JP2808148B2 - Thermal recording material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat-sensitive recording material, and more particularly, to a heat-sensitive recording material with little curl.

[Prior Art] A general heat-sensitive recording material is a colorless or pale-colored dye such as a leuco dye as a color former on a support such as paper or a film, and a phenolic compound (especially as a developer for thermally coloring the dye). A thermosensitive coloring layer in which a binder, a filler, a sensitivity improving agent, a lubricant and other auxiliaries are further dispersed is provided on a coloring system composed of an acidic substance such as bisphenol A) and an organic acid. These materials are introduced in, for example, JP-B-43-4160, JP-B-45-14039, and JP-A-48-27736, and are widely used.

This type of heat-sensitive recording material obtains a color image by an instantaneous chemical reaction between a color developer and a developer when heated (a thermal printer or a facsimile with a built-in thermal head is used for heating). Therefore, compared to other recording materials, there is an advantage that recording can be obtained in a relatively short time in a relatively simple apparatus without performing complicated processing such as development and fixing, and the cost is low. In addition to being used for copying documents and the like, it is applied to a wide range of fields such as electronic calculators, facsimile machines, telex, medical measuring machines, automatic ticket vending machines, and bar code labels. However, recently, as these recording apparatuses have been diversified and their performance has been advanced, the required quality of the heat-sensitive recording material has also become higher.

For example, in recent years, thermosensitive recording materials used for facsimile machines are usually wound around a paper tube having an inner diameter of 1 inch or less for compactness. Therefore, there is a demand for a heat-sensitive recording material having little curl.

[Problems to be Solved by the Invention] An object of the present invention is to provide a thermosensitive recording material having little curl.

[Means for Solving the Problems] The structure of the present invention for solving the above-mentioned problems is that a heat-sensitive recording material provided with a thermosensitive coloring layer containing a leuco dye and a color developer on a support has a structure in the support. A heat-sensitive recording material characterized by being impregnated with a polyethylene glycol alkylphenyl ether represented by the following general formula.

General formula R represents an alkyl group having 5 to 20 carbon atoms, and n represents an integer of 20 to 40.

The heat-sensitive recording material of the present invention contains polyethylene glycol alkyl phenyl ether in the support,
A thermosensitive recording material with little curl can be obtained.

In the present invention, the polyethylene glycol alkylphenyl ether contained in the support has an alkyl group having 5 to 20 carbon atoms, n is an integer of 20 to 40, and is a solid or paste at room temperature.

When n is 19 or less, the permeability is too good, so that it penetrates to the heat-sensitive coloring layer, and the background fog occurs. When n is 41 or more,
It does not reduce curl.

The amount of polyethylene glycol alkyl phenyl ether impregnated in the support is 0.01 to 5 g / m ² , preferably 0.1 to 0.5 g / cm ² . If it is less than 0.01 g / m ² , there is no effect of reducing curl. If it exceeds 5 g / m ² , it is finished in a roll shape and transfers to the heat-sensitive coloring layer over time, causing background fogging.

As a method of impregnating the support with polyethylene glycol alkyl phenyl ether, it is preferable to apply to the surface of the support opposite to the thermosensitive coloring layer, but it may be added in advance in the papermaking process, or may be added in the size press process. Any method may be used as long as it can be impregnated in the support.

In the present invention, a heat-sensitive color-developing layer mainly comprising a commonly used known leuco dye and a developer is provided on the support thus treated.

The leuco dye used in the present invention may be used alone or
Such leuco dyes are applied as a mixture, and any of those applied to this type of heat-sensitive recording material may be arbitrarily applied.For example, triphenylmethane, fluoran, phenothiazine, auramine Leuco compounds of various dyes such as a dye, a spiropyran and an indolinophthalide are preferably used. Specific examples of such leuco dyes include, for example, those shown below.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethyl Aminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-N-methyl-N-isobutyl-6-methyl-7-
Anilinofluoranamino-5,7-dimethylfluoran, 3-N-methyl-N-isoamyl-6-methyl-7-
Anilinofluoranamino-5,7-dimethylfluoran, 3,3-bis (p-dibutylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethylamino Phenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-5,7-dimethylfluoran, 3-diethylamino-7 -Chlorofluorane, 3-diethylamino-7-methylfluoran, 3-diethylamino-7,8-benzfluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3- (Np-tolyl- N-ethylamino) -6-methyl-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofur Orchid, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluoran, 2- {3,6-bis (diethylamino) -9- (o-chloroanilino) xanthyl lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluoran, 3-diethylamino-7- (o-chloroanilino) fluoran, 3-dibutylamino-7- (o-chloroanilino) fluoran, 3-N -Methyl-N-amylamino-6-methyl-7
-Anilinofluoran, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- (N, N- Diethylamino) -5-methyl-7-
(N, N-dibenzylamino) fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-
Pyrirospiran, 6'-bromo-3'-methoxy-benzoindolino-
Pyrirospiran, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl)- 3- (2'-methoxy-5'-nitrophenyl) phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl) phthalide, 3- ( 2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-
Methylphenyl) phthalide, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-tetrahydrofurfuryl) amino-6-methyl-7- Anilinofluoran, 3- (N-ethyl-N-ethoxypropyl) amino-
6-methyl-7-anilinofluoran, 3- (N-methyl-N-isopropyl) amino-6
Methyl-7-anilinofluoran, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-trifluoromethylanilinofluoran, 3-diethylamino-5-chloro- 7- (N-benzyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluoran, 3-diethylamino-5-chloro-7- (α-phenylethylamino ) Fluoran, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluoran, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl- 7- (α-phenylethylamino) fluoran, 3-diethylamino-7-pi Rijinofuruoran, 2-chloro-3-(N-Mechirutoruijino) -7-
(Pn-butylanilino) fluoran, 3- (N-benzyl-N-cyclohexylamino)-
5,6-benzo-7-α-naphthylamino-4′-bromofluoran, 3-diethylamino-6-methyl-7-mesitidino-
4 ', 5'-benzofluoran, 3,6-dimethoxyfluoran, 3- (p-dimethylaminophenyl) -3-phenylphthalide, 3-di (1-ethyl-2-methylyldol) -3 −
Yl-phthalide, 3-diethylamino-6-phenyl-7-azafluoran, 3,3-bis (p-diethylaminophenyl) -6-dimethylaminophthalide, 2-bis (p-dimethylaminophenyl) methyl-5
-Dimethylamino-benzoic acid, 3- (p-dimethylaminophenyl) -3- (p-dibenzylaminophenyl) phthalide, 3- (N-ethyl-NN-aluminum) amino-6-methyl-7 -Anilinofluoran, 3-N-methyl-N-isobutyl-6-methyl-7-
Anilinofluoran, 3-N-ethyl-N-isoamyl-6-methyl-7-
Anilinofluoran, 3-diethylamino-6-methyl-7- (2 ', 4'-
Dimethylanilino) fluoran and the like.

Further, as the developer used in the present invention, various electron-accepting substances that react with the leuco dye upon heating to develop the color are applied, and specific examples thereof include phenols as shown below. And organic or inorganic acidic substances or their esters and salts.

Gallic acid, salicylic acid, 3-isopropylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-di-tert-
Butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4′-isopropylidene diphenol, 4,4 ′
-Isopropylidenebis (2-chlorophenol), 4,
4'-isopropylidenebis (2,6-dibromophenol), 4,4'-isopropylidenebis (2,6-dichlorophenol), 4,4'-isopropylidenebis (2-methylphenol), 4,4 '-Isopropylidenebis (2,6-
Dimethylphenol), 4,4'-isopropylidenebis (2-tert-butylphenol), 4,4'-sec-butylidenediphenol, 4,4'-cyclohexylidenebisphenol, 4,4'-cyclohexylidenebis (2-methylphenol), 4-tert-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, α
-Naphthol, β-naphthol, 3,5-xylenol,
Thymol, methyl-4-hydroxybenzoate, 4-
Hydroxyacetophenone, novolak phenolic resin, 2,2'-thiobis (4,6-dichlorophenol), catechol, resorcin, hydroquinone, pyrogallol,
Phloroglysin, phloroglysin carboxylic acid, 4-tert
-Octyl catechol, 2,2'-methylenebis (4-chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-dihydroxydiphenyl, ethyl p-hydroxybenzoate, Propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate, o-chlorobenzyl p-hydroxybenzoate, p-hydroxybenzoic acid
p-methylbenzyl, p-hydroxybenzoic acid-n-octyl, benzoic acid, zinc salicylate, 1-hydroxy-
2-naphthoic acid, 2-hydroxy-6-naphthoic acid, 2
-Hydroxy-6-naphthoic acid zinc, 4-hydroxydiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 2-hydroxy-p-toluic acid, 3,5-di- t
Zinc ert-butylsalicylate, tin 3,5-di-tert-butylsalicylate, tartaric acid, oxalic acid, maleic acid, citric acid, succinic acid, stearic acid, 4-hydroxyphthalic acid, boric acid, thiourea derivative, 4- Hydroxythiophenol derivative, bis (4-hydroxyphenyl) acetic acid,
Methyl bis (4-hydroxyphenyl) acetate, bis (4
-Hydroxyphenyl) ethyl acetate, n-propyl bis (4-hydroxyphenyl) acetate, n-butyl bis (4-hydroxyphenyl) acetate, phenyl bis (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate Phenethyl bis (4-hydroxyphenyl) acetate, bis (3-methyl-4-hydroxyphenyl) acetic acid, methyl bis (3-methyl-4-hydroxyphenyl) acetate, bis (3-methyl-4-hydroxyphenyl) acetic acid Ethyl, n-propyl bis (3-methyl-4-hydroxyphenyl) acetate, 1,7-bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-
Di (4-hydroxyphenylthio) -3-oxapentane, dimethyl 4-hydroxyphthalate, 4-hydroxy-4'-methoxydiphenylsulfone, 4-hydroxy-4'-ethoxydiphenylsulfone, 4-hydroxy-4'- Isopropoxydiphenyl sulfone, 4-hydroxy-4'-n-propoxydiphenyl sulfone, 4
-Hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4'-n-butoxydiphenylsulfone, 4-hydroxy-4'-isobutoxydiphenylsulfone, 4-hydroxy-4'-sec-butoxydiphenylsulfone, 4-hydroxy-4'-tertbutoxydiphenylsulfone, 4-hydroxy-4'-benzyloxydiphenylsulfone, 4-hydroxy-4'-phenoxydiphenylsulfone, 4-hydroxy-4'-
(M-methylbenzyloxy) diphenyl sulfone, 4-
Hydroxy-4 '-(P-methylbenzyloxy) diphenylsulfone, 4-hydroxy-4'-(o-methylbenzyloxy) diphenylsulfone, 4-hydroxy-
4 '-(p-chlorobenzyloxy) diphenyl sulfone.

To produce the thermosensitive recording material of the present invention, a leuco dye,
The developer and the auxiliary component may be bonded and supported on a support. Specific examples of such a binder include the following.

Polyvinyl alcohol, starch and derivatives thereof, hydroxymethyl cellulose, hydroxyethyl cellulose,
Cellulose derivatives such as carboxymethylcellulose, methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene / maleic anhydride copolymer Alkali salts, isobutylene / maleic anhydride copolymer alkali salts, water-soluble polymers such as polyacrylamide, sodium alginate, gelatin, casein, polyvinyl acetate, polyurethane, polyacrylic acid,
Emulsions such as polyacrylates, vinyl chloride / vinyl acetate copolymers, polybutyl methacrylate, ethylene / vinyl acetate copolymers, and latexes such as styrene / butadiene copolymers and styrene / butadiene / acrylic copolymers.

In the present invention, if necessary, auxiliary additives commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, and heat-fusible substances (or lubricants) can be used in combination. In this case, as the filler, for example, other than inorganic fine powder such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated calcium and silica, etc. And urea-folimarin resin, styrene / methacrylic acid copolymer, polystyrene resin, and other organic fine powders. Examples of the heat-fusible substance include stearic acid amide, behenic acid amide, and ethylene bis. Stearyl amide, methylene bisstearyl amide, p
-Benzyl-biphenyl, m-terphenyl, p-methoxycarbonyloctadecylcarbamoylbenzene, 1
Phenyl-hydroxy-2-naphthoate, ethylenebis (m-methylphenyl) ether, β-naphthylbenzylether, and the like. Generally, a white substance having a melting point of about 50 to 150 ° C. and low water solubility is used.

Incidentally, the heat-sensitive recording material of the present invention can be provided with a protective layer on the heat-sensitive coloring layer for the purpose of improving the matching property with a thermal head or the like, and further improving the storage stability of the recorded image. In this case, the above-mentioned filler, binder, surfactant, and heat-fusible substance can also be used as components constituting the protective layer.

[Examples] Next, the present invention will be described in more detail with reference to examples. In addition, all parts and% shown below are based on weight.

Example 1 A mixture having the following formulation was pulverized in a magnetic ball mill for 2 days to prepare a solution [A], a solution [B] and a solution [C].

[A] Liquid formulation 3- (methyl-N-cyclohexylamino) -6-methyl-7-anilinofluoran 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [B] Liquid formulation benzyl p-oxybenzoate 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [C] liquid formulation Calcium carbonate 20 parts 5% aqueous solution of methylcellulose 20 parts Water 60 parts Next, [A] liquid 10 parts, [B] liquid 30 parts, [C] 30 parts of a liquid and 10 parts of a 20% aqueous solution of an isobutylene-maleic anhydride copolymer were mixed to form a thermosensitive color-forming layer forming solution, which was dried on wood free paper having a basis weight of 50 g / m ² and a dye adhesion amount of 0.5 after drying. g / m ² with a wire bar, dried in an oven at 50 ° C., and applied with an aqueous solution of each of the compounds shown in Table 1 on the backside after drying to an amount of 0.3 g / m ² . Apply with a wire bar and dry in a 50 ° C oven .

Further, the surface of the heat-sensitive coloring layer was calendered so that the surface smoothness became 500 to 600 sec to prepare a heat-sensitive recording material.

Examples 2 to 4 Heat-sensitive recording materials were prepared under the same conditions as those of Example 1 except that the compounds applied to the back surface of the heat-sensitive recording material of Example 1 were changed to those shown in Table 1.

Comparative Examples 1 to 4 Thermosensitive recording materials were produced under the same conditions as those of the examples except that the material applied to the back surface of each of the above examples was changed to that shown in Table 1.

The samples prepared in each of the above examples and comparative examples were wound around a 1-inch paper tube having an outer diameter of 37 m / mφ at 20 ° C. and 60% R.
After leaving at H for 5 months, the curl of the core was measured.

It was left in an oven at 60 ° C. for 24 hours, and stains on the background were observed. Measurement of curl immediately after cutting the core portion A ₄ size, the average of the four corners of the height.

From the results shown in Table 1, it is clear that the thermosensitive recording medium according to the present invention has little curl and good storage stability.

[Effects of the Invention] As described above, the heat-sensitive recording material of the present invention has a structure in which a polyethylene glycol alkyl phenyl ether is contained in a support so that it can be wound for a long time on a paper tube having an inner diameter of 1 inch or less. In the core part after
It is a state in which the curl is small.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-218184 (JP, A) JP-A-61-139482 (JP, A) JP-A-60-184875 (JP, A) JP-A-58-1984 89395 (JP, A) JP-A-64-40691 (JP, A) JP-A-60-202732 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41M 5 / 28-5 / 34 D21H 1/00-3/82

Claims (1)

(57) [Claims] In a heat-sensitive recording material having a heat-sensitive coloring layer containing a leuco dye and a color developer on a support, the support is impregnated with polyethylene glycol alkylphenyl ether represented by the following general formula. Characteristic thermal recording material. General formula R represents an alkyl group having 5 to 20 carbon atoms, and n represents an integer of 20 to 40.