JP3286664B2 - Thermal recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, and more particularly to a heat-sensitive recording material having excellent storage stability of recorded images.

[0002]

2. Description of the Related Art In general, there are various recording materials utilizing a color development reaction by heat, pressure or the like between a colorless or pale color electron-donating dye (leuco dye) and a developer which forms a color when the dye is contacted. Proposed. One such thermal recording material is
Published in Japanese Patent Publication No. 43-4160, Japanese Patent Publication No. 45-14039, Japanese Patent Application Laid-Open No. 48-27736, etc., it is not necessary to perform complicated processing such as development and fixing, and a relatively simple apparatus can be used for a short time. It is widely used as various recording materials for electronic computers, facsimile machines, ticket vending machines, label printers, recorders, and the like because of its advantages such as low noise and low noise.

As a color-forming dye used in a heat-sensitive recording material, for example, a colorless or light-colored leuco dye having a lactone, lactam or spiropyran ring is used. Have been. The heat-sensitive recording material using this leuco dye and a developer,
It is widely used because of its high image density and high whiteness of the background. On the other hand, in recent years, as the demand for the thermal recording method has increased, the demand for improving the storage properties of the recorded image with respect to chemicals, light, heat, and the like has been increasing, and the development of a recording material that can respond to this has been strongly desired. ing.

[0004]

In order to cope with high storage stability of recorded images, high-reliability developers such as those disclosed in JP-A-58-82788 and JP-A-60-13852 are disclosed.
Phenol sulfone compound is disclosed in
No. 47292 discloses a metal salt of benzoic acid.
Substituted salicylic acid compounds have been proposed in JP-B-169681, but heat-sensitive recording materials using these compounds as a color developer are still insufficient in terms of fastness to oils and fats, plasticizers, water and the like in the image area. Hard to say. Further, many of the developers having improved reliability as described above generally have a high acidity. When an inorganic filler such as calcium carbonate is used in combination with the developer, carbon dioxide gas is generated, and the liquid of the coating liquid is generated. However, there is a problem that the coloring property is deteriorated and the coloring ability of the coloring agent itself is also reduced.

On the other hand, it has been proposed to provide various intermediate layers as means for improving recording sensitivity, and a method using various inorganic pigments, a method using non-expandable hollow particles for the intermediate layer, and the like have been proposed. However, these proposed recording materials have disadvantages such as insufficient color sensitivity and poor recording characteristics.

Accordingly, the present invention has been made in view of the above-mentioned circumstances of the prior art, and has excellent storage stability due to high oil resistance and plasticizer resistance of a recorded image, and further has a high degree of stability suitable for a high-speed recording material. It is an object of the present invention to provide a heat-sensitive recording material having high sensitivity.

[0007]

According to the present invention, there is provided a heat-sensitive recording material having a leuco dye and a heat-sensitive coloring layer as a color developer for developing the leuco dye upon heating.
It is characterized in that at least one phthalic acid derivative represented by the following general formula (I) is used as the color developer, and that at least one selected from silicon dioxide, aluminum hydroxide, clay, talc and kaolin is used as an inorganic filler. Is provided.

Embedded image

Further, according to the present invention, an intermediate layer mainly composed of fine plastic spherical hollow particles made of a thermoplastic resin is provided between the support and the thermosensitive coloring layer. A recording material is provided.

The heat-sensitive recording material of the present invention uses at least one phthalic acid derivative represented by the general formula (I) as a color developer, so that the stability of recorded images is excellent. By using at least one selected from aluminum hydroxide, clay, talc, and kaolin, the head matching property when printing with a thermal head or the like becomes excellent. The inorganic filler used in the present invention may be contained in the thermosensitive coloring layer or in a protective layer formed on the thermosensitive coloring layer.

Further, the recording material of the present invention is provided with an intermediate layer mainly composed of plastic spherical hollow particles between a support and the thermosensitive coloring layer, so that the recording material is excellent in heat sensitivity and suitable for high-speed recording. Become.

Specific examples of the compound represented by the general formula (I) used in the present invention include those shown in the following Table 1, but the present invention is not limited thereto.

[0012]

[Table 1- (1)]

[0013]

[Table 1- (2)]

[0014]

[Table 1- (3)]

[0015]

[Table 1- (4)]

In the present invention, the leuco dye used in the thermosensitive coloring layer is used alone or in combination of two or more.
As such a leuco dye, those applied to this kind of heat-sensitive material are arbitrarily applied, and for example, triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, indolinophthalide-based and the like A leuco compound of a dye is 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-dimethylaminophenyl)
-6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-
Dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-5,
7-dimethylfluoran, 3-N-methyl-N-isobutyl-6-
Methyl-7-anilinofluoran, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino-7,8-benzfluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3- (N-p-tolyl-N-ethylamino) -6-
Methyl-7-anilinofluoran, 3-pyrrolidino-6-
Methyl-7-anilinofluoran, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluoran, 2- {3,6-bis (diethylamino) -9- (o-
(Chloranilino) xanthylbenzoate 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-diethylamino-6-methyl-7- (2 ', 4'-dimethylanilino ) Fluoran, 3- (N, N-diethylamino) -5
-Methyl-7- (N, N-dibenzylamino) fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-
3'-methoxy-benzoindolino-spiropyran, 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
-Morpholino-7- (N-propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-trifluoromethylanilinofluoran, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethyl (Anilino) 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-piperidinofluoran, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluoran, 3-
(N-methyl-N-isopropylamino) -6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3,6-bis (dimethylamino) fluorenespiro ( 9,3 ′)-6′-dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α
-Naphthylamino-4'-bromofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-N-ethyl-N
-(2-ethoxypropyl) amino-6-methyl-7-anilinofluoran, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluoran, 3-diethylamino
-6-methyl-7-mesitidino-4 ', 5'-benzofluoran, 3-
(p-dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p-dimethylaminophenyl) -3- {1,1-bis ( p-dimethylaminophenyl) ethylene-2-yl} -6-dimethylaminophthalide,
3- (p-dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-phenylethylene-2-yl) phthalide, 3- (p-
Dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-p-chlorophenylethylene-2-yl) -6-dimethylaminophthalide, 3- (4'-dimethylamino-2'-methoxy)-
3- (1 ''-p-dimethylaminophenyl-1 ''-p-chlorophenyl-1 '', 3 ''-butadiene-4 ''-yl) benzophthalide, 3-
(4'-Dimethylamino-2'-benzyloxy) -3- (1 ''-p-dimethylaminophenyl-1 ''-phenyl-1 '', 3 ''-butadiene-4 ''-yl) benzophthalide , 3-dimethylamino-6-dimethylamino-fluorene-9-spiro 3 ′ (6′-dimethylamino) phthalide, 3,3-bis {2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ) Ethenyl} -4,5,6,7-tetrachlorophthalide, 3-bis {1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl} -5,6-dichloro-4,7- Dibromophthalide, bis (p-dimethylaminostyryl) -1-naphthalenesulfonylmethane, bis (p-dimethylaminostyryl) -1
-p-tolylsulfonylmethane and the like.

Examples of the color developing agent used in the thermosensitive coloring layer of the present invention include various electron-accepting compounds capable of coloring the leuco dye upon contact, such as phenolic compounds, thiophenolic compounds, thiourea derivatives, and organic compounds. Acids and metal salts thereof are preferably applied, and specific examples thereof include the following.

4,4'-isopropylidenebisphenol,
4,4′-isopropylidenebis (o-methylphenol),
4,4′-secondary butylidenebisphenol 4,4′-isopropylidenebis (2-tert-butylphenol), 4,4′-cyclohexylidenediphenol,
4,4′-isopropylidenebis (2-chlorophenol),
2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis
(6-tert-butyl-2-methylphenol), 1,1,3
-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4'-thiobis ( 6-tert-butyl-2-methylphenol),
4,4′-diphenolsulfone, 4-isopropoxy-4′-hydroxydiphenylsulfone, 4-benzyloxy-4′-hydroxydiphenylsulfone, 4,4′-diphenolsulfoxide, isopropyl P-hydroxybenzoate, P -Benzyl hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,
5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -propane, 1,3-bis (4-hydroxyphenylthio ) -2-Hydroxypropane, N, N′-diphenylthiourea, N, N′-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, 2-hydroxy-3-naphthoic acid, 2 -Hydroxy-1
-Naphthoic acid, 1-hydroxy-2-naphthoic acid, metal salts of hydroxynaphthoic acid such as zinc, aluminum and calcium, bis- (4-hydroxyphenyl) acetic acid methyl ester, bis- (4-hydroxyphenyl) acetic acid benzyl ester , 1,3-bis (4-hydroxycumyl) benzene, 1,4
-Bis (4-hydroxycumyl) benzene, 2,4'-diphenolsulfone, 3,3'-diallyl-4,4'-diphenolsulfone, α, α-bis (4-hydroxyphenyl) -α- Methyltoluene, antipyrine complex of zinc thiocyanate,
Tetrabromobisphenol A, tetrabromobisphenol S, 4,4'-thiobis (2-methylphenol), 4,4'-
Thiobis (2-chlorophenol) and the like.

In order to obtain the heat-sensitive recording material of the present invention, a heat-sensitive coloring layer containing a leuco dye, a color developer, an inorganic filler and an auxiliary component described below may be provided on a support. When the intermediate layer is provided, the above-described thermosensitive coloring layer may be provided on the intermediate layer after the intermediate layer is formed by binding and supporting the plastic spherical hollow particles on the support. In this case, as the binder used for forming the heat-sensitive coloring layer and the intermediate layer, various conventional binders can be appropriately used. To give such binders and specific examples, for example,
The following are mentioned.

Polyvinyl alcohol, starch and derivatives thereof, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, cellulose derivatives such as methyl cellulose, ethyl cellulose, etc .; -Da, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene /
Maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein and other water-soluble polymers, polyvinyl acetate, polyurethane, polyacrylic acid, Polyacrylate, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene /
Emulsions such as vinyl acetate copolymers and latexes such as styrene / butadiene copolymers and styrene / butadiene / acrylic copolymers.

In the present invention, various heat-fusible substances can be used as a sensitivity improver, and specific examples thereof include the following, but are not limited thereto. . Fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, fatty acid metal salts such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate and zinc behenate, p-benzyl Biphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, phenyl β-naphthoate, phenyl 1-hydroxy-2-naphthoate, methyl 1-hydroxy-2-naphthoate, diphenyl Carbonate, gliacol carbonate, dibensil terephthalate, dimethyl terephthalate, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1,2-diphenoxyethane, 1,2 -
Bis (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-diphenoxy-2-butene, 1,2-
Bis (4-methoxyphenylthio) ethane, dibenzoylmethane, 1,4-diphenylthiobutane, 1,4-diphenylthio
2-butene, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- (2
-Vinyloxyethoxy) bifer, p-aryloxyphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, dibenzoyloxypropane, dibenzyldisulfide, 1,1-diphenylethanol, 1,1-diphenylpropanol, p -Benzyloxybenzyl alcohol, 1,3-phenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-
Octadecylcarbamoylbenzene, 1,2-bis (4-methoxyphenoxy) propane, 1,5-bis (4-methoxyphenoxy) -3-oxapentane, dibenzyl oxalate, bis (4-methylbenzyl) oxalate, oxalic acid Bis (4-chlorobenzyl) and the like.

When a heat-sensitive recording material is to be obtained, if necessary, additional components commonly used in this type of heat-sensitive recording material, such as a filler, a surfactant, a lubricant, and a pressure coloring inhibitor, can be used in combination. . In this case, examples of the filler include organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and vinylidene chloride resin, and examples of the lubricant include higher fatty acids and metal salts thereof. , Higher fatty acid amides, higher fatty acid esters,
Examples include animal, vegetable, mineral or petroleum waxes.

[0024]

Next, the present invention will be described in more detail with reference to examples. The following parts and percentages are all based on weight.

Example 1 A mixture having the following composition was separately dispersed in a glass mayonnaise bottle using a glass ball in a ball mill for 2 days to prepare [Solution A], [Solution B] and [Solution C]. did. [Solution A] 3-N, N-dibutylamino-6-methyl-7-anilinofluoran 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [Solution B] 4- (β-phenoxyethoxy) phthalic acid 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [Solution C] Aluminum hydroxide 20 parts Water 80 parts

Next, 10 parts of [solution A], 30 parts of [solution B]
[Liquid C] 20 parts and zinc stearate dispersion (concentration 3
(0%) 10 parts were mixed to obtain a thermosensitive coloring layer forming liquid. This liquid for forming a heat-sensitive color-forming layer was prepared using commercially available high-quality paper (basis weight: 52 g / m ² ).
Was coated and dried so that the amount of dye attached after drying was 0.5 g / m ² to form a thermosensitive coloring layer. Thereafter, the surface of the layer was calendered so that the surface smoothness became 500 to 600 seconds to prepare a heat-sensitive recording material.

Example 2 A heat-sensitive recording material was prepared in the same manner as in Example 1 except that the following [Liquid D] was used in place of [Liquid B]. [Solution D] 4- (4'-phenoxybutoxy) phthalic acid 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts

Example 3 The following mixture was stirred and dispersed to obtain an intermediate layer forming liquid [Solution E]. [E Solution] Aqueous solution in which minute hollow particles are dispersed (copolymer resin mainly composed of vinylidene chloride and acryl 30 parts nitrile, solid content concentration 32%, average particle diameter 5 μm, hollow ratio 90%) Styrene / butadiene copolymer Latex 20 parts (solid content 47.5%) Water 60 parts

The above-mentioned intermediate layer forming liquid was applied to the surface of a commercially available high-quality paper (basis weight: 52 g / m ² ) and dried and weighed to 5 g / m ² to form an intermediate layer. Next, the thermosensitive coloring layer-forming solution prepared in Example 1 was applied and dried on the intermediate layer so that the amount of dye applied after drying was 0.5 g / m ² to provide a thermosensitive coloring layer. The layer surface was calendered so that the surface smoothness was 500 to 600 seconds to prepare the heat-sensitive recording material of the present invention.

Comparative Example 1 A heat-sensitive recording material was prepared in the same manner as in Example 1 except that the following [Solution F] was used instead of [Solution C]. [Solution F] Calcium carbonate 20 parts Water 80 parts

Comparative Example 2 A heat-sensitive recording material was prepared in the same manner as in Example 3, except that the liquid for forming a thermosensitive coloring layer was changed from that prepared in Example 1 to that prepared in Comparative Example 1. .

Comparative Example 3 A heat-sensitive recording material was prepared in the same manner as in Example 1, except that the following [Solution G] was used instead of the [Solution B]. [Solution G] 4-hydroxy-4'-isopropoxydiphenylsulfone 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts

The thus obtained heat-sensitive recording material was printed with a printing device manufactured by Matsushita Electronic Components under the conditions of an applied power of 0.68 w / dot and a line cycle of 10 ms / Line. The color density and the background density are measured using a Macbeth densitometer RD-
At 914, the concentration was measured. Table 1 shows the results.

[Table 1]

Next, the heat-sensitive recording material was printed in a heat block at 150 ° C. under the conditions of ² kg / cm ² and 1 second, and each printed sample was tested for water resistance, oil resistance and plasticizer resistance. Table 2 shows the results. The test conditions are as follows, and the measurement of the coloring density and the background density is the same as described above. Water resistance test Concentration of background and coloring area after test sample is submerged in tap water for 16 hours Oil resistance test After applying cottonseed oil (Kanto Chemical Reagent) to the test sample surface, store at 40 ° C dry condition for 16 hours Concentration of the background and the color-developed part after the test Plasticizer resistance test After stacking three PVC wrap films (made by Shin-Etsu Polymer) on the surface of the test sample, applying a load of 5 kg, and storing for 16 hours at 40 ° C. under dry conditions Density of background and colored areas

[Table 2]

[0035]

The heat-sensitive recording material of the present invention has excellent coloring sensitivity and recording density, as well as excellent water resistance and oil resistance.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-316096 (JP, A) JP-A-6-321859 (JP, A) JP-A-6-329586 (JP, A) JP-A-5-329586 85058 (JP, A) JP-A-5-286251 (JP, A) JP-A-5-112079 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/28-5 / 34 CAPLUS (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A thermosensitive recording material having on a support a thermosensitive coloring layer mainly composed of a leuco dye and a color developing agent for coloring the leuco dye when heated, wherein the color developing agent is represented by the following general formula (I): A heat-sensitive recording material characterized by using at least one phthalic acid derivative represented by the formula (I) and further comprising at least one selected from silicon dioxide, aluminum hydroxide, clay, talc and kaolin as an inorganic filler. Embedded image 2. Between the support and the thermosensitive coloring layer,
2. An intermediate layer comprising, as a main component, spherical plastic hollow particles made of a thermoplastic resin.
2. The heat-sensitive recording material according to item 1.