JP2020196201A - Thermal recording member and method for manufacturing the same - Google Patents

Abstract

To provide a thermal recording member making it possible to improve printing preserving property.SOLUTION: A thermal recording member 10 is one in which a support 11, a hollow particle layer 12 including hollow particles 2, and a thermal recording layer 14 colored by heating are laminated in this order. The thermal recording member includes a smoothness maintaining layer 13 to maintain smoothness of the hollow particle layer 12 smoothened by a smoothing means, such as super calender. The smoothness maintaining layer is disposed between the hollow particle layer 12 and the thermal recording layer 14 so as to be in contact with the hollow particle layer 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat-sensitive recording member and a method for manufacturing the heat-sensitive recording member.

Conventionally, in various fields such as measurement recorders, terminal printers such as computers, facsimiles, automatic ticket vending machines, and bar code labels, heat-sensitive recording devices using thermal heads have been used for heat-sensitive recording members such as heat-sensitive recording sheets. Therefore, information such as images and characters is recorded.

As the heat-sensitive recording member as described above, generally, a heat-sensitive recording layer containing a color-developing agent or a color-developing agent that develops color by heating is provided on a support such as paper or a plastic film, and the heat-sensitive recording layer is placed on the heat-sensitive recording layer. Those provided with an overcoat layer or the like are widely used.

Further, in recent years, the performance of the heat-sensitive recording device as described above has been improved, the speed is high, the occurrence of faintness is small, and the difference in shade between the printed portion and the non-printed portion is clear and good recording can be performed. It is requested to do so.

Conventionally, in order to meet such demands, an undercoat layer is provided between the support and the thermal recording layer to smooth the surface of the thermal recording layer and improve the adhesion to the thermal head. , Those that improve the sensitivity of the thermal recording member are known. Further, it is also known that by using a hollow particle layer containing hollow particles in the undercoat layer, the heat insulating property is enhanced and the sensitivity of the heat-sensitive recording member is further improved (for example, Patent Document 1). reference).

Further, in order to make the surfaces of the hollow particle layer and the heat-sensitive recording layer smoother, a smoothing means such as a super calendar has been proposed to improve the smoothness and the sensitivity of the heat-sensitive recording member. (See, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2008-80530 Japanese Unexamined Patent Publication No. 64-30785

However, even if the surface of the hollow particle layer is smoothed by applying a calendar, the shape of the hollow particle layer is restored due to the elasticity of the hollow particles contained in the hollow particle layer, and as a result, the smoothness of the hollow particle layer is improved. There is a problem that the print storage stability is deteriorated because of the decrease.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a heat-sensitive recording member and a method for manufacturing a heat-sensitive recording member capable of improving print storage stability.

In order to achieve the above object, the present invention is configured as follows.

(1) The heat-sensitive recording member of the present invention is a heat-sensitive recording member in which a support, a hollow particle layer containing hollow particles, and a heat-sensitive recording layer that develops color by heating are laminated in this order, and the hollow particles. A smoothness maintaining layer for maintaining the smoothness of the hollow particle layer smoothed by the smoothing means is provided between the layer and the heat-sensitive recording layer and in contact with the hollow particle layer.

According to the above configuration, since the smoothness maintaining layer is provided between the hollow particle layer and the heat-sensitive recording layer and in contact with the hollow particle layer, the smoothness of the hollow particle layer is improved by providing smoothing means. In the state, smoothness can be maintained. As a result, the smoothness of the hollow particle layer is improved, so that the smoothness of the upper heat-sensitive recording layer is also improved, and the print storage stability can be improved.

(2) In the heat-sensitive recording member of the present invention, preferably, the smoothing means includes means for smoothing the surface of the hollow particle layer by pressurization. With this configuration, the smoothness of the hollow particle layer can be effectively improved by appropriately crushing the hollow particles contained in the hollow particle layer.

(3) In the heat-sensitive recording member of the present invention, preferably, the smoothness maintaining layer contains a resin having binding property. With this configuration, the smoothness of the hollow particle layer can be maintained by the binding force of the binding resin.

(4) In the heat-sensitive recording member of the present invention, preferably, the smoothness-maintaining layer is made of styrene-butadiene rubber, styrene acrylic, acrylic copolymer, methyl methacrylate, vinylidene chloride, acrylic nitrile, as a resin having binding properties. It contains at least one component selected from the group consisting of acrylic oligomer, acrylic, hydroxyl group urethane, urethane, polyolefin, ethylene vinyl acetate copolymer, polyester, hydroxyethyl cellulose, polyvinyl alcohol, acrylic urethane, polyester urethane. With this configuration, by using the smoothness maintaining layer containing the above components, the smoothness of the hollow particle layer can be maintained more effectively, so that the print storage stability can be effectively improved. it can.

(5) In the heat-sensitive recording member of the present invention, preferably, the smoothness-maintaining layer is made of styrene-butadiene rubber, styrene acrylic, acrylic copolymer, methyl methacrylate, vinylidene chloride, acrylic nitrile, as a resin having binding properties. It contains at least one component selected from the group consisting of acrylic oligomers, acrylics, hydroxyl group urethanes, urethanes, polyolefins, ethylene vinyl acetate copolymers, polyesters, hydroxyethyl celluloses and polyvinyl alcohols (excluding acrylic urethanes and polyester urethanes). With this configuration, by using the smoothness maintaining layer containing the above components, the smoothness of the hollow particle layer can be maintained more effectively, and thus the print storage stability is further improved. Can be made to.

(6) In the heat-sensitive recording member of the present invention, the coating amount of the smoothness maintaining layer is preferably in the range of 0.3 g / m ² or more and 4.0 g / m ² or less. With this configuration, it is possible to obtain a heat-sensitive recording member having excellent print quality.

(7) In the heat-sensitive recording member of the present invention, the coating amount of the smoothness maintaining layer is preferably in the range of 0.4 g / m ² or more and 3.4 g / m ² or less. With this configuration, it is possible to obtain a heat-sensitive recording member having excellent plasticizer resistance (print storage stability) and print quality.

(8) In the heat-sensitive recording member of the present invention, preferably, an overcoat layer is further provided on the surface of the heat-sensitive recording layer opposite to the smoothness maintaining layer. With this configuration, the water resistance, chemical resistance, and plasticizer resistance of the thermal recording layer can be improved, and the printability for the thermal head can be improved so that color development can be performed appropriately. Can be done.

(9) In the method for producing a heat-sensitive recording member of the present invention, a hollow particle layer forming step of forming a hollow particle layer containing hollow particles on a support and a smoothness maintaining layer for maintaining the smoothness of the hollow particle layer are provided. It includes a smoothness-maintaining layer forming step of forming, a smoothing means for smoothing the surface of the hollow particle layer, and a heat-sensitive recording layer forming step of forming a heat-sensitive recording layer on the smoothness-maintaining layer.

According to the above configuration, since a step of forming a smoothness maintaining layer between the hollow particle layer and the heat-sensitive recording layer and in contact with the hollow particle layer is provided, the hollow particle layer is smoothed by providing a smoothing means. Smoothness can be maintained in a state where the degree is improved. As a result, the smoothness of the hollow particle layer is improved, so that the smoothness of the heat-sensitive recording layer formed on the upper layer is also improved, and the print storage stability can be improved.

According to the aspect of the present invention, it is possible to provide a heat-sensitive recording member and a method for manufacturing a heat-sensitive recording member capable of improving print storage stability.

It is the schematic sectional drawing which shows the structure of the heat sensitive recording member which concerns on this embodiment.

Hereinafter, the thermal recording member according to the embodiment of the present invention will be specifically described with reference to the accompanying drawings. The heat-sensitive recording member according to the present invention is not particularly limited to the one shown in the following embodiment, and can be appropriately modified and implemented without changing the gist thereof.

The heat-sensitive recording member 10 according to the present embodiment includes a support 11, a hollow particle layer 12 containing hollow particles 2, a smoothness maintaining layer 13 that maintains the smoothness (smoothness) of the surface of the hollow particle layer 12, and heating. The heat-sensitive recording layer 14 and the overcoat layer 15 that develop color due to the above are laminated in this order to have a structure.

The support 11 is a paper, a non-woven fabric, a plastic film, a metal foil, or a composite sheet in which these are combined.

The hollow particle layer 12 contains a plurality of hollow particles 2 having different particle sizes. As the material of these hollow particles 2, thermoplastic resins such as polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof can be used. it can.

When the hollow particle layer 12 is formed on the support 11, as a step of forming the hollow particle layer, a coating liquid for a hollow particle layer containing the hollow particles 2 and a binder is applied onto the support 11 with a wire. Apply using a coating machine such as a bar, bar coater or rod coater and dry.

As the binder used for the hollow particle layer 12, a commonly used known polymer emulsion or water-soluble polymer can be used. Examples of the polymer emulsion include acrylic-styrene copolymer, styrene-butadiene copolymer, acrylic-butadiene-styrene copolymer, vinyl acetate resin, vinyl acetate-acrylic acid copolymer, and styrene-acrylic acid ester. Emulsions such as copolymers, acrylic acid ester resins, and polyurethane resins can be used.

Examples of the water-soluble polymer include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, and acrylamide-acrylic acid ester copolymers. , Acrylamide-acrylic acid ester-methacrylic acid ternary copolymer, styrene-maleic anhydride copolymer alkali salt, isobutylene-maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. Can be done.

The smoothness maintaining layer 13 is provided between the hollow particle layer 12 and the heat-sensitive recording layer 14 and in contact with the hollow particle layer 12. The smoothness maintaining layer 13 maintains the smoothness of the surface of the hollow particle layer 12 pressurized by a smoothing means such as a super calendar. Specifically, the uneven shape of the surface caused by the shapes of the plurality of hollow particles 2 having different particle sizes contained in the hollow particle layer 12 is smoothed by crushing and deforming the hollow particles 2 with a super calendar. The smoothness maintaining layer 13 suppresses the restoration of the smoothed hollow particle layer 12 to its original shape, and maintains the smoothness of the surface of the hollow particle layer 12.

The smoothness maintaining layer 13 contains a resin having binding properties. Specifically, the smoothness maintaining layer 13 includes styrene acrylic, SBR (styrene butadiene rubber), acrylic copolymer, SBR (containing methyl methacrylate), vinylidene chloride, acrylic nitrile, and acrylic oligomer as resins having binding properties. , Acrylic, hydroxyl group urethane, urethane, polyolefin, EVA (ethylene vinyl acetate copolymer), polyester, hydroxyethyl cellulose, acetoacetyl-modified PVA (polyvinyl alcohol), acrylic urethane, polyester urethane, at least one component selected from the group. Including. By including these components, print storage stability can be effectively improved. Further, those having a more excellent effect from the viewpoint of improving print storage stability are those obtained by removing acrylic urethane and polyester urethane from the above components.

When the smoothness maintenance layer 13 is formed on the hollow particle layer 12, as a step of forming the smoothness maintenance layer, a coating liquid for a smoothness maintenance layer is applied on the hollow particle layer 12, and a wire bar, a bar coater, or a rod coater. Apply using a coating machine such as, and dry it. The coating amount (g / m ² ) of the smoothness maintaining layer 13 is preferably in the range of 0.3 g / m ² or more and 4.0 g / m ² or less, and more preferably 0.4 g / m ² or more and 3.4 g. The range is / m ² or less. When the coating amount (g / m ² ) of the smoothness maintaining layer 13 is 0.3 g / m ² or more and 4.0 g / m ² or less, a heat-sensitive recording member having excellent print quality can be obtained and smoothness is maintained. When the coating amount (g / m ² ) of the layer 13 is 0.4 g / m ² or more and 3.4 g / m ² or less, both print quality and plasticity resistance (print storage stability) are excellent heat sensitivity. A recording member is obtained. The coating amount (g / m ² ) of the smoothness maintenance layer 13 is the mass (g) of the base material before the application of the smoothness maintenance layer coating solution and the sample after the application of the smoothness maintenance layer coating solution. The dry coating amount (g / m ² ) of the coating solution calculated based on the mass (g) of the above and the area (m ² ) of the cross-sectional view trapezoid of the coating solution for the smoothness maintaining layer that has been dried in the dryer. Is.

The heat-sensitive recording layer 14 can include a color former, a color developer, a binder, a sensitizer, a lubricant, a filler, and the like that develop color by heating.

As a color-developing agent that develops color by heating, a commonly used leuco-based dye can be used. Examples of the leuco dye include 3- (N-isobutyl-N-ethyl) amino-6-methyl-7-anilinofluorane and 3- (N-isopentyl-N-ethyl) amino-6-methyl-. 7-o-Chloroanilinofluorane, 3- (N-ethyl-N-p-toluidino) -6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isopentyl) amino-6- Methyl-7-anilinofluorane, 3- (N-ethoxypropyl-N-ethyl) amino-6-methyl-7-anilinofluorane, 3- (N-cyclohexyl-N-methyl) amino-6-methyl -7-anilinofluorane, 3- (N-methyl-Nn-propyl) amino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3-Diethylamino-6-methyl-7-p-toluidinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-8-methylfluorane, 3-diethylamino -7- (m-trifluoromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7-chlorofluorane, 3-dibutylamino-6-methyl-7-bromofur Oran, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-dimethylamino-5-methyl-7-methylfluorane, 3-pyrrolidino -6-Methyl-7-anilinofluorane, crystal violet lactone, etc. can be used alone or in combination of two or more.

Further, as the color developer, various electron-accepting substances that react with the above-mentioned leuco dye at the time of heating to develop a color can be used. Examples of the color developer include 1,1-bis (p-hydroxyphenyl) cyclohexane, 1,1-bis (p-hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) propane, 2, 2-Bis (p-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2'-methylenebis (4-chlorophenol), 2,2-bis (4-hydroxy) Phenyl) -4-methylpentane, 2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 4-hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone , 4-Hydroxy-4'-methyldiphenyl sulfone, 4-hydroxyphenyl-4'-benzyloxyphenyl sulfone, 4-hydroxy-4'-allyloxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, Poly (4-hydroxybenzoic acid), benzyl 4-hydroxybenzoate, 2,4-bis (phenylsulfonyl) phenol, α- {4-[(4-hydroxyphenyl) sulfonyl] phenyl} -ω-hydroxypoly (polymerization) Degree n = 1-7) (Oxyethyleneoxyethyleneoxy-p-phenylenesulfonyl-p-phenylene) 2,2-bis [(4-methyl-3-phenoxycarbonylaminophenyl) urea] diphenylsulfone, 3,5- Bis (α-methylbenzyl) salicylic acid, bis [4- (n-octyloxycarbonylamino) zinc salicylate], 4,4'-bis (p-tolylsulfonylaminocarbonylamino) diphenylmethane, 4-hydroxybenzenesulfonanilide, 2 '-(3-Phenylureide) benzenesulfonanilide, N- (2-hydroxyphenyl) -2-[(4-hydroxyphenyl) thio] acetamide, N- (4-hydroxyphenyl) -2-[(4-hydroxy) Phenyl) thio] acetamide, 4-[[4- [4- [4- [[4- (1-methylethoxy) phenyl] sulfonylphenoxy] butoxy] phenyl] sulfonyl] phenol, 4-tert-butylphenol / formaldehyde polycondensation It is possible to use a substance, N- (p-toluenesulfonyl) N'-(3-p-toluenesulfonyloxyphenyl) urea, 1-phenyl-3- (4-methylphenylsulfonyl) urea, etc. Wear.

Further, as the binder for the heat-sensitive recording layer 14, a commonly used and known binder can be used. Examples of the binder include polyvinyl alcohol, modified polyvinyl alcohol, starch, casein, gelatin, polyamide, polyacrylamide, modified polyacrylamide, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl acetate, and polyacrylic acid. Estel, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, diisobutylene-maleic anhydride copolymer, vinyl acetate-maleic anhydride copolymer, methylvinyl-maleic anhydride copolymer, Isopropylene-maleic anhydride copolymer, styrene-butadiene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, polyurethane, polystyrene, polyvinylpyrrolidone, acrylic acid ester, acrylic nitrile, methyl vinyl ether , Can be used alone or in combination of two or more.

Further, as the sensitizer, lubricant, filler and the like included in the heat-sensitive recording layer 14, commonly used known ones can be used. Examples of the sensitizer include stearic acid, stearic acid amide, stearic acid anilide, methylol stearate amide, methylene bisstearic acid amide, ethylene bisstearic acid amide, 1-benzyloxynaphthalene, and 2-benzyloxynaphthalene. 2,6-diisopropylnaphthalene, 1,2-diphenoxyethane, 1,2-diphenoxymethylbenzene, 1,2-bis (3,4-dimethylphenol) ethane, 1,2-bis (3-methylphenoxy) ) Etan, 1,2-bis (4-methylphenoxy) ethane, di (p-chlorobenzyl) oxalate, di (p-methylbenzyl) oxalate, dibenzyl oxalate, p-benzylbiphenyl, m-terphenyl, Diphenylsulfone, benzyl p-benzyloxybenzoate, dibenzyl terephthalate, p-toluenesulfonamide, etc., which are solid at room temperature, preferably having a melting point of about 70 ° C. or higher can be used. Examples of lubricants include fatty acids such as paraffin wax and oleic acid, polyolefin waxes such as polyethylene wax, metal soaps such as zinc stearate, ester waxes such as carnauba wax, and oils such as silicon oil and whale oil. Can be used alone or in combination of two or more. Examples of the filler include aluminum hydroxide, magnesium hydroxide, aluminum oxide, magnesium oxide, aluminum silicate, calcium carbonate, magnesium carbonate, titanium oxide, barium sulfate, silica gel, active white clay, talc, clay, kaolin, and the like. Calcined kaolin, silicate soil, white carbon, zinc oxide, silicon oxide, colloidal silica gel, polystyrene resin particles, urea-formalin resin particles, polyolefin resin particles, etc. can be used alone or in combination of two or more.

When the heat-sensitive recording layer 14 is formed on the smoothness-maintaining layer 13, as a heat-sensitive recording layer forming step, a coating liquid for the heat-sensitive recording layer is manually applied on the smoothness-maintaining layer 13 using a wire bar. , Bar coater, rod coater, curtain coater, gravure coater, lip coater, comma coater, etc., and dry.

The overcoat layer 15 has a structure in which a first overcoat layer 15a formed on the heat-sensitive recording layer 14 and a second overcoat layer 15b formed on the first overcoat layer 15a are laminated. The overcoat layer 15 is not limited to a structure in which the first overcoat layer 15a and the second overcoat layer 15b are laminated, and may be a single layer.

When the overcoat layer 15 is formed on the heat-sensitive recording layer 14, the coating liquid for the overcoat layer is applied on the heat-sensitive recording layer 14 by hand using a wire bar, a bar coater, a rod coater, a curtain coater, or the like. Apply using a coating machine such as a gravure coater, lip coater, or comma coater, and dry this.

The first overcoat layer 15a is mainly for improving the water resistance, chemical resistance, plasticizing agent resistance, etc. of the heat sensitive recording layer 14, and examples of the binder include polyvinyl alcohol and modified polyvinyl alcohol. , Stheat, Modified Steel, Casein, Gelatin, Kawa, Rubber Arabia, Polyamyl, Polyacrylamide, Modified Polyacrylamide, Hydroxyethyl Cellulose, Methyl Cellulose, Carboxymethyl Cellulose, Hydroxypropyl Cellulose, Polyacetic Acid Vinyl, Polyacrylic Acid Ester, Styrene-Maleic anhydride Copolymer, Isobutylene-maleic anhydride copolymer, diisobutylene-maleic anhydride copolymer, vinyl acetate-maleic anhydride copolymer, methylvinyl-maleic anhydride copolymer, isopropylene-maleic anhydride copolymer Polymers, styrene-butadiene copolymers, maleic acid copolymers, polyvinyl chlorides, polyvinylidene chlorides, vinyl chloride-vinyl acetate copolymers, polyurethanes, polystyrenes, polyvinylpyrrolidones, acrylic acid esters, acrylonitrile, methyl vinyl ethers, etc. Aqueous resins can be used alone or in combination of two or more.

The second overcoat layer 15b is mainly for improving the matching property of the heat-sensitive recording layer 14 with respect to the thermal head so that the color development in the heat-sensitive recording layer 14 can be appropriately performed, and is filled in the binder. Additives such as lubricants, crosslinkers, dispersants, defoamers, and water resistant agents are added as needed.

Examples of the binder for the second overcoat layer 15b include polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl butyral, polyvinylpyrrolidone; polyvinylcarbazole; starches; cellulose derivatives; alginates; acrylic acid esters, polyacrylamides, and polymethylmethacrylates. , Polybutylmethacrylate and other acrylic resins; alkyd resin; maleic acid resin; acrylonitrile resin; epoxy resin; polyester resin; polyamide resin; styrene resin; urethane resin; vinylidene resin and the like can be used alone or in combination of two or more.

Fillers include, for example, aluminum hydroxide, aluminum oxide, aluminum silicate, heavy calcium carbonate, light calcium carbonate, titanium oxide, barium sulfate, silica gel, active white clay, talc, clay, kaolinite, caiso soil, and white carbon. , Magnesium carbonate, magnesium oxide, magnesium hydroxide, zinc oxide, polystyrene resin particles, urea-formalin resin particles, polyolefin resin particles and the like can be used alone or in combination of two or more.

According to the present embodiment described above, the following effects can be obtained.

(1) The heat-sensitive recording member 10 according to the above embodiment is a heat-sensitive recording member 10 in which a support 11, a hollow particle layer 12 containing hollow particles 2, and a heat-sensitive recording layer 14 that develops color by heating are laminated in this order. The smoothness of the hollow particle layer 12 that has been smoothed by a smoothing means such as a super calendar so as to be between the hollow particle layer 12 and the heat-sensitive recording layer 14 and in contact with the hollow particle layer 12 is maintained. The degree maintenance layer 13 is provided.

According to the above configuration, since the smoothness maintaining layer 13 is provided between the hollow particle layer 12 and the heat-sensitive recording layer 14 and in contact with the hollow particle layer 12, the smoothness of the hollow particle layer 12 is provided by applying a super calendar. The smoothness can be maintained in the state where the above is improved. As a result, the smoothness of the hollow particle layer 12 is improved, so that the smoothness of the heat-sensitive recording layer 14 of the upper layer is also improved, and the print storage stability can be improved.

(2) In the heat-sensitive recording member 10 according to the above embodiment, the hollow particles 2 contained in the hollow particle layer 12 are appropriately crushed by using a super calendar that smoothes the surface of the hollow particle layer 12 by pressurization. , The smoothness of the hollow particle layer 12 can be effectively improved.

(3) In the heat-sensitive recording member 10 according to the above embodiment, by using the smoothness maintaining layer 13 containing styrene acrylic as the resin having binding property, the smoothness of the hollow particle layer 12 is further improved by the binding force of styrene acrylic. Since it can be maintained effectively, the print storage stability can be improved more effectively.

(4) In the heat-sensitive recording member 10 according to the above embodiment, the coating amount of the smoothness maintaining layer 13 is set in the range of 0.3 g / m ² or more and 4.0 g / m ² or less, so that the heat-sensitive printing quality is excellent. The recording member 10 can be obtained.

(5) In the heat-sensitive recording member 10 according to the above embodiment, the coating amount of the smoothness maintaining layer 13 is set in the range of 0.4 g / m ² or more and 3.4 g / m ² or less to have plasticizer resistance (printing). It is possible to obtain a heat-sensitive recording member 10 having excellent storage stability) and print quality.

(6) In the heat-sensitive recording member 10 according to the above embodiment, the heat-sensitive recording layer 14 is further provided with an overcoat layer 15 on the surface opposite to the smoothness maintaining layer 13, so that the heat-sensitive recording layer 14 is water-resistant and chemical-resistant. The properties and plasticizer resistance can be improved, and the printability for the thermal head can be improved so that the color can be appropriately developed.

(7) The method for manufacturing the heat-sensitive recording member 10 according to the above embodiment maintains the hollow particle layer forming step of forming the hollow particle layer 12 containing the hollow particles 2 on the support 11 and the smoothness of the hollow particle layer 12. A step of forming a smoothness maintaining layer 13 for forming a smoothness maintaining layer 13, a smoothing means for smoothing the surface of a hollow particle layer 12, and forming a heat sensitive recording layer 14 for forming a heat sensitive recording layer 14 on the smoothness maintaining layer 13. It has a process.

According to the above configuration, in order to include a step of forming the smoothness maintaining layer 13 between the hollow particle layer 12 and the heat-sensitive recording layer 14 and in contact with the hollow particle layer 12, a smoothing means such as a super calendar is provided. Therefore, the smoothness can be maintained in a state where the smoothness of the hollow particle layer 12 is improved. As a result, the smoothness of the hollow particle layer 12 is improved, so that the smoothness of the heat-sensitive recording layer 14 formed on the upper layer is also improved, and the print storage stability can be improved.

Next, an example to which the heat-sensitive recording member according to the present invention is applied will be described.

(Example 1)
Smoothness of a coating amount of 0.3 g / m ² containing a coating liquid for a hollow particle layer containing hollow particles and styrene acrylic as a resin (main component) having binding properties on one surface of high-quality paper as a support. The coating liquid for the maintenance layer was sequentially applied and dried using a wire bar to form a hollow particle layer and a smoothness maintenance layer. Then, the smoothness maintaining layer surface was subjected to super calendar processing. Next, 3-diethylamino-6-methyl-7-anilinofluorane as a dye, 4-hydroxy-4'-N-propoxydiphenyl sulfone as a developer, and calcined kaolin as a filler were dispersed in a dispersion medium. After that, a coating liquid for a heat-sensitive recording layer having a coating amount of 4.0 g / m ² prepared by adding a styrene-butadiene copolymer as a binder and at least one of paraffin wax and polyethylene wax as a lubricant was maintained in smoothness. A heat-sensitive recording layer was formed by applying and drying on the layer using a wire bar. Next, on the heat-sensitive recording layer, a coating liquid for an overcoat layer containing an acrylic resin as a main component and having a coating amount of 1.0 g / m ² was applied and dried using a wire bar to form an overcoat layer. , A heat-sensitive recording member was obtained.

(Plasticizer resistance evaluation and print storage stability evaluation)
The thermal recording member having the above-described configuration was cut into a width of 4 cm. The cut heat-sensitive recording member was humidity-controlled for 2 hours in a constant temperature and humidity chamber (23%, 50% RH). A checkerboard pattern was printed on the heat-sensitive recording member after humidity control using a label printer, and the color density was measured with an X-rite eXact densitometer. This measured value was used as the color development density before the test, and as a plasticizer resistance test, four vinyl chloride films were laminated on a PET film and attached with a rubber roller. The separator of the heat-sensitive recording member was peeled off and attached to a PVC film that was in close contact with the material. The cut vinyl chloride film and the PET film were brought into close contact with each other in this order with a rubber roller. A load of 300 g / cm ² was applied to the heat-sensitive recording member, and the member was left at 40 ° C. for 15 hours. Then the sample was taken out. The residual color density (= (color density after test / color density before test) x 100), which is the ratio of the color density after the test (plasticizer resistance 40 ° C., after 15 hours) to the color density before the test. Calculated. This result is shown in the plasticizer resistance (residual rate) in Table 1. Then, those having a plasticizer resistance (residual rate) of 70% or more are regarded as good storage stability (○), and those having a plasticizer resistance (residual rate) of 69% or less and 40% or more are regarded as good storage stability (Δ). , Plasticizer resistance (residual rate) of 39% or less was shown as poor storage stability (x). The results are shown in Table 1.

(Print quality evaluation)
A heat-sensitive recording member cut to a width of 6 cm was colored with a measuring label printer (trade name: ISHIDA IP-UNI-F), and the white spots in the colored part were visually evaluated, and almost no white spots occurred. The quality was good (◯), and the one in which white spots were relatively generated was regarded as good quality (Δ), and the results are shown in the print quality of the table. The results are shown in Table 1.

(Example 2)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 0.4 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 3)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 0.5 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 4)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 1.0 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 5)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 2.1 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 6)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 3.1 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 7)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was set to 3.4 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Example 8)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the amount of the coating liquid for the smoothness maintaining layer was 4.0 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the smoothness maintenance layer was not provided (formed). The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

The heat-sensitive recording member in Example 1 had good plasticizer resistance (print storage stability) and good print quality. Further, the heat-sensitive recording members in Examples 2 to 7 had good plasticizer resistance (print storage stability) and print quality. Further, the heat-sensitive recording member in Example 8 had good plasticizer resistance (print storage stability) and good print quality. On the other hand, the heat-sensitive recording member in Comparative Example 1 had poor plasticizer resistance (print storage stability) and was good in print quality. That is, when the main component of the smoothness maintaining layer of the heat-sensitive recording member is styrene acrylic and the coating amount is in the range of 0.4 g / m ² or more and 3.4 g / m ² or less, it will be described in Examples 2 to 7. As described above, it can be said that the print storage stability is good and the print quality is also good. Further, when the main component of the smoothness maintaining layer of the heat-sensitive recording member is styrene acrylic and the coating amount is in the range of 0.3 g / m ² or more and 4.0 g / m ² or less, as described in Example 1. It can be said that the print storage stability is good and the print quality is good, and as described in Examples 2 to 7, both the print storage stability and the print quality are good, and in Example 8. As described above, it can be said that the print storage stability is good and the print quality is good.

(Example 9)
The heat-sensitive recording member is the same as in Example 1 except that the main component of the smoothness maintenance layer is SBR (styrene butadiene rubber) and the amount of the coating liquid for the smoothness maintenance layer is 1.9 g / m ^2. Was produced. The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 10)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness maintaining layer was an acrylic copolymer and the coating amount for the smoothness maintaining layer was 1.9 g / m ^2. did. The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 11)
The heat-sensitive recording member was the same as in Example 1 except that the main component of the smoothness-maintaining layer was SBR (containing methyl methacrylate) and the amount of the coating liquid for the smoothness-maintaining layer was 2.2 g / m ^2. Was produced. The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 12)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was vinylidene chloride and the amount of the coating liquid for the smoothness-maintaining layer was 2.1 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 13)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness maintaining layer was acrylonitrile and the amount of the coating liquid for the smoothness maintaining layer was 2.4 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 14)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness maintaining layer was an acrylic oligomer and the amount of the coating liquid for the smoothness maintaining layer was 2.2 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 15)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was acrylic and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 16)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness maintenance layer was hydroxyl group urethane and the coating amount of the smoothness maintenance layer coating liquid was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 17)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness maintaining layer was urethane and the amount of the coating liquid for the smoothness maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 18)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was polyolefin and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 19)
Thermal recording was performed in the same manner as in Example 1 except that the main component of the smoothness maintaining layer was EVA (ethylene vinyl acetate copolymer) and the amount of the coating liquid for the smoothness maintaining layer was 1.9 g / m ^2. A member was produced. The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 20)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was polyester and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 21)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was hydroxyethyl cellulose and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 22)
Heat-sensitive in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was acetoacetyl-modified PVA (polyvinyl alcohol) and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ^2. A recording member was produced. The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 23)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was acrylic urethane and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

(Example 24)
A heat-sensitive recording member was produced in the same manner as in Example 1 except that the main component of the smoothness-maintaining layer was polyester urethane and the amount of the coating liquid for the smoothness-maintaining layer was 1.9 g / m ² . The obtained heat-sensitive recording member was subjected to the same evaluation as in Example 1. The results are shown in Table 2.

The plasticizer resistance (print storage stability) of the heat-sensitive recording member in Examples 9 to 22 of the present invention was good. On the other hand, the plasticizer resistance (print storage stability) of the heat-sensitive recording member in Examples 23 and 24 was good. That is, as described in Examples 9 to 22, SBR, an acrylic copolymer, SBR (containing methyl methacrylate), vinylidene chloride, acrylic nitrile, as a resin having binding property to the smoothness maintaining layer of the heat-sensitive recording member, When it contains at least one component selected from the group consisting of acrylic oligomer, acrylic, hydroxyl group urethane, urethane, polyolefin, EVA, polyester, hydroxyethyl cellulose, and acetoacetyl-modified PVA, it is said that the print storage property is good. I can say. On the other hand, as described in Examples 23 and 24, the resin having binding property to the smoothness maintaining layer of the heat-sensitive recording member contains at least one component selected from the group consisting of acrylic urethane and polyester urethane. In that case, it can be said that the print storage stability is good.

Moreover, the print quality of the heat-sensitive recording member in Examples 9 to 15, 18 to 22 and 24 was good. On the other hand, the print quality of the heat-sensitive recording member in Examples 16, 17 and 23 was good. That is, as described in Examples 9 to 15, 18 to 22 and 24, SBR, an acrylic copolymer, SBR (containing methyl methacrylate), as a resin having binding property to the smoothness maintaining layer of the heat-sensitive recording member, Good print quality when it contains at least one component selected from the group consisting of vinylidene chloride, acrylic nitrile, acrylic oligomers, acrylic, polyolefin, EVA, polyester, hydroxyethyl cellulose, acetoacetyl-modified PVA, and polyester urethane. You can say that. On the other hand, as described in Examples 16, 17 and 23, at least one selected from the group consisting of hydroxyl group urethane, urethane, and acrylic urethane as the resin having binding property to the smoothness maintaining layer of the heat sensitive recording member. When two components are contained, it can be said that the print quality is good.

The above embodiment may have a modified configuration as follows.

-In the above embodiment, an example is shown in which the smoothness maintaining layer of the present invention contains a resin having binding properties, but the present invention is not limited to this. In the present invention, if it is possible to maintain the smoothness of the hollow particle layer, it is not necessary to include a resin having binding property.

-In the above embodiment, the smoothness maintaining layer of the present invention has styrene acrylic, SBR, acrylic copolymer, SBR (containing methyl methacrylate), vinylidene chloride, acrylic nitrile, acrylic oligomer, acrylic as a resin having binding properties. , Acrylic urethane, urethane, polyolefin, EVA, polyester, hydroxyethyl cellulose, acetoacetyl-modified PVA, acrylic urethane, polyester urethane, an example containing at least one component selected from the group is shown. Not limited. In the present invention, if the resin has a binding property, the same result can be obtained by including a resin having a binding property other than the above in the smoothness maintaining layer. Further, two or more kinds of resins having the above-mentioned binding property may be contained.

-In the above embodiment, an example of using a super calendar as an example of the smoothing means of the present invention is shown, but the present invention is not limited to this. In the present invention, if it is possible to smooth the surface of the hollow particle layer, a smoothing means other than the super calendar can be used.

-The above embodiments are all examples of the indications of the present invention, and it is natural that any other embodiment within the scope of the claims is included in the technical scope of the invention.

2 ... Hollow particles 10 ... Thermal recording member 11 ... Support 12 ... Hollow particle layer 13 ... Smoothness maintenance layer 14 ... Thermal recording layer 15 ... Overcoat layer

Claims (9)

A heat-sensitive recording member in which a support, a hollow particle layer containing hollow particles, and a heat-sensitive recording layer that develops color by heating are laminated in this order.
Thermal recording provided with a smoothness maintaining layer that maintains the smoothness of the hollow particle layer smoothed by smoothing means so as to be between the hollow particle layer and the heat sensitive recording layer and in contact with the hollow particle layer. Element. The heat-sensitive recording member according to claim 1, wherein the smoothing means includes means for smoothing the surface of the hollow particle layer by pressurization. The heat-sensitive recording member according to claim 1 or 2, wherein the smoothness maintaining layer contains a resin having binding properties. The smoothness-maintaining layer includes styrene acrylic, SBR, acrylic copolymer, SBR (containing methyl methacrylate), vinylidene chloride, acrylic nitrile, acrylic oligomer, acrylic, hydroxyl group urethane, urethane, polyolefin, as a resin having binding properties. The heat-sensitive recording member according to claim 3, which comprises at least one component selected from the group consisting of EVA, polyester, hydroxyethyl cellulose, acetoacetyl-modified PVA, acrylic urethane, and polyester urethane. The smoothness-maintaining layer includes styrene acrylic, SBR, acrylic copolymer, SBR (containing methyl methacrylate), vinylidene chloride, acrylic nitrile, acrylic oligomer, acrylic, hydroxyl group urethane, urethane, polyolefin, as a resin having binding properties. The heat-sensitive recording member according to claim 3, which comprises at least one component selected from the group consisting of EVA, polyester, hydroxyethyl cellulose, and acetoacetyl-modified PVA (excluding acrylic urethane and polyester urethane). The heat-sensitive recording member according to any one of claims 1 to 5, wherein the coating amount of the smoothness maintaining layer is in the range of 0.3 g / m ² or more and 4.0 g / m ² or less. The heat-sensitive recording member according to claim 6, wherein the coating amount of the smoothness maintaining layer is in the range of 0.4 g / m ² or more and 3.4 g / m ² or less. The heat-sensitive recording member according to any one of claims 1 to 7, further comprising an overcoat layer on a surface of the heat-sensitive recording layer opposite to the smoothness maintaining layer. A hollow particle layer forming step of forming a hollow particle layer containing hollow particles on a support, and
A step of forming a smoothness maintenance layer for forming a smoothness maintenance layer for maintaining the smoothness of the hollow particle layer,
A smoothing means for smoothing the surface of the hollow particle layer,
A method for manufacturing a heat-sensitive recording member, comprising a heat-sensitive recording layer forming step of forming a heat-sensitive recording layer on the smoothness maintaining layer.

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