JPS6112390A - Fixable-type thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a fixable-type thermal recording material capable of forming a color with high density by thermal recording and having excellent preservability, by using a specified compound as a color forming adjuvant in a photosensitive thermal recording layer comprising a diazonium salt, a coupler compound, a color forming adjuvant and a color developer. CONSTITUTION:A compound of general formula( I ), wherein R is alkyl or aralkyl, and n is an integer of 1-3, is used as a color forming adjuvant in a fixable- type thermal recording material wherein a photosensitive thermal recording layer comprising particulate dispersed materials of a diazonium salt, a coupler compound, a color forming adjuvant and a color developer consisting of an organic basic compound melted when being heated to provide a basic atmosphere, in the same layer or in two or more layers, is provided on a base. The compound used as the color forming adjuvant may be, for example, ethylene glycol bis (p-benzyloxycarbonylphenyl) ether, which is heat-fusible, is difficultly soluble or insoluble in water, and is used in a particulate form with a particle diameter of 0.1- 10mum. The amounts of the diazonium salt, the coupler compound and the adjuvant used are preferably in weight ratios of 1:(0.1-10):(0.1-20).

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a fixable heat-sensitive recording material that develops color with high p-density during heat-sensitive recording and has excellent storage stability.

However, prior art and its problems In recent years, high-speed printers, facsimiles, etc. have made remarkable progress in response to society's demand for outputting large amounts of information as hard copies as quickly as possible. 2. Description of the Related Art Electronic recording, electrostatic recording, discharge recording, inkjet recording, thermosensitive recording, and the like are known as methods for forming images on recording media according to alpha information, such as in 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 of a combination of a color-forming substance such as crystal violet lactate and a phenolic compound such as bisphenol A is described in, for example, Japanese Patent Publication No. 14039/1983. 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, in the above-mentioned conventional method, if the printing is mistakenly heated after printing, the background becomes colored and the printing becomes unreadable, and there is a possibility that the printing may be tampered with.Therefore, 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 discovered a guanidine derivative having a specific general formula as a basic substance that promotes the reaction between a diazonium salt and a coupler compound. By using scales, it was possible to provide fixable heat-sensitive recording body sound with high sensitivity and excellent storage stability.
-45094, Publication No. 57-125091).

However, in recent years, there has been an increasing demand for higher color development sensitivity in thermal recording methods. This is widely recognized in type thermosensitive recording materials, and there has been a demand for fixing type thermosensitive recording materials that develop color with high density and have excellent storage stability.

(C) Object of the Invention The object of the present invention is to provide a fixing type heat-sensitive recording material which develops color with a high p-density during heat-sensitive recording and has excellent storage stability.

(To) Structure and operation of the invention In other words, the fixing type heat-sensitive recording material of the present invention has a diazonium salt, a coupler compound, a color forming aid, and a color developer formed on a support by an organic compound that is melted under heat and exhibits a basic atmosphere. Fine particle dispersion of basic compound? A fixing type heat-sensitive recording material provided as a light- and heat-sensitive layer in the same layer or in two or more separate layers is characterized by using a compound represented by the following general formula (I) as a coloring aid.

General formula (I) (wherein R represents an alkyl group or an aralkyl group, and n represents an integer of 1 to 3) The compound used in the present invention is a solid at room temperature with a melting point of 40 to 160°C, preferably 70 to 135°C. It is preferable to use a substance that is sparingly soluble or insoluble in water, and that easily dissolves the diazonium salt, coupler compound, and organic basic compound used as a color developer when hot melted.

Specific examples of compounds used in the present invention are shown in Table 1, but the present invention is not limited thereto.

Table 1) Enal The above compounds used as color development aids in the present invention are all thermofusible, water bathable or insoluble, and are used in the form of fine particles with a particle size of 0.1 to 10μ. . The ratio of diazonium salt, coupler compound, and coloring aid of the present invention is 1:
(0,1-10): The range of (0,1-20) (weight) is preferable. Further, the coloring aids can be used alone or in combination of two or more of them if necessary.

The effect of improving the color development sensitivity of a fixable heat-sensitive recording material by the color development aid of the present invention is observed not only when hydrophobic guanidine/derivatives but also widely known organic basic compounds are used as a color developer. Preferred organic basic compounds include the following guanidine/derivatives.

General formula (iI) 几5 General formula (2) (wherein R1, R2, R5, R4 and R5 are hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino , all heterocyclic residues are represented, R6 is lower alkylene/, phenyle/, su7tile/, or ÷X÷ (in the formula
represents a lower alkyl/, so2, R2, s, o, -NH- or -heavy bond 7), and the aryl group in the formula represents a lower alkyl, alkoxy, nitro, acylamino, alkylamino group and halogen. It also includes those having a substituent r. ) The diazonium salt used in the present invention may be a compound used in conventionally known diazo type copying materials. Although it can be used arbitrarily, for example, the following general formula (good), (V), (
What is indicated by (to)? It can be used particularly preferably.

(IV) Ynl 1r (I In the formula, 几7 and R8 are alkyl having 1 to 5 carbon atoms, alkoxyl, oxyalkyl, benzyl, substituted benzyl, be/diyl, substituted benzoyl, phenyl group, hydrogen atom, etc. , Y and 2 are halogen atoms, carbon number 1-
5 alkyl, carboxy/L', alkoxyl having 1 to 5 carbon atoms, nitro, acetoxy group, etc., m and n are 0 or a positive integer of 4 or less. Also, X is O4-, B
r-, 804-, NO5-PF, l-1Ot04miB
Anions such as F4- and further znct2.0nOt2$
8nOt4, etc. represent ions added to these anions.

Specific examples include 4-N,N-dimethylaminebenzenediazonium chloride, 3-chloro-4-N.

N-diethylaminobenzenediazonium chloride, 4
-N, N-diethylaminobenzenediazonium chloride, 2,5-jethoxy-4-N, N-diethylaminobenzenediazonium chloride, 4-N-ethyl-N-hydroxyethylaminobenzenediazonium chloride, 4-N, N-jethoxy Toxiaminobenzenediazonium chloride, 4-phenylaminobenzenediazonium chloride, 4-N-(P-methoxyphenyl)
-aminobenzenediazonium chloride, etc.

In the formula, R9 is -0H20H200H20H2- or -0H2
00H20H2-1-OH20H20H20H2-, etc. X, Y, Z, m and n have the same meanings as in the general formula (transformation).

Specific compound examples include 4-morpholinobenzenediazonium chloride, 2,5-jethoxy-4-morpholinobenzenediazonium chloride, 4-oxacyridinobenzenediazonium chloride, 3-methyl-4-
Examples include piperidinobenzenediazonium chloride.

n In the formula, RlG represents an alkyl group or an aryl group. or,
X, Y, Z, m and n have the same meanings as in the general formula (transformation).

Specific compound examples include 4-ethylmercapto-2,
Examples include 5-jethoxybenzenediazonium chloride, 4-tolylmercapto-2,5-diethoxybenzenediazonium chloride, and 4-benzylmercapto-2,5-jethoxybenzenediazonium chloride.

These diazonium salts are dissolved in water or an organic solvent, or dispersed in fine particles in a suitable solvent, preferably at a concentration of 0.1
~1. Of/rr? It can be coated on the support within the range of .

In addition, an acid compound can be used in the photosensitive and thermosensitive layer to stabilize the diazonium salt and prevent pre-coupling.
Any organic or inorganic acid compound used in conventionally known diazo type copying materials can be used. Specific examples include tartaric acid, citric acid, boric acid, lactic acid, gluconic acid, phosphoric acid, trichloroacid, etc. Acetic acid, dichloroacetic acid, cyanoacetic acid, oxalic acid, malonic acid, maleinoic acid, etc. are all preferably used.

The weight ratio of these acid compounds to the organic basic compound is preferably 5.0 to 10 (l), more preferably 10 to 50%.

Further, as the coupler compound which reacts with the diazonium salt to form an azo dye, any compound capable of coupling with the above-mentioned diazonium salt can be used. Examples of these coupler compounds include phenol derivatives, oxynaphthalene derivatives, compounds containing active methylene groups, and heterocyclic compounds. Specific examples of these compounds include the following compounds.

Phenol derivative pyrocatechol resorci/phloroglycine pyrogallol meta-aminophenol para-aminophenol diethylaminophenol N-lauryl-para-aminophenol N-acyl-meta-aminophenol 3,3',5-)lyhydroxydiphenyl 3,3'
, 5,5'-tetrahydroxydiphenyl α-resorcinic acid β-resorcinic acid γ-resorcinic acid phloroglucinic acid gallic acid oxynaphthalene derivative 2,3-dihydroxynaphthalene β-7tol α-naphthol 1,6- Dihydroxynaphthalene 2,3-dihydroxynaphthalene-6-sulfonic acid 2-
Naphthol-3,6-disulfonic acid 1,8-dihydroxynaphthalene-8-sulfo/acid 2-hydroxy-3-naphthoem-NlN-bis-β-hydroxyethylamide 5-(paranitro)-benzamide-1-naphthol 1
-+7)-3-(N-β-Hydroxyethyl)-sulfone-amide 2-H-7-3-propylmorpholinonaphthoic acid 2-hydroxy-3-naphtho-0-toluidide 2-hydroxy-3- Naphthoic acid morpholinopropylamide 2-
Hydroxy-3-naphthoe@-i'-chloroanilide 2
-Hydroxy-3-naphthoic acid-2',5'-dimethoxyanilide 2-hydroxy-3-naphthoic acid-2'-ethoxyanilide 2-hydroxy-3-su7): rJR-
2'-methoxyanilide 2-hydroxy-3-naphthoic acid phenyl ester 2-hydroxy-3-naphthoic acid
4'-phenoxyanilide 2-hydroxy-3-naphtho#-4=benzyloxy7anilide 2-hydroxy-3-
Nando 4-4'-7enethyloxyanilide 2-hydroxy-3-naphtho-'! -2'-pendeloxyanilide Compound with active methylene group 1-phenyl-3-methyl-pyrazolone (5) Acetoacetic acid anilide 1-phenyl-3-carboxypyrazolone Acetoacetic acid Cyclohexylamide acetoacetic acid Dobe/Dylamidocyanoacetanilide Cyanoacetomorpholine 4-carboxy-acetoacetanilide Heterocyclic compound 1-(4'-carboxyethylphenyl)-3-dodecyl-pyrazolone-5 These Kabra compounds are dissolved in water or an organic solvent. Dissolve and
Alternatively, it can be contained in the light and heat sensitive layer as a fine particle dispersion with a particle size of 10 μm or less using a dispersion means such as a ball mill or a sandog 2-I/dar attritor.

Also, is the Kabra compound two or more compounds as necessary? Desired spectral absorption characteristics in combination? The dye combinations shown may be produced. Also, when dispersing, use a coupler.
Although the compound may be dispersed alone, it can also be co-dispersed with an organic basic compound, the color development aid of the present invention, 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.
If the solubility is 1.0 t/ or less, the humidity and heat storage stability is good, and heterocyclic compounds such as aliphatic amines, pyrrolidine derivatives, imidazole derivatives, imidacillin derivatives, and piperidine/derivatives can also be suitably used. However, especially when used as a total color developer for hydrophobic guanidine-containing compounds of the following general formulas (II) and (2), it is a fixing agent that has excellent storage stability under high temperature and high humidity conditions and that develops color with high sensitivity. type thermosensitive recording medium can be obtained. In addition, the color developer has a melting point of 100 to 17
A temperature range of 0° C. can be particularly preferably used.

The color developer may be dispersed alone using a dispersion means such as a ball mill, sand grinder, or attritor, but it may be co-dispersed with a turntable compound, the color development aid of the present invention, or other necessary additives. Good too.

General formula Qll) [In the formula, R1, 几2, 几3, R4 and fused are hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, and heterocyclic residues. and R6 represents lower alkylene, phenylene, naphthylene/, or uX÷ (in the formula, X represents lower alkylene/, so2, s2.s, 0, -NH-, or - double bond), and the aryl group in the formula also includes those containing substituents selected from lower alkyl, alkoxy, nitro, acylamino, alkylamino groups, and hachigen.] Typical specific examples thereof are shown in Table 2, but these hexyl groups? represent.

Table-2 H5 (7) σNH-0-NH0 (8) σNH-0-NHω 1; (9) an3o<ΣNH-c-NH000H5Hs J O2 LJH3NHun3 OH,0O-NH (OH2)2 (OH2)4 NH2- 0-NH2 NH2-0-NH2 These guanidine derivatives shown above can be easily synthesized by a known method or a method similar thereto.

Further, examples of the binder material for forming the photosensitive heat-sensitive tit of the present invention include cornstarch, gum arabic, glue, gelatin, casein, methyl cellulose, and ethyl cellulose in aqueous solvents.

Hydroxyethyl cellulose, carboxymethyl cellulose, polyacrylamide, carboxymethyl de/gun, dialdehyde starch and other modified products and fermentation derivatives thereof, polyvinyl alcohol or modified products and derivatives thereof, polyvinylpyrrolidone, isobutylene-maleic anhydride copolymer polyacrylate, styrene-maleic anhydride copolymer, polyvinyl chloride, polyvinyl chloride IJ den, polystyrene, styrene butadiene/rubber (=
SBR), methacrylate butadiene rubber (=MBJ,
Synthetic resin emulsions such as nitrile ptadiene/rubber (=NBJ polymethyl methacrylate, polyglopyre/, polyacrylonitrile, acrylic ester, etc.) can be mentioned, and these binder materials can be used alone or in combination.In addition, in organic solvent systems, The above synthetic resin gold can be used by dissolving it in an organic solvent without emulsifying it.

The Kabbliff reaction of diazonium salts is promoted in polar solvents such as water, so the storage stability of fixed heat-sensitive recording materials using diazonium salts, especially under high temperature and high humidity conditions, is reduced to a low equilibrium moisture content! When using an aqueous solvent, a water-soluble polymer binder such as formalin, glyoxal, chromium alum, gel tar aldehyde, melamine/formalin resin, urea/formalin resin etc. Storage stability can also be improved by using water-resistant agents used in materials.

Further, specific examples of pigments used in the light-sensitive and heat-sensitive layer of the present invention include kaolin, calcining powder, talc, waxite, styrene resin particles, calcium carbonate, aluminum hydroxide, magnesium hydroxide, and carbonic acid. Examples include magnesium, 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 sticking, JP-A-53-118059 and B4-258 are used.
45.54-118846. An oil-absorbing pigment with an oil absorption of 80-500m//100f according to the measurement method specified in JIS K 5101 as described in 54-118847 publication?
! - It is desirable to use oil-absorbing pigments, such as calcined kaolin, urea-formalin fillers, etc., which exhibit the above-mentioned oil absorption amount, especially in layers that are in direct contact with the thermal head.

Other auxiliary ingredients include zinc chloride, zinc sulfate, sodium citrate, guanidithiourea sulfate, calcium gluconate, sorbitol,
Saccharides such as saccharose are used, and any necessary ultraviolet inhibitors may be added, and waxes and metal soaps may be used for the purpose of improving sticking and coloring sensitivity.

Specifically, waxes include paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty acid amides such as stearic acid amide, lauryl amide, myristyl amide, hardened tallow acid amide, palmitic acid amide, and olein. Examples include acid amide, acetamide, coconut fatty acid amide, methylolated products of these fatty acid amides, methidi/bisstearamide, ethylenebisstearamide, and higher fatty acid esters.

Examples of metal soaps include polyvalent metal salts of higher fatty acids, ie, zinc stearate, aluminum stearate, calcium stearate, zinc oleate, and the like.

These can be used alone as dispersed, but they can also be used as co-dispersed with organic basic compounds, coupler compounds, etc., and the color development aid of the present invention.

In addition to paper, synthetic resin films, laminated paper, etc. can be used as the support. When paper is used as a support, if the photosensitive and heat-sensitive layer is applied directly onto the support, the diazonium salt will fill the voids in the paper base. Since a large amount of diazonium salt is required to penetrate and impregnate the inside, the sensitivity of light fixing by exposure after thermal printing may decrease. Humid silica sol,
The entire photosensitive and heat sensitive layer may be precoated with a porous photosensitive agent such as alumina, titanium oxide, or kaolin, or a combination of these and a polymeric material such as starch, casein, polyvinyl alcohol, or polyvinyl acetate emulsion.

(E) Examples Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 A coating solution for a light and heat sensitive layer was prepared with the following formulation, and the coating amount after drying on a support was 9. A fixing type heat-sensitive recording material is prepared by applying the mixture so that it is of/- and drying it.

The unit is parts by weight.

Incidentally, liquids A and B were prepared by pulverizing and dispersing them for 48 hours in the following compounding T-ball mill.

Solution A Example 2 In Example 1, ethylene glycol bis(P-
Benzyloxycarbonylphenyl) ether and diethylene glycol bis(p-beyzyloxycarbonylphenyl) ether to be used in Group 9? Example 1 except for the use
A fixed thermosensitive recording body sound was created in the same manner as above.

Example 3 The procedure was repeated in the same manner as in Example 1, except that 2-hydroxy-3-naphthoic acid-2'-ethoxyanilide was used instead of 2-hydroxy-3-naphthoic acid-2'-ethoxyanilide in Example 1. A fixable thermosensitive recording material was created.

Comparative Example 1 A fixable heat-sensitive recording material was prepared in the same manner as in Example 1 except that the ethylenoglycol bis(P-benzyloxycarbonylphenyl) ether of the present invention was removed from Liquid A in Example 1.
Created.

A fixed heat-sensitive recording material obtained in this way? After thermal printing was carried out using a facsimile machine (Toshiba KB-4800), the diazonium salt 7 was decomposed and fixed by exposing the entire surface to ultraviolet light.

The print density meter Macbeth densitometer (R
D=514). The values are shown in Table 3. Table 3 also shows the results of the storage stability test.

The storage stability test is shown above as a result of a humidity and heat resistance test when the sample was prepared by applying and drying the coating solution and left in a dark place at 40℃ and 90% relative humidity for 24 hours.After the test, the entire surface was exposed to light. Established and measured with Macbeth densitometer I
ll:, the concentrations are shown in Table 3.

Example 4 A layer containing a diazonium fundamental tone was prepared with the following formulation, and the coating amount after drying on the support was 2. +1/? Apply so that it becomes F1''.

Citric acid 2fthiourea 2t2.5-jethoxy-
4-morpholinobenzene 2゜diazonium tetrafluoroborate calcined kaolin
4t10% polyvinyl alcohol
30f water
100 - Prepare fc with the following formulation on the layer created above.
The total coating amount of the layer containing the M colorant after drying is 8°O
A fixing type heat-sensitive recording material is prepared by coating the film in such a manner that the film and film are mixed with each other.

Water 100f calcined Kaori/209'A liquid
52B liquid
100f10 Tivoli Vinyl Alcohol
120f 50% melamine-formalin based water resistant agent 21 In addition, liquid A and liquid B are the same formulation as Example 1.
It was prepared by pulverizing and dispersing it in a ball mill for 48 hours.

Example 5 In Example 4, seven fixing type thermosensitive recording bodies were prepared in the same manner as in Example 4, except that the formulations of liquid A and liquid B were the same as in Example 2.

Example 6 In Example 4, a fixed heat-sensitive recording body sound was prepared in the same manner as in Example 4, except that the compositions of liquid A and Bi were the same as in Example 3.

Comparative Example 2 A fixable heat-sensitive recording material was prepared in the same manner as in Example 4, except that the formulations of liquid A and liquid B were the same as in comparative example 1.

The thus obtained diazo-fixed heat-sensitive recording material was used for thermal printing on a whole facsimile machine (Toshiba KD-4800)', and then the diazonium salt was decomposed and fixed in an ultraviolet exposure source over the entire surface.

The print density obtained as described above was measured using a total Macbeth densitometer (R
D-514) and the values are shown in Table 4.

Table 4 also shows the results of the storage stability test.

Is the storage stability test for coating liquid? After preparation, the samples were coated and dried, and the results of a heat resistance test were shown, in which the sample was left in a dark place at a temperature of 40℃ and a relative humidity of 90℃ for 24 hours, and a heat resistance test was conducted in which the sample was left in a dryer for 24 hours at a temperature of 60℃, respectively. After processing, the entire surface was exposed to light and fixed, and the background density measured with a Macbeth densitometer is shown in Table 4.

Table 4 (F') Effects of the Invention As shown in Tables 3 and 4, the compound represented by the general formula (I) of the present invention? By adding it to a fixing type heat-sensitive recording material, it was possible to obtain a fixing type heat-sensitive recording material that developed color at high density and had excellent storage stability.

Claims (1)

[Scope of Claims] 1. A fine particle dispersion of a diazonium salt, a coupler compound, a coloring aid, and an organic basic compound that melts with heat and exhibits a basic atmosphere as a color developer in the same layer or in two or more layers. In a fixing type heat-sensitive recording material provided on a support as a light- and heat-sensitive layer consisting of another layer, the coloring aid is expressed by the following general formula (
A fixable heat-sensitive recording material characterized by being a compound represented by I). General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R represents an alkyl group or an aralkyl group, and n represents an integer from 1 to 3) 2. At least one of a diazonium salt or a coupler compound 2. The fixable heat-sensitive recording material according to claim 1, wherein the light-sensitive and heat-sensitive layer contains a dispersion of discontinuous fine particles. 3. The organic basic compound has the following general formula (II) or (III)
The fixable heat-sensitive recording material according to claim 2, which is a hydrophobic guanidine derivative represented by: General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ General formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, R_3, R_4 and R_5 are hydrogen, carbon atoms with 18 or less Represents alkyl, cyclic alkyl, aryl, aralkyl, amino, alkylamino, acylamino, carbamoylamino, heterocyclic residue, R_6
represents lower alkylene, phenylene, naphthylene, or ▲Mathematical formula, chemical formula, table, etc.▼ (in the formula, X represents lower alkylene, SO_2, S_2, S, O, -NH-, or a single bond), Groups include those having substituents selected from lower alkyl, alkoxy, nitro, acylamino, alkylamino groups and halogen. )