JPS6135993A - Transfer sheet - Google Patents

Abstract

PURPOSE:To enhance not only a transfer characteristic but also hue and fastness, in a thermal transfer sheet using a sublimable dye, by using a specific naphthoquinone dye together with a specific anthraquinone dye as sublimable dyes. CONSTITUTION:At least one of naphthoquinone dyes represented by formulae I, II(wherein R and R' are an 1-6C substituted or unsubstituted alkyl group or cycloalkyl group) and at least one of anthraquinone dyes represented formulae III, IV (wherein X is a cyano group or COOR' and R and R' are same as mentioned above) are used so as to be mixed in a range of 1:9-9:1 on a wt. ratio and dissolved or dispersed in a medium such as water or alcohole along with a binder such as a water soluble resin or acrylic resin to prepare ink which is, in turn, applied to a base film and dried to obtain a transfer sheet.

Description

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

(CI) Prior Art Currently, color recording technologies using electrophotography, 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.

Fi to thermal transfer method, onto base film.

A melting method in which a wet transfer sheet is heated by a thermal head to form a heat-melting ink layer, and the ink is melted in the ink and transferred onto the recording medium, and the base film contains a sublimable dye. The transfer sheet, on which a color material layer has been formed, is heated by a thermal head to sublimate the dye, and the dye is transferred onto the recording medium using the sublimation method. In addition, since the amount of sublimation of the dye can be controlled, one-gradation recording is easy, which is particularly advantageous for full-color recording.

In order to obtain a full-color record using sublimation type thermal transfer recording, it is sufficient to use yellow, magenta, and cyan transfer sheets and perform transfer recording in sequence. , using a naphthoquinone dye represented by the following general formula (1) or Fi(I).

There are those using an anthraquinone dye represented by the following general formula (II) or (, W) (Japanese Patent Application Laid-Open No. 2003-110002, Shoj Turf 1rr?, etc.).

E→ Problems to be Solved by the Invention Conventional cyan transfer sheets using the dyes represented by the above general formulas (1), (Ill, Excellent) and (Transfer) alone have the following problems:
Although the color tone and fastness were excellent, the following problems occurred in transfer characteristics.

That is, the naphthoquinone dyes represented by general formulas (1) and (II) have high sensitivity to heat, and even when the energy given to the thermal head is low and 6, the sublimation property is good, and as the energy increases, The color density also increases, but if high □ energy is applied, one dye partially decomposes thermally, making it impossible to obtain sufficient color density9, and the color density cannot be increased even if the energy is further increased. .

In addition, anthraquinone dyes represented by the general formulas (fill and (trans)) do not decompose even when high energy is applied to them, and sublime in light, making it possible to obtain a high color am. is insufficient, it is not possible to obtain sufficient color density, and even if the energy is increased, the color density cannot be increased very much.

OBJECTIVE OF THE INVENTION The object of the present invention is to provide a cyan color sheet which has good transfer characteristics and provides recordings with good color tone and fastness.

Structure of the Invention A) Means for Solving Problems The present invention is a thermal transfer method in which a transfer sheet coated with a sublimable dye is heated by a thermal head to transfer the sublimable dye onto a recording medium to obtain a record. A transfer sheet used in the recording method, wherein the sublimable dye is the following general Niyama or (fl) R'HN O (wherein R and R1 are 01 to C8 substituted or unsubstituted alkyl groups or cycloalkyl At least 7 types of naphthoquinone dyes represented by the following general formula (representing a group)) and (in the formula, X is a cyano group or 0OOR'
represents the base.

The gist of the present invention is a transfer sheet comprising at least one of the anthraquinone dyes represented by (R and R1 have the same meanings as defined above).

In the general formula (1), (Ml, @ and decoy, R and R
Examples of 1 include alkyl groups such as methyl, ethyl, propyl, and butyl groups, alkoxyalkyl groups, hydroxyalkyl groups, β-chloroethyl groups, β-cyanoethyl groups, β-phenoxyethyl groups, allyl groups, and benzyl groups.

Examples include substituted alkyl groups such as β-phenylethyl group and tetrahtomifurfuryl group, and cycloalkyl groups such as cyclohexyl group.

Further, the alkyl group, substituted alkyl group, and cycloalkyl group of R and R1 are preferably 01 to 0 $, since if the number of carbon atoms is too large and the sublimation property of the dye decreases.

What are the above naphthoquinone dyes and 7-nthraquinone dyes?1
They can be mixed and used in a weight ratio of 1:9' to 1:1.

The transfer sheet is made by dissolving or dispersing the above-mentioned dye in the form of fine particles in a medium together with a binder.

It is obtained by preparing an ink, applying the ink onto a base film, and drying it.

Binders for ink preparation include water-soluble resins such as cellulose, acrylic, and starch, acrylic resins, and methacrylic resins.

Examples include resin masses soluble in organic solvents such as polystyrene, polycarbonate, polysulfone, polyethersulfone, and ethyl cellulose. In the case of an organic solvent-soluble resin, it is possible to use it not only as an organic solvent solution but also in the form of an aqueous dispersion.

In addition to water, alcohols such as methyl alcohol, isopropyl alcohol, and isobutyl alcohol can be used as a medium for preparing ink.

Methyl cellosolve, ethyl cellosolve, etc. Which cellosolves, toluene, l? Aromatics such as silene and chlorobenzene, esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone,
Ketones such as cyclohexanone, chlorinated solvents such as methylene chloride, chloroform, and trichloroethylene, ethers such as tetrahydrofuran and dioxane, N,
Examples include organic solvents such as 11-dimethylformamide and M-methylpyrrolidone.

Suitable base films for applying ink for making transfer sheets include condenser paper, thin paper such as glassine paper, and plastic films with good heat resistance such as polyester, polyamide, and polyimide.
Their thickness may range from 3 to j Opm.

The ink can be applied to the base film using a reverse roll coater, a gravure coater, a rod coater, or an air doctor coater (Yuji Harasaki, "Coating Method J", Maki Shoten).

Effects of the Invention When the transfer sheet of the present invention is used, even if the energy applied to the thermal head is low, it is possible to obtain almost the same color density as a transfer sheet containing a monotonon dye alone, and the energy is high. Therefore, when high energy is applied, the color density is slightly lower than that of a transfer sheet containing only anthraquinone dye, but as the energy increases, the color density also increases.] Sufficient color density can be obtained. It will be done.

Furthermore, in terms of color tone and fastness, it is as excellent as the above-mentioned single transfer sheet.

Example The present invention will be specifically explained in the following examples.

Examples 1 to 7 and comparative examples/, e #g, the following 1st
Captomunon pigments shown in the table 7. j and anthraquinone dye7. j t (however, in the comparative example, dye 1jf), polycarbonate resin (manufactured by Mitsubishi Kasei Corporation, Tubarex 70λJA, trade name) tjy and methylene chloride 7υV were mixed with paint conditioner for 10 minutes.
The ink was prepared by processing for a minute.

This ink was applied to a polyimide film (/!pm thickness) using a bar coater (wet film thickness 1 μm) and dried to obtain a transfer sheet.

The ink-coated surface of this transfer sheet was overlapped with the recording medium and recording was performed using a thermal head under the following recording conditions to obtain recordings with the color densities shown in Table 7.

Recording conditions: Main scanning and sub-scanning latitudinal density = μdots/w recording power
: 0. tN/dot head heating time: ,2. a, t, r and no 0m5
ec.

The recording medium was an aqueous dispersion of a saturated polyester resin (manufactured by Toyobo Co., Ltd., Pyronal MD-/
200. Mix silica (manufactured by Nippon Silikani Gyo Co., Ltd., N1 psilEλ20, product name) it, and apply the prepared solution to art paper (toopm thickness) using a bar coater (wet film thickness: μm). Manufactured by coating and drying.

Pigment used in the test: OHHOH@ONHCH@1st color density is Densitometer RD, manufactured by Macbeth, USA.
-Measurement was made using a filter (filter: Wratten). All the records obtained showed a clear cyan color.

Also, there is a carbon arc fade meter (not available).

Further, under conditions of a temperature of 60°C and humidity of 0.

Storage stability under high temperature and high humidity We conducted a commercial sale, but the transfer record did not change color or fade even after 3 days.

For reference, the results of Example 1, Comparative Example 1, and Comparative Example 7 in Table 7 are shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a graph showing the results of Example 1, Comparative Example 1, and Comparative Example 7 in Table 1, and shows the results of Example 1, Comparative Example 1, and Comparative Example 7.
Comparative Example No-Δ-1Δ--: Comparative Example 7 is shown. Applicant: Mitsubishi Chemical Industries, Ltd. Agent: Patent attorney: Yo Hase - Compiled by 1 other person 1.

Claims (1)

[Claims] (1) A transfer sheet used in a thermal transfer recording method in which a transfer sheet coated with a sublimable dye is heated by a thermal head to transfer the sublimable dye to a recording medium to obtain a record, the transfer sheet being coated with a sublimable dye. The following general formula (I) or (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼......(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼......(II) (In the formula, R and R^ 1 represents a substituted or unsubstituted alkyl group or cycloalkyl group of C_1 to C_3) and at least one naphthoquinone dye represented by the following general formula (III) or (IV) ▲ Numerical formula, chemical formula, table etc. ▼......(III) ▲Mathematical formulas, chemical formulas, tables, etc. ▼......(IV) (In the formula, X represents a cyano group or a COOR^1 group, and R
and R^1 represents the same meaning as above).