JPH05155144A - Infrared heating type thermal transfer recording sheet - Google Patents

Abstract

PURPOSE:To obtain the title sheet having excellent transfer sensitivity and capable of giving a recorded article having high picture quality by using a specific squarylium compound as an infrared absorbing substance in the sheet having a layer containing thermal migratory dyestuffs and the infrared absorbing substance on a base film and using infrared rays for thermal transfer recording as a heating means. CONSTITUTION:In a sheet having a layer containing thermal migratory dyestuffs and an infrared absorbing substance on a base film and using infrared rays for thermal transfer recording as a heating means, a squarylium group compound shown in formula I (A represents an azulenyl group, which may also have a substituting group, or formula II, R<1> and R<2> represent a hydrogen atom, an alkyl group, which may also have the substituting group, an allyl group, an aralkyl group and an aryl group, R<1> and R<2> may be coupled mutually and also form a nitrogenated ring, R<3> represents COR<5> and SO2R<6>, R<5> and R<6> represent the alkyl group, which may also have the substituting group, an alkoxy group, a vinyl group, etc., and R<4> represents H and the alkoxy group, which may also have the substituting group) is employed as the infrared absorbing substance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive transfer recording sheet used for heat-sensitive transfer recording, particularly dye transfer type heat-sensitive transfer recording.

[0002]

2. Description of the Related Art A dye-transfer type heat-sensitive transfer recording is a heat-sensitive transfer sheet in which a heat-sensitive transfer sheet having a coloring material layer containing a heat transferable dye on a base film and an image-receiving sheet having a dye-receiving layer on the surface are superposed. Is a recording method in which the dye in the heat-sensitive transfer sheet is transferred to the image-receiving sheet by heating to record. This recording method is applied to full-color image recording such as a video printer because the transfer amount of the dye can be controlled by the amount of heating energy and gradation can be expressed.

Conventionally, as a heating means for a transfer sheet, a line type thermal head in which a heating resistor element which generates heat in response to an electric signal is formed in a line on a substrate is used.
However, it is difficult to uniformly form a large number of heating resistor elements on the substrate, which makes it difficult to manufacture a large thermal head, and it is difficult to record an image on a large screen. In addition, since there is a limit to the formation density of the heating resistor elements, there is a problem in image recording that requires high resolution.

In order to solve the problems of these thermal heads, it has been proposed to use laser light as a heating means. As the laser light, a semiconductor laser that is small and obtains high energy is particularly advantageous. Currently, there are semiconductor lasers having a transmission wavelength of 650 to 850 nm in the red to near infrared region, but those in the near infrared region of 750 to 850 nm are mainly used. In order to heat the transfer sheet by using these semiconductor lasers as a heating means, it is necessary to include a photothermal conversion substance that absorbs laser light and converts the absorbed light into heat energy in the transfer sheet. The photothermal conversion substance used here is very important because it directly affects the recording sensitivity of the transfer sheet and also affects the quality of the recorded image. The photothermal conversion substance is required to have the following characteristics.

Good absorption efficiency of laser light Good conversion efficiency of absorbed light into heat Good solubility or dispersibility in solvent or water, good stability of coating liquid, film Easy to coat ・ Stable when the transfer sheet is stored, and does not adversely affect the dyes used together ・ No heat transfer, or very small compared to dyes As the conversion substance, for example, JP-A-63-
319191, JP-A-58-16888, JP-A-2-2
074 and many others have been proposed. However, these products do not always satisfy all the above-mentioned characteristics, and more excellent products are demanded.

[0006]

DISCLOSURE OF THE INVENTION The present invention uses an infrared absorbent having a specific structure as a photothermal conversion substance having excellent characteristics in thermal transfer recording using infrared rays such as an infrared semiconductor laser as a heating means. In other words, it is an object of the present invention to provide a heat-sensitive transfer recording sheet having good transfer sensitivity and capable of providing a high quality recorded matter.

[0007]

The heat-sensitive transfer recording sheet of the present invention has a layer containing a heat transferable dye and an infrared absorbing substance on a base film, and the infrared absorbing substance is represented by the following general formula (I).

[0008]

[Chemical 3]

(In the formula, A is an azulenyl group which may have a substituent or the following formula:

[0010]

[Chemical 4]

Represents R ¹ and R ² represent a hydrogen atom, an alkyl group which may have a substituent, an allyl group, an aralkyl group or an aryl group, and R ¹ and R ² are linked to each other to form a nitrogen-containing ring. Is also good. R ³ is -COR ⁵ or-
Represents SO ₂ R ⁶ , where R ⁵ and R ⁶ are optionally substituted alkyl group, alkoxy group, vinyl group, cycloalkyl group, cycloalkyloxy group, allyl group, aralkyl group, aryl group or aryl Represents an oxy group.
R ⁴ represents a hydrogen atom or an alkoxy group which may have a substituent. ) Is a squarylium compound.

The contents of the present invention will be described in detail below. First, the infrared absorbent represented by the general formula (I) will be described. As the substituent of the azulenyl group A of the general formula (I), an alkyl group which may have a substituent (for example, an alkyl group having 1 to 25 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms). Or an alkoxy group which may have a substituent (for example, an alkoxy group having 1 to 25 carbon atoms, preferably an alkoxy group having 1 to 8 carbon atoms, which has a substituent such as an alkoxy group or an alkoxyalkoxy group) Or an aralkyl group which may have a substituent (for example, an alkyl group having 1 to 8 carbon atoms, an alkoxy group or a benzyl group which may be substituted with a halogen atom, a phenethyl group, a phenylpropyl group). ) Or an aryl group which may have a substituent (for example, a phenyl group which may be substituted with the same substituent as the aralkyl group) or a chlorine atom, a bromine atom or the like. Androgenic atom and the like.

The azulenium ring of the azulenyl group is condensed with a benzene ring, a cyclohexene ring, a cyclopentene ring, a dihydrothiophene ring, a tetrahydropyridine ring, a furan ring, a dihydrofuran ring, a pyrrole ring, a dihydropyrrole ring, a thiazole ring and the like. May be. Specific examples of the squarylium compound represented by the general formula (I) include those shown in Table 1 and Table 2, and these are known substances and are disclosed in JP-A-60-228.
448, 62-138459 and the like.

Since these compounds have an absorption band having a large absorption intensity in the wavelength band of 700 to 900 nm, it is known that the absorption efficiency of infrared laser light is good and the heat conversion efficiency of absorbed light is also good. It was By the way, when the inventors of the present invention adopted these compounds as an infrared absorbing agent for the recording sheet, the coating liquid was easy to prepare due to their large solubility in the solvent used for the thermal transfer recording sheet, and especially for dyes. There is no adverse effect, the storage stability of the coating liquid and transfer sheet is good, and the thermal transfer property is very small compared to dyes, and it is transferred to the image receiving paper itself even in high-speed recording where high thermal energy is applied. The present invention has been completed by finding out that the image quality does not deteriorate and the recording image quality does not deteriorate.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

[Table 4]

[0019]

[Table 5]

[0020]

[Table 6]

[0021]

[Table 7]

[0022]

[Table 8]

[0023]

[Table 9]

[0024]

[Table 10]

[0025]

[Table 11]

[0026]

[Table 12]

[0027]

[Table 13]

[0028]

[Table 14]

Next, the transfer sheet of the present invention will be described. In the transfer sheet of the present invention, the layer containing the infrared absorbing substance may be formed at any position of the base film, but it is formed on the same side as the color material layer containing the heat transferable dye. It is advantageous, and it is more advantageous to use it by mixing it with a dye in the color material layer.

In the case of forming a coloring material layer containing an infrared absorbing material in the coloring material layer, an ink is prepared by dissolving the infrared absorbing material together with a dye and a binder in a medium or dispersing it in the form of fine particles. Apply ink to the base film,
It can be carried out by drying. As the binder for preparing the ink, cellulose-based, acrylic acid-based,
Starch-based and epoxy-based water-soluble resins and acrylic resins, methacrylic resins, polystyrene, polycarbonate, polysulfones, polyether sulfones, polyvinyl butyral, ethyl cellulose, acetyl cellulose,
Examples thereof include resins soluble in organic solvents such as polyester, AS resin, and phenoxy resin.

As a medium for the ink preparation, in addition to water, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, and aromas such as toluene, xylene and chlorobenzene. Group, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, methylene chloride,
Chlorine solvents such as chloroform and trichlorethylene,
Ethers such as tetrahydrofuran and dioxane,
Examples thereof include organic solvents such as N, N-dimethylformamide and N-methylpyrrolidone.

The heat transferable dye may be any one as long as it can be transferred to the receiving layer by the action of heat. Azo dyes and anthraquinone dyes which have been proposed for conventional heat transfer sheets for thermal heads. Dyes, azomethine dyes, methine dyes, indoaniline dyes, quinophthalone dyes and the like can be used. Infrared absorber,
The amount of the dye and the binder used is 1 to 200% by weight, preferably 10 to 10% by weight of the infrared absorber with respect to the dye.
0% by weight, and 10 to 500% by weight, preferably 50 to 200% by weight, of the pigment is suitable for the binder.

In the above ink, in addition to the above components, if necessary, organic or inorganic non-sublimable fine particles, dispersant, antistatic agent, defoaming agent, antioxidant, viscosity adjusting agent, release agent Etc. can be added. The thickness of the color material layer is 0.1 to 10 μm
Is suitable, and preferably 0.5 to 5 μm.

As the base film of the transfer sheet, a film of transparent plastic having good heat resistance such as polyester, polycarbonate, polyamide, polyimide, polyaramid is suitable, and the thickness thereof is in the range of 3 to 200 μm. I can name it. Of the above base films, the polyethylene terephthalate film is particularly advantageous in consideration of mechanical strength, solvent resistance, economy and the like.

In the transfer sheet of the present invention, a dye-permeable protective layer may be further formed on the color material layer, if necessary. As a method for applying the ink to the base film, a gravure coater, a reverse roll coater, a rod coater, an air doctor coater or the like can be used.

[0036]

The present invention will be described in detail with reference to the following examples, but the examples do not limit the present invention. Example 1

[Table 15] a) Ink preparation Infrared absorber No. 1 compound 2 g Dye 1,1,2-tricyano-2- (P-ethylbutylaminophenyl) ethylene 8 g Cellulose acetate 10 g (Product name: L-30; product of Daicel Chemical Co., Ltd.) Methyl ethyl ketone 80 g ─────── ──────────────────────────── Total 100 g A mixture of the above composition was treated with a paint conditioner for 10 minutes to prepare an ink.

B) Preparation of Transfer Sheet The above ink was applied onto a polyethylene terephthalate film (6 μm thick) using a wire bar and dried (dry film thickness of about 1 μm) to obtain a transfer sheet.

C) Preparation of image receptor 10 parts of vinyl chloride / vinyl chloride resin (product name: VYHD; Union Carbide product), amino-modified silicone (product name: KF-3)
93; Shin-Etsu Chemical Co., Ltd. product) 0.5 part, 15 parts methyl ethyl ketone, 15 parts xylene synthetic paper (product name: YUPO FPG150: Oji Yuka Co., Ltd. product)
Apply with a wire bar and dry (dry film thickness about 5 μm),
Further, it was produced by treating in an oven at 80 ° C. for 30 minutes.

D) Transfer recording The transfer sheet is superposed so that the ink-coated surface is in contact with the receiving layer surface of the image receptor, and is wound around a drum having a diameter of 250 mm so that the image receptor is in contact with the drum (vacuum is sucked from the inside of the drum. Furthermore, a transparent cover film of polyethylene terephthalate having a thickness of 25 μm was attached on the transfer sheet so that the transfer sheet and the image receiver closely adhered to each other.) While rotating the drum, the transmission wavelength of 830
Transfer recording was performed under the following conditions while continuously irradiating a semiconductor laser beam of nm. Equipment used: Matsushita Electric Industrial Co., Ltd., model number LN9810
0PR Drum rotation speed: 500 rpm Laser light output: 80 mW Laser light spot diameter: 4 μm Recording line density: 100 lines / mm By transfer recording under the above conditions, a uniform and clear magenta-colored recording material was obtained. The color density of the recorded matter was measured with a densitometer TR-927 manufactured by Macbeth Co., Ltd., and the result was 0.7.
It was 5.

Example 2 In preparation of the ink, instead of the dye of Example 1, dye 1,
Ink preparation, transfer sheet preparation, image receptor preparation and transfer recording were carried out in the same manner as in Example 1 except that 8 g of 1-dicyano-2- (P-diethylamino-O-methylphenyl) ethylene was used. A uniform and vivid yellow recording material having a density of 0.80 was obtained.

Example 3 Instead of the dye of Example 1 in the preparation of the ink, the dye O-
Acetamide-N- (P-diethylamino-O-methylphenyl) P-quinoneimine [acetamide is in the ortho position with respect to the carbon atom bonded to the oxygen atom of quinone]
Ink preparation, transfer sheet preparation, image receptor preparation and transfer recording were carried out in the same manner as in Example 1 except that 8 g was used to obtain a uniform and clear cyan recording material having a color density of 0.70. ..

Example 4 In addition to the components of Example 1 in the preparation of the ink, 0.2 g of true spherical silicone resin particles (average diameter 2 μm) was further added to prepare an ink, a transfer sheet was prepared, and an image receptor was prepared. And transfer recording were performed in the same manner as in Example 1, and the color density was 0.70.
A uniform and vivid magenta-colored recorded matter was obtained.

Example 5 A transfer sheet was prepared by further coating an aqueous solution of polyvinyl alcohol on the color material layer of the transfer sheet prepared in Example 1 to form a protective layer of about 0.1 μm. Using this transfer sheet, transfer recording was carried out in the same manner as in Example 1 to obtain a uniform and vivid magenta color recorded product having a color density of 0.65.

Example 6 In place of the infrared absorber of Example 1 in the preparation of the ink,
Ink was prepared, a transfer sheet was prepared, an image receptor was prepared and transfer recording was carried out in the same manner as in Example 1 except that 2 g of the infrared absorbent shown in Table 3 was used. I got a record.

Comparative Example Instead of the infrared absorber of Example 1 in the preparation of the ink,
Ink preparation, transfer sheet preparation, image receptor preparation and transfer recording were carried out in the same manner as in Example 1 except that 2 g of the infrared absorbent shown in Table 3 was used, and the results shown in Table 3 were obtained.

[0046]

Table 16 Table 3 Example or Comparative Example No. Infrared absorbent recording density Example 6-1 Table 2 No. Compound of No. 2 0.72 Example 6-2 No. 2 in Table 2 Compound of No. 4 0.75 Example 6-3 No. Compound No. 17 0.73 Example 6-4 No. 17 in Table 1 Compound of 2 0.70 Comparative Example 1 ────── <0.05 Comparative Example 2 Phthalocyanine Pb complex 0.35 (Compound described in JP-A-63-319191 Example 1) Comparative Example 3 Ni compound ^* 0 .38 (Compound described in Example 3 of JP-A-63-319191) * Ni compound has the following structure

[0047]

[Chemical 5]

[0048]

When the heat-sensitive transfer sheet of the present invention is used, an infrared laser can be used as a heating means to obtain a clear recorded matter having a high density.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Urano Sanboshi Kasei Co., Ltd. Research Institute, 1000 Kamoda-cho, Midori-ku, Yokohama-shi, Kanagawa

Claims (1)

[Claims] 1. A sheet having a layer containing a heat transferable dye and an infrared absorbing substance on a base film, which is used for thermal transfer recording using infrared rays as a heating means, wherein the infrared absorbing substance has the following general formula (I): ) [Chemical 1] (In the formula, A is an azulenyl group which may have a substituent or the following formula: Represents. R ¹ and R ² represent a hydrogen atom, an alkyl group which may have a substituent, an allyl group, an aralkyl group or an aryl group, and R ¹ and R ² are linked to each other to form a nitrogen-containing ring. Is also good. R ³ represents —COR ⁵ or —SO ₂ R ⁶ , and R ⁵ and R ⁶ are an alkyl group which may have a substituent, an alkoxy group, a vinyl group, a cycloalkyl group,
It represents a cycloalkyloxy group, an allyl group, an aralkyl group, an aryl group or an aryloxy group. R ⁴ represents a hydrogen atom or an alkoxy group which may have a substituent. ) A sheet for infrared heat-sensitive thermal transfer recording, which is a squarylium compound represented by