JPH0742410B2 - Thermal sublimation transfer recording sheet - Google Patents

Description

[Detailed Description of the Invention] Industrial application TV, CRT color display, color facsimile,
The present invention relates to a thermal sublimation transfer recording sheet (hereinafter abbreviated as "transfer sheet") from which a color hard copy can be obtained from a magnetic camera or the like.

Problems to be Solved by the Prior Art and Invention As a cyan dye for thermal sublimation transfer recording, JP-A-59-
78894 has the following general formula (2) [In the formula, R and R ¹ represent a methyl group, an ethyl group, a linear or branched propyl group, or a butyl group. ], But the dye of the general formula (2) has a drawback of poor light resistance, which is a drawback in terms of storage of information records.

Further, JP-A-60-131294 describes the following general formula (3) [In the formula, R ¹ represents an alkyl group, R ² represents an alkenyl group,
Alkenyloxyalkyl group, alkoxyalkyl group,
It represents an alkoxyalkoxyalkyl group, a hydroxyalkyl group, a hydroxyalkoxyalkyl group or a hydroxyalkylthioalkyl group. ] The anthraquinone dye represented by
This dye lacked the storage stability required as an information recording material. That is, if the recording sheets are piled up after recording, the recorded content is transferred to another recording sheet.

Means for Solving the Problems As a result of intensive studies, the inventors of the present invention have found a cyan dye having good light resistance, good storage stability, and good sublimation transfer, and completed the present invention.

That is, the present invention provides the following general formula (1) [In the formula (1), R ¹ represents a benzyl group or a cyclohexyl group, and R ² represents an alkyl group, a benzyl group, a phenyl group,
It represents a tolyl group, a 5- or 6-membered cycloalkyl group, an alkenyl group, an alkenyloxyalkyl group, an alkoxyalkyl group, a hydroxyalkyl group, or a hydroxyalkoxyalkyl group. ] A heat-sensitive sublimation transfer recording sheet having a base material coated with a heat-sensitive transfer recording ink containing a dye represented by the following.

In the formula (1), when R ¹ is a benzyl group or a cyclohexyl group, the transfer energy is small and it easily sublimes,
In addition, they have found the effects of preventing retransfer of recording and improving light fastness, and have reached the present invention.

In formula (1), R ² is a methyl group, an ethyl group, a linear or branched propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an alkyl group such as an octyl group; a benzyl group, Phenyl group; tolyl group; 5- or 6-membered cycloalkyl group; alkenyl group such as allyl group, 2-methylallyl group, 3-methylallyl group, 2-bromoallyl group; allyloxyethyl group, 2-methylallyloxyethyl group, etc. Alkenyloxyalkyl groups; alkoxyalkyl groups such as methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, 3-methoxybutyl group; hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4 -Hydroxybutyl group, 3-hydroxybutyl group, 5-hydroxypentyl group, 3-hydroxy-2,
Examples thereof include hydroxyalkyl groups such as 2-dimethylpropyl group, 3-hydroxy-2,2-diethylpropyl group and 6-hydroxyheptyl group; and hydroxyalkoxyalkyl groups such as hydroxyethoxyethyl group.

The dye represented by the formula (1) can be synthesized by the known method by the following structural formula. [In the formula, R ² has the same meaning as in formula (1). ] Is chlorinated with thionyl chloride, and then benzyl alcohol or
Obtained by reacting with cyclohexyl alcohol.

As a method for producing a thermal transfer recording ink using this dye, the dye may be mixed with an appropriate resin solvent, water or the like to prepare the recording ink. As a thermal transfer method,
Examples of the method include applying the ink obtained above onto a suitable substrate to form a transfer sheet, superposing the sheet on a recording medium, and then heating and pressurizing from the backside of the sheet with a thermal recording head. By doing so, 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, such as rosin type, phenol type, xylene type, petroleum type, polysulfone type, vinyl type, polyamide type, alkyd type, nitrocellulose. Oily resins such as resins, alkyl celluloses, etc., or aqueous resins such as maleic acid, acrylic acid, casein, sierra, and glue can be used. As a solvent for ink preparation, alcohols such as methanol, ethanol, propanol and butanol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as benzene, toluene and xylene, ethyl acetate,
Esters such as butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, hydrocarbons such as ligroin, cyclohexane and kerosene, dimethylformamide, etc. can be used. It is also possible to mix and use the above solvents.

As the base material for applying ink, thin paper such as condenser paper and glassine paper, and plastic film with good heat resistance such as polyester, polyamide, and polyimide are suitable, but these base materials are suitable for thermal recording heads. In order to improve heat transfer efficiency to the dye, a thickness of about 5 to 50 μm is suitable.

As the recording medium, plain paper can be used, but a resin having good compatibility with the dye in order to improve coloring of the dye, or a resin obtained by adding acidic fine particles such as silica gel to the plain paper is used. Coated with, impregnated with, or laminated with resin film,
By using a special processed paper that has been acetylated, good recording with excellent image stability under high temperature and high humidity can be performed. It is also possible to use films of various resins or synthetic papers made from them.

Further, after transfer recording, for example, a polyester film may be hot-pressed and laminated on the transfer recorded image to improve the color development of the dye and to stabilize the storage of the recording.

Examples Hereinafter, examples will be described.

[Example-1] i) Production of dye Compound shown by 10.8 g, chlorobenzene 62 g, pyridine
A mixture of 1 g and thionyl chloride 6.5 g was stirred at 80 ° C. for 2 hours. Then, after removing excess thiotyl chloride under reduced pressure,
30 g of cyclohexanol was added, and the mixture was stirred at 90 ° C for 3 hours. After cooling to room temperature, 300 ml of methanol was added, the precipitated crystals were collected, washed with water and dried to obtain 11.5 g of a dye represented by the following structural formula.

The maximum absorption wavelength (λma of this dye in chloroform
x) was 674 nm and showed a parent ion peak at m / e = 378 in the mass spectrum.

ii) Method for preparing the ink 2 g of the dye obtained in the above i) 2 g Ethyl cellulose 8 g Isopropanol 90 g Total 100 g The ink is prepared by mixing the dye mixture having the above composition for about 30 minutes with a paint conditioner using glass beads. Was prepared.

iii) Method for preparing transfer sheet Using a gravure proofing machine (plate depth 30 μm), the above ink was applied to capacitor paper (10 μm thick).

iv) Method for preparing image-receiving paper 10 g of an aqueous dispersion of 34% by weight saturated polyester (manufactured by Toyobo Co., Ltd., Pyronal MD-1200) and 10 g of silica gel (Nippsil E200A manufactured by Nippon Silica Co., Ltd.) were mixed, and the prepared paint was used as a fine paper. Percoater (PK Print)
Coat Instruments Co. No. 1) was used for coating.

v) Transfer recording method The ink application surface of the transfer sheet is overlaid on the image receiving paper paint application surface, and thermal transfer recording is performed using a thermal head having a heating resistor of 250Ω at a density of 4 dots / mm to obtain a color density of 0.95. A cyan record was obtained. At this time, a voltage of 18V was applied to the thermal head for 6 milliseconds.

The color density is the densitometer RD manufactured by Macbeth Co.
It was measured using a -514 type (filter: Ratten No. 58).

The color density was calculated by the following formula.

Color density = log ₁₀ (Io / I) Io: Intensity of light reflected from a standard white reflector I: Intensity of light reflected from a test object In addition, a light resistance test of the obtained record was performed using a xenon fade meter ( Suga Test Instruments Co., Ltd.) was used at a black panel temperature of 63 ± 2 ° C., but it was not discolored by irradiation for 40 hours, and the image stability under high temperature and high humidity was excellent.

In addition, there was no color transfer even when it was placed at 40 ° C for 100 hours on an unrecorded image receiving paper.

[Example-2] Instead of the dye used in Example-1, the following formula (4) Using 2 g of the dye represented by the following method, an ink is prepared, a transfer sheet is prepared, an image-receiving paper is prepared and transfer recording is carried out in the same manner as in Example-1, and the cyan color having a color density of 0.97 is excellent in light fastness and at high temperature and A record excellent in stability under high humidity was obtained.

The above dye was obtained by the same method as in the dye of Example 1 except that benzyl alcohol was used instead of cyclohexyl alcohol.
Synthesized by using 25 g.

Maximum absorption wavelength of dye (4) in chloroform (λma
x) was 673 nm.

[Example-3] i) Method of preparing ink 2 g of dye of the following formula (5) acrylic acid resin (manufactured by Mitsubishi Rayon Co., Ltd., Dyanol BR-107 trade name) 8 g ethanol 45 g water 45 g total 100 g An ink was prepared by mixing the dye mixture having the above composition with a glass beads using a paint conditioner for about 30 minutes.

ii) Method for preparing transfer sheet Using the gravure proofing machine used in Example-1, the above ink was applied to glassine paper (10 μm thick).

iii) Transfer recording method The ink-coated surface of the transfer sheet was overlaid on a high-quality paper laminated with a polyester film (10 μm thick), and
Recording was performed under the same conditions using the thermosensitive recording head used in No. 1, and as a result, a cyan color having a color density of 0.90 was excellent in light fastness and stable in high temperature and high humidity.

The above dye was obtained by the same method as the dye of Example 1 Instead of the compound shown by It was synthesized by using 13.5 g of the compound represented by.

Maximum absorption wavelength of compound (5) in chloroform (λ
max) was 672 nm.

[Example-4] Instead of the dye used in Example-1, the following formula (6) was used. Using 2 g of the dye represented by the following, in the same manner as in Example-1, adjustment of ink, preparation of transfer sheet, preparation of image receiving paper,
Also, transfer recording was carried out to obtain a recording excellent in light resistance of cyan color having a color density of 0.85 and stability under high temperature and high humidity.

The above dye was obtained by the same method as the dye of Example 1 Instead of the compound shown by By using 13.5 g of the compound represented by
It was synthesized by using 25 g of benzyl alcohol instead of cyclohexyl alcohol.

Maximum absorption wavelength of compound (6) in chloroform (λ
max) was 674 nm.

[Example-5] Ink preparation was carried out in the same manner as in Example-1, using the dyes 2g shown in Table ¹ for R ¹ and R ² of the general formula (1), respectively.
A transfer sheet and an image-receiving paper were prepared, and then transfer recording was carried out by the same method as in Example 1 to obtain cyan recording having the color density shown in Table 1. All of these records were tested for light resistance by the same method as in Example-1. As a result, the records showed almost no discoloration and excellent image stability under high temperature and high humidity.

The maximum absorption wavelength of each dye is also shown.

Claims (1)

[Claims] 1. A general formula (I) [In the formula (I), R ¹ represents a benzyl group or a cyclohexyl group, and R ² represents an alkyl group, a benzyl group, a phenyl group, a tolyl group, a 5- or 6-membered cycloalkyl group, an alkenyl group, an alkenyloxyalkyl group. , An alkoxyalkyl group, a hydroxyalkyl group, or a hydroxyalkoxyalkyl group. ] A heat-sensitive sublimation transfer recording sheet having a base material coated with a heat-sensitive transfer recording ink containing a dye represented by: