JPS58136487A - Diazo base heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To obtain a diazo base heat-sensitive recording material favorable in gate path matching property and excellent in long-period preservability, by a method wherein a protective layer comprising chlorinated rubber particulates is provided on a heat-sensitive color producing layer comprising a diazo compound, a coupler and the like. CONSTITUTION:The protective layer comprising particulates of a chlorinated rubber such as (C5H7Cl3)n, (C5H6Cl4)n or (C10H11Cl7)n with an average particle size of 0.01-10mum is provided on the heat-sensitive color producing layer comprised of a well-known diazo compound, a coupler such as phenol or resorcinol, a thermoplastic material such as an alcohol derivative or a wax, a binder and other auxiliary components. The solvent used in a coating liquid for forming the protective layer must be a nonpolar solvent, such as n-hexane, in which either one or both of the diazo component and the coupling component in the color producing layer are insoluble, and in which the chlorinated rubber is insoluble. A hydrophobic resin such as polystyrene is incorporated into the coating liquid as a binding resin.

Description

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

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. I'm here. 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 the above environment, the entire surface becomes colored and the problem arises that the 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-sensitive 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.

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. In particular, in the field of ticket paper such as commuter passes and train tickets, heat-sensitive recording materials that can print at high speeds and can be fixed are required in order to save labor and reduce expenses associated with fare revisions. . Diazo-based heat-sensitive recording materials have the advantage of being fixable, but when applied to such applications, conventional materials have insufficient matching properties to thermal heads or gate path matching properties for commuter pass applications. It has some drawbacks.

The present inventors have discovered that, unlike conventionally proposed diazo-based thermosensitive recording materials, it has good head-matching properties with respect to thermal heads (no sticking or head scraping), and is free from stains and peeling caused by gate passes at automatic ticket gates. As a result of intensive research to develop a diazo-based heat-sensitive recording material that has excellent long-term storage stability, the present invention has been completed.

That is, according to the present invention, in a heat-sensitive recording material in which a heat-sensitive color forming layer containing a diazo compound, a coupler, a thermofusible substance, and a binder is provided on a support, chlorinated rubber fine particles are provided on the heat-sensitive color forming layer. Provided is a diazo-based heat-sensitive recording material characterized in that it is provided with a protective coating containing the above-mentioned.

The present invention is particularly aimed at improving head matching properties and staining and peeling caused by gate passes when diazo thermosensitive recording materials are used for commuter passes.

When a thermofusible substance is contained in order to satisfy thermal responsiveness, staking, image blurring, footing, etc. are likely to occur, and the surface is likely to be stained and peeled off when gate-passed. It has been found that providing a protective coating containing fine chlorinated rubber particles having an average particle size of 0.01 to 10 .mu.m on the thermosensitive coloring layer is effective in improving head matching and surface durability.

Chlorinated rubber in the present invention is defined as chlorinated synthetic rubber or natural rubber, and is manufactured by chlorinating using a chlorinating agent such as chlorine gas or H (J gas). , formula % formula %) etc. (molecular weight: usually aoo.

~200000) are included. The chlorine content in chlorinated rubber is usually at least 65% by weight, and its thermal decomposition temperature is usually at least 250°C.

The solvent of the coating liquid for forming the protective layer used in the present invention must be a non-polar solvent that does not dissolve either the diazo component or the coupling component, or both, contained in the lower heat-sensitive coloring layer, and that does not dissolve the chlorinated rubber. It's okay. Further, as the resin for binding the guardian, it is desirable to use a hydrophobic resin that dissolves in a non-polar solvent.

When preparing a coating solution for forming a protective film layer, examples of non-polar solvents such as n-hexane and cyclohexane are used, and examples of hydrophobic resins include polystyrene, polyester, vinyl chloride, and styrene-toluene vinyl copolymer. The average particle size of the chlorinated rubber is 0.01 to 1.
It is preferable to use one in the range of 0μ, preferably in the range of 0.05 to 3μ.

In order to make the average particle size of the chlorinated rubber '6o, oi ~ 10μ, a generally known ball mill, attritor,
Particles can be adjusted using a device such as a sand mill.

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

The diazo compound and coupler used in the present invention are those commonly used in diazo photosensitive paper, and include, for example, those shown below.

Diazo Compound: As the diazo compound used in the present invention, a commonly used diazo compound, for example, one represented by the following general formula is used.

R9 However, in general formulas (+), (II) and [flat], R
45Ra r Rs is hydrogen, nor is hydrogen, the C1 to C6 alkyl group is also a lucoxyl group, R4+R5 is the same or different 01 to C3 alkyl group, hydroxyalkyl group,
or elementary, halogen, trifluoromethyl group, C1-C3
(R14t Rti + Rta: same as Rta), M I + M 2νM, is an acid residue or an acid residue forming a double salt with a metal salt.

In this case, the acid residues include halogen ions, B P, -
.

Fluorine-containing inorganic acid ions such as PF and -'' are preferable, while metal salts that form double salts with acid residues include, for example, 'ZnO12+ 0dO12t 5nO
There are 12 etc. Y represents 10H2- or -00-, and is nFio or 1.

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

Specific examples of those corresponding to (JLIHs general formula C11) include the following.

As specific examples of what corresponds to the general formula (Ifi), the following can be mentioned.

In the present invention, in order to obtain a product with further improved long-term shelf life, -BP is used as the diazo compound.

Advantageously, they are used in the form of water-insoluble salts such as fluorine-containing salts such as -PF6 and -PF6.

Katupura m: Couplers used in the present invention include phenol, resorcin, methylresorcin, 494-bisresorcin,
Phloroglucin, resorcinic acid, phloroglucinic acid, 2
-Methyl-5-methoxy-193-dihydroxybenzene, 5-methoxy-1+3-dihydroxybenzene, 4
-N9N-dimethylphenol, 2t6-dimethyl-1
+3t5-trihydroxybenzene, 296')
Hydroxy ben, number, 296-hydroxy-325
- Phenol derivatives such as dibromo-4-methoxybenzoic acid, α-naphthol, β-naphthol, 4-medoxy-1-naphthol, 223-hydroxynaphthalene, 2
Naphthols such as T3-dihydroxynaphthalene-6-sulfonic acid soda, 2-hydroxy-3-propylmorpho1), nonaphthoic acid, 2-hydroxybenzo-3-naphtho-0-toluicide, 2-hydroxy-3-naphthoic acid morpholinopropylamide, etc. Examples include derivatives, but of course the invention is not limited to these.1. Any substance that can act as a coupler for the diazo compound can be applied.

Thermofusible substances: Examples of thermofusible substances include the following.

2-)! Alcohol derivatives such as J-bromoethanol, 2t2 & methyltrimethylene glycol, 192-cyclohexanediol, acid derivatives such as malonic acid, glutaric acid, maleic acid, methylmaleic acid, animal waxes such as beeswax and shellac wax, carnauba wax etc. Vegetable waxes, mineral waxes such as montan wax, petroleum waxes such as paraffin wax, microcrystalline wax, and other synthetic waxes such as polyhydric alcohol esters of higher fatty acids, higher amines, higher amides, and fatty acids. Condensates with amines, condensates with aromatics and amines, synthetic paraffins, chlorinated paraffins, metal salts of higher fatty acids,
Higher linear glycols, 3+4-epoxydialkyl hexahydrophthalate, 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, based on the diazo compound type 1 container.
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 heat-sensitive coloring layer on the support, and examples of such binders include those shown below.

Polyvinyl acetate 1. Polyvinyl chloride, vinyl chloride/vinyl acetate copolymer, polyacrylic acid ester, polystyrene, polybutadiene, polyacrylamide, styrene/
Butadiene, acrylic copolymers, petroleum resins, 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 modified resin, iso(or diyne)butylene-maleic anhydride copolymer, phenol Water-soluble, organic solvent-soluble, or water-based dispersion resins such as resins and melamine resins.

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

Further, in the present invention, the heat-sensitive coloring layer may further contain acidic substances, basic substances, fillers, and other substances as auxiliary components, if necessary.

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

Tartar, 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.

Filler: A filler is added to improve the matching property to a thermal head when heating is performed by a thermal head, and examples of such fillers include the following.

Organic and inorganic solid particles such as styrene resin particles, urea-formalin condensate resin particles, aluminum hydroxide, magnesium hydroxide, calcium carbonate, titanium, talc, kaolin, silica, and alumina.

As other auxiliary ingredients, zinc chloride, zinc sulfate, sodium citrate, guanidine sulfate, calcium gluconate, sorbitol, sucrose, 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 each of the coating solutions is coated on a support and dried. Product. In this case, 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. Such solvents include water or an aqueous medium in which an organic solvent is dissolved in water, benzene, toluene, xylene, n-hexane, n-hebutane, cyclohexane, kerosene, methyl isobutyl ketone, methyl cellosolve, acetone, methyl ethyl ketone, Examples include nonpolar or polar organic solvents such as dimethyl ether and siloxane.

Next, the protective film of the present invention is applied to a thickness of 1 to 10 μm on the heat-sensitive coloring layer formed as described above, and dried to obtain a product.

The heat-sensitive recording material of the present invention can be advantageously applied in various fields of heat-sensitive recording, particularly as ticket paper for commuter passes and train tickets that require high-speed recording. Characters and images recorded on the surface can be fixed by forming the image by heating and then decomposing the unreacted diazo compound with light. Further, the heat-sensitive recording material of the present invention can be used to record securities, gift certificates, etc. by utilizing its fixing properties.
Recording of necessary information for admission tickets, certificates, slips, etc.
It can be applied to their creation.

Next, the present invention will be explained in more detail with reference to Examples.

Example A liquid: QC! ,H.

Stearic acid amide 15/
/n-hexane 73
〃The above composition was dispersed for 24 hours using a ball mill,
Dispersion A was prepared.

Solution B: Phloroglycin 5 parts by weight N-octadecyl (4-methoxycarbonyl) 10J
i parts - benzamide calcium carbonate 1
Sodium thiosulfate 1
〃Polyvinyl alcohol (10% aqueous solution) 2
0 tt water
63〃The above composition was mixed with 2 using a ball mill.
Dispersion B was prepared by dispersing for 4 hours.

Liquid C Nialologlycine 5 parts by weight N-octadecylcarbamoylbenzene 1
0 Silica 2 Toluene 8 o The above composition was dispersed for 24 hours using a ball mill to prepare Dispersion C.

D liquid 002H.

Stearic acid amide 5 parts by weight Cyclohexane 90
The above composition was dispersed for 24 hours using a ball mill to prepare a dispersion liquid DI.

F liquid: Polystyrene resin (softening point: 150℃) 10
Part by weight calcium carbonate
5 〃Cyclohexane
85. Dispersion E was prepared by dispersing the above composition for 5 hours using a ball mill.

F liquid: Polystyrene (softening point: 150°C) 1
0 parts by weight cyclohexane
85〃The above composition was dispersed for 5 hours using a ball mill to prepare Solution F.

A diazo thermosensitive recording material was prepared by coating the dispersion and solutions A to F prepared as described above on a support using the combinations shown in Table 1 and drying them. The amount of adhesion of the can liquid is 1.
0-a, or/m2 (solid content), and the thickness of the resin coating was 3-5μ.

The recording material obtained as described above was printed using a Rifax 303 (manufactured by Ricoh Co., Ltd.) in G-11 mode, and then completely exposed using a Ricopino Istart type 4 (manufactured by Ricoh Co., Ltd.). and established it. These materials did not develop color even when heated, and the images did not disappear when exposed to organic solvents.

Next, the diazo thermosensitive recording material obtained above was subjected to a color density test and a storage stability test. The results are shown in Table-2. In addition, the color density is 1 no fax 303 Q-n
Macbeth Density Meter RD-514
It was measured with In order to test the head matching performance of 2t, the occurrence of sticking during solid printing in the G-n mode of the Refax 303 was investigated. In addition, gate inspections at automatic ticket gates were conducted 100 times. The results are shown in Table 2.

From the results shown in Margin Table 2 below, it can be seen that all the products of the present invention have satisfactory quality.

Patent applicant Ricoh Co., Ltd. Agent: Patent Attorney Toshiaki Ikeura

Claims (1)

[Claims] (1) In a heat-sensitive recording material in which a heat-sensitive coloring layer containing a diazo compound, a coupler, a thermofusible substance, and a binder is provided on a support, a protective coating containing chloride rubber fine particles is provided on the heat-sensitive coloring layer. A diazo-based heat-sensitive recording material characterized by: