JPH02172786A - Heat sensitive recording material - Google Patents

Abstract

PURPOSE:To enhance sensitivity and to eliminate fog of a skin by providing a heat sensitive recording layer containing leuco dye, developer and porous calcium carbonate having specific oil absorption value on a support to form a heat sensitive recording material. CONSTITUTION:Leuco dye, developer and polyvalent calcium carbonate having 120ml/100g or more of oil absorption amount in Ogura method boiled linseed oil (JIS K=5101.19) are dispersed in a binder such as polyvinyl alcohol, etc., to prepare a heat sensitive recording layer forming coating solution. A support such as paper, plastic film, etc., is coated with the coating solution, and dried to form a heat sensitive recording layer, thereby obtaining a heat sensitive recording material. The leuco dye desirably includes, for example, compound represented by a formula I (where R1, R2 are 1-6C alkyl group, cycloalkyl group). A concrete example of the developer includes, for example, bentonite, zinc oxide, salicylic acid, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to improvements in heat-sensitive recording materials containing leuco dyes as color formers.

[Prior art] Thermosensitive recording materials generally have a thermosensitive coloring layer mainly composed of a hot valve e+ biocomposition on a support such as paper, synthetic paper, or plastic film. A colored image can be obtained by heating with, etc. Compared to other recording materials, this type of recording material does not require complicated processing such as development and fixing, can produce records in a short time using relatively simple equipment, and generates less noise and pollutes the environment. Due to its advantages such as low cost, it is used not only for copying illustrated books and documents, but also as a recording material for various purposes such as electronic sieving machines, facsimile machines, ticket vending machines, labels, and recorders. Thermochromic compositions used in such heat-sensitive recording materials generally consist of a color former and a color developer that thermally develops the color. As the color former, for example, a colorless composition having a lactone, lactam or spiropyran ring is used. Alternatively, light-colored leuco dyes are used, and various acidic substances such as organic acids and phenolic substances are used as color developers. Recording materials made by combining this color forming agent and color developing agent have particularly clear image tones, high whiteness of the background, and weather resistance of the image (dye image). It has advantages and is widely used.

In recent years, as heat-sensitive recording materials have replaced other conventional recording methods and their demand has increased, there has been an increasing demand for improved quality of the heat-sensitive recording materials used in this heat-sensitive recording method, and there is a need for faster speeds and higher sensitivity. At the same time, there is a need for a heat-sensitive recording material that has excellent head matching properties and does not cause troubles such as adhesion of residue to the head and does not affect the life of the head.

One way to achieve this high sensitivity and head matching performance is to use silica as an additive in the heat-sensitive coloring layer, but if the amount used increases, the density of the printed image will decrease, and the gear rendering process will cause the background to deteriorate. It has the disadvantage that it may cause fogging on the parts.

In addition, Ogura-boiled linseed oil (JIS K-5101/19), which has been conventionally used as an additive for heat-sensitive coloring layers, has a rating of 90rd! With calcium carbonate of about 100 q, it is not possible to obtain sufficient stone feel and density, and there is also a drawback that there is a large amount of residue attached to the head, so no satisfactory result has been obtained by any of the methods. This is the current situation.

[Problem to be solved by the invention 1] The present invention has high sensitivity, high density, no fogging on the background,
The problem to be solved is to provide a heat-sensitive recording material that also has good head matching properties.

[Means for Solving the Problems] According to the present invention, in a heat-sensitive recording material utilizing a color reaction between a leuco dye and a color developer,
According to JIS K-5101/19), 120 M
A heat-sensitive recording material characterized by containing porous back-type calcium carbonate having an oil absorption amount of L/100 fJ or more is provided.

As the leuco dye, compounds represented by the following formula (i>) are preferred.

(In the formula, R1 and R2 represent a C1 to C6 alkyl group or a cycloalkyl group.) More preferred is the general formula (I> in which R1 and R2 are C1 to C6 alkyl groups or cycloalkyl groups)
It is a compound that is a C4 alkyl group.

In the present invention, linseed oil (JIS K~5101)
・In 19), porous back-type calcium carbonate with an oil absorption of 120〃I2/100g enhances the pigment effect with a smaller amount than calcium carbonate with an oil absorption of less than 120, so it is more likely to occur with calcium carbonate with an oil absorption of less than 120. An excellent heat-sensitive recording material is provided in which the density of the heat-sensitive paper is less likely to decrease due to an increase in the blending amount.

In the present invention, the 7-man song (JISK-51
In 01/19), a porous cross-type carbonate with an oil absorption of 120 m/tOog or more was used, and lucium was mixed with leuco dye 1.
By using it in the range of 0.5 to 15.0 Iffi parts for the heavy parts, a heat-sensitive recording material with high sensitivity and high density, no background fogging, and excellent head matching properties can be obtained. In addition, the linseed oil used in the present invention (JIS K
-5101.19>, porous back type calcium carbonate having an oil absorption of 120 I/100 q or more may be used in combination with two or more types of additives depending on the case. Furthermore,
This Ogura-boiled linseed oil (JISK-5101-19:
), porous back-type calcium carbonate having an oil absorption of 120n+j/100g or more may be provided as an undercoat layer on the support alone or in combination with other auxiliaries. Further, depending on the case, it may be provided as an overcoat layer on the heat-sensitive coloring layer alone or in combination with other auxiliary agents.

The leuco dyes used in the present invention may be applied singly or in a mixture of two or more types, and as such leuco dyes, those applied to this type of heat-sensitive recording material may be arbitrarily applied, such as , triphenylmethane group, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, and indolinophthalide-based dye compounds are preferably used. Specific examples of such leuco dyes include those shown below.

33-bis(p-dimethylaminophenyl)-phthalide, 3.3-bis(p-dimethylaminophenyl)-〇-dimethylaminophthalide (also known as Crystal Violen 1 Heractone), 3.3-bis(p-dimethylamino phenyl)-〇diethylaminophthalide, 3.3-bis(dimethylaminophenyl)-6-chlorphthalide, 3.3-his(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlor Fluorane, 3
- Dimedyl 7 minnow 5,7-dimethylfluorane, 3-
(N,N-diethylamino)-5-methyl-7-(N,
N-dibenzylamino) fluorane, penzoylleucomedylene blue 6°-chloro-8°-methoxy-benzoindolino-pyrillospirane, 6-bromo-3゛-mel-xy-benzoindolino-pyrillospirane, 3 -(2°-hydroxy-4-dimethylaminophenyl)-3-(2°-methoxy-5'-chlornoenyl)phthalide, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2- Me1~xy5゛-nitrophenyl)
Phthalide, 3-(2'-hydroxy-4-diethylaminophenyl)-3-(2'-methoxy-5"-methylphenyl)phthalide, 3-(2'-methoxy-4'-dimethylaminophenyl)-3- (2'-and droxy-4'-chloro-5'-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trinoromethylanilino Linofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)nororane, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino- 5-chloro-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylph fluoran, 3-diethylamino-5-methyl-γ-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-n
-Butylanilino>Fluorane, 3-(N-methyl-N-isopropylamino)-6-methyl-7-anijnofluorane, 3-dibdelamino-6-methyl-7-7nilinofluorane, 3.6-his(dimethylamino) Fluorene Spiro (9)
,3')-6'-dimethylaminophthalide, 3-(N-
benzyl-N-cyclohexylamino)5.6-penzo7-α-naphthylamino-4-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N-(2 -ethoxypropyl)amino-6-methyl-7-anilinofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3 -diethylamino-
6-Methyl-7-chlorofluorane 3-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-anilinofluorane, 21N- (3°-trifluoromethylphenyl)amine)-6-dinithylaminofluorane, 2- (3,6-
3-diethylamino-6-methyl-7-(m-trichloromethylanilino)
Fluoran, 3-diethylamino-7-(o-chloraniυ))fluorane, 3-dibutylamino-7-rihochloroanilino)nororane, 3-tomethyl-doamylamino-6-methyl-7-anilinofluorane, 3-N -Methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-te1-rahydrofurfurylamino 6-Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-fumesitidino 4',5'-benzofluorane, 3-N-methyl-N-isobutyl-6-methyl-7-ani Linofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-(2',4'-
dimethylanilino) fluorane, etc.

In addition, as the color developer used in the present invention, various electron-accepting substances that develop color with respect to the above-mentioned Roy dye are used, and specific examples thereof include phenolic substances, organic Alternatively, inorganic acidic substances v1 or their esters and salts can be mentioned.

bentonai 1~, zeolite 1~, acid clay, activated clay,
Silica gel, zinc oxide, zinc chloride, zinc bromide, aluminum chloride, salicylic acid, 3-tert-butyl]isocylic acid, 3.5-di-tert-butylsalicylic acid, m-chlorophenylthiourea, trifluoromethyl Phenylthiourea, di-phenylthiourea, salicylanilide, 4.4-isopropylidenediphenol, 4,
4'-isopropylidene bis(2-chlorophenol)
, 4.4'-isopropylidene bis(2,6-dibrophenol), 4.

4°-isopropylidene bis(2,6-dichlorophenol), 4,4°-isopropylidene bis(2-methylphenol), 4,4′-isopropylidene his(
2,6-dimethylphenol), 4,4'-isoprolidene bis(2-tert-butylphenol, 4.4
- sec-butylidene diphenol, 4,4-cyclohexylidene hisphenol, 4,4°-cyclohexylidene bis(2-methylphenol), 4-tert-
Butylphenol, 4-phenylphenol, 4-bitroxydiphenoxide, α-naphthol, β-naphthol, dimethyl 5-hydroxyphthalate, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone, Noholak-type phenolic resin, 2,2" -Thiohis (4
, 6-dichlorophenol), catechol, resorcinol, hydroquinone, pyrogallol, phloroglycine, phloroglycincarphonic acid, 4-tert-octyl cathol, 22'-methylenebis(4-chlorophenol), 2,2'-methylenebis (4-methyl-6-te
rt-petimephenol), '2,2-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-p-hydroxybenzoate Chlorbenzyl, p-hydroxybenzyl Q-
0-Chlorbenzyl, p-hydroxybenzoic M-p-methylbenzyl, p-hydroxybenzoic 1-n-octyl, benzoic acid, curved salicylate, 1-hydroxy-2-naphthoic acid, 2-hydroxy-6-naphthoic acid acid, zinc 2-hydroxy-6-naphthoate, 4-hydroxydiphenylsulfone, 4,2°-diphenolsulfone, 4-hydroxy-4°-chlorodiphenylsulfone, 4-hydroxy-4°-henzyl oxydiphenyl sulfone,
4-hydroxy-4°-isopropoxydiphenylsulfone, 4-hydroxy-4-isobutyloxydiphenylsulfone, bis(4-hydroxyphenyl)sulfide, 2-hydroxy-p-toluic acid, 3,5-sheeter
3,5-tert
-tin butylnaritylate, tartaric acid, oxalic acid, maleic acid, citric acid, cono-phosphoric acid, stearic acid, 4-hyperoxyphthalic acid, boric acid, biimidazole, hexaphenylbiimidazole, carbon tetrabromide, methylene bis(oxy) ethylenethio)diphenol, ethylenebis(oxyethylenethio)diphenol, his(4-hydroxyphenylthioethyl)ketone, bis(4-hydroxyphenylthioethyl)ether, m-xylylenebis(4-
hydroxyphenyldio)ether, etc.

In the present invention, various commonly used binders can be used as appropriate to bind and support the above-described dye and color developer on a support, such as polyvinyl alcohol, polyvinyl alcohol,
Starch and its constituents, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose,
Cellulose derivatives such as methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone,
Acrylamide/acrylic acid ester copolymer, acrylamide/acrylic acid ester/methacrylic acid terpolymer, styrene/maleic anhydride copolymer alkali salt,
In addition to water-soluble polymers such as isobutylene/maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, and polyacrylic acid ester , vinyl chloride/vinyl acetate copolymer, polybutyl methacrylate, ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer latex, etc. can be used.

In addition, in the present invention, in addition to the leuco dye and color developer, if necessary, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants,
A thermofusible substance (or lubricant), etc. can be used in combination.

In this case, Ogura-boiled linseed oil (JIS K-5101/
19), fillers that can be used alone or in combination with porous calcium carbonate having an oil absorption ratio of 120I7112/100g or more include conventionally known general fillers such as ml calcium, silica, zinc oxide, titanium oxide, and hydroxide. aluminum, zinc hydroxide, barium sulfate,
In addition to inorganic fillers such as clay talc and surface-treated calcium silica, urea-formalin resin, styrene-
Examples include organic fillers such as methacrylic acid copolymers and polystyrene resins. Examples of thermofusible substances include higher fatty acids or their esters, amides, or metal salts, various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, Examples include dialkyl 3,4-epoxy-hequinahydrophthalate, higher ketones, and other heat-fusible organic compounds having a melting point of about 50 to 200°C.

The heat-sensitive recording material of the present invention can be produced by applying a heat-sensitive layer-forming coating solution containing the above-mentioned components onto a suitable support such as paper, synthetic paper, or plastic film, and drying it. applied to.

[Effects of the Invention] The heat-sensitive recording material of the present invention has high sensitivity and high temperature, is free from fogging on the background, and has excellent head matching properties.

[Example 1 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.

[△Liquid] 3-dibutylamino-6-methyl-7-anilinofluorane 20 parts 10% polyvinyl alcohol aqueous solution 20 parts water
60 parts [Liquid B 1 4.4'-methylenebis(oxyethylenethio)diphenol t6ars22'-methylenebis(3-methyl-6-t-butylphenol)] 4 parts Zinc stearate
5 parts 10% polyvinyl alcohol aqueous solution 20 parts water
55 parts [Liquid C 1 Ogura-boiled linseed oil (JIS K-5101/19) contains 120 ML/100 (porous calcium carbonate (Callite-KT, Kokura-boiled linseed oil) with an oil absorption of 1 or more). JIS K-5101/19) Oil absorption distance 140m
/100g (manufactured by Shiraishi Kogyo Co., Ltd.) 20 parts 10% polyvinyl alcohol aqueous solution 10 parts water
70 parts Example 1 The above Δ solution and B solution were each dispersed using a Nando mill so that the average particle size was 2 μm or less. Commercially available tsuboka approx. 52g/
1 part of liquid A, 4 parts of liquid B, 4 parts of liquid C, and 10 m high-quality paper.
% Polyvinyl alcohol aqueous solution mixed and stirred to prepare a heat-sensitive coloring layer forming coating solution, after drying, the dry amount was 715% or 60%.
The heat-sensitive recording material of the present invention was prepared by applying and drying the coating to give a smoothness of about 500 seconds using a super gear render.

Example 2 In liquid C of Example 1, small 0 method boiled linseed oil (JIS
K-5101-19), 120m/100
Instead of 20 parts of porous calcium carbonate that has an oil absorption of more than
In 9), Example 2 was prepared in the same manner as in Example 1 except that 10 parts of porous calcium carbonate having an oil absorption of 1 or more and 10 parts of general calcium carbonate were used in combination. A thermosensitive recording material was obtained.

Example 3 In liquid C of Example 1, Ogura method boiled linseed oil (JIS
K-5101-19), 12 (7/100
Ogura-boiled linseed oil (JIS K-5101/
19), 10 parts of porous calcium carbonate with an oil absorption of 120 m/100 g or more and 1 part of general silica.
The heat-sensitive recording + A gain of Example 3 was 1q in the same manner as in Example 1 except that 0 copy was used for burrs.

Example 4 In Example 1, liquid C was applied as an undercoat layer between the commercially available high-quality paper with a basis weight of about 52 q/end and the heat-sensitive coloring layer so that the dry cloth gradient was 4 g/'Irt after drying *2. A heat-sensitive recording material of Example 4 was obtained in the same manner as in Example 1 except that the following materials were used.

Example 5 In the C solution of Example 4, Kojibo boiled linseed oil (JIS
K-5101-19>, 120+m/1
Porous calcium carbonate 20 with oil absorption of 00g or more
In place of the part, use boiled flaxseed oil (JIS K-5101
- In 19), the heat-sensitive recording material of Example 5 was obtained in the same manner as Example 4 except that 10 parts of porous calcium carbonate having an oil absorption of 120 m1/100 g or more and 10 parts of polystyrene were used in combination. .

Comparative Example 1 In liquid C of Example 1, small 0 method boiled linseed oil (JIS
K-5101-19), 120d/1
A heat-sensitive recording material of Comparative Example 1 was obtained in the same manner as in Example 1, except that ordinary silica was used instead of porous calcium carbonate having an oil absorption of 0.00 g or more.

Comparative Example 2 In liquid C of Example 1, Ogura-boiled linseed oil (JIS
K-5101-19>, 120m1/10
Ogura-boiled linseed oil (JIS K-5101/19) instead of porous calcium carbonate with oil absorption of 0q or more
A heat-sensitive recording material of Comparative Example 2 was obtained in the same manner as in Example 1 except that 90 m1/100 (I) calcium carbonate was used.

Comparative Example 3 In liquid C of Example 1, Ogura method boiled linseed oil (JIS
K-5101/19), 120d/10
Ogura-boiled linseed oil (JIS K-5101/
In 19), one batch of the heat-sensitive recording material of Comparative Example 3 was prepared in the same manner as in Example 1 except that 10 parts of 90 ML/100 g calcium carbonate and 10 parts of general silica were used in combination.

Comparative Example 4 In Example 4, liquid C used as the undercoat liquid was prepared using boiled linseed oil (JIS K-5101.1).
9>, 120 m/100 (instead of 20 parts of porous calcium carbonate with an oil absorption of 1 or more, in Ogura method-boiled linseed oil (JIS K-5101/19),
Using 90ML/100g of calcium carbonate, 120d/100 in liquid C, Xiaoyu-boiled linseed oil (JIS -5101-19), which is used as a heat-sensitive coloring liquid.
A heat-sensitive recording material of Comparative Example 4 was obtained in the same manner as in Example 4, except that ordinary silica was used instead of 20 parts of porous calcium carbonate having an oil absorption of 1.5 g or more.

Comparative Example 5 In Comparative Example 4, Ogura method boiled linseed oil (JIS K-5101.1) was used as the undercoat liquid.
9), instead of 20 parts of porous calcium carbonate with an oil absorption of 120nf/100g or more, Ogura-boiled linseed oil (JIS K-5101/19) uses 10 parts of 90of/loOg calcium carbonate and 10 parts of polystyrene. A heat-sensitive recording material of Comparative Example 5 was obtained in the same manner as Comparative Example 4 except that the following were used in combination.

Comparative Example 6 Example 1 except that 2-(2°-chloroanilino-6-di-N-butylaminofluoran) was used instead of 3-dibutylamino 6-methyl-7-anilinofluoran. A heat-sensitive recording material of Comparative Example 6 was obtained in the same manner as in Example 1.

The ten types of heat-sensitive recording materials obtained above were subjected to a color development test and a head matching test. In the color development test, each lean pull was printed using a G-In mode high-speed printing tester (applied voltage 14.0 W/dot, pulse width 0.4.0.
5.0.6m5eC) Background and image at L/T) Q degree was measured, and the state of adhesion of residue to the head was visually evaluated.

The results are shown below.

Claims (1)

[Claims] In a heat-sensitive recording material that utilizes a color reaction between a leuco dye and a color developer, Ogura-boiled linseed oil (JISK-510
1.19) is a heat-sensitive recording material characterized by containing porous calcium carbonate having an oil absorption of 120 ML/100 g or more.