecyl, 1-lauro-2,3-dilinolein triglyceride, 1-caproyl-2,3-distearin triglyceride, undecyl caproate , Caprylic acid-heptyl, n
-Nonylcyclohexane, 1-propylnaphthalene, n
-Undecylcyclopentane, 1-myristo-2,3-dilinolein triglyceride, 1-heptylnaphthalene,
2-ethylnaphthalene, 1-caprylyl-2,3-diolein-triglyceride, diethyl sperate, undecylbenzene, n-dodecyl-cyclopentane, ethyl tridecanoate, butyl laurate, dodecyl caproate,
Methyl ricinoleate, 2-n-pentylnaphthalene, 1,
3-dimethylnaphthalene, azelaic acid-dimethyl, dimethyl sperate, 2-n-hexylnaphthalene, heptyl laurate, 1-n-octylnaphthalene, ethyl laurate, n-decylcyclohexane, diethyl sebacate, 1-linoleo-2. , 3-dicaprin-triglyceride, butyl myristate, 2-n-heptylnaphthalene, tetradecyl caproate, n-dodecylbenzene,
1-oleo-2,3-dicaprin-triglyceride, 2-
Oleo-1,3-dicaprine-triglyceride, methyl laurate, n-tridecylcyclopentane, n-undecylcyclohexane, tridecyl caproate, nonylnaphthalene, n-tetradecylcyclopentane, n-pentadecane, tridecylbenzene, 1 -Heptadecene, 2
-N-octylnaphthalene, 2-n-nonylnaphthalene, 2-undecanone, ethyl myristate, n-dodecylcyclohexane, 1-myristo-2,3-diolein-triglyceride, isobutyl palmitate, ethyl pentadecanoate, decylnaphthalene, n -Tetradecylbenzene, caproic acid-pentadecyl, n-pentadecyl-cyclopentane, 1-octadecene, hexadecane,
1-palmito-2,3-diolein-triglyceride, butyl palmitate, methyl myristate, methyl pentadecanoate, amyl palmitate, methyl oleate, 2
-N-decylnaphthalene, propyl palmitate, n
-Hexadecylcyclopentane, octadecane, apiol, benzylidenemalonic acid-diethyl, nonadecane,
Benzyl cinnamate, diethyl terephthalate, 1-tetradecanol, 1,2-diphenylethane, 1,3,5-trimethoxybenzene, p-dimethoxybenzene, octadecanol, 9-ethylanthracene, p-methyl Examples thereof include hydrophobic non-volatile organic compounds having a sharp melting point of −30 ° C. to 70 ° C. and a boiling point of 200 ° C. or higher, such as benzophenone, but are not limited to the exemplified compounds.

Further, the thimene dye precursor is represented by the general formula (I) (In the formula, X, Y and Z are phenyl group which may have a substituent, naphthyl group which may have a substituent, β-styryl group which may have a substituent or aromatic which may have a substituent. And a heterocyclic ring residue, which may be the same or different, and two of X, Y, and Z may be bonded to each other to form a ring. In the case where there is one or more aromatic heterocyclic ring residues among them, at least one amino group, a substituted amino group or a substituted amino group in the phenyl group, naphthyl group or β-styryl group in the para position to the central methine group of the molecule, or Having a lower alkynyl group), and specifically includes (A-1) a triaminotriphenylmethane dye such as 4,4 ′, 4 ″ -tris-dimethylamino. -Triphenylmethane, 4,4'4 " -Tris-diethylaminotriphenylmethane, 4,4'-bis-methylamino-4 "-dimethylamino-triphenylmethane, 4,4'-bis-
(N-methyl-N-benzylamino) -4 ″ -dimethylamino-triphenylmethane, 4,4′-bis-dimethylamino-4 ″ -N-methyl-N-benzylamino-triphenylmethane, 4,4 ′, 4 ″ -Trisamino-3-methyl-triphenylmethane, 4,4′-bis-methylamino-4 ″ -dimethylamino-3,3′-dimethyl-triphenylmethane, bis (3-methyl-4) -Benzylamino)
-4'-Dimethylamino-triphenylmethane, etc. (A-2) Diamino-triphenylmethane-based dye, for example, 4,4'-bis-dimethylamino-triphenylmethane, 4,4'-bis-dimethylamino- 4 ″ -methyl-triphenylmethane, 4,4′-bis- (N-benzyl-N
-Ethylamino) -triphenylmethane, 4,4'-bis-dimethylamino-4 "-methoxytriphenylmethane, 4,4'-bis-dimethylamino-4" -ethoxytriphenylmethane, 4,4'- Bis-dimethylamino-
4 "-ethoxy-3'-methyl-triphenylmethane,
4,4'-bis-dimethylamino-3 ', 4'-dimethoxytriphenylmethane, 4,4'-bis- (N-benzyl-
N-methylamino) -4 ″ -methoxy-triphenylmethane and the like, (A-3) monoaminotriphenylmethane-based dye, for example, 4,4′-dimethoxy-4 ″ -dimethylamino-triphenylmethane, 4, 4'-dimethoxy-3 "-methyl-
4 ″ -methylamino-triphenylmethane, 4-methoxy-4 ″ -diethylamino-triphenylmethane, etc. (B) Naphthylmethane dye such as bis- (4-dimethylamino-naphthyl-1) -4′-dimethyl Aminophenylmethane, (C) β-styrylmethane dye, for example, bis (4-
Dimethylaminophenyl) -β-styrylmethane, bis (4-dimethylaminophenyl) -β- (4′-dimethylaminostyryl) -methane, bis (4-dimethylaminophenyl) -β- (4′-methoxystyryl) Methane, bis (3-methyl-4 [N-phenyl-N-methyl-amino] phenyl-β-styrylmethane, bis (3-
Methyl-4-methylamino-phenyl) -β- (4'-
(Methoxystyryl) -methane and the like, (D) indolylmethane-based dye, for example, bis (1-ethyl-2-methyl-indol-3-yl)-(4′-
Ethoxyphenyl) -methane, bis (1-ethyl-2-)
Methyl-indol-3-yl)-(4'-dimethylaminophenyl) -methane, 4-dimethylaminophenyl- (1'-ethyl-2'-ethyl-indole-3'-
Illy) -phenylfutane, bis (1-butyl-2-methyl-indol-3-yl) -4′-methoxyphenyl-methane, etc. are exemplified, but not limited thereto.

The methine dye precursor represented by the general formula (I) is
(1) In the presence of a dispersant or a polymer having a protective colloid ability in a solvent (preferably water) which does not dissolve them,
It is used as a suspension of microparticles by mixing well or by wet pulverization and mixed with hydrophobic substance microcapsules, or (2) after being dissolved in a hydrophobic substance,
It is used in the label of the present invention by any method of being used after being microencapsulated. Among these methine dye precursors, those having a tendency to gradually undergo air oxidation coloring upon storage or exposure to light are (1) water-soluble alkanolamines, in order to increase the storage stability of the compound,
An appropriate amount of one or more selected from (2) a water-soluble sequestering agent and (3) a quaternary ammonium salt is added to a coating or printing composition containing a suspension or microcapsules.

Examples of the water-soluble alkanolamines (1) include alkanolamines having a tertiary amino group and tris-
N- (2-hydroxyethyl) amine, Tris-N-
(2-Hydroxypropyl) -amine, Tris-N-
Specific examples include (3-hydroxylpropyl) amine and N, N-dipropyl-N- (2-hydroxyethyl) amine.

Examples of the sequestering agent (2) include ethylenediamine-tetraacetic acid, N-hydroxyethyl-ethylenediamine, N, N ', N'-triacetic acid, diethylenetriamine-pentaacetic acid, N-hydroxyethyl-imino-diacetic acid, ethylenediamine. Specific examples thereof include -N, N'-diacetic acid, 1,3-diaminopropan-2-oltetraacetic acid, nitrilotriacetic acid and their alkali metal salts.
Further, specific examples of the quaternary ammonium salt of (3) include lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, trimethyl benzyl ammonium chloride and the like.

When (1) an alkanolamine, (2) a sequestering agent, and (3) a quaternary ammonium salt are used, the total amount thereof is 1 to 100 relative to 100 parts by weight of the methine dye.
The amount is 00 parts by weight, preferably 1-1000 parts by weight.

The non-volatile hydrophobic substance having an arbitrary melting point or the non-volatile hydrophobic substance in which the methine dye precursor is dissolved can be prepared by various known methods, for example, (1) coacervation method using gelatin, (2) interface Polymerization method or (3) In-Sit
Microcapsules are prepared by the polymerization method. Among them, the microcapsules using the aminoaldehyde resin as a membrane material by the In-Situ polymerization method have (a) a dense wall membrane with low permeability, (b) a high solid content concentration, ( c) It is preferable in that it does not rot.

Although the label for storage temperature control of the present invention has the above-mentioned constitution, the label for color development of the third layer may further have resistance to the environment in which the coloring function of the label is used (specifically, water resistance, When it is necessary to have oil and fat resistance), a protective layer is further overlaid. Polymeric substances and / or wax-like substances are most preferable for use in such a protective layer, and they provide a film having water resistance and / or solvent resistance.

Specifically, an aqueous dispersion of these polymer substances and / or wax-like substances is used to (1) coat the microcapsule layer by a coating spray method or a printing method, or (2) hot melt coating or spray. Examples of the method include a method of coating the upper layer of the label with a thermoplastic hot melt cold set type material by a method, and (3) a method of laminating a resin film having an adhesive layer on the upper layer of the microcapsule layer. These protective layers are appropriately selected in consideration of the conditions under which the label is used.

The thus-obtained label for storage temperature control of the present invention is generally provided with a pressure-sensitive adhesive layer on the back side of the support, and can be easily attached by a labeler to an article requiring temperature control. used.

Such a label for storage temperature control of the present invention has the above-mentioned configuration, and when the microcapsule layer is provided by a printing method, it can be a label having an arbitrary pattern. Further, by using two or more kinds of microcapsules of hydrophobic substances having different melting points and combining a plurality of methine dye precursors, a label that develops color at two or more different temperatures, and different hues at two or more different temperatures. It is also possible to obtain a label that develops color.

(Operation and effect) The label for storage temperature control of the present invention is (2) a wire in which the label surface is passed between (1) rolls before being used by being attached to an article requiring temperature control. The microcapsules are destroyed and initialized by processing with an engraving method such as a dot printer method or an impact type engraving device.

The initialization temperature is preferably lower than the color development start temperature of the label, that is, the hydrophobic substance in the microcapsules is preferably in a solid state. However, it may be stored below the color development start temperature after being initialized above the color development start temperature due to the presence of the spacer material.

In this state, no change occurs on the label, but when exposed above the color development temperature of the label, the hydrophobic compound inside the capsule melts and becomes an oil that diffuses through the voids in the broken microcapsule wall, and the spacer is removed. By passing through and reaching the developer layer, a color image is gradually produced.

The storage temperature control label of the present invention has a very small area and a simple structure, and (1) the solid-liquid conversion temperature can be selected by selecting a non-volatile hydrophobic substance in the microcapsules.
That is, it is possible to arbitrarily select the color development start temperature, (2) to easily control the time required for color development by selecting the substance used for the spacer layer, and (3) to select any dye precursor to be used. Being able to select various colors,
(4) It is possible to create a label that changes in two or more steps of temperature. (5) Reliability is improved because the color development is based on an irreversible and quantitative oxidation reaction between a methine dye precursor and a benzoquinone derivative. It has extremely excellent characteristics such as obtaining a colored image having Furthermore, the temperature control function is easily activated by the capsule destruction by pressure.By incorporating the microcapsule destruction mechanism by pressure into the existing labeler, it is necessary to strictly control the temperature of individual target substances such as frozen foods, refrigerated foods, and pharmaceuticals. It can be efficiently attached to a substance to be controlled and individual temperature control can be easily performed.

(Examples) Hereinafter, the present invention will be specifically described with reference to Examples.

In the text, all parts are parts by weight.

Example 1 An aqueous coating solution (30%) having the following composition on a polypropylene-based synthetic paper (Nisshinbo Peachcoat Wφ-110)
(Used as an aqueous dispersion) Was coated and dried with a Meyer bar coater to a dry coating amount of 7 g / m ² to obtain a developer layer coated sheet.

On top of that, an acrylic emulsion (solid content) containing acrylonitrile and butyl acrylate as main components is used.
45%) to 10% and dried with a Meyer bar coater to a coating amount of 2.0 g / m ² and dried to provide a spacer layer consisting of a polymer film layer on the developer layer. .

Then, an acrylic emulsion pressure-sensitive adhesive was applied to a silicone-treated release paper of 80 g / m ² to a thickness of 20 μ and dried, and the back surface of the above-mentioned coating layer was laminated (laminated) to obtain a printing original fabric. .

Next, a water-based ink with the following composition (solid content 40%, viscosity
10000cps), Pattern printing was performed on the spacer surface of the printing original fabric using a screen printing plate having 225 mesh polyester fiber. The dry coating amount of the pattern printed part was 10 g / m ² .

Die-cut the above screen-printed sheet into a label,
Slitting was performed to obtain a storage temperature control label (A).

The label of this example is activated by destroying the microcapsules, and then exposed to a temperature of 12 ° C or higher, the myristic acid methyl ester in the microcapsules becomes solid to liquid,
It penetrates the spacer layer slowly and develops a green color. 12 ° C
No color develops if stored below.

The label of this example is useful as an indicator of the storage temperature history of refrigerated food.

Example 2 A synthetic paper based on polyethylene terephthalate (Nisshinbo Peachcoat WE-110) and an aqueous coating solution having the following composition (used as a 35% aqueous dispersion) Was coated and dried using an air knife coater so that the dry coating amount was 6 g / m ² to obtain a developer coated sheet.

Acrylonitrile-styrene-ethyl acrylate as the main component acrylic emulsion (solid content 45%) 20
%, And coat and dry the developer coating sheet with an air knife coater to a dry coating amount of 2.8 g / m ^2, and provide a spacer layer made of a polymer substance on the developer layer. It was

Then, a release paper treated with 70 g / m ² of silicon was coated with an acrylic emulsion pressure-sensitive adhesive at a thickness of 15 μm and the pressure-sensitive adhesive surface and the back surface of the above-mentioned coating layer were laminated (laminated) to obtain a printing original fabric.

Next, a water-based ink with the following composition (solid content 45% viscosity
8000 φS) was prepared and solid part by weight Microcapsules of myristic acid ethyl ester in which dye precursor was dissolved * 1 100 MSBR latex 15 Alginic acid Na salt 2 Trimethylbenzylammonium chloride 2 * 1) 4,4'- as dye precursor Bis (N-benzyl-N-methylamino) -4 "-dimethylaminotriphenylmethane dissolved in 2% by weight of myristic acid ethyl ester microencapsulated with a melamine resin film by an in-situ polymerization method.

Pattern printing was performed using a screen plate in the same manner as in Example 1. The dry coating amount of the pattern printed portion was 12 g / m ² .

Further, a polyvinylidene chloride-based latex was spray-coated on the entire surface so as to be dry-coated (dry coating amount was 1.0 g / m ² ) to provide a protective layer.

In this way, two types of screen printing were performed, and the sheet provided with the protective layer was die-cut to obtain a label (B) for storage temperature control.

The label of this example is gradually and irreversibly discolored at a temperature of 7 ° C. or higher by performing a microcapsule breaking operation.

Pass the label of this example through an auto labeler (automatic labeling machine) equipped with an engraving machine that destroys the capsule with roll pressure, and remove the microcapsules on the label with a linear pressure of 50 kg / cm at 15 ° C. To destroy. After sticking to the refrigerated food with a labeler, after 5 minutes, store the food in a refrigerating room controlled at + 0 ° C. Stored at 0 ° C for 24 hours. At this point in time, the pattern-printed part does not blink and develops color. When the labeled food was moved to a room at a temperature of 10 ° C., color development started 15 minutes later, and became dark blue after 6 hours.

Similarly, the food with the label of this example attached at 0 ° C.
After storing it for a while and moving it to a room with a temperature of 15 ° C,
Color development started after 10 minutes and became dark blue after 3 hours.

Example 3 Using the printing stock of Example 2, an aqueous ink (solid content 35%, viscosity 7000 cps) having the following composition was prepared in its spacer layer. Was used to perform pattern printing using a screen printing plate. The dry coating amount of the pattern printed part was 18 g / m ² .

Paraffin wax as a main component in the upper layer of the sheet,
A hot melt composition (softening point 70 ° C.) was hot melt coated to a thickness of 5 μm to form a protective layer. The sheet was subjected to slitting die-cutting into a label shape to obtain a storage temperature control label (C).

The label of this example destroys the microcapsules, and after being activated, when exposed to a temperature of -15 ° C or higher, the pattern-printed portion gradually develops a red color.

The label of this example is useful for controlling the storage temperature of frozen foods and the like.

Example 4 (A), (B) Two types of aqueous inks were prepared (both
40%, viscosity 7500cps) (A) Solid part by weight Methylnonylketone microcapsules 100 Methine dye precursor * 1) 3 MBR latex 15 Trimethylbenzylammonium chloride 2 Hydroxyethylcellulose 3 * 1) 4,4 ', 4 " -Tris-dimethylaminophenylmethane (B) Solid weight part-n-butyl palmitate microcapsules 100 Methine dye precursor *) 3 MBR latex 15 Trimethylbenzylammonium chloride 2 Hydroxyethylcellulose 3 * 2) 4,4 ' -Bis- (dimethylamino) -3 "-methyl-4" -ethoxytriphenylmethane Screens of the water-based inks (A) and (B) were respectively placed adjacent to the spacer surface of the printing material obtained in Example 2. Pattern printing was performed using the plate, and the coating amount of the screen printing part was 10 g / m ² each. It was

Die-cutting slitting was carried out in the same manner as in Examples 1 to 3 to obtain a label (D) for storage temperature control.

The microcapsules were destroyed by passing the label of this example between metal rolls at 0 ° C., and the temperature dependence of color development was investigated. When the temperature is raised to 5 ° C., the part printed with the water-based ink (A) develops blue color in one hour, but the part printed with the water-based ink (B) does not change.

When the temperature is further raised to 12 ° C, the portion printed with the water-based ink (B) changes to green in 6 hours.

That is, the label of this example is a useful label that can manage two different storage temperature histories by providing two types of printing layers having different coloring start temperatures on the same label surface.

Claims (2)

[Claims] 1. In a label for storage temperature control, which irreversibly develops a color, a layer containing (A) a color developer on a support,
(B) a layer containing a polymer substance as an essential component, (C)
A label for storage temperature control, which comprises a non-volatile hydrophobic substance microcapsule having an arbitrary melting point, a layer containing a methine dye, and (D) a protective layer, which are sequentially laminated, if necessary. 2. A label containing a color developer (A) on a support in a label for storage temperature control which develops color irreversibly.
(B) a layer containing a polymer substance as an essential component, (C)
A layer containing microcapsules encapsulating a non-volatile hydrophobic substance having an arbitrary melting point and a methine dye precursor,
A label for storage temperature control, further comprising (D) a protective layer sequentially laminated as required.