JPS6030391A - Naphthol coloring matter for thermal transfer recording - Google Patents

Abstract

PURPOSE:To obtain a coloring matter receiving no thermal decomposition under the working condition of a thermal recording head and having color phase pref. from the aspect of color reproducibility and large molecular extinction coefficient, by using a specific naphthol compound. CONSTITUTION:A naphthol compound represented by formula I (wherein formula IIis lower alkyl or lower alkoxy and R is lower alkyl or lower aryl) is used as coloring matter for thermal transfer recording. As the compound represented by the formula I , 2-phenylazo-4-methoxy-1-naphthol and 2-(4'-fluorophenylazo)-4- methoxy-1-naphthol are designated. In preparing ink for thermal transfer recording by using the aforementioned coloring matter, the coloring matter may be mixed with a proper resin, a solvent or water. As a base material to which the ink is applied, Indian paper such as condenser paper or glassine paper or a plastic film having good heat resistance comprising polyester or polyamide is suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a naphthol-based thermal transfer recording dye.

Currently, a sublimation type thermal transfer recording method has been proposed as a method for obtaining color hard copies from televisions, CRT color displays, color facsimile machines, magnetic cameras, etc. This method uses a transfer sheet coated with a sublimable dye to a thermal recording head. This is a method of sublimating and transferring the dye to the recording medium by heating it with a heat-sensitive head to obtain color recording, but it is easy to express gradation because the amount of sublimation of the dye can be controlled by adjusting the energy applied to the thermal head. Compared to other recording methods, it is particularly advantageous in obtaining full-color hard copies.

By the way, the dye used in this recording method must meet the following conditions.

■ 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.

■ High molecular extinction coefficient.

■ Stable against light, moisture, chemicals, etc.

■ Easy to synthesize.

Conventionally, dyes for transfer printing of polyester fibers have been mainly considered for this recording method, but dyes that satisfy the above conditions,
There are almost no products that can be put to practical use, and solid recording with sufficient color density cannot be obtained. The purpose of this invention is to provide a magenta color pigment that is

That is, the present invention has the following general formula CI') H R (wherein 6F represents a lower alkyl group, a lower alkoxy group, a trifluoromethyl group, or a phenyl group optionally substituted with a halogen atom, and R alkyl group,
Lower alkoxyal In the general formula (1), H is a lower alkyl group such as a methyl group, an ethyl group, an n-propyl group, a 1so-7'robyl group, an n-butyl group, a methoxy group,
Represents a lower alkoxy group such as an ethoxy group or n-butoxy group, a trifluoromethyl group, or a phenyl group that may be substituted with a halogen atom such as a chlorine atom or a bromine atom, and R is a methyl group, an ethyl group, or -propyl group, ts
Lower alkyl groups such as o-7'lopyl group and n-butyl group,
It represents a lower alkoxyalkyl group such as a methoxyethyl group, a methoxypropyl group, an ethoxyethyl group, or an allyl group.

Particularly preferred are dyes in which the moiety is a phenyl group, a lower alkyl group, or a phenyl group having a chlorine atom, and R is a lower alkyl group or an allyl group.

In addition, "lower" as used in the present invention refers to "7 to 7 carbon atoms".
means.

Specific examples of the dyes of the present invention include the following.

3-Cophenylazo-methoxy/-naphthol, 11-phenylazoterethoxy/-naphthol, Cophenylazo Q-(n)-propoxy-7-naphthol, Cophenylazo y-(day o)-Floboxy/
-naphthol, 2-phenylazo4'-(n)-butoxy-/-naphthol, cophenylazoter (iso) -7')xy/-naphthol, 2-phenylazoter (β'-methoxyethyl)- 7
-Naphthol, 2-phenylazoter (γ'-methoxypropyl)-
/-su7toll, 2-(2'-methylphenylazo)-termethoxy-/
-Naphthol, 2-(2'-methylphenylazo)-gu(1θ0)-
Propoxy-/-naphthol, 4-2-(3'-methylphenylazo)-termethoxy-7
-naphthol, 2-(3'-methylphenylazo)-ter(1θO)-
Prozexy-l-naphthol, 2-(lI'-methylphenylazo)-termethoxy-
/-naphthol, x-(II'-methylphenylazo)-di-1-doxyl-naphthol, Co(γ'-methylphenylazo)-gu(1sO)-
Propoxy-l-7tol, co(II'-ethylphenylazo)-termethoxy-
/-naphthol, 2-(2', ri'-dimethylphenylazo)-+-methoxy-/-naphthol, 2-(λ', ri'-dimethylphenylazo)-ter(1
-o)-propoxy-/-su7toll,! -(J'-
methoxyphenylazo)-l-methoxy/-su7tol, s-(y'-methoxyphenylazo)-termethoxy-/-su7tol, 5-(41'-ethoxyphenylazo)-termethoxy-/-naphthol, u-(2'-)lifluoromethylphenylazo)-coumethoxy-l-naphthol, -1(j'-)IJfluoromethylphenylazo)
-II-(iao)-propoxy-naphthol,! −
(,,7'-)Lifluoromethylphenylazo)-termethoxy-7-naphthol 1. 2-(4/'-)lifluoromethylphenylazo)-
termethoxy/-naphthol, -1(λ'-chlorophenylazo)-l-methoxy-/
- Naphthol, ! -(3'-chlorophenylazo)-l-methoxy-l
-naphthol, 2-(ll1-chlorophenylazo) -l-methoxy-/-naphthol, s -(,2'-fluorophenylazo)-y-methoxy-7-naphthol, λ-(3'-fluorophenylazo) -termethoxy-
l-naphthol, 2-(da'-fluorophenylazo)-9-methoxyl-naphthol, cuphenylazoterallyloxy/-naphthol, a-(s'-phenylazo)-couaryloxy-/
-naphthol, 2-(4I'-phenylazo)-guaryloxy-l
-naphthol, J-(,7'-)lifluoromethyl)-guaryloxy-l-naphthol.

Ni(3'-chlorophenylazo:/')-4'-allyloxy-/-naphthol, Cu(,7'-fluorophenylazo)-q-allyloxy-/-naphthol.

These pigments can be produced by known methods, such as
For example, an aniline represented by the following general formula [■] σNH, CII) (in the formula, 0Y represents the same meaning as in the above general formula [I]) is diazotized with one Fu in the following general formula Cl) It can be easily obtained by coupling with a naphthol represented by H R (wherein R has the same meaning as in the general formula CI).

As a method for producing a thermal transfer recording ink using the dye of the present invention, the dye may be mixed with a suitable resin, solvent, water, etc. to prepare the recording ink. In addition, as a thermal transfer method, the ink obtained above is applied onto a suitable base material to create a transfer sheet, the sheet is placed on the recording medium, and then heated and pressed from the back side of the sheet with a thermal recording head. In this way, the dye on the sheet is transferred onto the recording medium.

The resin for preparing the above ink may be one used in ordinary printing inks, including: 8-synyl, phenol, xylene, petroleum, 1, vinyl, polyamide, alkyd, Oil-based resins such as nitrocellulose, alkylcellulose, and alkylcelluloses, or water-based resins such as maleic acid, acrylic acid, casein, shunt, and glue can be used. In addition, as a solvent for ink lubrication, methanol,
Alcohols such as ethanol, propatool, and butanol; cellosolves such as methyl cellosolve and ethyl cellosolve; aromatics such as benzene, toluene, and xylene; esters such as ethyl acetate and butyl acetate; and ketones such as acetone, methyl ethyl ketone, and cyclohexanone. Hydrocarbons such as /, ligroin, cyclohexane, kerosene, and dimethylformua can be used with Doka etc.
When using an aqueous resin, water or a mixture of water and the above-mentioned solvents can be used.

Suitable substrates to which the ink is applied include thin paper such as condenser paper, glass/paper, and plastic films with good heat resistance such as polyester, polyamide, and polyimide.

These base materials suitably have a thickness of about 5 to go μm in order to improve the efficiency of heat transfer from the thermal recording head to the dye.

Ordinary paper can also be used as the recording medium, but in order to improve the color development of the dye, it may be coated or impregnated with a resin that has good compatibility with the dye, or it may be laminated with a resin film. Good recording can be achieved by using paper or special processed paper that has been treated with acetylation. It is also possible to use films of various resins or synthetic papers made from them.

Furthermore, by heat-pressing and laminating, for example, a polyester film on the transfer recording surface after transfer recording, it is possible to improve the color development of the dye and to stabilize the recording during storage.

Since the dye of the present invention has a vivid magenta color, for example, the yellow color complex represented by the following structural formula (3) and the following structural formula ONHCH
.

Suitable for obtaining full color in combination with cyan dyes shown in

The above yellow dye can be easily obtained by diazotization coupling of aniline to N-methyl-3-cyasodarmethyl-6-hydroxy-copylidone.

The above cyan dye can be obtained by reacting /-amino-carboxylated methylaminoanthraquinone with methanol in concentrated sulfuric acid.

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

Example/I) Preparation method of thermal transfer recording ink H The above dye -2y Ethyl cellulose ty Ingropanol 90y Total 1ooy The dye mixture having the above composition is mixed with a paint using glass beads; a conditioner for about 3 degrees. Specifically, the ink was prepared.

+1) Method for creating a transfer sheet The above ink was applied to a capacitor paper (10 μm) using a gravure proofing machine (plate depth 3θ μm).

12-111) Method for making image receiving paper An aqueous dispersion of saturated polyester 3'1% by weight (Pyronal MD-/, manufactured by Toyobo Co., Ltd., 20θ) 10F and calcium bicarbonate (Maruo Calcium Manufacturing Super/, 0%)
0)! Mix 50 g of fO weight water slurry and apply the prepared paint to high-quality paper (thickness 1008 m) using a bar coater (RK Pr1nt Coat Instrument).
It was applied using a flattener manufactured by S Company.

IV) Transfer Recording Method The ink-coated surface of the transfer sheet is overlapped with the paint-coated surface of the image-receiving paper, and thermal transfer recording is performed using a thermal head having a heating resistor of 2SθΩ at a density of dadot/gl, and the color density is adjusted. A magenta record of 〇 was obtained. At this time, an ITV voltage was applied to the thermal head for 6 milliseconds.

The color density was measured using Dentmeter R manufactured by Macbeth Co., Ltd. in the United States.
It was measured using a D-j/lI type (filter: Ratten Jatf).

Color density was calculated using the following formula.

Color density = JO#+o (IO/I) Process 0: Intensity of reflected light from standard white reflector I: Intensity of reflected light from test object In addition, the light resistance test of the obtained record was performed using carbon arc fade. The test was carried out using a meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature: 13 °C), but there was almost no discoloration after 1IO hours of irradiation.

Example 1 Using dye 1 shown in Table 1, in the same manner as in Example 1, preparation of ink, creation of transfer sheet and image receiving paper,
Transfer recording was performed to obtain magenta recordings with the color densities shown in Table 1.

All of these records showed almost no discoloration when tested for light resistance in the same manner as in Examples.

Table 1 Sender: Mitsubishi Chemical Industries, Ltd. Representative patent attorney required - Others/names

Claims (1)

[Claims] (1) General formula [■] 0■ R (In the formula, the symbol represents a lower alkyl group, a lower alkoxy group, a trifluoromethyl group, or a phenyl group which may be substituted with a halogen atom, and R is a lower alkyl group, A naphthol-based thermal transfer recording dye represented by a lower alkoxyalkyl group or an allyl group.