JPS63182190A - Dye for thermal transfer recording and thermal transfer sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transfer sheet used for sublimation anti-thermal transfer recording.

(Conventional technology) Conventionally, there has been a demand for technology for color recording facsimile printers, copying machines, television images, etc., and electrophotography,
Color recording technologies using inkjet, thermal transfer, etc. are being considered.

The thermal transfer recording method is considered to be advantageous over other methods because the device is easy to maintain and operate, and the device and consumables are inexpensive.

Thermal transfer methods include the melting method, in which a transfer sheet with a heat-melting ink layer formed on a base film is heated by a thermal head to melt the cough ink, and then transferred and recorded onto the recording medium; There is a sublimation method in which a transfer sheet on which an ink layer containing a sublimable dye is formed is heated by a thermal head to sublimate the dye and transfer and record onto the recording medium. Since the amount of sublimation transfer of the dye can be controlled by changing the applied energy, gradation recording becomes easy and is considered to be particularly advantageous for full color recording.

In thermal transfer recording using the sublimation method, the sublimable dye used in the transfer sheet is extremely important as it has a significant effect on the speed of transfer recording, the image quality of the recorded material, and the storage stability. It is necessary to meet the requirements.

■ Easily sublimated under the operating conditions of the thermal recording head.

■Do not thermally decompose under the operating conditions of the thermal recording head.

■ It must have a favorable hue in terms of color reproduction.

■ The molecular extinction coefficient is extremely high.

■ Stable against heat, light, humidity, building materials, etc.

■ Easy to synthesize.

■ Excellent suitability for ink production.

■ There are no health and safety problems.

A dye that satisfies all of the above conditions has not yet been found, and yellow dyes in particular have various drawbacks and have not yet been found to be satisfactory.

(Problems to be Solved by the Invention) The present invention is a thermal transfer sheet characterized by using a yellow dye that satisfies all of the above conditions. an optionally substituted alkoxyalkyl group, an optionally substituted aralkyloxyalkyl group, a tetrahydrofurfuryl group, a furfuryl group, an optionally substituted allyloxyalkyl group, or an optionally substituted aryloxyalkyl group The gist thereof is a heat-sensitive transfer sheet characterized by having a coloring material layer containing a pyrazolone azo dye represented by the following on a base film.

The pyrazolone azo dye represented by the general formula CI) used in the present invention will be explained.

In the above general formula [l], the optionally substituted alkoxyalkyl group represented by R includes neemethoxyethyl group, niethoxyethyl group, -1(n)propoxyethyl group 1.2-(iso)propoxy ethyl group,
! -(n) butoxyethyl group, 2-(iso)butoxyethyl group, -1(sea)butoxyethylxyethyl M, J-(n) hexyloxyethyl group, ni(n) octyloxyethyl group, ni( 2-ethylhexyloxy)ethyl group, /-methyl-2-methoxyethyl group, /-methyl-niethoxyethyl group, /-methyl-nie(n)globoxyethyl group, /-methyl-2-
(iso) propoxyethyl group, /-methyl-, 2-
(n) Butoxyethyl group, /-methyl-, 2-
(iso)butoxyethyl group, /-methyl-2-(n
) hexyloxyethyl group, /-methyl-(nee ethylhexyloxy)ethyl group, 3-methoxybfkM
, 3-ethoxybutyl group, /-ethyl-J-,)' t*diethyl group, /-ethyl-coethoxyethyl group, and the optionally substituted aralkyloxyalkyl group includes 2-benzyloxyethyl group. group, /-methyl-nibenzyloxyethyl group, /-ethyl-nipenzyloxyethyl group, S-(β-phenylethylnooxyethyl group, etc.), and optionally substituted allyloxyalkyl groups include is a ni-allyloxyethyl group, /-methyl-,2-allyloxyethyl group, l
-dityrunoallyloxyethyl group, etc.,
Examples of the optionally substituted aryloxyalkyl group include -monophenoxyethyl group, /-methyl-niphenoxyethyl group, l-ethyl-niphenoxyethyl group, and the like.

As a method for producing the above dye, for example, an azo dye obtained by diazotizing 0-trifluoromethylaniline by a conventional method and then ringing it with /-phenyl-3-ethoxycarbonyl-y-hydroxyvirazole. It is carried out by carrying out a transesterification reaction in an alcohol represented by the following general formula CIIIR-OH[[] (wherein R is the same as defined above) using a basic catalyst such as sodium methoxide. Can be done.

When applying the above dye to the thermal transfer sheet of the present invention,
An ink is prepared by dissolving or dispersing the dye in a medium together with a binder in the form of fine particles, and the ink is applied onto a base film and dried to form a coloring material layer on the base film.

As a binder for I/RI v4 pear, acrylic resin,
Resins soluble in organic solvents such as methacrylic resin, polystyrene, polycarbonate, polysulfone, polyester, polyether sulfone, polyvinyl butyral, ethyl cellulose, and acetyl cellulose can be used.

As a medium for ink preparation, methyl alcohol,
Isopropyl alcohol, inbutyl 7/l/coalnato alcohol m, cellosolves such as mef cellosolve and ethyl cellosolve, toluene, xylene, aromatics such as chlorobenzenato, esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, methyl Examples include ketones such as isobutyl ketone and cyclohexanone, chlorinated solvents such as methine chloride, chlorine, and trichloroethylene, ethers such as tetrahydrofuran and dioxane, and organic solvents such as N-dimethylformamide and N-methylpyrrolidone. be able to.

In addition to the above ingredients, the above ink also contains organic and inorganic non-sublimable fine particles, dispersants, antistatic agents, antiblocking agents, antifoaming agents, antioxidants, viscosity modifiers, etc.
Can be added.

Suitable base films for applying ink for making transfer sheets include thin paper such as condenser paper and glassine paper, and plastic films with good heat resistance such as polyester, polycarbonate, polyamide, polyimide, and polyaramid. , their thickness can range from 3 to 50 μm.

Among the above base films, polyethylene terephthalate film is particularly advantageous in terms of mechanical strength, anti-leaching properties, economic efficiency, etc. However, this film does not necessarily have sufficient heat resistance and has poor runnability of the thermal head. By providing a layer of heat-resistant resin containing a surfactant, highly slippery heat-resistant particles, etc. on the opposite side of the coloring material layer,
The running performance of the thermal head can be improved.

The ink can be applied to the base film using a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, etc. The thickness of the ink coating layer after drying is o, i ~ Just apply it so that it is within the range of 3 μm (Yuji Harasaki, Maki Shoten/
``Coating method'' published in 1979).

(Examples) The present invention will be specifically described below with reference to Examples, but these Examples do not limit the present invention.

Examples/a) Preparation of ink Vilazo;n-azo yarn dye of the above invention /θy cellulose acetate 109 (manufactured by Daicel Chemical Co., Ltd., L-, )0) Total 100 g
The mixture having the above composition was treated with a paint conditioner for 70 minutes to prepare an ink.

b) Preparation of transfer sheet The above ink was applied to a polyethylene terephthalate film (6 μm
A transfer sheet was obtained by coating the transfer sheet on a dry film with a dry film thickness of 1 μm.

The heat-resistant lubricity treatment of the polyethylene terephthalate film was performed by adding 5 parts by weight of polycarbonate having a repeating structural unit represented by the following formula, 5 parts by weight of a phosphoric acid ester surface active agent, and 5 parts by weight of a polycarbonate having a repeating structural unit represented by the following formula.
The test was carried out by applying a solution consisting of 9 parts by weight of NIBLY SURF A- (trade name: NIBLYSURF A-, 20 gB, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 9 parts by weight of toluene, and drying (O, S μm in dry film thickness).

C) Preparation of image receptor Saturated polyester resin (product name: TP-2,20, manufactured by Nippon Gosei Co., Ltd.) 10 parts, amine-modified silicone (product name: KF, 79.7, manufactured by Shin-Etsu Chemical Co., Ltd.)
A liquid consisting of 0.015 parts, 773 parts of methyl ethyl keto, and 75 parts of xylene was mixed with synthetic paper (product name: YUPO FFG /!;0
An image receptor was prepared by applying the mixture to Oji Yuka Co., Ltd. (Kishinhin) using a wire bar, drying it to a dry film thickness of 5 μm), and then heat-treating it in an oven at IOOO° C. for 3θ minutes.

Transfer recording The ink-coated surface of the above transfer sheet was placed on the recording medium and recorded using a thermal head under the following conditions, with a clear yellow color of /8
．． Two records of uniform color density were obtained.

Recording conditions: Linear density of main scanning and sub-scanning: 2 dots/width Recording power: 0. ,t! r”ii/dot head heating time 2/θm5ec Color density is measured using a densitometer TR manufactured by Macbeth, USA.
- Measured using a tack type.

A light resistance test of the obtained record was carried out using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63°C), but there was almost no discoloration or fading after EO waiting time irradiation. Ta. Furthermore, the transfer sheet and the recording were stable against heat and moisture, and had excellent storage stability in the dark.

Example λ The dyes shown in Table 1 were used instead of the dyes used in Example 1, and the ink was prepared, the transfer sheet was prepared, and the transfer recording was carried out in the same manner as in Example. The results are shown in Table 1. We were able to obtain a record of the clear yellow color of the tombstone.

The results of the light fastness test of the obtained record and the dark storage stability test of the transfer sheet/record were good.

Measured value in No. 1 No. * Acetone (Keyaki medium effect of the invention) Since the pyrazolone azo dye shown in [I] above used in the heat-sensitive transfer sheet of the present invention has a clear yellow color, an appropriate It is suitable for obtaining full-color recording with good color reproducibility by combining with magenta and cyan colors, and it is easy to sublimate and has a very low molecular extinction coefficient, so it does not place a large burden on the thermal head. Records with high color density can be obtained at high speed. Furthermore, heat, light, humidity,
Because it is stable against chemicals, it does not undergo thermal decomposition during transfer recording, and the resulting ink is good, making it easy to prepare uniformly dissolved and highly concentrated inks. By using this method, it is possible to obtain a heat-sensitive transfer sheet coated with a dye uniformly and at a high concentration. There are also no health and safety issues. Therefore, by using these heat-sensitive transfer sheets, recording with good uniformity and color density can be obtained.

Furthermore, the heat-sensitive transfer sheet of the present invention can utilize not only a heat-sensitive head but also infrared rays, laser light, etc. as a heating means.

Patent applicant: Mitsubishi Chemical Industries, Ltd. Representative patent attorney for long diameter - (1 other person)

Claims (1)

[Claims] (1) Apply the following general formula [I]▲ on the base film,
There are chemical formulas, tables, etc. , a furfuryl group, an optionally substituted allyloxyalkyl group, or an optionally substituted aryloxyalkyl group). sheet.