JPS60248390A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a thermal recording material enhanced in heat response characteristics, wherein a thermal color forming layer comprising a leuco dye and a color developer and a hollow minute particle containing layer as an undercoat layer for the color forming layer are provided on a base. CONSTITUTION:Hollow minute particles of a glass or the like are applied to the base together with a binder, e.g., polyvinyl alcohol, followed by driving to provide the undercoat layer. A coating liquid for forming the thermal color forming layer obtained by dispersing a leuco dye, e.g., 3,3-bis(p-dimethylaminophenyl) phthalide, a color developer, e.g., gallic acid and, optionally, a binder (e.g., polyvinylalcohol), a filler (e.g., calcium carbonate), a heat-fusible substance (e.g., a higher fatty acid), a surfactant or the like in a dispersing machine is applied to the undercoat layer, followed by drying and calendering to obtain the objective thermal recording material. EFFECT:Since a highly heat-insulating undercoat layer is provided, heat response characteristic is extremely high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat-sensitive recording material that utilizes a color-forming reaction between a leuco dye and a color developer.

[Prior art]

Conventionally, various heat-sensitive recording materials have been known in which a heat-sensitive coloring layer containing a leuco dye and a color developer is provided on a support.
This product records a colored image just by heating the instep, and is used for computer output, printers such as calculators, medical measurement recorders, facsimiles, automatic ticket vending machines, thermal labels, thermal copying, etc. Widely used. However, in the case of recording methods using such heat-sensitive recording materials, one of the drawbacks is that
One example of this is that the recording speed is slow compared to electrostatic recording methods and the like. Until now, the direction of this recording speed 1-1, that is,
Various Jj methods have been proposed to improve the heat responsiveness of the heat-sensitive coloring layer, such as incorporating a heat sensitizer into the heat-sensitive coloring layer, but these methods are not yet satisfactory.

[Object 11] An object of the present invention is to provide a heat-sensitive recording material with improved thermal responsiveness by providing a special protective layer.

〔composition〕

According to the present invention, in a support provided with a heat-sensitive coloring layer containing a leuco dye and a color developer, a hollow fine particle-containing layer is provided as an opposite layer to the thermosensitive coloring layer. A heat-sensitive recording material is provided.

In the present invention, various conventionally known hollow particles can be used as the hollow particles used in the underlayer.

Such items include, for example, glass, ceramics,
Examples include hollow bodies (balloons) made of various materials such as plastic. Conventionally, it has been known to provide a layer containing various fillers as an underlayer, but in the case of the present invention, the purpose is achieved by using the hollow fine particles as at least a part of the filler. I can do it.

The underlayer according to the present invention can be formed by coating the above-described hollow particles together with a binder on a support and drying. In this case, the particle size of the hollow particles is
Usually, it is less than lOILm, and the finer the particles, the more desirable. Further, in the present invention, the hollow fine particles can also be used in combination with various fillers that are conventionally used in general paper manufacturing.

As such a filler, for example, Calcilla carbonate 1
1, kaolin, talc, zinc oxide, aluminum hydroxide, silica, magnesium silicate, polystyrene resin, urea-formaldehyde resin, etc. When hollow particles are used in combination with such a filler, the mixing ratio is not particularly limited, but generally the filler is
It is used in a proportion of 1 to 10 parts by weight per 1 part by weight of the hollow particles. Further, as the binder applied to the underlayer, generally known water-soluble polymers or aqueous emulsions are used, and specific examples include those shown below.

Polyvinyl alcohol, methyl cellulose, diethyl cellulose, thiazine, starch derivative, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyamide 1~, sr+++ latex, polystyrene-acrylic acid ester emulsion,
Polyhinyl acetate emulsion etc.

In the underlayer according to the present invention, the content of the binder is about 10 to 90% by weight based on the total solid content.

The underlayer according to the present invention improves the thermal responsiveness of the thermosensitive coloring layer provided thereon.

The heat-sensitive color forming layer of the present invention is mainly composed of a leuco dye and a color developer, and the leuco dyes can be applied alone or in a mixture of two or more kinds. Any dye that is used in recording materials may be used, and leuco compounds of dyes such as triphenylmethane, fluoran, phenothiazine, auramine, and spiropyran dyes are preferably used. Specific examples of such leuco dyes include those shown above.

3.3-His(p-dimethylaminophenyl)-phthalide, 3.3-bis(P-dimethylaminophenyl)-6-dimethylaminophthalide 1 (also known as crystal violet lactone), 3.3-His(P -dimethylaminophenyl)-6-ethylaminophthalito, 3.3-his(l)-dimethylaminophenyl)-6-
Chlorphthalide, 3.3-bis(P-dibutylaminophenyl)phthalide 1
-5 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane.

3-diethylamino-7-talolofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-hensfluorane, 3-diethylamino-
6-Methyl-7-chlorofluorane.

3-(N-pt~ly-N-ethylamino)-6-methyl-7-anilinofluorane, :3-pyrrolisino6-methyl-7-anilinofluorane, 2-(N-(3' -1-lifluoromethylphenyl)amino)-6-ethylaminofluorane, 2-(co,6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lacta td, 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-
Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N- diethylamino)-5-methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-henziintrinopyrillospirane, 6'-bromo-3'-me1-xy-henziintrinopyrillospirane , 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)-1-(2'-methoxy-5'-methylphenyl)phthalide, 3-(2 '-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5'
-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N -hensyl-trifluoromethylanilino)fluoran, 3-pyrrolisino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chloro-7-(α-)engineered methylethylamino)fluoran, 3 -(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(0-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-(α -)Dylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-n
-butylanilino)fluoran, 3-(N-benzyl-cyclohexylamino)-5゜6
-Penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
', 5'-benzofluorane, etc.

In addition, as the color developer used in the present invention, various electron-accepting substances that react with the leuco dye and develop color when heated are used. Examples include f1 substances, organic or inorganic acidic substances, or salts thereof.

gallic acid, salicylic acid, 3-isopropylsalicylic acid,
3-cyclohexylsalicylic acid, 3,5-dicert
, -butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4'-isopropylidenediphenol, 4,4'-isopropyritine bis(2-chlorophenol), 4,4'-isopropyritine bis (2,6-
cypromophenol), 4,4'-isopropylidene bis(2,6-dichlorophenol), 4゜4'-isopropyritine bis(2-methylphenol), 4,4'-
Isopropylidene bis(2,6-cynotylphenol)
, 4,4'-inpropylidene bis(2-terL-butylphenol), 4,4'-5ec-butylidene diphenol, 4,4'-cyclohexylidene bisphenol, 4,4'-cyclohexylidene bis(2 -methylphenol), 4-t, ert-butylphenol, 4
-Phenylphenol, 4-hydroxycyphenoxyto, α-naphthol, β-naphthol, 3,5-xylenol, thymol, methyl-4-hydroxynzoe-1~
, 4-hydroxyace1-phenone, novolac type phenolic resin, 2,2'-thiobis(4,6-dichlorophenol), catechol, resorcinol, hydroquinone,
Pyrogallol, phloroglycine, phloroglycin carboxylic acid, 4-t; ert-octylcatechol, 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 -p-chlorobenzyl hydroxybenzoate, 0-chlorobenzyl p-hydroxybenzoate, P-methylbenzyl p-hydroxybenzoate,
n-octyl p-hydroxybenzoate, benzoic acid, zinc salicylate, 1-hydroxy-2-naphthoic acid, 2-
Hydroxy-6-naphthoic acid, zinc 2-hydroxy-6-naphthoic acid, 4-hydroxydiphenylsulfone, 4
-Hydroxy-4'-chlorodiphenyl sulfone, bis(4-hydroxyphenyl) sulfide, 2-hydroxy-p-toluic acid, 3,5-di-butyltin salicylate, tartaric acid, oxalic acid, maleic acid, citric acid, Succinic acid, stearic acid, 4-hydroxyphthalic acid, boric acid, etc.

In the present invention, in order to bind and support the leuco dye and color developer on the support, various commonly used binders can be used as appropriate, such as polyvinyl alcohol, starch and its derivatives, methoxycellulose, hydroxyl, etc. Cellulose derivatives such as ethyl cellulose, carboxymethyl cellulose, methyl cellulose, and ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, acryl amide/acrylic ester/methacrylic acid ternary copolymer, styrene/ Maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer alkali salt,
In addition to water-soluble polymers such as polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride/vinyl acetate copolymer, Latex such as polybutyl methacrylate, ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, 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, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, etc.
1. In addition to inorganic fine powders such as zinc hydroxide, palliu 11 sulfate, clay, talc, surface-treated Calcilla 11 and silica, organic fine powders such as urea-formalin resin, styrene/methacrylic acid copolymer, and polystyrene resin. Examples of thermofusible substances include higher fatty acids or their esters, amino acids or metal salts, various waxes, condensates of aromatic carboxylic acids and amines,
An 79, fragrant phenyl ester, higher linear glycol,
dialkyl 3,4-epoxy-hexahydrophthalate,
50~ of high grade canes, other thermofusible organic compounds, etc.
Examples include those having a melting point of about 200°C.

Generally known methods can be used to obtain the heat-sensitive recording material of the present invention. That is, leuco dye, color developer, binder, and other additives are mixed together, or components other than the leuco dye are mixed to form a protective colloid such as polyvinyl alcohol.
After adding substances, surfactants, etc. and dispersing them using a dispersing machine such as a ball mill, attritor, or Sun 1-mill, prepare a heat-sensitive coloring layer coating solution according to the prescription, apply it to the undercoat layer, and dry it. After that, the heat-sensitive recording sheet of the present invention is obtained by applying a calendar.

In addition, the heat-sensitive recording material of the present invention may be provided as a protective layer in the heat-sensitive coloring layer 1, depending on the tendency of the heat-sensitive recording material to interact with a thermal pen or heat head, etc., or for the purpose of further enhancing the storage stability of recorded images. In this case, the components constituting the protective layer may include the filler binder, surfactant, thermofusible substance (lubricating agent), and the like.

〔effect〕

Since the heat-sensitive recording material of the present invention contains hollow particles as a filler in the under layer, it is possible to form an under layer with unprecedentedly high heat insulation properties, and has extremely high thermal responsiveness. .

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. In addition, all the parts shown below are based on ff:.

Examples 1 to 2 Solutions [A] to ([E] were prepared by dispersing a mixture of the following components using a sand grinder for 2 hours.

[A] Foamed hollow fine particles of liquid borosilicate glass Lunar 1 to Lieu 11 salt 20 parts 10% polyhinyl alcohol water i6M 2On water 60
! ! [B] Liquid aluminosilicone group 1 - foam hollow particles - 20 parts 10%
Polyvinyl alcohol water 60+1 (C) Liquid Calcilla carbonate 1120 parts 10% polyvinyl alcohol aqueous solution 20+1 Water 60
Il CD) Liquid 3-(N-methyl-N-cyclohexyl)amino-6-
Methylanilinofluorane 20 parts 10% polyvinyl alcohol aqueous solution fi 207I water 60n [E] Solution P-benzyl hydroxybenzoate 10 parts Calcium carbonate ]011 10% polyvinyl alcohol aqueous solution 2011 water 60
! ! Next, [A] solution and [r. ) were mixed and stirred at a weight ratio of 3:2 to prepare [F] solution, and CB] and [C
Prepare solution [G] by mixing and stirring solution D at a weight ratio of 3:2, and then mix solution CD) and solution [E) at a weight ratio of 1:8.
A liquid [11] was prepared by mixing and stirring the mixture so that the following results were obtained.

These undercoat layer coating solution [F] or CG) and thermosensitive coloring layer coating solution [11] were coated on high-quality paper with a basis weight of 52H/rri', and the undercoat layer was 5 g/m in dry weight, and the thermosensitive coloring layer was 5 g/m in dry weight. Two types of heat-sensitive recording materials of the present invention were prepared by coating and drying according to the contents of Table 1 to give a coating thickness of 5 to 6 [X/m2, and then calendering to obtain a flatness of 500 to 300 seconds. did.

Table-1 Comparative Example 1 In addition, in order to compare with Examples, the contents of Table-2 were compared using the method described in Example and Ii using CD liquid and heat-sensitive coloring layer coating liquid [11] described in n11. Two types of example vJ products were created.

A test of thermal responsiveness (dynamic color development sensitivity) was conducted on 14 types of heat-sensitive recording materials shown in Table 2 below. The results are shown in Table-3.

The test method was as follows.

Dynamic color development sensitivity: Power 0.45 W/ to Yatsu 1 using a thermal printing experimental device manufactured by Matsushita Electronics Components and equipped with a thin film Hen 1.
Dot, one line recording time 20 ms/(1., pulse 1 under conditions of scanning line density 8 x 3.851-sol-/mm) of 0.8, 1.0, 1.2.

1, 4, 1.6 and ], 8 msec, and the density of the [l] character was measured with a Machess densitometer HD-514 (Filter Lee 106).6 Table 3 From the results shown in Table 3, As shown above, the heat-sensitive recording material of the present invention has no under layer (Comparative Example 1)
It can be seen that not only the thermal responsiveness (dynamic coloring sensitivity) is significantly higher than that of the previous layer, but also that it is superior to the case where a conventionally known general filler is used as the underlayer filler (Comparative Example 2).

Patent Applicant Stock Monthly” - Attorney attorney 1/l! l Toshiaki Ura

Claims (1)

[Claims] (1) A heat-sensitive recording characterized in that a heat-sensitive coloring layer containing a leuco dye and a color developer is provided on a support, and a hollow fine particle-containing layer is provided as an under layer to the heat-sensitive coloring layer. material.