JPS6068991A - Two-color thermal recording material - Google Patents

Abstract

PURPOSE:To provide the titled material improved in color separation and free of mixing of colors in a high-temperature developed color image, by a method wherein a high-temperature color forming layer, an intermediate layer comprising a specified decolorizing agent and a low-temperature color forming layer comprising a leuco dye and a specified thiourea derivative are laminated on a base. CONSTITUTION:A liquid for forming a high-temperature thermal color forming layer comprising a leuco dye and a phenolic compound is applied to the base, followed by drying. Next, a liquid for forming an intermediate layer comprising a decolorizing agent of formula I , wherein X is formula II, III or the like, e.g., 4,4'-dithiodimorpholine, formula IV, wherein Y is formula V, VI or the like and R is alkylene, or formula VII, wherein Z is phenyl or higher alkyl, is applied to the high-temperature color forming layer, followed by drying. Then, a liquid for forming a low-temperature thermal color forming layer comprising a leuco dye and a thiourea derivative of formula VIII, wherein each of R1 and R2 is H, halogen, trifluoromethyl or the like, e.g., 3,3'-dichlorophenylthiourea, is applied to the intermediate layer, and is dried to obtain the objective material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an Icoco two-color heat-sensitive recording material.

[Prior art]

A thermosensitive recording material is a material in which a thermosensitive coloring layer capable of forming a colored image by heating is provided on a support such as paper, and a thermal printer equipped with a thermal head is widely used for heating.

Such conventional heat-sensitive recording materials include a colorless or light-colored leuco dye (color-forming main agent) having a rafton ring, a lactam ring, a spiropyran ring, etc. in the heat-sensitive coloring layer, and a heating +1i
The one that contains a color developer (color development aid) in 5' that reacts with this leuco dye to develop color has a different color tone! 1[Y Ming,
Moreover, it is widely used because it causes less fogging.

By the way, heat-sensitive recording materials can easily produce colored images just by heating them, so they are not only used as scales for copying books and documents, but also for recording various types of information such as electronic 81 calculators, facsimile machines, telex machines, and the output records of tid+q machines. However, depending on the purpose of recording, in order to display particularly necessary data or numbers more clearly, it is possible to record by changing the color of that part (display color) from the color of other parts. Of course, it is desirable to be able to do so.

Recently, attempts have been made to obtain multicolor recording paper using differences in heating temperature or thermal energy, and various multicolor thermosensitive recording papers have been proposed. ing. , multicolor thermosensitive recording paper is generally formed by overlapping two types of high-temperature and low-temperature coloring ff') that develop different tones with different coloring heat energies on a support, and can be broadly classified into: It can be divided into the following two types. One of them is to mix the colors of the low-temperature color-forming layer when coloring the high-temperature color-forming layer to obtain a color tone different from the color tone of the low-temperature color-forming layer.
The other method is to use a decoloring agent that decolorizes the low-temperature color-forming layer when coloring the high-temperature color-forming layer to obtain only the color tone of the high-temperature color-forming layer without color mixing of the color tone of the low-temperature color-forming layer. As a specific example of these, those of the composer are
Publication, Special Publication No. 49-43/12, Special Publication No. 19-2
7708, JP-A-48-86543, JP-A-4! It is described in No. 1-65239, etc., and the later 2 ft.
.

These include Japanese Patent Publication No. 50-17865, q.h.
This method is disclosed in Japanese Patent Publication No. 8048, Japanese Patent Application Laid-Open No. 53-47843, and the like.

However, in the case of the former multicolor thermosensitive recording paper,
During high-temperature coloring, the specific color tones that can be achieved in order to mix the color with the color tone of the low-temperature coloring layer are limited to black threads that have a strong high-temperature coloring tone, such as red-black and light-black. There is a drawback. On the other hand, in the case of the latter multicolor thermosensitive recording paper, the combination of color tones can be freely selected, but when coloring at high temperatures, high aliphatic alcohols, polyethers, Polyethylene glycol derivatives, acetamide as a nitrogen-containing organic compound, stearamide, phthalonitrile, guanidine derivative as an amine derivative, etc. have been proposed, but in the conventional configuration, when coloring at high temperature, not only a low-temperature coloring layer is used. However, there was a drawback that the high-temperature color forming layer also had a decoloring effect and became unclear.

Furthermore, most two-color thermal paper has color combinations such as (blue-red) and (green-red), and no combination of (black-red) has been proposed.

〔the purpose〕

An object of the present invention is to provide a leuco-based two-color heat-sensitive recording material that has improved color separation properties and does not cause color mixture in high-temperature colored images.

(4η composition) That is, according to the present invention, three layers are laminated in this order: a support, at least a high-temperature coloring layer, and 11 an intermediate layer containing a coloring agent and a low-temperature coloring layer. The high-temperature coloring layer contains a leuco dye and a phenolic compound, and has an intermediate J? '7
contains a decolorizing agent represented by the following general formula (A), and the low-temperature coloring layer contains a leuco dye and a thiourea derivative represented by the following general formula (11). A fee will be provided.

-I injection; 1(A): General formula (B): (wherein, R1 and R2 represent hydrogen, halogen, 1-methyl group, or an alkyl group having 1 to 4 carbon atoms) In the present invention, The above general formula (A) used as a decolorizing agent
Specific examples of the compound represented by the formula include the following.

Further, as specific examples of the thiA urea derivative represented by the general formula (B) as a color developer, for example, N,N'-diphenylthiourea, III-p-ethylphenyl-N
'-phenylthiourea M, N-p-butylphenyl-N'-phenylthiourea, N,N'-cym-chlorophenylthiourea, N,N'-p-cumerolophenylthiourea, N,N' -G■-Trifluoro I"
Examples include methylphenylthiourea, N,N'-dimethylphenylthiourea, and the like.

On the other hand, examples of the color developer to be contained in the high-temperature coloring layer include 4-hydroxyphenoxide, 4-t-butylphenol, 4-hydroxyacetophenone, resolushi, α-naphthol, thymol, β-naphthol, catechol, and hydroquinone. , pyrogallol, phloroglucin,
Phloroglucincarboxylic acid, 4,4'-5ee-butylidene diphenol, 4,4'-inpropylidene-
Bis(2-butylphenol), 4-octylcatechol, 4'-5ee-butylidene diphenol,
2,2'-dihydroxydiphenyl, 2,2'-methylene-bis(4-methyl-t-butylphenol)
, 2,2-bis(4'-oxyphenyl)propane (
Also known as bisphenol A), 3,5-xylenol, etc.

The leuco dyes used in the present invention can be applied singly or in combination of two or more types, but leuco dyes such as
Any dye that has been applied to this type of heat-sensitive material may be used. For example, 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 below.

3.3-bis(p-dimethylaminophenyl)-phthalide, 3,:3-bis(p-dimethylaminophenyl)-6-
Dimethylaminophthalide (also known as Crystal Biotes 1)
-lactone), 3,;3-bis(p-dimethylaminophenyldibutylaminophenyl), :Momme,3-bis(11-dimethylaminophenyl)-6
-Chlorphthalide, :+, :+-bis(1)-dibutylaminophenyl)phthalide, :)-cyclohexylamino-6-chlorofluorane.

3-dimethylamino-5,7-dimethylfluorane, 3
-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6
-Methyl-7-chlorofluorane, 3-(N-p-1~ly-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-acorinonfluorane, 2-(N-(3'-1~lifluoromethylphenyl)amino)-6-dinithylaminofluorane, 2-(
3,6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam), 3-diethylamino-6-methyl-7-(ml~lichloromethylanilino)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)fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylospirane, 6'-bromo-3'-methoxy-benzoindolino-
Pyrylospiran, +3-(2'-hydroxy-47-dimethylaminophenyl)-:3-(2'-me1-xy5'-chlorphenyl)phthalide, 3-(2'-hydroxy-4'-dimethylaminophenyl) )-3-(2'-Me1-xy5'-21-lophenyl)phthari 1, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5' -methylphenyl)phthalide, 3-(2'-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-benzyl-1-lifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-ρ-glolphenyl)methylaminofluorane, 3-diethylamino-5-chloro-7-(α-phenylethylamino) Fluoran, 3-(N-ethyl-P-1-luidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methyl-xycarbonylphenylamino)fluoran, 3-diethylamino- 5-methyl-7-(α-phenylethylamino)fluorane, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyl 1-luidino)7-(p-r
l-butylanilino)fluorane, 3-(N-benzyl-N-cyclohexylamino)-5
, 6-penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
7.5/-benzofluorane etc.

In the present invention, in order to bind and support the leuco dye and color developer on the support, various conventional binders can be used as appropriate, such as polyvinyl alcohol,
Starch and its derivatives, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide/
Acrylic ester copolymer, acrylic amide/acrylic ester/methacrylic acid ternary copolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/
In addition to water-soluble polymers such as maleic anhydride copolymer alkali salts, polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymer, polyacrylic acid, polyacrylic acid ester, and chloride Vinyl/vinyl acetate copolymer, polybutyl methacrylate, ethylene/vinyl acetate copolymer,
Latexes such as styrene/butadiene/acrylic copolymers 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, thermofusible substances ( or lubricant), etc. can be used in combination. In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, hydroxide top plate 3)i, barium sulfate, clay, talc, and inorganic materials such as surface-treated calcium and silica. In addition to fine powder, urea
Organic fine powders such as polymarine resin, styrene/methacrylic acid copolymer, and polystyrene resin can be mentioned, and thermally fusible physical substances include, for example, 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, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones,
Examples include other thermofusible organic compounds having a melting point of about 50 to 200°C.

The two-color heat-sensitive recording material of the present invention can be modified in various ways. For example, in order to more completely prevent the influence of the decolorizing effect of the intermediate layer decoloring agent on the high-temperature coloring layer during high-temperature coloring, An intermediate layer such as a fusible material layer may be interposed between the high temperature color forming layer and the decoloring agent intermediate layer.

〔effect〕

The two-color thermosensitive recording material of the present invention has the above-mentioned structure, and when coloring is performed at a high temperature, the decoloring agent contained in the intermediate layer acts on the coloring reaction system of the low-temperature coloring layer to decolorize the low-temperature coloring image. It does not affect the high temperature coloring layer. Therefore, the two-color image A formed from the heat-sensitive recording material of the present invention has good color separation, and has a pγ bright low-temperature coloring image and a high-temperature coloring image.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples. In addition, all parts and percentages shown below are based on Chūdan (
It is the mouth.

Example 1 Dispersions A and [3, C were prepared by dispersing the following components using a ball mill at 24:11, respectively.

[Dispersion liquid-c]

3-(N-Ethyl-N-amylamino)-20 parts G-methyl-7-anilite fluorane (black) 10% hydroxyethyl cellulose aqueous solution 201I water 607I [Dispersion-B] 3.3'-Dichlorophenylthiourea 15 parts Calcium carbonate 511 Polyvinyl alcohol (10% water soluble?L 20n water
60II [Dispersion-〇] 3-diethylamino-7-chlor 20 parts Fluorane
(Red) 10% hydroxyethylcellulose aqueous solution 20 parts water
601! [Dispersion-1)) Bisphenol A 15 parts Stearic acid amide 1 (Jn 10% Hi 1-1" xyethyl cellulose waterffi Nl
i 5 /1 calcium carbonate], Qn water 7011 Δ10 parts of the dispersion prepared by using the above, dispersion 134
0 parts and 10 parts of water were mixed and stirred to obtain a thermosensitive color forming liquid for low temperature use. Separately, 10 parts of dispersion C, 3U parts of dispersion D, and 20 parts of water were mixed and stirred (4-1) to form a thermosensitive color forming liquid for high temperature coloring at 1:'f.

Furthermore, an intermediate layer forming liquid for forming an intermediate layer was prepared at the following ratio.

4.4'-dithiodimorpholine 25 parts 10% polyvinyl alcohol aqueous solution 1011 water 5 on
On top of RA commercially available high-quality paper, apply Lθ thermal color forming liquid for high temperature (dry application nail, 5.5 g/nr), intermediate layer forming liquid (
Dry coating amount 2-5 g/or), low temperature thermosensitive color forming liquid (i:ig fJ4 coating nail 1.0 g/T
rr) and then apply the two-color heat-sensitive recording material of the present invention to t! '7.

Example 2 A two-color heat-sensitive recording material of the present invention was prepared in the same manner as in Example 1 except that 3,3'-dichlorophenylthiourea in the dispersion of Example 1 was replaced with 3,3'-dichlorophenylthiourea. Obtained.

Comparative Example 1 Comparative two-color thermographic f7+ material 11) was prepared in the same manner as in Example 1 except that 3,3'-dichlorophenylthiourea in dispersion B of Example (2) was replaced with bisphenol A.

Comparative Example 2 A comparative two-color thermosensitive recording material was obtained in the same manner as in Example 1, except that 4,4'-dithiodimorpholine in the intermediate layer forming liquid of Example 1 was replaced with distearylamine.

The two-color thermosensitive recording paper obtained as described above was measured using an inclinometer with a built-in thermal head (manufactured by Tojiki 11-ki Co., Ltd.) at a head temperature of 70 to 1.50°C, a crimping time of 1 s, and a crimping pressure of 2. kg
/ cm to test the color tone, color separation properties, etc. of low-temperature and high-temperature colored images. As a result of the test, 11 ratios, 1 example,
No. 2 is a defective QY in which the high-temperature light color 11,1 low-temperature color image does not disappear and the color tone is mixed. It was a clear image.

On the other hand, the Zamboles of Examples 1 and 2 had a low 11
It was a two-color f9 model with good color separation and 'lfC properties.

Claims (1)

[Claims] (1) At least three layers are laminated in this order on a support: a high-temperature coloring layer, an intermediate layer containing a decolorizing agent, and a low-temperature coloring layer, and the high-temperature coloring layer contains a leuco dye and a phenolic compound. The intermediate layer contains a decolorizing agent represented by the following general formula (A), and the low-temperature first coloring layer contains a leuco dye and a thiourea derivative represented by the following general formula ([3)]. Two-color thermal recording monthly fee. General formula (A) d General formula (B):