JPS58166096A - Heat-sensitive recording body - Google Patents

Abstract

PURPOSE:To prevent the coloring of texture due to a white degree, heat, and humidity, by using a surface active agent of sulfuric ester salt series and sulfonate series as a dispersing agent of leuco dye. CONSTITUTION:As the dispersing agent of a colorless or light-colored leuco dye, a surface active agent of sulfuric ester salt series such as ester sulfate, alkyl sulfate, or ether sulfate or sulfonate series such as alkyl sulfonate, sulfosuccinate, or ester sulfonate is used to form a heat-sensitive recording body. About 1-20wt% said surface active agent is used for the leuco dye. For the purpose of improving the sensitivity and the shelf life of the heat-sensitive recording body, other waxes, aromatic ester derivatives, or the like can be used. Since the sulfuric ester and sulfonate surface active agent has highly excellent dispersion capability, the dispersing time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sensitive recording material, in which * is whiteness;
The present invention relates to a heat-sensitive recording material that has improved background coloring due to heat and humidity.

The thermosensitive recording material in the present invention includes an electron acceptor and W! Leuco dyes, which are usually colorless or pale in color when touched, develop a deep color when touched, organic acids, electron acceptors such as phenolic compound eyelids, and binders, l! A composition consisting of a sensitizer for adjusting color development sensitivity, inorganic powder, and various other auxiliary materials is applied to the support Kf1.
This is the one that came in first place.

Such heat-sensitive recording media information transmission systems have come to be widely used in medical and industrial needle-side fields, etc., and various improvements have been required in the crystalline mm. Higher sensitivity.

Improving the stitching characteristics by further heating with the thermal head? - $1 Abrasion prevention of Maru head, Na, Nihe, Nkaoya wearing [1h, Elafl &], Ground 05 Coloration prevention, Recording - Image fading prevention.

In order to improve this point, the inventors of the present invention conducted intensive studies on dispersants that act as auxiliary materials in heat-sensitive compositions, and found that sulfate ester salts and/or The present inventors have discovered that the whiteness can be significantly improved by using a sulfonate-based surfactant, and that skin discoloration due to heat and humidity can be prevented.

Generally, in order to produce a heat-sensitive recording medium, the color-forming component leuco dye, the color-developing component such as an electron acceptor such as a phenolic substance, and if necessary, a sensitivity modifier, an inorganic powder, etc. are prepared separately in separate kettles. A dispersion liquid is prepared by dispersing a mutually unmixable combination of a color-forming component and a color-developing component in water, the dispersion tube is further mixed with a binder, etc. to prepare a coating liquid, and the coating liquid is coated on a support for several kilometers. The most common method is to use the protective colloid effect of water-soluble polymers to disperse leuco dyes, electron acceptors as color components, etc. in water. It's true.

For example, cellulose fermentation conductors such as droxyethylcellulose, methylcellulose, carboxymethylcellulose, etc.
Starch derivatives such as cation/starch, hydrodiethyl starch, hydroxyglobil starch, phosphate esterified starch, carboxydimethyl starch, carboxyethyl starch, cyanoethylated starch, dialdehyde starch, gum arabic, gum tragacanth.

Locust bean gum, sodium alginate, soybean glue, natural vegetable molecules such as gluten, casein, glue,
Natural animal molecules such as gelatin, polyvinyl alcohol, partially saponified polyvinyl alcohol, polyvinyl pyrrolid/, polyacrylamide, polyacrylic acid, polymethacrylic acid and their salts, copolymers of acrylic acid, methacrylic acid, and the like. , styrene-maleic anhydride copolymers and their salts, and synthetic polymers such as polyvinyl methyl ether were used, and although they had a certain fractional ability, the viscosity of the dispersion was low. In addition to manufacturing problems such as long dispersion time, the color development rate is insufficient in terms of quality, and the whiteness is low.
Therefore, the present inventors conducted extensive research on the use of dispersants as shown in Japanese Patent Application No. 56-78692. Thus, it was anticipated that the use of a threatening acid ester salt and/or sulfonate-based surfactant would result in 1 shorter dispersion time, 1 higher color density, and improved sticking properties.

However, satisfactory effects were not obtained in terms of whiteness and coloring of the background due to heat and a degree.Therefore, the present inventors conducted further research on dispersants. The present invention was developed based on the expectation that only when a leuco dye or a sulfonate-based surfactant is used as a dispersant for leuco dye, whiteness will be significantly improved and skin discoloration due to heat and humidity can be prevented. The sulfuric ester salts and/or sulfuric acid salts of the present invention may be surfactants other than sulfonate surfactants, such as aliphatic ammonium salts and quaternary ammonium salts thereof.

Cation/surfactants based on aromatic quaternary ammonium salts; nonionic surfactants such as ethers, ether esters, esters, and nitrogen-containing types; sulfate ester salts and sulfonates among anionic surfactants; Compared to the heat-sensitive recording material obtained by dispersing leuco dye using the water-soluble ^ molecular dispersant described above, the surfactants such as carboxylic acid salt type and l/al ester salt type, etc. The heat-sensitive medium obtained by dispersing leuco dye using the sulfate ester salt-based or sulfonate-based surfactant of the present invention is extremely excellent in terms of whiteness and prevention of skin discoloration due to heat and moisture. It has a negative character.

In addition, the surfactants of the acid ester salt type and the sulfoyate type have extremely high fractional ability, and the dispersion time is shortened.
The effect of increasing the particle size and color development by 11 degrees was also observed.

Examples of the sulfate ester and sulfonate surfactants used in the present invention include ester sulfates, alkyl sulfates, and ether 1III! salt.

Allyl ether sulfate in alcohol, alcohol! acid salt,′
Sulfated oil, sulfonate in alcohol, sulfoconolinate, ester sulfonate, alkylaryl and luna 7 talenes sulfonate in alcohol, formalin condensed naphthalene sulfonate, N-acyl sulfo/acid, etc. 1 Usually sodium salt.

A mosquito surfactant that is used in the form of potassium salt or ammonium salt, but ammonium salt is better in terms of abrasion (corrosion) of the thermal head. Although the amount of addition is not limited to %, it is 1-jliO to leuco dye.
In addition, the above-mentioned water-soluble aphrodisiac molecules may not be used in combination with the purpose of supplementing the performance of the cough surfactant used for Wt skin, giving it a polymeric protective colloid effect, or increasing the viscosity. Of course it is possible.

It is also possible to use in combination an anionic surfactant such as salt-based or phosphate-based leuco dyes. Examples of colorless or light-colored leuco dyes used in the present invention include, for example, tritzelmethane-based leuco dyes. 8-bis-(p-dimethylaminophenyl) phthalide, 8.8-bis-(p-dimethylaminophenyl)-6-dimethylaminophthalide (crystal violet lactone), 8.8-bis-(p-dimethyl aminophenyl)-6-diethylamino 7-thallide,
4-Hydroxy-dimethylaminotriphenylmethane lactone, 4,4'-bisdihydroxy-8,8
-bisdiannotriphenylmethanelactone, etc., and fluorane-based 8-cyclohexylamino-6-chlorofluorane, 8-diethylamino-7-dipendyladenofluorane.

8-diethylamino-6-methyl-7-chloroptoluorane, 8-diethylamino-6-methyl-7-anilinofluorane, 8-diptylamino-6-methyl-7-anilinofluorane, 8. ? -bisdiethylaminofluorane, 8-diethylaminocoumethoxyfluorane,
8-diethylannault? - Chloranilinofluorane,
8-diethylamino-6-methyl-7-butylanilinofluorane, 8-(N-ethyl-p-)luidino)-〇-methyl-7-7nilino7, orane, 8-diethylamino-9-m-) Lifluoromethylanilinofluorane,
8-(N-Schiff-hexyl-N-methylamino)-6-
Methyl-7-anilinofluoranato, and 8-methyl-di-β-nathospiropyran of the spirovira y series, 1,
8.8-) Limethyl-〇'-chloro8'-methoxyi/dorinopenzospiropyrano, etc., and leuco dyes such as auramine, rhodamine lactam, fetchaziy, and phenooxazine are also used, but one The invention is not limited to these representative examples.

Electron acceptors used in the present invention include Il clay,
Non-acidic substances such as kaolin, zeolite, silicon oxide, aluminum silicate, and silicic acid.

! Organic acids such as leic acid, benzoic acid, salicylic acid, and gallic acid, their esters, and metal salts are also used, but they have low water solubility, have a sharp melting point of 70°C or higher (II), and cannot be mixed with leuco dyes. Preferred are phenolic compounds which have excellent properties. For example, 4-tart-butylphenol, 4-phenylphenol, 2,2-bis(4
-hydroxyphenyl)propane, 2,2-bis(4-
Hydroxyphenylene(2)-n-hebutane, 4,4'-impropylidene bis(2-chlorophenol), 4-isopropylidene bis(2-methylphenol), 4.
Eethylenebis(2-methylphenol), 1-1-
Examples include bix-(4-hydroxyphenyl)-cyclohexane. It is also possible to use a mixture of two or more of these electron acceptors. However, the present invention is not limited to these representative examples.・ - In addition, various improvements such as improving the sensitivity of thermal recording media, improving storage stability, improving whiteness, improving i & recordability, preventing sticking to thermal and recording heads, preventing scum from adhering, and improving coating properties for pressure buildup. For purposes, waxes.

Aromatic acid ester derivatives, metal soaps, amine-based/phenol-based antioxidants, benzophenol-based/benzotriazole-based ultraviolet absorbers, natural maldehyde etc.
Organic polymer powder such as tx, fluorescent dye.

Various auxiliary agents such as silicone 1IIfjl agents and alkyl heptadide activators can be added.

As waxes, for example, paraffin wax, microcrystalline wax, carnauba wax, polyethylene wax, polyglopylene wax, monk acid wax, and higher fatty acid amide wax are used.

Examples of aromatic acid ester derivatives include alkyl benzoate, allyl benzoate, alkyl-p-hydroxybenzony), 7Q-p-hydroxybenzoate, and alkyl-p-hydroxybenzoate.

Allyl salicylate, monoalkyl terephthalate, dialkyl terephthalate, dialkyl-2-methyl terephthalate, dialkyl-2-meth inorganic powders include:
clay, kaolin, talc.

Calcium carbonate, magnesium carbonate, charcoal @ zinc.

Calcium oxide, magnesium oxide, s! Zincide.

Titanium oxide, *aluminum oxide, silicon oxide, magnesium hydroxide, aluminum hydroxide, magnesium alumina hydroxide, magnesium silicate, aluminum silicate,
White carb/, magnesium alkinosilicate, etc. are used.

In addition, a binder is used to adhere these composition dispersions to each other and adhere them to the support. As a binder, most of the above-mentioned hydrophilic polymers are used, and cellulose derivatives are used. , starch derivatives, vegetable natural polymers, animal natural polymers and synthetic polymers are mainly used.

Furthermore, various water-resistant agents can be added to improve water resistance, and smoothness can also be increased.

As the support, paper 1 synthetic paper, glass film, etc. can be used, but paper is usually most often used from the viewpoint of M rating, #1 workability, etc.

Examples are shown below to explain the present invention in more detail, but the present invention is of course not limited to these.

Examples 1-8 Comparative Examples 1-8 E Polyvinyl Alcohol 1091 Watermelon Fluid 10
0 copies, and further processed in a super calender to give a Beck smoothness of about 800 seconds to obtain a heat-sensitive recording paper.

[Margin below]

Examples 9 to 18 Comparative Examples 9 to 17 EIIl esterification 20% aqueous solution 5
o part F')7sl)-5, o, water ■
Each of the compositions of sliding parts A to D was dispersed with a dispersant using a sandguno grinder to form a dispersion liquid, and the above formulation was mixed and stirred to prepare a coating liquid.◎This! K11k processing and drying on high-quality So-Sea paper to a dry weight of 6 sheets, and then using a super calender to achieve a Beck flatness of approximately 50 sheets.
A thermosensitive recording paper was obtained by surface treatment so that the temperature was 0 seconds.

Table 2 Examples 14-22 Comparative Examples 18-26 FFIAM min 8
〒 Silicone Emulsion Expansion O,5SA
-D each composition was dispersed in a Bibi dispersant and ingredients using an attritor to prepare a dispersion liquid, and the above formulation was mixed and stirred to prepare a coating liquid. Dry weight '1' of this on 64 t/d high-quality paper
It is processed and dried so that it becomes VtK, and then surface treated using a super calender to achieve Beck smoothness of approximately 600 seconds, making it suitable for thermal recording paper.

Table 8 Example 23 Each composition was dispersed with a sand grinder together with a dispersant to obtain a dispersion liquid, and the above formulation was mixed and stirred to prepare a coating liquid. This was coated and dried on a 50-sheet high-quality paper to a dry weight of 6 sheets, and further treated with a super calender to give a Beck smoothness of about 800 seconds to obtain a one-heat recording paper. .

Comparative Examples 27 to 80' In Example 28, the dispersant shown in Table 4 was used instead of ammonium dodecylbenzenesulfonate as the dispersant for liquid A, and except for 9, thermal recording was carried out in the same manner as Example 1 if J. Obtained paper @ good wind example 1-28. The evaluation results of the thermal recording papers obtained in Comparative Examples 1 to 80 are shown in Tables 5 to 8. It is clear from the tables that the whiteness of the examples of the present invention is high.

A good product was obtained with little skin discoloration due to heat and humidity. It can be seen that Q for the wear of the Mayu head is good even when an ammonium salt type dispersant is used.

[Margin below]

Table 5 Table 6 Table 7 Table 8 Each evaluation item was measured as follows.

White f: Measured with a Hunter whiteness meter Profilter.

Skin layer f: Early summer skin density, 4 under the environmental condition of 160°C
After leaving for 8 hours, the background density of 9 heat-sensitive recording paper, 150℃, 80
Background density and development Ap2 of thermal recording paper left for 48 hours under 1RH environmental condition: Heating: 11 floo degrees Celsius, contact pressure: 250 f/
d.

Image 1i of thermal recording paper developed under conditions of heating time of 8 seconds
ly.

Background density 0 color once Macbeth reflection dark needle RD-514
Measured using [Wratten #106 filter].

Head wear: 100% of thermal recording paper is printed using a long-distance printing device.
The print was run for 00 m, and the amount of wear on the thermal head before and after that was measured using a surface roughness tester.

Patent issuer Kojin Co., Ltd.

Claims (1)

[Claims] ω Colorless or light-colored roy; thermal recording material K having a coloring layer containing a dye and an electron acceptor that causes the dye to color when heated
T? It is characterized by using an am ester salt type and /l or sulfonate type surfactant as a dispersant for the TYIco dye.
The heat-sensitive recording material according to claim 1, characterized in that a natural, semi-synthetic or synthetic water-soluble polymer is used in combination as a dispersant for the leuco dye. (8) A patent claim characterized in that the sulfate ester salt-based and/or sulfonate-based surfactant is an ammonium salt. body.