JPS60151090A - Diazo thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a diazo thermal recording material comprising a plastic sheet as a base and having sufficient heat response characteristics, a high developed color density and excellent head matching property, by a method wherein a water-soluble resin and a water-insoluble resin are used in combination as a binder for a coupler, and calcium carbonate and silicon oxide are incorporated into a coupler layer as filler. CONSTITUTION:A water-soluble resin and a water-insoluble resin are used in combination as a binder for a coupler layer, and silicon oxide and calcium carbonate are incorporated into the coupler layer as filler. The water-soluble resin and the water-insoluble resin (aqueous dispersion type resin) may be, for example, starch and derivatives thereof, methyl cellulose, polyvinyl alcohol or styrene- acrylic copolymer. Accordingly, particularly heat response characteristics and head matching property are maintained, and water resistance after fixing is markedly enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat-sensitive recording material, and more particularly to a fixable diazo heat-sensitive recording material.

[Prior art]

Conventionally, as heat-sensitive recording materials, there are those that produce heat-sensitive coloring by utilizing the reaction between organic metal salts and reducing agents, and those that produce heat-sensitive coloring by using the reaction between leuco dyes and acidic substances. ing. However, such heat-sensitive recording materials have the disadvantage that recorded images cannot be fixed because they are non-fixable. That is,
In the case of such a non-fixable heat-sensitive recording material, it is possible to perform recording again by performing another heating printing after performing recording once by heating printing.

Therefore, the heat-sensitive recording material described above has low reliability in recording because the information recorded thereon can be falsified later, and is used in fields where reliability is required, such as securities, gift certificates, admission tickets, etc. It could not be applied to recording the necessary matters for certificates, slips, etc. or creating them. In addition, in the case of such recording materials, the temperature is generally 70°C.
When exposed to such an environment, the entire surface becomes colored, causing the problem that records become illegible. In particular, heat-sensitive recording materials that utilize the reaction between leuco dyes and acidic substances have the disadvantage that recorded information is erased when they come into contact with organic solvents or plasticizers in plastics. These drawbacks are due to the fact that these heat-sensitive recording materials are non-fixable.

On the other hand, so-called diazo photosensitive paper, which utilizes the reaction between a diazo compound and a coupler, is widely known as a fixable recording material. In this diazo photosensitive paper, by irradiating the unreacted diazo compound with light after image formation, it can be photodecomposed and fixed.

Conventionally, heat-sensitive recording materials have been known in which the reaction between a diazo compound and a coupler is carried out by heating. This diazo-based heat-sensitive recording material has a heat-sensitive coloring layer containing a diazo compound and its coupler as the main reaction components on a support, and one of the components in the heat-sensitive coloring layer is mixed with discontinuous particles. It is isolated from other components to prevent the color reaction from proceeding. However, all of the conventional ones are still insufficient in terms of storage stability and thermal coloring properties when viewed from a practical standpoint. for example.

In order to obtain products with high shelf life, it has been proposed to form diazo compounds and couplers into discontinuous particles.
In this case, the storage stability is relatively good, but the color development is still unsatisfactory, and images with high color development cannot be obtained by instantaneous heating.

Recently, heat-sensitive recording materials have been adapted to be used as output recording materials for facsimiles, telex machines, electronic computers, medical measuring machines, commuter passes, ticket vending machines, etc.
There is a strong demand for high-speed recording performance. When applied to such uses, conventional products had poor thermal response Jr/I to thermal spatulas 1 to 1, and unsatisfactory matching performance to thermal heads.

〔the purpose〕

The present inventors have developed a plastic sheet 1 that is compatible with high-speed recording, has sufficient thermal responsiveness, has high color density, and has excellent head matching properties, unlike conventionally developed diazo-based thermosensitive recording materials. As a result of intensive research to develop a diazo-based heat-sensitive recording material for commuter passes and train tickets using ~ as a support,
The present invention has now been completed.

13 = [Structure] That is, according to the present invention, a plastic is used as a support, and a diazo layer containing a diazo compound as a main component and a coupler layer containing a coupler as a main component are laminated on the support, and the most layer In a diazo-based heat-sensitive recording material in which a protective layer of a water-insoluble resin is provided, a water-soluble resin and a water-insoluble resin are used together as a binder in the coupler layer, and calcium carbonate and silicon oxide are contained in the coupler layer as fillers. A diazo-based heat-sensitive recording material is provided.

The diazo thermosensitive recording material of the present invention maintains the quality of heat responsiveness and head matching property in particular, and has significantly improved water resistance after fixing (peeling of images and non-image areas due to washing, etc.). Conventional products have the disadvantage that if a water-soluble resin is used to improve head matching properties, water resistance deteriorates, while if a water-insoluble resin is used to improve water resistance, head matching properties deteriorate. It had The present invention uses a water-soluble resin and a water-insoluble resin together in order to improve these head matching properties and water resistance.

In addition, when conventional products use calcium carbonate, which is effective for heat response and water resistance, head matching properties and water resistance deteriorate, whereas silicon oxide is used to improve head matching properties. It had the disadvantage of poor thermal response. The present invention uses silicon oxide and calcium carbonate together in order to improve these thermal responsiveness and head matching properties.

Examples of the water-soluble resin and water-insoluble resin (aqueous dispersion type resin) used in the present invention include those shown below.

Casein, gelatin, starch and its derivatives, carboxymethylcellulose, methylcellulose, ethylcellulose, polyvinyl alcohol, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic emulsion, styrene-acrylic copolymer, styrene-butadiene-acrylic Examples include copolymers.

In the present invention, the weight blending ratio of these water-soluble resins and water-insoluble resins is water-soluble resin/water-insoluble resin=]10.5 to
The range is 1710, preferably 171-115. If the blending ratio of the two deviates from this range, the desired objectives in terms of both head matching properties and water resistance cannot be sufficiently achieved.

Further, the silicon oxide used as a filler in the present invention has an oil absorption of 200 m Q /]00 g or more, preferably 300 m Q /]000 g or more. When the oil absorption amount is less than 200 m Q /100 g, problems such as sticking, head staining, tailing, etc. will occur. Moreover, the particle size of this silicon oxide is generally 0.
It is in the range of 01 to 5μ. Calcium carbonate has an average particle size of 0
．． 01 to 10μ, preferably average particle size 0.05 to 10μ
It is in the range of 5μ. When the particle size is larger than this range,
This causes problems such as wear of the thermal head and insufficient thermal response. In the present invention, the weight mixing ratio of these fillers is in the range of calcium carbonate/silicon oxide=10/1 to 1/2, preferably in the range of 5/1 to 1/1.

If the blending ratio of the two deviates from this range, sufficient effects will not be obtained in terms of thermal response, head matching properties, and water resistance.

Next, the basic thermosensitive color forming layer forming material used in the present invention will be explained in detail.

Are you talented in this invention? The diazo compounds and couplers used in this process are those commonly used in diazo-sensitive papers, and include, for example, those shown below.

Diazo Compound: As the diazo compound used in the present invention, commonly used ones, such as those represented by the following general formula, can be used.

R1 8- However, in general formulas [■], [IT) and [■], %R
,,R6,R6 are hydrogen, halogen, C1 to C5 alkyl group or alkoxyl group, or R1,,R,2:
Same as R, 2), R2, R3 are hydrogen, halogen, C1~
C5 alkyl group or alkoxyl group, R4,, R
5 is the same or different C□ to C5 alkyl group, hydroxyalkyl group, C3 alkyl group or alkoxyl group, or halogen), R7 is hydrogen, halogen, trifluoromethyl group, C1 to C5 alkyl group, or Aji), M,, M2. M3 is an acid residue or an acid residue forming a double salt with a metal salt. In this case, the acid residue is preferably a halogen ion or a fluorine-containing inorganic acid ion such as BF-4 or PF-6, while the metal salt that forms a double salt with the acid residue is For example, ZnCQ 2 ,
Examples include CdCQ 2 and SnCQ 2. Y is -C
Represents H2- or -〇〇-, and n is 0 or 1.

Specific examples of those corresponding to general formula (1) include the following.

Specific examples of those corresponding to the general formula [■] include the following.

Specific examples of those corresponding to general formula [1rr) include the following.

In the present invention, in order to obtain a product with further improved long-term shelf life, it is advantageous to use the diazo compound in the form of a water-insoluble salt such as a fluorate-containing salt such as -BF4 or -PF4.

Coupler: 11 Coupler used in the present invention includes phenol, resorcinol, methylresorcinol, 4,4-bisresorcinol,
Phloroglucin, resorcinic acid, phloroglucinic acid, 2
-Methyl-5-methoxy-1,3-dihydroxybenzene, 5-methoxy-1,3-dihydroxybenzene, 4
-N,N-dimethylphenol, 2,6-dimethyl-]
, , 3,5-trihydroxybenzene, 2,6-
Dihydroxybenzoic acid, 2,6-hydroxy-3,5
- Phenol derivatives such as dibromo-4-methoxybenzoic acid, α-naphthol, β-naphthol, 4-methoxy-1-naphthol, 2,3-hydroxynaphthalene, 2
, 3-dihydroxynaphthalene-6-sulfonic acid sodium, 2-hydroxy-3-propylmorpholinonaphthoic acid, 2-hydroxy-3-naphtho-0-toluic acid, 2-
Examples include naphthol derivatives such as hydroxy-3-naphthoic acid morpholinopropylamide, but of course,
The present invention is not limited to these, and any compound that can act as a coupler for the diazo compound may be used.

=12- Thermofusible substance: Examples of the thermofusible substance include the following.

Alcohol derivatives such as 2-tribromoethanol, 2,2-dimethyltrimethylene glycol, and 1,2-cyclohexanediol, acid derivatives such as malonic acid, glutaric acid, maleic acid, and methylmaleic acid, and animals such as beeswax and shellac wax. waxes, vegetable waxes such as carnauba wax, mineral waxes such as montan wax,
Petroleum waxes such as paraffin wax and microcrystalline wax, other synthetic waxes such as polyhydric alcohol esters of higher fatty acids, higher amines, higher amides, condensates of fatty acids and amines, condensates of aromatics and amines, synthetic paraffins, Chlorinated paraffin, metal salts of higher fatty acids, higher linear glycols, dialkyl 3,4-epoxyhexahydrophthalate, N-alkylcarbamoylbenzene, etc.

The thermofusible substance used in the present invention preferably has a melting point or softening point in the range of 50 to 250°C.

If the melting point or softening point is less than 50°C, the shelf life of the product tends to deteriorate, and if it exceeds 250°C, the thermal response of the product to the thermal head becomes unsatisfactory.

In addition, from the viewpoint of obtaining a product with high-speed coloring property (high-speed recording property), these thermofusible substances used in the present invention should be used in an amount of 2 to 30 parts by weight, preferably 5 to 1 part by weight, per 1 part by weight of the diazo compound.
It is used in a proportion of 0 parts by weight. If this amount is less than the above range, color development will be insufficient and the resulting product will be unsuitable as a recording material for high-speed recording.

In the case of the present invention, it is particularly preferable to use 5 parts by weight or more for high-speed output recording such as facsimile. On the other hand, if the amount added is too large, blurring of the image may occur during color development by heating, which is undesirable. Therefore, in the case of the present invention, the amount of the thermofusible substance added is preferably kept within the above range.

In the present invention, a binder is used to firmly support the diazo layer on the support, and examples of such binders include those shown below.

Polyvinyl acetate, polyvinyl chloride, vinyl chloride/vinyl acetate copolymer, polyacrylic ester, polystyrene, polybutadiene, polyacrylamide, styrene/butadiene/acrylic copolymer, styrene/acrylic copolymer, petroleum resin, Polyvinyl alcohol, polyacrylamide, casein, gelatin, starch and its derivatives, polyvinylpyrrolidone, carboxymethylcellulose methylcellulose, ethylcellulose, polyester, polystyrene, chlorinated rubber, styrene-maleic anhydride copolymer, styrene-vinyltoluene copolymer, rosin modification Resin, water-soluble, organic solvent-soluble, or aqueous dispersion type resin such as iso(or diiso)butylene-maleic anhydride copolymer, phenol resin, melamine resin.

The binder used in the present invention has a melting point or softening point of 50
It is preferable to use one having a temperature of 250° C. to 250° C. from the viewpoint of obtaining a product with rapid color development. Further, the above-mentioned binders can be used alone or in the form of a mixture.

Furthermore, in the present invention, an adhesive layer made of thermoplastic resin or thermosetting resin can be provided between the thermosensitive coloring layer and the integral support 15 in order to increase the binding force.

Examples of the resin in this case include polyolefins, polyvinyl compounds, saturated polyesters, polyurethanes, polyamides, phenol resins, area resins, melamine resins, alkyd resins, unsaturated polyester resins, and epoxy resins.

In the present invention, examples of the water-insoluble resin used in the uppermost layer include polystyrene, polyester, vinyl chloride/vinyl acetate copolymer, styrene/vinyltoluene copolymer, and phenol resin.

The support used in the present invention is made of a plastic sheet,
Those formed from conventionally known plastics such as polyolefin, polyester, polyamide, and polyvinyl chloride are used.

In the present invention, the heat-sensitive color forming layer such as the diazo layer and the coupler layer may further contain an acidic substance as an auxiliary component, if necessary.
Basic substances and other substances can be contained.

16- Acidic substance: An acidic substance is added as necessary to prevent a coupling reaction and for storage stability, and examples thereof include the following.

Tartaric acid, citric acid, boric acid, lactic acid, gluconic acid, sulfuric acid, etc.

Basic substance: A basic substance is added as necessary to cause a coupling reaction during heating, and examples thereof include the following.

Caustic alkalis and alkali carbonates such as sodium hydroxide, calcium hydroxide, potassium carbonate, etc.

Substances that generate basicity when heated include urea, thiourea and their derivatives, alkali salts of trichloroacetic acid,
Ammonium chloride, ammonium sulfate, ammonium citrate, etc.

As other auxiliary ingredients, zinc chloride, zinc sulfate, sodium citrate, guanidine sulfate, calcium gluconate, sorbitol, saccharose, etc. are used to suppress or assist color development.

In order to obtain the heat-sensitive recording material according to the present invention, each layer-forming coating solution is prepared by dissolving or dispersing the above-mentioned layer-forming components in an appropriate solvent, and this coating solution is coated on a support in a multilayered manner, dried, and then The heat-sensitive layer coating solution may be applied at a rate of 1 g/a to 5 g/rrr and dried.

The solvent for dissolving or dispersing the layer-forming components is appropriately selected depending on the properties of the layer to be formed and the purpose of formation. Examples of such solvents include water or an aqueous solvent obtained by dissolving an organic solvent in water, benzene, toluene, xylene, n-hexane, n-hebutane, Schiff [I hexane, kerosene, methyl isobutyl ketone, methyl cellosolve, acetone. , methyl ethyl ketone, dimethyl ether, siloxane, and other nonpolar or polar organic solvents.

〔effect〕

The heat-sensitive recording material of the present invention has excellent water resistance, head matching properties, and thermal responsiveness, and is advantageous in various heat-sensitive recording fields, particularly as ticket paper for commuter passes and train tickets that require high-speed recording. In addition, in the case of the present invention, the characters and images recorded on the surface are formed by heating, and then
Fixation can be achieved by decomposing unreacted diazo compounds with light. Furthermore, the heat-sensitive recording material of the present invention can be applied to recording necessary information on securities, gift certificates, admission tickets, certificates, slips, etc., and for creating them, by taking advantage of its fixing properties. Images obtained using the heat-sensitive recording material of the present invention are tamper-proof +t, and have very high reliability.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. Note that all parts and percentages shown below are based on weight.

Example [Diazo layer liquid] Nistearic acid amide 6 parts Vinyl chloride/vinyl acetate copolymer 5++19- Methyl cellosolve 87 parts The composition described in "2" was dispersed in a ball mill for 24 hours to prepare a diazo layer dispersion liquid.

[Coupler single layer]: Naphthol AS 2 parts N-ocdecylcarbamoylbenzene 2// Calcium carbonate (average particle size 1 μm) 211 silicon oxide (average particle size 1 μm) 0.5// Methyl cellulose 0
．． 5〃 Water 92.011 (No. 2 liquid) Naphthol AS Z part N-octadecylcarbamoylbenzene calcium carbonate l II Silicon oxide Q,5u Polyvinyl alcohol Q,3n Styrene/butadiene/acrylic copolymer emulsion l 77 20- Water 93. 2 parts [Noa liquid] Naphthol AS 1 part N-octadecylcarbamoylbenzene 2.5 parts Calcium carbonate] n Silicon oxide 0.31! Oxidized starch 0.21I Styrene/acrylic copolymer emulsion 1,5tt Water 93!I Above Each composition was dispersed for 24 hours using a ball mill to prepare coupler single-layer dispersions No. 1 to No. 3.

For comparison, the following coupler single-layer solution was prepared.

[Liquid No. 4] Nano 1--L AS 2-part octadecylcarbamoylbenzene "I n Calcium carbonate 5// Silicon oxide III Polyvinyl alcohol l n Water 88n (Liquid No. 5) Naphthol^S 2-part octadecylcarbamoylbenzene 21I calcium carbonate Fall Silicon oxide 1 u styrene/acrylic emulsion 1.5 u water 88
．． 5// [No. 6 liquid] Naphthol AS 2n N-octadecylcarbamoylbenzene calcium carbonate 5 n Polyvinyl alcohol 1 part Styrene/butadiene/acrylic copolymer emulsion 2n Water 8 (in [NoV liquid] Naphthol AS 1.5 parts N- Octadecylcarbamoylbenzene Tripartite silicon oxide 671 Methyl cellulose 0.51! Polyvinyl acetate emulsion 'ln water 85.5# The above composition was dispersed for 24 hours using a ball mill to prepare coupler single-layer dispersions No. 4 to No. 7.

23- [Protective layer liquid] Polystyrene resin (softening point 1.50°C) 15 parts Zinc stearate 2u Silicon oxide 1! ! Cyclohexane 82! The silk composition described above was dispersed in a ball mill for 24 hours to prepare a protective layer dispersion.

[Adhesive layer liquid]

Unsaturated polyester 15 Silicon oxide 5 n Toluene/methyl ethyl ketone (mixing ratio 8/2) 2 Qu The above composition was dispersed in a ball mill for 24 hours to prepare an adhesive layer dispersion.

Next, the adhesive layer dispersion liquid, diazo layer dispersion liquid,
A coupler single-layer dispersion and a protective layer dispersion were applied and dried in that order to obtain a heat-sensitive recording material. In this case, the thickness of the adhesive layer is 5 to 10 μm, and the coating amount of the diazo layer dispersion and the coupler single layer dispersion is 1 to 5 g/rr? (Dry solid content conversion)
The thickness of the protective layer was 3 to 5 μm. Moreover, a polyester film with a thickness of 188 μm was used as the support.

The recording material obtained as described below was printed in GTI mode using a Rifax 303 (manufactured by Ricoh) and then completely exposed and fixed using a Rippy High Start type 4 (manufactured by Ricoh). These things do not develop color even when heated,
The image did not disappear due to organic solvent.

Next, the diazo heat-sensitive material obtained above was subjected to a color density test and a head matching property test.

Furthermore, the film was washed with water for 45 minutes using a washing machine (Uzushio manufactured by National), and the removability of the image area and non-image area was examined. The results are shown in Table-1. In addition, color density gauge fax 3
The solid print density in the G-IT mode of No. 03 was measured using a Macbeth densitometer RD-514. Head matching properties were also determined by examining the occurrence of sticking during solid printing, head staining, and tailing using the G-4 mode of the Rifax 303.

Table 1 From the results shown in Table 1, it is clear that the present invention maintains thermal response and head matching properties without reducing color density, and has excellent washing resistance. .

Patent Applicant Ricoh Co., Ltd. - Representative Patent Attorney Toshiaki Ikeura Proceedings Amendment Document March 1, 1980 Patent Application No. 8109 2, Title of Invention Diazo-based Thermosensitive Recording Material 3, Person making the amendment Relationship to the incident Patent applicant address: 1-3-6 Nakamagome, Ota-ku, Tokyo Name (
674) Rico Co., Ltd. - Representative Hama 1) Hiro 4, Agent 〒151 Address 1-58-10-5 Yoyogi, Shibuya-ku, Tokyo Date of amendment order Voluntary 6 Number of inventions increased by amendment 0 7. Contents of the amendment Column 27-8, Detailed explanation of the invention in the description 8. Contents of the amendment The following amendments will be made in the specification.

(1) Insert "r (No. 1 liquid)" between the 4th and 5th lines of page 21.

(2) Insert "Polyvinyl acetate emulsion 1 part by weight" between page 21, line 10 and line 11.

(3) Correct rl, 12J at the bottom of Table 1 on page 27 (solid print density column of Comparative Example 4) to rl, 02J.

Claims (1)

[Claims] (1) A diazo system in which a plastic is used as a support, a diazo layer containing a diazo compound as a main component and a coupler layer as a main component are laminated on the support, and a protective layer of a water-insoluble resin is provided on the top layer. A diazo-based heat-sensitive recording material characterized in that a water-soluble resin and a water-insoluble resin are used together as a binder in the coupler layer, and calcium carbonate and silicon oxide are contained in the coupler layer as fillers.