JP2001109021A - Recording display material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording display material which is capable of making recording and reversible displaying by thermal recording and electric stimuli without providing the display material with cells and is capable of forming color images of high quality with high sharpness. SOLUTION: The recording display material provided with a recording display layer containing microcapsules including color developing and discoloring components on a base contains at least two kinds of the microcapsules which include the color developing and discoloring components to cause color development and discoloration with the electric stimuli of the intensity varying from each other and consist of wall materials changed in electrical conductivity by the stimuli of the intensity different from each other in the recording display layer. (1) The microcapsules which include the color materials to cause the color development at a high oxidation potential and are changed in the electric conductivity at a low temperature, (2) the microcapsules which include the color material to cause the color development at an intermediate oxidation potential are changed in the electrical conductivity at a middle temperature and (3) the microcapsules which include the color materials to cause the color development at a low oxidation potential and are changed in the electrical conductivity at a high temperature are preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor recording / display material capable of recording or reversible display.
The present invention relates to a recording / display material capable of recording and displaying multi-colors by using a plurality of compounds exhibiting electrochromism that develop colors by different electrical stimuli as color changing components.

[0002]

2. Description of the Related Art As recording materials have been improved in performance, there has been a demand for recording / display materials capable of not only recording by color development but also reversible display of color development / decoloration. In recent years, compounds that exhibit electrochromism have attracted attention as materials capable of reversible display of color development and decoloration, and these compounds have the property of developing, decoloring, or discoloring by electrical stimulation, It is used for

[0003] Recorded with a material that changes color by electrical stimulation,
When configuring a display material, for example, in the configuration of a display device, a display surface is divided into fine cells by a material such as glass having no conductivity, and a compound exhibiting electrochromism is arranged in each cell. Thus, display is performed by applying an electrical stimulus to each desired cell to cause discoloration. In such a display element, since the size of a pixel is limited to the size of a cell, from the viewpoint of image sharpness,
Although it can be used for large screen displays,
As a display material, there is a problem that it is not suitable as a means for displaying a satisfactory high-quality image, and improvement has been desired.

As a writing means for achieving high image quality, various heat-sensitive recording materials, such as an infrared laser, which directly heat and react with digital signals according to an image signal to form an image have been proposed. A method to which such writing means can be applied is also being studied.

[0005] When a full-color image is formed,
In the case of display images, color filters and color proofs, etc., it is necessary to provide a plurality of recording layers of different hues.Therefore, there is a problem that there is a limit in reducing the thickness of the recording layer. From the viewpoint of the structure, improvement of the image quality by further thinning is being studied.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to use a plurality of types of electrochromic compounds as coloring materials without providing cells in a display material. Another object of the present invention is to provide a recording / display material capable of performing writing (recording) and reversible display by electrical stimulation and forming a high-quality color image with high sharpness.

[0007]

As a result of the study, the present inventors have found that a plurality of types of different coloring and discoloring components can be converted into electrically conductive materials by using different materials having different thermal responsiveness and by applying thermal stimuli of different intensities. The present inventors have found that the above object can be achieved by enclosing the microcapsules in a microcapsule made of a wall material that changes, and completed the present invention. That is, the recording / display material of the present invention is characterized in that it contains microcapsules made of a wall material which contains color-forming and color-changing components and whose electrical conductivity changes upon stimulation. Here, the electrical conductivity may be ionic conductivity or electronic conductivity. In a preferred embodiment, the stimulus is a thermal stimulus, and the color-forming or discoloring component is a compound exhibiting electrochromism.

A typical constitution of the recording / display material of the present invention is as follows. A recording / display material comprising a support, on which a conductive layer, a recording / display layer and a transparent conductive layer are sequentially provided. The recording / display layer is dispersed in a binder to form a color,
It is characterized by including a microcapsule containing a wall material that contains a discoloration component and changes its electrical conductivity by stimulation.

In the present invention, in the recording / display layer, a component which develops or discolors a plurality of types of microcapsules using a material whose electrical conductivity changes by stimulation as a wall material (hereinafter referred to as a coloring material, as appropriate). The color material existing in the portion where the stimulus of the specific intensity is not applied is protected by the microcapsule wall, or the predetermined electrical stimulus is not applied, so that the color is generated. Alternatively, only when the microcapsule wall material of a portion to which a thermal stimulus of a specific strength is applied without discoloration has, for example, increased electrical conductivity and a potential applied at that time is compatible with the component, the coloring material is supplied by the energization. Color development and discoloration can be caused. Therefore, by selectively applying different thermal stimuli or electrical stimuli to the color materials included in a plurality of types of microcapsules existing in the same layer, the color materials can be arranged in an arbitrary portion of the microcapsules. Only the applied coloring material is colored to form a color image. Specifically, if a compound showing electrochromism that develops at different potentials is used as a plurality of types of coloring materials, only a change in the hue of the desired coloring material can be achieved by a change in the electrical conductivity of the capsule wall and the applied potential. Can be raised.

[0010] A wall material of a different kind and having a different glass transition temperature, which uses a thermal stimulus as a stimulus to the capsule wall, each of which has a glass transition temperature higher than room temperature, has a nonconductive polymer part and a conductive material. If a microcapsule wall material containing a conductive polymer part is used, the capsule wall at room temperature shows material impermeability, while only the desired wall material shows material permeability above its glass transition temperature, and the function of the conductive polymer part Therefore, by selecting a combination of the above-mentioned coloring material and this wall material, a coloring material having an arbitrary hue can be developed and can be suitably used in the present invention.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the recording / display layer has a microcapsule formed of a wall material whose electrical conductivity changes by stimulation and enclosing a color material whose hue changes by electrical stimulation. These microcapsules exhibit a material permeability due to a difference in temperature (heat energy), and further, have a change in electric conductivity. In order to show material permeability due to a difference in energy such as temperature or light, for example, the glass transition temperature (T
It is preferable to form microcapsules having different g) or microcapsules having different crosslink densities of polymers constituting the wall material of the microcapsules in correspondence with the color material compound to be included. A recording / display material capable of forming a color image by developing an arbitrary hue using these will be described with reference to examples.

As the plural kinds of coloring materials of the present invention, the following electrochromic compounds having different oxidation potentials are used. Hereinafter, the electrochromic compound that forms a color at a low oxidation potential will be referred to as E ₁ , the electrochromic compound that forms a color at a medium oxidation potential will be referred to as E ₂ , and the electrochromic compound that forms a color at a high oxidation potential will be referred to as E ₃ .
It is possible to develop multiple colors only by the difference in oxidation potential,
The low oxidation potential only E ₁ is colored, E ₁ and E at medium oxidation potential
₂ is colored, all E ₁ and E ₂ and E ₃ in the high oxidation potential is colored. That is, when color materials having different oxidation potentials are used, a plurality of hues can be obtained by controlling the applied electric energy. However, and be developed with a combination of E ₁ and E ₃ in this manner, only E _2, or can not be developed only E _3, Therefore, there is a limit to obtain hue, good full-color images You can't get it.

On the other hand, a method of using microcapsules having different thermal responsiveness for forming a multicolor image is disclosed in Japanese Patent Application No. Hei 10-205478 previously proposed by the present inventors. Similarly, a method using microcapsules that are expressed by thermal stimuli having different electrical conductivity is also conceivable. Less than,
A microcapsule that becomes electrically conductive at low energy is T
₁ , microcapsules that become electrically conductive at medium energy are represented by T ₂ , and microcapsules that become electrically conductive at high energy are represented by T ₃ . When microcapsules having different thermal responsiveness are encapsulated using three-color electrochromic compounds having little difference in oxidation potential, it is possible to form a multicolor by only a difference in applied energy. Electrochromic compound entering the T ₁ at low energy is colored.
Color development of T ₁ and T ₂ occurs at medium energy, and color development of T ₁ , T ₂ , and T ₃ occurs at high energy (at this time, it is assumed that a potential necessary for color development is given). However, in this method, it is not possible to develop a color of a combination of T ₁ and T ₃ , or to develop only T ₂ or only T ₃ .

The present inventors have found a method for achieving full-color display by combining these coloring materials and wall materials by utilizing these characteristics. That is, by combining such electrochromic compounds E _{1 to} E ₃ as a coloring material and the microcapsules T _{1 to} T ₃ as a microcapsule wall material, simple full-color recording / display can be achieved. Table 1 below shows methods of combinations of E _{1 to} E ₃ and T _{1 to} T ₃ .

[0015]

[Table 1]

That is, (1) a color developed by a high potential,
A microcapsule containing a discoloring component and having a low electrical conductivity at low temperature as a wall material; (2) a microcapsule containing a color developing at a medium potential and a discoloring component and having an electrical conductivity varying at a medium temperature as a wall material; And (3) a microcapsule containing a coloring and discoloration component that develops a color due to a low potential and having a high electrical conductivity at high temperature as a wall material.

The relationship between the input energy and the output (color) will be described with reference to FIG. FIG. 1 shows a combination of the heat energy and the oxidation potential, and is tentatively divided into the regions (a) to (i) as the coloring regions. For composition 1 shown in Table 1, but includes a E ₁ that develops color at a low oxidation potential, microcapsules T ₃ the high energy not applied does not exhibit electrical conductivity. Therefore, when high thermal energy is applied under the condition of low oxidation potential, FIG.
Only (a) develops color. Table composition 2 shown in 1 is a combination of microcapsules T ₂ showing the E ₂ and when the medium energy consuming electrical conductivity develops color at medium oxidation potential, in this combination, the thermal energy of the medium in the medium oxidation potential conditions Is applied, (b) in FIG. 1 is colored. A combination of microcapsules T ₁ showing the electrical conductivity E ₃ and the low-energy colored in the same compositionally 3 high oxidation potential, in FIG. 1 when this combination imparts low thermal energy under conditions of low oxidation potential (C) develops color.

Similarly, by controlling the temperature and the oxidation potential,
Color development in the areas (d), (e) and (f) is also possible.
For example, when the high oxidation potential is set under the medium temperature condition, the regions (b), (c), and (f) are colored. b) and (d)
When a high oxidation potential is set under a high temperature condition, all of the regions (a) to (f) are colored. on the other hand,
In the regions (g), (h), and (i), the combination of the input energies is inappropriate and the color does not develop.

[0019] In the combination of Table 1, the electrochromic compounds cyan color as a coloring material E _1, the electrochromic compounds magenta color as E _2, E
_When using an electrochromic compound that develops yellow as ₃ , each microcapsule is independently cyan,
Since magenta and yellow colors are developed, full color development is possible by freely selecting these combinations. In other words, in the above description, cyan develops at low oxidation potential, high temperature, medium oxidation potential, magenta at medium temperature, high oxidation potential, yellow at low temperature, and high oxidation potential at medium temperature condition. In this case, the color becomes red by magenta and yellow, and when the medium oxidation potential is set at a high temperature condition, blue color is generated by cyan and magenta. When the high oxidation potential is set at a high temperature condition, the region (a) (F) all develop a color to form a black image.

As shown in FIG. 2, these microcapsules may be provided with separate color-forming layers so that each layer independently develops cyan, magenta and yellow colors. Since they are independent for each capsule, they can be used evenly dispersed in one recording layer, but in any case, full color development is possible by freely selecting these combinations. .

At the time of decoloring, a reduction wave is applied under the condition that T ₃ shows electric conductivity, that is, at a high temperature condition where all the microcapsule wall materials show electric conductivity, so that the coloring material of all layers is formed. Is reduced and decolorized.

In order to cause a change in electric conductivity due to a difference in temperature (thermal energy), for example, a conductive polymer of ethylene oxide or propylene oxide is contained as a polymer constituting a wall material of a microcapsule. (Doping) is preferred. That is, the microcapsule wall material according to the present invention preferably has thermal responsiveness, and is preferably a mixture of an insulating polymer component and a conductive polymer component in a well-balanced manner. It is preferably about 1 to 1/20, particularly preferably 5/1 to 1/5. When the amount of the insulating polymer component is larger than a predetermined amount, the conductivity does not change even when the stimulus is applied, and when the amount is too small, the conductivity is always expressed.

The electrical conductivity may be ionic conductivity or electronic conductivity. The wall material that constitutes these microcapsules is stimulated by selecting a polymer that shows material permeability at high energy, a polymer that shows material permeability at intermediate energy, and a polymer that shows material permeability at low energy. Responsiveness can be controlled. These polymers are described in the above-mentioned Japanese Patent Application No. 10-205478, paragraph [0].
013] to paragraph [0064].

It is desirable that the polymer exhibiting substance permeability at high energy is formed from a polyvalent isocyanate represented by the following general formula (2), or an aromatic polyvalent isocyanate and methylene diisocyanate.

General formula (2)

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In the general formula (2), R, R ′, R ″
Each independently represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkylthio group, a dialkylamino group, an acyloxy group, or an arylthio group. Among these, a hydrogen atom, an alkyl group, and an alkoxy group are more preferable in terms of high reactivity of polyvalent isocyanate with water and ease of synthesis.

Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group,
Isobutyl group, sec-butyl group, t-butyl group, n-
Hexyl group, n-octyl group, 2-ethylhexyl group,
n-dodecyl group and the like.
The straight-chain alkyl group of 4 is preferable, and a methyl group and an ethyl group are more preferable.

Examples of the aryl group include a phenyl group, a 4-methoxyphenyl group, a 2-chlorophenyl group, a 4-isopropylphenyl group, a 3-dimethylaminophenyl group,
-T-octylphenyl group, 2,4-dichlorophenyl group, naphthyl group and the like.
The aryl group of 8 is preferable, and a phenyl group and a 4-methoxyphenyl group are more preferable.

Examples of the aralkyl group include a benzyl group, a phenethyl group, a 4-methoxyphenylmethyl group, a 2,4-dichlorophenylmethyl group, an α, α-dimethylbenzyl group and a 2,4-dichlorophenylethyl group.
Among them, an aralkyl group having 7 to 18 carbon atoms is preferable, and a benzyl group and a phenethyl group are more preferable.

As the alkenyl group, an ethenyl group, 1-
Propenyl group, 2-propenyl group, 2-butenyl group, 1
-Butenyl group, 1-hexenyl group, 2-dodecenyl group and the like, among which an alkenyl group having 2 to 4 carbon atoms is preferable, and an ethenyl group and 1-propenyl group are more preferable. Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 3-hexynyl group, a 2-dodecynyl group, and among them, an alkynyl group having 2 to 4 carbon atoms is preferable. , An ethynyl group and a 1-propynyl group are more preferred.

Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group, an n-butoxy group, an n-hexyloxy group, a 2-ethylhexyloxy group and a 3,5,5-trimethylhexyloxy group. , N-undecyloxy group and the like.
4 to 4 straight-chain alkoxy groups are preferable, and a methoxy group and an ethoxy group are more preferable.

The aryloxy group includes phenoxy, naphthoxy, 3-methylphenyloxy, 2-
Examples include a methoxyphenyloxy group, a 2,4-dichlorophenyloxy group, a 2-methyl-4-methoxyphenyloxy group, a 2-ethoxy-3-cyanophenyloxy group, and among them, aryloxy having 6 to 10 carbon atoms is preferable. Groups are preferred, and a phenoxy group and a 2-methoxyphenyloxy group are more preferred.

As the alkylthio group, a methylthio group,
Examples include an ethylthio group, an n-propylthio group, an isopropylthio group, an n-butylthio group, an n-octylthio group, and a 2-ethylhexylthio group.
To 4 are preferred, and a methylthio group is more preferred. As the arylthio group, a phenylthio group,
A 4-methoxyphenylthio group, a 3-methylphenylthio group, a 2-thiomethylphenylthio group, a 4-chlorophenylthio group, a 2-methylphenylthio group, and the like. Among them, an arylthio group having 6 to 10 carbon atoms Are preferable, and a phenylthio group and a 4-methoxyphenylthio group are more preferable.

Examples of the dialkylamino group include dimethylamino, diethylamino, N, N-di-n-butylamino, N, N-di-n-octylamino, N-methyl-N-octylamino, Examples thereof include an N, N-dineopentylamino group, among which a dialkylamino group having 2 to 9 carbon atoms is preferable, and a dimethylamino group and a diethylamino group are more preferable.

As the acyloxy group, an acetyloxy group, a propanoyloxy group, an n-butanoyloxy group,
Isobutanoyloxy group, n-hexanoyloxy group,
Octanoyloxy, 2-ethylhexanoyloxy, benzoyloxy, 3-methylbenzoyloxy, 4-methoxybenzoyloxy, 2,4-dichlorobenzoyloxy, phenylacetyloxy, cinnamyloxy, etc. And, among them, carbon number 2
To 9 acyloxy groups are preferred, and an acetyloxy group;
A phenylacetyloxy group is more preferred.

R, R 'and R "may be the same or different, and may be mutually connected to form a ring.

P is the number of methylene groups between the benzene ring and the isocyanate group, and represents an integer of 1 to 3. In particular, when producing microcapsules, p is preferably 1 from the viewpoint that a polymer network obtained by reacting with water is stronger. q is the number of isocyanatoalkyl groups substituted on the benzene ring, and represents an integer of 3 to 6. That is, the polyvalent isocyanate compound is characterized by having three or more isocyanatoalkyl groups on one benzene ring. If the number is less than 3, a higher-order network cannot be formed at the time of polymerization. When producing microcapsules, q is preferably 3 from the viewpoint that formation of a polymer network by reaction with water proceeds sufficiently. Also,
The substitution position of the isocyanatoalkyl group is preferably at the 1,3,5 position when q is 3, and is preferably at the 1,2,4,5 position when q is 4. .

R, s and t are the numbers of the substituents R and R′R ″, and each represents an integer of 0 or 1 such that q + r + s + t is 6. The following is a general formula (2). Specific examples of the polyvalent isocyanate compound are shown below, but the present invention is not limited thereto.

[0039]

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[0040]

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The polyvalent isocyanate compound represented by the general formula (2) can be produced by a known method. For example, as shown in JP-A-55-167269, it can be produced by utilizing a reaction between a corresponding polyamine compound and phosgene. Also, Japanese Patent Application Laid-Open No. Sho.
No. 45, JP-A-52-46042, it can be produced by utilizing a reaction between a polyvalent haloalkyl compound and a metal salt of cyanic acid. As an example,
The synthesis method by reaction of the polyvalent haloalkyl compound of Exemplified Compound (1) -4 with a metal salt of cyanic acid is shown below.

(Synthesis of Exemplified Compound (1) -4)

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In the formula, M is a metal element such as Na, K, and Ag. If necessary, a metal iodide such as potassium iodide and a quaternary ammonium salt such as tetrabutylammonium iodide may be used in combination. The reaction can be accelerated.
The benzene derivative having a halogenated alkyl group as a raw material can be usually obtained by a known synthesis method. For example, as shown in the above synthesis example, a benzene derivative having a methyl halide group can be obtained by a halomethylation reaction or the like in which formaldehyde and hydrogen halide act on an aromatic compound.

Examples of the aromatic polyisocyanate include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, and naphthalene-isocyanate.
1,4-diisocyanate, diphenylmethane-4,
4'-diisocyanate, 3,3'-dimethoxy-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-
1,4-diisocyanate, xylylene-1,3-diisocyanate, 4-chloroxylylene-1,3-diisocyanate, 2-methylxylylene-1,3-diisocyanate, 4,4′-diphenylpropane diisocyanate, 4,4 '-Diphenylhexafluoropropane diisocyanate and the like.

The polyvalent isocyanate compound or aromatic isocyanate represented by the general formula (2) may be used alone or in combination of two or more. Or,
Other polyvalent isocyanate compounds can be used in combination. Other polyvalent isocyanate compounds that can be used in combination with the polyvalent isocyanate compound represented by the general formula (2) or the aromatic isocyanate include xylylene diisocyanate and its hydrogenated product, isophorone diisocyanate, hexamethylene diisocyanate, ,
Aliphatic isocyanates such as 3,5-tris (isocyanatomethyl) cyclohexane, multimers thereof (buret or isocyanurate, polymer mixture), and adducts of polyhydric alcohols such as trimethylolpropane; Examples include adducts of polyhydric phenols such as bis (4'-hydroxyphenyl) propane. These polyvalent isocyanates are well-known in books (Polyurethane Handbook edited by Keiji Iwata)
Nikkan Kogyo Shimbun (1987)).

Next, as the polymer constituting the wall material of the microcapsule, the polymer having material permeability at intermediate energy may be a polymer such as gelatin, polyurea, polyurethane, polyimide, polyester, polycarbonate, melamine and the like. These polymers can be microencapsulated as a wall material by a conventionally known method.

Next, as a polymer in which the polymer constituting the wall material of the microcapsule exhibits material permeability at low energy, at least one kind of (A) molecule has one active hydrogen and the average molecular weight is It is desirable to use a polymer obtained by polymerizing an isocyanate compound containing an adduct of 500 to 20,000 compounds and (B) a polyfunctional isocyanate having two or more isocyanate groups in the molecule.

Hereinafter, this polymer will be described. The compound (A) having one active hydrogen in the molecule and having a molecular weight of 500 to 20,000 will be described. Examples of the functional group having active hydrogen include a hydroxyl group, an amino group, and a carboxyl group. Of these, a hydroxyl group and an amino group are particularly preferred. The compound having such active hydrogen and having a molecular weight of 500 to 20,000 is not particularly limited, and examples thereof include polyethers and polyesters having active hydrogen at one end.
Examples thereof include polymers of polyamide, polyurea, polyurethane, polysiloxane, and vinyl monomers (hereinafter, referred to as vinyl polymers). Of these, polyethers, polyesters, polysiloxanes, and vinyl polymers are particularly preferred from the viewpoint of the solubility of the compound during encapsulation.
When the molecular weight is smaller than 500, fogging increases due to the introduction of these compounds. On the other hand, if the molecular weight is more than 20,000, it becomes difficult to synthesize the compound, and the viscosity becomes high, so that it is difficult to prepare a liquid during encapsulation and to form a capsule.

More specifically, examples of the polyether include polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polystyrene oxide, polycyclohexylene oxide, and poly (ethylenethioglycol). Examples of the polyester include polycaprolactone. These compounds are, for example, ring-opening-polymerized cyclic compounds such as ethylene oxide and propylene oxide using alcohols, alkoxides, carboxylic acids, and carboxylate salts as polymerization initiation terminals, or caprolactones using alcohols, alkoxides, and the like as polymerization initiation terminals. It is obtained as a polyether or polyester having a hydroxyl group at one end. It is also possible to convert this terminal hydroxyl group into a terminal amino group, carboxyl group or the like by a known reaction. Further, compounds in which only one active hydrogen of polyether or polyester having active hydrogen at both terminals is converted into an ether group, an ethesyl group, or the like can be used. As the polysiloxane, for example, a polydimethylsiloxane derivative having a hydroxyl group at one end can be used.

A vinyl polymer (for example, poly (meth) acrylate, polystyrene, poly (meth) acrylamide, etc.) can also be used. Such a compound is obtained as a vinyl polymer having a hydroxyl group and a carboxyl group at one end by subjecting a vinyl monomer to radical polymerization in the coexistence of a mercapto compound such as mercaptoethanol and mercaptoacetic acid and a radical polymerization initiator. If necessary, these functional groups can be converted to amino groups and the like using known reactions. Examples of vinyl polymerizable monomers include, for example, (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth)
Acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, chloroethyl (meth) Acrylate, allyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (Meth) acrylate, naphthyl (meth) acrylate
Etc.),

(Meth) acrylamides, for example, (meth) acrylamide, N-alkyl (meth) acrylamide (for example, the alkyl group is a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, an octyl group , An ethylhexyl group, a cyclohexyl group, a hydroxyethyl group, a benzyl group, etc.), N-aryl (meth) acrylamide (for example, phenyl group, naphthyl group, hydroxyphenyl group, etc.), N, N
-Dialkyl (meth) acrylamide (as the alkyl group, for example, a methyl group, an ethyl group, a butyl group, an isobutyl group, an ethylhexyl group, a cyclohexyl group, etc.),
N, N-diaryl (meth) acrylamide (the aryl
A phenyl group), N-methyl-
N-phenyl (meth) acrylamide, N-hydroxyethyl-N-methyl (meth) acrylamide, etc .: vinyl esters such as vinyl acetate, vinyl butyrate, vinyl isobutylate, vinyl acetoacetate
G, vinyl benzoate, etc .: styrenes such as styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, methoxystyrene, dimethoxystyrene, Chlorostyrene, dichlorostyrene, bromostyrene and the like: (meth) acrylonitrile, (meth) acrylic acid, polyvinyl methyl ether and the like.

The repeating unit of these compounds may be of one type or a copolymer comprising two or more types of repeating units. These compounds may also have a melting point,
In such a case, a compound having a melting point of 40 to 180 ° C is particularly preferable. Examples of the compound having such a melting point include polyethylene oxide, polystyrene oxide, and polycaprolactone. Since this melting point varies depending on the molecular weight, it cannot be said unconditionally. For example, polyethylene oxide has such a melting point when the molecular weight is about 1,000 or more.

Among these, the monoethers of polyethylene oxide and polypropylene oxide (monomethyl ether, monoethyl ether,
Monooleyl ether, monolauryl ether, monostearyl ether, monononyl phenyl ether, monooctyl phenyl ether, monolanoline alcohol ether, etc.), and monoesters of polyethylene oxide and polypropylene oxide (the monoester is monoacetate) Mono (meth) acrylate, monooleate, monolaurate, monostearate, monolanoline fatty acid ester, etc.), and polycaprolactone, etc., and monoether and monoester of polyethylene oxide. Is particularly preferred.

Next, (B) a polyfunctional isocyanate having two or more isocyanate groups in the molecule will be described. As such compounds, for example, compounds having two isocyanate groups in a molecule include m-phenylene diisocyanate, p-phenylene diisocyanate,
2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane -4,4'-
Diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, 4-chloroxylylene-1,3-diisocyanate, 2-methylxylylene-1,3-diisocyanate, 4,4′-
Diphenylpropane diisocyanate, 4,4'-diphenylhexafluoropropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-
1,2-diisocyanate, cyclohexylene-1,3
-Diisocyanate, cyclohexylene-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,4-bis (isocyanatomethyl) cyclohexane and 1,3-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate, lysine diisocyanate, etc. Is mentioned. Further, addition products of these bifunctional isocyanate compounds with bifunctional alcohols such as ethylene glycols and bisphenols, and phenols can also be used.

Further, polyfunctional isocyanate compounds can also be used. Examples of such a compound include the above-mentioned bifunctional isocyanate compound as a main raw material and a polyfunctional as an adduct of a trimer (buret or isocyanurate), a polyol such as trimethylolpropane, and a bifunctional isocyanate compound. , Isocyanate compounds having a polymerizable group such as methacryloyloxyethyl isocyanate, and lysine triisocyanate. In particular, xylene diisocyanate and its hydrogenated product, hexamethylene diisocyanate, tolylene diisocyanate and its hydrogenated product are the main raw materials, and in addition to their trimers (buret or isocyanurate), polyfunctional as adducts with trimethylolpropane Preferred is These compounds are described in "Polyurethane Resin Handbook" (edited by Keiji Iwata, published by Nikkan Kogyo Shimbun (1987)).

Among these, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3
-Diisocyanate, trimethylolpropane and xylylene-1,4-diisocyanate or xylylene-
Adducts with 1,3-diisocyanate are preferred, especially xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate, trimethylolpropane with xylylene-1,4-diisocyanate or xylylene-1,3-diisocyanate. Adducts are preferred.

The reaction ratio between the active hydrogen of (A) and the isocyanate group of (B) is 1/100 to 50/100 m
ol ratio, preferably 2/100 to 40/10
0 is particularly preferred. If the reaction ratio is less than 1/100, the effect of improving sensitivity is insufficient, and if it exceeds 50/100, the amount of isocyanate groups decreases, making it difficult to form capsules. The above-mentioned addition reaction between the active hydrogen of (A) and the isocyanate group of (B) is performed, for example, by heating both compounds in an organic solvent having no active hydrogen while stirring (about 50 to 100 ° C.). Or by heating at a relatively low temperature (about 40 to 70 ° C.) while adding a catalyst such as stannous octylate or dibutyltin diacetate. Examples of the organic solvent include, for example, ethyl acetate, chloroform, tetrahydrofuran, methyl ethyl ketone, acetone, acetonitrile, toluene and the like. The adduct of compound (A) and compound (B) may be one type or a mixture of two or more types.

In addition to the adduct of compound (A) and compound (B), a known polyfunctional isocyanate having two or more isocyanate groups can be used in combination as a raw material for the microcapsules. As an example of such a polyfunctional isocyanate, the compounds exemplified as the above-mentioned compound (B) can be used in combination at an appropriate ratio.

These polyfunctional isocyanate compounds are
They may be used alone or in combination of two or more. However, in this case,
The ratio of the compound (A) to the polyfunctional isocyanate used in combination with the adduct of the compound (B) is preferably from 100/0 to 10/90 by weight.

The polymerization of these isocyanate compounds is carried out, for example, by a reaction with a compound having two or more active hydrogen atoms in the molecule. Examples of such compounds include, in addition to water, polyhydric alcohol compounds such as ethylene glycol and glycerin, polyamine compounds such as ethylene diamine and diethylene triamine, and mixtures thereof. Of these, it is particularly preferable to carry out the polymerization using water. This results in the formation of a polyurethane / polyurea wall. In the present invention, a conductive polymer is preferably mixed with the wall material, and polyether is preferable as the conductive polymer. As the polyether that can be used here, (A) the polyether mentioned as a preferable example in the description of the compound having one active hydrogen in the molecule and having a molecular weight of 500 to 20,000 is preferable. . It is preferable to use these polyethers by blending them with a capsule wall material exhibiting material permeability at high energy and medium energy, respectively.

In the present invention, a known method can be used as a method for forming microcapsules containing a coloring material using the polymer constituting the wall material. For example, in order to enclose a compound exhibiting electrochromism in microcapsules, the coloring material compound is dissolved in a hydrophobic solvent (oil phase), and this is dissolved in an aqueous solution (water phase) in which a water-soluble polymer is dissolved. In addition, by emulsifying and dispersing with a homogenizer, etc., the monomer or prepolymer serving as the wall material of the microcapsule is added to either or both of the oil phase side and the water phase side, so that the interface between the oil phase and the water phase is obtained. By causing a polymerization reaction or precipitating a polymer to form a polymer wall, microcapsules containing an electrochromic compound can be obtained.

These methods are described in, for example, "Microcapsules" by Asashi Kondo, Nikkan Kogyo Shimbun (published in 1970),
Tamotsu Kondo et al., "Microcapsule" Sankyo Publishing (197
7 years). When a microcapsule having a urea resin or urethane resin wall is formed by using a polyvalent isocyanate compound as a capsule wall material as in the present invention, specifically, first, an electrochromic compound is dissolved in an organic solvent. Then, a polyvalent isocyanate compound is added thereto, and the organic phase solution is emulsified in a water-soluble polymer aqueous solvent. Thereafter, a method of adding a catalyst for accelerating the polymerization reaction to the aqueous phase or increasing the temperature of the emulsion to polymerize the polyvalent isocyanate compound to form a capsule wall is common.

Hereinafter, a method for producing the color material compound-containing microcapsules will be described in detail. Here, a compound exhibiting electrochromism suitable as a coloring material of the present invention (hereinafter, referred to as
(Referred to as an electrochromic compound as appropriate). First, the electrochromic compound is dissolved or dispersed in a hydrophobic organic solvent serving as a core of the capsule. In this case, the organic solvent may have a boiling point of 100-30.
Organic solvents at 0 ° C. are preferred. In the core solvent, a polyvalent isocyanate is further added as a wall material (oil phase).

On the other hand, as the aqueous phase, an aqueous solution in which a water-soluble polymer such as polyvinyl alcohol, gelatin or the like is dissolved is prepared, and then the oil phase is charged and emulsified and dispersed by means such as a homogenizer. At this time, the water-soluble polymer acts as a stabilizer for emulsification and dispersion. A surfactant may be added to at least one of the oil phase and the aqueous phase in order to perform the emulsification and dispersion more stably.

The amount of the polyvalent isocyanate used is determined so that the microcapsules have an average particle size of 0.3 to 12 μm and a wall thickness of 0.01 to 0.3 μm. The dispersed particle diameter is generally about 0.2 to 10 μm. In the emulsified dispersion, the polyurea isocyanate undergoes a polymerization reaction at the interface between the oil phase and the aqueous phase to form a polyurea wall.

If a polyol is added to the aqueous phase, the polyvalent isocyanate can react with the polyol to form a polyurethane wall. It is preferable to keep the reaction temperature high or to add an appropriate polymerization catalyst in order to increase the reaction rate. Detailed information on polyisocyanates, polyols, reaction catalysts, and polyamines for forming a part of the wall material is available in a book (Keiji Iwata, Polyurethane Handbook, Nikkan Kogyo Shimbun (198)
7)).

Further, a polyol or a polyamine may be added to a hydrophobic solvent serving as a core or a water-soluble polymer solution serving as a dispersion medium, and used as one of the raw materials for the microcapsule wall. Specific examples of these polyols or polyamines include propylene glycol, glycerin, trimethylolpropane, triethanolamine, sorbitol, hexamethylenediamine, and the like. When a polyol is added, a polyurethane wall is formed.

As the hydrophobic organic solvent for dissolving the above-mentioned electrochromic compound to form the core of the microcapsule, an organic solvent having a boiling point of 100 to 300 ° C. is preferable. Specifically, alkylnaphthalene, alkyldiphenylethane, Alkyl diphenylmethane, alkyl biphenyl, alkyl terphenyl, chlorinated paraffin, phosphates, maleates, adipates, phthalates, benzoates,
Examples thereof include carbonates, ethers, sulfates, and sulfonates. From the viewpoint of the responsiveness of color development and discoloration, the solvent used is preferably one having high electric conductivity. These may be used as a mixture of two or more.

When the electrochromic compound to be encapsulated has poor solubility in these solvents, a low-boiling solvent having high solubility in the compound to be used can be used in combination. Specific examples include ethyl acetate, butyl acetate, methylene chloride, tetrahydrofuran, acetonitrile, acetone and the like. For this reason, it is preferable that the electrochromic compound has an appropriate solubility in these high-boiling hydrophobic organic solvents and low-boiling auxiliary solvents, and specifically has a solubility of 5% or more in the solvent. Is preferred. The solubility in water is preferably 1% or less.

The water-soluble polymer used in the aqueous solution of the water-soluble polymer for dispersing the oil phase of the capsule thus prepared is preferably a water-soluble polymer having a solubility in water of 5% or more at the temperature to be emulsified. Specific examples thereof include polyvinyl alcohol and modified products thereof, polyacrylamide and derivatives thereof, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, isobutylene- Maleic anhydride copolymer, polyvinylpyrrolidone, ethylene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer,
Examples include carboxymethylcellulose, methylcellulose, casein, gelatin, starch derivatives, gum arabic, sodium alginate and the like.

It is preferable that these water-soluble polymers have no or low reactivity with the isocyanate compound. For example, those having a reactive amino group in the molecular chain such as gelatin are modified beforehand. It is necessary to eliminate reactivity. In addition, when a surfactant is added, the amount of the surfactant to be added is 0.1 to the weight of the oil phase.
It is preferably from 1% to 5%, particularly preferably from 0.5% to 2%.

The emulsification is performed by using a homogenizer, a Menton-Gawley, an ultrasonic disperser, a dissolver, a Keddy mill, or the like.
A known emulsifying apparatus can be used. After the emulsification, the emulsified product is 30 to 70 to promote the capsule wall forming reaction.
Warming to ° C is performed. During the reaction, in order to prevent the capsules from agglomerating, it is necessary to reduce the collision probability between the capsules by adding water or to perform sufficient stirring.

During the reaction, a dispersion for preventing aggregation may be added again. Generation of carbon dioxide gas is observed with the progress of the polymerization reaction, and the end thereof can be regarded as an approximate end point of the capsule wall forming reaction. Usually, by reacting for several hours, the desired microcapsules containing the electrochromic compound can be obtained.

The present invention relates to a wall material of a microcapsule containing an electrochromic compound by selecting a polymer having a material permeability at each of high energy, medium energy and low energy and having different electric conductivity according to the purpose. Use as It is preferable to select a solvent having excellent conductivity from the viewpoint of the responsiveness of color development and discoloration reaction as the solvent encapsulated in the microcapsules together with the electrochromic material.

In the present invention, as the capsule wall material,
Due to the use of a material whose electrical conductivity changes by stimulation, a material that changes hue by electrical stimulation is used as a color-forming or discoloring material. It is preferable to use a chromic material (a material that develops and discolors) or a material that fixes after discoloration, discoloration, or decoloration of a predetermined portion. Here, an electrochromic compound which is a coloring material suitably used in the present invention will be described. For the electrochromic compound, see “Electrochromic Display” (Sangyo Tosho, published in 1991).
In more detail. As the electrochromic compound that can be suitably used in the present invention, Examples 40 to 40 of the book
Organic materials described on page 59 can be mentioned, and these organic materials are suitable for reversible recording / display materials.

When the recording / display material of the present invention performs irreversible recording / display, the electrochromic compound used may be a leuco-based compound which develops a color by an oxidation-reduction reaction, or a decolorization by an oxidation-reduction reaction. Coloring agents. In these materials, after discoloring or decoloring, a fixing step is performed to stabilize the formed image. Examples of the leuco-based compound which develops a color by the oxidation-reduction reaction are described in "Basics of Photographic Engineering-Non-Silver Photography" (Corona Co., 1982), Nos. 77-8.
Compounds used for the free radical photography described on page 9 and compounds used for the photo-redox reaction described on pages 118 to 133 are exemplified.

In the recording / display material of the present invention, electrochromic compounds having different oxidation potentials for achieving color display will be described. In the present invention, the oxidation potential refers to a value measured in acetonitrile using tetrabutylammonium perchlorate as an electrolyte using a platinum rotating electrode. A preferred combination of the potentials at which the electrochromic compounds E ₁ , E ₂ , and E _{3 which} are the coloring materials develop a color is in the following range. E ₁ ≦ 600 mV to 750 mV 1000 mV to 1200 mV <E ₃ E ₂ is located between E ₁ and E ₃ , and the respective relations are E ₁ <
E ₂ <E ₃ . The difference between the respective oxidation potentials, that is, E
100 to 300 m between the oxidation potentials of ₁ and E ₂ , E ₂ and E ₃
Preferably, there is a difference in V, and the difference is 200
It is preferable that the voltage be in the range of 300 mV from the viewpoint that the control of the coloring condition is easy.

The following are examples of electrochromic compounds that can be suitably used in the present invention, but the present invention is not limited thereto. Electrochromic compound E
The _1, include the following E ₁ -1~E ₁ -4.

[0079]

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[0080] As electrochromic compound E ₂ include the following E ₂ -1~E ₂ -3.

[0081]

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[0082] As electrochromic compound E ₃ include the following E ₃ -1~E ₃ -3.

[0083]

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The electrochromic compound may be used alone, and as long as the oxidation potential is within a preferable range,
Two or more selected from the viewpoints of compatibility, hue, and reactivity may be used in combination. The recording / display layer of the recording / display material according to the present invention preferably contains the electrochromic compound in an amount of 0.1 to 1.0 mmol / m ^{2, and} preferably 0.15 to 0, depending on the intended use. 0.5 mmol / m ² is more preferred.

The applied voltage of the microcapsules whose electrical conductivity changes due to the stimulation containing the electrochromic compound can be determined by measuring in advance. Therefore, when using a plurality of types of microcapsules, in relation to the oxidation potential of the electrochromic compound and the microcapsule wall material described above,
By selecting the combination of electrochromic compound and wall material of each color while considering the applied voltage that can generate color, combining color materials with excellent hue and color reproducibility, realizing free color tone coloration Can be.

The recording / display material of the present invention is prepared by preparing a coating liquid containing a microcapsule containing a binder and other additives, and a microcapsule containing an electrochromic compound and having a change in electric conductivity due to stimulation. Coating and drying by a coating method such as bar coating, blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, curtain coating, etc. on a support such as a thermosensitive material having a solid content of 5 to 50 g / m ² . A recording layer is provided. The binder used in the present invention is not particularly limited, polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose,
Conventionally known binders such as carboxymethylcellulose, gelatin, and styrene-acrylic acid copolymer can be used. For details, see JP-A-2-141279.
No., etc. In addition, various organic or inorganic pigments, various stabilizers, antioxidants, and the like can be added as necessary.

As the support used in the present invention, a conventionally known support can be used. Specifically, neutral paper, acidic paper, recycled paper, polyolefin resin laminated paper, synthetic paper, polyester film, cellulose derivative film such as cellulose triacetate film, polystyrene film, polyolefin film such as polypropylene film and polyethylene film, etc. These can be used alone or bonded together. The support has a thickness of 20 to 200 μm. It is also possible to provide an intermediate layer between the support and the recording / display layer. This is described in JP-A-61-54.
980 and the like.

In the recording / display material of the present invention, three different color-forming layers containing microcapsules having the respective color-forming conditions can be provided as shown in FIG.
The microcapsules containing each color material independently develop color under predetermined conditions, and since there is no concern that they interact with each other, a uniform recording / display layer contains a plurality of types of color material-containing microcapsules, It is also possible to use a single recording / display layer as shown in FIG.

In the recording / display material of the present invention, a protective layer may be provided on the uppermost layer. This protective layer is composed of a water-soluble polymer compound, a pigment and the like. It is preferable that a compound having an ultraviolet transmittance adjusting function is contained in the protective layer from the viewpoint of achieving both light resistance and light fixing property. The recording material containing the compound having the function of adjusting the ultraviolet transmittance is described in detail in JP-A-7-276808.

It is to be noted that the recording / display material of the present invention is preferably provided with a conductive layer when performing reversible display, for example. A preferred embodiment of the recording / display material having a conductive layer will be described with reference to FIG. FIG. 3 is a schematic sectional view showing one embodiment of the constitution of the recording / display material of the present invention. The recording / display material 10 includes a conductive layer 14, a recording / display layer 16Y, a recording / display layer 16M, a recording / display layer 16C, and a transparent conductive layer 18 sequentially provided on a support 12. . Each of the recording / display layers 16Y to 16C has a configuration in which microcapsules containing a coloring material in a binder are dispersed, and a transparent conductive layer 18 on the recording side and a conductive layer 14 formed on a support are provided. Recording / display layer 16Y between
The thickness of ~ 16C can be controlled by adjusting the amount of application.
Here, a known ITO electrode or the like can be used as the conductive layer. Further, when an electrode is provided on the hard side for performing recording and display, recording and display can be performed by directly providing the recording and display layers 16Y to 16C as described above on such a device. Therefore, the conductive layer 18 is not an essential constituent layer of the recording / display material of the present invention.

In recording, when a thermal stimulus of a predetermined intensity is applied imagewise from the transparent conductive layer 18 side by a thermal head, a heat roller, an infrared laser, or the like, the microcapsule wall of the portion provided with the thermal stimulus is applied. Becomes electrically conductive. Therefore, when a voltage is applied under a condition that gives an oxidation potential at which the coloring material contained between the transparent conductive layer 18 and the conductive layer 14 on the support develops a color, the colorant is present in the capsule that has developed electrical conductivity, Only the electrochromic compound that develops a color at a predetermined oxidation potential develops a color, and an image having a desired hue is formed. After that, when the thermal stimulation is completed, the electrical conductivity of the capsule wall material is lost, the electrochromic compound that has developed color is stably held in the microcapsules, and the stability of the formed image is good. By repeating this recording process in accordance with the conditions of a plurality of types of color materials and microcapsules, a multicolor image can be formed. As shown in FIG. 3, the recording / display layer 16Y containing a coloring material that develops three colors of yellow, magenta, and cyan.
To 16C, and the above-described steps are repeated for each hue to form a full-color image. The details of the microcapsules made of a wall material whose electrical conductivity changes due to color development, discoloration components, and stimulation used herein are as described above. According to the present invention, the coloring material is always protected in the capsule except at the time when the stimulus for changing the electrical conductivity of the capsule wall material is applied, so that the electrochromic compound is relatively stable. It also has the advantage that it can be suitably used as a coloring material, even if it is low.

Further, the recording / display material of the present invention can be used as a reversible display material when the hue change of the coloring material used, or the coloring and decoloring are reversible. Taking color development and decolorization as examples, after forming an image with the electrochromic compound as described above, to erase the image, the entire recording / display material is heated to remove all the microcapsule wall materials. Electric conductivity, the voltage in the direction in which the electrochromic compound contained in the capsule is decolorized (for example, when an oxidation potential is applied to color development,
(Reduction potential) may be applied. By applying this voltage,
The color material in the capsule that has developed color is erased, and the other color materials in the capsule do not change, so that the formed image can be erased. The formation and erasing of the image can be arbitrarily repeated any number of times by only applying the thermal stimulus and controlling the voltage until the end of the life of the electrochromic compound.

[0093]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
In addition, "part" in an Example shows all weight parts.

(Example 1) [Preparation of coating liquid for recording / display layer] (1) Preparation of low energy high potential coloring microcapsule liquid A. Electrochromic compound, dissolve the exemplified compound (E ₃ -1) 4.2 parts 16.0 parts of ethyl acetate, further, propylene carbonate, 3.0 parts of isopropyl biphenyl 7.0 parts a high boiling solvent Add,
Heat to mix evenly.

To the above mixture, as a capsule wall material, xylylene diisocyanate / trimethylolpropane adduct (Takenate D110N, 75% by weight ethyl acetate solution,
4.5 parts by Takeda Pharmaceutical Co., Ltd. and Japanese Patent Application No. 5-233536
To 4.5 parts of a 30% by weight ethyl acetate solution of xylylene diisocyanate / bisphenol A adduct synthesized according to the method described in JP-A-2000-205, 4.5 parts of the isocyanate compound (1) described in Synthesis Example 1 was added, and the mixture was uniformly mixed. Stirred.

Separately, 77 parts of a 6% by weight gelatin aqueous solution to which 0.96 parts of ScrapA G-8 (manufactured by Nippon Seika Co., Ltd.) was added was prepared, and a mixed solution (solution) of the electrochromic compound was added. And emulsified and dispersed with a homogenizer. After 20 parts of water was added to the obtained emulsion to homogenize it, an encapsulation reaction was carried out for 3 hours while stirring at 40 ° C. to obtain a capsule liquid A of an electrochromic compound. The average particle size of the capsule was 0.8 μm.

[0097] (2) as an adjusting electrochromic compound of the medium energy in potential color microcapsule liquid B (E ₂ -2) 3.1
Parts, 2.8 parts of dibutyl sulfate, 2,2-dimethoxy-1,
2-diphenylethan-1-one (Irgacure 65
0.56 parts of ethyl acetate 1
Dissolved in 0.0 parts. Further, isopropyl biphenyl5.
5 parts and 2.9 parts of propylene carbonate were added, and the mixture was heated and uniformly mixed. To the above mixture, 7.6 parts of xylylene diisocyanate / trimethylolpropane adduct (Takenate D110N, 75% by weight ethyl acetate solution, manufactured by Takeda Pharmaceutical Co., Ltd.) was added as a capsule wall material, and the mixture was stirred uniformly. Separately, 6% by weight gelatin (MGP) to which 2.0 parts of a 10% aqueous solution of sodium dodecyl sulfonate was added.
-9066, manufactured by Nippi Gelatin Industry Co., Ltd.) Aqueous solution 64
A mixture was prepared, and a mixture (solution) of the electrochromic compound was added, followed by emulsification and dispersion with a homogenizer.
After adding 20 parts of water to the obtained emulsion and homogenizing it,
The mixture was allowed to react for 30 minutes while stirring, and then the temperature was raised to 60 ° C., and the encapsulation reaction was performed for 3 hours to obtain a capsule liquid B of an electrochromic compound. The average particle size of the capsule was 0.64 μm.

(3) Preparation of high-energy low-potential coloring microcapsule solution C As an electrochromic compound, (E _1-3 ) 3.2
Was dissolved in 15.0 parts of ethyl acetate, 3.0 parts of propylene carbonate and 6.8 parts of isopropyl biphenyl were added, and the mixture was heated and uniformly mixed. To the above mixture, 44.4 parts of the following compound (1) as a capsule wall material and 3.3 parts of Takenate D110N (manufactured by Takeda Pharmaceutical Co., Ltd.), which is an aliphatic isocyanate, were added and uniformly stirred. Next, 2.0 parts of a 10% aqueous solution of sodium dodecylbenzenesulfonate, 6% of an 8% by weight aqueous solution of phthalated gelatin
A mixture of 0 part and 16.8 parts of water was prepared, and a mixture (solution) of the electrochromic compound was added, and the mixture was emulsified and dispersed at 5,000 rpm for 10 minutes at 40 ° C. using a homogenizer. After adding 20 parts of water and 0.25 parts of diethylenetriamine to the obtained emulsion and homogenizing the mixture, the mixture is subjected to an encapsulation reaction with stirring at 40 ° C. for 1 hour. The mixture was heated and subjected to an encapsulation reaction for 3 hours to obtain a capsule solution C of an electrochromic compound. The average particle size of the capsule was 2.6 μm.

[0099]

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[Preparation of Coating Solution for Intermediate Layer] 10 g of 24% by weight aqueous solution of gelatin (# 750, manufactured by Nitta Gelatin Co., Ltd.)
2.4 hollow capsule made of acrylic-styrene resin (Ropek OP-62, manufactured by Rohm and Haas)
g was added and mixed uniformly to obtain an intermediate layer coating solution.

[Preparation of Coating Solution for Protective Layer] 100 parts of 6% aqueous solution of itaconic acid-modified polyvinyl alcohol (KL-318; trade name, manufactured by Kuraray Co., Ltd.) and epoxy-modified polyamide (FL-71; trade name, Toho Chemical Co., Ltd.) 30%
And 10 parts of a dispersion liquid of
15 parts of a 0% dispersion (Hydrin Z; trade name, manufactured by Chukyo Yushi Co., Ltd.) were uniformly mixed to obtain a protective layer coating liquid.

[Preparation of Coating Solution for Recording / Display Layer] 10 parts of water and 7.5 parts of a 15% aqueous solution of lime-processed gelatin were uniformly mixed with 3.5 parts of each of the microcapsule solutions A, B, and C. Recording / display layer coating solutions A, B, and C were obtained.

[Preparation of Recording / Display Material] A 0.1 mm thick paper was laid on a photographic paper support obtained by laminating polyethylene on high quality paper.
A recording / display layer coating solution C containing a microcapsule solution C, an intermediate layer solution, and a microcapsule including a microcapsule solution C in order from a support side on a slide by using a slide type hopper type bead applicator on a layer provided with a 5 μm ITO conductive layer. A multi-layer coating is performed to form a recording / display layer coating liquid B containing the liquid B, an intermediate layer liquid, a recording / display layer coating liquid A containing the microcapsule liquid A, and a protective layer liquid, followed by drying and multi-color recording. Display material was obtained. The coating amount of the recording / display layer was such that the layer containing the microcapsule solution A contained 0.3 mmol / mol of the electrochromic compound.
a layer containing a microcapsule solution B and C as m ² applied was determined as electrochromic compound is ² coated 0.25 mmol / m. Each intermediate layer had a solid content of 1.2 g / m ² , and the protective layer had a solid content of 2.0 g / m ² .
g / m ² .

[Performance test of recording / display material]
The recording characteristics of the recording / display material were evaluated. (1) Image formation An ITO electrode is arranged on the recording / display material and +1.
Apply a voltage of 5V to the thermal head
50mJ / mm^TwoGave the energy. Heat energy
The part to which was applied colored yellow. Next, + 1.0V
100mJ / m by thermal head while applying voltage
m^TwoGave the energy. The thermal energy application section is
It developed a color of zeta. Finally, apply a voltage of + 0.7V
150mJ / mm by thermal head ^TwoEnel of
Gee gave. Heat energy application part develops cyan color
did. In this way, two types of energy are combined and printed three times
To add yellow, magenta, and cyan.
It can be obtained freely. The recorded image is
The image was sharp and high quality.

(2) Image Erasing The front surface was heated to 180 ° C. by a heat roller while applying a voltage of −1.0 V to the recording / display material on which the image was formed.
As a result, the formed image was erased and no color remained. It returned to the same state as before recording by visual observation. (3) Performance test of image formation / disappearance The results of the performance test of image formation / disappearance are summarized. The optical density of the image portion and the non-image portion was determined by measuring the optical reflection density with a Macbeth RD918 densitometer. The results are shown in Table 2 below.

[0106]

[Table 2]

As is apparent from Table 2, according to the recording / display material of the present invention, images of desired hues could be obtained not only in each color of yellow, magenta and cyan, but also in intermediate colors and black. .

Example 2 As a support, a paper having a thickness of 0.1 mm was formed on a photographic paper support obtained by laminating high quality paper with polyethylene.
A multi-layered recording / display material was obtained by multi-layer coating in the same manner as in Example 1 except that a polyimide film having a matrix electrode was used instead of the one provided with the 15 μm ITO conductive layer. [Performance test of recording / display material] (1) Image formation A matrix electrode was provided on the recording / display material. A voltage of +1.5 V as a matrix potential was applied while the front surface was heated to 100 ° C. on a hot plate. The portion where the voltage was applied developed yellow. Next, a voltage of +1.0 V was applied to the matrix electrode while heating the entire surface to 150 ° C. The voltage application section developed a magenta color. Finally one
+0.7 with matrix electrode while heating to 80 ° C over the entire surface
A voltage of V was applied. The voltage application part developed cyan.
By applying two types of energy three times in the same manner as in the first embodiment, each color of yellow, magenta, and cyan can be obtained freely. The recorded image was a high-quality image with high sharpness. (2) Image Erasing While a recording / display material on which an image was formed was heated at 180 ° C. over its entire surface, a voltage of −1.0 V was applied to all the matrix electrodes. As a result, the formed image was erased and returned to the state before the image formation. (3) Performance Test of Image Forming / Erasing The optical density of the image portion and the non-image portion is different from Example 1 and is obtained by measuring the transmission density. The results are shown in Table 3 below.

[0109]

[Table 3]

As is clear from Table 3, even when the recording / display layer is provided directly on the matrix electrode without using the ITO film, the respective colors of yellow, magenta and cyan can be obtained by the recording / display material of the present invention. , An image of a desired hue up to a neutral color or black was obtained.

(Example 3) The low energy high potential coloring microcapsule solution A, the medium energy medium potential coloring microcapsule solution B, and the high energy low potential coloring microcapsule solution C obtained in Example 1 were each 3.0 parts and water. 10
And 7.5 parts of a 15% aqueous solution of lime-processed gelatin were uniformly mixed to obtain a recording / display material coating liquid D.

FIG. 4 is a schematic sectional view showing the structure of the recording / display material 20 of the third embodiment. 0.15 μm thick on photographic paper support 12 with high quality paper laminated with polyethylene
m of the recording / display layer coating liquid D in order from the support side on a slide by using a slide type hopper type bead coating device on the one provided with the ITO conductive layer 14 of m.
The multi-layer recording / display material 20 having the recording / display layer 22 and the protective layer 24 as shown in FIG. Microcapsules Y, M, and C containing three kinds of electrochromic compounds are uniformly dispersed in the recording / display layer 22. The coating amount of the recording / display layer coating solution D was determined so that each of the three kinds of electrochromic compounds was applied at 0.22 mmol / m ² . The protective layer has a solid content of 2.0 g / m2.
² was applied.

This recording / display layer has a single-layered multicolor recording / display structure.
As for the display material, a performance test of the recording / display material was performed in the same manner as in Example 1.
Similarly to the above, it is possible to freely obtain each color of yellow, magenta, and cyan by applying two types of energy three times, and the recorded image has a high sharpness and a high quality image. there were. Further, the image could be erased in the same manner.

The results of the above-described image formation / disappearance performance test were summarized in the same manner as in Example 1. The optical density of the image portion and the non-image portion was determined by measuring the optical reflection density with a Macbeth RD918 densitometer. The results are shown in Table 4 below.

[0115]

[Table 4]

As is clear from Table 4, according to the present invention,
In a recording / display material comprising a single-layer recording / display layer, similarly to the multilayer structure, an image of a desired hue can be obtained, from yellow, magenta, and cyan to intermediate colors and black. Was.

[0117]

As described above, according to the present invention, it is possible to use a plurality of types of electrochromic compounds as coloring materials without providing cells in the display material. It is possible to provide a recording / display material capable of writing (recording) and reversible display by electrical stimulation and forming a high-quality color image with high sharpness.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a coloring region of a coloring material of a recording / display material of the present invention.

FIG. 2 is a schematic cross-sectional view showing one embodiment of a configuration of a multilayer recording / display layer having different hues.

FIG. 3 is a schematic cross-sectional view showing one embodiment of the configuration of the recording / display material of the present invention.

FIG. 4 is a schematic cross-sectional view illustrating a configuration of a recording / display material of Example 3.

[Explanation of symbols]

 Reference Signs List 10, 20 recording / display material 12 support 14 conductive layer 16Y, 16M, 16C recording / display layer 18 transparent conductive layer 22 recording / display layer (including a plurality of color-forming components) 24 protective layer

 ──────────────────────────────────────────────────の Continued on the front page F-term (reference) 2H086 AA11 AA46 AA48 2K001 AA02 AA17 CA02 CA04 CA08 CA22 DA04 EA09 EA12 5C094 AA05 AA06 AA08 AA52 AA54 BA09 BA12 BA54 CA18 CA24 CA25 DA13 EA04 EA05 EB02 FA02 FB02 GA02 FB02

Claims (5)

[Claims] Claims: 1. A recording / display device comprising a recording / display layer containing a microcapsule encapsulating a color-forming or discoloring component on a support.
A display material, wherein the recording / display layer includes a color material that changes color and changes color in response to electrical stimuli of different intensities, and a wall material whose electrical conductivity changes by stimuli of different intensities. A recording / display material comprising at least two kinds of microcapsules. 2. The recording / display material according to claim 1, wherein the coloring and discoloring components are compounds exhibiting electrochromism that develops and discolors by electric stimuli of different intensities. 3. The recording / display material according to claim 1, wherein the microcapsules containing the at least two kinds of coloring and discoloring components are present in the same recording / display layer. 4. The microcapsules which include: (1) a microcapsule which contains a coloring and discoloring component which develops a color due to a high potential, and whose electric conductivity changes at a low temperature as a wall material;
(2) Includes coloring and discoloration components that develop color due to medium potential,
There are three types of microcapsules, the wall material of which changes electrical conductivity at medium temperature, and (3) the microcapsules of which color develops due to low potential and discoloration components are included and the electrical conductivity changes at high temperature as wall material. 4. A full-color display is enabled by containing.
The recording / display material according to any one of the above. 5. A recording / display material in which a conductive layer, a recording / display layer, and a transparent conductive layer are sequentially provided on a support, wherein the recording / display layer is dispersed in a binder. A recording / display material comprising at least two types of microcapsules containing a wall material which contains different coloring and discoloring components and whose electrical conductivity changes by stimuli of different intensities.