JPH0551671U - Thermal recording medium - Google Patents

Abstract

(57) [Summary] [Object] To provide a thermal recording medium which is excellent in matching property of a thermal head and which is a colored medium and which enables clear thermal recording. [Structure] A support and a colored layer, a metal thin film layer on one side thereof,
An under layer between the support and the colored layer, an adhesive layer (I) between the colored layer and the metal thin film layer, and an adhesive layer (II) between the metal thin film layer and the protective layer are optional as a protective layer. A thermosensitive recording medium as a constituent, wherein at least one of the adhesive layer (II) and the protective layer contains a colorant.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a thermosensitive recording medium used for output recording of electronic computers, facsimiles, tickets, labels, cards, etc. and recorded by utilizing physical changes due to heating.

[0002]

[Prior Art]

 The thermal recording method, in which an image is obtained by utilizing the physical or chemical change of a substance caused by thermal energy, does not generate noise during recording, does not require developing and fixing, etc. Of course, it is expected to continue as output records of electronic computers, reception records of facsimiles, print records on tickets, labels and cards. Many types of recording materials have been proposed up to the present as a recording material for this thermal recording method. Among them, recording materials containing a leuco dye such as a fluoran dye as a color former have excellent thermal sensitivity. It is used in various fields. However, the thermosensitive recording paper using the lycophor as a color former has many drawbacks such that it is easily colored by pressure or an organic solvent such as alcohol, and is also poor in light resistance, heat resistance and water resistance. It is a thing. In order to solve such a drawback, a thermosensitive recording medium using a metal thin film layer as a thermosensitive layer has been developed. In this method, the metal thin film layer is imagewise destroyed by a heat source such as a thermal head, laser light, or flash light, and the colored layer provided below the metal thin film layer is lifted to form an image. is there. However, since chromatic colorants other than black have recently begun to be used in the lower layer of the metal thin film layer, a recorded image with higher contrast is required in relation to the color of the colorant, and at the same time, cards and tickets are required. Even more colorful colored surfaces are needed. However, since the surface of the conventional thermal recording medium having the metal thin film layer as the heat sensitive layer is mainly composed of the background color of the metal thin film layer, there is a problem that the above requirements cannot be satisfied. It was

[0003]

[Problems to be solved by the device]

 The object of the present invention is to provide a heat-sensitive recording medium having a metal thin film layer which solves the above-mentioned drawbacks and which has excellent image contrast, that is, recognizability of character images, and has heat resistance, light resistance, chemical resistance, abrasion resistance, and thermal resistance. It is to provide the one with excellent matching property with the head.

[0004]

[Means for Solving the Problems]

 That is, a support, a colored layer sequentially provided on one side of the support in the outward direction, a metal thin film layer, and a protective layer are essential components, and an under layer between the support and the colored layer, a colored layer and a metal are provided. The adhesive layer (I) between the thin film layers and the adhesive layer (II) between the metal thin film layer and the protective layer are optional components, and at least one of the adhesive layer (II) and the protective layer contains a colorant. It is a heat-sensitive recording medium.

The present invention will be described below with reference to the drawings. The thermal recording medium of the present invention comprises a combination of a support 1, a colored layer 2, a metal thin film layer 3, a protective layer 4, an underlayer 5, an adhesive layer (I) 6 and an adhesive layer (II) 7. 1 to 5 show examples of the layer structure. That is, FIG. 1 shows a basic structure consisting only of the essential constituent elements of the thermal recording medium of the present invention, in which a colored layer 2, a metal thin film layer 3 and a protective layer 4 are sequentially laminated on one side of a support 1. is there. Further, FIG. 2 shows a structure in which an adhesive layer (I) 6 which is an optional constituent element is provided between the colored layer 2 and the metal thin film layer 3 in addition to the basic constituent elements of FIG. In addition to the basic structure of FIG. 1, FIG. 3 has a structure in which an adhesive layer (II) 7, which is an optional component, is provided between the metal thin film layer 3 and the protective layer 4. Further, FIG. 4 has a configuration in which an adhesive layer (I) and an adhesive layer (II) which are optional components are provided in addition to the basic configuration of FIG. Further, FIG. 5 shows a structure in which, in addition to the structure of FIG. 4, an under layer 5 which is an optional component is provided between the support 1 and the coloring layer 2. The present invention contains a colorant in at least either the adhesive layer (II) 7 or the protective layer 4 in such a structure.

Each of the above layers will be specifically described. Examples of the support 1 include polyethylene terephthalate film and other plastics which are mechanically tough and flexible, coated paper, art paper, laminated paper, glass, metal and the like. The colored layer 2 is a layer that appears as an image by imagewise heating, and includes a cellulose derivative such as ethyl cellulose, hydroxyethyl cellulose, cellulose acetate propionate, or cellulose acetate, or a styrene resin such as polystyrene or poly-α-methylstyrene. Styrene copolymer resin, polymethylmethacrylate, ethyl polymethacrylate, ethyl polyacrylate, polybutyl acrylate, etc.Acrylic resin or methacrylic resin homo- or copolymer resin, rosin, rosin-modified phenolic resin, rosin-modified malein Acid resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin, coumarone resin, vinyltoluene resin, vinyl chloride resin, polyester resin, polyurethane resin, butyral resin, etc. Use a colored paint or ink prepared by adding various pigments or dyes and, if necessary, plasticizers, stabilizers, waxes, curing agents, dispersants, and then thoroughly kneading them with a solvent or diluent. Then, it can be formed at a desired portion by a coating method or a printing method such as a usual gravure method, a roll method, a knife edge method, an offset method and the like.

The metal thin film layer 3 is formed of a metal such as Te, Sn, Al, Bi, Pb, Zn or an alloy thereof or a compound of the above metal such as Te / carbite by vacuum deposition, sputtering or plating. For example, it can be formed on the colored layer 2 provided on the support 1. Since this layer plays a role as a heat-sensitive recording layer, it preferably has a low melting point. The thickness of this layer is 100 Å to 1 μm, preferably about 300 to 600 Å. In addition to physically and chemically protecting the metal thin film layer, the protective layer 4 is required to be free from staking and dust adhesion when recording with a thermal head. Therefore, it is necessary that the constituent material of the protective layer 4 contains a colorant described later, and in addition to this, it is desirable to contain at least three components of an acrylic resin, a lubricant and a heat resistant pigment. The acrylic resin used for the protective layer 4 includes methacrylic acid, acrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, It is obtained by homopolymerizing or copolymerizing monomers such as styrene. In consideration of abrasion resistance, the acrylic resin preferably has a Tg of 30 ° C. or higher.

Examples of the lubricant include waxes such as polyethylene wax, paraffin wax, and microcrystalline wax, higher fatty acid metal salts such as zinc stearate and calcium stearate, higher fatty acid amides such as stearic acid amide and behenic acid amide, and silicone. Materials such as oil, fluororesin fine powder, and boron nitride fine powder are included. The heat resistant pigment is mainly selected from inorganic pigments such as silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, zeolite, clay and talc.

The preferable content ratios of the above acrylic resin, lubricant and heat resistant pigment in the protective layer are 60 to 95% by weight, 2 to 25% by weight and 2 to 40% by weight, respectively. Next, the under layer 5 is provided between the support 1 and the coloring layer 2 to improve the adhesiveness between the two, and does not require any special restriction and can be selected from many conventionally known polymers. Is. For example, as the solvent-soluble polymer, polyester, polyurethane, or acrylic resin is used, while as the water-soluble polymer, polyvinyl alcohol, starch, various emulsion resins, or the like is applied.

The adhesive layer (I) 6 is provided between the colored layer 2 and the metal thin film layer 3 to improve the adhesive force between them. Further, at the time of thermal recording, a polymer having an appropriate thermoplasticity is used in order to promote the destruction of the metal thin film layer 3 and also to improve the thermal recording sensitivity. Specific examples include acrylic resins such as polystyrene and polymethylmethacrylate, cellulosic resins such as cellulose acetate propionate, vinyl chloride-vinyl acetate copolymers, polyester resins, polyurethane resins and epoxy resins. In order to control the thermoplasticity, it is possible to add a heat-fusible substance such as a plasticizer or wax. Further, a hardening agent may be used in order to give the adhesive layer (I) a certain solvent resistance and facilitate the lamination of the next layer.

The adhesive layer (II) 7 is provided between the metal thin film layer 3 and the protective layer 4 so as to improve the adhesive force between the metal thin film layer 3 and the protective layer 4, and physically and chemically protects the metal thin film layer 3 together with the protective layer 4. Protective work is also required. Polyester resin, polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, cellulose resin and the like are suitable as the resin used in consideration of chemical resistance. Further, in the heat-sensitive recording medium of the present invention, at least one of the above-mentioned adhesive layer (II) and protective layer contains a colorant. As the colorant used here, any of organic and inorganic pigments and dyes can be used, but inorganic pigments are particularly preferable. To give a specific example, as dyes, for cyan dyes, it is Diaselington Fast Brilliant Blue R (trade name, manufactured by Mitsubishi Kasei), Kayaron Polyester Blue B-SF Conc (trade name, manufactured by Nippon Kayaku Co., Ltd.) ) Etc., magenta color dyes such as Diaceriton Fast Red R (manufactured by Mitsubishi Kasei Co., Ltd., trade name), Kayaron Polyester Pink RCL-E (manufactured by Nippon Kayaku Co., Ltd. trade name), etc., and yellow dyes such as Kayaron Polyester Light Yellow 5G-S (manufactured by Nippon Kayaku Co., Ltd., trade name), Eisenspirone Yellow GRH (manufactured by Hodogaya Chemical Co., Ltd., trade name) and the like can be mentioned. In addition, cyan pigments include cerulean blue and phthalocyanine blue, magenta pigments include brilliant carmine and alzaline lake, yellow pigments include Hansa yellow and bisazo yellow, and black pigments include carbon black, graphite, and oil. Examples thereof include black, and these can be used alone or in combination. Pigments are preferable to dyes in terms of light resistance. In carrying out the present invention, a magnetic recording layer may be provided on the back surface of the support, or an adhesive layer and a separator may be provided for labeling. It is also possible to print on the protective layer.

[0012]

【Example】

Examples will be described below. However, "parts" means "weight ratio". Example 1 A thermosensitive recording medium of the present invention was obtained by sequentially laminating the following layers on a milk-white polyethylene terephthalate film having a thickness of 188 μm by coating. (1) Colored layer: The following composition was applied at a drying temperature of 110 ° C. and a coating amount of 3.2 g / m ² .・ Linear saturated polyester resin solution 18 parts (Toyobo Co., Ltd .: Byron MT240, solid content 40%) ・ Colorant 2 parts (Hodogaya Chemical Co., Ltd .: Eisenspirone Violet RH Special) ・ Particulate silica 1 part (Tokuyama) Soda: Fineseal X70, average particle size 2.0 μm) Methyl ethyl ketone 10 parts Toluene 8 parts Isocyanate curing agent 0.4 parts (Nippon Polyurethane Co .: Coronate L) (2) Metal thin film layer: Vacuum deposition By vapor deposition, tin was vapor-deposited so as to have a thickness of 600 Å when measured by the film thickness measurement method by the crystal oscillator method. (3) Adhesive layer (II): The following composition was applied at a drying temperature of 110 ° C. and a coating amount of 1.3 g / m ² .・ Vinyl chloride vinyl acetate copolymer 7 parts (Sekisui Chemical Co., Ltd .: trade name S-REC C) ・ Acrylic resin 3 parts (acid value 54, OH value 36, Tg 84 ° C) ・ Methyl ethyl ketone 30 parts ・ Toluene 60 parts (4) Protection Layer: The following composition was coated at a drying temperature of 110 ° C. and a coating amount of 2.1 g / m ² . -Polymethylmethacrylate solution 1000 parts (Soken Chemical Co., Ltd .: Thermolac M-2000, solid content 10%)-Oxide microwax 5 parts (acid value 15, melting point 100 ° C) -Aluminum hydroxide 5 parts-Colorant 15 Part (Hodogaya Chemical Co., Ltd .: Aizenspirone BROWN BRHS liquid, solid content 30%) ・ Toluene 20 parts

Example 2 A thermosensitive recording medium of the present invention was obtained by sequentially laminating the following layers on a milky-white polyethylene terephthalate film having a thickness of 188 μm by coating or the like. (1) Colored layer: A colored layer was provided in the same manner as in Example 1 except that the colorant in Example 1 was replaced with 2 parts of Eizen Red BEH. (2) Adhesive layer (I): The following composition was applied at a drying temperature of 110 ° C. and a coating amount of 1.8 g / m ² .・ Aqueous polyolefin resin 20 parts (manufactured by Steel Manufacturing Chemical Co., Ltd: Zyksen AC, solid content 30%) ・ Fine powder silica 1 part (manufactured by Tokuyama Soda Co., Ltd .: Fineseal X-70, average particle size 2.0 μm) ・ Trimethylolpropane -Tri-β-aziridinyl propionate 0.2 parts-Isopropyl alcohol 3 parts-Water 5 parts (3) Metal thin film layer: when indium is measured by a vacuum vapor deposition method by a film thickness measurement method by a crystal oscillator method. It was vapor-deposited so as to be 500 Å. (4) Adhesive layer (II): The following composition was applied at a drying temperature of 110 ° C. and a coating amount of 1.3 g / m ² . -Vinyl chloride-vinyl acetate copolymer 7 parts (Denka Vinyl 1000 GKT manufactured by Denki Kagaku Kogyo Co., Ltd.)-Acrylic resin 3 parts (acid value 54, OH value 36, Tg 84 ° C) -Colorant 15 parts (Hodogaya Chemical Co., Ltd. : Eisenspirone BLUE2BNH liquid, solid content 35%) 1 part Methyl ethyl ketone 30 parts Toluene 60 parts (5) Protective layer: The following composition was applied at a drying temperature of 110 ° C. and an application amount of 2.1 g / m ² . .・ Acrylic resin 200 parts (manufactured by Mitsubishi Rayon Co., FR4238, solid content 45%) ・ Oxide microwax 5 parts (acid value: 15, melting point: 100 ° C.) ・ Aluminum hydroxide 5 parts ・ Toluene 800 parts

Comparative Example 1 A thermal recording medium for comparison was prepared in the same manner as in Example 1 except that the colorant in the protective layer was removed. Comparative Example 2 A thermal recording medium for comparison was prepared in the same manner as in Example 2 except that the coloring agent in the adhesive layer (II) was removed.

The following characteristic evaluation was performed on the thermal recording medium manufactured as described above. (1) Recording characteristics An image was recorded by a thermal head with a pulse width of 2.5 ms and an applied energy of 0.6 W. The recording density and background density were measured using a Macbeth densitometer RD-914 (visual filter). (2) Character Recognition The distinguishability of the colored characters with respect to the colored background color was judged by 10 persons. The evaluation results are shown in Table 1 in three grades of ◯, Δ, and ×. (3) Head matching property Printing was performed for 10,000 pulses continuously under the above recording conditions, and the sticking and scrap attachment conditions were examined. (4) Light resistance After exposure with a fade meter for 6 hours, the densities of the recorded part and the background were similarly measured with a Macbeth densitometer. (5) Water resistance Water resistance was examined by immersing in water at 20 ° C. for 3 days. (6) Alcohol resistance A 50% aqueous solution of ethanol was dropped, and after 2 minutes, wiping was performed to examine alcohol resistance. (7) Oil resistance Cotton seed oil was applied and left at 20 ° C for 24 hours to examine the oil resistance. (8) Plasticizer resistance A plastic eraser (Dragonfly Mono) was loaded with a load of 100 g, and left at 20 ° C for 24 hours to examine the plasticizer resistance. (9) Heat resistance The heat resistance was examined by placing it in a dryer at 100 ° C for 10 minutes. (10) Abrasion resistance The abrasion resistance was examined by passing the gate of the automatic ticket gate 2000 times in the same direction.

[0016]

[Table 1]

As is clear from Table 1, the thermosensitive recording medium of the present invention has good recording characteristics, particularly excellent in distinguishability of characters, and also has a head matching property and a light resistance which are indicators of sticking and dust adhesion. All of the practical properties required for the isothermal recording medium were similarly satisfied.

[0018]

[Effect of the device]

 Since the present invention is composed of the above-mentioned structure and materials, it has excellent heat resistance, light resistance, water resistance, chemical resistance, abrasion resistance, and the like, and also has excellent head matching and excellent character recognition. A thermal recording medium can be provided. In addition, by selecting an arbitrary chromatic color as the colorant, it is possible to use different colors for different applications such as cards and tickets, which has made it possible to develop a wider range of applications.

[Brief description of drawings]

FIG. 1 is a sectional view of a thermal recording medium obtained by the present invention.

FIG. 2 is a sectional view of a thermosensitive recording medium obtained by the present invention.

FIG. 3 is a sectional view of a thermosensitive recording medium obtained by the present invention.

FIG. 4 is a sectional view of a thermosensitive recording medium obtained by the present invention.

FIG. 5 is a sectional view of a thermal recording medium obtained by the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 2 Colored layer 3 Metal thin film layer 4 Protective layer 5 Under layer 6 Adhesive layer (I) 7 Adhesive layer (II)

Claims (1)

[Scope of utility model registration request] 1. A support, a colored layer sequentially provided on one side of the support in an outward direction, a metal thin film layer, and a protective layer as essential components, and an under layer between the support and the colored layer and a coloring layer. In the heat-sensitive recording medium, the adhesive layer (I) between the metal layer and the metal thin film layer and the adhesive layer (II) between the metal thin film layer and the protective layer are optional components. A heat-sensitive recording medium, characterized in that at least one layer contains a colorant.