JPH0834168A - Thermally color-changeable light blocking-light pervious microcapsule pigment - Google Patents

Abstract

PURPOSE:To provide the title pigment showing hysteresis characteristics by a temp. change to discolor, having the interchangeability of a white opaque state and a colorless transparent state, applied variously in the combination with a conventional thermally color-changeable material and variously changed in hysteresis width. CONSTITUTION:A curve obtained by plotting a change of transparency due to a temp. change changes accompanied by hysteresis width [DELTAH(TF-TE)]. The interchangeability between a white opaque state and a colorless transparent state is shown and the white opaque state changes when reaches temp. TCU in a temp. rising process in the white opaque state and perfectly becomes the colorless transparent state within a temp. region of TD or higher. In a temp. falling process in this colorless transparent state begins to change when reaches temp. TS lower than temp. TC and perfectly becomes the white opaque state within a temp. region of TA or lower. A hysteresis characteristic enabling the coexistence of the white opaque state and the colorless transparent state within the temp. region between temp. TB and temp. TC is imparted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermochromic light-shielding-light-transmitting microcapsule pigment. More specifically, the present invention relates to a thermochromic light-shielding / light-transmitting microcapsule pigment that exhibits a hysteresis characteristic due to temperature change and changes color, and has alternation in both a white opaque state and a colorless transparent state.

[0002]

2. Description of the Related Art Conventionally, some reversible thermochromic materials exhibiting a color-colorless reversible color change or a color [1] -color [2] reversible color change due to temperature change have been disclosed by the present applicants. Has been disclosed (Japanese Patent Publication No. 51-447).
No. 06, Japanese Patent Publication No. 51-44708, Japanese Patent Publication No. 1
No. 29398, etc.). The thermochromic material discolors at a discoloration temperature as a boundary, and only one specific state exists in the normal temperature region of both states before and after the change. That is, the other state returns to the state exhibited in the normal temperature range when the application of heat or cold heat required for the development of the state disappears. It is a reversible thermochromic material of a type that exhibits a small hysteresis width (ΔH) with respect to a temperature-color density curve due to so-called temperature change and changes color (see FIG. 5). As the other thermochromic material, it exhibits a large hysteresis width (ΔH) due to temperature change, and when the temperature is increased from the low temperature side of the discoloration temperature range, it is decreased from the high temperature side of the discoloration temperature range. In the case where the color changes along a path that is significantly different from that in the case, and even after removing the application of heat or cold heat required for the color change, the low temperature side color point or less in the normal temperature range between the low temperature side color change point and the high temperature side color change point. Alternatively, a color memory thermochromic type of a type having so-called tautomerism between a colored state and a colorless state or tautomerism between a colored [1] and a colored [2], which retains a state of being discolored at a high temperature side discoloration point or higher. Examples of materials include [(Japanese Patent Publication 4-1715)
No. 4, etc.) (see FIG. 4)]. The hysteresis characteristics in the color density-temperature curve of the thermochromic material are shown below in FIGS.
The graph will be described. 4 and 5, the vertical axis represents color density and the horizontal axis represents temperature. The change in color density due to the temperature change progresses along the arrow. Here, A is a point showing the density at the lowest temperature T ₄ (color development / branching temperature) at which the completely decolored state is reached, and B is the density at the highest temperature T ₃ (highest holding temperature) at which the completely colored state can be maintained. C is the minimum temperature T at which the completely decolored state can be maintained.
₂ is the point showing the density at the minimum holding temperature, and D is the point showing the density at the maximum temperature T ₁ (complete coloring temperature) at which the fully colored state is reached. The length of the line segment HG is the temperature width (ΔH) indicating the degree of hysteresis. The conventional thermochromic material described above is used not only in the field of temperature-indicating materials for visualizing an appropriate temperature or a dangerous temperature, but also as a toy that imparts distinctiveness due to thermal discoloration, the nuance of discoloration, unexpectedness, the field of decoration, and any image by overprinting. It has been applied to various fields such as picture books and teaching materials where the temperature is hidden by temperature changes. However, a white-colorless reversible thermochromic material exhibiting the color change characteristics as shown in the above-mentioned drawings (FIGS. 4 and 5) has not yet been disclosed.

Recently, as a heat-sensitive recording material for image formation by a thermal head or the like, an attempt to form a heat-sensitive layer by dispersing microcapsules containing an organic low-molecular substance in a resin medium has been disclosed (special feature. Kaihei 5-116452
No. The microcapsules exhibit a cloudy opaque state and a colorless transparent state depending on the temperature, but the discoloring property is different from that of the thermochromic material described above, and the third state in which the temperature of the colorless transparent state is exceeded is exceeded. That is, in a system in which an intermediate state (translucent state) of the above states is presented and the intermediate state is conceived, the state changes by following a path different from those of the two states. This point will be described with reference to FIG. T
₀ 'following a normal temperature is in the cloudy opaque state, which the temperature T _2' becomes transparent when heated to again T ₀ 'in this state
Even if cooled below and returned to room temperature, it remains as it is. When heated above T ₃ ', it becomes a semitransparent state between the maximum transparency and the maximum opacity, and when the temperature is lowered in this state, It returns to the initial cloudy opaque state without taking the transparent state again. This cloudy opaque state is T ₁ '
After being heated to a temperature between T ₂ ′ and cooled to room temperature, that is, a temperature of T ₀ ′ or less, an intermediate state between transparent and opaque can be obtained. Also, if the transparent material at room temperature is heated to a temperature of T ₃ 'or higher and then returned to room temperature,
It returns to cloudy and opaque again. That is, it assumes both an opaque and transparent state and an intermediate state at room temperature. As described above, the state change due to the temperature change of the microcapsules in the heat-sensitive recording material used for image formation with a thermal head or the like behaves differently from the thermochromic material that causes the above two conventional states to appear alternately. Present.

[0004]

The microcapsules in the above-mentioned heat-sensitive recording material are effective when applied to a system for developing and erasing an image by a thermal head or the like, but are in a transparent state at a temperature of T ₂ '. After that, no matter how much it is cooled, it does not return to the cloudy and opaque state but remains in the transparent state, and in the high temperature region of T ₃ 'or higher, the third state (translucent state) as described above appears. , The color change characteristic due to temperature change is different from the conventional thermochromic material,
It is difficult to use both of them together. The present invention exhibits the same color change characteristics as the above-mentioned conventional thermochromic material, has a reversibility of white and opaque state-colorless transparent state with an applicable hysteresis width (ΔH), and has a conventional thermochromic property. Satisfying the combined use with the material, contributing to the multicoloring of the thermochromic material, and forming a white hiding layer (including an image) to form a lower layer of the hiding layer and / or
Alternatively, by providing a thermochromic or non-thermochromic colored layer (including an image) disposed on the upper layer, a thermochromic light-shielding / translucent microcapsule pigment that can be hidden by temperature change is provided. Is what you are trying to do.

[0005]

The present invention has a melting point of -40.
A crystalline microcapsule pigment having a particle size of 0.1 to 50 μm, containing one or more compounds selected from the group consisting of esters, ethers, and ketones in the range of ℃ to + 90 ° C., The esters are monohydric fatty acids and aliphatic monohydric alcohols or monohydric alcohols having an alicycle and having a total of 13 or more carbon atoms, aliphatic divalent or polyvalent carboxylic acids, and aliphatic monohydric alcohols or fats. An ester having a total carbon number of 18 or more consisting of a monohydric alcohol having a ring, an aliphatic dihydric or polyhydric alcohol or an ester having a total carbon number of 18 or more consisting of an alicyclic dihydric or polyhydric alcohol and a monohydric fatty acid, An ester having a total carbon number of 24 or more consisting of a dihydric alcohol having an aromatic ring and a monovalent fatty acid, a monovalent carboxylic acid having an aromatic ring, and an aliphatic monohydric alcohol or an alicyclic ring Total number of carbon made from the valence alcohol 15
Ester having the total carbon number of 14 or more consisting of the above ester, monovalent carboxylic acid having an aromatic ring and monohydric alcohol having an aromatic ring, total carbon number 15 or more consisting of a monovalent fatty acid and a monohydric alcohol having an aromatic ring And an ester having a total carbon number of 16 or more consisting of a divalent fatty acid and a monohydric alcohol having an aromatic ring, wherein the ethers are
An aliphatic ketone having a total carbon number of 16 or more or an ether having an aromatic ring having a total carbon number of 11 or more, wherein the ketones is an aliphatic ketone having a total carbon number of 10 or more, an aromatic ring or an alicyclic ring having a total carbon number of 10 or more. is made by selected from ketones having, light shielding by the temperature change - with respect to the translucent curve varies with a hysteresis width ([Delta] H), in the course of temperature in the white opaque state is raised, the to reach the temperature T _C state It begins to change and maintains a colorless and transparent state in a temperature range above the temperature T _D , and in the process of decreasing the temperature in the colorless and transparent state, when the temperature T _B lower than the temperature T _D is reached, the state changes. Then, the thermochromic light-shielding / light-transmitting microcapsule pigment that becomes completely white and opaque in the temperature range of T _A or lower is required. Furthermore, T _B is a temperature lower than T _C , and the white opaque state and the colorless transparent state can coexist in the temperature range between T _B and T _C , and further, the hysteresis width (ΔH) Depends on the particle size of the microcapsules, and in a system with a particle size of 1 to less than 2 μm, the particle size is 2
The requirement is that the hysteresis width (ΔH) is larger than that of a system of μm or more, and further that the oil-soluble fluorescent brightening agent is blended in a dissolved or dispersed state in the inclusion.

The above-mentioned thermochromic light-shielding / translucent microcapsule pigment of the present invention is a vehicle containing a conventionally known binder, for example, evaporation drying type (resin / solvent), gelation drying type (emulsion), cooling and solidification. Mold (wax mold),
It is dispersed in a vehicle containing a binder such as an oxidative polymerization type, a thermosetting type, or an ultraviolet curing type, and applied as a coloring material such as printing ink or paint. Here, the amount of the capsule pigment in the total amount of the dried coating film is 10 to 80% by weight, preferably 3%.
0 to 70% by weight can be contained. 10% by weight
If it is less than 80% by weight, it is difficult to visually recognize the effect due to a clear change in state, and the adhesive strength to the binder exceeding 80% by weight is poor. Furthermore, the microcapsule pigment may be blended in a transparent thermoplastic or thermosetting resin to form a sheet-shaped or appropriately-shaped integral molded body for practical use.

Microencapsulation can be carried out by the conventionally known interfacial polymerization method, in situ polymerization method, submerged curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melt dispersion cooling method, suspension in air. There are a turbid coating method, a spray drying method and the like, which are appropriately selected depending on the application, but generally, the interfacial polymerization method and the in situ polymerization method are preferably used, and as the film agent, polyamide, polyurethane, poly Examples thereof include urea, epoxy, polycarbonate, melamine-formalin condensate, urea-formalin condensate.
In addition, an oil-soluble optical brightener, for example, one or more compounds selected from oil-soluble optical brighteners such as coumarin-based, naphthalimide-based, oxazole-based, and thiophene-based brighteners with respect to 100 parts by weight of the inclusion. The fluorescent whitening property can be imparted to the microcapsule pigment itself by dissolving or dispersing 0.001 to 20 parts by weight (more preferably 0.01 to 10 parts by weight). The surface of the microcapsules may be provided with a secondary resin film depending on the purpose to impart durability, or the surface characteristics may be modified for practical use. As described above, a chemically and physically stable pigment can be formed by including a component that causes a state change such as ethers, esters, and ketones in the microcapsules, and the particle diameter is 0.1 to 50 μm.
Within the range, a microcapsule pigment having a particle diameter suitable for the purpose is obtained and put to practical use.

The microcapsule pigment according to the present invention is
The phenomenon in which the white opaque state and the colorless transparent state exhibit tautomerism due to temperature change is presumed as follows. The inclusions described above become crystals in a solid state at a temperature below the freezing point, become a white state by scattering light, and present an opaque state that obstructs the transmission of incident light, while the temperature of the inclusions is higher than the melting point of the inclusions. When it is raised, the inclusion becomes liquid, the transmittance of incident light is increased, and it becomes transparent. The inventor of the present invention changes the hysteresis width (ΔH) depending on the particle size of the state change. That is, it was found that in the system having an average particle size of 1 to less than 2 μm and the system having a particle size of 2 μm or more, the former system has a larger ΔH value than the latter system. The phenomenon described above is
When the particle size is small (1 to less than 2 μm), the volume is decreased, so that the probability that crystal nuclei of the inclusions are generated is reduced.
It is presumed that the freezing point (crystal temperature) is lowered and contributes to the widening of the ΔH value. In the range of the particle diameter of 2 μm or more and 50 μm, the freezing point shows substantially the same freezing point regardless of the particle diameter and shows substantially the same ΔH value, and the ΔH value gives a smaller value than the above system of less than 1 to 2 μm.

Next, the inclusions applied to the present invention will be described. Among the esters applied to the present invention, pentadecyl acetate, n-tridecyl butyrate, as esters having a total carbon number of 13 or more, which consist of a monovalent fatty acid and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring, Butyric acid n-
Pentadecyl, n-nonyl caprylate, n-caprylate
Undecyl, n-lauryl caprylate, n-caprylate
Tridecyl, n-pentadecyl caprylate, cetyl caprylate, stearyl caprylate, n-propyl caprate, n-heptyl caprate, n-undecyl caprate, n-lauryl caprate, n-tridecyl caprate, n-caprate. Pentadecyl, cetyl caprate,
Stearyl caprate, n-undecyl caproate, n-tridecyl caproate, n-pentadecyl caproate, n-nonyl caproate, n-undecyl caproate, stearyl caproate, n-hexyl caprylate,
N-heptyl caprylate, n-octyl caprylate, methyl laurate, n-heptyl laurate, n-pentyl laurate, neopentyl laurate, laurate 2
Ethylhexyl, n-octyl laurate, n-nonyl laurate, n-decyl laurate, n-undecyl laurate, lauryl laurate, n-tridecyl laurate, myristyl laurate, n-pentadecyl laurate, stearyl laurate, Cyclohexylmethyl laurate, methyl myristate, n-pentyl myristate, n-heptyl myristate, n-nonyl myristate, n-decyl myristate, n-undecyl myristate, lauryl myristate, n-tridecyl myristate, myristin Acid myristyl, n-pentadecyl myristate, cetyl myristate, stearyl myristate, cyclohexyl myristate, methyl palmitate, ethyl palmitate, n-propyl palmitate,
N-Pentyl palmitate, neopentyl palmitate, n-heptyl palmitate, n-nonyl palmitate, n-decyl palmitate, n-decyl palmitate, lauryl palmitate, n-tridecyl palmitate, myristyl palmitate palmitate n -Pentadecyl, cetyl palmitate, stearyl palmitate, cyclohexyl methyl palmitate, methyl stearate, n-amyl stearate, n-heptyl stearate, neopentyl stearate, n-octyl stearate, n-nonyl stearate, n-stearate n -Decyl, n-undecyl stearate, n-tridecyl stearate, myristyl stearate, n-stearate
Pentadecyl, cetyl stearate, stearyl stearate, eicosyl stearate, n-docosyl stearate, cyclohexylmethyl stearate, oleyl stearate, isostearyl stearate, cyclohexylmethyl stearate, methyl eicoate, n-amyl eicoate, eicosate Acid n-heptyl, eicoic acid n-octyl, eicoic acid n-nonyl, eicoic acid n-decyl, eicoic acid n-undecyl, eicoic acid n-tridecyl, eicoic acid n-pentadecyl, ethyl behenate, n-amyl behenate. , N-heptyl behenate, neopentyl behenate,
N-octyl behenate, n-nonyl behenate, n-decyl behenate, n-undecyl behenate, n-tridecyl behenate, myristyl behenate, n-pentadecyl behenate, cetyl behenate, stearyl cyclohexyl acetate, 2- Examples thereof include stearyl cyclohexylpropionate and neopentyl octylate.

Examples of esters having a total of 18 or more carbon atoms, which are composed of an aliphatic divalent or polyvalent carboxylic acid and an aliphatic monohydric alcohol or an alicyclic monohydric alcohol, include di-n-butyl sebacate and diadipic acid. n-hexyl, di-n-nonyl oxalate, di-n-decyl oxalate, di-n-undecyl oxalate, dilauryl oxalate, di-n-tridecyl oxalate, dimyristyl oxalate, di-n-pentadecyl oxalate, dicetyl oxalate , Di-n-heptadecyl oxalate, distearyl oxalate, dilauryl malonate, di-n-tridecyl malonate, dimyristyl malonate, di-n-pentadecyl malonate, dicetyl malonate, di-n-heptadecyl malonate, distearyl malonate , Di-n-nonyl succinate, di-n-decyl succinate, di-n-undecyl succinate, succinic acid Lauryl, di-n-tridecyl succinate, dimyristyl succinate, di-n-pentadecyl succinate, dicetyl succinate, diheptadecyl succinate, distearyl succinate, di-decyl glutarate, di-n-undecyl glutarate, dilauryl glutarate. , Di-n-tridecyl glutarate, dimyristyl glutarate, di-n-pentadecyl glutarate, dicetyl glutarate, di-n-heptadecyl glutarate, distearyl glutarate,
Di-n-decyl adipate, di-n-undecyl adipate, dilauryl adipate, di-n-tridecyl adipate, dimyristyl adipate, di-n-pentadecyl adipate, dicetyl adipate, di-n-heptadecyl adipate, di-adipate Stearyl, di-n-docosyl adipate, di-n-decyl pimelic acid, di-n-undecyl pimelic acid, dilauryl pimelic acid, di-n-tridecyl pimelic acid, dimyristyl pimelic acid, di-n-pimelic acid.
Pentadecyl, dicetyl pimelic acid, di-n-pimelic acid
Heptadecyl, distearyl pimelic acid, di-n-decyl suberate, di-n-undecyl suberate, dilauryl suberate, di-n-tridecyl suberate, dimyristyl suberate, di-nonyl sebacate, di-n-decyl sebacate, Di-n-undecyl sebacate, dilauryl sebacate, di-n-tridecyl sebacate, dimyristyl sebacate, di-n-pentadecyl sebacate, dicetyl sebacate, di-n-heptadecyl sebacate, distearyl sebacate, di-suberate di- Pentadecyl, dicetyl suberate, di-n-heptadecyl suberate, distearyl suberate, di-n-decyl azelate, di-n-undecyl azelate, dilauryl azelate, di-tridecyl azelate, dimyristyl azelate, azelai Acid di n-pentadecyl, azelaic acid dicetyl, azelaic acid di n-heptadecyl, azelaic acid distearyl, 1,18 octadecyl methylene dicarboxylic acid di n-octyl, 1,18 octadecyl methylene dicarboxylic acid dicyclohexyl, 1,18 octadecyl methylene dicarboxylic acid Dyneopentyl and the like can be mentioned.

Examples of esters having a total of 18 or more carbon atoms, which are aliphatic dihydric or polyhydric alcohols or alicyclic dihydric and polyhydric alcohols and monovalent fatty acids, include ethylene glycol dicaprylic acid ester and ethylene glycol dicaprin. Acid ester, ethylene glycol diundecanoate ester, ethylene glycol dilaurate ester,
Ethylene glycol ditridecanoate, ethylene glycol dimyristate, ethylene glycol dipentadecanoate, ethylene glycol dipalmitate, ethylene glycol diheptadecanoate, ethylene glycol distearate, 1,3-propanediol dicaprylic acid Ester, 1,3-propanediol dicapric acid ester,
1,3-propanediol diundecanoate,
1,3-propanediol dilaurate, 1,
3-Propanediol ditridecanoate, 1,3
-Propanediol dimyristate, 1,3-
Propanediol dipentadecanoate, 1,3-
Propanediol dipalmitate, 1,3-propanediol diheptadecanoate, 1,3-propanediol distearate, 1,4-butanediol dicaprylate, 1,4-butanediol dicaprate, 1,4-butanediol diundecanoate, 1,4-butanediol dilaurate, 1,4-butanediol ditridecanoate, 1,4-butanediol dimyristate, 1,4-butanediol Dipentadecanoic acid ester, 1,4-butanediol dipalmitic acid ester, 1,4-butanediol diheptadecanoic acid ester, 1,4-butanediol distearic acid ester,
1,5-pentanediol dicapric acid ester, 1,
5-pentanediol diundecanoate, 1,5
-Pentanediol dilaurate, 1,5-pentanediol ditridecanoate, 1,5-pentanediol dimyristate, 1,5-pentanediol dipentadecanoate, 1,5-pentanediol dipalmitate Ester, 1,5-pentanediol diheptadecanoic acid ester, 1,5-pentanediol distearic acid ester, 1,6-hexanediol dicapric acid ester, 1,6-hexanediol diundecanoic acid ester, 1,6- Hexanediol dilaurate, 1,6-hexanediol ditridecanoate, 1,6-hexanediol dimyristate, 1,6-hexanediol dipentadecanoate, 1,6-hexanediol dipalmitate , , 6-hexanediol diheptadecanoic acid ester, 1,6-hexanediol distearic acid ester, 1,7-pentanediol dicapric acid ester, 1,7-pentanediol diundecanoic acid ester, 1,7-pentanediol diester Laurate, 1,7-pentanediol ditridecanoate, 1,7-pentanediol dimyristate, 1,7-pentanediol dipentadecanoate, 1,7-pentanediol dipalmitate, 1, 7-pentanediol diheptadecanoic acid ester, 1,7-pentanediol distearic acid ester, 1,8-octanediol dicapric acid ester,
1,8-octanediol diundecanoic acid ester,
1,8-octanediol dilaurate, 1,
8-octanediol ditridecanoic acid ester, 1,8
-Octanediol dimyristate ester, 1,8-
Octanediol dipentadecanoate, 1,8-
Octanediol dipalmitate, 1,8-octanediol diheptadecanoate, 1,8-octanediol distearate, 1,9-nonanediol dicaprate, 1,9-nonanediol diundecanoate 1,9-nonanediol dilaurate, 1,9-nonanediol ditridecanoate, 1,9-nonanediol dimyristate, 1,9-nonanediol dipentadecanoate, 1,9-nonane Diol dipalmitic acid ester, 1,9-nonanediol diheptadecanoic acid ester, 1,9-nonanediol distearic acid ester, 1,10-decanediol dicaprylic acid ester,
1,10-decanediol dicapric acid ester, 1,
10-decanediol diundecanoate, 1,1
0-decanediol dilaurate, 1,10-
Decanediol ditridecanoate, 1,10-decanediol dimyristate, 1,10-decanediol dipentadecanoate, 1,10-decanediol dipalmitate, 1,10-decanediol diheptadecanoate Ester, 1,10-decanediol distearate ester, 1,5-pentanediol distearate, 1,2,6-hexanetriol dimyristate, pentaerythritol trimyristate, pentaerythritol tetralaurate, 1, 4-cyclohexanediol dimyristyl, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanediol dimyristyl, 1,4-cyclohexanediol distearyl, 1,4-cyclohexanedimethanol dilaurate, 1, - Jimirisuteto etc. cyclohexanedimethanol.

As the esters having a total carbon number of 24 or more, which are composed of a dihydric alcohol having an aromatic ring and a monovalent fatty acid,
Xylylene glycol dicaprylate, xylylene glycol dicaprate, xylylene glycol diundecanoate, xylylene glycol dilaurate, xylylene glycol ditridecanoate, xylylene glycol dimyristate, xylylene glycol Examples thereof include dipentadecanoic acid ester, xylylene glycol dipalmitic acid ester, xylylene glycol diheptadecanoic acid ester, and xylylene glycol distearic acid ester.

Esters having a total carbon number of 15 or more and composed of a monovalent carboxylic acid having an aromatic ring and an aliphatic monohydric alcohol or an alicyclic monohydric alcohol include hexyl 3,5-dimethylbenzoate and 2- Decyl methyl benzoate,
Lauryl 2-methylbenzoate, myristyl 2-methylbenzoate, stearyl 2-methylbenzoate, 4-tert.
-Butyl cetyl benzoate, behenyl 4-cyclohexyl benzoate, myristyl 4-phenyl benzoate, 4-octyl lauryl benzoate, stearyl 3-ethyl benzoate, decyl 4-isopropyl benzoate, stearyl 4-benzoyl benzoate, 4- Stearyl chlorobenzoate,
Myristyl 3-bromobenzoate, Stearyl 2-chloro-4-bromobenzoate, Decyl 3,4-dichlorobenzoate, Octyl 2,4-dibromobenzoate, Cetyl 3-nitrobenzoate, Cyclohexylmethyl 4-aminobenzoate Cetyl 4-diethylaminobenzoate, Stearyl 4-anilinobenzoate, Decyl 4-methoxybenzoate, 4
-Cetyl methoxybenzoate, octyl 4-butoxybenzoate, cetyl 4-hydroxybenzoate, stearyl p-chlorophenylacetate, cetyl p-chlorophenylacetate,
Neopentyl salicylate, stearyl 2-naphthoate,
Examples thereof include cetyl benzylate, stearyl benzylate, decyl 3-benzoylpropionate, stearyl benzoate, myristyl benzoate, cyclohexylmethyl 2-benzoylpropionate, cyclohexylmethyl cinnamate and the like.

Esters having a total carbon number of 14 or more, which are composed of a monovalent carboxylic acid having an aromatic ring and a monohydric alcohol having an aromatic ring, include benzyl salicylate and salicylic acid 4
-Methoxymethylphenylmethyl, 4-chlorophenylmethyl benzoate, benzyl cinnamate, phenyl 4-tert-butylbenzoate, 4-chlorobenzyl 2-methylbenzoate, 4-methoxyphenylmethyl benzoate and the like.

As the esters having a total carbon number of 15 or more, which are composed of monovalent fatty acids and monohydric alcohols having an aromatic ring,
4-Chlorophenylmethyl caprylate, 4-capric acid
Chlorophenylmethyl, 4-methoxyphenylmethyl laurate, 4-methoxyphenylmethyl myristate,
4-Nitrophenylmethyl stearate, capric acid 4
-Methylphenylmethyl, 2-chlorophenylmethyl myristate, 4-chlorophenyl 11-bromolaurate, 4-isopropylphenyl stearate, stearyl 2-naphthoate, cetyl benzylate, stearyl benzylate, benzyl caproate, benzyl palmitate,
Examples thereof include 3-phenylpropyl stearate and phenyl 11-bromolaurate.

Esters having a total of 16 or more carbon atoms, which are composed of a divalent fatty acid and a monohydric alcohol having an aromatic ring, include:
Examples thereof include dibenzyl sebacate, and dineopentyl 4,4′-diphenyldicarboxylate.

Next, the ethers applicable to the present invention will be described. Examples of aliphatic ethers having 16 or more carbon atoms include dioctyl ether, diniethylhexyl ether, didecyl ether, didodecyl ether, ditridecyl ether, ditetradecyl ether, dipentadecyl ether, dihexadecyl ether, diheptadecyl ether. Examples thereof include ether and dioctadecyl ether.

Examples of ethers having an aromatic ring having a total carbon number of 11 or more include benzyl isoamyl ether, diphenyl ether, ethylene glycol diphenyl ether,
Diisopropylbenzyl ether and the like can be mentioned.

Next, the ketones applied to the present invention will be described. Examples of the aliphatic ketones having a total carbon number of 10 or more include 2-decanone, 3-decanone, 4-decanone, 2-
Undecanone, 3-Undecanone, 4-Undecanone,
5-undecanone, 6-undecanone, 2-dodecanone, 3-dodecanone, 4-dodecanone, 5-dodecanone, 2-tridecanone, 3-tridecanone, 2-tetradecanone, 2-pentadecanone, 8-pentadecanone,
2-hexadecanone, 3-hexadecanone, 9-heptadecane, 2-pentadecanone, 2-octadecanone,
2-nonadecanone, 10-nonadecanone, 2-eicosanone, 11-heneicosanone, 2-docosanone, lauron, stearone, cyclodecanone and the like can be mentioned.

As the ketones having an aromatic ring or alicyclic ring having a total carbon number of 10 or more, benzyl acetophenone, benzyl phenyl ketone, n-octadecanophenone, n
-Heptadecanophenone, n-hexadecanophenone,
n-tetradecanophenone, n-tridecanophenone,
Laurophenone, n-undecanophenone, n-decanophenone, 4'-n-octylacetophenone, n-nonanophenone, 4'-n-heptylacetophenone, n
-Octanophenone, 4'-n-hexylacetophenone, 4'-cyclohexylacetophenone, 2-methylbenzophenone, dicyclohexylketone, 4-ter
t-butylpropiophenone, n-heptanophenone,
4'-n-pentylacetophenone, cyclohexylphenylketone, 2-benzylidenecyclohexanone, benzophenone, cyclodecanone, 2-n-heptylcyclohexanone, 2-cyclohexylcyclohexanone,
2- (1-cyclohexyl) cyclohexanone, benzyl n-butyl ketone, 4'-n-butylacetophenone, n-hexanophenone, 4-isobutylacetophenone, cyclopentylphenyl ketone, 4-phenylcyclohexanone, 1-acetothephthalone, 2-acetothephthalone, 4-n-pentylcyclohexanone, benzyl isopropyl ketone, 4'-n-propyl acetophenone, 2 ', 4', 6'-trimethyl acetophenone,
Cyclobutyl phenyl ketone, 2 ', 4'-dimethylacetophenone, 2', 5'-dimethylacetophenone,
4'-ethylacetophenone, isopropyl phenyl ketone, 4'-methylpropiophenone, 1-phenyl-
2-butanone, phenyl n-propioketone, cyclopropylphenyl ketone, phenylpropenyl ketone, 2
-Amino-4'-chlorobenzophenone, 2-amino-
5-chlorobenzophenone, 4-fluorobenzophenone, 2-amino-2 ′, 5-chlorobenzophenone, 4
-Chloro-4'-hydroxybenzophenone, 2-chlorobenzophenone, 4-chlorobenzophenone, 2,
4'-difluorobenzophenone, 4,4'-difluorobenzophenone, 2,4-dichlorobenzophenone,
2,4'-dichlorobenzophenone, 4,4'-dichlorobenzophenone, 2,3,4,5,6, -pentafluorobenzophenone, decafluorobenzophenone, 3
-3'diaminobenzophenone, 3-4 diaminobenzophenone, 4,4'diaminobenzophenone, 2-aminobenzophenone, 4-aminobenzophenone, 3,4
-Dimethoxyphenyl cisetone, 2 ', 3', 4'-trimethoxyacetophenone, 3 ', 4', 5'-trimethoxyacetophenone and the like.

Next, specific examples of the fluorescent whitening agent applied to the present invention will be described. As a coumarin oil-soluble optical brightener,
A 7-triazinylamino-3-phenylcoumarin derivative represented by Chemical Formula 1 below and a 3-phenyl-7-allyltriazolylcoumarin derivative represented by Chemical Formula 2 below are preferably used.

Embedded image (In the formula, A is a phenyl group which may have a water-insoluble group, X is a halogen atom or an amino group, or aliphatic, aromatic, araliphatic, alicyclic, aliphatic heterocyclic and aromatic. A heterocyclic group such as a primary or secondary amine residue, and Y represents a phenyl group, an amino group or an amine residue defined by X.)

Embedded image (In the formula, X is a hydrogen or chlorine atom, R is a lower alkyl group,
A represents an aromatic residue in which two adjacent carbon atoms are bonded to the nitrogen atom of the triazole ring, and the aromatic residue may be substituted with a water-insoluble group. )

As the naphthalimide-based oil-soluble fluorescent whitening agent, compounds represented by the following chemical formula 3 are preferably used.

Embedded image (In the formula, R ₁ = C _n H _{2n + 1} where n = 1 to an integer of 8; R
₂ = C _n H _{2n + 1} where n = 1 to 8 is an integer. )

As the oxazole-based oil-soluble optical brightening agent, compounds represented by the following chemical formulas 4, 5, and 6 are preferably used.

[Chemical 4] (In the formula, _one of R ₁ and R ₂ is H, the other is C _n H _{2n + 1} where n = 1 to an integer of 8 and _{one of} R ₃ and R ₄ is H,
The other is C _n H _{2n + 1,} where n = 1 to an integer of 8. )

Embedded image (In the formula, _one of R ₁ and R ₂ is H, the other is C _n H _{2n + 1} where n = 1 to an integer of 8 and _{one of} R ₃ and R ₄ is H,
The other is C _n H _{2n + 1,} where n = 1 to an integer of 8. )

[Chemical 6] (In the formula, _one of R ₁ and R ₂ is H, the other is C _n H _{2n + 1} where n = 1 to an integer of 8 and _{one of} R ₃ and R ₄ is H,
The other is C _n H _{2n + 1,} where n = 1 to an integer of 8. )

As the thiophene oil-soluble fluorescent whitening agent, the compound represented by the following chemical formula 7 is preferably used.

[Chemical 7] (In the formula, _one of R ₁ and R ₂ is H, the other is C _n H _{2n + 1} where n = 1 to an integer of 8 and _{one of} R ₃ and R ₄ is H,
The other is C _n H _{2n + 1,} where n = 1 to an integer of 8. ) The oil-soluble optical brightener is 0.00001 to 0.2 parts by weight, preferably 0.0 to 1 part by weight of the thermochromic material.
001 to 0.1 part by weight, more preferably 0.005 to
It is used in the range of 0.05 parts by weight.

[0025]

The microcapsule pigment of the present invention has the structure shown in FIGS.
As shown in, the curve plotting the change in transparency due to temperature change changes with a hysteresis width [ΔH (T _F −T _E )], and exhibits a tautomerism between a white opaque state and a colorless transparent state, resulting in a white opaque state. In the process of increasing the temperature, the white opaque state begins to change when the temperature reaches the temperature T _C , becomes completely colorless and transparent in the temperature range of the temperature T _D or higher, and decreases in the colorless and transparent state. In the process, when the temperature T _B lower than the temperature T _C is reached, the colorless and transparent state begins to change and becomes completely white and opaque in the temperature range of the temperature T _A or lower, between the temperature T _B and the temperature T _C. It provides the hysteresis characteristic that the white opaque state and the colorless transparent state can coexist within the temperature range of. The above-mentioned behavior depends on the melting point of the inclusion encapsulated in the microcapsule. That is, below the freezing point, it becomes a crystal in the solid state, scatters light to become a white opaque state, and when heated above the melting point, becomes a liquid state, and the incident light becomes transparent and becomes colorless and transparent. The hysteresis width (ΔH) depends not only on the melting point of the encapsulated substance but also on the same encapsulated substance depending on the particle size of the microcapsule ΔH.
Change the value of. Since the volume is small in the range of the average particle diameter of 1 to 2 μm, the freezing point (crystal temperature) is lowered due to the small probability that the crystal nuclei of the inner substance are generated, which contributes to the widening of the ΔH value and thus the high hysteresis. It is thought to give characteristics (Fig. 1). A system having a particle size of 2 μm or more exhibits substantially the same freezing point regardless of the particle size, and its ΔH value is smaller than that of the system having a particle size of less than 2 μm, and exhibits a behavior of a small hysteresis characteristic (FIG. 2). The behavior of color change and state change due to temperature change of the microcapsule pigment of the present invention described above is similar to the behavior of the color density-temperature curve (FIGS. 4 and 5) of the conventional thermochromic material, and the hysteresis width A thermochromic processed product that changes in various ways can be configured by using both of them by mutual adjustment.

[0026]

【Example】

Example 1 50 parts of n-heptyl palmitate was dissolved by heating at about 90 ° C., and a mixed solution of 30 parts of methyl ethyl ketone and 15 parts of a polyvalent isocyanate resin (Sumitur Bayer Urethane Co., Ltd .: Sumidule L) was added thereto. In addition, it dissolves uniformly. This is mixed in 150 parts of a 5% polyvinyl alcohol (Nippon Gosei Kagaku KK: Gohsenol GM14) aqueous solution, and dispersed using a homomixer until it becomes fine droplets. While maintaining this aqueous suspension at 60 ° C., 50 parts of a 5% aqueous solution of a curing agent (epoxy resin amine adduct, Shell Petroleum Co., Epicure U) was gradually added to the stirring aqueous suspension. 6
Drop the solution over 0 minutes, and after finishing the dropping, raise the solution temperature to 85
The temperature was raised to 0 ° C., and stirring was continued for about 5 hours while maintaining the liquid temperature at 85 ° C. to obtain a dispersion liquid of homogeneous microcapsules having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm). The obtained dispersion was subjected to centrifugal separation treatment and recovered, and the water content was about 4
A 0% microcapsule hydrous composition was obtained. The average particle diameter of the microcapsules is 0.1 μm to 50 μm depending on the stirring power of the homomixer, that is, the rotation speed and stirring time.
Can be arbitrarily set up to, and the same applies to the following embodiments.

Example 2 In the same formulation as in Example 1, the homomixer was rotated at 9000 rpm for 3 minutes, and the particle size distribution was 0.5 to 0.5.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 1.0 μm (average particle size 0.7 μm) were obtained.

Example 3 50 parts of stearyl caprylate and 10 parts of an epoxy resin (Epicote (828) manufactured by Shell Petroleum Co., Ltd. were heated and dissolved at 80 ° C. to form a homogeneous compatible solution, and 10 parts of methyl ethyl ketone was mixed therewith. After that, 10% gelatin aqueous solution 100
The mixture was agitated with a homomixer so as to be dropped into the portion to form fine droplets. Separately prepared curing agent (epoxy resin amine adduct, Shell Petroleum Co .: Epicure U) 10
% Aqueous solution (50 parts) was gradually added dropwise to the aqueous suspension maintained at 65 ° C. while stirring, the liquid temperature was maintained at 80 ° C., and stirring was continued for about 5 hours to obtain a particle size distribution of 4 to 10 μm and average particles. A uniform dispersion liquid of microcapsules having a diameter of about 6 μm was obtained. The dispersion was subjected to centrifugal separation treatment and recovered to obtain a microcapsule hydrous composition having a water content of about 35%.

Example 4 In the same formulation as in Example 3, the homomixer was rotated at 9000 rpm for 3 minutes to give a particle size of 0.5 to 1.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 0 μm (average particle size 0.7 μm) were obtained.

Example 5 A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was prepared in the same manner as in Example 1 except that stearyl laurate was used instead of n-heptyl palmitate. A composition containing microcapsules was obtained.

Example 6 In the same formulation as in Example 5, the homomixer was rotated at 9000 rpm for 3 minutes to give a particle size distribution of 0.5 to 0.5.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 1.0 μm (average particle size 0.7 μm) were obtained.

Example 7 The particle size distribution was 4 in the same manner as in Example 1 except that cetyl caprate was used instead of n-heptyl palmitate.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 10 μm (average particle diameter of about 6 μm) were obtained.

Example 8 In the same formulation as in Example 7, the homomixer was rotated at 9000 rpm for 3 minutes to give a particle size of 0.5 to 1.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 0 μm (average particle size 0.7 μm) were obtained.

Example 9 A microcapsule pigment and a microcapsule having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) were obtained in the same manner as in Example 1 except that n-heptyl palmitate was replaced by dimyristyl glutamate. A capsule-containing composition was obtained.

Example 10 In the same formulation as in Example 9, the homomixer was rotated at 9000 rpm for 3 minutes to give a particle size of 0.5 to 1.
A microcapsule pigment and a microcapsule-containing composition having a particle size of 0 μm (average particle size 0.7 μm) were obtained.

Example 11 A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was prepared in the same manner as in Example 1 except that dilauryl succinate was used in place of n-heptyl palmitate. A composition containing microcapsules was obtained.

Example 12 Microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) in the same manner as in Example 1 except that cyclohexylmethyl stearate was used in place of n-heptyl palmitate. And a microcapsule-containing composition were obtained.

Example 13 A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was prepared in the same manner as in Example 1 except that neopentyl stearate was used in place of n-heptyl palmitate. A composition containing microcapsules was obtained.

Example 14 Instead of n-heptyl palmitate, n-didecyl-
A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) and a microcapsule-containing composition were obtained in the same manner as in Example 1 except that the tellurium was used.

Example 15 A microparticle having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was obtained in the same manner as in Example 1 except that n-ditetradecyl ether was used instead of n-heptyl palmitate. A composition containing a capsule pigment and a microcapsule was obtained.

Example 16 A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was prepared in the same manner as in Example 1 except that 8-pentadecanone was used instead of n-heptyl palmitate. A composition containing microcapsules was obtained.

Example 17 A microcapsule pigment having a particle size distribution of 4 to 10 μm (average particle size of about 6 μm) was prepared in the same manner as in Example 1 except that 9-heptadecane was used instead of n-heptyl palmitate. A composition containing microcapsules was obtained.

Example 18 50 parts of n-heptyl palmitate was heated at about 80 ° C., and 30 parts of methyl ethyl ketone, 15 parts of polyvalent isocyanate resin (Sumijour L manufactured by Sumitomo Bayer Urethane Co., Ltd.), and coumarin were added thereto. A mixed solution of 0.5 part of an oil-soluble optical brightening agent (PY-18, manufactured by Hakkol Chemical Co., Ltd.) is added and uniformly dissolved, and this is formed into microdroplets in 150 parts of a 5% polyvinyl alcohol solution. Dispersed. Then, in the same manner as in Example 1, the particle size distribution was 4 to 10 μm.
m, an average particle diameter of about 6 μm, a dispersion of uniform microcapsules can be obtained, which is recovered by centrifugation and has a water content of about 40.
% Microcapsule hydrous composition was obtained.

Example 19 The particle size distribution was 4 to 10 μm (average particle size) in the same manner as in Example 18 except that an oil-soluble fluorescent whitening agent (Kayalite B) was used in place of the coumarin-based oil-soluble optical brightening agent. A microcapsule pigment having a diameter of 6 μm) and a microcapsule-containing composition were obtained.

Method of Measuring Change in Transparency Due to Temperature Change It is practically difficult to confirm in detail the change from a cloudy opaque state to a colorless transparent state with a microcapsule pigment alone, so that the microcapsule pigment is placed in a vehicle containing a binder. A dispersed ink was used, and a screen-printed material was formed using this ink, and the state change due to temperature change and the color change characteristics were examined. The ink was prepared as follows.
4.0 parts of the water-containing composition of the microcapsule pigments prepared in Examples 1 to 19 were mixed with ethylene vinyl acetate emulsion 5.
A microcapsule-containing aqueous screen ink is prepared by dispersing a dry film consisting of 2 parts, a thickener 0.5 part, a leveling agent 0.2 part and a defoaming agent 0.1 part in a transparent aqueous screen ink vehicle. did. The ink has a lightness value of 2.
Printing was performed using a 109 mesh screen plate on 04 black fine paper to obtain a printed matter having a printing layer with a film thickness of about 25 μm. This film thickness showed almost the same value even when the water-containing composition obtained in each example was used. The change of the microcapsule pigment from the cloudy state to the transparent state due to the temperature change in the printed matter can be visually recognized as a change from white to black. Therefore, by measuring the change of the lightness value due to the temperature change of the printed matter, the behavior of the change from the cloudy opaque state to the transparent state due to the temperature change and its relative whiteness and transparency can be easily measured.

Method for measuring discoloration behavior The printed matter was measured by a color difference meter [TC-3600 type color difference meter, manufactured by Co., Ltd.].
Made by Tokyo Denshoku Co., Ltd.) within a temperature range of 60 ° C / 10 ° C /
The printed matter was heated and cooled at a rate of min. Example 1
In the case of 0, the measurement start temperature was 0 ° C., the temperature was heated to 50 ° C. at a rate of 10 ° C./min, and subsequently, the temperature was cooled to 0 ° C. again at a rate of 10 ° C./min. The lightness values displayed on the color difference meter at each temperature at this time are plotted on a graph to prepare a color change curve as shown in FIG. 1, and T _A , T _B , T _C , T
_D , T _E (midpoint temperature of color density during clouding process), T _F
(Midpoint temperature of color density in the transparent process) and ΔH (line segment EF) were obtained.

Method of Measuring Contrast At the time of measuring the discoloration behavior, for example, in the case of Example 1, the lightness value V _A at 0 ° C. was used as the lightness value in the turbid and opaque state by a color difference meter [TC-3600 color difference meter]. , Manufactured by Tokyo Denshoku Co., Ltd.], and then read the brightness value in the transparent state, and in the case of Example 1, the brightness value V _D at 50 ° C. in the same manner.
The contrast ΔV was calculated as V _A -V _D. Components included in the microcapsule pigment of the present invention, and T _A , T
_B , T _C , T _D , ΔH (line segment EF), V _A , V _D , ΔV
Each value of is shown in Table 1.

[Table 1]

Adaptation Example 1 50 parts of the microcapsule-containing water-containing composition prepared in Example 1 was dispersed in 50 parts of a vehicle for an aqueous screen ink containing an acrylic emulsion as a main component and having a transparent dry film. Got Using the screen ink, screen printing was performed on a black paper with a 109 mesh screen plate on which ABC characters were drawn to obtain a printed matter on which ABC characters were printed. The printed matter had white letters ABC on the black paper at room temperature of about 25 ° C. However, when the printed matter was heated to 40 ° C., the letters ABC disappeared and the entire surface became black. . This state is maintained at room temperature of about 25 ° C. Next, when cooled to 15 ° C or lower, white ABC letters appeared again, and this state was maintained at room temperature of about 25 ° C. Also, this behavior could be repeated many times.

Adaptation Example 2 Microcapsule hydrous composition 50 prepared in Example 10
Parts were dispersed in 50 parts of a vehicle for an aqueous screen ink having a transparent dry film containing an acrylic emulsion as a main component to obtain an aqueous screen ink containing a microcapsule pigment. The screen ink was solid-printed on a black paper having a thickness of 80 μm using a 120-mesh screen plate to obtain a printed matter in which the screen ink was entirely printed on the black paper. This printed matter is white at room temperature of about 25 ° C, and becomes black when heated to 60 ° C.
This state was maintained in an environment of 10 ° C to 50 ° C. Next, when this printed matter is cooled to 0 ° C. or lower, it becomes a white state again, and this state is maintained in an environment of 50 ° C. or lower and can be repeated many times. When the white paper adjusted as described above was printed by the thermal head of the thermal printer of the word processor, black characters could be printed from the white paper, and the printed characters were 1
It was kept in an environment of 0 ° C to 50 ° C. Also, when the printed paper was put in a freezer for about 15 minutes and cooled to 0 ° C. or lower, it became the original white paper, and it could be used repeatedly many times.

Adaptation Example 3 The microcapsule hydrous composition prepared in Example 5 was dried by a spray drying method to obtain a dry powder of microcapsule pigment, and 30 parts of this powder was used as a vinyl chloride / vinyl acetate copolymer resin 30. Parts, xylol 30 parts, and MIBK 40 parts were uniformly dispersed in a vinyl chloride spray ink vehicle to prepare a microcapsule pigment-containing spray ink. When the spray ink was directly spray-coated on the entire surface of a soft vinyl chloride pink molded product and dried at room temperature, the pink molded product became white at room temperature of about 25 ° C. When this white molded product was heated to 50 ° C. or higher, it changed from white to pink, and when heating was stopped and cooled to room temperature, it became white again. This operation can be repeated many times, and the functions such as the discoloration temperature did not become abnormal even after 3 months.

Adaptation Example 4 The microcapsule hydrous composition prepared in Example 14 was dried by a spray drying method to obtain a dry powder of microcapsule pigment.
A spray ink vehicle containing 40 parts of xylol and 40 parts of MIBK was dispersed to prepare a spray ink containing a microcapsule pigment. The spray ink was spray-painted on the window portion of a blue HIPS resin molded into a car, and dried at room temperature to give a white window. When this white window was heated to 35 ° C. or higher, it turned blue and this state was maintained at room temperature of about 25 ° C. Next, when the car was put in ice water at 15 ° C. or lower, only the window part of the car became white again, and this state was maintained at room temperature of about 25 ° C. This operation can be repeated many times, and the functions such as the color changing temperature did not become abnormal even after 3 months.

Adaptation Example 5 The microcapsule hydrous composition prepared in Example 19 was dried by a spray drying method to give a dry powder of microcapsule pigment, and 60 parts of this powder was used as a vinyl chloride / vinyl acetate copolymer resin 40. Part, cyclohexanone 50 parts, Solvesso 100 (aromatic hydrocarbon solvent: Exxon Chemical Co., Ltd.) 5
An oily screen ink containing microcapsule pigments was prepared by uniformly dispersing it in an oily screen ink vehicle consisting of 0 part and 0.1 part of a silicone-based defoaming agent. Using the oil-based screen ink, a white eye portion was screen-printed on a black eye portion on a vinyl chloride sheet on which a fish picture was drawn with a non-discoloring ink. At room temperature, this print had eye-catching, as if it were alive, but when heated above 40 ° C, the white eyes disappeared and it looked like a dead fish. This state is maintained at room temperature of about 25 ° C. Next, when cooled to 15 ° C or lower, white eyeballs appeared again, and this state was maintained at room temperature of about 25 ° C. Also, this behavior could be repeated many times.

Adaptation Example 6 40 parts of thermochromic pigment showing blue at 45 ° C. or lower and colorless at 50 ° C. or higher, 60 parts of ethylene vinyl acetate emulsion,
A thermochromic water-based screen ink obtained by uniformly stirring 2 parts of a thickener and 1 part of a defoaming agent was used to screen print the letters ABC on a white high-quality paper using a 180 mesh screen plate. Thermochromic shading-translucency consisting of 60 parts thermochromic shading-translucent microcapsule pigment prepared in Example 3, 40 parts ethylene vinyl acetate emulsion, 2 parts thickener, 1 part defoamer on top The screen ink was solid-printed on the entire surface using an 80-mesh screen plate to obtain a white thermochromic print. The printed matter was white at room temperature of 24 ° C., but when heated to 40 ° C., the screen ink on the upper surface changed from white to colorless, and the ABC letters drawn in blue on the lower surface were printed. It appeared.
Further, when the printed matter was heated to 50 ° C., the letters ABC were erased and the entire surface became white, and even if it was heated to 50 ° C. or higher, no change was observed and the white state was maintained. Further, when the printed matter heated to 50 ° C. or higher was gradually cooled, when it was cooled to 45 ° C., blue ABC letters appeared again and up to 33 ° C. blue letters appeared.
When the temperature is cooled to below ℃, the letters ABC of blue color gradually disappears, and at 28 ℃, it returns to a completely white state. The printed matter in the white state was white at room temperature of 24 ° C., and even when cooled to 10 ° C., the white state was maintained and maintained without any change. The printed matter as described above can repeat the above-mentioned behavior by repeating heating and cooling.

[0054]

INDUSTRIAL APPLICABILITY The microcapsule pigment of the present invention determines a thermochromic material (electron-donating color-developing organic compound, electron-accepting compound), which has been widely used in the past, and the temperature at which a color reaction between the two occurs. Since the state changes with a hysteresis characteristic similar to that of a microcapsule pigment in which a homogeneous compatible solution of three essential components of an organic reaction medium is encapsulated in a microcapsule, the combination property is satisfied. Since the conventional thermochromic material has a new phase change from white and opaque to colorless and transparent, it can be applied in various ways in combination with these materials. For example,
A colored layer (thermochromic colored layer or non-discolorable colored layer) is overprinted on the upper layer and / or the lower layer of the white base layer in which the microcapsule pigment of the present invention is dispersed and fixed to a film-forming material, and is revealed by a temperature change. It is possible. The base layer or the colored layer in the above may be an image, and further, a combination in which the hysteresis width is variously changed is possible.

[Brief description of drawings]

FIG. 1 is a graph showing the behavior of the thermochromic light-shielding-translucent microcapsule pigment of the present invention due to temperature change.

FIG. 2 is another graph showing the behavior of the thermochromic light-shielding / light-transmitting microcapsule pigment of the present invention due to temperature change.

FIG. 3 is a graph showing a behavior of a microcapsule in a heat-sensitive recording material due to a temperature change.

FIG. 4 is a graph showing a color density-temperature curve of a color-memory thermochromic material that exhibits large hysteresis characteristics and changes color with temperature change.

FIG. 5 is a graph showing a color density-temperature curve of a thermochromic material that changes color with a small hysteresis characteristic due to temperature change.

[Explanation of symbols]

T _A fully opaque temperature T _B Minimum temperature for maintaining fully transparent state T _C Maximum temperature for maintaining fully opaque state T _D Completely transparent temperature T _E Temperature at midpoint in opaque process T _F Temperature at midpoint in transparent process _TG temperature T temperature of the midpoint in color density in the _H coloring process V _a cloudy opaque state when the brightness value V _D lightness value at transparent state ΔH hysteresis width T ₁ fully colored temperature T of the midpoint in color density in the decoloring process ₂ Minimum holding temperature in decolored state T ₃ Maximum holding temperature in colored state T ₄ Complete decoloring temperature

Claims (4)

[Claims] 1. A particle size including a crystalline compound having a melting point in the range of −40 ° C. to + 90 ° C. and selected from one or more kinds of compounds selected from esters, ethers and ketones and having a particle size of 0.1 to 0.1. A microcapsule pigment of 50 μm, wherein the esters include a monohydric fatty acid and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring, and the total carbon number is 13
Having an ester, an aliphatic dihydric or polyhydric alcohol or an alicyclic ring, which is composed of the above ester, an aliphatic dihydric or polyhydric carboxylic acid and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring, and having a total of 18 or more carbon atoms Esters having a total of 18 or more carbon atoms consisting of dihydric and polyhydric alcohols and monovalent fatty acids, esters having a total of 24 or more carbon atoms consisting of dihydric alcohols having an aromatic ring and monovalent fatty acids, monovalent esters having an aromatic ring Ester having a total carbon number of 15 or more consisting of a carboxylic acid and an aliphatic monohydric alcohol or an alicyclic monohydric alcohol, and a total carbon number of 14 or more consisting of a monovalent carboxylic acid having an aromatic ring and a monohydric alcohol having an aromatic ring. Carbon number consisting of ester, monovalent fatty acid and monohydric alcohol having aromatic ring
5 or more esters, and esters having a total carbon number of 16 or more consisting of a divalent fatty acid and a monohydric alcohol having an aromatic ring, wherein the ethers are aliphatic ethers having a total carbon number of 16 or more or total carbon numbers of 11 The above ketones are selected from ethers having an aromatic ring, and the above-mentioned ketones are selected from aliphatic ketones having a total carbon number of 10 or more and ketones having an aromatic ring or alicyclic ring having a total carbon number of 10 or more.
With respect to the translucency curve, the temperature changes in a hysteresis width (ΔH), and in the process of increasing the temperature in the white opaque state, when the temperature T _C is reached, the above state starts to change, and the temperature T
_In the temperature range above _D , the colorless and transparent state is maintained, and in the colorless and transparent state, the temperature T
_{When a} temperature T _B lower than _D is reached, the state begins to change,
_A thermochromic, light-shielding and translucent microcapsule pigment which becomes completely white and opaque in a temperature range of temperature T _A or lower. Wherein said T _B is the temperature lower than T _C, T _B
And in a temperature range between T _C, the white opaque state and a colorless transparent state can coexist claim 1 thermochromic shielding according - translucent microcapsule pigment. 3. The hysteresis width (ΔH) depends on the particle size of the microcapsules, and a system having an average particle size of 1 to less than 2 μm has a hysteresis width (ΔH) greater than that of a system having a particle size of 2 μm or more.
The thermochromic light-shielding-translucent microcapsule pigment according to claim 1, wherein H) is large. 4. The thermochromic light-shielding / light-transmitting microcapsule pigment according to claim 1, wherein an oil-soluble fluorescent whitening agent is mixed in the encapsulated material in a dissolved or dispersed state.