JPS59104994A - Diazo base heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To provide a diazo base heat-sensitive recording material such that a developed color image is prevented from being transferred to a pass case or the like, wherein a heat-sensitive color forming layer comprising a diazo compound and a coupler and a specified overcoat layer are sequentially provided on a base. CONSTITUTION:The heat-sensitive color forming layer comprising a diazo compound (e.g., a compound of the formula) and a coupler (e.g., phenol), preferably with a heat-fusible substance (e.g., malonic acid) and, if required, an acidic substance (e.g., tartaric acid), a filler (e.g., silica) and the like is provided on the base (e.g., paper). Further, the overcoat layer of a polymer having an SP value (solubility parameter) of not lower than 10 (e.g., polyethylene terephthalate) is provided on the color forming layer in a thickness of ordinarily about 0.1- 30mum to obtain the objective diazo base heat-sensitive recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical breakdown] The present invention relates to a heat-sensitive recording material, particularly a heat-sensitive recording material that can be photofixed. That is, the present invention relates to a diazo-based thermosensitive recording material that develops color when recorded with a thermal head at a certain temperature, loses its ability to develop color in non-printed areas when further irradiated with light, and does not recolor when heat is applied again. It is.

[Prior art]

In addition to being used as copy paper for books and documents, thermosensitive recording materials are also used as output recording paper for computers, facsimile machines, medical measuring machines, etc., as well as thermal recording magnetic ticket paper and thermal recording label paper. be done. However, it is still possible to use heat-sensitive recording materials as paper for creating securities, gift certificates, admission tickets, certificates, slips, etc. by taking advantage of the ease of automatic recording. For applications, heat-sensitive recording materials must be fixable in order to obtain high recording reliability.

As such fixable heat-sensitive recording materials, various diazo-based heat-sensitive recording materials have been proposed that utilize a color-forming reaction between a diazo compound and a coupler.

However, when such diazo-based heat-sensitive recording materials are used as commuter passes, etc., they are usually made of soft polyvinyl chloride.
In many cases, it is stored in the ξ case, but in such cases, the colored image part of the commuter pass that is in contact with the ξ case is
There is a problem of transcriptional transfer to the ξ scale. Unfortunately, the )ξ case becomes dirty, making it difficult to use, or the commuter pass is likely to be tampered with using the colored image transferred to the ξ case.

〔the purpose〕

The present invention was completed as a result of various researches aimed at solving the problems of the transferability of colored images to the surface of the .xi.

〔composition〕

That is, according to the present invention, in a case where a heat-sensitive coloring layer containing a diazo compound and a cassillar is provided on a support, an sp value (dissolution/ξ rameter) of 10 is provided on the heat-sensitive coloring layer.
A diazo thermosensitive recording material is provided, which is characterized by being provided with a polymer overcoat layer having the above properties.

The present invention is characterized in that a polymer overcoat layer having an sp value of 10 or more is provided on the thermosensitive coloring layer.
The sp value in this case indicates the dissolution/ξ parameter of the polymer and is expressed by the following formula.

5P=(B/V)3″ E...Cohesive energy density of polymer (cab/mob
)■...Molar volume of polymer (α3/mob) The details are described, for example, in the Kagakubin column, Applications edition (Nippon Kagaku Kinwa). According to the research conducted by the present inventors, it was confirmed that when such a polymer overcoat layer with an sp value of 10 or more is provided, transfer of the colored image to the ξ scale surface is effectively prevented. Santa. sp value is l
The use of polymers smaller than O makes it difficult to effectively prevent the transfer of colored images.

Examples of polymers having an sp value of 10 or more used in the present invention include polyethylene terephthalate, cellulose diacetate, epoxy resin, polyvinylidene chloride, 6,6-nylon, polyacrylonitrile, polyvinyl alcohol, and the like. The thickness of the overcoat layer is usually 0.1 to 3
It is about 0 μm. Additionally, auxiliary components such as fillers can be added to this overcoat layer.

1. Used in the present invention. As the diazo compound and coupler, those commonly used for diazo photosensitive paper are applicable, and examples thereof include 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.

I 9 However, in general formula [1], (I+) and [■],
RI +"6+几8 is hydrogen, halogen, R9 is hydrogen, halogen, cl-05 is an alkyl group or alkoxyl group, "41R5 is the same or different C, -C5 alkyl group, hydroxyalkyl group, or alkoxyl group, parent is halo'I)
, R7 is hydrogen, halogen, trifluoromethyl group, 01
~C5 alkyl group or alkoxyl group, or (R
141R15+ R16' Same as R13), M, ,
M2. M3 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 and BF4-1
Fluorine-containing inorganic acid ions such as PF6- are preferable, while metal salts that form double salts with acid residues include, for example, ZnCj'2. cdCJ'2, 5nC1
There are 2 etc.

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

0C2H5 Specific examples of those corresponding to the general formula [■] include the following.

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

0021 (5 CH3 In the present invention, in order to obtain a product with even higher long-term shelf life, as a diazo compound, ■lBF4 and HJ'F
Advantageously, it is used in the form of a water-insoluble salt such as a fluorine-containing salt such as 6.

Cassilla used in the present invention includes phenol, resorcin, methylresorcin, 4,4-bisresorcin,
Phloroglucin, resorhetonic acid, phloroglucic acid, 2
-Methyl-5-methoxy/-X, a-, ,; Hydroxypenzene, 5-methquine-1,3-dihydroxybenzene, 4-N,N-dimethylphenol, 2,6-dimethyl-1.3. 5-trihydroxybenzene, 2.6-)
Hydroxybenzoic acid, 2,6-cyhydroxy-3,5-
Schiff + phenol derivatives such as lomo-4-methoxybenzoic acid, α-naphthol, β-naphthol, 4-methoxy-1-naphthol, 2,3-dihydroxynaphthalene, sodium 2,3-dihydroxynaphthalene-6-sulfonate, 2-hydroxy-3-propylmorpholinonaphthoic acid, 2-hydroxy-3-naphtho-0-toluicide,
2-hydroxy/-3-naphthoic acid morpholinopropylamide, naphthol derivatives such as naphthol derivatives, acetoacetanilide, 4-benzoylamino-2,5-diethoxy/acetoacetanilide, N-acetoacetooctadenylamine, N, N'- Examples include active methylene compounds such as bis(acetoaceto)decane-1,10-diamine and 2,4.6-tribromoacetoacetanilide, but are not limited to these, and diazo Any compound that can act as a C coupler can be applied.

In the present invention, thermofusible substances are preferably used in order to enhance rapid color development. Specific examples of such things include, for example, the following:

Alcohol derivatives such as 2-tribromoethanol, 2,2-dimethyltrimethylene glycol, l,2-cyclohexanediol, acid derivatives such as malonic acid, curtaric acid, maleic acid, methylmaleic acid, and animals such as beeswax and shellac wax. waxes, vegetable waxes such as carnauba wax, mineral waxes such as montan wax,
/8 Petroleum waxes such as rough-in 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 aromatic acids and amines , synthesis/
ξ rough-in, chloride/ξ rough-in, metal salts of higher fatty acids,
Higher linear glycols, dialkyl 3,4-ebo/hexahydrophthalate, 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 the acid content 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 it in a proportion of 5 parts by weight or more for high-speed output recording devices such as facsimile machines. 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, the heat-sensitive coloring layer may further contain -C1 acidic substances, basic substances, fillers, and other substances as auxiliary components, if necessary.

Acidic substances: Acidic substances are added as necessary to prevent coupling reactions and improve storage stability. Examples of the acidic substances include the following.

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

Filler: A filler is added to improve the matching property with the thermal spatula 1 when heated by the thermal spatula 1, and examples of such filler 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, lyca, and alumina.

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 the present invention, a binder is applied in order to firmly support the heat-sensitive coloring layer on the support. In this case, the binder may be a conventional binder, such as polyester, polystyrene, chlorinated rubber, or polyester. Vinyl chloride, polyvinyl chloride, polycitadiene, polyacrylic ester, vinyl chloride/vinyl acetate copolymer, polycitadiene, styrene/citadiene/acrylic copolymer, polyethylene, ethylene/vinyl acetate copolymer, styrene/acrylic copolymer , polyvinylidene chloride, vinylidene chloride/acrylic copolymer,
In addition to organic solvent-soluble or water-dispersible resins such as phenolic resin, urea/formalin resin, and melamine resin, polyvinyl alcohol, polyacrylamide, casein, gelatin, starch and its derivatives, polyvinylpyrrolidone, calhoki/methylcellulose, methylcellulose, ethylcellulose, Water-soluble resins such as styrene-maleic anhydride copolymer and iso(or diiso)zotylene-maleic anhydride copolymer can also be used. In particular, in the present invention,
To more effectively prevent the transfer of colored images,
As this binder, it is effective to use a polymer having the aforementioned S'P value of 10 or more.

The supports used in the present invention include paper, synthetic paper, plastic film, and paste prepared by precoating paper with synthetic resin, filler, etc.

〔effect〕

Since the diazo-based heat-sensitive recording material of the present invention has a special overcoat layer formed on the heat-sensitive color layer, there is the problem of transfer of colored images to other solid surfaces, which was seen in conventional materials. There isn't.

〔Example〕

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

Reference Example Solution A: C2H5 Methyl Celsorzo 67,/B
Liquid/liquid: Full As 3 parts by weight Sodium benzoate 15
Part by weight Silica 2 〃10% Methyl cellulose water soluble i 20 // Water
58 〃
Liquid C: Calcium acid 2 parts by weight Unsaturated polyester resin (sp value 10.7) to //
water 88
,.

Liquid B: Same as liquid C except that the unsaturated polyester resin was changed to 20 parts by weight.

Solution E: Same procedure except that the unsaturated polyester resin in Solution C was changed to a polyvinylidene chloride resin (sp value 12.2). Solution E: Same as the solution except that the polyvinylidene chloride resin in Solution E was changed to 20 parts by weight.

Disperse composition B-F in a ball mill for 24 hours and -C
Each dispersion liquid B-F was prepared. In addition, Solution A was prepared by stirring and dissolving for 1 hour.

Example 1 Liquid A was applied to the surface of a plastic sheet (200!i'/m2) and dried to form a first layer with a coating amount of 217 m2, and liquid B was applied on top of this and after drying, the coating amount was 77 m2. A second layer was formed, and liquid C was further applied and dried on the second layer to form a third layer having an adhesion amount of o and 2y/m2 to obtain a heat-sensitive recording sheet.

Examples 2 and 3.4 A thermosensitive recording sheet was obtained in the same manner except that liquid C in Example 1 was replaced with B and F@, respectively.

Comparative Example C liquid: Calcium carbonate 2 parts by weight Polystyrene resin (SP value 8.6) IQ tt water 88
〃Hi: Same except that the polystyrene resin of liquid C was increased to 20% by weight.

■Liquid: Polyethylene resin is used instead of polystyrene resin 9 in Liquid C.

J liquid: ■Increase the amount of polyethylene resin in the liquid to 20% by weight.

Comparative thermosensitive plates were obtained in the same manner as in Example 1, except that the above-mentioned Liquids C to Jo were applied instead of Liquid C in Example 1.

Each diazo thermosensitive recording sheet obtained in the above manner,
Gl using Rifax 303 [manufactured by Ricoh Co., Ltd.]
After printing with l mode 1, recopy high start 205
[Manufactured by Ricoh Co., Ltd.] was used to completely expose and fix the images, and after storing these images for 3 months in a soft polyvinyl chloride case, the transfer of the image area was observed. It was confirmed that the overcoated product had no transfer transfer compared to the comparative example, and was of high quality.

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

Claims (1)

[Claims] (1) A thermosensitive coloring layer containing a diazo compound and a coupler is provided on a support, and the SP value (dissolution) ξ rameter) on the thermosensitive coloring layer is i. A diazo-based heat-sensitive recording material characterized by being provided with a polymer O/ζ coating layer having the above properties.