JPH0550750A - Thermosensitive recording material - Google Patents

Abstract

PURPOSE:To keep secret until an opaque sheet or an extension part of a base sheet is peeled after printing by covering the surface of a thermosensitive record ing material layer with the opaque sheet or the extension part of the base sheet in a thermosensitive recording material in which the thermosensitive recording material layer is formed on the base sheet processed to be opaque. CONSTITUTION:A thermosensitive recording material layer 2 of this thermosensitive recording material is provided on one surface of a base sheet 1 which is processed to be opaque. The recording material is bonded to an opaque sheet 3 in the peripheral part thereof in a manner to cover the surface of the thermosensitive recording material layer. Or, a thermosensitive recording material layer 2 of this thermosensitive recording material is provided of a base sheet 1 which is processed to be opaque, and an extension part 4 of the base sheet l is folded to cover the surface of the thermosensitive recording material layer. The thermosensitive recording material is bonded with the folded extension part of the base sheet in the peripheral part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material for the purpose of keeping confidential output contents when an output terminal such as a facsimile is used.

[0002]

2. Description of the Related Art In recent years, many output terminals have been sold due to the development of computers and communication equipment, and the recording materials used for them have been dramatically increased. Particularly in the field of facsimile, a device using a thermosensitive coloring paper in which a thermosensitive coloring material is carried on a base sheet is widely used. On the other hand, demand for plain paper recording is also high, and an apparatus using a thermal transfer sheet for transferring a coloring material carried on a base material sheet to a recording material by a heating means such as a thermal head or a laser is also widely used.

[0003]

[Problems to be solved by the invention] However,
Documents and drawings output by such a facsimile device and other output terminals have no particular consideration regarding confidentiality, and can be viewed freely by anyone other than the recipient.
In addition, the facsimile service network that uses the post office, the so-called retax service, is for the received paper to be bagged and delivered by the post office staff, but the received contents are not kept confidential until bagged. However, it is troublesome to pack the bag. Therefore, the object of the present invention is to solve the above problems,
It is to provide a heat-sensitive recording material excellent in keeping confidentiality.

[0004]

The above object can be achieved by the present invention described below. That is, the present invention is a heat-sensitive recording material provided with a heat-sensitive recording material layer on an opaque substrate sheet,
The heat-sensitive recording material is characterized in that an opaque sheet or an extension portion of the base material sheet is adhered in the peripheral portion so as to cover the surface of the heat-sensitive recording material layer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to preferred embodiments in terms of constitution. FIG. 1 schematically shows a heat-sensitive recording material in which a heat-sensitive recording material layer 2 is provided on one surface of an opaque-treated base sheet 1, and an opaque sheet 3 is the heat-sensitive recording material layer surface. To cover
The heat-sensitive recording material of the present invention is characterized in that it is adhered at its peripheral portion. FIG. 2 schematically shows a heat-sensitive recording material in which a heat-sensitive recording material layer 2 is provided on a base material sheet 1 that has been subjected to an opaque treatment, and the extension 4 of the base material sheet is a heat-sensitive recording material. The heat-sensitive recording material of the present invention is characterized in that a base sheet extension which is folded back so as to cover a layer surface and is folded back with the heat-sensitive recording material is adhered to the peripheral portion thereof. Here, the sticking may be carried out via an adhesive or a pressure-sensitive adhesive, or depending on the material of the base sheet and the opaque sheet, the sticking portions of the base sheet and the opaque sheet or the base sheet The pasted portions of the folded back extension portions may be pasted together by means such as heat sealing.

FIG. 5 shows the state of heat generation when the thermosensitive recording material layer is a thermosensitive coloring material layer mainly composed of a color former, a color developer and a binder. Unlike ordinary thermosensitive coloring paper, heat printing is performed from the side opposite to the thermosensitive coloring material layer side of the substrate sheet by a thermal head, laser, etc., so it is necessary to correct the output so as to obtain a mirror image.
FIG. 6 shows a transfer state when the heat-sensitive recording material layer is a heat-sensitive transfer material layer. The heat-sensitive transfer material which is transferred by a heating means such as a thermal head or a laser may be mainly composed of a colored pigment and a pigment binder, or may be mainly composed of a dye and a dye binder. Opaque sheet 3 and folded base sheet extension 4
If the surface contacting the heat-sensitive transfer material layer is a material that receives the transfer material, there is no particular problem, but if not, a transfer material receiving layer 10 is provided as shown in FIG. Is preferably treated.

The opaque-treated base sheet 1 and its extension 4 and opaque sheet 3 are originally opaque themselves, such as papers, those into which pigments such as carbon are mixed at the time of forming the sheet, and the sheet. With a hiding layer on top,
A composite sheet in which a concealing layer is provided as an intermediate layer, a sheet which is made opaque by a physical treatment such as roughening the sheet, and the like are conceivable, but it is not particularly limited as long as it is opaque.

As shown in FIG. 1, FIG. 2 or FIG. 4, it is preferable to provide a heat resistant slipping layer 8 on the side of the substrate sheet which comes into contact with the thermal head for the purpose of preventing sticking. When recording is carried out by a laser system, it is necessary to provide the light absorbing layer 9 on at least the base material sheet in the region where the laser light hits the thermal recording material layer portion. This layer may be applied and formed on the surface of the base material sheet as shown in FIG. 3, or may be provided as an intermediate layer of the composite sheet (not shown), and further, a pigment or the like may be added to the base material itself. May be mixed and the base material sheet itself may be used as a light absorbing layer (not shown). Further, a light absorption heating element may be mixed in the heat-sensitive recording material layer (not shown). The light absorption layer can also function as a masking layer.

FIGS. 7 to 10 show the opaque sheet 3 and the extended portion 4 of the folded back substrate sheet, and the heat-sensitive recording material can be applied to a portion other than the area covered with the heat-sensitive recording material layer 2. FIG. 3 is a diagram showing an embodiment in which a recording material layer 7 is provided.
According to this, confidential contents can be selectively output to the covered area, and other information that may be viewed can be selectively output to areas other than the covered area.

Next, the present invention will be described in more detail with reference to preferred embodiments in terms of materials. As the base material sheet 1 of the heat-sensitive recording material, the same base material sheet as that used in the conventional heat-sensitive transfer material can be used as it is, and other materials can also be used and are not particularly limited.
Specific examples of preferable substrate sheet include, for example, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride,
Polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber,
There are plastics such as ionomers, papers such as condenser papers and paraffin papers, non-woven fabrics and the like, and a base material sheet in which these are compounded may be used. The thickness of this substrate sheet can be appropriately changed depending on the material so that its strength and thermal conductivity are appropriate, but preferably 2 to 25.
μm.

The thermosensitive coloring material layer is mainly composed of a coloring agent, a color developing agent and a binder, which are dissolved in an appropriate organic solvent or dispersed in an organic solvent or water, for example, a gravure printing method. It is formed by applying and drying by a forming means such as a screen printing method and a reverse roll coating method using a gravure plate. The heat-sensitive coloring material layer formed as described above may have any thickness, but it is generally suitable to apply it so as to be 1 to 10 g / m ² when dried.

As the color-developing agent, those used in this type of heat-sensitive color-developing material are arbitrarily selected and used alone or in admixture of two or more. For example, triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based leuco dyes and the like can be mentioned, but the leuco dyes are not particularly limited, and conventionally known dyes can be freely used.

Known color developers can be used, but the following are preferred. Benzoic acid, salicylic acid, 3,5-xylenol, thymol, p-tert-butylphenol, 4-hydroxyphenoxide, methyl-4-hydroxyacetophenone, α-naphthol, β-naphthol, catechol,
Resorcin, hydroquinone, 4-tert-octylcatechol, 4,4′-sec-butylidenephenol,
2,2-dihydroxydiphenyl, 2,2-methylenebis (4-methyl-6-tert-butylphenol),
2,2'-bis (4'-hydroxyphenylpropane), 4,4'-isopropylidene-bis (2-ter
t-butylphenol), 4,4′-sec-butylidene diphenol, pyrogallol, phloroglucin and the like.

As the binder, known binders can be used, but specific examples include the following. Casein, polyvinyl alcohol, carboxymethyl cellulose, sodium alginate, methyl cellulose, hydroxyethyl cellulose, polyvinyl pyrrolidone, polyacrylic amide, polyvinyl acetate, polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylic ester, vinyl chloride / vinyl acetate Copolymer, polybutylmethacrylate, ethylene / vinyl acetate copolymer,
Styrene / butadiene / acrylic copolymers and the like.

As the heat-sensitive transfer material layer, a hot-melt ink layer mainly composed of a pigment and a pigment binder and a heat sublimation ink layer mainly composed of a dye and a dye binder can be considered. As a pigment,
Any of the conventionally known ones can be used, and specific examples thereof include carbon black, Gunjou, cadmium yellow, red iron oxide, chrome yellow, lead white and titanium white. The binder resin for supporting the pigment as described above,
Any conventionally known one can be used. As a preferable example, a mixture containing wax as a main component and other wax and a drying oil, a resin, a mineral oil, a derivative of cellulose and rubber, or the like is used. Typical examples of waxes include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax, ivowa wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified wax, fatty acid ester,
Various waxes such as fatty acid amide are used. In the present invention, a thermoplastic resin having a relatively low melting point can be further mixed in the wax to improve the adhesion of the ink to the transfer material. As a method for forming a hot-melt ink layer on a substrate sheet, necessary components such as a pigment and a binder containing a wax as a main component are melt-kneaded, and this is coated by a hot-melt coating method or the above wax. Examples thereof include a method of applying and drying an emulsion ink obtained by mixing an emulsion in which an aqueous binder, which is a main component, may be emulsified or dispersed in an aqueous medium that may contain alcohol, and an emulsion ink. As the binder, it is preferable to use a thermoplastic resin in addition to the wax, and the thermoplastic resin is 10 to 100 parts by weight of the wax.
It is preferably used in a proportion of 100 parts by weight. The ink layer thus formed is usually preferably formed to have a thickness of about 2 to 20 μm.

Any conventionally known dye can be used as the dye. Specifically, as the red dye, MS Red can be used.
G, Macrolex Red VioletR, C
eresRed7B, Samaron Red HBS
L, Resolin Red F3BS, etc., as a yellow dye, Holon Brilliant Yellow 6GL, PTY-5
2, such as Macrolex Yellow 6G, as the blue dye, Kayaset Blue 714, Waxolin Blue AP-FW, Holon Brilliant Blue SR, MS
Blue 100 etc. Any conventionally known binder resin can be used as the binder resin for supporting the dye as described above. Preferred examples include ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose resins such as cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, Examples include vinyl resins such as polyacrylamide, polyester, etc.
Acetal-based, butyral-based, polyester-based, and the like are preferable from the viewpoint of heat resistance, dye migration, and the like. Further, the heat sublimation ink layer may also contain various conventionally known additives, if necessary. Such a thermal sublimation ink layer is preferably prepared by adding the dye, binder resin, release agent and other optional components in a suitable solvent to dissolve or disperse each component to form a coating for forming a thermal sublimation ink layer. It is prepared, and this is applied and dried on the above-mentioned base material sheet to form. The thermal sublimation ink layer thus formed has a thickness of 0.2 to 5.0 μm.
m, preferably about 0.4 to 2.0 μm,
The dye in the thermal sublimation ink layer is preferably present in an amount of 5 to 90% by weight, preferably 10 to 70% by weight, based on the weight of the thermal sublimation ink layer.

The receiving layer, which is appropriately provided on the surface to be transferred in order to receive the dye or the like which is transferred at the time of transfer and to maintain the formed image, may be, for example, a polyolefin resin such as polypropylene, polyvinyl chloride, or polyvinyl chloride. Halogenated polymers such as vinylidene, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl polymers such as polyacrylic ester, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, ethylene and propylene. Examples thereof include copolymer resins of olefins and other vinyl monomers, ionomers, cellulose resins such as cellulose diacetate, polycarbonates, and the like, and vinyl resins and polyester resins are particularly preferable. The receptive layer is obtained by adding a necessary additive such as a release agent to the resin as described above, dissolved in a suitable organic solvent or a dispersion dispersed in an organic solvent or water, for example, a gravure printing method, It is formed by applying and drying by a forming means such as a screen printing method or a reverse roll coating method using a gravure plate. The receptive layer and / or the heat sublimable ink layer preferably contains a release agent for the purpose of preventing heat fusion of these layers. As a release agent,
Examples thereof include silicone oils, phosphate ester-based surfactants, and fluorine-based surfactants, with silicone oils being preferred. As the silicone oil, modified silicone oils such as epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkylpolyether-modified, epoxy-polyether-modified and polyether-modified are preferable.

The heat resistant slipping layer, which is optionally provided on the surface of the base material sheet in contact with the thermal head, comprises a heat resistant resin and a substance acting as a thermal release agent or a lubricant. And As a heat-resistant resin, a compound having two or more amino groups or a diisocyanate or triisocyanate is added to a synthetic resin having a glass transition point of 60 ° C. or more or a thermoplastic resin having an OH group or a COOH group, and a slight crosslinking curing is performed. It is preferable to cause the above.
Thermal release agents or lubricants, such as waxes and amides, esters and salts of higher fatty acids, which act by being melted by heating, and those which serve as a solid such as fluororesin and inorganic substance powders There is.

When a laser is used as the heating means, the light absorbing layer provided on the surface of the substrate sheet 1 or an intermediate layer thereof has a light absorbing heating element and a heat resistant binder as basic constituent components. As the heat resistant binder, for example, polyether sulfone, polyether imide, polyphenylene oxide, heat-insoluble polyimide resin, phenol, epoxy,
Thermosetting resins such as polyurethane, aromatic polyamide resins and the like can be mentioned. As the light absorption heating element dispersed in these resins, any material can be used as long as it is a material capable of absorbing light and converting heat, but a material having absorption at the oscillation wavelength of laser light is particularly desirable. , For example,
Carbon black, graphite powder, phthalocyanine dyes with metal coordination such as copper phthalocyanine, vanadyl phthalocyanine, etc., or atomized graphite, copper sulfide, lead sulfide, black titanium, polymethine dyes, azurenium dyes, squarylium dyes Infrared absorbers and the like are listed. Further, the above light absorbing heat generating element may be directly mixed in the base material sheet or the heat sensitive recording material layer.

As the opaque sheet 3 used in the embodiment shown in FIG. 1 of the present invention, the material used for the base sheet of the heat-sensitive coloring material or the base sheet of the heat-sensitive transfer material can be used as it is. The material is not particularly limited as long as it is opaque or opaque-treated, and any material can be used.

[0021]

According to the present invention, the thermal head or the thermal recording material portion is covered with the opaque-treated base sheet and the opaque sheet, or the opaque-treated base sheet and its folded portion. Since the data is recorded using a laser, etc., its contents cannot be viewed directly from outside. Also, by providing a thermosensitive coloring layer or the like in the area other than the covering portion, the output of confidential contents is selected in the covering area, and the output of other visible information is selected in the area other than the covering portion. Output can be performed.

[0022]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the text, “part” or “%” is based on weight unless otherwise specified.

EXAMPLE 1 A 12 μm thick condenser paper was prepared as a base sheet, and the following ink composition for forming a thermosensitive coloring material layer had a dry thickness of 1.0 g / m 2 in the left half area on one side thereof. After being coated and dried by gravure printing so as to be ² , the right half of the base material sheet is folded back so as to cover the surface of the thermosensitive coloring material layer as shown in FIG.
As in 2, the three sides were attached via an adhesive to obtain the heat-sensitive recording material of the present invention. Ink for forming a thermosensitive coloring material layer : Bisphenol A 34 parts Fluoran leuco dye (TH106 manufactured by Hodogaya Chemical Co., Ltd.) 85 parts Vinyltoluene / butadiene copolymer 120 parts (Pryolite VT manufactured by Goodyear) Ethylcyclohexane 500 parts

Example 2 A 4.5 μm-thick polyethylene terephthalate film having a heat resistant slipping layer provided on the back side was prepared as a base sheet, and a carbon black mixed primer layer was provided on the entire surface of one side of the film. The following thermal transfer material layer-forming ink composition was applied and dried by gravure printing so that the thickness when dried was 5.0 g / m ² , and as shown in FIG. The high-quality papers are stacked so as to cover the layer surface, and the peripheral portion and the base material sheet are as shown in FIG.
The four sides were attached via an adhesive to obtain a heat-sensitive recording material of the present invention. Ink for forming thermal transfer material layer : Carnauba wax emulsion (solid content 40%) 50 parts Ethylene / vinyl acetate copolymer emulsion (solid content 40%) 30 parts Carbon black aqueous dispersion (solid content 40%) 20 parts

Example 3 As a base sheet, a 6.0 μm-thick polyethylene terephthalate film having a heat resistant slipping layer provided on the back side and carbon black mixed therein was prepared. A thermal transfer material layer-forming ink composition similar to that of No. ² was applied by gravure printing so as to have a dry thickness of 4.0 g / m ² and dried, and then, as shown in FIG. In order to cover the above, a high-quality paper having a size larger than that of the base material sheet was superposed, and the high-quality paper and the peripheral portion of the base material sheet were adhered on four sides with an adhesive as shown in FIG. Further, as shown in FIG. 13, the same ink composition for forming a thermosensitive coloring material layer as in Example 1 was applied to the area other than the coated portion of the woodfree paper to obtain the thermosensitive recording material of the present invention.

Example 4 A 12 μm thick condenser paper was prepared as a base sheet, and the same ink composition for forming a thermosensitive coloring material layer as that of Example 1 was applied to the central region and the left end region of one surface thereof when dried. After applying and drying by gravure printing so as to be 1.0 g / m ² , as shown in FIG. 8, the right half of the base sheet is folded back so as to cover the surface of the thermosensitive coloring material layer in the left side region,
As shown in FIG. 14, the peripheral portion and the base material sheet were adhered to the three sides via an adhesive to obtain a heat-sensitive recording material of the present invention.

When the above thermal recording material was set in a printer and printing was performed from the side of the base material sheet with the thermal head 5, it was not possible to read the printed contents of the coated portion.

[0028]

[Effects] According to the present invention as described above, a heat-sensitive recording material in which a heat-sensitive recording material layer is provided on an opaque-treated base sheet,
By covering the surface of the thermosensitive recording material layer with the extension of the opaque sheet or the base sheet, it was possible to keep the confidentiality of the print content from a third party until the extension of the opaque sheet or the base sheet was peeled off after printing. ..

[Brief description of drawings]

[Figure 1]

FIG. 4 is a diagram schematically illustrating a cross section of a heat-sensitive recording material of the present invention.

FIG. 5 is a diagram schematically illustrating a printing state using the thermosensitive coloring material of the present invention.

FIG. 6 is a diagram schematically illustrating a printing state using the heat-sensitive transfer material of the present invention.

[Figure 7] ~

FIG. 10 is a diagram schematically illustrating a cross section of the heat-sensitive recording material of the present invention.

FIG. 11:

FIG. 14 is a plan view illustrating a state in which the base sheet and the opaque sheet of the present invention or the base sheet and the folded back portion of the base sheet are attached.

[Explanation of symbols]

 1: Base material sheet 2: Thermal recording material layer 3: Opaque sheet 4: Extension part of base material sheet 5: Thermal head 6: Adhering portion 7: Thermal recording material layer 8: Heat resistant slipping layer 9: Light absorbing layer 10 : Colorant receiving layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideaki Amano 1-1-1, Ichigayaka-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd.

Claims (6)

[Claims] 1. A heat-sensitive recording material having a heat-sensitive recording material layer provided on an opaque-treated base sheet, and an opaque sheet are attached at their peripheral portions so as to cover the surface of the heat-sensitive recording material layer. A heat-sensitive recording material characterized in that 2. A heat-sensitive recording material comprising a heat-sensitive recording material layer provided on an opaque-treated base sheet, wherein the extension of the base sheet is folded back so as to cover the heat-sensitive recording material layer surface. A heat-sensitive recording material, characterized in that a base material sheet extended portion which is folded back with the recording material is attached to the peripheral portion thereof. 3. The heat-sensitive recording material according to claim 1, wherein the heat-sensitive recording material layer is also provided in a region other than the area covered with the opaque sheet. 4. The heat-sensitive recording material according to claim 2, wherein the heat-sensitive recording material layer is also provided in a region other than the area covered by the extension of the folded back base sheet. 5. The thermosensitive recording material according to claim 1, wherein the thermosensitive recording material layer is formed of a thermosensitive coloring material. 6. The heat-sensitive recording material according to claim 1, wherein the heat-sensitive recording material layer is formed of a heat-sensitive transfer material.