JPH08290663A - Thermal recording material - Google Patents

Abstract

PURPOSE: To provide a transparent or semi-transparent thermal recording material in which white stripes which is a problem specific to the case a plastic film is used as a support body can be ameliorated, a phenomenon that a component in a coat layer melts and adheres to a heat head (hereinafter called sticking) is not generated at the time of heat coloring, and attaching of residue is only a little. CONSTITUTION: In a transparent or semi-transparent thermal recording material, a thermal coloring layer which contains, as main components, a leuco dye, a developer for developing the color of the leuco dye with heat, and a binder resin as a binding agent is formed on a transparent or semi-transparent plastic film, and a protective layer is provided on the thermal coloring layer. The coefficient of dynamic friction of the surface of the protective layer is 0.4-0.8 and the transparency of the thermal recording material is 40% or lower in HAZE degree by JIS 7105.

Description

Detailed Description of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording medium utilizing a color-developing reaction between an electron-donating color-forming compound and an electron-accepting compound, which is a heat-sensitive recording material having high density and excellent head matching property. It is about.

[0003]

2. Description of the Related Art Various recording materials have been proposed which utilize a color-forming reaction between a colorless or light-colored leuco dye and a color-developing agent which develops color upon contact by heat or pressure. One of the heat-sensitive recording materials is that they do not require complicated processing such as development and fixing, can be recorded in a short time with a relatively simple device, generate little noise, and have low cost. It is useful as various recording materials for electronic calculators, facsimiles, ticket vending machines, label printers, recorders and the like. As the color-forming dye used in the heat-sensitive recording material, for example, a colorless or light-colored leuco dye having a lactone, a lactam or a spiropyran ring, and as a developer, an organic acid, a phenolic substance, or the like has been conventionally used. The heat-sensitive recording material using the leuco dye and the color developer is widely used because of its high image density and high whiteness of the background. These heat-sensitive recording materials are generally manufactured by coating the above-mentioned color-forming dye and developer on paper. For example, in Japanese Patent Laid-Open No. 61-274987,
In order to improve the color density and image quality (dot reproducibility) of the thermal recording paper, supercalender it on the paper support or
Alternatively, by pressing a wet paper after pressing or a paper moistened with water on a smooth Yankee dryer and drying,
JIS-B when the density of the paper support is 0.98 g / cm ³ or less
It is described that the center line average roughness (at a wavelength of 250 μm) based on 0601 is 0.70 μm or less. JP-A-56-37190 discloses that adhesion of dust, tailing,
It is described that the coefficient of static friction of the surface of the thermosensitive color developing layer is 0.50 to 0.64 in order to improve the image density reduction, the image distortion, and the abrasion of the hot pen or the thermal head. Japanese Patent Laid-Open No. 63-317383 provides an excellent thermal recording sheet which does not generate noise exceeding about 60 dB even in a high speed miniaturized thermal recording apparatus. Therefore, the recording surface of the thermal recording sheet has a Beck smoothness of 10 seconds to 150 seconds. In contact with a substrate having a surface of J. TAPPI paper pulp test method No. When measuring the dynamic friction coefficient based on 30,
It is described that all the amplitudes of the dynamic friction force curve are 0.05 kgf or less.
No. 2 discloses an optical surface roughness (R) of the thermal recording paper in order to eliminate sticking between the thermal head and the thermal coloring layer during high speed recording on the thermal recording paper and piling on the thermal head.
It is described that a heat-sensitive coating liquid is applied on a light-weight coated paper having a p value of 8 μm or less and a thickness of 40 μm or more and 75 μm or less. Further, JP-A-4-175186 discloses that a heat-sensitive coating solution is applied on a support. The optical surface roughness (Rp) of the heat-sensitive recording material provided with a coloring layer containing a leuco dye and a color developer as main components.
Value), that is, "a method for measuring the printing smoothness of paper mainly on the optical contact method" written by Shinpei Sakuramoto, Research Institute of Printing Bureau, Ministry of Finance, No. 2
Paper when a prism is pressure-bonded to paper by using "Microtopograph" manufactured by Toyo Seiki Seisakusho Co., Ltd. as an apparatus according to the measurement principle described in Volume 9, No. 9, pages 615 to 622 (September 1977). Of the surface roughness of the prism is 0.8 kg / cm ² and the value optically measured 100 milliseconds after the pressure is 0.85 μmm or less, and the thermal conductivity (λ) is 0. It is described that it is set to 0.70 w / mk or less. However, in recent years, along with the diversification of applications, not only paper but also transparent plastic films are often used as a support. Examples of such a plastic film used as a support include recording materials for video printers and OHP films. The thermal recording material using a plastic film as a support,
Compared to the case where paper is used as a support, the adhesion between the recording material and the thermal head is good and the color development is good, but on the other hand, dust or dirt is likely to adhere to the surface of the recording material. Phenomenon (generated by melting the components in the coating layer at the time of color development) that is generated at the time of printing is caught between the thermal recording material and the thermal head during printing, and the image appears as streaks in that part and its vicinity (hereinafter white It is called streak.)
Is likely to occur.

[0004]

The object of the present invention is to improve the white streak, which is a problem peculiar to the case where a plastic film is used as a support, and at the same time, the components in the coating layer are melted at the time of color development by heating to cause a thermal head. Another object of the present invention is to provide a transparent or semi-transparent heat-sensitive recording material which does not have a phenomenon of sticking to the surface (hereinafter referred to as sticking) and has little dust adhesion.

[0005]

The object of the present invention is to provide "a leuco dye on a transparent or translucent plastic film, a developer that heat-colors the leuco dye and a binder resin as a binder. In a transparent or translucent thermosensitive recording material comprising a thermosensitive coloring layer as a main component and a protective layer formed thereon, the coefficient of kinetic friction of the protective layer surface is 0.4 to 0.8. Material transparency is JI
A thermosensitive recording material having a HAZE degree of 40% or less according to S7105 "," leuco dye on a transparent or translucent plastic film, and as a developer and a binder for heating and coloring the leuco dye. In a transparent or semi-transparent heat-sensitive recording material having a thermosensitive coloring layer containing the binder resin as a main component and a protective layer thereon, the optical surface roughness Rp of the protective layer surface is 0.9 to 1. 3 μm, the coefficient of dynamic friction of the surface of the protective layer is 0.4 to 0.8, and the transparency of the heat-sensitive recording material is H according to JIS7105.
"Thermal recording material characterized by having an AZE degree of 40% or less", "Leuco dye on a transparent or semitransparent plastic film, a developer as a color developer and a binder for heating the leuco dye to form a color, and a binder as a binder. A thermosensitive coloring layer containing a resin as a main component, and a transparent or translucent thermosensitive recording material further provided with a protective layer thereon, wherein the silicone-modified resin and the inorganic filler are contained in an amount of 50% by weight or more based on the total weight of the protective layer. The coefficient of dynamic friction of the surface of the protective layer is 0.4 to 0.8, and the transparency of the thermosensitive recording material is H according to JIS7105.
"Thermal recording material characterized by having an AZE degree of 40% or less", "Leuco dye on a transparent or semitransparent plastic film, a developer as a color developer and a binder for heating the leuco dye to form a color, and a binder as a binder. In a transparent or translucent thermosensitive recording material comprising a thermosensitive coloring layer containing a resin as a main component and a protective layer formed thereon, the optical surface roughness Rp of the protective layer surface is 0.9 to 1.3 μm. 50% by weight of the silicone modified resin and the inorganic filler with respect to the total weight of the protective layer
The coefficient of dynamic friction on the surface of the protective layer is 0.4 to 0.
8, the transparency of the heat-sensitive recording material is a value of 40% or less in Haze degree according to JIS 7105 "," Leuco dye on transparent or translucent plastic film, the leuco dye In a transparent or translucent thermosensitive recording material comprising a thermosensitive color developing layer mainly composed of a binder resin as a color developer and a binder that heat-colors, and a protective layer provided thereon, the total weight of the protective layer is On the other hand, a silicone modified resin and an inorganic filler are contained in an amount of 50% by weight or more, and the inorganic filler in the protective layer is silica having a volume average particle diameter of 0.1 to 0.3 μm and / or silica coated with calcium. The coefficient of kinetic friction of the surface of the protective layer is 0.4 to 0.8, and the transparency of the thermosensitive recording material is a value of 40% or less in Haze degree according to JIS7105. Thermosensitive recording material "," a leuco dye on a transparent or translucent plastic film, a color developing agent that heat-develops the leuco dye and a thermosensitive coloring layer mainly containing a binder resin as a binder, and further thereon In a transparent or translucent heat-sensitive recording material provided with a protective layer, the optical surface roughness Rp of the protective layer surface is 0.9 to 1.
Silica having a volume average particle diameter of 0.1 to 0.3 μm, wherein the silicone-modified resin and the inorganic filler are contained in an amount of 50% by weight or more based on the total weight of the protective layer. And / or calcium-coated silica having a dynamic friction coefficient of 0.4 to 0.8 on the surface of the protective layer.
The heat-sensitive recording material is characterized in that the transparency of the heat-sensitive recording material is a value of 40% or less in Haze degree according to JIS 7105 "," Leuco dye on the transparent or translucent plastic film, the leuco dye In a transparent or semi-transparent heat-sensitive recording material comprising a thermosensitive color developing layer containing a binder resin as a color developer and a binder as a main component for color development by heating, and further providing a protective layer thereon, based on the total weight of the protective layer. A silicone modified resin and an inorganic filler are contained in an amount of 50% by weight or more, and the inorganic filler in the protective layer is silica having a volume average particle diameter of 0.1 to 0.3 μm and / or silica coated with calcium. The dynamic friction coefficient of the surface of the protective layer is 0.4 to 0.8, and the transparency of the heat-sensitive recording material is a value of 40% or less in the HAZE degree according to JIS7105. Thermal recording material "," Leuco dye on transparent or semi-transparent plastic film, thermosensitive coloring layer mainly composed of leuco dye that heat-colors the leuco dye and binder resin as a binder, and further protective layer In a transparent or semitransparent heat-sensitive recording material having a layer, the protective layer has an optical surface roughness Rp of 0.9 to 1.
Silica having a volume average particle diameter of 0.1 to 0.3 μm, wherein the silicone-modified resin and the inorganic filler are contained in an amount of 50% by weight or more based on the total weight of the protective layer. And / or calcium-coated silica having a dynamic friction coefficient of 0.4 to 0.8 on the surface of the protective layer.
The heat-sensitive recording material is characterized in that the transparency of the heat-sensitive recording material is a value of 40% or less in Haze degree according to JIS 7105 "," Leuco dye on the transparent or translucent plastic film, the leuco dye In a transparent or semi-transparent heat-sensitive recording material comprising a thermosensitive color developing layer containing a binder resin as a color developer and a binder as a main component for heating color development, and a protective layer formed thereon, the dynamic friction coefficient of the surface of the protective layer. Is 0.4 to 0.8, the transparency of the heat-sensitive recording material is 40% or less in the HAZE degree according to JIS7105, and the developer is an organic phosphoric acid represented by the following general formula (1). "A thermosensitive recording material characterized by being a compound" and "a leuco dye on a transparent or translucent plastic film, a developer as a color developer and a binder for heating and coloring the leuco dye, and a binder. In a transparent or translucent heat-sensitive recording material comprising a thermosensitive coloring layer containing a resin as a main component and a protective layer formed thereon, the developer is an organic phosphoric acid compound represented by the following general formula (1). The optical surface roughness Rp of the protective layer surface is 0.9 to 1.3 μm, the dynamic friction coefficient of the protective layer surface is 0.4 to 0.8, and the transparency of the thermosensitive recording material is It is achieved by a heat-sensitive recording material characterized by having a HAZE degree of 40% or less according to JIS7105.

[0006]

[General formula 1] (R ₁ represents a linear alkyl group having 12 to 24 carbon atoms) Here, the dynamic friction coefficient of the surface of the protective layer is a HEIDON surface property tester using a load of 1 kg and a pulling speed of 75 mm.
It is a value obtained by performing a ball indenter test under the condition of / min. The Haze degree is a value according to JIS7105, and in the heat-sensitive recording material of the present invention, this value is preferably 40% or less. Here, JIS-7
The HAZE degree (haze value) defined in 105 is the diffuse transmittance and total light transmittance of the test piece using the integrating sphere type light transmittance measuring device that is specified for measuring the light transmittance during the measurement. The rate is measured and the following formula is given: (In the formula, H is a base (cloudiness value) (%), Td is a diffuse transmittance (%), and Ti is a total light transmittance.). Then, the white streak in the present invention, as described above, the dust on the surface of the recording material or the head dust generated during printing is sandwiched between the thermal recording material and the thermal head during printing, and in that portion and in the vicinity thereof. This is a phenomenon in which an image is striped. The inventors of the present invention have conducted studies to improve this phenomenon. As a result, the dynamic friction coefficient of the protective layer surface is related to white streak and sticking, and when the dynamic friction coefficient of the protective layer surface is 0.4 or more, the white streak is large. The present invention was completed by finding that the occurrence of sticking is less likely to occur and that the sticking is less likely to occur at 0.8 or less. The coefficient of dynamic friction on the surface of the protective layer is set to 0.
4 or more and 0.8 or less can be achieved by adding waxes to the protective layer or using a resin modified with silicon to lower the dynamic friction coefficient, or conversely, by adding a filler, the dynamic friction coefficient. It can be adjusted by raising. As waxes that can be used here, stearic acid amide, palmitic acid amide, oleic acid amide, lauric acid amide, ethylene bis stearoamide, methylene bis stearoamide, methylol stearoamide, paraffin wax, polyethylene, carnauba. Wax, oxidized paraffin, zinc stearate, etc. may be mentioned. Examples of the filler that can be used here include silica, kaolin, clay, talc, calcium carbonate, calcined clay, aluminum hydroxide, and urea-formalin resin. As described above, according to the present invention, the optical surface roughness Rp of the protective layer surface is 0.9 to 1.3.
There is provided a thermosensitive recording material characterized by having a thickness of μm. The optical surface roughness Rp is a value measured under the condition of a pressing force of 13.5 kgf / cm ² using a Toyo Seiki Microtopograph. Optical surface roughness Rp is 0.9μ
If it is more than m, the effect on white lines is further increased, 1.3 μm
If it is above, the transparency is significantly lowered. As a method of setting the optical surface roughness Rp of the protective layer surface to 0.9 to 1.3 μm, a filler is added to the protective layer or the recording layer, or a plastic film which has been subjected to a rough surface treatment beforehand is used, There is a method in which a protective layer is applied and dried, and then the surface is roughened. Further, as described above, the protective layer further comprises a silicone modified resin and an inorganic filler (the silicone modified resin and the inorganic filler are contained in an amount of 50% by weight or more based on the total weight of the protective layer). A material, and a heat-sensitive recording material characterized in that the volume average particle diameter of the inorganic filler is 0.1 to 0.3 μm, and further, the inorganic filler is silica and / or calcium is coated silica. A thermal recording material is provided. Details of the thermosensitive recording medium of the present invention will be described. The support used in the present invention is not particularly limited, polyethylene terephthalate, polyester film such as polybutylene terephthalate,
It is a cellulose derivative film such as cellulose triacetate, a polyolefin film such as polypropylene or polyethylene, a polystyrene film or a transparent film obtained by laminating these films, or a film such as general paper or synthetic paper. The color former used in the present invention is a compound exhibiting an electron donating property, and is applied alone or in combination of two or more kinds.
It is a colorless or light-colored dye precursor per se, and is not particularly limited and conventionally known ones, for example, triphenylmethanephthalide-based, triallylmethane-based, fluorane-based, phenothidian-based, thioferolane-based, xanthene-based, indophthalyl. , Leuco compounds such as spiropyrans, azaphthalides, chromenopyrazoles, methines, rhodamine anilinolactams, rhodamine lactams, quinazolines, diazaxanthenes, and bislactones are preferably used. Examples of such compounds include those shown below. 2-anilino
3-Methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6- (di-n-butylamino) fluorane, 2-anilino-3-methyl-6- (Nn-propyl-N-methyl) Amino) fluorane, 2-anilino-3-methyl-6- (N-isopropyl-N-methylamino) fluorane, 2-anilino-3-methyl-6-
(N-isobutyl-N-methylamino) fluorane, 2
-Anilino-3-methyl-6- (Nn-amyl-N-
Methylamino) fluorane, 2-anilino-3-methyl-6- (N-sec-butyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (Nn-amyl-N-ethylamino) ) Fluoran, 2-anilino-
3-Methyl-6- (N-isoamyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (N
-N-propyl-N-isopropylamino) fluorane, 2-anilino-3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane, 2-anilino-
3-Methyl-6- (N-ethyl-p-toluidino) fluorane, 2-anilino-3-methyl-6- (N-methyl-p-toluidino) fluorane, 2- (m-trichloromethylanilino) -3-methyl -6-Diethylaminofluorane, 2- (m-trifluoromethylanilino) -3
-Methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl-6- (N-
Cyclohexyl-N-methylamino) fluorane, 2-
(2,4-Dimethylanilino) -3-methyl-6-diethylaminofluorane, 2- (N-ethyl-ptoluidino) -3-methyl-6- (N-ethylanilino) fluorane, 2- (N-methyl) -P-toluidino) -3-methyl-6- (N-propyl-p-toluidino) fluorane, 2-anilino-6- (Nn-hexyl-N-ethylamino) fluorane, 2- (o-chloroanilino)-
6-diethylaminofluorane, 2- (o-bromoanilino) -6-diethylaminofluorane, 2- (o-chloroanilino) -6-dibutylaminofluorane, 2-
(O-Fluoroanilino) -6-dibutylaminofluorane, 2- (m-trifluoromethylanilino) -6-diethylaminofluorane, 2- (p-acetylanilino) -6- (Nn-amyl-N) -N-butylamino)
Fluoran, 2-benzylamino-6- (N-ethyl-
p-toluidino) fluorane, 2-benzylamino-6
-(N-methyl-2,4-dimethylanilino) fluorane, 2-benzylamino-6- (N-ethyl-2,4-
Dimethylanilino) fluorane, 2-dibenzylamino-6- (N-methyl-ptoluidino) fluorane, 2
-Dibenzylamino-6- (N-ethyl-p-toluidino) fluorane, 2- (di-p-methylbenzylamino) -6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -6- (N-Ethyl-ptoluidino) fluorane, 2-methylamino-6- (N-methylanilino) fluorane, 2-methylamino-6- (N-ethylanilino) fluorane, 2-
Methylamino-6- (N-propylanilino) fluorane, 2-ethylamino-6- (N-methyl-ptoluidino) fluorane, 2-methylamino-6- (N-methyl-2,4-dimethylanilino) ) Fluoran, 2-ethylamino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2-dimethylamino-6- (N-methylanilino) fluorane, 2-dimethylamino-6-
(N-ethylanilino) fluorane, 2-diethylamino-6- (N-methyl-ptoluidino) fluorane,
2-Diethylamino-6- (N-ethyl-p-toluidino) fluorane, 2-dipropylamino-6- (N-methylanilino) fluorane, 2-dipropylamino-6
-(N-ethylanilino) fluorane, 2-amino-6
-(N-methylanilino) fluorane, 2-amino-6
-(N-ethylanilino) fluorane, 2-amino-6
-(N-propylanilino) fluorane, 2-amino-
6- (N-methyl-p-toluidino) fluorane, 2-
Amino-6- (N-ethyl-ptoluidino) fluorane, 2-amino-6- (N-propyl-ptoluidino) fluorane, 2-amino-6- (N-methyl-p-ethylanilino) fluorane, 2-amino- 6- (N-
Ethyl-p-ethylanilino) fluorane, 2-amino-6- (N-propyl-p-ethylanilino) fluorane, 2-amino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-Ethyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-propyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-methyl-p-chloroanilino) Fluorane, 2-amino-6- (N-ethyl-p-chloroanilino) fluorane, 2-amino-6-
(N-propyl-p-chloroanilino) fluorane,
2,3-Dimethyl-6-dimethylaminofluorane 3-
Methyl-6- (N-ethyl-ptoluidino) fluorane, 2-chloro-6-diethylaminofluorane, 2-
Bromo-6-diethylaminofluorane, 2-chloro-
6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2-chloro-6- (N-
Ethyl-N-isoamylamino) fluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-
Anilino-3-chloro-6-diethylaminofluorane, 2- (o-chloroanilino) -3-chloro-6-cyclohexylaminofluorane, 2- (m-trifluoromethylanilino) -3-chloro-6-diethylaminofluor Oran, 2- (2,3-dichloroanilino) -3-chloro-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 1,2-benzo-6
-(N-ethyl-N-isoamylamino) fluorane,
1,2-benzo-6-dibutylaminofluorane, 1,
2-benzo-6- (N-ethyl-N-cyclohexylamino) fluorane, 1,2-benzo-6- (N-ethyl-toluidino) fluorane, and others. Specific examples of other color formers preferably used in the present invention are as follows. 2-anilino-3-methyl-6- (N-2-
Ethoxypropyl-N-ethylamino) fluorane, 2
-(P-chloranilino) -6- (N-n-octylamino) fluorane, 2- (p-chloranilino) -6-
(Nn-paltimylamino) fluorane, 2- (p-chloroanilino) -6- (di-n-octylamino) fluorane, 2-benzoylamino-6- (N-ethyl-
p-toluidino) fluorane, 2- (o-methoxybenzoylamino) -6- (N-ethyl-p-toluidino)
Fluoran, 2-dibenzylamino-4-methyl-6-
Diethylaminofluorane, 2-dibenzylamino-4
-Methoxy-6- (N-methyl-p-toluidino) fluorane, 2-dibenzylamino-4-methyl-6- (N
-Ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -4-methyl-6-diethylaminofluorane, 2- (p-toluidino) -3- (t-butyl) -6- (N-methyl-p) Toluidino) fluorane, 2- (o-methoxycarbonylanilino) -6-diethylaminofluorane, 2-acetylamino-6-
(N-methyl-p-toluidino) fluorane, 3-diethylamino-6- (m-trifluoromethylanilino)
Fluorane, 4-methoxy-6- (N-ethyl-p-toluidino) fluorane, 2-ethoxyethylamino-3
-Chloro-6-dibutylaminofluorane, 2-dibenzylamino-4-chloro-6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenylethylamino) -4-chloro-6-diethylaminofluor Oran, 2
-(N-benzyl-p-trifluoromethylanilino)-
4-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-6-pyrrolidinofluorane, 2-anilino-3-chloro-6-pyrrolidinofluorane, 2-
Anilino-3-methyl-6- (N-ethyl-N-tetrahydrofurfurylamino) fluorane, 2-mesitidino-4 ', 5'-benzo-6-diethylaminofluorane, 2- (m-trifluoromethylanilino ) -3-Methyl-6-pyrrolidinofluorane, 2- (α-naphthylamino) -3,4-benzo-4′-bromo-6- (N-benzyl-N-cyclohexylamino) fluorane, 2-
Piperidino-6-diethylaminofluorane, 2- (N
-N-propyl-p-trifluoromethylanilino) -6
-Morpholinofluorane, 2- (di-N-p-chlorophenyl-methylamino) -6-pyrrolidinofluorane, 2- (N-n-propyl-m-trifluoromethylanilino) -6-morpholinoflu Oran, 1,2-benzo-6- (N-ethyl-Nn-octylamino) fluorane, 1,2-benzo-6-diallylaminofluorane, 1,2-benzo-6- (N-ethoxyethyl -N-
Ethylamino) fluorane, benzoleucomethylene blue 2- {3,6-bis (diethylamino)}-6- (o-chloroanilino) xanthyl lactam benzoate, 2-
{3,6-bis (diethylamino)}-9- (o-chloroanilino) xanthyl lactam benzoate, 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-
(2-Methoxy-4-dimethylaminophenyl) -3-
(2-hydroxy-4,5-dichlorophenyl) phthalide, 3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide, 3- (2-hydroxy-) 4-dimethoxyaminophenyl) -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, 3,6-bis (dimethylamino) fluorene spiro (9,3 ′)-6′-dimethylaminophthalide, 6′-chloro-8′-methoxy-benzoindolino-spiropyran, 6 '-Bromo-2'-methoxy-benzoindolino-spiropyran and the like. Next, the color developer used in the present invention is an electron-accepting compound, and various conventionally known electron-accepting color developers can be used. It is an electron-accepting developer containing a long-chain alkyl group in the molecule, as disclosed in Japanese Patent No. 124360. For example, an organic phosphoric acid compound, an aliphatic carboxylic acid compound or a phenol compound having an aliphatic group having 12 or more carbon atoms, or a metal salt of mercaptoacetic acid having an aliphatic group having 10 to 18 carbon atoms, or 5 to 8 carbon atoms. Alkyl ester of caffeic acid with 1 alkyl group and 1 carbon
Examples thereof include acidic organic phosphates having 6 or more aliphatic groups. The aliphatic group includes a linear or branched alkyl group and alkenyl group, and may have a substituent such as a halogen, an alkoxy group and an ester. Specific examples of the developer will be illustrated below. (A) Organic Phosphoric Acid Compound In the present invention, an organic phosphoric acid compound represented by the following general formula (1) is preferably used.

[0007]

[General formula 1] (R ₁ represents a linear alkyl group having 12 to 28 carbon atoms) Specific examples of the organic phosphoric acid compound represented by the general formula (1) include the following. Dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, docosylphosphonic acid, tetracosylphosphonic acid, hexacosylphosphonic acid, octacosylphosphonic acid and the like. As the organic phosphoric acid compound, α-hydroxyalkylphosphonic acid represented by the following general formula (2) is also preferably used.

[0008]

[General formula 2] (However, R ₂ is an aliphatic group having 11 to 29 carbon atoms.) Specific examples of the α-hydroxyalkylphosphonic acid represented by the general formula (2) include α-hydroxydodecylphosphonic acid and α-hydroxytetracarboxylic acid. Examples thereof include decylphosphonic acid, α-hydroxyhexadecylphosphonic acid, α-hydroxyoctadecylphosphonic acid, α-hydroxyeicosylphosphonic acid, α-hydroxydocosylphosphonic acid, and α-hydroxytetracosylphosphonic acid. Also,
As the organic phosphoric acid compound, an acidic organic phosphoric acid ester represented by the following general formula (3) is also preferably used.

[0009]

[General formula 3] (In the formula, R ₃ represents an aliphatic group having 16 or more carbon atoms, and R ₄ represents a hydrogen atom or an aliphatic group having 1 or more carbon atoms.) An acidic organic phosphate ester represented by the general formula (3) Specifically, dihexadecyl phosphate, dioctadecyl phosphate, dieicosyl phosphate, didocosyl phosphate, monohexadecyl phosphate,
Examples include monooctadecyl phosphate, monoeicosyl phosphate, monodocosyl phosphate, methyl hexadecyl phosphate, methyl octadecyl phosphate, methyl eicosyl phosphate, methyl docosyl phosphate, amyl hexadecyl phosphate, octyl hexadecyl phosphate, and lauryl hexadecyl phosphate. To be

(B) Aliphatic carboxylic acid compound In the present invention, as the aliphatic carboxylic acid compound, α-hydroxy fatty acids represented by the following general formula (4) are preferably used.

[0011]

[General formula 4] (However, R ₅ represents an aliphatic group having 12 or more carbon atoms.) Examples of the α-hydroxy aliphatic carboxylic acid compound represented by the general formula (4) include the following.
α-hydroxydecanoic acid, α-hydroxytetradecanoic acid, α-hydroxyhexadecanoic acid, α-hydroxyoctadecanoic acid, α-hydroxypentadecanoic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α
-Hydroxytetracosanoic acid, α-hydroxyhexacosanoic acid, α-hydroxyoctacosanoic acid, etc. As the aliphatic carboxylic acid compound, an aliphatic carboxylic acid compound having an aliphatic group having 12 or more carbon atoms which is substituted with a halogen element and having a halogen element at at least the α-position or β-position carbon is also preferable. Used. Specific examples of such a compound include the followings. 2-bromohexadecanoic acid, 2-bromoheptadecanoic acid, 2-bromooctadecanoic acid, 2-bromoeicosanoic acid, 2-bromodocosanoic acid, 2-bromotetracosanoic acid, 3-bromooctadecanoic acid, 3-bromoeicosanoic acid 2,3-dibromooctadecanoic acid, 2-fluorododecanoic acid, 2-fluorotetradecanoic acid, 2-fluorohexadecanoic acid, 2-fluorooctadecanoic acid, 2
-Fluoroeicosanoic acid, 2-fluorodocosanoic acid, 2
-Iodohexadecanoic acid, 2-iodooctadecanoic acid,
3-iodohexadecanoic acid, 3-iodooctadecanoic acid, perfluorooctadecanoic acid and the like. Further, the aliphatic carboxylic acid is an aliphatic carboxylic acid compound having an aliphatic group having 12 or more carbon atoms and having an oxo group in carbon, and at least the carbon at the α-position, β-position or γ-position becomes an oxo group. Those that are used are also preferably used. Specific examples of such a compound include the followings. 2-oxododecanoic acid, 2-oxotetradecanoic acid, 2-oxohexadecanoic acid, 2-oxooctadecanoic acid, 2-oxoeicosanoic acid, 2-oxotetracosanoic acid, 3-oxododecanoic acid, 3-oxotetradecanoic acid, 3-oxohexadecanoic acid, 3-oxooctadecanoic acid, 3-oxoeicosanoic acid, 3-oxotetracosanoic acid, 4-oxohexadecanoic acid, 4-oxooctadecanoic acid, 4-oxodocosanoic acid and the like. Further, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (5) is also preferably used.

[0012]

[General formula 5] (However, R ₆ represents an aliphatic group having 12 or more carbon atoms,
X represents an oxygen atom or a sulfur atom, and n represents 1 or 2. Specific examples of the dibasic acid represented by the general formula (5) include:
For example: Dodecylmalic acid, tetradecylmalic acid, hexadecylmalic acid, octadecylmalic acid, eicosylmalic acid, docosylmalic acid, tetracosylmalic acid, dodecylthiomalic acid, tetradecylthiomalic acid, hexadecylthiomalic acid,
Octadecyl thiomalic acid, eicosyl thiomalic acid,
Docosylthiomalic acid, tetracosylthiomalic acid, dodecyldithiomalic acid, tetradecyldithiomalic acid,
Eicosyl dithiomalic acid, docosyl dithiomalic acid,
Tetracosyldithiomalic acid, etc. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (6) is also preferably used.

[0013]

[General formula 6] (However, R ₇ , R ₈ , and R ₉ represent hydrogen or an aliphatic group, at least one of which is an aliphatic group having 12 or more carbon atoms.) Specific examples of the dibasic acid represented by the general formula (6) For example,
For example: Dodecyl butanedioic acid,
Tridecyl butanedioic acid, tetradecyl butanedioic acid, pentadecyl butanedioic acid, octadecyl butanedioic acid, eicosyl butanedioic acid, docosyl butanedioic acid, 2,3-dihexadecyl butanedioic acid, 2,3-dioctadecyl Butanedioic acid, 2-methyl-3-dodecylbutanedioic acid, 2-methyl-3-tetradecylbutanedioic acid, 2-methyl-3-hexadecylbutanedioic acid, 2-ethyl-3-dodecylbutanedioic acid, 2-propyl-3-dodecylbutanedioic acid, 2-octyl-3-hexadecylbutanedioic acid, 2-tetradecyl-3-octadecylbutanedioic acid and the like. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (7) is also preferably used.

[0014]

[General formula 7] (However, R ₁₀ and R ₁₁ represent hydrogen or an aliphatic group, at least one of which is an aliphatic group having 12 or more carbon atoms.) Specific examples of the dibasic acid represented by the general formula (7) ,
For example, the following may be mentioned. Dodecylmalonic acid, tetradecylmalonic acid, hexadecylmalonic acid, octadecylmalonic acid, eicosylmalonic acid, docosylmalonic acid, tetracosylmalonic acid, didotecilmalonic acid,
Ditetradecylmalonic acid, dihexadecylmalonic acid, dioctadecylmalonic acid, dieicosylmalonic acid, didocosylmalonic acid, methyloctadecylmalonic acid, methyldocosylmalonic acid, methyltetracosylmalonic acid, ethyloctadecylmalonic acid, ethyl Eicosyl malonic acid, ethyl docosyl malonic acid, ethyl tetracosyl malonic acid, etc. Furthermore, as the aliphatic carboxylic acid compound, a dibasic acid represented by the following general formula (8) is also preferably used.

[0015]

[General formula 8] (However, R ₁₂ represents hydrogen or an aliphatic group, n represents 0 or 1, m represents 1, 2 or 3, and when n is 0, m is 2 or 3 and n is 1 If m is 1 or 2
As a specific example of the dibasic acid represented by the general formula (8),
For example, the following may be mentioned. 2-dodecyl-
Pentanedioic acid, 2-hexadecyl-pentanedioic acid, 2-
Octadecyl pentanedioic acid, 2-eicosyl-pentanedioic acid, 2-docosyl-pentanedioic acid, 2-dodecyl-hexanedioic acid, 2-pentadecyl-hexanedioic acid, 2-octadecyl-hexanedioic acid, 2-eicosyl-hexane. Diacid, 2-docosyl-hexanedioic acid and the like. Furthermore, as the aliphatic carboxylic acid compound, a tribasic acid such as citric acid acylated with a long chain fatty acid is also preferably used. Specific examples thereof include the following.

[0016]

[A] O-palmityl citric acid

[B] O-stearyl citric acid

[C] O-eicosyl enoic acid (C) Phenol compound In the present invention, a compound represented by the following general formula (9) is preferably used as the phenol compound.

[0017]

[General formula 9] (However, Y is -S-, -O-, -CONH-, or -C.
OO-, R ₁₃ represents an aliphatic group having 12 or more carbon atoms, and n is an integer of 1, 2 or 3) Specific examples of the phenol compound represented by the general formula (9) are shown below. Something like this. p- (dodecylthio) phenol, p- (tetradecylthio) phenol, p- (hexadecylthio) phenol, p- (octadecylthio) phenol, p- (eicosylthio) phenol, p- (docosylthio) phenol, p- (tetracosyl) Ruthio) phenol, p- (dodecyloxy) phenol, p- (tetradecyloxy) phenol, p- (hexadecyloxy) phenol, p- (octadecyloxy) phenol, p- (eicosyloxy) phenol, p- ( Docosyloxy)
Phenol, p- (tetracosyloxy) phenol,
p-dodecylcarbamoylphenol, p-tetradecylcarbamoylphenol, p-hexadecylcarbamoylphenol, p-octadecylcarbamoylphenol, p-eicosylcarbamoylphenol, p-docosylcarbamoylphenol, p-tetracosylcarbamoylphenol, hexa gallic acid Decyl ester,
Gallic acid octadecyl ester, gallic acid eicosyl ester, gallic acid docosyl ester, gallic acid tetracosyl ester, etc. As the phenol compound, a caffeic acid alkyl ester represented by the following general formula (10) can also be used.

[0018]

[General formula 10] (However, R ₁₄ is an alkyl group having 5 to 8 carbon atoms.) Specific examples of the caffeic acid alkyl ester represented by the general formula (10) include caffeic acid-n-ventil, caffeic acid-n-hexyl, and caffer. Acid-n-octyl etc. are mentioned. (D) Metal salt of mercaptoacetic acid In the present invention, a metal salt of an alkyl or alkenyl mercaptoacetic acid represented by the general formula (11) can be preferably used as the metal salt of mercaptoacetic acid.

[0019]

[General formula 11] (However, R ₁₅ represents an aliphatic group having 10 to 18 carbon atoms, and M represents tin, magnesium, zinc, or copper.) Specific examples of the mercaptoacetic acid metal salt represented by the general formula (11) include the following. Something like.
Decylmercaptoacetic acid tin salt, dodecylmarcaptoacetic acid tin salt, tetradecylmercaptoacetic acid tin salt, hexadecylmercaptoacetic acid tin salt, octadecylmercaptoacetic acid tin salt, decylmercaptoacetic acid megnesium salt, dodecylmercaptoacetic acid magnesium salt, tetradecylmercaptoacetic acid magnesium salt Salt, hexadecylmercaptoacetic acid magnesium salt, octadecylmercaptoacetic acid magnesium salt, decylmercaptoacetic acid zinc salt, dodecylmercaptoacetic acid zinc salt, tetradecylmercaptoacetic acid zinc salt, hexadecylmercaptoacetic acid zinc salt, octadecylmercaptoacetic acid zinc salt, decylmercaptoacetic acid Copper salt, dodecyl mercapto acetic acid copper salt, tetradecyl mercapto acetic acid copper salt, hexadecyl mercapto acetic acid copper salt, octadecyl mercapto acetic acid copper salt Etc..

Further, in the present invention, the color developer is not limited to the above-mentioned compounds, and various other compounds having electron accepting properties can be used. In the heat-sensitive recording medium of the present invention, the developer is used in an amount of 1 to 20 parts, preferably 2 to 10 parts, per 1 part of the color former. The color developer can be applied alone or in combination of two or more kinds, and also in the case of the color developer, it can be applied alone or in combination of two or more kinds.

Next, various known resins can be used as the binder resin in the thermosensitive coloring layer used in the present invention.
For example, polyacrylamide, maleic acid copolymer, polyacrylic acid ester, polymethacrylic acid ester,
Vinyl chloride / vinyl acetate copolymer, styrene copolymer,
Polyester, polyurethane, polyvinyl butyral,
Ethyl cellulose, polyvinyl acetal, polyvinyl acetoacetal, polycarbonate, epoxy resin,
Polyamide etc. can be mentioned. As described above, the leuco dye which is the main component in the thermosensitive coloring layer of the thermosensitive recording material of the present invention,
Specific examples of the color developing agent and the binder resin are given, but these are merely examples and the present invention is not limited to these.
In the present invention, if necessary, known fillers, pigments,
Surfactants and heat-fusible substances can be added. The silicone-modified resin used in the protective layer of the present invention is an organic solvent (toluene, methyl ethyl ketone, alcohols, etc.)
Since it is often used after being dissolved in, the leuco dye and the color developer are dissolved and brought into contact with each other, so that the color is developed immediately after the application. In order to prevent this color development, a leuco dye and / or a developer that are insoluble or slightly soluble in the solvent used are selected and used. The leuco dye and / or the developer are coated with microcapsules to obtain a dye and a developer. It is desirable to adopt a method of making it hard to contact with each other, providing a resin layer on the thermosensitive color developing layer to make it difficult for the dye and the developer to come into contact with each other, and the like. Among these, it is preferable to use the organic phosphoric acid compound represented by the general formula (1) as a developer in terms of fog due to a solvent, color sensitivity, color density and head matching. The heat-sensitive recording layer of the present invention is prepared by uniformly dispersing or dissolving a color former and a developer together with a binder resin in water or an organic solvent, coating this on a support, and drying it. Not limited. When the coating liquid for the recording layer is a dispersion liquid in which a color developer is dispersed, the particle size of the color developer is greatly influenced by the surface roughness of the protective layer, and in fact, the dot reproducibility during printing. It is preferably 5 μm or less. The thickness of the recording layer depends on the composition of the recording layer and the use of the thermal recording medium, but it is about 1 to 50 μm.
It is preferably about 3 to 20 μm. Further, if necessary, various additives commonly used in heat-sensitive recording paper may be added to the recording layer coating liquid for the purpose of improving coatability or recording characteristics. In the present invention, a layer containing a pigment, a binder, a heat-fusible substance or the like can be provided as an intermediate layer between the support and the thermosensitive color-developing layer as required for improving smoothness. . In the present invention, a protective layer is provided in order to improve chemical resistance, water resistance, abrasion resistance, light resistance and head matching with a thermal head. In the present invention, by setting the dynamic friction coefficient of the protective layer surface to 0.4 to 0.8 and the optical surface roughness Rp of the protective layer surface to 0.9 to 1.3 μm, white lines are improved and sticking is prevented. A transparent or semi-transparent heat-sensitive recording material having less dust attached can be obtained.
The protective layer for this purpose is preferably composed of a silicone modified resin and an inorganic filler, and the silicone modified resin and the inorganic filler are preferably contained in an amount of 50% by weight or more based on the total weight of the protective layer. The silicone modified resin used here has a siloxane bond and an alkyl group such as a methyl group bonded to a silicon atom, and has a hydroxyl group, a carboxyl group, an epoxy group, an amino group, a mercapto group or the like at the molecular end or in the molecule. An organopolysiloxane having a reactive functional group is copolymerized with a resin serving as a trunk. Examples of the resin that serves as the trunk include poly (meth) acrylic acid ester resin, polyvinyl butyral resin, polyvinyl acetoacetal resin, ethyl cellulose, methyl cellulose, cellulose acetate, hydroxyethyl cellulose, cellulose acetate propionate, polyurethane resin, polyester resin, and porosity. Thermoplastic of vinyl acetate resin, styrene acrylate resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylamide resin, etc. Resin is used. Therefore, the sliding with the thermal head is good, and since the resin is copolymerized with silicone, dust is unlikely to adhere. The volume average particle size of the inorganic filler used in combination with the silicone modified resin is 0.1 to 0.3 μm, so that the transparency is maintained and the dynamic friction coefficient and the optical surface roughness Rp for eliminating white lines are adjusted. Is effective for. Further, as such an inorganic filler, silica and / or silica coated with calcium is particularly suitable in terms of transparency. Further, the dynamic friction coefficient of the protective layer surface, the optical surface roughness and the transparency of the recording material can be adjusted by the kind, the amount and the ratio of the silicone modified resin and the inorganic filler and the particle diameter of the inorganic filler described above. . The coating method of the protective layer is not particularly limited, and can be applied by a conventionally known method. The thickness of the protective layer is preferably 0.1 to 20 μm, more preferably 0.5 to
It is 10 μm. If the protective layer is too thin, the function of the recording medium as a protective layer such as storability and head matching is insufficient, and if it is too thick, the thermal sensitivity of the recording medium decreases,
It is also disadvantageous in terms of cost. The recording method of the heat-sensitive recording medium of the present invention is not particularly limited in its use mode to a hot pen, a thermal head, laser heating and the like.

[0022]

EXAMPLES The present invention will be described below with reference to examples. In the following, all parts and% are based on weight.

Example 1 The following composition was pulverized and dispersed by a ball mill to a particle size of 0.3 μm to prepare a recording layer coating solution. (Liquid A) 3-diethylamino-6-methyl-7-anilinofluorane 4 parts Octadecylphosphonic acid 12 parts Polyvinyl butyral 6 parts (Denka Butyral # 3000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.) Toluene 57 parts Methyl ethyl ketone 57 parts or more The coating solution prepared as described above was applied onto the polyester film having a thickness of 75 μm (Liquid A) and then dried to form a heat-sensitive recording layer having a thickness of 10 μm. Next, the following composition was pulverized and dispersed by a ball mill to a volume average particle size of 0.2 μm to prepare a dispersion liquid (B liquid) for a protective layer coating liquid. (Liquid B) Silica powder 30 parts (Mizusawa Chemical Co., Mizukasil P-527) Silicon modified polyvinyl butyral resin 24 parts (Nippon Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 146 parts Furthermore, the following composition The product was sufficiently stirred to prepare a protective layer coating liquid. (C liquid) B liquid 44 parts Silicon modified polyvinyl butyral resin 48 parts (Dainichi Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 88 parts The protective layer coating liquid prepared as above is The resulting thermosensitive recording layer was coated and dried to provide a protective layer having a thickness of 3 μm, and the thermosensitive recording medium of the present invention was produced.

Example 2 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. Next, the following composition was pulverized and dispersed by a ball mill to a volume average particle size of 0.15 μm to prepare a dispersion liquid (D liquid) for a protective layer coating liquid. (Liquid D) Calcium-coated silica powder 30 parts (Mizukasi Chemicals, Mizukasil P-832) Silicon modified acrylic resin 10 parts (Toa Gosei, US-350, solid content, 30%) Methyl ethyl ketone 160 parts Further, the following composition The coating liquid for protective layer was prepared by sufficiently stirring. (Solution E) Solution D 44 parts Silicon modified acrylic resin 20 parts (Toagosei, US-350, solid content, 30%) Methyl ethyl ketone 116 parts The protective layer coating solution prepared as described above was obtained in advance. A thermosensitive recording medium of the present invention was prepared by coating the thermosensitive recording layer and drying it to form a protective layer having a thickness of 3 μm.

Example 3 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. The following composition was sufficiently stirred to prepare a protective layer coating liquid (F liquid). (F solution) 10% polyvinyl acetoacetal resin solution 124 parts (Sekisui Chemical's S-REC KS-1, solvent is methyl ethyl ketone) Silicon modified polyvinyl butyral resin 1 part (Dainichi Seika's SP-712, solid content 12.5) %) Methyl ethyl ketone 54 parts The protective layer coating solution prepared as described above is applied onto the thermosensitive recording layer obtained above and dried to provide a protective layer having a thickness of 3 μm, and the thermosensitive recording medium of the present invention is obtained. It was made.

Example 4 A thermosensitive recording layer was formed on a polyester film in the same manner as in Example 1. Next, the following composition was pulverized and dispersed by a ball mill to a volume average particle diameter of 0.25 μm to prepare a dispersion liquid (G liquid) for a protective layer coating liquid. (G liquid) Kaolinite powder 30 parts (Georgia Kaolin, Asia coat HG) Silicon modified polyvinyl butyral resin 24 parts (Dainichi Seika, SP-712, solid content, 12.5%) Methyl ethyl ketone 146 parts Furthermore, the following composition The product was sufficiently stirred to prepare a protective layer coating liquid. (H solution) G solution 44 parts Silicon modified polyvinyl butyral resin 48 parts (Dainichi Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 88 parts The protective layer coating solution prepared as above is The resulting thermosensitive recording layer was coated and dried to provide a protective layer having a thickness of 3 μm, and the thermosensitive recording medium of the present invention was produced.

Comparative Example 1 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. The following composition was sufficiently stirred to prepare a protective layer coating liquid (Liquid I). (Liquid I) Silicon modified polyvinyl butyral resin 50 parts (Dainichi Seika, SP-712, solid content, 12.5%) Methyl ethyl ketone 40 parts The protective layer coating liquid prepared as described above was obtained in advance. A thermosensitive recording medium for comparison was prepared by coating and drying on the thermosensitive recording layer to provide a protective layer having a thickness of 3 μm.

Comparative Example 2 A heat-sensitive recording layer was formed on a polyester film in the same manner as in Example 1. Next, a dispersion liquid (J liquid) for a protective layer coating liquid was prepared in the same manner as the liquid B, except that the inorganic filler pulverized and dispersed to a volume average particle diameter of 0.15 μm was used. Further, the following composition was sufficiently stirred to prepare a protective layer coating liquid. (K solution) J solution 10 parts Silicon modified polyvinyl butyral resin 24 parts (Dainichi Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 30 parts The protective layer coating solution prepared as above is The resulting thermosensitive recording layer was coated and dried to provide a protective layer having a thickness of 3 μm, and the thermosensitive recording medium of the present invention was produced.

Comparative Example 3 In the same manner as in Example 1, a thermosensitive recording layer was formed on the polyester film. Next, a dispersion liquid (L liquid) for a protective layer coating liquid was prepared in the same manner as the liquid B, except that the inorganic filler pulverized and dispersed to a volume average particle diameter of 0.35 μm was used. Further, the following composition was sufficiently stirred to prepare a protective layer coating liquid. (M liquid) L liquid 44 parts Silicon modified polyvinyl butyral resin 24 parts (Dainichi Seika Co., SP-712, solid content, 12.5%) Methyl ethyl ketone 69 parts The protective layer coating liquid prepared as above is A thermosensitive recording medium for comparison was prepared by coating and drying on the thermosensitive recording layer obtained in 1. to provide a protective layer having a thickness of 3 μm.

Comparative Example 4 A thermal recording layer was formed on a polyester film in the same manner as in Example 1. The following composition was sufficiently stirred to prepare a protective layer coating liquid (N liquid). (N liquid) 10% polyvinyl acetoacetal resin solution 124 parts (Sekisui Chemical's S-REC KS-1, solvent is methyl ethyl ketone) Silicon modified polyvinyl butyral resin 0.5 parts (Dainichi Seika's SP-712, solid content, 12) 0.5%) Methyl ethyl ketone 54.5 parts The protective layer coating solution prepared as described above is applied on the heat-sensitive recording layer obtained above and dried to form a protective layer having a thickness of 3 μm, which is used for comparison. A thermal recording medium was prepared. The thermal recording medium produced as described above was evaluated as follows. -Dynamic friction coefficient As described above, it is a value obtained by a ball indenter test using a HEIDON surface property tester under the conditions of a load of 1 kg and a pulling speed of 75 mm / min.・ Optical surface roughness Using a microtopography made by Toyo Seiki Co., Ltd., a pressing force of 13.
It is a value measured under the condition of 5 kgf / cm ² . -Haze degree It is the value measured by JIS-7105.・ White stripe A black solid was printed under the following printing conditions using a thermal printing simulator made by Okura Electric. (Printing conditions) Thermal head dot density: 8 dot / mm Applied power: 0.68 W / dot Pulse width: 0.30 msec Line cycle: 10 msec / line Printing length: 30 cm Printing width: 20 cm Visually, white in the printed image I counted the streaks. -Sticking Printing was performed under the same conditions as in the white line evaluation except that the pulse width was set to 0.50 msec, and the sticking sound between the thermal recording medium and the thermal head during printing was evaluated based on the following criteria. (Reference) ○ ・ ・ ・ Almost no sticking sound △ ・ ・ ・ Slight sticking sound × ・ ・ ・ Sticking sound

[0031]

[Table 1] (Unit) Optical surface roughness: μm Haze degree:% White line: Book

[0032]

As is clear from the above detailed and specific description, the heat-sensitive recording material of the present invention comprises a leuco dye on a transparent or semi-transparent plastic film, a developer capable of heating and coloring the leuco dye, and In a transparent or translucent thermosensitive recording material comprising a thermosensitive coloring layer containing a binder resin as a binder as a main component, and a protective layer formed on the thermosensitive coloring layer, the coefficient of dynamic friction of the protective layer surface is 0.4 to 0. By setting it to 8, white stripes are not generated, sticking property is excellent, dust adhesion is small, and the HAZE degree is low.

Claims (6)

[Claims] 1. A thermosensitive coloring layer mainly comprising a leuco dye, a developer for heating and coloring the leuco dye and a binder resin as a binder on a transparent or translucent plastic film, and a protective layer thereon. In the transparent or semi-transparent heat-sensitive recording material, the coefficient of kinetic friction of the surface of the protective layer is 0.4 to 0.8, and the transparency of the heat-sensitive recording material is a value of 40% or less in the HAZE degree according to JIS7105. A heat-sensitive recording material characterized in that 2. The optical surface roughness Rp of the surface of the protective layer is 0.
The heat-sensitive recording material according to claim 1, which has a thickness of 9 to 1.3 µm. 3. The protective layer comprises a silicone modified resin and an inorganic filler, and the silicone modified resin and the inorganic filler are contained in an amount of 50% by weight or more based on the total weight of the protective layer. 2. The heat-sensitive recording material according to 2. 4. A volume average particle diameter of 0.1 to 0.
The heat-sensitive recording material according to claim 3, which contains an inorganic filler of 3 μm. 5. The heat-sensitive recording material according to claim 4, wherein the inorganic filler in the protective layer is silica and / or calcium-coated silica. 6. The developer according to claim 1, wherein the developer is an organic phosphoric acid compound represented by the following general formula (1).
The heat-sensitive recording material described. [Formula 1] (R ₁ represents a linear alkyl group having 12 to 24 carbon atoms)