JP2929386B2 - Dye for thermal transfer recording - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a yellow dye and a magenta dye for thermal transfer recording, and more specifically, useful transferability, coloring property, and various fastnesses in a sublimation type thermal transfer recording method. It is an object of the present invention to provide clear yellow and magenta dyes having excellent properties and a thermal transfer sheet containing the dyes.

(Prior Art) At present, one of methods for obtaining a hard copy from a transient image such as a television, a video, and a still video camera is a sublimation type thermal transfer recording system.

In this method, a dye is sublimated by heat to form an image on a recording medium, and a heating element or a semiconductor laser is used as a heat source. By changing the energy applied to the heat source, the amount of dye sublimation transfer can be controlled, and an image with good gradation can be obtained. Therefore, this method is considered to be particularly advantageous for pictorial color printing.

(Problems to be Solved by the Invention) When a full-color image is obtained by the subtractive color method, the three primary colors that are the basics of hue expression are yellow, magenta, and cyan. Among them, yellow is a complementary color of blue, it is clear yellow, and its maximum absorption wavelength is required to be 420 to 480 nm, and magenta is a complementary color of green, which is clear red purple, and its maximum absorption wavelength is Is required to be 520 to 580 nm. The yellow and magenta disperse dyes currently used for sublimation-type thermal transfer recording have insufficient saturation, and color images with excellent color reproducibility cannot be obtained. Also, with the recent progress in recording methods, high-speed recording materials capable of providing clear images with sufficient density at low energy have been desired, but the disperse dyes currently used are also satisfactory in this regard. Does not have good performance.

In view of this situation, the present invention has been studied as a result of intensive studies to solve the problems of the prior art, and as a result, the benzoazole-based dye has extremely excellent transferability, and also exhibits a clear yellow or magenta color, and a cyan dye. Have been found to exhibit excellent color reproducibility when they are mixed with, and the present invention has been completed.

(Means for Solving the Problems) That is, the present invention relates to the general formula (1) (Wherein R ₁ is a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, aryl group, or X
Represents an atom or an atomic group forming a 5- or 6-membered ring together with R ₂ , and R ₂ represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group. Note that R ₁ and R ₂ are a 5-membered ring or a 6-membered ring which may contain an oxygen atom or a nitrogen atom.
A member ring may be formed. R ₃ is a hydrogen atom, a halogen atom,
A cyano group, an optionally substituted alkyl group, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group,
Represents an acyl group, an acylamino group, a sulfonylamino group, a ureido group, a carbamoyl group, a sulfamoyl group, or an amino group. R ₄ is a hydrogen atom, a halogen atom, a cyano group, a nitro group, an optionally substituted alkyl group, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group, a heterocycle, an acyl group, a sulfonyl group, an acylamino group , A sulfonylamino group, a ureido group, a carbamoyl group, a sulfamoyl group, and an amino group. Y represents an aromatic hydrocarbon ring, a 5- or 6-membered nitrogen-containing heterocyclic ring having 1 to 3 nitrogen atoms, and A represents an electron-withdrawing group. X represents a hydrogen atom or an atom or an atomic group which forms a 5- or 6-membered ring with R ₁ . Z represents a nitrogen atom or a methine group, and m and n represent 1 or 2. ) Comprising a dye for thermal transfer recording, a base sheet, and a dye-supporting layer formed on one surface of the base sheet, wherein the dye contained in the dye-supporting layer is represented by the general formula (1).
A thermal transfer sheet characterized by being a dye represented by the formula:

The dye represented by the general formula (1) can be obtained by a known method, for example, a benzoazole compound represented by the general formula (2) and a nitroso compound represented by the general formula (3) or a general formula (4) according to the following reaction formula. It can be easily produced by subjecting the indicated aldehyde compound to dehydration condensation in the presence of an acid, base or acid-base catalyst.

(Wherein, R ₁ , R ₂ , R ₃ , R ₄ , A, X, Y and m all have the above-mentioned meanings.) R ₁ shown in the general formula (1) is a methyl group; an ethyl group Alkyl groups such as methoxy, propyl and butyl groups; alkoxyalkyl groups such as methoxyethyl group and ethoxyethyl group;
Hydroxyalkyl groups such as hydroxyethyl group and β-hydroxypropyl group; halogenoalkyl groups such as chloroethyl group; cyanoalkyl groups such as cyanomethyl group and cyanoethyl group; cycloalkyl groups such as cyclohexane group; aralkyl groups such as benzyl group and phenethyl group. Group: an aryl group such as a phenyl group, a tolyl group, a halogenophenyl group and an alkoxyphenyl group, or an atom forming a 5- or 6-membered ring together with X. R ₂ is an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group; an alkoxyalkyl group such as a methoxyethyl group or an ethoxyethyl group; a hydroxyalkyl group such as a hydroxyethyl group or a β-hydroxypropyl group; A cyanoalkyl group such as a cyanomethyl group and a cyanoethyl group; a cycloalkyl group such as a cyclohexane group; an aralkyl group such as a benzyl group and a phenethyl group; an aryl such as a phenyl group, a tolyl group, a halogenophenyl group, and an alkoxyphenyl group Groups. In addition,
R ₁ and R ₂ may form a 5- or 6-membered ring which may contain an oxygen, nitrogen or sulfur atom.

R ₃ is a hydrogen atom; a halogen atom such as chlorine, bromine and iodine;
Cyano group; alkyl group such as methyl group, ethyl group, propyl group and butyl group; alkoxyalkyl group such as methoxyethyl group and ethoxyethyl group; hydroxyethyl group, β-
A hydroxyalkyl group such as a hydroxypropyl group; a halogenoalkyl group such as a chloroethyl group; a cyanomethyl group;
A cyanoalkyl group such as a cyanoethyl group; a cycloalkyl group such as a cyclohexane group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group; an aralkyl group such as a benzyl group and a phenethyl group; a phenyl group, a tolyl group, and a halogenophenyl Carboxyl group; acyl group such as acetyl group, propanoyl group and benzoyl group; acylamino group such as acetylamino group and benzoylamino group; methanesulfonylamino group, ethanesulfonylamino group and benzenesulfonylamino A sulphonylamino group such as a group; a ureido group such as a methylureido group, a 1,3-dimethylureido group or an ethylureide group; a carbamoyl group such as a methylcarbamoyl group, an ethylcarbamoyl group, or a phenylcarbamoyl group;
Sulfamoyl groups such as methylsulfamoyl group, ethylsulfamoyl group and phenylsulfamoyl group; and amino groups such as methylamino group, ethylamino group, propylamino group, dimethylamino group and diethylamino group.

R ₄ is a hydrogen atom; a halogen atom such as chlorine, bromine, and iodine;
Cyano group; nitro group; methyl group, ethyl group propyl group,
Alkyl groups such as butyl groups; alkoxyalkyl groups such as methoxyethyl groups and ethoxyethyl groups; hydroxyalkyl groups such as hydroxyethyl groups and β-hydroxypropyl groups; halogenoalkyl groups such as chloroethyl groups; and cyanomethyl groups and cyanoethyl groups. Cyanoalkyl group; cycloalkyl group such as cyclohexane group; alkoxy group such as methoxy group, ethoxy group, propoxy group, butoxy group; aralkyl group such as benzyl group, phenethyl group; phenyl group, tolyl group, halogenophenyl group, alkoxyphenyl Aryl groups such as groups; furyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl,
Heterocyclic rings such as thiazolyl group and pyridyl group; acyl groups such as acetyl group, propanoyl group and benzoyl group; acylamino groups such as acetylamino group and benzoylamino group; methanesulfonylamino group, ethanesulfonylamino group and benzenesulfonylamino group Sulfonylamino group; ureido group such as methylureido group, 1,3-dimethylureido group, ethylureido group; carbamoyl group such as methylcarbamoyl group, ethylcarbamoyl group, phenylcarbamoyl group; methylsulfamoyl group, ethylsulfamoyl And a sulfamoyl group such as a phenylsulfamoyl group; and an amino group such as a methylamino group, an ethylamino group, a propylamino group, a dimethylamino group, and a diethylamino group.

Y is an aromatic hydrocarbon ring, 5 having 1 to 3 nitrogen atoms
Represents a 6- or 6-membered nitrogen-containing heterocyclic ring, for example, benzene,
Pyrrole, pyrazole, imidazole, oxazole,
Thiazole, urea, pyridine, pyridazine, pyrimidine, pyrazine and the like.

A represents an electron withdrawing group, for example, a cyano group; a carboxyl group; an acyl group such as an acetyl group, a propanoyl group and a benzoyl group; an alkylsulfonyl group such as a methanesulfonyl group and an ethanesulfonyl group; a benzenesulfonyl group and a p-chlorophenylsulfonyl group An arylsulfonyl group;
Carbamoyl groups such as methylcarbamoyl group, ethylcarbamoyl group and phenylcarbamoyl group; sulfamoyl groups such as methylsulfamoyl group, ethylsulfamoyl group and phenylsulfamoyl group; methoxycarbonyl group, ethoxycarbonyl group and propoxycarbonyl group An alkoxycarbonyl group; a phenoxycarbonyl group,
and an aryloxycarbonyl group such as a p-methylphenoxycarbonyl group.

X represents a hydrogen atom or an atom or an atomic group that forms a 5- or 6-membered ring with R ₁ .

Z represents a nitrogen atom or a methine group, and m and n are 1
Or 2 is represented.

Preferred specific examples of the dye represented by formula (1) used in the present invention are shown below.

As a method of producing a thermal transfer recording ink using the dye of the present invention, there is a method of dissolving or atomizing the dye in a solvent with a suitable binder using a ball mill or the like to obtain an ink. As a binder, epoxy resin, phenol resin, urethane resin, acrylic resin, silicone resin, cellulose resin, polyvinyl chloride, polyethylene,
Examples include polystyrene, polycarbonate, polyester, polyimide, polyvinyl butyral, gum arabic, and casein. Examples of the solvent include water, alcohols such as methanol, ethanol, propanol, and butanol; aromatic hydrocarbons such as toluene, xylene and monochlorobenzene; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; dichloroethane; trichloroethylene; Examples include hydrogen halides such as ethylene, esters such as ethyl acetate and butyl acetate, and cellosolves such as methyl cellosolve and ethyl cellosolve.

As a transfer method, the ink obtained above is applied to an appropriate substrate using a bar coater to prepare a transfer sheet, the sheet is overlaid on a recording medium, and then heated from the back of the sheet with a heating element or the like. In this case, the dye on the sheet is transferred onto the recording medium. As the transfer substrate, generally, a capacitor paper, a cellophane paper, or a plastic film having good heat resistance such as a polyimide resin or a polyester resin is suitable. As the recording medium, plain paper can be used, but in order to enhance color development sensitivity, paper coated with polyester resin or polyamide resin, or synthetic paper such as polypropylene, polyvinyl chloride or polyester is used. You.

Since the dye of the present invention is a clear yellow or magenta color, for example, the following structural formula It is suitable for obtaining a full color in combination with the cyan dye represented by.

(Effects of the Invention) According to the present invention, a vivid yellow or magenta thermal transfer recording can be obtained by using a benzoazole dye represented by the general formula (1) and having good transferability.

Hereinafter, the present invention will be described specifically with reference to examples, but the examples do not limit the present invention.

Example 1 (1) Production of dye 5.0 g of 2-benzimidazolylacetonitrile was dissolved in 100 ml of ethanol and 200 ml of ethyl acetate, 27.2 g of sodium carbonate dissolved in 200 ml of water was added, and then N, N- dissolved in 45 ml of water was added. 8.5 g of diethyl-3-methyl-p-phenylenediamine hydrochloride were added. To this, 49.4 g of ammonium persulfate dissolved in 200 ml of water was added dropwise at room temperature, and reacted for 1.5 hours after completion of the addition. After the reaction was completed, the precipitated crystals were filtered to obtain 6.5 g of crude crystals. The obtained crude crystals were recrystallized from isopropyl alcohol to obtain 5.5 g of 1- (4'-diethylamino-2'-methyl-phenylimino) -1-benzimidazolyl-acetonitrile (yield: 52%). Melting point
271-272 ° C The maximum absorption wavelength (ethyl acetate) of this product was 497 nm.

(2) Preparation of thermal transfer sheet and transfer material The ink composition of 3 parts of the dye, 7 parts of polyvinyl butyral resin, 45 parts of methyl ethyl ketone, and 45 parts of toluene obtained in the above (1) is sufficiently kneaded with a ball mill, and A 6 μm-thick polyethylene terephthalate film subjected to heat treatment was applied using a bar coater so that the dry application amount was 1.0 g / m ² , and dried to obtain a thermal transfer sheet of the present invention.

Next, 14 parts of polyester resin, 43
Parts, and 43 parts of toluene, were applied to a synthetic paper as a base sheet at a rate of 10.0 g / m ² when dried, and dried to obtain a transfer-receiving material.

(3) Transfer Recording The thermal transfer sheet of the present invention and the material to be transferred are opposed to each other, and recording is performed by heating from the back surface of the transfer sheet using a thermal head to obtain a clear magenta high color density record. Was done. The recording density (OD) was 1.32.

Examples 2 to 19 Thereafter, the dyes shown in Table 1 were synthesized in the same manner as in Example 1, and each of them was subjected to thermal transfer to obtain a clear yellow or magenta color record having a high color density.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-216994 (JP, A) JP-A-4-4190 (JP, A) European publication 444327 (EP, A1) (58) Fields surveyed (Int .Cl. ⁶ , DB name) B41M 5/38-5/40 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. The general formula (1) (Wherein R ₁ is a substituted or unsubstituted alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, or X 1
Represents an atom or an atomic group forming a 5- or 6-membered ring together with R ₂ , and R ₂ represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group. Note that R ₁ and R ₂ are a 5-membered ring or a 6-membered ring which may contain an oxygen atom or a nitrogen atom.
A member ring may be formed. R ₃ is a hydrogen atom, a halogen atom,
A cyano group, an optionally substituted alkyl group, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group,
Represents an acyl group, an acylamino group, a sulfonylamino group, a ureido group, a carbamoyl group, a sulfamoyl group, or an amino group. R ₄ is a hydrogen atom, a halogen atom, a cyano group, a nitro group, an optionally substituted alkyl group, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group, a heterocycle, an acyl group, a sulfonyl group, an acylamino group , A sulfonylamino group, a ureido group, an alvamoyl group, a sulfamoyl group, and an amino group. Y represents an aromatic hydrocarbon ring, a 5- or 6-membered nitrogen-containing heterocyclic ring having 1 to 3 nitrogen atoms, and A represents an atom-attracting group. X represents a hydrogen atom or an atom or an atomic group which forms a 5- or 6-membered ring with R ₁ . Z represents a nitrogen atom or a methine group, and m and n represent 1 or 2. ) A dye for thermal transfer recording represented by. 2. A dye comprising a base sheet and a dye-supporting layer formed on one surface of the base sheet, wherein the dye contained in the dye-supporting layer is a dye represented by the following general formula (I): A thermal transfer sheet, characterized in that: (R ₁ or R ₂ in the above formula may be the same or different and represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, aryl group, and R ₁ and R ₂ are an oxygen atom or a nitrogen atom R ₃ may be a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, a cycloalkyl group, an alkoxy group, Represents an aralkyl group, an aryl group, an acyl group, an acylamino group, a sulfonylamino group, a ureido group, a carbamoyl group, a sulfamoyl group or an amino group, and R ₄ has a hydrogen atom, a halogen atom, a cyano group, a nitro group, and a substituent. Alkyl group, cycloalkyl group, alkoxy group, aralkyl group, aryl group, heterocyclic group, acyl group,
Sulfonyl group, acylamino group, sulfonylamino group,
Represents a ureido group, a carbamoyl group, a sulfamoyl group or an amino group, and X is a hydrogen atom or 5 together with R ₁
An atom or an atomic group forming a six-membered or six-membered ring,
Represents an aromatic hydrocarbon, a 5- or 6-membered nitrogen-containing heterocyclic ring having 1 to 3 nitrogen atoms, A represents an electron-withdrawing group,
Represents a nitrogen atom or a methine group, and m or n represents 1 or 2. )