JP3465806B2 - 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 heat-sensitive recording paper and a heat-sensitive recording material used in a serial printing type word processor thermal printer or the like.

[0002]

2. Description of the Related Art A heat-sensitive recording material comprises a support and a heat-sensitive coloring layer containing an electron-donating colorless or light-colored dye precursor and an electron-accepting developer as main components. By heating with a hot pen, laser light or the like, the dye precursor and the developer react instantaneously to obtain a recorded image. Such a heat-sensitive recording material has advantages that a recorded image can be obtained with a relatively simple device, maintenance is easy, and noise is reduced.
In addition to the field of printers, it is widely used as a recording material for ticket vending machines.

In particular, in recent years, the needs of word processors have been rapidly expanding from those for office equipment to those for general personal use. Such a personal word processor generally adopts a serial printing method using a serial head as a recording method. However, as with a general line head type label printer, the recording material is required to have a high density. There is. In addition, the serial print method has a larger friction between the head and the recording material than the line head method, and because of its structure, the recording is performed while the head side is moving, so a ruled line perpendicular to the head moving direction is printed. At that time, the ruled line is misaligned for each printing. That is, the head in the serial printing system has its lower end supported by the head support member and its upper end as a free end, and this head is pressed against a recording medium, for example, paper, slightly before the printing unit, and then starts. Since the printing is performed, the upper end of the head is easily displaced to the right with respect to the lower end of the head in the printing process. Such a displacement also occurs in the second printing after that, and the position of the print mark formed by the upper end of the head displaced for the second time is to the right of the position immediately below the position of the print mark formed by the lower end of the head in one print. As a result, the printing shifts, and thus the printing shift occurs. In particular, in the case of vertical ruled line printing, printing deviation is more clearly recognized because printing of the second upper part starts from a position adjacent to the end point position of the first printing. This print misalignment increases as the friction between the recording material and the head increases.
Expanding.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal recording material which is improved in problems and ruled line deviations in a thermal recording apparatus using a serial printing method and which is excellent in color density and head matching. Especially.

[0005]

[Means for Solving the Problems]
Ming (1) "Main component is leuco dye and developer on support
And a pigment and resin are mainly formed on the thermosensitive coloring layer.
The heat-sensitive recording material has a protective layer that is sequentially laminated.
In the protective layerAs a pigment to be included inThickness of protective layer
More than 1.0 timesAcrylic resin with average particle size,protection
Less than 1.0 times the layer thicknessUses an inorganic pigment with an average particle size
Characterized byThermal recording material ", (2)" The protective layer
More than 1.0 times the thickness ofAcrylic resin with average particle size
Is 3 to 15% by weight of the protective layer.
Achieved by the heat-sensitive recording material described in the item (1).
To be done.

That is, according to the present invention, a thermosensitive coloring layer containing a leuco dye and a developer as main components, and a protective layer containing a pigment and a resin as main components are sequentially laminated on the support. In a thermal recording material used in a serial printing method such as a word processor thermal printer, the protective layer contains
The pigment to be used should have a flatness 1.0 times or more the thickness of the protective layer.
Provided is a heat-sensitive recording material characterized by using an acrylic resin having a uniform particle size and an inorganic pigment having an average particle size less than 1.0 times the thickness of the protective layer.

Further, according to the present invention, the heat-sensitive recording is characterized in that the acrylic resin having an average particle diameter of 1.0 times or more the thickness of the protective layer is 3 to 15% by weight of the protective layer. Material is provided.

The pigment used in the present invention is an acrylic resin having an average particle size of 1.0 times or more the thickness of the protective layer.
And an inorganic face having an average particle size of less than 1.0 times the thickness of the protective layer
It is a fee. If the average particle size is 1.0 times or more the thickness of the protective layer
Acrylic resin alone is inferior in head matching when trying to obtain a high-concentration heat-sensitive recording material, and an inorganic pigment having an average particle diameter of less than 1.0 times the thickness of the protective layer has little effect on ruled line deviation.

Still more preferably, the acrylic resin having an average particle diameter of 1.0 times or more the thickness of the protective layer is 3 to 15% by weight of the protective layer. 1.0 of the thickness of the protective layer
Acrylic resin with an average particle size more than twice the
If it is less than 10% by weight, the effect against the deviation of ruled lines is small, and if it is 15% by weight or more, the color density is low.

The pigment used in the present invention includes:
One or more of the pigments commonly used for this type of heat-sensitive recording material can be selected. As a concrete example,
Calcium carbonate, silica, kaolin, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic fine powder such as surface treated calcium and silica, and organic acrylic resin Fine powder can be mentioned.

In the present invention, an intermediate layer may be provided between the support and the thermosensitive color developing layer, if necessary. In this case, the intermediate layer may contain hollow fine particles or an inorganic pigment. Various kinds of hollow body particles are used, and examples thereof include hollow body particles formed of materials such as glass, ceramics and plastics, and hollow body particles made of a thermoplastic resin and having a hollow ratio of 10% or more are particularly preferable. . Further, as the inorganic pigment, the oiling amount is 30 ml / 100 g or more, preferably 80 ml / 100
More than g is selected. As these inorganic pigments, one or more of the pigments commonly used in this type of heat-sensitive recording material can be selected. Specific examples thereof include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate,
Examples thereof include clay, talc, and inorganic pigments such as surface-treated calcium and silica.

The leuco dyes used in the present invention may be applied alone or as a mixture of two or more kinds, and as such leuco dyes, those applied to the recording material of this kind are arbitrarily applied, for example, Phenylmethanephthalide type, triallylmethane type, fluorane type, phenothidian type, thioferolane type, xanthene type, indophthalyl type, spiropyran type, azaphthalide type, chromenopyrazole type, methine type, rhodamine anilinolactam type, rhodamine lactam type A leuco compound such as a quinone, a quinazoline, a diazaxanthene, or a bislactone is preferably used. Examples of such compounds include those shown below.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluorane, 3 -Dimethylamino-5,
7-Dimethylfluorane, 3- (N-methyl-N-isoamylamino) -6-methyl-7-anilinofluorane, 3- (N-methyl-N-isobutylamino) -6-
Methyl-7-anilinofluorane, 3- (N-ptolyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3- (N-methyl-N-amylamino) -6
-Methyl-7-anilinofluorane, 3- (N, N-di-n-amylamino) -6-methyl-7-anilinofluorane,

3- (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane, 3-
(N-methyl-N-isopropylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluorane, 3- Diethylamino-7,8-benzfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-
Diethylamino-6-methyl-7-chlorofluorane,
3-pyrrolidino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (m-trichloroanilino) fluorane, 3-diethylamino-7
-(O-chloroanilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-6-methyl-7-anilinofluorane,
3-dibutylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (2 ',
4'-dimethylanilino) fluorane,

3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluorane,
Benzoyl leuco methylene blue, 6'-chloro-8 '
-Methoxybenzoindolinospiropyran, 6'-bromo-8'-methoxybenzoindolinospiropyran, 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-propyltrifluoromethylanilino) fluorane, 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) fluorane, 3- (N-
Ethyl-N-ptoluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7-
(O-methoxycarbonylphenylethylfluorane), 3-diethylamino-5-methyl-7- (α-phenylethylamino) fluorane, 3-diethylamino-7-piperidinoaminofluorane, 2-chloro-3-
(N-Methyltoluidino) -7- (p-N-butylanilino) fluorane, 3,6-bis (dimethylamino) fluorenspiro (9,3 ′)-6′-dimethylaminophthalide, 3- (N-ethyl-) N-cyclohexylamino) -5,6-benzo-7-α-naphthylamino-4 '
-Bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3- (N-ethyl-N-2)
-Ethoxypropylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tetrafurfurylamino) -6-methyl-7-anilinofluorane,

3-Diethylamino-6-methyl-7-mesitidino-4 ', 5'-benzofluorane, 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-dimethylamino) Phenyl) -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-ptolylsulfonylmethane and the like.

Further, in the present invention, various electron-accepting compounds such as phenolic compounds are used as color developers.
A thiophenolic compound, a thiourea derivative, an organic acid and a metal salt thereof can be used, and specific examples thereof include the followings, but the present invention is not limited thereto. 4,4'-isopropylidenediphenol, 4,4'-isopropylidenebis-o-methylphenol, 4,4'-sec-butylidenebisphenol, 4,4'-isopropylidenebis (2-tert-)
Butylphenol, zinc p-nitrobenzoate, 1,3
5-tris (4-tert-butyl-3-hydroxy-
2,6-dimethylbenzyl isocyanuric acid, 2,2-
(3,4′-dihydroxyphenyl) propane, bis (4-hydroxy-3-methylphenyl) sulfide,
4- {β- (p-methoxyphenoxy) ethoxy} salicylic acid, 1,7-bis (4-hydroxyphenylthio)
3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, phthalic acid monobenzyl ester monocalcium salt, 4,4′-cyclohexylidene diphenol, 4,4′- Isopropylidene bis (2-chlorophenol), 2,2'-methylene bis (4-methyl-6-tert-butylphenol), 4,4'-butylidene bis (6-tert-butyl-2-methylphenol),

1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) 1,1,3-tris (2-methyl-4-hydroxy-5)
-Cyclohexylphenyl) butane, 4,4'-thiobis (6-tert-butyl-2-methylphenol),
4,4'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4-benzyloxy-4'-hydroxydiphenyl sulfone, 4,4 '
-Diphenol sulfoxide, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,3-bis (4-hydroxyphenylthio) propane, N, N'-diphenylthiourea, N, N'-di (m-chlorophenyl) thiourea, salicylanilide, methyl bis- (4-hydroxyphenyl) acetate, bis (4-hydroxyphenyl) benzyl acetate,

1,3-bis (4-hydroxyphenyl)
Benzene, 1,4-bis (4-hydroxyphenyl) benzene, 2,4'-diphenol sulfone, 2,2'-
Diallyl-4,4′-hydroxyphenyl sulfone,
3,4-dihydroxy-4′-methyldiphenyl sulfone, 1-acetyloxy-2-naphthoate zinc, 2-acetyloxy-3-naphthoate zinc, 2-acetyloxy-1-naphthoate zinc, 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 produce the heat-sensitive recording material of the present invention, a leuco dye, a color developer, the compound of the present invention and other auxiliaries may be supported and bound on a support. As the binder in this case, various conventional binders can be used in appropriate amounts, and specific examples thereof include the following. Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, sodium polyacrylate,
Polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, poly In addition to water-soluble polymers such as acrylamide, sodium alginate, gelatin, and casein,
Emulsion of polyvinyl acetate, polyurethane, polyacrylic acid ester, polymethacrylic acid ester, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl acetate copolymer and the like, latex of styrene / butadiene / acrylic copolymer and the like.

Further, in the present invention, various heat fusible substances may be used in combination as a sensitivity improver and the like.
Specific examples thereof include the following, but the invention is 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, 1-hydroxy-
Phenyl 2-naphthoate, methyl 1-hydroxy-2-naphthoate, diphenyl carbonate, glare coal carbonate, dibenzyl 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-diphenoxybutane,
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) biphenyl, p-aryloxybiphenyl, 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, bis (4-chlorobenzyl oxalate) and the like.

In the case of obtaining a heat-sensitive recording material according to the present invention, a leuco dye, a color developer, and the compound of the present invention are optionally added together with an additive component which is commonly used in this kind of heat-sensitive recording material.
For example, a filler, a surfactant, a lubricant, a pressure color-developing inhibitor, etc. can be used in combination. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, inorganic fine powder such as surface-treated calcium or silica, and urea. -Organic fine powders such as formalin resin, styrene / methacrylic acid copolymer, polystyrene resin and vinylidene chloride resin can be mentioned. As the lubricant, higher fatty acid and its metal salt, higher fatty acid amide, higher fatty acid ester can be used. , Various animal, vegetable, mineral or petroleum waxes.

In the present invention, a layer containing a pigment, a binder, a heat-fusible substance and the like can be provided as another intermediate layer between the intermediate layer and the thermosensitive coloring layer, if necessary.

Further, in the recording material of the present invention, a protective layer may be provided on the heat-sensitive recording layer for the purpose of improving the storage stability of a recorded image and improving the writability on the recording material. In this case, the above-mentioned pigment, binder, heat-fusible substance or the like can be used as the component constituting the protective layer.

[0026]

EXAMPLES The present invention will now be described in more detail with reference to Examples. All parts and% shown below are based on weight.

Example 1 [Liquid A] Fine hollow particle dispersion 72 parts (Styrene-acryl-based copolymer resin) (Solid content concentration 27.5%, average particle diameter 1 μm, hollow ratio 50%) Styrene / Butadiene copolymer latex 21 parts (solid content concentration 47.5%) Water 7 parts A mixture comprising the above-mentioned composition was stirred and dispersed to prepare an intermediate layer forming liquid.

[0028]     [B liquid]       3-dibutylamino-6-methyl-7-anilinofluorane 20 parts       20 parts of 10% aqueous solution of polyvinyl alcohol       60 parts of water

[0029]     [C liquid]       4-isopropoxy-4'-hydroxydiphenyl sulfone 10 parts       Bis (4-methylbenzyl) oxalate 5 parts       30 parts of 10% aqueous solution of polyvinyl alcohol       15 parts calcium carbonate       40 parts of water

[B liquid] and [C liquid] were prepared by dispersing the mixture composed of the above composition using a sand mill so that the average particle diameter was 1.5 μm or more and 2.5 μm or less. 10 parts of [B solution] and 30 parts of [C solution] were mixed to prepare coating solutions for the thermosensitive coloring layer.
Commercially available high-quality paper (basis weight: 52 g / m ² ) was coated and dried to give a weight of 5 g / m ² after drying to provide an intermediate layer, and then the heat-sensitive layer had a weight of 4.5 to 5 after drying. A thermosensitive color-developing layer was provided by coating and drying so that the coating amount became 0.5 g / m ² .

[0031]     [D liquid]       Cross-linked poly (methyl methacrylate) fine particles 10 parts       (Average particle size: 5 μm)       Kaolin 20 copies       (Average particle size: about 1 μm)       20 parts of 10% aqueous solution of polyvinyl alcohol       50 parts of water

A mixture comprising the above composition was dispersed using a sand mill to prepare a pigment dispersion liquid [D liquid].

[0033]     [Liquid E]       Liquid D 25 parts       40% aqueous solution of 10% polyvinyl alcohol       20 parts of epichlorohydrin resin (20%)       15 parts of water

A mixture having the above composition was stirred and dispersed to prepare a protective layer forming liquid. Next, a protective layer forming liquid is applied and dried on the thermosensitive coloring layer so that the dry weight is about 2 g / m ² , and the surface of the layer is calendered so that the smoothness is 500 to 2000 seconds. When a material was prepared and then the thickness of the protective layer was measured, a heat-sensitive recording material having a thickness of about 2 μm was obtained.

Example 2 Example 3 was carried out except that 3 parts of crosslinked polymethylmethacrylate fine particles (average particle size: 5 μm) and 27 parts of kaolin (average particle size: about 1 μm) were used in the D liquid of Example 1. A thermal recording material was obtained in the same manner as in Example 1.

[0036]

Example 3 In the preparation of solution D in Example 1, crosslinked polymethacrylic acid polymer was used.
10 parts of chill fine particles (average particle diameter: 5 μm)
6 parts of methyl acrylate fine particles (average particle diameter: 5 μm)
20 parts of Olin (average particle size: about 1 μm) is aluminum hydroxide
14 parts of aluminum (average particle size: about 1 μm) and 60 parts of water
A thermal recording material was obtained in the same manner as in Example 1 except for the above.

Example 4 In the preparation of liquid D of Example 1, 10 parts of crosslinked polymethylmethacrylate fine particles (average particle size: 5 μm), 12 parts, 20 parts of kaolin (average particle size: about 1 μm), 8 parts, water 6
A thermal recording material was obtained in the same manner as in Example 1 except that the content was 0 part.

Example 5 In the preparation of the liquid D of Example 1, 10 parts of crosslinked polymethylmethacrylate fine particles (average particle size: 5 μm), 1 part of polymethylmethacrylate fine particles (average particle size: 5 μm), kaolin (average Particle diameter: about 1 μm) A thermal recording material was obtained in the same manner as in Example 1 except that 20 parts was 19 parts and water was 60 parts.

Comparative Example 1 [F liquid] Crosslinked polymethylmethacrylate fine particles 10 parts (average particle diameter: 5 μm) 10% aqueous solution of polyvinyl alcohol 20 parts water 70 parts A mixture of the above composition was dispersed using a sand mill. A pigment dispersion liquid [F liquid] was prepared.

[Liquid G] Liquid F 20 parts 10% aqueous solution of polyvinyl alcohol 30 parts Epichlorohydrin resin (20%) 20 parts Water 30 parts Except that a mixture of the above components was stirred and dispersed to prepare a protective layer forming liquid. A thermal recording material was obtained in the same manner as in Example 1.

Comparative Example 2 In the preparation of the F liquid of Comparative Example 1, 10 parts of crosslinked polymethylmethacrylate fine particles (average particle size: 5 μm) were added to 25 parts of aluminum hydroxide (average particle size: about 1 μm), and 70 parts of water were added to 5 parts. .5 parts, in the preparation of G solution, 25 parts of F solution, 40 parts of 10% aqueous solution of polyvinyl alcohol, and 35 parts of water.
A thermal recording material was obtained in the same manner as in Comparative Example 1 except that the parts were used.

Comparative Example 3 In Example 3 , fine particles of polymethylmethacrylate (average particle size: 5 μm) were mixed with silica (average particle size: about 3 μm).
m), aluminum hydroxide (average particle size: about 1 μm), polymethylmethacrylate fine particles (average particle size: 1 μm)
A thermal recording material was obtained in the same manner as in Example 3 except that the above was adopted.

Ruled line deviation: My Report NT-50
Vertical ruled lines were printed with a serial printer capable of printing three lines of 0 (manufactured by Ricoh Co., Ltd.) and Oasis 30-LX701 (manufactured by Fujitsu Ltd.), and the deviation of the vertical ruled lines for each line was measured. Appearance ○: Almost no deviation is noticeable. Δ: There is a deviation, but there is no problem. X: The shift is noticeable. Color density: Printing was performed using a word processor serial printer, and the maximum color density was measured with Macbeth (RD-914). Matching: Printing was performed with a serial printer for word processing, and the head matching property with a serial printer such as a stick was observed. ◎: Very good ○: Good △: Not very good ×: Not good

[0045]

[Table 1]

[0046]

As is clear from the above detailed and specific description, the heat-sensitive recording material of the present invention has a problem that a heat-sensitive recording apparatus using a serial printing system has a large friction and a ruled line is likely to be displaced. Is further improved, and it is also extremely excellent in terms of color density and head matching property.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsunobu Morita No. 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) Reference JP-A-4-232091 (JP, A) JP Japanese Patent Laid-Open No. 5-278334 (JP, A) Japanese Patent Laid-Open No. 4-112082 (JP, A) Japanese Patent Laid-Open No. 3-205181 (JP, A) Japanese Patent Laid-Open No. 3-193485 (JP, A) Japanese Patent Laid-Open No. 3-176189 (JP , A) JP 6-64325 (JP, A) JP 8-156418 (JP, A) JP 7-96665 (JP, A) JP 5-185726 (JP, A) JP 4-64483 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41M 5 / 28-5 / 34

Claims (2)

(57) [Claims] 1. A thermosensitive recording material comprising a support and a thermosensitive coloring layer containing a leuco dye and a color developer as main components, and a protective layer containing a pigment and a resin as main components, which are sequentially laminated on the thermosensitive coloring layer. In the above, as the pigment to be contained in the protective layer, an acrylic resin having an average particle diameter of 1.0 times or more the thickness of the protective layer and an inorganic pigment having an average particle diameter of less than 1.0 times the thickness of the protective layer are used. for
Heat-sensitive recording materials, characterized in that there. 2. An average grain which is 1.0 times or more the thickness of the protective layer.
The thermosensitive recording material according to claim 1, wherein the acrylic resin having a child diameter is 3 to 15% by weight of the protective layer.