JPH0533158B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to an ink composition used for sublimation type heat-sensitive recording transfer materials, and in particular to an ink composition that can uniformly coat a coloring material layer containing a sublimable dye on a substrate. It is related to. Conventional structure and problems In the sublimation heat-sensitive recording method, a transfer sheet is coated with ink containing a sublimable dye on a substrate to form a coloring layer, and is heated by a thermal head to sublimate the dye and transfer it to the transfer sheet. It is recorded on the body, and by changing the energy given to the thermal head,
Since the amount of dye sublimation transfer can be controlled,
Gradation recording is easy and it is particularly advantageous for full color recording. The sublimable dye conventionally used in this recording method is
Dyes for transfer printing of polyester fibers, which have excellent stability, have been common, but because the dye has low sublimation properties, the coloring power is poor, and it is difficult to obtain sufficient color density with the thermal energy of a normal thermal head. Ta. In addition, although ionic dyes containing color formers with high sublimability can provide sufficient color density,
There was a problem with storage stability. The transfer sheet used in this recording method is prepared by preparing ink by dissolving or dispersing sublimable dye in various solvents with a binder, uniformly coating the ink on the substrate, and drying the solvent. It is something to do. However, nonionic dyes have low solubility in various solvents, and even those that are soluble often recrystallize on the transfer sheet due to drying of the solvent during coating. When transfer recording is performed using a transfer sheet in which dye has recrystallized, sublimation transfer may not be performed in accordance with the shape of the heating element, and transfer other than sublimation may occur due to unevenness on the sheet, resulting in color unevenness in the recorded image. This occurs and it is not possible to obtain good quality records. On the other hand, sublimable dyes are generally difficult to crush into fine particles, making it difficult to prepare fine particle dispersed inks. OBJECTS OF THE INVENTION An object of the present invention is to provide an ink composition for a thermal recording transfer material that uses a sublimable dye that is stable and has an excellent sublimation ability, and provides sufficient recording density and good image quality. Structure of the Invention At least one dye selected from among the sublimable dyes represented by the following general formulas (), (), and () and at least one of polysulfone, polyethersulfone, polycarbonate, polyphenylene oxide, or polyarylate is disposed on a substrate. The present invention relates to an ink composition for a thermal recording transfer material, which comprises one type of binder and at least one type of solvent selected from chlorinated solvents, brominated solvents, toluene, cyclohexanone, and 1,4-dioxane. (In the formula, X is a hydrogen atom or a methyl group, R and
R' represents a methyl group, an ethyl group, a linear or branched propyl group, or a butyl group, respectively). Description of Examples Specific examples of the sublimable dyes represented by the general formulas (), (), and () include the following. Those that emit a cyan color represented by (): 1,5-bis(methylamino)-4,8-naphthoquinone, 1,5-bis(ethylamino)-4,
8-naphthoquinone, 1,5-bis((n)-propylamino)-4,8-naphthoquinone, 1,5-bis((iso)-propylamino)-4,8-naphthoquinone, 1,5-bis( (n)-butylamino)-4,8
-naphthoquinone, 1,5-bis((iso)-propylamino)-4,8-naphthoquinone, 1-methylamino-5-ethylamino-4,8-naphthoquinone, 1-methylamino-5-(n)- Propylamino-4,8-naphthoquinone, 1-methylamino-5
-(n)-butylamino-4,8-naphthoquinone, 1
-Methylamino-5-(iso)-propylamino-
4,8-naphthoquinone, 1-ethylamino-5-
(n)-Propylamino-4,8-naphthoquinone, 1
-ethylamino-5-(n)-butylamino-4,8
-naphthoquinone, 1-(n)-propylamino-5-
(n)-Butylamino-4,8-naphthoquinone. Those that give off a yellow color represented by (): 4-(2,2-dicyanovinyl)-N,N-dimethylaniline, 4-(2,2-dicyanovinyl)-
N,N-diethylaniline, 4-(2,2-dicyanovinyl)-N,N-di(n)-propylaniline,
4-(2,2-dicyanovinyl)-N,N-di(iso)-propylaniline, 4-(2,2-dicyanovinyl)-N,N-di(n)-butylaniline, 4
-(2,2-dicyanovinyl)-N,N-di(iso)
-butylaniline, 4-(2,2-dicyanovinyl)-N,N-di(sec)-butylaniline, 3-
Methyl-4-(2,2-dicyanovinyl)-N,N
-dimethylaniline, 3-methyl-4-(2,2
-dicyanovinyl)-N,N-diethylaniline,
3-Methyl-4-(2,2-dicyanovinyl)-
N,N-di(n)-propylaniline, 3-methyl-
4-(2,2-dicyanovinyl)-N,N-di(iso)-propylaniline, 3-methyl-4-
(2,2-dicyanovinyl)-N,N-di(n)-butylaniline, 3-methyl-4-(2,2-dicyanovinyl)-N,N-di(iso)-butylaniline,
3-Methyl-4-(2,2-dicyanovinyl)-
N,N-di(sec)-butylaniline, 4-(2,
2-dicyanovinyl)-N-ethyl-N-(n)-propylaniline, 4-(2,2-dicyanovinyl)
-N-ethyl-N-(n)-butylaniline, 4-
(2,2-dicyanovinyl)-N-methyl-N-(n)
-propylaniline, 4-(2,2-dicyanovinyl)-N-methyl-N-(n)-butylaniline,
3-Methyl-4-(2,2-dicyanovinyl)-N
-Methyl-N-(n)-propylaniline, 3-methyl-4-(2,2-dicyanovinyl)-N-methyl-N-(n)-butylaniline, 3-methyl-4-
(2,2-dicyanovinyl)-N-ethyl-N-(n)
-propylaniline, 3-methyl-4-(2,2
-dicyanovinyl)-N-ethyl-N-(n)-butylaniline, which gives a magenta color represented by (): 4-tricyanovinyl-N,N-dimethylaniline, 4-tricyanovinyl-N , N-diethylaniline, 4-tricyanovinyl-N,N-di(n)
-Propylaniline, 4-tricyanovinyl-
N,N-di(iso)-propylaniline, 4-tricyanovinyl-N,N-di(n)-butylaniline,
4-tricyanovinyl-N,N-di(iso)-butylaniline, 4-tricyanovinyl-N,N-di(sec)-butylaniline, 3-methyl-4-tricyanovinyl-N,N- dimethylaniline, 4-
Tricyanovinyl-N-methyl-N-(n)-propylaniline, 4-tricyanovinyl-N-methyl-N-(n)-butylaniline, 4-tricyanovinyl-N-ethyl-N-(n )-propylaniline, 4
-tricyanovinyl-N-ethyl-N-(n)-butylaniline, 4-tricyanovinyl-N-ethyl-N-(iso)-butylaniline, 4-tricyanovinyl-N-ethyl-N-( sec)-butylaniline, 4-tricyanovinyl-N-(n)-propyl-
N-(n)-butylaniline, 3-methyl-4-tricyanovinyl-N-methyl-N-ethylaniline. Note that among the dyes represented by the general formula (), (), or (), two or more dyes having different substituents may be used in combination. Preferred binders include polysulfone, polyethersulfone, polycarbonate, polyphenylene oxide, and polyarylate, which have excellent solubility and heat resistance. These binders have good adhesion to film substrates and excellent heat resistance, so they do not peel off from the substrate even when heated during recording. Furthermore, sufficient recording density can be obtained due to good adhesion and dispersibility.
Furthermore, since it has good compatibility with the dyes represented by the general formulas (), (), and (), good image quality can be obtained due to uniform sublimation of the dye. In addition to being used as a binder, the above resin is also used as a viscosity modifier in ink compositions, and the amount used varies depending on the printing method, but is usually 5 to 20% by weight, particularly 7 to 20% by weight.
Used in a range of 15% by weight. The polysulfone in the above resin has good heat resistance, adhesion, and compatibility with dyes, and has a solubility in chlorinated solvents and brominated solvents of 20% by weight or more, so various viscosities can be adjusted, making it particularly effective. It is. Solvents for ink preparation include methylene chloride, chlorobenzene, chloroform, chlorinated solvents such as 1,2-dichloroethane, bromoform,
Solvents with high solubility for the dyes represented by the general formulas (), (), and () and the resins described above, such as brominated solvents such as 1,2-dibromoethane, are suitable. Furthermore, since toluene has a low solubility for dyes, it is suitable as a solvent for fine particle dispersion or as a boiling point regulator. The dye may be dissolved or dispersed in the solvent. Alternatively, it may be a mixed system of dissolved and dispersed materials. Note that it is effective to include an inorganic pigment such as silica or alumina in the coloring material layer in order to impart heat resistance to the coloring material layer and to avoid direct contact between the coloring material layer and the image receptor. The appropriate viscosity of the ink composition is in the range of 0.1 to 30 P (poise), and it can be applied to a wide range of printing methods such as gravure, flexo, offset, and screen printing, and the amount of ink deposited after drying is 0.1 to 10 g/poise.
^m2 range is suitable. The present invention will be explained in more detail below using specific examples. Examples Manufacturing, printing, and recording examples using the ink composition of the present invention will be explained. (1) Production of ink composition 120 weight of alumina particles with an average particle size of 3 μm are mixed with a 15 weight% monochlorobenzene solution of polysulfone.
The mixture was mixed to 100 parts by weight and dispersed by kneading in a three-roll mill for 5 minutes to prepare a masterbatch. To these, a dye represented by the following structural formula, a monochlorobenzene solution of polysulfone, and monochlorobenzene were added to prepare an ink composition.
However, the cyan dye was used by kneading the ink composition in a ball mill for 20 hours to atomize and disperse the dye. Yellow magenta was used in a completely dissolved system.

【table】

(2) Printing These ink compositions were printed on a 9 μm thick polyethylene terephthalate film (PET) coated on both sides with a 1 μm thick ultraviolet curable resin using a gravure printing machine as shown in FIG. Ink composition 1 was supplied from ink pan 2 to plate cylinder 3, and while scraping off excess ink composition 1 with doctor blade 4, it was printed on PET 6 on impression cylinder 5. In Figure 1, only printing with one type of ink composition is shown, but in actual printing, three of the same units as in Figure 1 are arranged in series and printed in the order of magenta, yellow, and cyan, as shown in Figure 2. A transfer body 10 was obtained in which patterns of magenta 7, yellow 8, and cyan 9 were lined up. (3) Recording Figure 3 shows an example of recording using the dye transfer material as described above. The transfer body 10 has a binder 13 on the PET 6,
It has a structure in which a coloring material layer consisting of a dye 14 and pigment particles 15 is formed, a thermal head 11 is placed on the PET 6 side, and an image receptor 12 is placed on the coloring material layer side.
were placed respectively. Images were recorded using the thermal head 11 on an image receptor 12 made of polypropylene synthetic paper coated with polyester under the following conditions. Main scanning and sub-scanning linear density: 4 dots/mm Recording power: 0.7 W/Dot head heating time: 2 to 8 msec As a result, each color has pixels corresponding to dots at each heating time, and the average recording density at 8 msec. Images with (average reflection densities of five different 5 mm diameter recording areas) of 1.6, 1.0, and 1.5 or higher were obtained for magenta, yellow, and cyan, respectively. When these images were subjected to a sunlight fastness test according to JIS0841, they were all in the 3rd to 5th grade for sunlight fastness. In addition, high viscosity ink compositions prepared by using various dyes represented by general formulas (), (), and () as sublimable dyes in addition to the examples and adjusting the amount of solvent as appropriate can also be printed by flexographic printing, offset printing, etc. and obtained good results. Effects of the Invention As described above, the present invention provides an ink composition for thermal recording and transfer materials that uses a sublimable dye that is stable and has excellent sublimation ability, and provides sufficient recording density and good image quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a gravure printing machine using the ink composition for thermal recording transfer materials of the present invention;
FIG. 2 is a plan view showing a printed pattern by gravure printing, and FIG. 3 is a sectional view showing an example of a recording state using a heat-sensitive recording transfer member. 1... Ink composition, 2... Ink pan, 3...
...Plate cylinder, 6...PET, 10...Transfer body, 13...
...Binder, 14...Dye, 15...Pigment particles.

Claims (1)

[Scope of Claims] 1 At least one type of sublimable dye represented by the following general formulas (), (), and (), and polysulfone, polyethersulfone, polycarbonate, polyphenylene oxide, and polysulfone. An ink composition for a thermal recording transfer material comprising at least one binder selected from arylates and at least one solvent selected from among chlorinated solvents, brominated solvents, toluene, cyclohexanone, and 1,4-dioxane. (In the formula, X represents a hydrogen atom or a methyl group, R and R' each represent a methyl group, an ethyl group, a linear or branched propyl group, or a butyl group). 2. The ink composition for a thermal recording transfer material according to claim 1, wherein the dye is composed of two or more sublimable dyes having different substituents among the dyes represented by the general formula (), (), or (). thing. 3. The ink composition for a thermal recording transfer material according to claim 1, wherein the sublimable dye is dissolved in a solvent. 4. The ink composition for a thermal recording transfer material according to claim 1, wherein the sublimable dye is dispersed in a solvent. 5. The ink composition for thermal recording transfer material according to claim 1, which is a mixed system in which the sublimable dye is dissolved in a solvent and dispersed in a solvent.