JPH06179293A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To provide a thermal transfer sheet not generating wrinkless due to printing and preventing the contamination of a thermal head by imparting thermal releasability to a heat-resistant slip layer and rapidly separating the heat-resistant slip layer from a thermal head at the time of the completion of printing without welding the same to the head. CONSTITUTION:In a thermal transfer sheet wherein a thermal transfer colorant layer is formed on one surface of a base material film and a heat-resistant slip layer is formed on the other surface thereof, the heat-resistant slip layer contains a thermal release agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal transfer sheet,
More specifically, the present invention relates to a thermal transfer sheet which is composed of a heat resistant slipping layer containing a specific composition and which has improved wrinkles due to printing and contamination of the thermal head.

[0002]

2. Description of the Related Art A conventional thermal transfer sheet uses a plastic film such as a polyester film as a base film, and a sublimation type thermal transfer in which a dye layer composed of a sublimable dye and a binder is provided on one surface of the base film. There is a heat melting type thermal transfer sheet in which a sheet and an ink layer made of a heat melting composition instead of the dye layer are provided.
These thermal transfer sheets are imagewise heated from the back side by a thermal head to transfer the ink layer to the transfer material to form an image. Further, in a conventional thermal transfer sheet, when a material that melts at a temperature above the melting point of the base plastic, such as a plastic film, is used as the base material film, it is fused to the thermal head during printing and peels off and slips on the thermal head. In some cases, problems such as impaired properties and breakage of the base film may occur.
In order to solve such problems, it has been proposed to apply a heat resistant slipping layer containing a lubricant or an inorganic or organic fine powder to the surface of the base film opposite to the ink layer.

[0003]

However, such a heat-resistant slipping layer can secure the sliding property to the thermal head, and when forming an image of the entire surface of the heat transferable sheet or a size close to it, printing wrinkles are generated. Did not occur. However, when the printing portion and the non-printing portion are on the same line (for example, a checkerboard pattern), there is a problem that a slippage difference occurs between the two and a printing wrinkle occurs. Also,
At the end of printing, that is, at the moment when the thermal head has finished energizing, the heat resistant slipping layer does not immediately separate from the thermal head,
There is a problem that dust is accumulated or wrinkles are generated on the common electrode side of the thermal head.

[0004]

In order to achieve the above-mentioned object, the present invention has a heat transferable color material layer formed on one surface of a substrate film and a heat resistant slipping layer formed on the other surface. A heat transfer sheet comprising the above, wherein the heat resistant slipping layer contains a heat release agent.

[0005]

[Function] By including a heat release material in the heat resistant slipping layer,
It imparts thermal releasability to the heat resistant slipping layer so that the heat resistant slipping layer can be quickly separated from the thermal head at the end of printing without being fused to the thermal head.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. As the base material sheet constituting the thermal transfer sheet of the present invention, any one having conventionally known heat resistance and strength can be used.
Paper having a thickness of 5 to 50 μm, preferably 3 to 10 μm, processed paper polyester film thereof, 1,4-polycyclohexylene dimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone A film, an aramid film, a polycarbonate film, a polyvinyl alcohol film, cellophane, etc., and a particularly preferable one is a polyethylene terephthalate film (polyester film). It is also preferable to form an adhesive layer (primer layer) on one side or both sides of the film, if necessary. These base sheets may be single sheets or continuous sheets supplied by winding, and the material can be selected according to the application.

The heat resistant slipping layer of the present invention formed on one surface of the above-mentioned base sheet is a thermal release agent, and a lubricant, inorganic or organic fine powder optionally added, and a surfactant. The antistatic agent is included in a resin binder which is a film forming agent.

The thermal release agent required in the present invention is a phosphoric ester type surfactant, polyethylene wax, montan wax, dimethylpolysiloxane, methylphenylpolysiloxane, fatty acid amide, fatty acid ester, long chain aliphatic compound, One or more of low molecular weight polypropylene, block copolymer of ethylene oxide and propylene oxide, condensate of fatty acid salt and polyether compound, and perfluoroalkylethylene oxide adduct are used. The thermal release agent is added in an amount of 1 to 100 parts by weight, preferably 2 to 50 parts by weight, based on 100 parts by weight of the binder resin. When the addition amount of the thermal release agent is small, the thermal release property to the thermal head is not sufficiently obtained, which causes printing wrinkles and head residue, and when the addition amount is too large, the thermal transfer sheet may not be wound up. Upon storage, the dye of the corresponding heat transferable colorant layer migrates to the heat resistant slipping layer, and sufficient thermal releasability cannot be obtained, causing print wrinkles and head residue.

The fine powder used in the present invention can be used regardless of whether it is inorganic or organic. However, in order to avoid the abrasion of the surface of the thermal head as much as possible, the inorganic filler is
Calcium carbonate, precipitated barium sulfate, magnesium carbonate and the like are available, but those having caustic properties such as kaolin and clay and having low hardness are preferable. As the organic filler, those having lubricity such as silicone powder and Teflon filler are preferable. In addition to these, conductivity such as carbon black and copper phthalocyanine pigment,
It is also possible to use finely colored powders. The average particle size of these fine powders is 0.01 to 10 μm, preferably 0.1 to 10 μm.
It is 5 μm. By containing the fine powder, the surface can be roughened, and the friction coefficient can be reduced by making the contact point with the thermal head small, and in addition, the slipperiness of the fine powder itself can be imparted. Furthermore, by roughening the surface, it is possible to impart workability such as wrinkles during winding.
As the lubricant to be used, various kinds of surfactants and silicone oils can be used. However, when the heat resistant slipping layer has a crosslinked structure, a certain amount of heat resistance can be obtained by having a reactive group adapted to the crosslinked body. It is fixed on the surface of the slipping layer or in the layer, and it is possible to prevent the change of the slipping property due to the environment or the change with time and the transfer to the surface of the heat transferable color material layer.

The resin constituting the heat resistant slipping layer may be a thermosetting resin, an ionizing radiation curable resin or the like as long as it has a film forming ability, but a preferable one is a thermoplastic resin or a crosslinked product thereof. For example, as the thermoplastic resin, polyester resin, polyacrylic ester resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin, polyether Resin, polyamide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylate resin, polyacrylamide resin, polyvinyl chloride / vinyl acetate copolymer derivative, polyvinyl butyral resin, polyvinyl acetoacetal resin, etc. A thermoplastic resin is used, and polyvinyl butyral resin and polyvinyl acetoacetal resin are particularly preferable.

Furthermore, it is more preferable to use a binder containing a polyisocyanate as a cross-linking agent, which imparts heat resistance, coating strength and adhesion to the base film for the slipping layer. These polyisocyanates may be the polyisocyanates conventionally used in the synthesis of paints, adhesives or polyurethanes known in the art. These polyisocyanate compounds are, for example, Takenate (manufactured by Takeda Yakuhin),
It can be used in the present invention by obtaining it under the trade names such as Bernock (manufactured by Dainippon Ink and Chemicals), Coronate (manufactured by Nippon Polyurethane), Duranate (manufactured by Asahi Kasei), and Dismodule (manufactured by Bayer). The amount of polyisocyanate added is appropriately in the range of 5 to 200 parts by weight with respect to 100 parts by weight of the resin of the binder constituting the slipping layer. -NC
The O / -OH ratio is preferably in the range of 0.6 to 2.0. When the amount of polyisocyanate used is insufficient, the heat resistance is insufficient due to the low cross-linking density. On the other hand, when the amount of polyisocyanate is too large, the shrinkage of the coating film formed cannot be controlled, the curing time is prolonged, and unreacted The NCO group may remain in the slipping layer and may have a negative effect such as reacting with moisture in the atmosphere.

To form the heat resistant slipping layer, a coating solution is prepared by dissolving or dispersing the above materials in a solvent such as acetone, methyl ethyl ketone, toluene or xylene selected to suit the coating suitability. It is formed by applying, drying and solidifying this coating solution by a conventional coating means such as a gravure coater, a roll coater and a wire bar. The coating amount, that is, the thickness of the heat resistant slipping layer is 3.
It is preferably 0 g / m ² or less, preferably 0.1 to 1.0 g /
A heat resistant slipping layer having sufficient performance can be formed with a thickness of m ² . Incidentally, since the heat-resistant slipping layer is applied and dried in the layer, unreacted isocyanate groups often remain,
It is preferable to perform heating and aging treatment to complete the reaction. It is also effective to provide a primer layer prior to forming the heat resistant layer.

As the heat transferable color material layer formed on the other surface of the substrate sheet, a layer containing a sublimable dye is formed in the case of a sublimation type heat transfer sheet, and a heat melting type heat transfer sheet is formed. A layer is formed with a hot-melt ink colored with a pigment or the like. The sublimation type thermal transfer sheet will be described in detail below as a representative example, but the present invention is not limited to the sublimation type thermal transfer sheet. As the dye of the heat transferable color material layer, any of the dyes used in conventionally known heat transfer sheets can be used in the invention and is not particularly limited. For example, some preferred dyes include MS Re as a red dye.
d G, Macrolex Red Violet
R, CeresRed7B, Samaron Red
HBSL, Resolin Red F3BS and the like, and yellow dyes such as Holon Brilliant Yellow 6GL, PTY-52 and Macrolex Yellow 6G, and blue dyes such as Kayacset Blue 714 and Waxolin. Examples include Blue AP-FW, Holon Brilliant Blue SR, MS Blue 100 and the like.

Examples of the binder resin for supporting the above dyes include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate and cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl. Vinyl resins such as acetal and polyvinylpyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, polyester resins, etc. Resins such as resins, vinyl resins, acrylic resins, polyurethane resins and polyester resins are preferably used in terms of heat resistance, dye transferability and the like.

The dye layer is provided on one surface of the base sheet,
Additives as necessary to the dyes and binders as described above,
For example, a means in which a release agent or the like is dissolved in an appropriate organic solvent or dispersed in an organic solvent or water, for example, a gravure printing method, a screen printing method, a reverse roll coating method, or the like is formed. Can be formed by coating and drying. The dye layer thus formed has a thickness of 0.2 to 5.0 μm, preferably 0.4 to 2.0 μm.
The sublimation dye in the dye layer has a thickness of about μm, and the sublimation dye is contained in an amount of 5 to 90% by weight, preferably 10 to 70% by weight of the dye layer.
It is preferably present in an amount of% by weight. When the image of the desired heat transferable color material layer is mono-color, one of the dyes is selected and formed, and when it is a full-color image, suitable cyan, magenta, and yellow (if necessary) Add black accordingly and select) to form.

The image-receiving sheet used for forming an image using the thermal transfer sheet as described above may be any image-receiving sheet as long as its recording surface has dye receptivity to the above-mentioned dye, and Paper, metal, which does not have dye receptivity
In the case of glass or synthetic resin, a dye receiving layer may be formed on at least one surface thereof. In the case of a heat-melting type heat transfer sheet, the material to be transferred is not particularly limited and may be ordinary paper or plastic film.
A known thermal transfer printer can be used as it is as a printer used when performing thermal transfer using the thermal transfer sheet and the image receiving sheet as described above, and is not particularly limited.

[0017]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. (Example 1) As a substrate sheet, a 4.5 μm polyester film was coated with the composition liquid for heat resistant slip layer A of the following A so as to have a thickness of 1.0 μm when dried, dried and further heat-aged. Then, curing treatment was performed to form a heat resistant slipping layer. On the back side, a thermal transfer color material ink layer of B below is 1.0 μm
Gravure printing was performed at a thickness of 1 to form a heat transferable color material layer to obtain a heat transfer sheet of the present invention. Heat-resistant ink layer A • Polyvinyl butyral resin (S-REC BX-1 made by Sekisui Chemical Co., Ltd.) 3.60 parts • Polyisocyanate (Bernock D750 made by Dainippon Ink) 8.40 parts • Modified silicone oil (Painted M Dow Corning) 2.40 Part-Fluon tetrafluoride resin fine powder (Fluon L170J manufactured by Asahi Glass Co., Ltd.) 0.60 part-Phosphate ester-based surfactant (phosphanol RD720 manufactured by Toho Kagaku) 0.40 part-Toluene 85.00 parts-Methyl ethyl ketone 85.00 Part heat transferable color material layer ink B / C. I Solvent Blue 22 5.50 parts-acetoacetal resin 3.00 parts-methyl ethyl ketone 22.54 parts-toluene 68.18 parts

Example 2 A thermal transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink C for heat resistant slipping layer described below was used in place of the heat resistant slipping layer used in Example 1. . Heat-resistant ink layer C ・ Polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.) 3.60 parts ・ Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.40 parts ・ Sorbitan acid fatty acid ester-based surfactant (Reodol SP-O)ー 30 Kao) 2.40 parts ・ Kaolinite (ASP-072 Tsuchiya Kaolin) 0.60 parts ・ Polyethylene wax (AF31 BASF product) 0.40 parts ・ Methyl ethyl ketone 85.00 parts ・ Toluene 85.00 parts

(Example 3) A heat transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink D for the heat resistant slipping layer described below was used in place of the heat resistant slipping layer in Example 1. . Heat-resistant ink layer D ・ Polyvinyl butyral resin (S-REC BX-1 Sekisui Chemical Co., Ltd.) 3.60 parts ・ Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.40 parts ・ Anionic surfactant (Chemistat 3033 manufactured by Sanyo Kasei) 2 .40 parts ・ Silicone resin fine powder (KMP590 manufactured by Shin-Etsu Chemical) 0.60 parts ・ Stearic acid amide (Amide AP-1 manufactured by Nippon Kasei) 0.40 parts ・ Methyl ethyl ketone 85.00 parts ・ Toluene 85.00 parts

Comparative Example 1 A thermal transfer sheet of the present invention was obtained in the same manner as in Example 1, except that the heat resistant slipping layer ink E described below was used instead of the heat resistant slipping layer in Example 1. . Heat-resistant ink layer E • Polyvinyl butyral resin (S-REC BX-1 manufactured by Sekisui Chemical Co., Ltd.) 3.60 parts • Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.40 parts • Modified silicone oil (manufactured by Paintad M Dow Corning) 2.40 Part-Four powdered tetrafluoroethylene resin powder (Fluon L170J manufactured by Asahi Glass Co., Ltd.) 0.60 part-Toluene 85.00 parts-Methyl ethyl ketone 85.00 parts

Comparative Example 2 A heat transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink F for heat resistant slipping layer described below was used in place of the heat resistant slipping layer in Example 1. . Heat-resistant ink layer F ・ Polyvinyl butyral resin (S-REC BX-1 manufactured by Sekisui Chemical Co., Ltd.) 3.60 parts ・ Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.40 parts ・ Sorbitan acid fatty acid ester-based surfactant (Reodol SP-Oー 30 made by Kao) 2.40 parts ・ Kaolinite (ASP-072 made by Tsuchiya Kaolin) 0.60 parts ・ Methyl ethyl ketone 85.00 parts ・ Toluene 85.00 parts

Comparative Example 3 A thermal transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink G for heat resistant slipping layer described below was used instead of the heat resistant slipping layer in Example 1. . Heat-resistant ink layer G-Polyvinyl butyral resin (S-REC BX-1 manufactured by Sekisui Chemical Co., Ltd.) 3.60 parts-Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.40 parts-Anionic surfactant (Chemist 3033 manufactured by Sanyo Kasei) 2 40 parts ・ Silicone resin fine powder (KMP590 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.60 parts ・ Methyl ethyl ketone 85.00 parts ・ Toluene 85.00 parts

(Evaluation Method) The above-mentioned thermal transfer sheet was overlaid on a conventional image-receiving sheet, and a commercially available video printer was used for solid printing in the maximum printable area (pattern A) and solid printing in the central part (pattern B). 2) patterns are printed, and the occurrence of wrinkles and the occurrence of head residue are visually determined. Judgment criteria: ○ Good △ Somewhat good × Bad

[0024]

INDUSTRIAL APPLICABILITY According to the present invention, the heat-resistant slip layer is provided with a heat-releasing material to impart heat-releasing property to the heat-resistant slip layer, and the heat-resistant slip layer is fused to the thermal head at the end of printing. Allows you to quickly leave the thermal head without having to.

[Table 1]

Claims (2)

[Claims] 1. A thermal transfer sheet having a heat transferable color material layer formed on one surface of a substrate film and a heat resistant slipping layer formed on the other surface, wherein the heat resistant slipping layer is a thermal release layer. A thermal transfer sheet containing an agent. 2. A phosphoric ester type surfactant, polyethylene wax, montan wax, dimethylpolysiloxane, methylphenylpolysiloxane, fatty acid amide, fatty acid ester, long chain aliphatic compound, low molecular weight polypropylene, as a thermal release agent. Characterized by using one or more of block copolymers of ethylene oxide and propylene oxide, condensates of fatty acid salts and polyether compounds, perfluoroalkyl betaines, perfluoroalkyl ethylene oxide adducts The thermal transfer sheet according to claim 1.