JP2554913B2 - Multicolor recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a multicolor recording material, and more particularly to a heat-sensitive, pressure-sensitive and / or photosensitive recording material having a recording layer in multiple layers so that multicolor recording is possible.

<< Prior Art >> The silver salt photography method has been widely put into practical use as the most general method for obtaining a multicolor image from the viewpoint of high sensitivity, high image quality, and rich gradation reproducibility. However, the present salt photography method has a drawback in that the process is complicated because after the image is exposed, it is processed with a developing solution, and then the remaining silver halide is converted into a water-soluble silver complex salt or a light-stable silver salt. have.

As a method for improving these drawbacks, Japanese Patent Laid-Open No. 59-4876.
No. 4, etc., describes a dry silver salt photographic light-sensitive material, see British Patent No. 249.
No. 530, U.S. Patent No. 2,020,775, No. 2,004,625, No. 2,217,544, No. 2,255,463, No. 2,699,394 and the like, dye diffusion transfer method photographic light-sensitive material described, U.S. Patent No. 2,
No. 844,584 describes a silver dye bleaching method photographic light-sensitive material.

On the other hand, as a recording material that does not use silver salt, recording methods such as an electrophotographic method, a thermal transfer method, and an inkjet method, which have a mechanism for multicolor recording in the apparatus, are used. There are drawbacks such as lack of property and time-consuming replacement of consumables.

As a non-silver salt recording material having a mechanism of a multi-color recording material, a recording material combining a color forming method such as pressure-sensitive, heat-sensitive and photosensitive is disclosed in Japanese Patent Application Nos. 61-80787 and 61-2.
82789, 61-303504, 62-3069, 62-3070
No. 62-22234, No. 62-52423, No. 62-75409, and the like.

Further, as the one using the thermal recording system, for example,
As one of the conventional methods, Japanese Patent Publication Nos. 51-19989 and 52-11231.
No. 54-88135, No. 55-133991, No. 55-13399.
As described in No. 2 and the like, there is a method in which a plurality of color-forming units are simply sequentially added as the applied heat energy increases and the colors are mixed to change the hue while becoming turbid. Other methods include, for example, Japanese Examined Patent Publications Nos. 50-17868, 51-5791, and 57-14318.
No. 57-14319 and JP-A No. 55-161688, a decoloring agent simultaneously acts when a color-forming unit having a higher thermal response temperature develops color, thereby decoloring the color-forming unit that develops at a low temperature. There is one that incorporates the erasing mechanism.

<< Problems to be Solved by the Invention >> As described above, in a recording material in which a recording layer is provided in multiple layers and has a mechanism of a multicolor recording material, it is important to prevent inconvenient interlayer movement of the material of each layer. .

For example, in the case of a light- and heat-sensitive recording material in which the first layer is a combination of a basic dye and a developer and the second layer is a combination of a diazo compound and a coupler, the developer contained in the first layer is It acts on the second layer to promote the coupling reaction of the second layer, which causes a problem that fog is generated on the second layer over time, and a diazo compound and a base generally contained in the coupler system as a coupling accelerator. First of all
There is a problem that the color development reaction of the layer is inhibited and the color density of the first layer during color development is reduced.

Therefore, a first object of the present invention is to provide a recording material capable of obtaining a multicolor image having high color density and less fog.

A second object of the present invention is to provide a material between the color-developing layers in a multicolor recording material in which at least two recording layers are provided in multiple layers, each of which has a different hue due to a color-developing reaction on one surface of the support. It is to provide an intermediate layer suitable for preventing interlayer movement.

<< Means for Solving the Problems >> The above-mentioned objects of the present invention are multi-colored in which one surface of a support is provided with at least two color-developing layers, which are colored in different hues by a color-developing reaction, in multiple layers. In the recording material, it is achieved by a multicolor recording material characterized in that an intermediate layer in which a water-soluble polymanion polymer is gelled with a polyvalent cation is provided between each color forming layer.

The coloring layer according to the present invention is not particularly limited, but (1) a coloring layer formed by combining a diazo compound and a coupler, (2) a coloring layer formed by combining a basic dye precursor and a developer, (3) A coloring layer formed by combining an organic reducing agent, a chelating agent, a sulfur compound, etc. and an organic acid metal salt,
(4) Preferable is a color-forming layer formed by combining an organic base and a color-forming substance capable of forming a color by reacting with an organic base.

The diazo compound in the present invention mainly means an aromatic diazo compound, specifically, an aromatic diazonium salt,
It means a compound such as a diazosulfonate compound and a diazoamino compound. Hereinafter, as a representative example, a diazonium salt will be mainly described as an example.

The diazonium salt is a compound represented by the general formula ArN ₂ ⁺ X ⁻ (wherein Ar represents a substituted or unsubstituted aromatic moiety, N ₂ ⁺ represents a diazonium group, and X ⁻ represents an acid. Represents an anion).

Examples of the diazonium compound preferably used in the present invention include 4-diazo-1-dimethylaminobenzene,
4-diazo-1-diethylaminobenzene, 4-diazo-1-dipropylaminobenzene, 4-diazo-1-methylbenzenediaminobenzene, 4-diazo-1-dibenzylaminobenzene, 4-diazo-1-ethyl Hydroxyethylaminobenzene, 4-diazo-1-diethylamino-3-methoxybenzene, 4-diazo-1-dimethylamino-2-methylbenzene, 4-diazo-1-
Benzoylamino-2,5-diethoxybenzene, 4-diazo-1-morpholinobenzene, 4-diazo-1-morpholino-2,5-diethoxybenzene, 4-diazo-1-
Morpholino-2,5-dibutoxybenzene, 4-diazo-
1-anilinobenzene, 4-diazo-1-toluylmercapto-2,5-diethoxybenzene, 4-diazo-1,4-
Methoxybenzoylamino-2,5-diethoxybenzene, 1-diazo-4- (N, N-dioctylcarbamoyl) benzene, 1-diazo-2-octadecyloxybenzene, 1-diazo-4- (4-tert-octyl Phenoxy) benzene, 1-diazo-4- (2,4-di-tert-
Aminophenoxy) benzene, 1-diazo-2- (4-
tert-octylphenoxy) benzene, 1-diazo-5
-Chloro-2- (4-tert-octylphenoxy) benzene, 1-diazo-2,5-bis-octadecyloxybenzene, 1-diazo-2,4-bis-octadecyloxybenzene, 1-diazo-4- ( N-octyl theuroyl amino) benzene etc. can be mentioned. The aromatic diazonium compounds represented by the above-mentioned examples can widely change their photolytic wavelengths by arbitrarily changing their substituents.

Specific examples of the acid anion include C _n F _{2n + 1} COO ⁻ (where n is 3
Represent _{~9), C m F 2m +} 1 SO 3 - (m represents _{2~8), (ClF 2L + 1} SO 2) 2 CH - (l represents 1 to 18), BF ₄ ^- and PF ₆ ^- are listed.

Particularly as an acid anion, a perfluoroalkyl group,
Alternatively, those containing a perfluoroalkenyl group, or PF ₆ ⁻ are preferable because the increase in fog during raw storage is small.

Specific examples of the diazo compound (diazonium salt) include:
For example, the following examples can be given.

The diazosulfonate compound that can be used in the present invention has the general formula Is a compound represented by. In the formula, R ₁ is an alkali metal or ammonium compound, R ₂ , R ₃ , R ₅ and R ₆ are hydrogen, halogen, an alkyl group or an alkoxyl group, and R ₄ is hydrogen,
It is a halogen, an alkyl group, an amino group, a benzoylamide group, a morpholino group, a trimercapto group, or a pyrrolidino group.

Many such diazosulfonates are known and are obtained by treating each diazonium salt with a sulfite.

Among these compounds, preferred compounds include 2-
Methoxy, 2-phenoxy, 2-methoxy-4-phenoxy, 2,4-dimethoxy, 2-methyl-4-methoxy,
2,4-dimethyl, 2,4,6-trimethyl, 4-phenyl, 4
-Benzeneoxysulfonate having a substituent such as phenoxy and 4-acedamide, or 4- (N-ethyl-N-benzylamino), 4- (N,
N-dimethylamino), 4- (N, N-diethylamino)-
3-chloro, 4-pyridinino-3-chloro, 4-morpholino-2-methoxy, 4- (4'-methoxybenzylbenzoylamino) -2,5-dibutoxy, 4- (4'-mercapto) -2,5 -A benzenesulfonate having a substituent such as dimethoxy. When using these diazosulfonate compounds, it is desirable to perform light irradiation for activating the diazosulfonate before printing.

Further, as another diazo compound which can be used in the present invention, a diazoamino compound can be mentioned. The diazoamino compound is a compound obtained by coupling a diazonium salt with dicyandiamide, sarcosine, methyltaurine, N-ethylanthranic acid-5-sulphonic acid, monoethanolamine, diethanolamine, guanidine and the like.

The developer for the diazo compound used in the present invention is
It is a coupling component that forms a dye by coupling with a diazo compound (diazonium salt).

Specific examples thereof include 2-hydroxy-3.
In addition to naphthoic acid anilide, those described in Japanese Patent Application No. 60-287485 including resorcin can be mentioned.

Furthermore, an image of any color tone can be obtained by using two or more of these coupling components in combination. Since the coupling reaction between these diazo compound and the coupling component easily occurs in a basic atmosphere, a basic substance may be added in the layer.

As the basic substance, a poorly water-soluble or water-insoluble basic substance or a substance which generates an alkali upon heating is used. Examples thereof are inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and their derivatives, thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidazolines, triazoles. , Morpholines,
Examples thereof include nitrogen-containing compounds such as piperidines, amidines, formazines and pyridines. Specific examples of these are described in, for example, Japanese Patent Application No. 60-132990. Two or more basic substances may be used in combination.

The hue in this coloring system is mainly determined by the diazo dye produced by the reaction of the diazo compound and the coupling component. Therefore, as is well known, the coloring hue can be easily changed by changing the chemical structure of the diazo compound or the chemical structure of the coupling component, and almost any coloring hue can be obtained depending on the combination. be able to.
For this reason, one layer may contain various diazo compounds and one type of coupling component or another additive may be incorporated in the same layer. At this time, each unit coloring group has a different diazo compound. And other common coupling components and other additives. Further, there is a combination in which different coupling components are contained in some layers and the same diazo or other additive is incorporated in each layer. At this time, each unit color forming group is composed of a different coupling component, a diazo compound and an additive which are common to the other components. In any case, each unit coloring group is composed of one or more diazo compounds and one or more coupling components and other additives which are combined so as to have different coloring hues.

The coupling component is 0 with respect to 1 part by weight of the diazo compound.
It is preferable to use 1 to 10 parts by weight and the basic substance in an amount of 0.1 to 20 parts by weight.

The basic dye precursor referred to in the present invention has a property of developing a color by donating electrons or by receiving a proton such as an acid, and is not particularly limited, but is usually substantially colorless. A compound having a partial skeleton such as a lactone, a lactam, a sultone, a spiropyran, an ester, an amide, etc., and the partial skeleton is ring-opened or cleaved upon contact with a color developer is used. Specifically, crystal violet lactone, benzoyl leuco methylene blue, malachite green lactone, rhodamine B lactam, 1,
2,3-trimethyl-6'-ethyl-8'-butoxyindolinobenzospiropyran and the like.

As the color developer for these coloring materials, an acidic substance such as a phenol compound, an organic acid or a metal salt thereof, an oxybenzoic acid ester, and activated clay is used.

Specific examples of these color developing agents include, for example, Japanese Patent Application No. 60-132990.
No.

0.3 to 80 color developer for 1 part by weight of basic dye precursor
It is preferable to use parts by weight.

Organic reducing agents that react with the organic acid metal salts referred to in the present invention to develop color, chelating agents, and sulfur compounds include tannic acid,
Gallic acid, alkaline earth metal sulfide, sodium thiosulfate,
Thiourea, hexamethylenetetramine, pyrogallol,
Hydroquinone, spiroindane, protocatechuic acid,
Thiosemicarbazides, thiourea derivatives, dithiooxamides, thioacedamide, metal salts, NN-disubstituted rubeanic acid, tin compounds, Zn salts of dithiosalvamic acid, organic polyhydroxy compounds, thiosulfates, phenetidine hydrochloride, heterohydrazine derivatives, Examples thereof include carbamic acid ester, aromatic polyhydroxy compound, and spirobenzopyran. The organic acid metal salts include ferric stearate,
Ni, Co, Cu and Pb salts of stearic acid, heavy metal salts of oxalic acid (Ag, Pb, Hg), tin stearate, silver behenate, silver stearate, ferric beargonate, lead caproate, nickel stearate. , Nickel acetate, ammonium molybdate, stearic acid or behenic acid Ni or Co salt, bismuth compound, stearic acid Cu or Fe salt, silver oxalate or mercury salt, stearate, organic acid iron, water-soluble Pb or Cb salt,
Examples thereof include molybdates of organic amines and organic acid metal salts.

Further, the color-forming substance capable of forming a color with the organic base as used in the present invention is an alkaline substance which causes coloration or color change.
A PH indicator, a fluorescein derivative, a phenolphthalein derivative, a substance that causes a discoloration phenomenon by being oxidized or reduced in a broad sense due to the change of the PH value to the alkaline side, and a ninhydrin derivative are used. Representative examples are shown below.

Examples of the organic base in the present invention include the following general formula [In the formula, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, amidine, cyano, or heterocyclic. Represents a ring residue, R ₆ is lower alkylene, phenylene, naphthylene, or (In the formula, X is lower alkylene, —SO ₂ —, —S ₂ —, —S
Represents a —, —O—, —NH— or —heavy bond),
Examples of the aryl group in the formula include those having a substituent selected from lower alkyl, alkoxy, nitro, acylamino, alkylamino group and halogen].

In addition to the above guanidine derivative, the following general formula, [In the formula, R ₇ , R ₈ and R ₉ represent hydrogen, alkyl having up to 18 carbon atoms, substituted alkyl of amino group, cycloalkyl, aralkyl and heterocyclic residue, and R ₇ , R ₈ and R ₉ At least 2
And a compound other than N in the general formula is bonded to form a ring together with N in the general formula].

Among the combinations of the basic dye precursor and the color developer described above, when at least one photo-oxidizing agent is used as the color developer, this combination can also be used as the photo-coloring material. The photo-oxidant in this case is activated by irradiation and reacts with the leuco dye to produce a colored image against the background of unirradiated and thus unchanged material.

Leuco dyes that can be easily colored by photo-oxidizing agents include
For example, those described in US Pat. No. 3,445,234 are included, and specific examples thereof are as follows.

(A) Aminotriarylmethane (b) Aminoxanthene (c) Aminothioxanthene (d) Amino-9,10-dihydroacridine (e) Aminophenoxazine (f) Aminophenothiazine (g) Aminodihydrophenazine (h) Amino Diphenylmethane (i) leucoindamine (j) aminohydrocinnamic acid (cyanoethane, leucomethine) (k) hydrazine (l) leucoin digoid dye (m) amino-2,3-dihydroanthraquinone (n) tetrahalo-p, p ′ -Biphenol (o) 2- (p-hydroxyphenyl) -4,5-diphenylimidazole (p) phenethylaniline Of these leuco dyes, those from (a) to (i) lose one hydrogen atom. As a result, the leuco dyes from (j) to (p) are colored as dyes. One of generating the parent dye losing a hydrogen atom. Of these, aminotriarylmethane is preferred. Generally preferred types of aminotriarylmethanes are those in which at least two of the aryl groups are (a) R ₁ and R ₂ are each hydrogen, C ₁ -C ₁₀ alkyl, 2-hydroxyethyl, 2-cyanoethyl,
Or a R ₁ , R ₂ , N-substituent in a position remote from the bond to the methane carbon atom, such as a group selected from benzyl, and (b) lower alkyl (C is 1 to 4), lower alkoxy A phenyl group having a group ortho to the methane carbon atom selected from (C is 1-4), fluorine, chlorine, or bromine; and the third aryl group is the same as the first two or They may be different, and if different, (a) lower alkyl, lower alkoxy, chlorine, diphenylamino, cyano, nitro, hydroxy, fluorine or bromine, alkylthio, arylthio, thioester, alkylsulfone, sulfonic acid, sulfonamide , Phenyl which may be substituted with alkylamide, arylamide, etc .; (b) substituted with amino, di-lower alkylamino, alkylamino (C) alkyl-substituted pyridyl; (d) quinolyl (e) alkyl-substituted indolinidene, a class of aminotriarylmethanes and acid salts thereof. R ₁ and R ₂ are hydrogen or carbon atoms 1 to
It is preferably 4 alkyl, especially preferably all 3 aryl groups are the same.

A preferred photo-oxidizing agent that develops an oxidatively-colorable leuco dye is inactive until exposed to actinic radiation such as visible light, ultraviolet rays, infrared rays, X-rays and the like. Various photo-oxidizing agents have different peak sensitivities throughout the spectrum depending on the structure of the compound. Therefore, the particular photo-oxidant chosen will depend on the nature of the actinic radiation. When exposed to such radiation, the photo-oxidant produces an oxidant that oxidizes the color-forming agent to its color-forming form.

Typical photo-oxidizing agents include carbon tetrabromide, N-bromosuccinimide, halogenated hydrocarbons such as tribromomethylphenyl sulfone described in U.S. Pat. Nos. 3,042,515 and 3,502,476, The Photographic Society of Japan Spring 1968. Research presentation abstract, azide polymer described on page 55, US Patent 3,
282,693 2-azidobenzoxazole, benzoyl azide, azide compounds such as 2-azidobenzimidazole, and 3-ethyl-1-methoxy-2-pyridothiacyanine perchlorate described in U.S. Pat.No. 3,615,568, 1- Methoxy-2-methylpyridinium-p-
Compounds such as toluene sulfonate, loffin dimer compounds such as 2,4,5-triarylimidazole dimer described in JP-B-62-39,728, compounds such as benzofenone, p-aminophenyl ketone, polynuclear quinone, thioxanthenone, and It includes, but is not limited to, at least one photo-oxidizer compound selected from the group consisting of mixtures of the above compounds.

The first color-developing layer and the second color-developing layer may be a combination of the different color development reactions described above, or may be a combination of the same color development reactions having different color hues.

Further, the energy for causing the color formation reaction in the first color development layer and the second color development layer is thermal energy, pressure, light energy,
Any energy such as electric energy may be used, or a combination of these may be used.

The material that causes the above color reaction is from the viewpoint of improving transparency,
Part of the components are microencapsulated from the viewpoint of raw storage stability (prevention of fog), such as preventing contact between the color developer and developer at room temperature, and control of color development sensitivity such that color is developed with the desired applied energy. Can also be used.

The wall material of the above microcapsules, polyurethane, polyurea, polyester, polycarbonate,
Urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer, styrene-acrylate copolymer, gelatin, polyvinylpyrrolidone, polyvinyl alcohol and the like can be mentioned. In the present invention, two or more of these polymer substances may be used in combination.

In the present invention, among the above polymeric substances, polyurethane, polyurea, polyamide, polyester, polycarbonate and the like are preferable, and polyurethane and polyurea are particularly preferable.

The microcapsules used in the present invention are preferably microencapsulated by emulsifying a core substance containing a reactive substance such as a color former, and then forming a wall of a polymer substance around the oil droplets. In this case, the reactant forming a polymer substance is added inside the oil droplet and / or outside the oil droplet.
Details of the microcapsules that can be preferably used in the present invention, such as the preferred method for producing the microcapsules, are described in, for example, JP-A-60-242094.

Here, as the organic solvent for forming the oil droplets, generally, it can be appropriately selected from among high-boiling oil, in particular, when using an organic solvent suitable for dissolving the developer, It is preferable because it has excellent solubility in a color-forming agent, can increase the density and color-developing rate of color formation during thermal printing, and can reduce fog.

When making a microcapsule, it can be made from an emulsion containing 0.2 wt% or more of the component to be microencapsulated.

In the present invention, the size of the microcapsules is preferably, for example, 10 μm or less, more preferably 2 μm or less, according to the measurement method described in JP-A-60-214990.

 In the present invention, it is also possible to use a color forming aid.

When heat energy is used as the applied energy, the color-forming aid that can be used in the present invention is a substance that increases the color-developing density during heating printing or lowers the minimum color-developing temperature. Substance, color former,
To lower the melting point of the developer or diazo compound layer or lower the softening point of the capsule wall to create a situation in which the diazo, basic substance, coupling component, color former, and developer easily react. Is.

Examples of the color-forming aid include phenol compounds, alcoholic compounds, amide compounds, sulfonamide compounds, and the like, and specific examples include p-tert-octylphenol,
p-benzyloxyphenol, phenyl p-oxybenzoate, benzyl carbanylate, phenethyl carbanylate, hydroquinone dihydroxyethyl ether, xylylenediol, N-hydroxyethyl-methanesulfonic acid amide, N-phenyl-methanesulfonic acid amide, etc. A compound can be mentioned. These may be contained in the core substance or may be added outside the microcapsules as an emulsified dispersion.

The color forming material of the present invention can be coated using a suitable binder.

As the binder, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, arabic rubber, gelatin, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic ester, ethylene-vinyl acetate copolymer. Various erjons such as The amount used is 0.5 to 5 g / m ² in terms of solid content.

In the present invention, it is essential to provide an intermediate layer between the first color-developing layer and the second color-developing layer. In the present invention, a water-soluble polyanion polymer is gelled with a polyvalent cation as the intermediate layer. Use layers.

The water-soluble polyanion polymer is preferably a polymer having a carboxyl group, a sulfonic acid group or a phosphoric acid group, and particularly preferably a water-soluble polyanion polymer having a carboxyl group. Examples of preferable water-soluble polyanionic polymers include natural or synthetic polysaccharide gums (for example, alkali metal alginate, guar gum, gum arabic, carrageenan, pectin, tragacanth gum, xanthene gum, etc.), acrylic acid or methacrylic acid. Examples thereof include polymers and copolymers thereof, polymers of maleic acid or phthalic acid and copolymers thereof, cellulose derivatives such as carboxymethyl cellulose, gelatin, agar and the like, among which alkali metal alginate is preferable. The water-soluble polyanionic polymer has a molecular weight of 5,000 to 10,000.
Is preferred, and particularly from 10,000 to 40,000 is preferred from the viewpoint of the barrier properties and the suitability for production which are the objectives of the present invention. Examples of the polyvalent cation include salts of alkaline earth metals and other polyvalent metals (for example, CaCl ₂ , BaCl ₂ , Al ₂ (SO ₄ ) ₃ and ZnSO.
₄ ), polyamines (eg ethylenediamine, diethylenetriamine, hexamethylenediamine, etc.) and polyimines are preferable.

Examples of other preferable intermediate layers in the present invention include an ion complex of a water-soluble polyanionic polymer and a water-soluble polycationic polymer. In this case, the various water-soluble polyanion polymers described above can be used as the water-soluble polyanion polymer.

As the water-soluble polycationic polymer, proteins having a plurality of reactive nitrogen-containing cationic groups, polypeptides such as polylysine, polyvinylamines, polyethyleneamines, polyethyleneimines and the like are preferable.

When making an intermediate layer using these materials,
In order to prevent rapid gelation during coating, it is preferable to apply either one of the materials in the first color forming layer or the second color forming layer, but it is also possible to adjust the temperature or PH or to use one material It is also possible to include the other material in the second coloring layer while containing it in the first coloring layer.

The coating amount of the preferable intermediate layer is 0.05 g / m ² to ⁵ g / m ² ,
More preferably from ^{0.1g / m 2 ~2g / m 2} .

In the present invention, for the purpose of preventing fog and increasing whiteness, a white pigment may be added to the coloring layer or the intermediate layer, or a layer containing a white pigment may be additionally applied.

Examples of preferable white pigments include talc, calcium carbonate, calcium sulfate, magnesium carbonate, magnesium hydroxide, alumina, synthetic silica, titanium oxide, barium sulfate, kaolin, calcium silicate, urea resin and the like.

 Further, it is possible to provide a protective layer on the uppermost layer.

The protective layer is a pigment, a metal soap, a water-soluble polymer such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, methyl cellulose, ethyl cellulose, carboxymethyl cellulose or hydroxyethyl cellulose.
A wax, a crosslinking agent, or the like is used.

Pigments include zinc oxide, calcium carbonate, barium sulfate,
There are titanium oxide, lithopone, talc, sekiseki, kaolin, aluminum hydroxide, amorphous silica, etc., and their addition amount is 0.05 to 2 times the total weight of the polymer, particularly preferably 0.1.
~ 5 times the amount.

Metal soaps include emulsions of higher fatty acid metal salts such as zinc stearate, calcium stearate and aluminum stearate, and are added in an amount of 0.5 to 20% by weight, preferably 1 to 10% by weight based on the total weight of the protective layer. To be done.
Examples of the wax include paraffin wax, microcrystalline wax, carnauba wax, methyl roll stearamide, polyethylene wax, and emulsion of silicone, which are 0.5 to 40% by weight, preferably 1 to 20% by weight of the total weight of the protective layer. Added in quantity.

Further, in the protective layer, a surfactant, a polymer electrolyte or the like for preventing the heat-sensitive recording material from being charged may be added. The solid coating amount of the protective layer is usually preferably 0.2-5 g / m ^2, more preferably from 1g~3g / m ^2.

For more information on protective layers, see Pulp and Paper Technology Times.
No. 8 (1985).

Further, an undercoat layer may be provided for the purpose of enhancing the adhesiveness between the support and the color forming layer, improving smoothness, and providing heat insulation.

As a material for the undercoat layer, a water-soluble polymer such as gelatin, a synthetic polymer latex, nitrocellulose or the like is used. The coating amount of the undercoat layer is preferably in the range of ^{0.1g / m 2 ~2.0g / m 2} , preferably in the range particularly ^{0.2g / m 2 ~1.0g / m 2} .

Examples of the support used in the present invention include paper, synthetic paper, polymer film and the like.

In the present invention, as the paper used for the support, heat-extractable pH 6-9 neutral paper sized with a neutral sizing agent such as alkyl ketene dimer (described in JP-A-55-14281) is used. It is advantageous in terms of storage stability over time.

In order to prevent the coating liquid from penetrating into the paper, Japanese Patent Laid-Open No. 57-116687
No. Moreover, paper having a Bekk smoothness of 90 seconds or more is advantageous.

Further, the optical surface roughness described in JP-A-58-136492 is 8
Paper having a density of 0.9 g / cm ² or less and an optical contact rate of 15% or more as described in JP-A-58-69097, described in JP-A-58-69097. Canadian Standard Freeness (J
Paper made from pulp that has been beaten to 400 cc or more with IS P8121) to prevent penetration of the coating liquid, the glossy surface of the base paper made by the Yankee machine as described in JP-A-58-65695 is used as the coating surface, Improving color density and resolution,
The paper described in JP-A-59-35985, which has been subjected to corona discharge treatment on the base paper to improve the coating suitability, is also used in the present invention and gives good results. Any of these other supports used in the field of ordinary thermosensitive recording paper can be used as the support of the present invention.

In the present invention, a back layer may be provided on the back surface of the support for the purpose of straightening curl, preventing electrification and improving slipperiness.
As the constituent components of the back layer, it is preferable to use the same components as those of the protective layer.

Among the supports used in the present invention, as the polymer film, a film of polyester such as polyethylene terephthalate or polybutylene terephthalate, a film of a cellulose derivative such as a cellulose triacetate film, a polysuriten film, a polypropylene film, or a polyolefin film such as polyethylene is used. Therefore, these can be used alone or in combination.

As the thickness of the support is used 20 ~ 200μ,
Particularly, those having a thickness of 50 to 100 μm are preferable.

The coating liquid according to the present invention is a generally well-known coating method, for example, a dip coating method, an air knife coating method,
Curtain coating method, roller coating method, doctor coating method, wire bar coating method, stide coating method, gravure coating method, or extrusion coating method using a hopper described in U.S. Pat.No. 2,681,294 You can If necessary, U.S. Patent Nos. 2,761,791, 3,508,947, 2,941,898,
It is also possible to apply simultaneously in two or more layers by the method described in No. 3,526,528 specification, Yuji Harazaki, "Coating Engineering", page 253 (published by Asakura Shoten in 1973), etc. A suitable method can be selected according to the coating speed and the like.

In the coating liquid used in the present invention, a pigment dispersant, a thickener, a flow modifier, a defoaming agent, a foam suppressor, a release agent, a colorant, a surfactant, etc. may be appropriately blended, if necessary. As long as it does not impair the characteristics, it can be used.

In carrying out the present invention, the color-developing layer is not limited to two layers, and a plurality of layers may be provided thereon. In this case, a coloring layer having a different coloring hue is usually provided.

When the color forming layer is provided in multiple layers, at least one intermediate layer disclosed in the present invention is provided.

 It is also possible to provide a coloring layer on both sides of the support.

When the support is transparent, such an embodiment is preferably used.

<Example> The present invention will be further described below with reference to Examples, but the present invention is not limited thereto.

 In addition, "part" indicating the addition amount represents "part by weight".

Example 1. Preparation of capsule liquid A 3.4 parts of diazo compound Tricresyl phosphate 6 parts Methylene chloride 12 parts Trimethylolpropane trimethacrylate 18 parts Takenate D-11ON (75 wt% ethyl acetate solution) (Takeda Pharmaceutical Co., Ltd. (trade name)) 24 parts are mixed, and polyvinyl chloride is mixed. Alcohol (Kuraray PVA-217E)
The mixture was added to an aqueous solution consisting of 63 parts of 8 wt% aqueous solution and 100 parts of distilled water, then emulsified and dispersed at 20 ° C to obtain an emulsion having an average particle size of 2μ, and the obtained emulsion was stirred at 40 ° C for 3 hours. I continued.

After cooling this solution to 20 ° C, Amberlite IR-120B
(Rohm and Haas (trade name)) (100 cc) was added, and the mixture was stirred for 1 hour and filtered to obtain a capsule liquid.

Preparation of coupler / base dispersion A I. Polyvinyl alcohol (Kuraray PVA205) 4% by weight aqueous solution 170 parts II. Coupler 14 parts Triphenylguanidine (base) 6 parts Coloring aid Mix 14 parts and add Dyno Mill (Willie A. Bacofen.
Dispersed by A.G. (trade name), average particle size 3
A dispersion of μ was obtained.

Preparation of Heat Sensitive Dispersion A 2-anilino-3-methyl-N-methyl-N-cyclohexylaminofluorane as a color former, bisphenol A as a developer and β-naphthylbenzyl ether as a sensitizer 20 g each of 100 g Each of them was dispersed with a 5% aqueous solution of polyvinyl alcohol (Kuraray PVA-105) in a ball mill for 24 hours to adjust the volume average particle diameter to 3 μm or less. Calcium carbonate (Unibur70 Shiraishi Kogyo Co., Ltd.) was used as the pigment, and 80 g was dispersed in a homogenizer together with 160 g of a 0.5% solution of sodium hexametaphosphate and used. Each of the dispersions prepared as described above was mixed with 2-anilino-3-methyl-
Heat-sensitive dispersion A was obtained by mixing 5 g of N-methyl-N-cyclohexylaminofluorane dispersion, 10 g of bisphenol A dispersion, 10 g of β-naphthylbenzyl ether dispersion and 15 g of calcium carbonate dispersion.

Preparation of protective layer liquid A Silica-modified polyvinyl alcohol (PVA manufactured by Kuraray Co., Ltd.)
R2105) 10 wt% liquid 10 parts Colloidal silica (Snowtex 3 manufactured by Nissan Kagaku Co., Ltd.)
0) 30 wt% liquid 5 parts Zinc stearate (Hydrin Z- manufactured by Chukyo Yushi Co., Ltd.)
7) 30% by weight solution 0.42 parts Paraffin wax (Hydrin P- manufactured by Chukyo Yushi Co., Ltd.)
7) 0.42 parts of a 30% by weight solution was mixed to obtain a protective layer solution A.

Preparation of recording sheet After applying the heat-sensitive dispersion A to a high-quality paper having a basis weight of 50 g / m ^{2 so} that the dry coating amount becomes 6 g / m ² , the intermediate layer is sodium alginate (Snow Algin SH Fuji Chemical Co., Ltd.). ) A 3% aqueous solution was applied such that the dry coating amount was 0.5 g / m ² .

Then 6 parts of capsule liquid A, coupler / base dispersion salt A
5.5 parts, 0.5 part of polyethyleneimine (average molecular weight 75) 30% aqueous solution A mixed solution was applied so that the dry coating amount would be 6 g / m ^2, and then the protective layer liquid A would be dried coating amount of 2 g / m ² . To obtain a recording sheet. The coating was performed using a wire bar and then dried in an oven at 50 ° C.

After heat-applying the obtained recording sheet with low energy (thermal head voltage: 15 V, printing time: 0 to 2.5 msec), the recording sheet was irradiated with light from Recopy Super Dry 100 type for 10 seconds to obtain a diazo coloring layer. Then, thermal printing was performed at a higher energy than the printing energy. (Thermal head voltage 15 V, printing time 2.5 to 5 msec) The obtained image was a clear two-color print in which the low energy printing portion was red and the high printing energy portion was black.

Further, this sheet showed no increase in fog and no change in print density even after being stored for a long time.

Comparative Example 1. A recording sheet was obtained in the same manner as in Example 1 except that the intermediate layer was not provided.

The obtained sheet was colored in the same manner as in Example 1,
The color density of black was slightly lower than that in Example 1.

Further, when the sample stored for a long period of time was examined, yellow to red fog was observed. When this was printed and colored, the color density of black was extremely reduced.

Example 2. Preparation of coupler / base dispersion B I. Polyvinyl alcohol (Kuraray PVA-205) 5% by weight aqueous solution 170 parts II. Coupler 2-hydroxy-3-naphthoic acid anilide 1
2 parts 2,4-bis (benzoylacetamide) toluene 2 parts triphenylguadinine (base) 6 parts III. Mix 14 parts and add Dyno Mill (Willie A. Bacofen.
It was dispersed by A.G. (trade name) to obtain a dispersion liquid having an average particle diameter of 3μ.

Preparation of Capsule Liquid B As a basic colorless dye, the following compound (CIBA Pergasc
ript Red I-6-B) 14 parts 1-phenyl-1-xylethane 55 parts Methylene chloride 55 parts Sumithorpe 200 (UV absorber made by Sumitomo Chemical Co., Ltd.) 2 parts Takenate D-110N (Takeda Pharmaceutical Co., Ltd. (trade name)) 60 parts The mixture was mixed and added to an aqueous solution consisting of 100 parts of 8% by weight polyvinyl alcohol aqueous solution and 40 parts of distilled water, and then emulsion-dispersed at 20 ° C. to obtain an emulsion dispersion having an average particle size of 1 μm. next,
The obtained emulsion was continuously stirred at 40 ° C. for 3 hours to obtain a capsule liquid B.

Preparation of Developer Dispersion Liquid A (Emulsified Dispersion) 8 parts of the developer (a) represented by the following structural formula, 4 parts of (b) and 3 parts of (c) were added to 1-phenyl-1-xylylethane 8:
And 30 parts of ethyl acetate. The resulting developer solution was mixed with 100 parts of an 8% by weight polyvinyl alcohol aqueous solution and 150 parts of water.
Parts and an aqueous solution of 0.5 parts of sodium dodecylbenzene sulfonate were mixed and emulsified to obtain an emulsified dispersion having a particle size of 0.5 μm.

Preparation of protective layer liquid B Silica-modified polyvinyl alcohol (PVA manufactured by Kuraray Co., Ltd.)
R2105) 10 wt% aqueous solution 15 parts Colloidal silica (Nissan Chemical Co., Ltd. Snowtex 3
0) 30% by weight aqueous solution 8.5 parts Zinc stearate (Hydrin York manufactured by Chukyo Yushi Co., Ltd.) 30% by weight aqueous solution 0.42 parts Paraffin wax (Cerosol D- manufactured by Chukyo Yushi Co., Ltd.)
130) 22 wt% aqueous solution 0.54 parts Silica (Mizukasil P-832 manufactured by Mizusawa Chemical Co., Ltd.) 33 wt% aqueous dispersion 1.9 parts was mixed to obtain a protective layer liquid B.

Preparation of recording sheet After corona treatment is applied to a 75μ thick biaxially stretched polyethylene terephthalate film, a mixed solution of 5.0 parts of capsule liquid B and 10.0 parts of developer liquid A is applied at a dry coating amount of 6 g / m ² Was applied so that Then, a 3 wt% aqueous solution of sodium alginate (Snow Algin SH Fuji Chemical Co., Ltd.) was applied as an intermediate layer so that the dry coating amount was 0.5 g / m ^2, and then the capsule liquid A was used.
6 parts, coupler / base dispersion B5.5 parts, calcium chloride 10
A mixed solution of 0.5 part by weight of an aqueous solution was applied so that the dry application amount was 6 g / m ² . After that, the protective layer liquid B was applied at a dry coating amount of 2 g / m ²
To obtain a recording sheet.

The coating was performed using a wire bar and then dried in an oven at 50 ° C.

The obtained recording sheet was thermally printed with low energy (thermal head voltage: 15, printing time: 0 to 2.5 msec), and then light-irradiated with a Ricopy Super Dry 100 type for 10 seconds to fix the diazo coloring layer. After that, thermal printing was performed with high energy compared to the printing energy (thermal head voltage 15V,
Printing time 2.5-5msec).

The obtained image was a clear two-color print in which the low energy print portion was black and the high print energy portion was red. The image was observed as a clearer image when observed from the surface of the transparent sheet opposite to the printed part.

In addition, even if this sheet was stored for a long time, there was no increase in fog or change in print density.

Comparative Example 2. A recording sheet was obtained in exactly the same manner as in Example 2 except that polyvinyl alcohol (PVA-205 Kuraray Co., Ltd.) was used as the intermediate layer instead of sodium alginate.

When the obtained sheet was colored in the same manner as in Example 2, the black color density was slightly lower than that in Example 1.

Further, when the sample stored for a long period of time was examined, fog was observed in yellow to black. When this was printed and colored, the color density of black was extremely lowered.

Claims (2)

(57) [Claims] 1. A multicolor recording material comprising, on one surface of a support, at least two color-developing layers, each of which has a different color due to a color-developing reaction, provided in multiple layers, and a water-soluble layer between each color-developing layer. A multicolor recording material comprising an intermediate layer obtained by gelling a polyanionic polymer with a polyvalent cation. 2. The multicolor recording material according to claim 1, wherein the intermediate layer contains an ion complex of a water-soluble polyanionic polymer and a water-soluble polycationic polymer.