JPS58212983A - Light fixing type heat sensitive recording medium - Google Patents

Abstract

PURPOSE:To obtain a light fixing type heat sensitive recording medium by which highly sensitive thermal recording can be performed, which has excellent preserving stability, and wherein diazonium salt, a coupler, and a basic material, which are insoluble or hard to dissolve in water, are provided in a base body in a fine particle state together with a binder. CONSTITUTION:Diazonium salt (e.g. p-N, N-dimethylaminobenzene diazonium or the like), which is insouble or hard to dissolve in water; a coupler (e.g. o- hydroxydiphenyl or the like), which is insoluble or hard to dissolve in water, and a basic material (e.g. 1,3-diphenylguanidine or the like), which is insoluble or hard to dissolve are dispersed in water. The dispesed liquids are mixed. Then a binder (e.g. PVA or the like) is added as required, and a paint is prepared. Then the paint is applied or impregnated to a base body (e.g high quality paper and the like), and an intended light fixing type heat sensitive recording medium is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photofixable thermosensitive recording medium that records by heating and fixes non-recorded areas by irradiating light, and more specifically, it is capable of thermal recording with high sensitivity and is storage stable. The present invention relates to a photosensitive layered thermosensitive recording medium with excellent properties.

Recently, the thermal recording method has been widely used in printers such as 7mm printers due to its advantages such as the ability to make the device smaller and lighter and to perform recording without noise. However, the currently widely used dye-coloring thermal recording paper, which utilizes the reaction between an electron-donating 9/J substance and an electron-accepting substance, is colored by reheating or an organic bath agent, or by using adhesives or cellophane. There was a problem that the tape or the like caused the color to develop or disappear.

There is a thermal recording paper that uses a heat-developable diazo method that solves these shortcomings and is capable of constant uJ performance.1 When this heat-developable diazo paper is used as a heat-sensitive recording paper, recording is first performed using heat. , followed by light fixing. Many proposals have been made for the conventional heat development diazo method, but none have been able to satisfy both the high thermal sensitivity that can be recorded using a thermal head and sufficient storage stability.
It hasn't been made yet.

As a result of repeated research, the present inventors solved the above drawback [7
This led to the invention of a photofixable thermosensitive recording medium that possesses both a high thermal te+ degree and sufficient storage stability. The configuration of the present invention is as follows.

(11) A water-unbathable or water-releasable diazonium salt, a water-unbathable or poorly water-soluble coupler, and a water-unbathable or water-releasable basic substance are formed into fine particles along with a binder on or in the substrate. A light-fixing type heat-sensitive recording medium characterized by its small size.

(2) Water-free 1 with a binder on or in the substrate
! 1. A photofixable heat-sensitive recording medium characterized in that a coupler having a water-soluble or water-soluble diazonium salt and a water-unbathable or water-soluble basic residue are present in the form of fine particles.

(3) The photofixable thermosensitive recording medium according to claim (1), characterized in that a water insolubilizing agent or a water hardly solubilizing agent of a diazonium salt is used.

(4) A water-insolubilizing agent or a water-poorly soluble agent for diazonium salt.

A light-fixing type heat-sensitive recording medium according to claim (2), characterized in that an agent is used.

Most of the conventional heat development diazo methods use diazonium salt,
In order to prevent this, pre-coupling reactions often occur during storage because a small amount of the coupler and basic substances (both components) are provided on the substrate in a commonly understood state. , many attempts have been made, but as a result, the thermal sensitivity has decreased significantly.However, in the present invention, the three components of diazonium salt, coupler and basic substance are used.
All of the components, or the two components of camplar having a diazonium salt and a basic residue, are water-inbathable or water-releasable, and are provided on or in the substrate in a dispersed state.
It has excellent storage stability. Furthermore, since the dispersed particles of each component can be present in close proximity, high thermal sensitivity can be achieved.

Next, each component used in the present invention will be explained.

The water M; s-type or poorly water-soluble diazonium salt used in the present invention is obtained by changing the anion component of a conventionally known diazonium salt to a special anion. All conventionally known diazonium cations can be used, such as C, p-N, N-dimethylaminobenzenediazonium, 4-benzamido-2,5-jethoxybenzenediazonium, 4-morpholino 2.5
- an anion that imparts water-insoluble or water-releasable properties to the 6-diazonium salt such as dibutoxybenzenediazonium; 1. Well, BF4. Tipff-8nF 6+
Z nF 4 * P F 6 * SCN + Phosphotungstate ion, phosphomolybdate ion, arylsulfonate ion, detraphenylboron ion, and analogs thereof, etc. are mentioned.

Here, specific examples of arylsulfonic acid ions are shown below.

Incidentally, the 2,3-dihydroxynaphthalene-6-sulfonic acid ion also has stiffness as a coupler.

Next, the method for synthesizing the water-insoluble or poorly water-soluble diazonium of the present invention including tetrasoenylboron ion and its like is as follows. That is, a water bath solution of a conventionally known water-soluble diazonium salt, such as PN, N-dimethyl γ-minobenzenediazonium chloride zinc chloride, and a compound that liberates the above-mentioned special anion in the water bath solution, such as K P F' ,z
.

Mix and stir the water bath solution. Since the precipitate formed in the water bath solution is the desired water-insoluble or water-releasable diazonium salt, it can be filtered.

As the campler in the present invention, any water-insoluble or poorly water-soluble camplar can be used. For example, 0-hydroxydiphenyl, l-hydroxynaphthalene, 2-hydroxynaphthalene, 2,7-hydroxynaphthalene, naphthol AS1 naphthol As-D, naphthol As-B
Examples include 2-hydroxy-3-naphthoic acid derivatives such as O and the like.

Basic substances that can be used in the present invention include water-insoluble substances that melt, dissolve, decompose, react, etc. when heated, and create a basic atmosphere suitable for the coupling reaction between the diazonium salt and the coupler. Alternatively, one that is poorly water soluble is selected. Examples include organic amines such as distearylamine, nitrogen heterocyclic compounds such as 2-phenylimidazole, guanidine/derivatives, and the like. The guanidine derivative suitable as a basic substance in the present invention is solid at room temperature, preferably has a melting point of 60C or higher, is insoluble or dissolvable in water, and has the following general formula % [where R+, R11 , R31R4, R5 are hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aIJ -
represents an acyl, acylamino, or amino group,
At least one of R11l R31R4 is an aryl group, R6 is lower alkylene, FeniX is lower alkylene, 802. Sg+ S+ o, -NH- or -represents a double bond) 1. , the aryl group in the formula is a compound covered with a substituent selected from a low-y alkyl, alkoxy, nitro, lf-acylaminoalkyl, amino group, and halogen. Specific examples include 1,3-diphenylguanidine, 1,3-cy0-)IJluguanidine, l,3-di-p-methoxyphenylguanidine, l-benzoyl-3-phenylguanidine, 1,2,3-) diphenylguanidino, 1.3
-diphenyl-2-cyclohexylguanidine, 0-tolylbiguanide, p-di(1,3-diphenylguanidino)diphenyl, and di(triphenylguanidino)methane.

A coupler having a basic residue is a substance that has two functions as a coupler and a basic substance, and examples of the water-insoluble or poorly water-soluble substance used in the present invention include ＼CHF.

As the water insolubilizing agent or water msizing agent for diazonium salt,
Substances which liberate the anionic components mentioned in the case of diazonium salts in aqueous solution are used.

For example, HBF4. H2TiF6. H1lS1NF
61 H8ZnF<.

Acids such as HPF6 and their salts, heteropolyacids and their salts such as phosphotungstic acid, phosphomolybdic acid, and silicotungstic acid, thiothia/acids and their salts, arylsulfonic acids and their salts, tetrah-nylporide salts and their analogs. Examples include the body.

Specific examples of arylsulfonic acids and their salts listed as water insolubilizers or water-refractory agents for diazonium salts are shown below.

Specific examples of tetratunyl boron and its analogues mentioned as water insolubilizers or water obscurants for the above-mentioned diazonium salts are shown below.

Each component of the diazonium salt, Kagura-1 basic substance, Kassira having a basic residue, water insolubilizing agent or water obscuring agent for the diazonium salt is selected from the above-mentioned components and used. It is also possible to use two or more species in combination.

Examples of the binder used in the present invention include conventionally known vinyl alcohol, starch, water bathable binders such as isobutylene-maleic anhydride copolymer salt, polyvinyl acetate, polyacrylic acid ester, styrene-butadiene latex, etc. The emul resins of

In addition, in the present invention, pigments such as silica, aluminum hydroxide, aluminum carbonate, antioxidants such as thiourea and ascorbic acid, color development sensitivity and color development speed improvers, and 17 various waxes are used. I can do it.

Substrate in the present invention and 1. In this case, high quality paper, coated paper, art paper, synthetic resin film, woven fabric sheet, metal, glass, etc. can be used.

A method for producing the photofixable thermosensitive recording medium of the present invention will be explained. The diazonium salt, the coupler and the basic substance, or the diazonium salt and the coupler having a basic residue are each dispersed in water alone or as a mixture of two or more components. Dispersion is carried out using various devices such as a ball mill, and various fine dispersants can be used as necessary.

Water-insolubilizing agent or water-difficult agent for diazonium salt, binder,
Pigments and various additives can be added before or after dispersion. The photofixable thermosensitive recording medium of the present invention can be obtained by mixing these dispersions and applying or impregnating a substrate with a coating material prepared by adding a binder if necessary. Although it is possible to provide each dispersion in separate layers, it is preferable from the viewpoint of thermal sensitivity to include all the components in one layer.

Next, the specific production of the photofixable thermosensitive recording medium of the present invention will be explained with reference to Examples.

Example 1 A paint having the following formulation was prepared, applied on high-quality paper with a basis weight (i4.ii, '+') using a wire bar, and dried at 55C.

The dry coating strength was 5.0 g, /-+'.

4-benzamide-2,5-shed 20 parts by weight 20% aqueous dispersion of xybenzenediazonium hexafluoride salt 2-hydroxy-3-naphthoic acid 30 parts by weight - 20% aqueous dispersion of morpholinopropylamide detraphenylboron Sodium 10-layer lid part 10
% water bath liquid 15% water dispersion of fine powder silica 40 heavy lid PVA
35 parts by weight of a 15% water bath solution of 4 (10j
! When 10 il of pressure was applied and pressed to develop color, a deep blue-purple color was formed.

The maximum density at this time was 140, and the coloring temperature was 85C, which was the temperature that gave the maximum density of one point. Also, when recording was performed with a thermal head under the printing conditions of fIj force] city pressure 16v1 pulse width 3.0 m-, the recording density of 1.15 was t.
I got r+. If this light-fixing heat-sensitive self-recording medium is fixed by leaving it on a nail indoors for about 1 hour or by exposing it to light under an ultraviolet lamp for about 10 seconds, the unrecorded area will become almost white, and even if heated again. No color developed. On the other hand, regarding storage stability, unrecorded and unfixed media were allowed to stand for 6 months at 20C and 60% relative humidity, shielded from light, or for 24 hours at 40C, 90% relative humidity, and almost no background fogging was observed. Further, no deterioration in recording characteristics was observed under these storage conditions.

Example 2 Preparation of paint with the following formulation 1. It was coated with a wire bar on high-quality paper with a weight of 64.9/g" and dried at 55C. The dry coating was 115.5117 d.

20% aqueous dispersion of 4-P-methoxy/benzamide-2,5-5-heteroxybenzenediazonium tetraphenyl boron salt Naphthol AS0 20% aqueous dispersion 7'! 11-1
．． 207 parts μ% aqueous dispersion of 3-di-0-tolylguanidine 15% aqueous dispersion of 20101 finely powdered silica in 1 lium of tetraphenylbodine 8 parts i part 15% aqueous solution of starch 8 parts by weight When this light-fixing type thermosensitive recording medium was colored in the same manner as in Example 1, it showed a bluish-purple color with a coloring temperature of 96C1 and a maximum density of 1.30 under heat 4, and a recording density of 1.02 with the thermal head. Obtained. In addition, the storage stability was also good as in Example 1.1 As explained above, the photofixable thermosensitive recording medium of the present invention has both good thermal sensitivity and excellent storage stability, making it extremely practical. It is a photofixable thermosensitive recording medium.

Patent Applicant: Tomoekawa Paper Mills Co., Ltd. Japan'Tunshin Telephone Public Corporation Procedures Amendment (July 10, 1982) - Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of Case Patent Application No. 96175 1988 2 Invention Name of light-fixing thermal recording medium 3 Relationship with the person making the amendment Patent applicant 6 Column 7 “Detailed description of the invention” of the specification subject to the amendment Contents of the amendment Page 10 3 lines from the bottom 1 etc. (2) "20% aqueous dispersion of 4-benzamide-2.5-diethoxy/benzenediazonium hexafluoride" on page 15, lines 1 to 3 was replaced with "4-benzamide-2,5-diethoxy/benzenediazonium hexafluoride". 20% aqueous dispersion of zonium hexafluoride phosphorus salt”.

that's all

Claims (1)

[Claims] <11 Water-insoluble or water-releasable diazonium salt, water-insoluble or water+1, together with a binder on or in the substrate! #
A photofixable thermosensitive recording medium characterized in that a soluble coupler and a water-insoluble or water-releasable basic substance are present in the form of fine particles. (2) Optical fixing characterized in that a coupler having a water-insoluble or water-releasable diazonium salt and a water-insoluble or water-releasable basic residue is present in the form of fine particles together with a binder on or in the substrate. (3) A photofixable thermosensitive recording medium according to claim 1, characterized in that a water insolubilizing agent or a water hardly solubilizing agent of diazonium or salt is used. , ′
−・ ゛Chograph ゛ 〜 ゛・−゛. −°−−−−゛−1 (4) A photofixable thermosensitive recording medium according to claim 2, characterized in that a water insolubilizing agent or a water hardly solubilizing agent of a diazonium salt is used.