JPH0319075B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a diazo-fixed heat-sensitive recording material that develops color with high density during heat-sensitive recording and has excellent storage stability. In recent years, high-speed printers, facsimile machines, etc. have made remarkable progress in response to society's demand for outputting large amounts of information as hard copies as quickly as possible. Electrophotography, electrostatic recording, discharge recording, inkjet recording, thermosensitive recording, and the like are known as methods for forming images on recording media according to electrical information, such as high-speed printers and facsimiles. Among these methods, the thermal recording method has been rapidly becoming popular in recent years because the apparatus is relatively simple and the recording paper is also relatively inexpensive. As one method of the heat-sensitive recording method, a heat-sensitive recording sheet made by combining a color-forming substance such as crystal violet lactone and a phenolic compound such as bisphenol A is described in, for example, Japanese Patent Publication No. 14039/1983. has been described and is already known. These thermosensitive recording sheets are currently widely used as office copy paper, recording paper for various recorders, electrocardiographs, calculators, computer terminals, facsimiles, and the like. However, with the above conventional method, if the background is heated incorrectly after printing, the background may become colored and the print may become unreadable, or there is a possibility that it may be tampered with after printing.
Improvements are strongly desired. The present inventors conducted research with the intention of providing a fixable heat-sensitive recording medium that solved this problem, and first developed a guanidine derivative having a specific general formula as a basic substance that promotes the reaction between a diazonium salt and a coupler compound. We have already proposed that by using the method, it is possible to provide a fixable heat-sensitive recording medium with high sensitivity and excellent storage stability (Japanese Patent Application Laid-Open No. 57-45094,
Publication No. 57-125091). As a result of further development by the present inventors, () a fine particle dispersion of an organic basic compound containing a diazonium salt and a coupler compound and acting as a color developer that melts with heat and exhibits a basic atmosphere is contained in the same layer. A diazo-fixed heat-sensitive recording material comprising a light-sensitive and heat-sensitive layer provided on a support, or () a light-sensitive and heat-sensitive layer provided on a support, the light-sensitive and heat-sensitive layer containing a diazonium salt and an acid compound for preventing precoupling. It consists of a photosensitive layer and a heat sensitive layer containing as a color developer a fine particulate dispersion of an organic basic compound that is melted by heat and exhibits a basic atmosphere, and in at least one of the photosensitive layer and the heat sensitive layer. In a diazo-fixed heat-sensitive recording material containing a coupler compound, at least one compound selected from the group of compounds represented by the following general formulas () and () is used as the coupler compound, particularly in fine particles with a particle size of 0.5 to 10 microns. By using it as a dispersion, the above objects were achieved to a higher degree, and a fixable heat-sensitive recording material with high sensitivity and excellent storage stability was obtained. (In the general formulas () and (), R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom, an alkyl group having 18 or less carbon atoms, or an alkoxy group. R ₄ represents an alkyl group having 2 or less carbon atoms. (n represents an integer of 1 or 2.) The effect of improving storage stability by using the coupler compounds represented by the general formulas () and () is evident not only with hydrophobic guanidine derivatives but also with widely known organic basic compounds. Particularly preferred organic basic compounds include the following guanidine derivatives, although they are also recognized when used as coloring agents. [In the formula, R ₅ , R ₆ , R ₇ , R ₈ and R ₉ are hydrogen and the number of carbon atoms
represents an alkyl, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue of 18 or less,
R ₁₀ is lower alkylene, phenylene, naphthylene or

[Formula] (wherein X represents lower alkylene, SO ₂ , S ₂ , S, O, -NH- or a single bond), and the aryl group in the formula is lower alkyl, alkoxy, nitro, acylamino, alkylamino Also included are those having substituents selected from groups and halogens. ] As the diazonium salt used in the present invention, any compound used in conventionally known diazo type copying materials can be used. For example, compounds represented by the following general formulas (), (), () can be used. It can be used particularly preferably. In the formula, R ₁₁ and R ₁₂ are alkyl having 1 to 5 carbon atoms,
or alkoxyl, oxyalkyl, benzyl, substituted benzyl, benzoyl, substituted benzoyl, phenyl group, hydrogen atom, etc., and Y and Z
represents a halogen atom, alkyl having 1 to 5 carbon atoms, carboxyl, alkoxyl having 1 to 5 carbon atoms, nitro, acetoxy group, etc., and m and n represent 0 or a positive integer of 4 or less. Also, X is Cl ^- , Br ^- ,
It represents anions such as SO ^- ₄ , NO ^- ₃ , PF ^- ₆ , ClO ^- ₄ , BF ^- ₄ and ions to which ZnCl ₂ , CdCl ₂ or SnCl ₄ are added. Specific examples include 4-N,N-dimethylaminobenzenediazonium chloride, 3-chloro-4-
N,N-dimethylaminobenzenediazonium chloride, 4-N,N-diethylaminobenzenediazonium chloride, 2,5-diethoxy-4-
N,N-diethylaminobenzenediazonium chloride, 4-N-ethyl-N-hydroxyethylaminobenzenediazonium chloride, 4-N,
Examples include N-diethoxyaminobenzenediazonium chloride, 4-phenylaminobenzenediazonium chloride, and 4-N-(P-methoxyphenyl)-aminobenzenediazonium chloride. In the formula, R ₁₃ is −CH ₂ CH ₂ OCH ₂ CH ₂ − or −
CH ₂ OCH ₂ CH ₂ −, −CH ₂ CH ₂ CH ₂ CH ₂ −, etc. X, Y, Z, m and o have the same meanings as in the general formula (). Specific compound examples include 4-morpholinobenzenediazonium chloride, 2,5-diethoxy-4-morpholinobenzenediazonium chloride, 4-oxazolidinobenzenediazonium chloride, and 3-methyl-4-piperidinobenzene. Examples include diazonium chloride. In the formula, R ₁₄ represents an alkyl group or an aryl group.
Moreover, X, Y, Z, m and n have the same meanings as in the general formula (). Specific compound examples include 4-ethylmercapto-2,5-diethoxybenzenediazonium chloride, 4-tolylmercapto-2,5-diethoxybenzenediazonium chloride, and 4-benzylmercapto-2,5-dimethoxybenzenediazonium chloride. and so on. These diazonium salts can be dissolved in water or an organic solvent, or dispersed in the form of fine particles in an appropriate solvent, and then coated on a support. In addition, an acid compound can be used in the photosensitive and heat-sensitive layer to stabilize the diazonium salt and prevent precoupling, but this is possible by using any organic or inorganic acid compound used in conventionally known diazo type copying materials. Specific examples include tartaric acid,
Citric acid, boric acid, lactic acid, gluconic acid, phosphoric acid,
Trichloroacetic acid, dichloroacetic acid, cyanoacetic acid, oxalic acid, malonic acid, maleic acid, etc. are all preferably used. These acid compounds are preferably used in a weight ratio of 1.0% to 30%, more preferably 5 to 15%, based on the organic basic compound. The coupler compound represented by the general formula () or () is a blue azo dye-forming coupler;

【formula】

[Formula] may be substituted at any position on the benzene ring of the general formula () or (). Specific examples of general formula () are shown in Table 1, but this does not limit the present invention. Further, specific examples of general formula () are shown in Table-2. Dissolve these coupler compounds in water or an organic solvent, or use a dispersion means such as a ball mill, sand grinder, or attritor to obtain particles with a particle size of 10μ.
It can be contained in the light and heat sensitive layer as the following fine particulate dispersion. In addition, the coupler compound is a combination of compounds selected from the above general formula () or (), or a yellow coupler having an active methylene group, a polyvalent phenolic coupler, a coupler having a pyrazolone ring, etc. according to the general formula () or (). In combination with selected compounds, dye combinations may be produced that exhibit desired spectral absorption properties. Furthermore, during dispersion, the coupler compound may be dispersed alone, but it may also be co-dispersed with an organic basic compound or other additives if necessary. If the organic basic compound used as a color developer is soluble in the water or organic solvent used as a solvent for the coating solution when applied to the support, the pH of the coating solution will increase, causing fogging on the background and deterioration of storage stability. Therefore, it is desirable to exist as a discontinuous fine particle dispersion in the coating layer, and the solubility in water at 20°C is 1.0.
g/ or less, the humidity and heat storage stability is good, and heterocyclic compounds such as aliphatic amines, pyrrolidine derivatives, imidazole derivatives, imidazoline derivatives, piperidine derivatives, etc. can also be suitably used, but in particular, the following general formula () When the hydrophobic guanidine derivatives () and () are used as a color developer, it is possible to obtain a fixed heat-sensitive recording material which has excellent storage stability under high temperature and high humidity conditions and which develops color with high sensitivity.
Further, as the color developer, one having a melting point in the range of 100 to 170°C can be particularly preferably used. The color developer may be dispersed alone using a dispersion means such as a ball mill, a sand grinder, an attritor, etc., but it may also be co-dispersed with a coupler compound and other additives as necessary. or [In the formula, R ₅ , R ₆ , R ₇ , R ₈ and R ₉ are hydrogen and the number of carbon atoms
represents an alkyl, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue of 18 or less,
R ₁₀ is lower alkylene, phenylene, naphthylene or

[Formula] (wherein X represents lower alkylene, SO ₂ , S ₂ , S, O, -NH- or a single bond), and the aryl group in the formula is lower alkyl, alkoxy, nitro, acylamino, alkylamino It also includes those having substituents selected from groups and halogens.] Typical examples thereof are shown in Table 3, but are not limited thereto. In the table

[Formula] represents a cyclohexyl group.

【formula】

【formula】

【formula】

【formula】

These derivatives of quanidine shown above can be easily synthesized by known methods or methods similar thereto. In addition, examples of binder materials for forming the photosensitive and thermosensitive layer of the present invention include cornstarch, gum arabic, glue, gelatin, casein, methylcellulose, ethylcellulose, and aqueous solvents.
Starch or its modified products and derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylamide, carboxymethyl starch, dialdehyde starch, polyvinyl alcohol or its modified products and derivatives, polyvinylpyrrolidone, isobutylene-maleic anhydride copolymer, polyacrylic acid Salt, styrene-maleic anhydride copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-butadiene rubber (=SBR), methacrylate-butadiene rubber (=
MBR), nitrile butadiene rubber (=NBR), polymethyl methacrylate, polypropylene, polyacrylonitrile, synthetic resin emulsion such as acrylic ester, etc., and these binder materials can be used alone or in combination. Furthermore, in the case of an organic solvent system, the above-mentioned synthetic resin can be used by dissolving it in an organic solvent without emulsifying it. Since the coupling reaction of diazonium salts is promoted in polar solvents such as water, the storage stability of fixed heat-sensitive recording materials using diazonium salts, especially under high temperature and high humidity conditions, is limited by the use of binder materials with a low equilibrium moisture content. It can also be greatly improved by selecting
In addition, when using an aqueous solvent, water-resistant agents such as formalin, glyoxal, chromium alum, glutaraldehyde, melamine/formalin resin, urea/formalin resin, etc., which are usually used in water-soluble polymer binders, may be used. However, it is possible to improve the storage stability. Specific examples of pigments used in the photosensitive and heat-sensitive layer of the present invention include kaolin, calcined kaolin, talc, waxite, diatomaceous earth, styrene resin particles, calcium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, Examples include titanium oxide, barium carbonate, urea-formalin filler, cellulose filler, aluminum oxide, etc., but from the viewpoint of thermal head matching properties such as scum and statesking, JP-A No. 53-118059, 54-258453,
The oil absorption as described in 54-118846, 54-118847 is
According to the measurement method specified in JISK5101, 80ml to 500ml/
It is desirable to use 100 g of an oil-absorbing pigment, and especially in layers that are in direct contact with the heat head, it is desirable to use an oil-absorbing pigment that exhibits the above-mentioned oil absorption in calcined kaolin, urea-formalin fillers, etc. Other auxiliary ingredients include zinc chloride, zinc sulfate, sodium citrate, etc. to suppress or assist color development.
Saccharides such as guanidine thiourea sulfate, calcium gluconate, sorbitol, and sugar rose are used, and if necessary, UV inhibitors are added, and waxes and metal soaps are added to improve staining and color sensitivity. It can be used. Specific examples of waxes include paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty acid amides such as stearic acid amide, laurylamide, myristylamide, hardened tallow acid amide, and palmitin. Examples include acid amide, oleic acid amide, acetamide, coconut fatty acid amide, methylolated products of these fatty acid amides, methylene bis stearamide, ethylene bis stearamide, and higher fatty acid esters. Metal soaps include higher fatty acid polyvalent metal salts, namely zinc stearate, aluminum stearate,
Examples include calcium stearate and zinc oleate. Although these can be used alone as dispersed, they can also be used as co-dispersed with organic basic compounds, coupler compounds, etc. In addition to paper, synthetic resin film,
Laminated paper can also be used, and when paper is used as a support, if the photosensitive and heat-sensitive layer is applied directly onto the support, the diazonium salt will penetrate into the pores of the paper base and be impregnated into the inside, so a large amount of diazonium will be absorbed. Since salt is required, the sensitivity of light fixing due to exposure after thermal printing may decrease, and the image may lack clarity. To prevent this drawback, if necessary, silica sol may be applied to the paper base in advance. , alumina, titanium oxide, kaolin, etc., or a combination of these with a polymeric material such as starch, casein, polyvinyl alcohol, polyvinyl acetate emulsion, etc., and then the photosensitive/thermosensitive layer may be applied. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 A coating solution for a photosensitive and thermosensitive layer is prepared according to the following formulation, and coated onto a support so that the coating weight after drying is 9.5 g/m ² and dried to prepare a fixable thermosensitive recording material. The unit is parts by weight. Water 200 Oxalic acid 2.5 2,5-diethoxy-4-morpholinobenzenediazonium tetrafluoroborate 2 Calcined kaolin 10 Part A 5 Part B 100 10% polyvinyl alcohol 200 Parts A and B were prepared in a ball mill using the following composition. The mixture was prepared by pulverization and dispersion for 48 hours. A liquid 10g (Compound (1) in Table 1) (Melting point 236-9℃) 10% methylcellulose 5g Water 15g Solution B

[Formula] 55g (Compound (7) in Table 3) Ethylene bisamide 45g 10% methyl cellulose 50g Water 150g Example 2 Instead of using compound (1) in Table 1 as liquid A in Example 1 A fixable heat-sensitive recording material was prepared in the same manner as in Example 1 except that (compound (3) in Table 1) (melting point 210-211°C) was used. Example 3 Instead of using compound (7) in Table 3 as liquid B in Example 1,

A fixable heat-sensitive recording material was prepared in the same manner as in Example 1 except that the compound (11) in Table 3 was used. Comparative Example 1 In Example 1, 2-hydroxy-3-naphthoic acid was used instead of using Compound (1) in Table 1 as Solution A.
A fixable heat-sensitive recording material was prepared in the same manner as in Example 1 except that 2'-ethoxyanilide was used. The thus obtained fixable heat-sensitive recording material was thermally printed using a facsimile machine (Toshiba KB-4800), and then the diazonium salt was decomposed and fixed by exposing the entire surface to ultraviolet light. The print density obtained as described above was measured using a Macbeth densitometer (RD-514). Table the value -
4. Table 4 also shows the results of the storage stability test. The storage stability test represents the results of a humidity and heat resistance test when a sample formed by preparing a coating solution, applying it and drying it was left in a dark place at 40℃ and 90% relative humidity for 24 hours. It is fixed and the skin density measured with a Macbeth densitometer is shown.
4.

[Table] Example 4 A photosensitive layer containing a diazonium salt was prepared with the following formulation, and the coating amount after drying on the support was 2.0 g/m ²
Apply it so that it looks like this. Oxalic acid 2g Thiourea 2g 2,5-diethoxy-4-morpholinobenzenediazonium tetrafluoroborate 2g Calcined kaolin 4g 10% polyvinyl alcohol 30g Water 100ml A heat-sensitive layer containing a color developer prepared with the following formulation on the above photosensitive layer The coating amount after drying is 8.0
g/m ² to prepare a diazo-fixed heat-sensitive recording material. Water 100g Calcined kaolin 20g Solution A 5g Solution B 100g 10% polyvinyl alcohol 120g 50% melamine formalin waterproofing agent 2g Solutions A and B were prepared by grinding and dispersing the following formulations in a ball mill for 48 hours. A liquid 10g (Compound (1) in Table 1) 10% methylcellulose
5g water 15g Liquid B

[Formula] 55g (Compound (7) in Table 3) Ethylene bisamide
45g 10% methyl cellulose 50g Water 150g Example 5 Instead of using compound (1) in Table 1 as liquid A in Example 4 A diazo-fixed thermosensitive recording material was prepared in the same manner as in Example 4 except that (compound (4) in Table 1) (melting point 176-177°C) was used. Example 6 Instead of using compound (7) in Table 3 as liquid B in Example 4,

A diazo-fixed heat-sensitive recording material was prepared in the same manner as in Example 4 except that the compound (11) in Table 3 was used. Comparative Example 2 In Example 4, 2-hydroxy-3-naphthoic acid was used instead of using Compound (1) in Table 1 as Solution A.
A diazo-fixed heat-sensitive recording material was prepared in the same manner as in Example 4 except that 2'-ethoxyanilide was used. The thus obtained diazo-fixed heat-sensitive recording material was thermally printed using a facsimile (Toshiba KB-4800), and then the entire surface was exposed to ultraviolet light to decompose and fix the diazonium salt. The print density obtained as described above was measured using a Macbeth densitometer (RD-514), and the values are shown in Table-5.
Shown below. Table 5 also shows the results of the storage stability test. The storage stability test is a humidity and heat resistance test in which the prepared sample after coating is left in a dark place at 40℃ and 90% relative humidity for 24 hours, and the sample is exposed to 60℃.
Table 5 shows the results of a heat resistance test in which the samples were left in a dryer for 24 hours. After each treatment, the entire surface was exposed to light and fixed, and the skin density measured with a Macbeth densitometer is shown in Table 5.

[Table] Example 7 Instead of using compound (1) in Table 1 in Example 6, compound (2) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 8 Instead of using compound (1) in Table 1 in Example 6, compound (5) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 9 Instead of using compound (1) in Table 1 in Example 6, compound (6) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 10 In Example 6, instead of using compound (1) in Table 1, compound (7) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 11 Instead of using compound (1) in Table 1 in Example 6, compound (8) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 12 Instead of using compound (1) in Table 1 in Example 6, compound (9) in Table 1 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 13 Instead of using compound (1) in Table 1 in Example 6, compound (1) in Table 2 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. Example 14 In Example 6, instead of using compound (1) in Table 1, compound (5) in Table 2 was used. A diazo-fixed heat-sensitive recording medium was prepared using the following method. These obtained samples were tested in the same manner as in Table 5, and the results are shown in Table 6.

【table】

【table】

Claims (1)

[Scope of Claims] 1. Supports a light-sensitive and heat-sensitive layer containing, in the same layer, a fine particle dispersion of an organic basic compound containing a diazonium salt and a coupler compound and serving as a color developer that melts with heat and exhibits a basic atmosphere. A diazo-fixed heat-sensitive recording material provided on a body, characterized in that the coupler compound is at least one compound selected from the group of compounds represented by the following general formulas () and (). An excellent diazo-fixed thermal recording material. (In the general formulas () and (), R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom, an alkyl group having 18 or less carbon atoms, or an alkoxy group. R ₄ represents an alkyl group having 2 or less carbon atoms. (n represents an integer of 1 or 2) 2. The diazo with excellent preservability according to claim 1, wherein the organic basic compound is a hydrophobic guanidine derivative represented by the following general formula () or (). Fixed heat-sensitive recording material. [In the formula, R ₅ , R ₆ , R ₇ , R ₈ and R ₉ are hydrogen and the number of carbon atoms
represents an alkyl, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue of 18 or less,
R ₁₀ represents lower alkylene, phenylene, naphthylene, or [Formula] (wherein X represents lower alkylene, SO ₂ , S ₂ , S, O, -NH-, or a single bond), and the aryl group in the formula represents lower Also included are those having substituents selected from alkyl, alkoxy, nitro, acylamino, alkylamino groups and halogen. ] 3 A photosensitive and thermosensitive layer is provided on a support, and the photosensitive and thermosensitive layer contains a diazonium salt, a photosensitive layer containing an acid compound for preventing precoupling, and an organic basic compound that melts with heat and exhibits a basic atmosphere. consisting of a heat-sensitive layer containing a particulate dispersion as a color developer, and
In a diazo-fixed heat-sensitive recording material in which at least one of the photosensitive layer and the heat-sensitive layer contains a coupler compound, the coupler compound is at least one compound selected from the group of compounds represented by the general formulas () and (). A diazo-fixed thermal recording material with excellent storage stability characterized by being made of one type of compound. (In the general formulas () and (), R ₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom, an alkyl group having 18 or less carbon atoms, or an alkoxy group. R ₄ represents an alkyl group having 2 or less carbon atoms. (n represents an integer of 1 or 2.) 4. The diazo with excellent preservability according to claim 3, wherein the organic basic compound is a hydrophobic guanidine derivative represented by the following general formula () or (). Fixed heat-sensitive recording material. [In the formula, R ₅ , R ₆ , R ₇ , R ₈ and R ₉ are hydrogen and the number of carbon atoms
represents an alkyl, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue of 18 or less,
R ₁₀ represents lower alkylene, phenylene, naphthylene, or [Formula] (wherein X represents lower alkylene, SO ₂ , S ₂ , S, O, -NH-, or a single bond), and the aryl group in the formula represents lower Also included are those having substituents selected from alkyl, alkoxy, nitro, acylamino, alkylamino groups and halogen. ]