JP2000127626A - Thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal recording material of high coloring density whose thermal recording layer is excellent in water resistance, oil resistance, and adhesive strength, and its production method which is efficient and of high productivity. SOLUTION: In a thermal recording material having thermal recording layers on a support, at least one of the thermal recording layers is added with a substantially colorless coloring component A and a substantially colorless component B which develops color by reacting with the component A, and at least one of the components A, B is encapsulated into microcapsules produced in the presence of at least one surface active polymer containing at least 5 mole % of a unit expressed by a formula. In the formula, R is 4-22C aliphatic hydrocarbon group; A is 1-50C divalent aliphatic group; M is a cation which can form a salt with a sulfonic acid or a cationic radical; B is -O- or -NH-; m1 and m2 are each 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material having good sensitivity and excellent water resistance, oil resistance and adhesion strength of a heat-sensitive recording layer, and an efficient production method thereof.

[0002]

2. Description of the Related Art Thermal recording has recently been developed because its recording apparatus is simple, highly reliable, and requires no maintenance. As the heat-sensitive recording material, those utilizing a reaction between an electron-donating colorless dye and an electron-accepting compound,
Those utilizing a reaction between a diazonium salt compound and a coupler are widely known. Among them, those utilizing the reaction between a diazonium salt compound and a coupler are widely used for fixing type heat-sensitive recording materials and multi-color heat-sensitive recording materials because of the advantage of being capable of fixing.

It is useful to enclose one of the color-forming components in a thermoresponsive microcapsule from the viewpoint of the color-forming sensitivity, the robustness of the color-forming body and the storage stability. This microcapsule is usually a low boiling solvent,
For example, a color-forming component is dissolved in ethyl acetate or the like, a wall material is added to prepare an oil phase, and the oil phase is emulsified and dispersed in a water-soluble polymer aqueous solution to form oil phase fine particles. To form capsule walls by interfacial polymerization.

According to this method, a protective colloid made of a water-soluble polymer is formed around the oil phase fine particles, the emulsion stability of the emulsified oil droplets (oil phase fine particles), the viscosity adjustment of the aqueous phase liquid, and the prevention of capsule aggregation. Was useful. The water-soluble polymer also functions as a binder when forming a heat-sensitive recording layer with a coating solution. However, the types of water-soluble polymers that can be substantially used to satisfy the above functions are limited, and when the water-soluble polymer is present as a binder in the formed layer, the water resistance of the layer is low. There is a concern that it will be insufficient, and when a hydrophobic polymer is added to the thermosensitive recording layer to improve it and improve water resistance, the content of the entire binder increases, causing a decrease in sensitivity. There was a problem. For this reason, it was studied to obtain microcapsules containing a coloring component without using a water-soluble polymer.However, due to lack of stability of the oil phase fine particles, agglomeration occurs when the capsule wall is formed, and oil droplet breakage occurs. At present, satisfactory capsules cannot be obtained.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material which has a high color density of an image and which is excellent in water resistance, oil resistance and adhesion strength of a heat-sensitive recording layer. The second object of the present invention is to provide a method for producing a heat-sensitive recording material having high productivity and high efficiency without necessarily adding a water-soluble polymer, as described above. To provide.

[0006]

An object of the present invention is to provide a multicolor heat-sensitive recording material having a plurality of heat-sensitive recording layers provided on a support, wherein one of the coloring components is at least one of a specific surface-active polymer. This was achieved by encapsulation in microcapsules manufactured in the presence of the seed.

That is, in the heat-sensitive recording material of the present invention, in a heat-sensitive recording material having a heat-sensitive recording layer provided on a support, at least one of the heat-sensitive recording layers is provided with a substantially colorless color-forming component A (hereinafter referred to as an appropriate one). A color-forming component A) and a substantially colorless color-forming component B (hereinafter, appropriately referred to as a color-forming component B) which reacts with the color-forming component A to form a color, and the color-forming component A and the color-forming component B Is encapsulated in a microcapsule produced in the presence of at least one kind of a surfactant polymer containing at least 5 mol% of a unit represented by the following general formula (I).

[0008]

Embedded image

In the general formula (I), R represents an aliphatic hydrocarbon group having 4 to 22 carbon atoms. A represents a divalent aliphatic group having 1 to 50 carbon atoms. M represents a cation or a cationic root capable of forming a salt with sulfonic acid. B represents -O- or -NH-. m1 and m2 each represent 0 or 1. In the present invention, the thermosensitive recording layers of cyan, magenta, and yellow are sequentially provided on a support to be used as a multicolor thermosensitive recording material.

The method for producing a heat-sensitive recording material according to the present invention according to claim 4 is a method for producing a heat-sensitive recording material having a heat-sensitive recording layer provided on a support, wherein the substantially colorless color-forming component A is provided. A surface activity containing at least 5 mol% of a unit represented by the general formula (I), which contains at least one of the substantially colorless coloring component B which reacts with the coloring component A to form a color. At least one of the polymers
A step of preparing in the presence of a seed, a step of preparing a coating solution for the heat-sensitive recording layer containing a microcapsule containing either the color-forming component A or the color-forming component B, and the other color-forming component, Forming a thermal recording layer by applying the thermal recording material layer coating solution thereon.

The combination of the color-forming component A and the color-forming component B in the present invention is preferably (1) a combination of an electron-donating dye precursor and a developer, or (2) a combination of a diazonium salt compound and a coupler.

When the heat-sensitive recording material of the present invention is used as a multicolor heat-sensitive recording material, preferred embodiments include a heat-sensitive recording layer A containing an electron-donating dye precursor and an electron-accepting compound as a color developer; A structure in which a salt compound and a heat-sensitive recording layer B containing a coupler that reacts with the diazonium salt compound to form a color are laminated. The heat-sensitive recording layer has a maximum absorption wavelength of 360 ± 20 nm and a diazonium salt compound. It contains a thermosensitive recording layer B-1 containing a coupler which reacts with a diazonium salt compound to form a color, a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm, and a coupler which forms a color by reacting with the diazonium salt compound. It is desirable to have a structure in which the thermosensitive recording layer B-2 is laminated.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the color-forming components used in the heat-sensitive recording layer include at least a substantially colorless color-forming component A and a substantially colorless color-forming component B, which reacts and forms a color. And conventionally known ones can be used. The color-forming component A and the color-forming component B used in the present invention are components that cause a color-forming reaction when they come into contact with each other, and examples of the combinations thereof include the following (A) to (W). However, in the heat-sensitive recording material of the present invention, (a) a reaction utilizing a reaction between a diazonium salt compound and a coupling component (hereinafter, appropriately referred to as a coupler), or (b) an electron-donating colorless dye and an electron acceptor Those utilizing a reaction with a sexual compound are preferably used.

(A) A combination of a photodegradable diazonium salt compound and a coupler. (B) A combination of an electron-donating dye precursor and an electron-accepting compound. (C) A combination of a metal salt of an organic acid such as silver behenate and silver stearate with a reducing agent such as protocatechinic acid, spiroindane and hydroquinone. (D) A combination of iron salts of long-chain fatty acids such as ferric stearate and ferric myristate with phenols such as tannic acid, gallic acid and ammonium salicylate. (E) Organic acid heavy metal salts such as nickel, cobalt, lead, copper, iron, mercury, and silver salts such as acetic acid, stearic acid, and palmitic acid; and alkaline earth metals such as calcium sulfide, strontium sulfide, and potassium sulfide. A combination with a sulfide, or a combination of the organic acid heavy metal salt with an organic chelating agent such as s-diphenylcarbazide or diphenylcarbazone. (F) A combination of a heavy metal sulfate such as a sulfate of silver, lead, mercury, sodium and the like, and a sulfur compound such as sodium tetrathionate, sodium thiosulfate and thiourea. (G) ferric fatty acid salts such as ferric stearate;
Combinations with aromatic polyhydroxy compounds such as 3,4-hydroxytetraphenylmethane.

(H) A combination of an organic acid metal salt such as oxalate and mercury oxalate with an organic polyhydroxy compound such as polyhydroxy alcohol, glycerin and glycol. (Ii) A combination of a ferric fatty acid salt such as ferric pelargonic acid or ferric laurate, and a thiocesylcarbamide or isothiocesylcarbamide derivative. (N) A combination of a lead salt of an organic acid such as lead caproate, lead pelargonate or lead behenate with a thiourea derivative such as ethylenethiourea or N-dodecylthiourea. (R) A combination of a heavy metal salt of a higher fatty acid such as ferric stearate and copper stearate with zinc dialkyldithiocarbamate. (Ii) Those that form an oxazine dye, such as a combination of resorcinol and a nitroso compound. (W) A combination of a formazan compound and a reducing agent and / or a metal salt.

Of these, in addition to the combination of the photodegradable diazonium salt compound and the coupler (a) and the combination of the electron donating dye precursor and the electron accepting compound (b) described above, The combination of the organometallic salt of (c) and the reducing agent is preferred.

The following is a typical combination (a).
Will be described. The compound used in the heat-sensitive recording layer containing the diazo compound used in the present invention and a coupler that reacts with the diazo compound when heated to form a color can be used to form a dye by reacting with the diazonium salt compound or the diazonium salt compound. Examples include a basic substance which is a color-forming aid for accelerating the reaction between the coupler and the diazonium salt compound and the coupler. The diazo compound in the present invention typically has a structure represented by the following formula, and these compounds can suppress the maximum absorption wavelength depending on the position and type of the substituent in the Ar portion.

[0018] Ar-N ₂ ⁺ X ^- where, Ar is an aryl group, X ^- represents an acid anion.

Specific examples of the diazonium salt compound in the present invention include 4- (N- (2- (2,4-di-
tert-amylphenoxy) butyryl) piperazino)
Benzenediazonium, 4-dioctylaminobenzenediazonium, 4- (N- (2-ethylhexanoyl)
Piperazino) benzenediazonium, 4-dihexylamino-2-hexyloxybenzenediazonium, 4-
N-ethyl-N-hexadecylamino-2-ethoxybenzodiazonium, 3-chloro-4-dioctylamino-2-octyloxyobenzenediazonium, 2,5
-Dibutoxy-4-morpholinobenzenediazonium,
2,5-octoxy-4-morpholinobenzenediazonium, 2,5-dibutoxy-4- (N- (2-ethylhexanoyl) piperazino) benzenediazonium, 2,
5-diethoxy-4- (N- (2- (2,4-di-te
acid anion salts such as rt-amylphenoxy) butyryl) piperazino) benzenediazonium, 2,5-dibutoxy-4-tolylthiobenzenediazonium, 3- (2-octyloxyethoxy) -4-morpholinobenzenediazonium; Diazonium salt compound D-1
~ 5. Particularly, hexafluorophosphate salt, tetrafluoroborate salt and 1,5-naphthalene sulfonate salt are preferable.

[0020]

Embedded image

Specific examples of the acid forming the diazonium salt include C _n F _{2n + 1} COOH (n is an integer of 1 to 9) and C _m F _{2m + 1} SO ₃ H (m is 1 to 9). , Boron tetrafluoride, tetraphenylboron, hexafluorophosphoric acid, aromatic carboxylic acid, and metal halides such as zinc chloride and tin chloride.

Among these diazonium salt compounds, particularly preferred compounds in the present invention are 300 to 400.
4- (N- (2-
(2,4-di-tert-amylphenoxy) butyryl) piperazino) benzenediazonium, 4-dioctylaminobenzenediazonium, 4- (N- (2-ethylhexanoyl) piperazino) benzenediazonium,
4-dihexylamino-2-hexyloxybenzenediazonium, 4-N-ethyl-N-hexadecylamino-2-ethoxybenzodiazonium, 2,5-dibutoxy-4- (N- (2-ethylhexanoyl) piperazino) Benzenediazonium, 2,5-diethoxy-4-
(N- (2- (2,4-di-tert-amylphenoxy) butyryl) piperazino) benzenediazonium and the compounds shown in the above specific examples D-3 to D-5. The maximum absorption wavelength of the diazonium salt compound referred to herein is a spectrophotometer (MPS-200, manufactured by Shimadzu Corporation) obtained by coating each compound with a coating film of 0.1 g / m ² to 1.0 g / m ^2.
0). When a diazo compound is used as the color-forming component of the heat-sensitive recording material of the present invention, it is preferable to use the diazo compound encapsulated in heat-responsive microcapsules.

Examples of the couplers used in the present invention, which react with the diazonium salt upon heating to give a color, include resorcinol, flurgurcine, and 2,3-dihydroxynaphthalene-6.
Sodium sulfonate, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-
Dihydroxy-6-sulfanylnaphthalene, 2-hydroxy-3-naphthoic acid anilide, 2-hydroxy-3
-Naphthoic acid ethanolamide, 2-hydroxy-3-
Naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid-N-dodecyloxypropylamide, 2-hydroxy-3-naphthoic acid tetradecylamide, acetanilide, acetoacetanilide, benzoylacetanilide, 2-chloro-5-octylacetate Acetanilide, 1-phenyl-3-methyl-5-pyrazolone, 1-
(2′-octylphenyl) -3-methyl-5-pyrazolone, 1- (2 ′, 4 ′, 6′-trichlorophenyl)
-3-benzamide-5-pyrazolone, 1- (2 ',
4 ', 6'-trichlorophenyl) -3-anilino-5
-Pyralone, 1-phenyl-3-phenylacetamido-5-pyrazolone, and the following compounds C-1 to C-6. These couplers are used in combination of two or more,
An image of any color tone can be obtained.

[0024]

Embedded image

In the present invention, a basic substance which acts as a color-forming aid is added for the purpose of making the system basic during thermal development to promote the coupling reaction. As such a basic substance, a water-insoluble or water-insoluble basic substance or a substance that generates an alkaline substance by heating is used. Specific examples of the basic substance include inorganic and organic ammonium salts, organic amines, amides, ureas and thioureas and their derivatives, thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, Examples include nitrogen-containing compounds such as imidazolines, triazoles, morpholines, piperidines, amidines, formazines, pyridines and the like. Specific examples of these include tricyclohexylamine, tribenzylamine, octadecylbenzylamine, stearylamine, allylurea, thiourea, methylthiourea, allylthiourea, ethylenethiourea, 2-benzylimidazole, 4-phenylimidazole, 2-phenylimidazole,
Phenyl-4-methylimidazole, 2-undecylimidazoline, 2,4,5-trifuryl-2-imidazoline, 1,2-diphenyl-4,4-dimethyl-2-imidazoline, 2-phenyl-2-imidazoline, , 2,
3-triphenylguanidine, 1,2-dicyclohexylguanidine, 1,2,3-tricyclohexylguanidine, guanidine trichloroacetate, N, N′-dibenzylpiperazine, 4,4′-dithiomorpholine, morpholinium trichloroacetic acid Salts, 2-aminobenzothiazole, 2-benzoylhydrazinobenzothiazole and the like. These basic substances can be used in combination of two or more.

In the present invention, particularly from the viewpoint of increasing the thermal sensitivity, the recording layer contains a fatty acid amide, an N-substituted aliphatic amide, a phenol derivative, a naphthol derivative, an alkoxy-substituted benzene, an alkoxy-substituted naphthalene, a hydroxy compound, an acid compound. Compounds such as compounds, sulfonamide compounds, ketone compounds, urea compounds, and esters can be added. These compounds reduce the melting point of the coupling component or the basic substance, or improve the heat permeability of the microcapsule wall, and as a result, function as a thermal sensitizer, and are used as a heat-fusible substance. Is also included. Here, the heat-fusible substance is a substance which is solid at normal temperature and melts by heating and has a melting point of 50 ° C. to 150 ° C., and is a substance which dissolves a diazo compound, a coupling component or a basic substance.

In the present invention, the coupling component is preferably used in an amount of 0.1 to 10 parts by weight, and the color-forming aid is preferably used in an amount of 0.1 to 20 parts by weight based on 1 part by weight of the diazo compound. The application amount of the diazo compound is 0.05 to 5.0.
It is desirably about g / m ² .

In the present invention, one of the coloring components such as the diazo compound and an electron-donating colorless dye described later is used by being encapsulated in a specific heat-responsive microcapsule. Is prepared by emulsifying a core substance to prepare an oil-in-water emulsion composition, and then forming a wall of a polymer substance around the oil droplets (oil phase fine particles). At the time of preparing this emulsion composition, it is necessary that the composition contains a surfactant polymer containing at least 5 mol% of a unit represented by the following general formula (I).

[0029]

Embedded image

In the general formula (I), R has 4 to 22 carbon atoms;
Preferably, it is represented by 6 to 18 aliphatic hydrocarbon groups. The aliphatic hydrocarbon group may be linear or branched, and may have an unsaturated bond.

Examples of the aliphatic hydrocarbon group include an alkyl group such as butyl, octyl, nonyl, dodecyl and octadecyl, and an alkenyl group such as a cis-9-octadecenyl group.

In the general formula (I), A has 1 to 50 carbon atoms.
Represents a divalent aliphatic group. As the divalent aliphatic group,
Examples thereof include an alkylene group, an alkyleneoxy group, a polyalkyleneoxy group, and an alkyleneoxy-alkylene group. Specific examples include ethylene, trimethylene, octamethylene, ethyleneoxy, polyethyleneoxy, and ethyleneoxy-trimethylene.

In the general formula (I), M represents a cation or a cationic root capable of forming a salt with a sulfonic acid group. Examples of the cation and the cationic root capable of forming a salt with a sulfonic acid group include hydrogen, sodium, potassium, lithium, calcium, barium, ammonium, and alkylammonium having 1 to 4 carbon atoms.

In the general formula (I), B represents —O— or —NH—
Represents m1 and m2 each represent 0 or 1.

The surfactant polymer contains at least 5 mol%, preferably at least 10 mol% of the unit represented by the general formula (I).

The surface active polymer may be a copolymer or a homopolymer. In the case of a copolymer, the unit represented by the general formula (I) may be 5 mol% to 9 mol%.
Preferably, it contains 5 mol%, particularly preferably about 10 to 95 mol%. The unit represented by the general formula (I) and the unit to be copolymerized may be one kind or two or more kinds.

The unit to be copolymerized (for example, a benzene ring or a naphthalene ring having a methylene group) may have a substituent, and it is preferable that at least one substituent is substituted. As the substituent, an alkyl group (preferably an alkyl group having 4 to 22 carbon atoms, for example, a butyl group, an octyl group, a nonyl group, a dodecyl group, an octadecyl group, etc.), a halogen atom (eg, a chlorine atom, a bromine atom, Iodine atom, etc.), hydroxy group, alkoxy group (alkoxy group having 4 to 22 carbon atoms is preferable, for example, octyloxy group, hexyloxy group, dodecyloxy group, -hydroxyethoxy group and the like), haloalkoxy group (4 carbon atoms).
To 22 haloalkoxy groups, for example, β-chloroethoxy, β-bromoethoxy, etc.).

Specific examples of the units to be copolymerized include:
Examples include units represented by the following structural formulas (i) to (vii). However, in structural formulas (i) to (iv), R ₀ represents an aliphatic hydrocarbon group having 4 to 22 carbon atoms. Examples of the aliphatic hydrocarbon group include the same as those described above.

[0039]

Embedded image

[0040]

Embedded image

The molecular weight of the surfactant polymer is not particularly limited, but is preferably about 600 to about 10,000, particularly preferably 900 to 8,000.

Specific examples of the surfactant polymer include compounds represented by the following structural formulas (A) to (N). However, each of the structural formulas (A) to (N) is a surface-active polymer which is contained at a ratio described below the structural unit.

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

The surfactant copolymer can be synthesized by a conventional method. For example, synthesis of a formalin polycondensate of an alkylphenol is described in Kogaku Kagaku Magazine, Vol. 66, p.
963), and can be easily synthesized according to the method described in Oil Chemistry, Vol. 12, p. 625 (1963). The introduction of sulfonic acid is described in, for example, Industrial Chemical Magazine No. 7
3, 563 (1970), 59: 221 (19)
56) and J.M. Am. Chem. Soc. , Vol. 77, page 2496 (1955) and the like.

The optimum amount of the surfactant polymer varies depending on the type of the color-forming component used, the type and amount of the organic solvent, and in some cases, the type and amount of the low-molecular-weight surface-active polymer used in combination. However, the usable range is 0.5 to 50% by weight based on the dispersed oil phase material. When the surfactant polymer is used for preparing an emulsion composition for producing microcapsules, it may be added after being dissolved in a suitable solvent. Solvents that can be used include ethyl acetate, isopropyl acetate, methyl ethyl ketone, cyclohexane, benzene, toluene and the like. There is no particular limitation on the timing of addition, but usually, the surfactant polymer dissolved in a solvent is used by mixing it with an oil phase substance containing a coloring component. By using this surface-active polymer, the oil phase fine particles containing the coloring component can be present in a stable state in the system without using a water-soluble polymer or the like, and thus contain a high concentration of the coloring component. Microcapsules can be obtained.

In the method for producing a heat-sensitive recording material of the present invention, there is no particular limitation on the apparatus used for preparing the emulsified dispersion, and a high-speed stirring type disperser having a large shearing force, a dispersing device applying high-intensity ultrasonic energy, A known dispersing device, emulsifying device, or the like, such as a mixer, can be used. Specific examples include a colloid mill, a homogenizer, a capillary type emulsifying apparatus, a liquid siren, an electromagnetic strain type ultrasonic generator, and an emulsifying apparatus having a Ballman flute. The high-speed stirring type disperser means that a disperser, a polytron, a homomixer, a homo-blender, a Keddy mill, a jet agitator, etc., are rotated at a high speed (500 to 15,000 r.
pm, preferably 2,000 to 4,000 rpm).

When the above-mentioned surfactant polymer is used for the preparation of this emulsion composition, it can be used not only alone but also in combination with other non-polymerizable surfactants. From the viewpoint of preparing a stable emulsified dispersion, it may be preferable to use a low-molecular surfactant in combination rather than using the emulsion alone. The surfactant polymer can be used in combination with one or more of a so-called anionic surfactant and a nonionic surfactant. Examples of the anionic surfactants, 1 hydrophobic group up to 8 to 30 carbon atoms in the molecule and -SO ₃ M or -O
It is preferable to use a compound having an SO ₃ M group (where M is the same as M in the general formula (I)). Compounds of this type are described in Ryohei Oda and Kazuhiro Teramura, “Synthesis and Application of Surfactants” (Maki Shoten), and W. Per
RY "Surface Active Agent"
(Interscience Publication
s Inc. New York).

As the nonionic surfactant, it is preferable to use a nonionic surfactant described in JP-A-48-30933 and a fatty acid ester-based surfactant of a polyhydric alcohol. The fatty acid ester-based surfactant of a polyhydric alcohol has at least two, preferably at least three, hydroxyl groups, and more preferably has 6 to 25 carbon atoms in the fatty acid. Specifically, a fatty acid ester nonionic surfactant of sorbitan described in U.S. Pat. No. 3,676,141 is preferred.

The reactant for forming the polymer material constituting the capsule wall is added inside the oil droplet and / or outside the oil droplet. Specific examples of the polymer substance include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, and melamine resin.

Two or more polymer substances can be used in combination as the capsule wall material. Preferred polymeric substances are polyurethanes, polyureas, polyamides, polyesters, polycarbonates, more preferably polyurethanes and polyureas. In the case of polyurethane and polyurea, tolylene diisocyanate trimethanol propane adduct, tolylene diisocyanate isocyanurate, xylylene diisocyanate trimethanol propane adduct, xylylene diisocyanate isocyanurate, hydrogenated xylylene diisocyanate isocyanate It is preferred to use a nullate form. For example, when using polyurea as a capsule wall material,
Diisocyanates, triisocyanates, tetraisocyanates, polyisocyanates such as polyisocyanate prepolymers, diamines, triamines, polyamines such as tetraamines, prepolymers containing two or more amino groups, piperazine or its derivatives or polyols Are reacted in an aqueous solvent by an interfacial polymerization method, whereby the microcapsule wall can be easily formed. In addition, for example, a composite wall made of polyurea and polyamide or a composite wall made of polyurethane and polyamide is heated using, for example, a polyisocyanate and an acid chloride or a polyamine and a polyol after adjusting the pH of an emulsifying medium to be a reaction liquid. Can be prepared. For details of the method for producing a composite wall composed of these polyurea and polyamide, see JP-A-58-669.
No. 48 publication.

Here, the preparation of microcapsules using a diazo compound as a color-forming component has been described. However, in the case of using the heat-sensitive recording material of the present invention, other color-forming components are included in the heat-responsive microcapsules. Microcapsules can be prepared in a similar manner.

In order to swell the microcapsule wall when heating the thermoresponsive microcapsules, a solid sensitizer may be added to the coating solution for the thermosensitive recording layer. As the solid sensitizer, those having a melting point of 50 ° C. or more, preferably 120 ° C. or less and being solid at room temperature can be selected and used from among the so-called polymer plasticizers used as the microcapsule walls. For example, when the wall material is made of polyurea or polyurethane, a hydroxy compound, a carbamate compound, an aromatic alkoxy compound, an organic sulfonamide compound, an aliphatic amide compound, an arylamide compound, or the like is preferably used. Specific examples of the water-soluble polymer include gelatin, polyvinyl alcohol,
Modified polyvinyl alcohol, methyl cellulose, polystyrene sodium sulfonate, ethylene / maleic acid copolymer are exemplified. As the physical properties of these polymer substances, a polymer substance that does not melt at the temperature during thermal recording and has a melting point of 150 ° C. or higher is preferable.

The heat-responsive microcapsules enclosing the color-forming component used in the present invention are obtained by dissolving a diazo compound in a low-boiling nonaqueous solvent together with a monomer for forming a capsule wall, and then distilling off the solvent during polymerization reaction. Can be microcapsules containing substantially no solvent. The polymer forming the microcapsule wall can be obtained by polymerizing the corresponding monomer by the above-described method, and the amount of the monomer used is such that the average particle size of the obtained microcapsule is 0.2 to 12 μm. It is determined. When a plurality of thermosensitive recording layers are laminated and used as a multicolor thermosensitive recording material, the upper layer preferably has good transparency, and from this viewpoint, the average particle size is in the range of 0.2 to 2 μm. Is preferred. By enclosing one of the coloring components in the microcapsules thus produced, the contact between the diazo compound and the coupling component at room temperature is prevented more than ever, and the storage stability is improved. In particular, a remarkable effect can be obtained by encapsulating the above-mentioned diazo compound, which is known as a coloring component having a problem in stability while having a higher coloring property than before, in the microcapsule according to the present invention.

In a heat-sensitive recording layer containing a diazo compound as a color-forming component, components not included in the two types of microcapsules, for example, a heat sensitizer and other color-forming aids,
The stabilizer and the like may be used by solid dispersion with a water-soluble polymer by a sand mill or the like. Preferred water-soluble polymers include water-soluble polymers used for preparing microcapsules (for example, JP-A-59-19088).
No. 6). In this case, the solid dispersion components based on the water-soluble polymer solution are added so as to be 10 to 40% by weight, respectively. The size of the dispersed particles is more preferably 10 μm or less, and more preferably 2 μm or less from the viewpoint of transparency.
In order to form a substantially transparent recording layer, the above components are dissolved in a water-insoluble or insoluble organic solvent and then mixed with an aqueous phase containing a surfactant and a water-soluble polymer as a protective colloid. However, it is preferable to use it in the form of an emulsified dispersion.

Another preferred color-forming component used in the present invention is a combination of an electron-donating dye precursor as an electron-donating dye and a color developer. Examples of the electron-donating dye precursor include a triarylmethane compound, a diphenylmethane compound, a thiazine compound, a xanthene compound, and a spiropyran compound.In particular, the triarylmethane compound and the xanthene compound have a high coloring density. Useful. An example of some of these is 3,3-bis (p-dimethylaminophenyl)-
6-dimethylaminophthalide (ie, crystal violet lactone), 3,3-bis (p-dimethylamino)
Phthalide, 3- (p-dimethylaminophenyl) -3-
(1,3-dimethylindol-3-yl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (o-methyl-p-diethylaminophenyl) -3- (2-methylindol-3-yl) phthalide , 4,4'-bis (dimethylamino) benzhydrin benzyl ether, N-halophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, rhodamine-B-anilinolactam, rhodamine (p -Nitroanilino) lactam, rhodamine-B- (p-chloroanilino) lactam, 2-benzylamino-6-diethylaminofluoran, 2-anilino-6-diethylaminofluoran, 2
-Anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-cyclohexylmethylaminofluoran, 2-anilino-3-methyl-6
-Isoamylethylaminofluoran, 2- (o-chloroanilino) -6-diethylaminofluoran, 2-octylamino-6-diethylaminofluoran, 2-ethoxyethylamino-3-chloro-2-diethylaminofluoran, 2- Anilino-3-chloro-6-diethylaminofluoran, benzoylleucomethylene blue,
p-Nitrobenzyl leucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-dichloro-spiro-dinaphthopyran, 3-benzylspirodinaphthopyran, 3-propyl-spiro-dibenzopyran And the like.

Examples of the electron accepting compound which is a developer for the electron donating dye precursor include phenol derivatives, salicylic acid derivatives, and hydroxybenzoic acid esters. Particularly, bisphenols and hydroxybenzoates are preferred. To illustrate some of these,
2,2-bis (p-hydroxyphenyl) propane (that is, bisphenol A), 4,4 ′-(p-phenylenediisopropylidene) diphenol (that is, bisphenol P), 2,2-bis (p-hydroxy Phenyl) pentane, 2,2-bis (p-hydroxyphenyl) ethane, 2,2-bis (p-hydroxyphenyl) butane,
2,2-bis (4′-hydroxy-3 ′, 5′-dichlorophenyl) propane, 1,1- (p-hydroxyphenyl) cyclohexane, 1,1- (p-hydroxyphenyl) propane, 1,1- ( p-hydroxyphenyl)
Pentane, 1,1- (p-hydroxyphenyl) -2-
Ethylhexane, 3,5-di (α-methylbenzyl) salicylic acid and its polyvalent metal salt, 3,5-di (tert
-Butyl) salicylic acid and its polyvalent metal salts, 3-α,
α-dimethylbenzylsalicylic acid and its polyvalent metal salts, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, 2-ethylhexyl p-hydroxybenzoate, p-phenylphenol, p-cumylphenol and the like. .

In the case of using a heat-sensitive recording layer containing an electron-donating dye precursor and an electron-accepting compound as a color developer in the multicolor heat-sensitive recording material of the present invention, the electron-donating dye precursor and the color developer Is required to be encapsulated in a microcapsule produced in the presence of a surfactant polymer containing at least 5 mol% of the unit represented by the general formula (I). These color-forming components can be microencapsulated using the methods described above for diazo compounds. In the heat-sensitive recording material of the present invention, in addition to the above-described components, to increase the color density at the time of heat recording, or to lower the minimum color-forming temperature,
Other additives can be added as long as the object of the present invention is not impaired. As this additive, to reduce the melting point of the coupler, basic substance, or diazo compound, or to lower the softening point of the capsule wall, the diazo compound, the basic substance, and the coupler are easily reacted to create a situation. belongs to.

Examples of additives for improving color development include phenol compounds, alcoholic compounds, amide compounds, sulfonamide compounds, and the like.
tert-octylphenol, p-benzyloxyphenol, phenyl p-oxybenzoate, benzyl carbanilate, phenethyl carbanilate, hydroquinone dihydroxyethyl ether, xylylene diol, N-hydroxyethyl-methanesulfonic acid amide, N-phenyl-methanesulfone Acid amide, benzyl p-benzyloxybenzoate, α-naphthylbenzyl ether, β-naphthylbenzyl ether, β-naphthoic acid phenyl ester, α-hydroxy-β-naphthoic acid phenyl ester, β-naphthol- (p-chlorobenzyl ) Ether, 1,4-butanediol phenyl ether, 1,4
-Butanediol-p-methylphenyl ether, 1,
4-butanediol-p-ethylphenyl ether,
1,4-butanediol-m-methylphenyl ether, 1-phenoxy-2- (p-tolyloxy) ethane, 1-phenoxy-2- (p-ethylphenoxy) ethane, 1-phenoxy-2- (p-chloro Phenoxy)
Ethane, p-benzylbiphenyl and the like. These may be contained in the core substance or may be added to the microcapsule dispersion as an emulsified dispersion.

In the present invention, the above-mentioned diazonium salt compound, a coupler, a basic substance, and a colorless electron-donating dye, an electron-accepting compound and a color-improving agent which react with the diazonium salt compound to give a color when heated. The use form of the additive is not particularly limited. (1) a method of using a solid dispersion, (2) a method of using an emulsified dispersion, (3) a method of using a polymer, and (4) a method of using a latex. As described above, one of the coloring components is used by being encapsulated in a microcapsule obtained by a specific manufacturing method.

In the present invention, the above-mentioned heat-sensitive recording layers may be laminated, and a multi-color heat-sensitive recording material can be obtained by changing the hue of each heat-sensitive recording layer. Although the layer configuration is not particularly limited, it is particularly preferable that the layers having different photosensitive wavelengths have different wavelengths.
Thermal recording using two types of diazonium salt compounds, two thermosensitive recording layers combining couplers that react with each diazonium salt compound when heated to develop different colors, and a thermosensitive recording layer combining an electron-donating colorless dye and an electron-accepting compound. A multicolor heat-sensitive recording material in which layers are laminated is preferred. That is, a thermosensitive recording layer A containing an electron-donating colorless dye and an electron-accepting compound on a support, a diazonium salt compound having a maximum absorption wavelength of 360 ± 20 nm, and a coupler which reacts with the diazonium salt compound when heated to give a color. And a thermosensitive recording layer B-2 containing a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm and a coupler which reacts with the diazonium salt compound when heated to form a color. is there. In this example, a full-color image can be recorded by selecting the coloring hues of the respective heat-sensitive recording layers so as to be three primary colors, yellow, magenta, and cyan in the subtractive color mixing.

In particular, from the viewpoint of quickness and stability of light fixing property, in the case of the above-described full-color recordable multicolor heat-sensitive recording material, a diazo compound is encapsulated in a thermoresponsive microcapsule in the uppermost layer, and a coupler is formed. Alternatively, it is preferable to arrange a thermosensitive recording layer in which a basic substance is encapsulated in microcapsules of an alkali-soluble polymer. When the present invention is used for a multicolor heat-sensitive recording material, the other color-forming component not encapsulated in the microcapsules may be encapsulated in the alkali-soluble microcapsules as described above, or may be solid-dispersed. From the viewpoint of improving the image quality of a multi-color image by providing a transparent thermosensitive coloring layer, a solution is dissolved in an organic solvent which is hardly soluble or insoluble in water, and then this is dissolved in a surfactant and / or a water-soluble polymer. It is preferable to mix with an aqueous phase having a protective colloid to obtain an emulsified dispersion. From the viewpoint of facilitating emulsification and dispersion, it is preferable to use a surfactant. The organic solvent used in this case can be appropriately selected from, for example, high boiling oils described in JP-A-2-141279. Of these, the use of esters is preferable from the viewpoint of the emulsification stability of the emulsified dispersion, and particularly, when tricresyl phosphate is used alone or in combination, the emulsification and dispersion stability of the developer is particularly good. Yes and preferred. The above oils can be used together or with other oils. An auxiliary solvent can be further added to the above organic solvent as a dissolving and removing agent having a low boiling point. As such co-solvents, for example, ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride and the like can be mentioned as particularly preferable ones. In some cases,
It is also possible to use only a low-boiling auxiliary solvent without a high-boiling oil.

The water-soluble polymer to be contained as a protective colloid in the aqueous phase mixed with the oil phase containing these coloring components is appropriately selected from known anionic polymers, nonionic polymers and amphoteric polymers. can do. Preferred water-soluble polymers include, for example, polyvinyl alcohol,
Gelatin, cellulose derivatives and the like can be mentioned.
Further, as the surfactant to be contained in the aqueous phase, a surfactant which does not cause precipitation or aggregation by acting on the protective colloid can be appropriately selected from anionic or nonionic surfactants. Preferred surfactants include
Examples thereof include sodium alkylbenzene sulfonate, sodium alkyl sulfate, dioctyl sodium sulfosuccinate, and polyalkylene glycol (for example, polyoxyethylene nonyl phenyl ether). The emulsified dispersion used for the multicolor heat-sensitive recording material in the present invention is:
By mixing and dispersing the oil phase containing the above components and the aqueous phase containing the protective colloid and the surfactant using high-speed stirring, ultrasonic dispersion, or the like, a means used for ordinary fine particle emulsification, etc. Obtainable. The ratio of the oil phase to the aqueous phase (oil phase weight / water phase weight) is 0.02 to 0.02.
0.6 is preferred, and particularly preferably 0.1 to 0.4. If it is less than 0.02, the aqueous phase is too large to be diluted, so that sufficient coloring property cannot be obtained. If it is more than 0.6, the viscosity at night becomes high, which causes inconvenient handling and lowers the stability of the coating solution.

In the heat-sensitive recording material of the present invention, a binder is used for the heat-sensitive recording layer to fix various materials such as a coloring material on a support or on the already applied heat-sensitive recording layer or intermediate layer. Is preferred. Examples of the binder include gelatin, polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, arabic gum, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylate, and ethylene-vinyl acetate. Examples include various emulsions such as polymers.
The amount of the binder used is 0.5 to 5 g /
m ² is preferable. In the heat-sensitive recording material of the present invention, citric acid, tartaric acid, oxalic acid as an acid stabilizer,
Boric acid, phosphoric acid, pyrophosphoric acid and the like can be used. In the heat-sensitive recording material of the present invention, it is preferable to provide a protective layer on the heat-sensitive recording layer. When the protective layer is provided on the uppermost layer of the heat-sensitive recording layer, the mechanical strength of the surface of the heat-sensitive recording layer can be improved.

Pigments, metal soaps, waxes, crosslinking agents, and the like are added to the protective layer for the purpose of improving the matching property of the thermal head during thermal recording and improving the water resistance of the protective layer. Details of these pigments, metal soaps, waxes, crosslinking agents and the like are described in, for example, JP-A-2-141279. In order to uniformly form a protective layer on the heat-sensitive recording layer, a surfactant is added to the coating liquid for forming a protective layer. Examples of the surfactant include a sulfosuccinic acid-based alkali metal salt, a fluorine-containing surfactant and the like. Specifically, di- (2-ethylhexyl) sulfosuccinic acid, di-
There are sodium salts or ammonium salts such as (n-hexyl) sulfosuccinic acid. Further, in the protective layer, a surfactant for preventing electrification of the manufactured heat-sensitive recording material,
A polymer electrolyte or the like may be added. The coating amount of the solid content of the protective layer is usually 0.2 to 5 g / m ² , preferably 1 g to 3 g / m ² .
Preferably, it is manufactured to have m ² .

When a plurality of heat-sensitive recording layers are provided as a multicolor heat-sensitive recording material in the heat-sensitive recording material of the present invention, an intermediate layer is provided between the heat-sensitive recording layers in order to further improve the thermal separation of each layer. It is preferred to provide a layer. As the material of the intermediate layer to be used, an emulsion or latex of a water-soluble polymer or a hydrophobic polymer is preferable. As the water-soluble polymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, styrene-maleic anhydride copolymer and its ester, butadiene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, Isobutylene-maleic anhydride copolymer, polyacrylamide, polystyrenesulfonic acid, polyvinylpyrrolidone, ethylene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer, oxidized starch, phosphorylated starch, gelatin, carboxymethylcellulose, methylcellulose, Examples include sodium alginate, sulfated cellulose, and hydroxyethyl cellulose. Examples of the hydrophobic polymer emulsion or latex include a styrene-butadiene copolymer, a carboxy-modified styrene-butadiene copolymer, and an acrylonitrile-butadiene copolymer.

As a recording method of the multicolor heat-sensitive recording material thus obtained, in the case of a full-color structure, first, the heat-sensitive recording layer B-2 disposed as the uppermost heat-sensitive recording layer is heated and included in the layer. The diazonium salt compound and the coupler are colored. Next, after irradiating light of 400 ± 20 nm to decompose the unreacted diazonium salt compound contained in the thermosensitive recording layer B-2, sufficient heat is applied to the thermosensitive recording layer B-1 to develop color. The diazonium salt compound and the coupler contained in the layer are colored. At this time, the heat-sensitive recording layer B-2 is also strongly heated, but does not develop color because the diazonium salt compound has already been decomposed and the color-forming ability has been lost. Further, by irradiating light of 360 ± 20 nm, the diazonium salt compound contained in the heat-sensitive recording layer B-1 is decomposed, and finally, sufficient heat for the heat-sensitive recording layer A to develop color is applied to develop the color. At this time, the heat-sensitive recording layers B-2 and B-1 are also strongly heated at the same time, but do not develop color because the diazonium salt compound has already been decomposed and the coloring ability has been lost.

In the heat-sensitive recording material of the present invention, a light transmittance adjusting layer can be provided. The light transmittance adjusting layer contains a component that functions as a precursor of an ultraviolet absorber, and does not function as an ultraviolet absorber before irradiation with light having a wavelength in a region necessary for fixing. When the fixing type thermosensitive recording layer is fixed, the wavelength in the region required for fixing is sufficiently transmitted, and the transmittance of visible light is high, so that there is no trouble in fixing the thermosensitive recording layer. The precursor of the ultraviolet absorber functions as an ultraviolet absorber by reacting with light or heat after light irradiation of a wavelength necessary for fixing of the light fixing type thermosensitive recording layer by light irradiation is completed. Most of the light in the wavelength range necessary for fixing in the ultraviolet region is absorbed by the ultraviolet absorber, the transmittance is reduced, and the light resistance of the heat-sensitive recording material is improved. There is no substantial change in the transmittance of visible light. At least one light transmittance adjusting layer can be provided in the light fixing type thermosensitive recording material, and most preferably, it is formed between the light fixing type thermosensitive recording layer and the protective layer. May also be used as the protective layer.

The characteristics of the light transmittance adjusting layer can be arbitrarily selected according to the characteristics of the light fixing type thermosensitive recording layer. Particularly, a heat-sensitive recording material that is effective for applying a light transmittance adjusting layer contains, on a support, a diazonium salt compound having a maximum absorption wavelength of 360 ± 20 nm and a coupler that reacts with the diazonium salt compound to form a color. A light-fixing type thermosensitive recording layer, and a light-fixing type thermosensitive recording layer containing a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm and a coupler which reacts with the diazonium salt compound and forms a color, are sequentially provided.
It is desirable to provide a light transmittance adjusting layer on this layer. In the case of such a heat-sensitive recording material, the light transmittance of the light transmittance adjusting layer in the wavelength region where light is fixed is 65% or more at 360 nm, and the light transmittance after fixing is 20% at 360 nm.
It is desirable that: In this case, light irradiation means a wavelength of 420 nm using a xenon lamp forced tester.
It means that light irradiation of 13 kJ / m ² is performed. Specifically, the Weather Meter Ci65 (Atl
as Electric Co. Light irradiation at 0.9 W / m ² for 4.0 hours. A photo-fixing type thermosensitive recording layer containing a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm and a coupler which reacts with the diazonium salt compound to form a color;
A heat-sensitive recording material may be provided in which a light-fixing type heat-sensitive recording layer containing a diazonium salt compound having a thickness of 20 nm and a coupler that reacts with the diazonium salt compound to form a color is sequentially provided.

Further, according to the present invention, the maximum absorption wavelength is 340n.
m, a photo-fixing type thermosensitive recording layer containing a diazonium salt compound and a coupler that reacts with the diazonium salt compound to form a color, and reacts with the diazonium salt compound having a maximum absorption wavelength exceeding 420 nm and the diazonium salt compound to form a color. And a light-fixing type heat-sensitive recording layer containing a coupler. By changing the hue of each heat-sensitive recording layer in the heat-sensitive recording layer, a multi-color heat-sensitive recording material can be obtained. That is, a full-color image can be recorded by selecting the coloring hues of the respective heat-sensitive recording layers so as to be three primary colors, yellow, magenta, and cyan in the subtractive color mixing. In this case, the coloring mechanism of the heat-sensitive recording layer directly laminated on the support surface (the lowermost layer of the heat-sensitive recording layer) is not limited to the combination of the electron-donating dye and the electron-accepting dye. Any of a diazo coloring system, a base coloring system that forms a color by contacting with a basic compound, a chelating coloring system, and a coloring system that reacts with a nucleophile to cause a desorption reaction to form a color from a coupler that reacts with a diazonium salt to form a color. Alternatively, two heat-fixable heat-sensitive recording layers each containing a diazonium salt compound having a different maximum absorption wavelength and a coupler that reacts with the diazonium salt compound to form a color may be provided on the heat-sensitive recording layer. It is desirable to sequentially provide a transmittance adjusting layer and a protective layer.
As the compound used for the light transmittance adjusting layer, for example,
JP-A-9-1928 can be mentioned.

In the present invention, the following known antioxidants can be used to further improve the light fastness. For example, EP-A-310551,
German Patent No. 3435443, European Patent No. 310552, Japanese Patent Application Laid-Open No. 3-121449.
JP-A-59-41616, JP-A-2-262654, JP-A-2-71262, JP-A-63-163351, U.S. Pat. No. 4,814,262, and JP-A-54-48535. ,
JP-A-5-61166, JP-A-5-119449
No., US Pat. No. 4,980,275, JP-A-63
JP-A-113536, JP-A-62-262047, EP-A-223239, EP-A-309402, and EP-A-309401.
Specifically, the following are mentioned.

[0075]

Embedded image

[0076]

Embedded image

[0077]

Embedded image

It is also effective to use various additives already known as heat-sensitive recording materials. Some of these antioxidants are described in JP-A-60-125470, JP-A-60-125471 and JP-A-60-1.
No. 25472, JP-A-60-287485,
JP-A-60-287486, JP-A-60-287
487, JP-A-62-146680, JP-A-60-287488, and JP-A-62-228288.
No. 5, JP-A-63-89877, JP-A-63-89877
-88380, JP-A-63-088381, JP-A-01-239282, JP-A-04-2
No. 91885, Japanese Patent Application Laid-Open No. 04-291684,
JP-A-05-188687, JP-A-05-188
686, JP-A-05-110490, JP-A-05-110837, JP-A-05-1703
No. 61, JP-A-63-203372, JP-A-63-224989, JP-A-63-267594
JP, JP-A-63-182484 and JP-A-60-182
JP-A-107384, JP-A-60-107383, JP-A-61-160287, JP-A-61-1
No. 85483, JP-A-61-211079,
JP-A-63-251282, JP-A-63-051
No. 174, JP-B-48-043294, JP-B-48-033212 and the like.

Specific examples include 6-ethoxy-1-phenyl-
2,2,4-trimethyl-1,2-dihydroquinoline,
6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,
2,4-trimethyl-1,2,3,4-tetrahydroquinoline, nickel cyclohexanoate, 2,2-bis-4
-Hydroxyphenylpropane, 1,1-bis-4-hydroxyphenyl-2-ethylhexane, 2-methyl-
Examples include 4-methoxy-diphenylamine, 1-methyl-2-phenylindole and the compounds shown below.

[0080]

Embedded image

[0081]

Embedded image

[0082]

Embedded image

[0083]

Embedded image

These antioxidants can be added to the heat-sensitive recording layer or the intermediate layer, the light transmittance adjusting layer, and the protective layer. When these antioxidants are used in combination, for example, specific examples (Q-7), (Q-45), (Q-4)
6) or a combination of compound (Q-10) and compound (Q-13).

As the support in the present invention, a plastic film, paper, plastic resin laminated paper, synthetic paper, or the like can be used.

In the method for producing a heat-sensitive recording material of the present invention, when a heat-sensitive recording layer is provided on the support, a substantially colorless color-forming component A and a substantially colorless color-forming component which reacts with the color-forming component A to form a color. Producing a microcapsule containing at least one of the color-forming components B in the presence of at least one surfactant polymer containing at least 5 mol% of the unit represented by the general formula (I); Coloring component A
Or a microcapsule containing either one of the color-forming components B and a step of preparing a heat-sensitive recording layer coating solution containing the other color-forming component.The details of these preparation methods are as follows. As described in the examples. Here, the prepared heat-sensitive recording material layer coating solution is applied on the support to form a heat-sensitive recording layer, but this does not necessarily mean that the heat-sensitive recording layer is directly provided on the support. To improve interlayer adhesion, an undercoat layer may be provided on the support, and a heat-sensitive recording layer may be provided thereon. Further, a plurality of thermosensitive recording layers may be provided according to the purpose, and further, an intermediate layer may be provided between the plurality of thermosensitive recording layers, or a light transmittance adjusting layer and a protective layer may be provided. A known method can be applied. The heat-sensitive recording layer containing the color-forming component encapsulated in the thermoresponsive microcapsules produced in the presence of the surfactant polymer according to the present invention, if at least one layer is provided on the support, the effect of the present invention can be obtained. However, when a plurality of heat-sensitive recording layers are provided, it is preferable that all of the heat-sensitive recording layers contain a color-forming component encapsulated in the thermoresponsive microcapsules.

[0087]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. (Example 1) (Preparation of capsule liquid (A)) 4.5 g of the surfactant polymer (A) according to the present invention represented by the following structural formula (A) was dissolved in 36 g of ethyl acetate at 60 ° C.

[0088]

Embedded image

Further, 19.0 g of a compound represented by the following structural formula (1) was added to this ethyl acetate solution, and the following structural formula (2)
4.2 g of the compound represented by the following formula, 7.4 g of the compound represented by the following structural formula (3), 0.6 g of the compound represented by the following structural formula (4), and 1.9 g of the compound represented by the following structural formula (5)
Then, 0.8 g of the compound represented by the following structural formula (6) was added, and the mixture was heated and dissolved at 70 ° C., and then cooled to 35 ° C.

[0090]

Embedded image

[0091]

Embedded image

[0092]

Embedded image

Then, 0.8 g of n-butanol, 11.2 g of capsule wall material Takenate D119N (trade name: manufactured by Takeda Pharmaceutical Co., Ltd.), and capsule wall material Takenate D110
4.1 g of N (manufactured by Takeda Pharmaceutical Co., Ltd.) and 10.5 g of Sumidur N3200 (trade name, manufactured by Sumitomo Bayer Urethane Co., Ltd.) were added, and the mixture was kept at 35 ° C. for 40 minutes.
The obtained solution was mixed with 100 g of water, and then 10,000 r using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).
Emulsification was performed at pm. After further adding 40 g of water and 1.0 g of tetraethylenepentamine to the obtained emulsion, an encapsulation reaction was carried out at 50 ° C. for 3 hours to obtain a capsule solution having an average particle diameter of 0.7 μm and a solid content of 43%. It was adjusted. In addition, the value of the 50% volume average particle diameter measured using a laser diffraction particle size distribution analyzer (LA700) manufactured by Horiba, Ltd. was used for all the average particle diameters.

(Preparation of Capsule Solution (B)) The surfactant polymer (A) of the present invention represented by the following structural formula (A)
4.5 g was dissolved in 36 g of ethyl acetate at 60 ° C.

[0095]

Embedded image

Further, 19.0 g of the compound represented by the structural formula (1), 4.2 g of the compound represented by the structural formula (2), 7.4 g of the compound represented by the structural formula (3) were added to this ethyl acetate solution. 0.6 g of the compound represented by Structural Formula (4), 1.9 g of the compound represented by Structural Formula (5) and 0.8 g of the compound represented by Structural Formula (6) are added to 36 g of ethyl acetate. After heating and dissolving, the mixture was cooled to 30 ° C.

15.0 g of Takenate D110N (manufactured by Takeda Industry Co., Ltd.), capsule wall agent: Vernock D750 (product name: manufactured by Dainippon Ink Co., Ltd.) 10.4
g was added and kept warm at 35 ° C. for 5 minutes. The resulting solution is diluted with water 1
After mixing to 00 g, the mixture was emulsified at 10,000 rpm using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). After further adding 40 g of water and 1.0 g of tetraethylenepentamine to the obtained emulsion, an encapsulation reaction was carried out at 50 ° C. for 3 hours to obtain a high-concentration capsule having an average particle diameter of 0.7 μm and a solid content of 43%. The liquid was adjusted.

(Preparation of Emulsion Dispersion of Electron-Accepting Compound)
3.4 g of the compound represented by the following structural formula (13), 8.3 g of the compound represented by the following structural formula (14), 8.3 g of the compound represented by the following structural formula (15), and the following structural formula (1)
5.8 g of the compound represented by the following formula (6), 3.9 g of the compound represented by the following structural formula (17), 3.5 g of the compound represented by the following structural formula (18), and 0.1 g of tricresyl phosphate.
8 g, diethyl maleate 0.4 g and ethyl acetate 15 g
And dissolved at 70 ° C.

[0099]

Embedded image

[0100]

Embedded image

The obtained solution was treated with a 15% by weight aqueous solution of polyvinyl alcohol (PVA205C manufactured by Kuraray Co., Ltd.).
0 g, 9 g of a 2.0% by weight aqueous solution of sodium dodecylbenzenesulfonate and 9 g of a 2% by weight aqueous solution of a compound represented by the following structural formula (19) were added to an aqueous phase, followed by ace homogenizer (Nippon Seiki Co., Ltd.) Was emulsified at 10,000 rpm for 3 minutes. The particle size obtained was 0.5 μm.

[0102]

Embedded image

(Preparation of Pigment Dispersion for Protective Layer) 20 g of kaolin (Mizusawa Chemical Kao Gloss) was added to 90 g of water and stirred for 3 hours. Dispersant (Poise 532A:
0.5 g of 10% polyvinyl alcohol aqueous solution (PVA105: manufactured by Kuraray), 10 g of 30% by weight zinc stearate dispersion (Z-7-30: manufactured by Chukyo Yushi Co., Ltd.), 10 g, 10% dodecylbenzene 0.5 g of an aqueous solution of sodium sulfonate was added, and dispersed by a ball mill to obtain an average particle size of 0.8 μm.

(Preparation of Protective Layer Solution) 50 g of water, 50 g of a 6% by weight aqueous solution of methylcellulose (Metroze SM-15, softening temperature 210 ° C., manufactured by Shin-Etsu Chemical Co., Ltd.), and a 20.5% by weight zinc stearate dispersion (F155: Chukyo) Oil and fat) 0.
5 g, 1.0% boric acid aqueous solution 25 g, kaolin dispersion 7 g, 4% fluoropolymer aqueous dispersion (ME413: manufactured by Daikin Industries, Ltd.) 0.5 g, 10% sodium dodecylbenzenesulfonate aqueous solution 1 g and the following structural formula ( 15 g of a 2% by weight aqueous solution of the compound represented by 20) and 1.0 g of a 40% aqueous glyoxal solution were mixed to obtain a protective solution.

[0105]

Embedded image

Preparation of BC Layer Coating Solution 1 Kg of lime-treated gelatin, 757 g of a gelatin dispersion containing 12 wt% of a spherical PMMA matting agent having an average particle diameter of 5.7 μm, a compound represented by the following structural formula (21) to a compound represented by the following structural formula 3,761 g of an emulsion of an ultraviolet absorber containing the compound represented by (26) at the following content (the content of the ultraviolet absorber per 1 kg of the emulsion is determined by the structural formula of the ultraviolet absorber (2)
1) 9.8 g, Structural Formula (22) 8.4 g, Structural Formula (23) 9.8 g, Structural Formula (24) 13.9 g, Structural Formula (25) 29.3 g), 1, 2 1.75 g of benzisothiazolin-3-one and 64.000 of poly (sodium p-vinylpentenesulfonate) (molecular weight: about 400,000).
2 g of a compound represented by the following structural formula (26)
g, 3,180 ml of a 20% solution of a latex of polyethyl acrylate, 75.0 g of N, N'-ethylene-bis (vinylsulfonylacetamide), and 25.0 of 1,3-bis (vinylsulfonylacetamide) propane.
g, and water was added thereto to prepare a total amount of 62.77 liters.

[0107]

Embedded image

[0108]

Embedded image

The BPC layer coating solution was prepared by the following method. 1 kg of lime-processed gelatin, average particle size 0.70
2,000 g of a gelatin dispersion containing 15 wt% of a μm spherical PMMA matting agent, 1,268 ml of methanol,
1,75-benzisothiazolin-3-one
g, sodium polyacrylate (molecular weight about 100,000)
4.4 g, 54.0 g of poly (sodium p-vinylbenzenesulfonate) (molecular weight: about 400,000), 25.2 g of sodium pt-octylphenoxypolyoxyethylene-ethylsulfonate, N-propyl-N- 5.3 g of sodium polyoxyethylene-perfluorooctanesulfonamidobutylsulfonate, 7.1 g of potassium perfluorooctanesulfonate, p with caustic soda
After adjusting to H = 7.0, water was added to bring the total amount to 66.79.
Liters.

(Preparation of Transparent Support) A 175 μm-thick
SBR latex is dry-coated on one surface of a blue polyethylene terephthalate (PET) film colored at x = 0.2850, y = 0.29995 on the chromaticity coordinates specified by the method described in JIS-Z8701. It was applied so that the amount was 0.3 g / m ² . 200 g of a 5% by weight aqueous gelatin solution (Nitta Gelatin # 810)
0.5 g of a 5% by weight polymethyl methacrylate resin particle gelatin dispersion having a particle diameter of 2 μm (polymethyl methacrylate resin content: 10% by weight), 3% by weight 1,2-benzothiazolin-3-one aqueous solution 1.0 g A coating liquid obtained by mixing 10 g of a 2% by weight aqueous solution of di (2-ethyl) hexyl sulfosuccinate was applied so that the dry coating amount was 0.1 g / m ² . Subsequently, the other surface was coated in the same manner.

(Preparation of Thermosensitive Recording Material) A BC was applied to one surface of the above-mentioned double-sided undercoated support from the side close to the support.
Solution and BPC solution in the order of 44.0 ml / m
² , and applied and dried at 18.5 ml / m ² .

Next, the capsule liquid (A) (solid content: 43%) was coated on the surface opposite to the surface on which the BC layer and the BPC layer were provided.
2.4 g, the capsule liquid (B) (solid content concentration 43%)
5.7 g, 40 g of the electron-accepting compound emulsion dispersion (solid content: 21% by weight), 1.25 g of 20% by weight colloidal silica (Nissan Chemical Snowtex O), and a compound represented by the following structural formula (27) 50% by weight aqueous solution 0.4
9 g were mixed and applied and dried so that the dry weight became 13.1 g / m ² . Subsequently, the protective layer coating solution was dried on the coating layer so that the dry weight became 2.5 g / m ² , to obtain a heat-sensitive recording material according to the present invention.

[0113]

Embedded image

Comparative Example 1 Preparation of Capsule Solution (C) 19.0 g of the compound represented by the structural formula (1), 4.2 g of the compound represented by the structural formula (2), and 7.4 g of the compound represented by the formula, 0.6 g of the compound represented by the structural formula (4), 1.9 g of the compound represented by the structural formula (5) and 0.8 g of the compound represented by the structural formula (12) were converted into 36 g of ethyl acetate. The mixture was added, heated to 70 ° C. and dissolved, and then cooled to 35 ° C. 0.8 g of n-butanol, capsule wall material: Takenate D119N
(Takeda Pharmaceutical Co., Ltd.) 11.2 g, Takenate D
10. 110 N (manufactured by Takeda Pharmaceutical Co., Ltd.) 4.1 g;
5 g was added, and the mixture was kept at 35 ° C. for 40 minutes. The resulting solution is 8
% Polyvinyl alcohol aqueous solution (PVA217)
E: manufactured by Kuraray Co., Ltd.) and mixed with an aqueous phase obtained by mixing 75 g of water and 26 g of water, and then emulsified at 10,000 rpm using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).
After further adding 140 g of water and 1.0 g of tetraethylenepentamine to the obtained emulsion, an encapsulation reaction was carried out at 50 ° C. for 3 hours to give a capsule solution having an average particle size of 0.7 μm and a solid concentration of 27%. Prepared. In addition, the value of the 50% volume average particle diameter measured using a laser diffraction particle size distribution analyzer (LA700) manufactured by Horiba, Ltd. was used for all the average particle diameters. In addition, when the amount of water added to the emulsion was set to 40 g, which is the same as in Example 1, in order to increase the concentration, encapsulation reaction aggregation occurred and a desired capsule liquid could not be obtained.

(Preparation of Capsule Solution (D)) 19.0 g of the compound represented by the structural formula (1), 4.2 g of the compound represented by the structural formula (2), and compound 7 represented by the structural formula (3). 4 g, 0.6 g of the compound represented by Structural Formula (4), 1.9 g of the compound represented by Structural Formula (5), and
0.8 g of the compound represented by 2) was added to 36 g of ethyl acetate, heated to 70 ° C, dissolved, and then cooled to 30 ° C. To this, 15.0 g of capsule wall material: Takenate D110N (manufactured by Takeda Pharmaceutical Co., Ltd.) and 10.4 g of Vernock D750 (manufactured by Dainippon Ink Co., Ltd.) were added, and the mixture was kept at 35 ° C. for 5 minutes. The obtained solution is treated with an 8% by weight aqueous solution of polyvinyl alcohol (PVA217E: manufactured by Kuraray Co., Ltd.) 75
g and 26 g of water, and then mixed with an aqueous phase using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).
Emulsification was performed at rpm. Add 140 more to the obtained emulsion.
g of water and 1.0 g of tetraethylenepentamine were added, and an encapsulation reaction was performed at 50 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 0.7 μm and a solid content concentration of 27%. In addition, the value of the 50% volume average particle diameter measured using a laser diffraction particle size distribution analyzer (LA700) manufactured by Horiba, Ltd. was used for all the average particle diameters. In order to increase the concentration, the amount of water added to the emulsion was set to 40
In the case of g, aggregation occurred during the capsule reaction, and the desired capsule liquid could not be obtained.

(Preparation of Thermosensitive Recording Material) As in Example 1, the amount of the BC solution and the amount of the BPC solution applied to one surface of the double-sided undercoated support in the order of BC solution and BPC solution were 44 It was applied so as to be 0.01 ml / m ² and 18.5 ml / m ² and dried. Next, the capsule liquid (C) (solid concentration 27%) was coated on the surface opposite to the side where the BC layer and the BPC layer were provided.
%), 4.2 g of the capsule liquid (D) (solid concentration 27
%) 10.0 g, the above-mentioned electron-accepting compound emulsion dispersion (solid content concentration 21% by weight) 40 g, 20% by weight colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.) 1.25
g and 0.4 g of a 50% by weight aqueous solution of the compound represented by the structural formula (27) are mixed, and the dry weight is 13.5 g / m 2.
^It was applied and dried to obtain ² . Subsequently, the coating liquid for the protective layer was dried on the coated material so that the dry weight became 2.5 g / m ² , to obtain a heat-sensitive recording material of Comparative Example 1.

(Example 2) (Preparation of capsule liquid (E)) 1.3 g of the surfactant polymer (A) according to the present invention represented by the following structural formula (A) was dissolved in 10 g of ethyl acetate at 60 ° C. .

[0118]

Embedded image

Further, in this ethyl acetate solution, 5.6 g of the compound represented by the structural formula (1), 1.5 g of the compound represented by the structural formula (3), 1.1 g of the compound represented by the following structural formula (28), 0.7 g of the compound represented by the following structural formula (29), 0.7 g of the compound represented by the following structural formula (30)
g, 0.1 g of the compound represented by the structural formula (4), and 0.2 g of the compound represented by the structural formula (6) were added and dissolved by heating. After cooling to 40 ° C., Takenate D127 was added.
N (manufactured by Takeda Pharmaceutical Co., Ltd.) 6.4 g, Takenate D
110N (manufactured by Takeda Pharmaceutical Co., Ltd.) 1.1 g and n
-Butanol 0.2g was added and stirred at 40 ° C for 40 minutes. After adding the obtained solution to 30.0 g of water,
Using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.)
The emulsification and dispersion were performed at 10,000 rpm.

[0120]

Embedded image

[0121]

Embedded image

The obtained emulsion was further mixed with 15.0 distilled water.
g, 0.4 g of tetraethylenepentamine,
The encapsulation reaction was performed at 60 ° C. for 4 hours to prepare a capsule liquid (E) having an average particle diameter of 0.6 μm and a solid concentration of 43%.

(Preparation of Capsule Liquid (F)) The surfactant polymer (A) of the present invention represented by the following structural formula (A)
1.3 g was dissolved in 10 g of ethyl acetate at 60 ° C.

[0124]

Embedded image

Further, in this ethyl acetate solution, 5.5 g of the compound represented by the structural formula (1), 2.7 g of the compound represented by the structural formula (3), 1.1 g of the compound represented by the structural formula (28), 0.7 g of a compound represented by the formula (29):
0.6 g of the compound represented by Structural Formula (30), 0.6 g of the compound represented by Structural Formula (4), and 0.3 g of the compound represented by Structural Formula (6) were dissolved in 11.1 g of ethyl acetate in 7 g.
After heating and dissolving at 0 ° C. and cooling to 45 ° C., 6.2 g of Takenate D-140 (manufactured by Takeda Pharmaceutical Co., Ltd.) and 1.1 g of Takenate D-750 (manufactured by Takeda Pharmaceutical Co., Ltd.) were added. After adding the obtained solution to 30.0 g of water,
Using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.)
The emulsification and dispersion were performed at 10,000 rpm.

After further adding 15 g of distilled water and 0.4 g of tetraethylenepentamine to the obtained emulsion, 6
The encapsulation reaction was performed at 0 ° C. for 3 hours to prepare a capsule liquid (F) having an average particle diameter of 0.6 μm and a solid concentration of 43%.

(Preparation of Emulsion Dispersion of Electron-Accepting Compound)
16.0 g of the compound represented by Structural Formula (14), 7.7 g of the compound represented by Structural Formula (15), and Structural Formula (17)
5.7 g of a compound represented by the formula, 4.1 g of a compound represented by the structural formula (18), 1.4 g of a compound represented by the following structural formula (31), and a compound 2.1 represented by the following structural formula (32)
g, 1.4 g of a compound represented by the following structural formula (33), 1.0 g of a compound represented by the following structural formula (34), 1.0 g of tricresyl phosphate, 0.6 g of diethyl maleate, and 18 g of ethyl acetate And dissolved.

[0128]

Embedded image

[0129]

Embedded image

The obtained solution was treated with a 5.0% by weight aqueous solution of polyvinyl alcohol (PVA-205 manufactured by Kuraray Co., Ltd.).
C) 140 g, 11.0 g of a 2.0% by weight aqueous solution of sodium dodecylbenzenesulfonate, and structural formula (1
After adding 11.0 g of a 2% by weight aqueous solution of the compound represented by the formula (9) to the aqueous phase, the mixture was mixed at 60 ° C. with an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.) at 10,000 rpm.
For 3 minutes. The resulting particle size is 0.52 μm
Met.

(Preparation of heat-sensitive recording material) On one side of a substrate coated with a double-sided undercoat in the same manner as in Example 1, a BC solution and B
In the order of the PC liquid, the application amount was 46.0 ml / m ² , 1
The coating was performed at 8.5 ml / m ² and dried. Then B
2.4 g of the capsule liquid (E) (solid content concentration 43%), 5.7 g of the capsule liquid (F) (solid content concentration 43%) on the surface opposite to the side where the C layer and the BPC layer were provided, Example 2
Of an electron-accepting compound emulsion (solid concentration 21
Wt.) 40 g, 20 wt.% Colloidal silica (Nissan Chemical Snowtex O) 1, 25 g, and structural formula (27)
Was mixed with 0.4 g of a 50% by weight aqueous solution of the compound represented by the formula (1), and dried by applying so that the dry weight became 13.1 g / m ² . Subsequently, the coating solution for the protective layer shown in Example 1 was dried on this coated material so as to have a dry weight of 2.5 g / m ² to obtain a heat-sensitive recording material of Example 2 according to the present invention.

Example 3 The procedure of Example 2 was repeated, except that the compound (G) represented by the following structural formula (G) was used as the surfactant polymer instead of the compound (A) of the present invention used in Example 2. In the same manner as in Example 2, a thermosensitive recording material was obtained.

[0133]

Embedded image

Comparative Example 2 Preparation of Capsule Solution (G) 5.6 g of the compound represented by the structural formula (1) and the structural formula (3)
1.5 g of the compound represented by Structural Formula (28), and 0.1 g of the compound represented by Structural Formula (29)
g, the compound represented by the structural formula (6) 0.7 g, the compound represented by the structural formula (4) 0.1 g, and the structural formula (6)
Is dissolved in 10.0 g of ethyl acetate by heating and cooled to 40 ° C., and then 6.4 g of Takenate D127N (manufactured by Takeda Pharmaceutical Co., Ltd.) and D110NN of Takenate D110NN (Takeda Pharmaceutical Co., Ltd.) 1.1)
g, and 0.2 g of n-butanol.
Stirred for 0 minutes.

The obtained solution was added to 30.0 g of a 6.0% solution of polyvinyl alcohol (PVA-217C: manufactured by Kuraray Co., Ltd.), and the number of rotation was 10 using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). 2,000r
The emulsion was dispersed at pm.

The obtained emulsion was further added with distilled water (40.0%).
g, 0.4 g of tetraethylenepentamine,
The encapsulation reaction was performed at 60 ° C. for 4 hours to prepare a capsule liquid (G) having an average particle diameter of 0.6 μm and a solid concentration of 27%. When the amount of water to be added to the emulsion was 15 g, which was the same as in Example 2, in order to increase the concentration, aggregation occurred during the capsule reaction and a desired capsule liquid could not be obtained.

(Preparation of Capsule Liquid (H)) Structural Formula (1)
5.5 g of the compound represented by the formula, 2.7 g of the compound represented by the structural formula (3), and the compound 1.1 represented by the structural formula (28)
g, 0.7 g of a compound represented by Structural Formula (29), 0.6 g of a compound represented by Structural Formula (30), 0.6 g of a compound represented by Structural Formula (4), and a compound represented by Structural Formula (6) 0.3 g of the compound was heated and dissolved in 11.1 g of ethyl acetate at 70 ° C. and cooled to 45 ° C., and then Takenate D-14 was added.
0 (manufactured by Takeda Pharmaceutical Co., Ltd.) and 1.1 g of Takenate d-750 (manufactured by Takeda Pharmaceutical Co., Ltd.) were added and stirred. The obtained solution was polyvinyl alcohol 6.0%.
Solution (PVA-217C: manufactured by Kuraray Co., Ltd.) 31.0
After adding g, the mixture was emulsified and dispersed at 10,000 rpm using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).

To the obtained emulsion, 43 g of distilled water and 0.4 g of tetraethylenepentamine were further added.
The encapsulation reaction was performed at 0 ° C. for 3 hours to prepare a capsule liquid (H) having an average particle diameter of 0.6 μm and a solid content concentration of 27%. When the amount of water to be added to the emulsion was 15 g, which was the same as in Example 2, in order to increase the concentration, aggregation occurred during the capsule reaction and a desired capsule liquid could not be obtained.

(Preparation of Thermosensitive Recording Material)
BC liquid and B
The application amount was 46.0 ml / m in the order of PC liquid.^Two, 1
8.5 ml / m^TwoAnd dried. Then B
On the side opposite to the side where the C layer and the BPC layer are provided,
4.2 g of the cell liquid (C) (solid concentration 27%),
Cell liquid (D) (solid content concentration 27%) 10.0 g, Example
Emulsion dispersion liquid (solid concentration 2
40 g, 20 wt% colloidal silica (Nissan)
Chemical Snowtex O) 1.25 g, and structural formula (2
Mix 0.4 g of a 50% by weight aqueous solution of the compound represented by 7).
Combined, the dry weight is 13.5 g / m^TwoApply to dry
Dried. Subsequently, the protective material shown in Example 1 was applied on this coated material.
The dry weight of the protective layer coating solution is 2.5 g / m ^TwoDried to be
Thus, a heat-sensitive recording material according to the present invention was obtained.

Comparative Example 3 (Preparation of Capsule Solution (I)) 5.6 g of the compound represented by the structural formula (1) and 1.5 g of the compound 1.5 represented by the structural formula (3)
g, the compound represented by the following structural formula (28) 1.1 g, the compound represented by the structural formula (29) 0.7 g, and the structural formula (3
0.7 g of the compound represented by formula (0), 0.1 g of the compound represented by formula (4), and 0.2 g of the compound represented by formula (6) were dissolved by heating in 10.0 g of ethyl acetate.
After cooling to 40 ° C., 6.4 g of Takenate D127N (manufactured by Takeda Pharmaceutical Co., Ltd.), Takenate D110N
1.1 g (manufactured by Takeda Pharmaceutical Co., Ltd.) and 0.2 g of n-butanol were added and stirred at 40 ° C. for 40 minutes.
The obtained solution was added to 30.0 g of a 10% sodium dodecylbenzenesulfonate solution, and then the rotation speed was set to 10.0 and 0,0 using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.).
Emulsification and dispersion were performed at 00 rpm.

[0141] The obtained emulsion was further added with distilled water (40.0%).
g, 0.4 g of tetraethylenepentamine,
The encapsulation reaction was performed at 60 ° C. for 4 hours to obtain a capsule solution (I) having a solid content of 43%.

(Preparation of Capsule Liquid (J)) Structural Formula (1)
5.5 g of the compound represented by the formula, 2.7 g of the compound represented by the structural formula (3), and the compound 1.1 represented by the structural formula (28)
g, 0.7 g of a compound represented by Structural Formula (29), 0.6 g of a compound represented by Structural Formula (30), 0.6 g of a compound represented by Structural Formula (4), and a compound represented by Structural Formula (6) 0.3 g of the compound was heated and dissolved in 11.1 g of ethyl acetate at 70 ° C. and cooled to 45 ° C., and then Takenate D-14 was added.
6.2 (Takeda Pharmaceutical Co., Ltd.) and 1.1 g of Takenate D-750 (Takeda Pharmaceutical Co., Ltd.) were added and stirred. The obtained solution was added to 30.0 g of a 10% sodium dodecylbenzenesulfonate solution, and an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.) was used.
Emulsification dispersion was performed at 000 rpm.

To the obtained emulsion were added 43 g of distilled water and 0.4 g of tetraethylenepentamine.
The encapsulation reaction was carried out at 0 ° C. for 3 hours, and the solid content concentration was 4
A 3% capsule liquid (J) was obtained.

(Preparation of Thermosensitive Recording Material) As in Example 1, a BC solution and a B solution
In the order of the PC liquid, the application amount was 46.0 ml / m ² , 1
The coating was performed at 8.5 ml / m ² and dried. Then B
On the side opposite to the side where the C layer and the BPC layer were provided, 2.4 g of the capsule liquid (1) (solid content concentration 43%), 5.7 g of the capsule liquid (J) (solid content concentration 43%) , An electron-accepting compound emulsion dispersion according to Example 2 (solids concentration 2
1% by weight) 40 g, 20% by weight colloidal silica (Nissan Chemical Snowtex O) 1.25 g, and structural formula (2
0.4 g of a 50% by weight aqueous solution of the compound represented by 7) was mixed, and the mixture was dried so as to have a dry weight of 13.5 g / m ² . Subsequently, the coating liquid for the protective layer shown in Example 1 was dried on this coated material so that the dry weight became 2.5 g / m ² , to obtain a heat-sensitive recording material according to the present invention.

(Example 4) 5.0 g of a diazonium compound represented by the following structural formula (35), 15 g of methylene chloride, 5 g of tricresyl phosphate, 15 g of trimethylolpropane trimethacrylate, and the present invention represented by the following structural formula 1. Surfactant polymer compound (A) according to
0 g and Takenate D-110 (manufactured by Takeda Pharmaceutical Co., Ltd.) 20 g were added and uniformly mixed to prepare an oil phase solution.

[0146]

Embedded image

[0147]

Embedded image

After the obtained oil phase solution was mixed with 60 g of water, the mixture was emulsified at 8000 rpm using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.), and an encapsulation reaction was carried out at 40 ° C. for 3 hours to give an average particle size of 1%. A capsule liquid having a concentration of 0.5 μm and a solid concentration of 40% was prepared. An ion exchange resin (Organo Corporation: MB-3) is added to the liquid obtained after the reaction.
After adding 10 ml and stirring for 30 minutes, the solution was filtered to obtain a capsule solution.

Next, 4.3 g of a coupler compound represented by the following structural formula (36), 0.7 g of a coupler compound represented by the following structural formula (37), 5 g of 1,2,3-triphenylguanidine, and tricresyl 0.8 g of phosphate and 0.29 g of diethyl maleate were added to 25 g of ethyl acetate.
g and dissolved. The obtained solution was mixed with an aqueous phase obtained by mixing 40 g of an 8% by weight aqueous solution of polyvinyl alcohol, 15 g of water, and 0.5 g of sodium dodecylbenzenesulfonate, and then mixed with an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). Emulsification was performed so that the average particle size became 0.5 μm at 000 rpm.

[0150]

Embedded image

(Preparation of thermosensitive recording material) Capsule solution containing the diazonium compound (solid content: 40% by weight)
2.8 g, 15.0 g of a coupler (solid content temperature 16% by weight) emulsion and 0.73 g of 20% by weight colloidal silica (Snowtex O: manufactured by Nissan Chemical Co., Ltd.) were stirred and mixed, and the mixed liquid was used in Example. 13. solids on the support used in 1.
The coating was dried at 5 g / m ² and dried to form a heat-sensitive recording layer. Next, the protective layer coating solution of Example 1 was applied on the formed heat-sensitive recording layer so that the solid content after drying was 2.5 g / m ² , and dried to produce a transparent heat-sensitive recording material.

Comparative Example 4 Methylene chloride 1 was added to 5.0 g of a diazonium compound represented by the following structural formula (35).
5 g, tricresyl phosphate 5 g, trimethylolpropane trimethacrylate 15 g and m-xylylene diisocyanate trimethylolpropane 3: 1
20 g of a 75% by weight solution of the adduct in ethyl acetate (Takeda Pharmaceutical Co., Ltd .: Takenate D110N) was added and uniformly mixed to prepare an oil phase solution.

[0153]

Embedded image

The obtained oil phase solution was mixed with an aqueous phase of 60 g of a 7% by weight aqueous solution of polyvinyl alcohol (PVA217E: manufactured by Kuraray Co., Ltd.), and emulsified at 8000 rpm using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.). Done. After further adding 50 g of water to the obtained emulsion, an encapsulation reaction was carried out at 40 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 1.5 μm and a solid concentration of 25%. After the completion of the reaction, the solution obtained was replaced with an ion exchange resin (MB-
3: Organo Co., Ltd.), and stirred for 30 minutes, followed by filtration to obtain a capsule liquid. When water was not added to the emulsion to further increase the concentration, aggregation occurred during the capsule reaction, and the desired capsule liquid could not be obtained.

(Preparation of thermosensitive recording material) Capsule solution containing the above diazonium compound (solid concentration 25% by weight)
5.0 g, 15.0 g of the coupler (solid content 16% by weight) emulsion obtained in Example 4, and 0.73 g of 20% by weight colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.)
Was stirred and mixed, and the mixed solution was applied onto the support used in Example 1 so as to have a solid content of 15 g / m ² and dried to form a heat-sensitive recording layer. Next, the protective layer coating solution of Example 1 was dried on the heat-sensitive recording layer in a solid content of 2.5 g /
m ² to obtain a transparent heat-sensitive recording material.

Example 5 A capsule liquid (A), a capsule liquid (B), and an emulsified dispersion of an electron-accepting compound were prepared in the same manner as in Example 1. Next, as in the first embodiment, BC
2.4 g of the capsule liquid (A) (solid content concentration 43%), 5.7 g of the capsule liquid (B) (solid content concentration 43%) on the opposite side of the support provided with the layer and the BPC layer, and electron acceptability. Compound emulsified dispersion (solid content: 21%) 40 g, 48% styrene-butadiene latex 3.0 g, 20 wt% colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.)
25 g and 0.4 g of a 50% by weight aqueous solution of the compound represented by the structural formula (27) were stirred and mixed, and the mixed solution was applied to a solid content of 13.8 g / m ² , dried, and then subjected to thermal recording. A layer was formed. Next, the protective layer coating solution of Example 1 was applied onto the formed heat-sensitive recording layer so that the solid content after drying was 2.5 g / m ² , and dried to prepare a heat-sensitive recording material.

Example 6 A capsule liquid (E), a capsule liquid (F), and an emulsified dispersion of an electron-accepting compound were prepared in the same manner as in Example 2. Next, as in the first embodiment, BC
2.4 g of the capsule liquid (E) (solid content concentration 43%), 5.7 g of the capsule liquid (F) (solid content concentration 43%) on the opposite side of the support provided with the layer and the BPC layer, and electron acceptability. Compound emulsified dispersion (solid content: 21%) 40 g, 48% styrene-butadiene latex 3.0 g, 20 wt% colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.)
25 g and 0.4 g of a 50% by weight aqueous solution of the compound represented by the structural formula (27) were stirred and mixed, and the mixed solution was applied to a solid content of 13.8 g / m ² , dried, and then subjected to thermal recording. A layer was formed. Next, the protective layer coating solution of Example 1 was applied onto the formed heat-sensitive recording layer so that the solid content after drying was 2.5 g / m ² , and dried to prepare a heat-sensitive recording material.

Comparative Example 5 In the same manner as in Comparative Example 1, a capsule liquid (C), a capsule liquid (D), and an emulsified dispersion of an electron-accepting compound were prepared. Next, as in the first embodiment, BC
2.4 g of the capsule liquid (C) (solid content concentration 27%), 5.7 g of the capsule liquid (D) (solid content concentration 27%) on the opposite side of the support provided with the layer and the BPC layer, and electron acceptability. Compound emulsified dispersion (solid content: 21%) 40 g, 48% styrene-butadiene latex 3.0 g, 20 wt% colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.)
25 g and 0.4 g of a 50% by weight aqueous solution of the compound represented by the structural formula (27) were stirred and mixed, and the mixed solution was applied to a solid content of 14.2 g / m ² , dried, and then subjected to thermal recording. A layer was formed. Next, the protective layer coating solution of Example 1 was applied onto the formed heat-sensitive recording layer so that the solid content after drying was 2.5 g / m ² , and dried to prepare a heat-sensitive recording material.

Comparative Example 6 A capsule liquid (G), a capsule liquid (H), and an emulsified dispersion of an electron-accepting compound were prepared in the same manner as in Comparative Example 2. Next, as in the first embodiment, BC
2.4 g of the capsule liquid (G) (solid content concentration 27%), 5.7 g of the capsule liquid (H) (solid content concentration 27%) on the opposite side of the support provided with the layer and the BPC layer, and electron acceptability. Compound emulsified dispersion (solid content: 21%) 40 g, 48% styrene-butadiene latex 3.0 g, 20 wt% colloidal silica (Snowtex O: manufactured by Nissan Chemical Industries, Ltd.)
25 g and 0.4 g of a 50% by weight aqueous solution of the compound represented by the structural formula (27) were stirred and mixed, and the mixed solution was applied to a solid content of 14.2 g / m ² , dried, and then subjected to thermal recording. A layer was formed. Next, the protective layer coating solution of Example 1 was applied onto the formed heat-sensitive recording layer so that the solid content after drying was 2.5 g / m ² , and dried to prepare a heat-sensitive recording material.

<Printing method and performance evaluation>
6 and the thermal recording materials obtained from Comparative Examples 1 to 6 were evaluated as follows.

(Evaluation of Coloring Density) Each of the above-mentioned heat-sensitive recording materials was applied to a thermal head by applying a thermal energy of 60 mj / m.
thermal printer (TRT-16 type adjusted to m ^2:
The image was printed using a Nagano Japan Radio Co., Ltd.), and the density of the obtained image was measured using a Macbeth densitometer (RD-918: Macbeth). The results are shown in Table 1.

(Evaluation of background preservability and image preservability) The above-mentioned heat-sensitive recording material and the recording material after printing were subjected to 60 ° C., 30%
The transmission density of the background and the image area after storage for 2 weeks under RH was measured by a Macbeth densitometer (RD-918: manufactured by Macbeth), and the difference between the density and the density before storage is shown in Table 1 below. The values in Table 1 indicate that the temperature (fog) increased with storage.

(Evaluation of Water Resistance) 0.1 ml of a water drop was dropped on the printed portion and the unprinted portion of the heat-sensitive recording materials of Examples 1 to 6 of the present invention, and rubbed five times with a finger after 10 seconds. Although the peeling of the heat-sensitive recording layer was visually observed by wiping, the peeling that would be a problem in practical use was not observed, and the heat-sensitive recording layer having excellent resistance to wetting and rubbing and having excellent water resistance was formed. all right.

[0164]

[Table 1]

As is clear from Table 1, the heat-sensitive recording material according to the present invention not only has high color density at low applied energy and high sensitivity, but also has low fog at the time of raw storage and after printing, and has high water resistance. Considering the gender evaluation results,
It can be seen that by adding the hydrophobic polymer compound, a heat-sensitive recording material having a good balance of water resistance / color-forming properties can be obtained, and has desirable characteristics as a heat-sensitive recording material. In addition, a high-concentration capsule solution can be easily obtained, which is preferable in terms of production suitability.
On the other hand, as is apparent from Comparative Examples 1 to 3, the microcapsule solution containing no surfactant polymer according to the present invention causes agglomeration due to a high concentration, and has a problem in production suitability. It was found that it was difficult to obtain high color density.

[0166]

As described above, the heat-sensitive recording material of the present invention comprises:
The color density of the image is high, the water resistance, oil resistance,
The effect that the adhesive strength was excellent was shown. Further, according to the method for producing a heat-sensitive recording material of the present invention, a heat-sensitive recording material having the above-described excellent properties can be efficiently produced without necessarily adding a water-soluble polymer, with high productivity. did it.

Claims (5)

[Claims] 1. A heat-sensitive recording material having a heat-sensitive recording layer provided on a support, wherein at least one of the heat-sensitive recording layers has a substantially colorless color-forming component A and a color-forming component that reacts with the color-forming component A to form a color. A colorless color component B, and the color component A
And that at least one of the color-forming components B is encapsulated in microcapsules produced in the presence of at least one surfactant polymer containing at least 5 mol% of a unit represented by the following general formula (I). Characteristic thermal recording material. Embedded image In the general formula (I), R represents an aliphatic hydrocarbon group having 4 to 22 carbon atoms. A represents a divalent aliphatic group having 1 to 50 carbon atoms. M represents a cation or a cationic root capable of forming a salt with sulfonic acid. B represents -O- or -NH-. m1
And m2 represent 0 or 1, respectively. 2. The method according to claim 1, wherein the thermosensitive recording layers of cyan, magenta and yellow are sequentially provided on a support.
2. The heat-sensitive recording material according to item 1. 3. The method according to claim 1, wherein the color-forming component A and the color-forming component B are a combination of an electron-donating dye precursor and a developer, or a combination of a diazonium salt compound and a coupler. The multicolor heat-sensitive recording material as described above. 4. A method for producing a thermosensitive recording material having a thermosensitive recording layer provided on a support, comprising: a substantially colorless color-forming component A; and a substantially colorless color-forming component A that reacts with the color-forming component A to form a color. A step of producing microcapsules containing at least one of the color-forming components B in the presence of at least one surfactant polymer containing at least 5 mol% of the unit represented by the general formula (I); Preparing a thermosensitive recording layer coating solution containing a microcapsule containing either the component A or the coloring component B, and the other coloring component; and coating the thermosensitive recording material layer coating solution on a support. Forming a heat-sensitive recording layer by heating. 5. The method according to claim 4, wherein the color-forming component A and the color-forming component B are a combination of an electron-donating dye precursor and a developer, or a combination of a diazonium salt compound and a coupler. Manufacturing method of thermal recording material.