JPS59202891A - Manufacture of heat-sensitive recording body - Google Patents

Abstract

PURPOSE:To attempt prevention of fogging phenomenon, by, in manufacture of heat-sensitive recording body of light-fixing property, coating a carrier body with aqueous coating liquid containing more than at least one kind of diazo-compound, coupler and specified amide-compound and also, more than one kind of the specified compound. CONSTITUTION:An aqueous coating liquid is manufactured by combining more than at least one kind of diazo-compound, coupler and metallic soaps represented by formula I or formula II (where, R1-R3 represent alur-radical that may be replaced by saturated or unsaturated alkyl-group of C5-C23, alkyl-group, etc. or Halogen atoms respectively, m=1 or 2) and formula III (where, R4 represents saturated or unsaturated alkyl-group of C4-C23, n=2 or 3, M divalent or trivalent metallic ion). By this method, unnecessary color forming phenomenon can be eliminated during the course of manufacture of the aqueous coating liquid and coating of this on the carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a heat-sensitive recording material, and particularly to a method for producing a heat-sensitive recording material that can be photofixed.

Conventionally, heat-sensitive recording materials that utilize the coloring reaction of a basic colorless dye and a coloring agent that can develop a color when brought into contact with the colorless dye, and obtain a recorded image by bringing both coloring substances into contact with each other using heat, have been widely used. Are known.

Since such heat-sensitive recording media are configured to obtain a recorded image using heat, if the heat source is mistakenly brought close to the recorder even after the heat-applied record has been made, the entire heat source will develop color, making the necessary record unreadable. It has defects. Therefore, it has been difficult to apply it to important records that require preservation.

Therefore, in recent years, development of a diazo-based heat-sensitive recording material that utilizes a color-forming reaction between a diazo compound and a coupler has been progressed as a fixable heat-sensitive recording material.

Generally, in such diazo-based heat-sensitive recording materials, a coloring aid that generates alkali upon heating is used.
For example, when ammonium salts such as ammonium carbonate and ammonium benzoate, urea, sodium trichloroacetate, etc. are used, the coloring temperature is as high as 150 to 200° C., which causes defects that are not suitable for high-speed recording. In order to enable color development at low temperatures, it has been proposed to use higher fatty acid amides or metal soaps in combination with these, but this causes unnecessary color development during the process of coating the support as an aqueous coating solution. (fogging phenomenon) is easy, and satisfactory results have not been obtained. It is conceivable to use a solvent-based coating liquid to prevent the fogging phenomenon, but this poses a risk of fire and health problems, and is also extremely costly.

In view of the current situation, the present inventors have developed a fixable diazo thermosensitive recording material that can form a recorded image of high density in a temperature range of about 50 to 150°C without the above-mentioned drawbacks. As a result of intensive research, we found that when an amide compound with a specific structure and a water-insoluble fatty acid metal soap with a specific structure are used in combination, the fogging phenomenon does not occur as in conventional methods even with aqueous coating fluids. The present inventors have discovered that a diazo thermosensitive recording material having excellent low-temperature sensitivity can be obtained, and have achieved the present invention.

The present invention provides an aqueous coating liquid containing at least one or more diazo compounds, couplers, amide compounds represented by the following general formula CI) or (II), and one or more compounds represented by the following general formula (III). This is a method for producing a heat-sensitive recording material, which is characterized by coating a support on a support.

R1-CON I(2...CI)R,-CO
NH-(CH2)□-N HCOR9...[■](R
ヰ COO＞□M ・・・・・・ CI,)
[In the formula, R1 and R21R3 each represent a C5' to C23 saturated or unsaturated alkyl group, or an aryl group optionally substituted with an alkyl group, an alkoxyl group, an aralkyl group, or a halogen atom, and m is 1 or 2 shows,
R4 represents a C4 to C13 saturated or unsaturated alkyl group, n represents 2 or 3, and M represents a divalent or trivalent metal ion. ] The above general formula used in the present invention (]
) or (III), for example, methylene bisstearamide, ethylene bisstearamide, caproic acid amide, enanthamide, caprylic acid amide, pelargonic acid amide, undecanoic acid amide, laurin. Examples include acid amide, tridecanoic acid amide, myristic acid amide, pelargonic acid amide, palmitic acid amide, heptadecanic acid amide, stearic acid amide, oleic acid amide, elaidic acid amide, linoleic acid amide, behenic acid amide, benzyl amide F, and the like.

Further, as specific examples of the compound represented by the general formula (III), for example, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, tridecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecane Zinc, magnesium, lead, fatty acids such as palmitic acid, heptadecanoic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, stearolic acid, behenic acid, etc.
Examples include metal soaps such as calcium, barium, aluminum, iron, nickel, cobalt, and copper, and among these metal soaps, calcium, aluminum, and zinc metal soaps are particularly preferably used in the present invention.

In addition, in the present invention, general formula [I] or (
The amide compound represented by n) and the metal soap represented by the general formula [■] are always used in combination, and the desired effect of the present invention cannot be obtained even if either is used alone.

Therefore, the proportion of such amide compound and metal soap used in combination is
Although it is not specified in -II as it varies depending on the compound used, it is generally 0 for 1 part by weight of the amyl' compound.
．． It is desirable to use metal soap in an amount of about 1 to 20 parts by weight, more preferably about 0.5 to 10 parts by weight.

The coloring aid used in the present invention, which is composed of an amide compound and a metal soap, is generally 0.1 to 20 parts by weight, more preferably 1 to 10 parts by weight, per 1 part by weight of the diazo compound. desirable.

Various materials are known as diazo compounds that are used in combination with such specific coloring aids, but in the present invention,
In particular, it is desirable to selectively use a diazonium salt having a solubility in water of 0.01% by weight or less. Examples of such diazonium salts include p-N,N-dimethylaminobenzenediazonium, 4-morpholino-2,5-dibutoxybenzenediazonium, and 4-(4-methoxy)-benzylamino-2,5-jethoxybenzenediazonium. , 4-morpholinobenzenediazonium, 4-pyrrolidino-3-methylbenzenediazonium, P-N-ethyl-N-hydroxyethylanilinediazonium, 4-
Tetraphenyl boron salts, phosphorus hexafluoride salts such as benzamide-2,5-jethoxybenzenediazonium, 2-N,N-diethyl-m-)luidine diazonium, and 6-morpholino-m-1-luidine diazonium. Examples include.

The coupler is not particularly limited, and various known materials can be used as long as it forms an azo dye by coupling with a diazonium salt in a basic atmosphere. Specifically, for example, resorcinol, catechol, phloroglucin, α-naphthol, 1,5-di-hydroxynaphthalene, 2,5-dimethyl-4-morpholinomethylphenol, 1-hydroxynaphthalene-
Sodium 4-sulfonate, N-(3-morpholinopropyl)-3-hydroxy-2-naphthamide, 2-hydroxy-3-(β-hydroxyethylamide carbonyl)naphthalene, 2-hydroxynaphthalene-3-carbonyljetanolamine , 2-hydroxynaphthalene-
Sodium 3,6-disulfonate, acetanilide, 3
-Methyl-5-pyrazolone, -Phenyl-3-methyl-5-pyrazolone, 2-hydroxy-3-naphthoic acid-β-naphthylamide, 2-hydroxy-3-naphthoic acid-hydroxyethylamide, 2-hydroxy-3- naphthoic acid amide, 2-hydroxy-3-naphthoic acid-m
-Nitrohenzamide, 2-hydroxy-3-naphthoic acid-p-chlorobenzamide, 2-hydroxy-3-naphthoic acid-〇-ethoxybenzamide, 2-hydroxy-3-naphthoic acid-2,5-dimethoxybenzamide, etc. Images of arbitrary tone can be obtained by mixing one or more of these.

Note that the proportion of the diazonium salt and the darkened coupler can be selected as appropriate depending on the materials used.
Generally, it is appropriate to use 0.1 to 10 parts by weight of a puller per 1 part by weight of diazonium salt.

Thus, in the present invention, an aqueous coating liquid containing at least one of a diazo compound, a coupler, a specific amide compound such as those mentioned above, and a metal soap is prepared. In the liquid, if necessary, preservability improvers such as sodium naphthalene sulfonate, sodium naphthalene disulfonate, sulfosalicylic acid, magnesium sulfate, and zinc chloride, antioxidants such as thiourea and urea, citric acid, malic acid, Acid stabilizers such as tartaric acid, phosphoric acid, saponin, starch, casein, gum arabic, polyvinyl alcohol, polyvinyl acetate emulsion, various adhesives such as SBR latex, as well as silica, clay, barium sulfate, titanium oxide, calcium carbonate, etc. Pigments and the like are appropriately blended.

The aqueous coating solution thus prepared is coated onto a suitable support such as paper, plastic film, synthetic paper, metal film, etc., but there are no particular limitations on the coating method. 3 to Log/rr on dry weight using a suitable coating device such as an air knife coater, roll coater, or blade coater according to a conventional method.
It is coated and dried to about F.

Thus, according to the method of the present invention, in the process of preparing an aqueous coating liquid and the process of coating it on a support as in the conventional method,
A heat-sensitive recording material with extremely high commercial value can be efficiently obtained without causing unnecessary coloring phenomena. Furthermore, the obtained recording material has excellent low temperature sensitivity and is a heat-sensitive recording material suitable for high-speed recording devices.

In addition, in the recording material obtained by the method of the present invention, a recorded image is formed using a thermal pen, a thermal head, etc. in the same way as a normal heat-sensitive recording material, and then the entire surface is irradiated with ultraviolet light using a fluorescent lamp, a mercury lamp, etc. , a recorded image can be fixed by decomposing unreacted diazonium salt in the non-recorded area.

The present invention will be described in more detail with reference to Examples below, but it is of course not limited thereto.

Further, unless otherwise specified, parts and % in the examples indicate parts by weight and % by weight, respectively.

Examples 1 to 10 Ten types of aqueous coating liquids were prepared by blending the coloring aids shown in Table 1 based on the composition table below, and after pulverizing each in a ball mill for 48 hours, using a wire bar. Dry coverage of 7 g/r on 49 g/rrr high quality paper
The coating was coated and dried to obtain a heat-sensitive recording material.

Water 40 parts Polyvinyl alcohol 10% aqueous solution 15 parts 2-Hydroxy-3-naphthoic acid-0-ethoxybenzamide
4 parts particulate silica
4 parts coloring aid
4 parts 4-morpholino-2,5-dibutoxybenzenediazonium tetraphenylboron 1 part Comparative Example 1 In Example 1, 4-morpholino-2,5-dibutoxybenzenediazonium tetraphenylboron (solubility in water 0% by weight) instead of 4-morpholino-2,
A thermosensitive recording material was obtained in the same manner as in Example 1, except that 5-dibu1-xyhenzendiazonium tetrafluoroborate (solubility in water: 0.04 i% by weight) was used.

Comparative Example 2 A thermosensitive recording material was obtained in the same manner as in Example 1 except that calcium stearate constituting one of the coloring aids was not used.

Comparative Example 3 A thermosensitive recording material was obtained in the same manner as in Example 1, except that stearic acid amide constituting one of the coloring aids was not used.

With the 13 types of heat-sensitive recording material numbers obtained in this way (G),
The fog on the surface of the recording layer at room temperature and the color density of the recording material after being left at 100°C for 5 seconds were measured using a Macbeth densitometer (yellow filter), and the results are also listed in Table 1. .

In addition, when the obtained heat-sensitive recording material was recorded with a hot pen, a hot knife, etc. by the usual method, and Shiyu (when the entire surface was irradiated with light, the unreacted diazonium salt in the non-recorded part was decomposed and the A well-established record image was obtained.

As is clear from the results in Table 1, all the thermosensitive recording materials obtained in the Examples of the present invention were free from fog and exhibited excellent color density.

Patent applicant Kanzaki Paper Co., Ltd.

Claims (2)

[Claims] (1) An aqueous coating liquid containing at least one diazo compound, coupler, one or more amide compounds represented by the following general formula] or (II), and one or more compounds represented by the following general formula (DI). A method for producing a heat-sensitive recording material, which comprises coating it on a support. R, -CON H,... (1) R2CON
H(CHt), IIN HCOR3...(II)(
R4CoO) nM ...... (III
) [In the formula, R1+ R2HR3 each represents a C to C2 di saturated or unsaturated alkyl group, or an alkyl group, an alkoxyl group, an aralkyl group, or an aryl group optionally substituted with a halogen atom, and m is 1 or 2, R represents a saturated or unsaturated alkyl group from C to G2B, n represents 2 or 3, and M represents a divalent or trivalent metal ion. ] (2) The solubility of the diazo compound in water is 0.01
Claim No. (1) which is a diazonium salt of not more than % by weight
2. Method for producing a heat-sensitive recording medium as described in Section 1.