JPS6354281A - Multicolor thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a multicolor image superior in color separating properties, by a method wherein, in a multicolor thermal recording material having two or more laminated thermal color forming layers coloring to different tones and containing a decoloring agent, a compound having two ester groups and two amide groups in a molecule is used as the decoloring agent. CONSTITUTION:In a multicolor thermal recording material having two or more thermal color forming layers coloring to different tones and having intermediate layers between the respective thermal color forming layers for separating decoloring layers from adjacent layers, a compound shown by formula I or II (where R1 represents alkyl or aryl, R2 represents alkyl, cycloalkyl, or aryl, and R3 represents a divalent hydrocarbon radical) is contained as a decoloring agent in at least one of respective layers. In this manner, the multicolor thermal recording material superior in color separating properties and free from color mixture can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a multicolor heat-sensitive recording material, and more particularly to a multicolor heat-sensitive recording material formed by laminating a plurality of heat-sensitive coloring layers having different color tones.

[Prior Art] A thermosensitive recording material is a material in which a thermosensitive coloring layer that forms 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. It is being

These conventional heat-sensitive recording materials include a colorless or light-colored leuco dye (color-forming main agent) having a lactone ring, lactam ring, spiropyran ring, etc. in the heat-sensitive coloring layer, and a color developer that develops color by reacting with this leuco dye when heated. Agent (coloring aid)
Those containing these are widely used because they have clear color tones and less fogging.

By the way, heat-sensitive recording materials can easily produce colored images just by heating them, so they are not only used for copying books and documents, but also used in various fields such as computer, facsimile, telex, and other fields for recording various types of information and measuring equipment. However, depending on the purpose of recording, in order to display particularly necessary data and numbers more clearly, the coloring of that part (
It goes without saying that it is desirable to be able to record with the display color (displayed color) different from the developed color of other parts.

Recently, attempts have been made to obtain multicolor recording by utilizing differences in heating temperature or thermal energy, and various multicolor thermosensitive recording papers have been proposed accordingly. Multi-color thermosensitive recording paper is generally formed by stacking two types of high-temperature and low-temperature coloring layers that develop different tones with different coloring heat energies on a support, and can be broadly classified into the following two types: Divided into types. One of them is that when coloring the high temperature coloring layer, the color is mixed with the color tone of the low temperature coloring layer to obtain a color tone different from that of the low temperature coloring 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, the former is
Publication No. 49-4342.

Special Publication No. 49-27708, Japanese Patent Publication No. 48-86543
No. 49-65239, JP-A No. 49-65239, etc.
The latter ones are published in Japanese Patent Publication No. 50-17865, Japanese Patent Publication No. 17866, Japanese Patent Publication No. 51-29024.
Publication No. 1987-87542, Japanese Patent Publication No. 1987-87542
These are disclosed in Japanese Patent Application Laid-Open No. 18048, Japanese Patent Application Laid-open No. 53-47843, and the like.

However, in the case of the former multicolor thermosensitive recording paper,
When coloring at a high temperature, the color tones that can be concretely achieved in order to mix the color with the color tone of the low temperature coloring layer are limited to black threads where the high temperature coloring tone is strong, such as red-black, blue-black, etc. There is. 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 high temperature coloring occurs, it is necessary to provide a color erasing layer containing a color erasing agent to erase the color of the low temperature coloring layer. There is. It has been proposed to use aliphatic amines, aromatic amines, polyethers, etc. as such decolorizing agents. However, these decoloring agents have the disadvantage that they do not sufficiently decolor the coloring layer, resulting in mixed colors.

〔the purpose〕

An object of the present invention is to overcome the problems of the prior art described above, and to provide a multicolor thermosensitive recording material that has excellent color separation properties and does not cause color mixing.

〔composition〕

According to the present invention, a plurality of thermosensitive coloring layers that develop colors in different tones are laminated. structure and also contains a decoloring agent, the decolorizing agent has two ester groups and two amide groups in one molecule of the following general formula (,
A heat-sensitive recording material characterized by using a compound represented by 1) or (n) is provided.

(In the formula, R1 represents an alkyl group or an aryl group, and R3 represents an alkyl group, a cycloalkyl group, or an aryl group.) (In the formula, R1 represents an alkyl group or an aryl group, and R2 represents an alkyl group or a cycloalkyl group. , or an aryl group, R3
represents a divalent hydrocarbon group) In the present invention, a plurality of heat-sensitive coloring layers that develop colors in different tones are provided on a support, and if necessary, a decoloring layer and an adjacent layer are separated between each heat-sensitive coloring layer. In the multicolor heat-sensitive recording material provided with an intermediate layer for
Since the compound represented by I) is contained, it is possible to obtain a multicolor heat-sensitive recording material that has excellent color separation properties and does not cause color mixture.

The compound of general formula (1) or (II) used in the present invention is usually a white powder that is poorly soluble in water and can be used as a decolorizing agent, but it can be used in combination with other commonly used decolorizing agents. It is also possible. The amount used can be selected as appropriate, but it ranges from 1.0g/rf to 5.0g/rf. Og/% is appropriate.

Specific examples of the compound of general formula (1) include the compounds shown below.

N, N'-bis(methylsuccinyl)piperazine, N,
N'-bis(ethylsuccinyl)piperazine, N,N'
-bis(methyladipoyl)piperazine.

N,N'-bis(ethyladipoyl)piperazine.

N,N'-bis(methylsevacoyl)piperazine, N,
N'-bis(ethyl sebacoyl)piperazine, N,N'
-bis(methylisophthaloyl)piperazine, N, N'
-bis(ethyl isophthaloyl)piperazine, N, N'
-Bis(methylterephthaloyl)piperazine.

N,N'-bis(ethylterephthaloyl)piperazine,
N, N'-bis(methylphthaloyl)piperazine, N,
Specific examples of N'-bis(ethyl phthaloyl)piperazine and the compound represented by general formula (II) include the compounds shown below.

1.3-bis(4(N-methylsuccinylpiperidyl)
) propane, 1,3-bis(4(N-ethylsuccinylpiperidyl)
)propane.

1.3-bis(4(N-methylglutarylpiperidyl)
) propane, -1,3-bis(4(N-ethylglutarylpiperidyl))propane, 1,3-bis(4(N-methyladipoylpiperidyl))
) propane, 1,3-bis(4(N-ethyladipoylpiperidyl)
) propane, 1,3-bis(4(N-methylsebacoylpiperidyl)
) propane, 1,3-bis(4(N-ethylsebacoylpiperidyl)
) propane, 1,3-bis(4(N-methylisophthylpiperidyl))propane.

1.3-bis(4(N-ethyl isophthylpiperidyl))propane.

1.3-bis(4(N-methylterephthylpiperidyl))propane, 1.3-bis(4(N-ethylterephthylpiperidyl))propane In the present invention, the leuco dye used in the heat-sensitive coloring layer may be used alone or in combination with two These leuco dyes can be applied in a mixture of more than one species, and any of the leuco dyes that have been applied to this type of heat-sensitive material can be used, such as triphenylmethane, fluoran, phenothiazine, auramine, etc. Leuco compounds of dyes such as , spiropyran, and indolinophthalide 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 crystalno(iolet lactone), 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide) (p-dimethylaminophenyl)-6-dimethylaminophenyl, 3.3-bis(P-dimethylaminophenyl)-6-chlorophthalide, 3.3-bis(ρ-dibutylaminophenyl) phthalide.

3-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-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane.

2- (N-(3'-trifluoromethylphenyl)
amino)-6-dinithylaminofluorane.

2-(3,6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam), 3-diethylamino-6-methyl-7-chloromethylanilino)fluoran.

3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(0-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-81-methoxy-benzoindolino-pyrylosvirane, 6'-bromo-3'-methoxy-benzoindolino-pyrylospirane.

3-(2'-Hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-57-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-51
-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluoran.

3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluorane, 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-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluoranylethylamino)fluoran, 3 -diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-〇-butylanilino)fluoran, 3-(N-benzyl-N-cyclohexylamino)-5
, 6-penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
',5'-benzofluorane etc.

In the present invention, the color developer that reacts with the leuco dye to develop color when heated is a color developer.

Various electron-accepting substances are applied, including phenolic substances,
Examples include organic or inorganic acidic substances, metal salts thereof, aromatic amide compounds, aromatic urea compounds, etc., and specific examples thereof are shown below.

Clay, activated clay, activated silica, boric acid, zinc oxide, zinc chloride, aluminum chloride, 4,4'-isopropylidene bisphenol, 4,4'-isopropylidene bis-(0-cresol), 4,4'-isopropy Redenbis (o-tart-butylphenol), 4.
4'-isopropylidene-bis(0-chlorophenol), 4.4'-cyclohexylidenebisphenol, 4,4'-bisphenolsulfone, 4-hydroxy-4'-chloro-diphenylsulfone, 4-hydroxy-4' -isopropoxydiphenylsulfone, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate, salicylic acid anilide, salicylic acid (0-chloroanilide), salicylic acid (n-trifluoromethyl) anilide), dimethyl 4-hydroxyphthalate, 2-hydroxy-3-naphthoic acid, benzyl 2-hydroxy-3-naphthoate, zinc droxy-3-naphthoate, zinc chloride/antipyrine complex, methylenebis-(oxyethylenethio) Diphenol, 4-hydroxyacetophenone, novolak type phenol resin, novolak type phenylphenol resin, diphenylthiourea, di(grave-chlorophenyl)thiourea, di(m-trifluoromethylphenyl)thiourea, 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.5For example, polyvinyl alcohol, starch and its derivatives, methoxy cellulose, hydroxy 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 ester, vinyl chloride/vinyl acetate copolymer, and Latexes such as butyl 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, 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, zinc hydroxide, barium sulfate, clay, talc, and surface-treated inorganic fine powders such as calcium and silica. , urea-formalin resin, styrene/methacrylic acid copolymer, polystyrene resin, and other organic fine powders. Examples of thermofusible substances include higher fatty acids or their esters, amides, or metal salts. In addition, various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, and other thermofusible organics. Examples include compounds having a melting point of about 50 to 200°C.

For example, in order to obtain a two-color heat-sensitive recording material according to the present invention, a liquid in which a color-developing dye, a color developer, a decolorizing agent, a binder, etc. are dispersed or dissolved on a support such as paper, synthetic paper, or plastic film is used. It can be obtained by applying it, drying it, and repeating it. When further laminating on top of the coated layer, it is necessary to pay close attention to the solubility and releasability of the layer so that the lower layer does not mix with the upper layer. Further, after coating and drying, the upper layer may be coated after xarender treatment.The amount of dye attached to the high temperature coloring layer is 0.3g/rrr to 1.0g/rrr. Og/rrr,
The amount of decolorizing agent attached to the decolorizing agent layer is 1.0g/rrr~Log
/rrr, and the amount of the low-temperature coloring layer deposited is as described above.

Leuco dye adhesion as dry matter: 0.2g/rrr~
It is 0.5g/rf. When providing a protective layer, the amount of adhesion is preferably 0.5 g/nf to 5.0 g/rd. If provided, the former is 0.5 g/-~5
．． 0 g/- is preferable, and the latter is 1゛g/rrr~1
0 g/bo is preferable.

Furthermore, by further increasing the number of thermosensitive coloring layers in the same manner as described above, it is also possible to obtain a multicolor thermosensitive recording material having three or more colors.

〔effect〕

The multicolor heat-sensitive recording material of the present invention has the above-mentioned structure, and uses the compound of the general formula (1) or (II) as a decoloring agent to clearly express a plurality of color tones without mixing colors. It can produce multicolor images with excellent brown color separation.

〔Example〕

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.

Examples 1 to 4 Dispersions A to F were obtained by grinding and dispersing the following components using a sand grinder to give a volume average particle size of 2 to 3 μm.
I got it.

(Dispersion-A) 3-(N-Ethyl-N-amylamino)-6-20 parts methyl-7-anilite fluorane (black) 10% hydroxyethylcellulose aqueous solution 2011 water
60 parts [dispersion liquid-
B] 3.3'-dichlorophenylthiourea 10 parts N-
Stearylbenzamide 101 Calcium carbonate 10 #Polyvinyl alcohol 10% aqueous solution 20 Water
50 [Dispersion-C] 3-diethylamino-7-chlorofur 20 parts Orane (red) 10% hydroxyethylcellulose aqueous solution 20# water
60
[Dispersion-D] 3.3'-Dichlorophenylthiourea 10 parts Calcium carbonate 10 10% polyvinyl alcohol aqueous solution 20 Water
60 [Dispersion-F] Crystal violet lactone (blue) 20 parts 1
0% hydroxyethyl cellulose aqueous solution 20n water
60
Part [Dispersion-F] Bisphenol A 10 parts Calcium carbonate loIFlo% hydroxyethyl cellulose aqueous solution 15 Water
65〃10 parts of dispersion A prepared as above, 870 parts of dispersion,
20 parts of water were each taken and mixed and stirred to obtain a thermosensitive color forming liquid for low temperature use. On the other hand, 10 parts of Dispersion C, 70 parts of Dispersion D, and 20 parts of water were each taken and mixed and stirred to obtain a thermosensitive coloring layer forming liquid for medium temperature coloring.

Further, 1 part of the dispersion EIO, 2 parts of the dispersion F2O, and 20 parts of water were each taken and mixed and stirred to obtain a thermosensitive coloring layer forming liquid for high temperature coloring. Further, a decolorizing agent layer forming liquid for forming a decolorizing agent layer was prepared at the following ratio.

[Decolorizer layer forming liquid]

Decoloring agent in Table-1 20 parts 10
% polyvinyl alcohol aqueous solution 20〃water
60〃
Next, on a commercially available high-quality paper with a basis weight of about 52 g/rrr, the high temperature thermosensitive coloring layer forming liquid (dry coating amount 5 g/rf), the decoloring agent layer forming liquid (dry coating amount 3 g/rrr), Terpene resin latex (solid content 40%) (
(Dry coating amount: 3 g/nf), Medium temperature thermosensitive coloring layer forming liquid (Dry coating amount: 4.5 g/rd), Decoloring agent layer forming liquid (Dry coating amount: 3 g/n?), Terpene as intermediate layer forming liquid Resin latex (solid content 4%) (dry application amount 3g/if)
.

A low-temperature thermosensitive coloring layer forming liquid (dry coating amount: 4 g/1rr) was applied and dried in sequence, and then the smoothness was 500 to 1000 seconds.
Examples 1 to 1 of the present invention were calendered so that
A multicolor heat-sensitive recording material No. 4 was prepared.

Comparative Example In Example 1, N,N'-bis(
N, N' instead of methylterephthaloylpiperazine)
, Example 1 except that N"-triphenylguanidine was used.
A heat-sensitive recording material for comparison was prepared in the same manner as described above.

Table 1 The multicolor thermosensitive recording materials of Examples and Comparative Examples obtained as described above were tested for dynamic coloring characteristics using a G-m facsimile test machine.

The test machine was an 8 dot 1 liter manufactured by Matsushita Electronic Components Co., Ltd.
111 thermal head, heating element resistance is approximately 400Ω
/dot and 1 color development test is performed at a main scanning recording speed of 20
m5ec/1ine, sub-scanning 3.85 Q/a
m, platen suppression 3.0kg/aJ, head input 0.6
The test was conducted under the condition of 1/dot. The coloring energy is 1 for the low temperature coloring layer, OmJ, and 2.0m for the medium temperature coloring layer. The test was carried out at OtmJ and a high temperature coloring layer of 3.3 mJ.

In addition, a Macbeth densitometer was used to measure the concentration.

As a result of the test, in Examples 1 to 4, the three constituent colors were clearly separated and developed, whereas in the comparative example, the three constituent colors exhibited a mixed color.

As described above, it can be seen that the color separation properties of the multicolor thermosensitive recording material of the present invention are significantly improved.

Claims (1)

[Claims] (1) In a multicolor thermosensitive recording material that has a structure in which a plurality of thermosensitive coloring layers that develop colors in different tones are laminated and also contains a decoloring agent, the decolorizing agent contains two ester groups and two amide groups in one molecule. The following general formula (I) or (II) having a group
) A heat-sensitive recording material characterized by using a compound represented by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 is an alkyl group or an aryl group, R_2
represents an alkyl group, a cycloalkyl group, or an aryl group. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (In the formula, R_1 is an alkyl group or an aryl group, R_2 is
is an alkyl group, a cycloalkyl group, or an aryl group,
R_3 represents a divalent hydrocarbon group. )