JPH0473575B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a novel image receiving element for thermal transfer,
More specifically, the present invention relates to an image receiving element for thermal transfer, in which an image receiving layer contains a phenolic resin, and a color image is obtained by thermal transfer. (Prior Art) When obtaining a color image by the subtractive color method, the three primary colors are yellow, magenta, and cyan. Among these, yellow is a complementary color to blue, and is required to be clear yellow and have a maximum absorption wavelength of 420 to 480 nm. Also, magenta is green
It is a complementary color, and requires a clear reddish-purple color with a maximum absorption wavelength of 520 to 580 nm. Cyan is a complementary color to red, and is a clear blue-green color with a maximum absorption wavelength of 620 to 720 nm. However, commonly existing dyes are yellow, orange, red, violet, blue, and green, and in order to obtain color images with excellent color reproduction by subtractive color method, the maximum absorption wavelength is shifted to the yellow, magenta, and cyan regions. Although many designs of dye molecule structures have been carried out, the current situation is that they require complicated steps, are difficult in terms of conditions, and have problems in terms of yield. On the other hand, as an image receiving element for thermal transfer, JP-A-57-
No. 107885 and No. 57-137191 devised a paper support coated with an aqueous dispersion of saturated polyester, and JP-A-57-198458 and No. 57-
No. 207250 proposes a heat-developable photosensitive material in which the polyester support also serves as an image-receiving layer.
However, when the dye is dyed on the saturated polyester image-receiving layer, it is observed that the dye moves to the longer wavelength side compared to when the dye is dissolved in ethyl acetate solvent, but the movement width is not enough to control the color tone. do not have. (Object of the present invention) An object of the present invention is to provide a color image with excellent color reproducibility. Another object is to provide an image-receiving element for thermal transfer that cooperates with a dye to broadly shift the maximum absorption wavelength of the dye. (Structure of the Invention) As a result of various studies in line with the purpose of the present invention, it was discovered that the maximum absorption wavelength of the dye can be significantly shifted by bringing the phenol resin and the dye into contact, mutually dispersing them, or uniformly dissolving them. Ta. The effect is remarkable, and the maximum absorption wavelength of the dye can be moved to a longer wavelength side than the maximum absorption wavelength of the dye when dyed on polyethylene terephthalate film (50% crystallinity). Based on the above findings, the object of the present invention is achieved by a technical configuration in which a target dye is thermally transferred to an image-receiving layer containing a phenolic resin. The phenolic resin according to the present invention includes phenols (phenol, catechol, ethylphenol,
t-butylphenol, cyclohexylphenol, resorcinol, cresol, xylenol, t
- Octyl cresol, resorcinol, pyrogallol, t-amyl cresol, etc.) and aldehydes (formaldehyde, acetaldehyde, acrolein, crotonaldehyde, furfural, paraformaldehyde, etc.) are condensed with acid or alkali. When condensed with acids, novolac-type resins are obtained, which are further treated with excess formaldehyde,
Further hardening can be achieved by adding formaldehyde, hexamethylenetetramine, etc.
When condensed using an alkali, resol, resitor, or resist is produced depending on the degree of condensation. Phenol resin can also be dissolved in a solvent such as alcohol or drying oil to form a varnish. Furthermore, the phenolic resin used in the present invention has 1
A phenolic resin condensed with one or more types of phenols and one or more types of aldehydes,
It may be a mixture of two or more different phenolic resins, or it may be a condensation of two or more different phenolic resins. Regarding phenolic resins, including "Phenol Resin" (Nikkan Kogyo Shimbun Co., Ltd., Plastic Materials Co., Ltd.), Japanese Patent Application Laid-Open Nos. 123035-1982 and 55-1980,
No. 105254, No. 55-105380, No. 55-153948, No.
They are described in Japanese Patent Publication No. 55-161250, Japanese Patent Publication No. 56-20543, etc., and all of these can be used in the present invention. Next, specific examples of phenolic resins that are effective in the present invention are shown below. However, l, m, and n indicate the polymerization molar ratio. (Example phenolic resin) The degree of polymerization of these phenolic resins is from 2 to
10000, preferably 3-1000. The image-receiving element of the present invention is preferably one in which a layer containing a phenolic resin is provided on a support, but the phenolic resin may be contained in the support, and the support itself may serve as an image-receiving layer. Supports used in the present invention include paper, baryta paper, synthetic paper, aluminum foil, acetyl cellulose film, cellulose ester film, polyvinyl acetal film, polyether sulfone film, polystyrene film, polycarbonate film, polyvinylidene chloride film, and polyethylene film. Examples include terephthalate film. In the present invention, the image-receiving layer containing a phenolic resin may use a binder, and examples of the binder include natural or synthetic resins, such as casein, vegetable protein, gum tragacanth, gum arabic, starch, dextrin, Gelatin, glue, alginic acid, agar, polyethylene glycol, polyethylene glycol ester, propylene glycol ester, polyacrylamide, polyacrylic acid, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble polyvinyl butyral, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carpoxy Examples include methyl cellulose, polyvinyl acetate, oil-soluble polyvinyl butyral, acetyl cellulose, polymethyl acrylate, polybutyl acrylate, polybutyl methacrylate, polystyrene, polyvinyl pyridine, polyethylene terephthalate, and epoxy resin. In addition, in the image receiving layer containing phenolic resin,
Titanium white, silica, talc, clay, barium sulfate, calcium carbonate, glass powder,
Inorganic additives such as kaolin, zinc oxide, etc. may also be added. Further, for the purpose of improving the fastness of the image, an ultraviolet absorber, an antioxidant, a quenching substance, etc. may be included. In the present invention, the method of incorporating the phenolic resin into the image-receiving element is not particularly limited, but it may be a method of coating or dipping on the support that forms the image-receiving element, or a method of adding the phenolic resin in advance when forming the support. There are ways to store it. In the former case, the phenolic resin can be applied in the form of a solution, powder, or emulsion, or by dipping or coating by a method such as latex impregnation. In the latter case, paper can be made by using a paper machine to make a slurry of natural or synthetic pulp with paper strength enhancers, sizing agents, fillers, etc., and phenolic resin, or by adding phenolic resin to a synthetic polymer dope. There are methods for forming a film.
The amount of phenol resin applied is 0.01g/m ² ~ 100
g/m ² , preferably 0.05 g/m ² to 50 g/m ² . The image-receiving element of the present invention allows for tone adjustment by shifting the maximum absorption wavelength of any dye. Examples of dyes include azo dyes, azomethine dyes, and indoaniline dyes, and the effects of azomethine dyes and indoaniline dyes are remarkable. Azomethine dyes have the following C═N- bonded chromophore in their molecules, and are generally formed from a compound having an active methylene group and an aromatic primary amine. In particular, the oxidative coupling reaction product of an open-chain active methylene compound and a p-phenylenediamine derivative results in a yellow dye, and the reaction product of a 1-phenyl-5-pyrazolone derivative results in a magenta dye. Specific examples of azomethine dyes are shown below. Indoaniline dye refers to N-(p-aminophenyl)-p-quinone imine and its derivatives, and is usually reduced by a condensation reaction of p-nitrosophenol or quinone chloroimine with dialkylaniline or in an alkaline solution. by the reaction of nitroso or nitrodialkylanilines with phenols or naphthols in the presence of agents,
Furthermore, it is synthesized by oxidative coupling reaction of a mixture of p-phenylenediamine derivative and phenol or naphthol. Specific examples of indoaniline dyes are shown below. In the present invention, thermal transfer refers to transfer of a dye by sublimation, vaporization, melting, or diffusion by a solvent due to heat. The image receiving element constructed based on the knowledge of the present inventors is suitably used as an image receiving element for thermal transfer in the present invention. That is, the ink sheet for thermal transfer and the image-receiving element of the present invention are superimposed, and the dye transferred onto the image-receiving element in response to thermal information from a thermal head or the like comes into contact with a tone adjusting agent (phenolic resin) contained in the image-receiving element. When mixed or dissolved, it exhibits a desirable color tone. The image receiving element of the present invention is disclosed in Japanese Patent Application No. 57-122596,
No. 57-205477, JP-A No. 57-186744, No. 57-
No. 179840, No. 57-198458, No. 57-207250, Patent Application No. 57-229649, No. 57-229650, No. 57-
It can be applied to heat-developable photosensitive materials or thermal diffusion transfer methods as shown in No. 229675. That is, after giving optical information, the heat-diffusible dye released by a thermal phenomenon comes into contact with, mixes with, or dissolves the tone adjusting agent contained in the image-receiving element, and exhibits a desirable tone. . (Example) Next, the present invention will be specifically described with reference to Examples. Example 1 100 μm thickness with 2 g/m ² gelatin subbing
on transparent polyethylene terephthalate film
1.46g/ ^m2 water-soluble polyvinyl butyral (degree of polymerization 650, average molecular weight 33000, degree of butyralization 9mol)
%, degree of acetylation 12 mol%, Eslec W-201,
(manufactured by Sekisui Chemical Co., Ltd.) was provided, and each layer contained 8.0×10 ⁻⁴ mol/m ² of the pigment listed in Table 1 below, which was dispersed by alumina ball mill dispersion. A transparent polyethylene terephthalate film with a thickness of 100 μm is superimposed thereon as an image-receiving layer, and a thickness with a gelatin undercoat is added.
3.7 g of the above phenolic resin No. (42) was placed on a 100 μm transparent polyethylene terephthalate film.
² m2 coatings were prepared, layered one on top of the other so that the water-soluble polyvinyl butyral layer and the phenolic resin layer were in contact with each other, and then heated at 140°C for 20 seconds using 3M's "Deiberotz Permodule 277". It was heated. The maximum absorption wavelength (λmax EA) of each azomethine dye in an ethyl acetate solution, the maximum absorption wavelength (λmax PET) when thermal transfer dyeing is applied to a polyethylene terephthalate film, and the maximum absorption wavelength (λmax PET) when thermal transfer dyeing is applied to a phenolic resin layer. λmax Ph) is shown in Table 1.

【table】

[Table] Compared to thermal transfer dyeing on polyethylene terephthalate film, thermal transfer dyeing on phenolic resin has a longer maximum absorption wavelength, and a better color tone can be obtained. Example 2 3.8 g of phenol resin No. (16) and 2.3 g of polyvinyl butyral (BL-1, Sekisui Chemical) were dissolved in a mixed solvent of 70 c.c. of methanol and 30 c.c. of acetone, and 1.2 g of barium sulfate was added. After that, wet film thickness on art paper
An image receiving paper was made by coating at 15 μm and drying. This receiving paper is white and highly flexible. Next, a xylene solution of silicone resin (KR-266, Shin-Etsu Chemical Co., Ltd.) was coated as a heat-resistant protective layer on one side of the 10 μm thick polyethylene terephthalate film, and dried, and the other side was covered with acrylic ester polymer latex. On top of the coating layer and gelatin layer, Eslec W-201 8% aqueous solution 45 c.c. Azomethine dye M-1 0.63 g, D-xylitol 2.8
A transfer paper was obtained by applying a ball mill dispersion containing 0.21 g of starch, 0.21 g of starch, and 37 c.c. of water to a wet film thickness of 33 μm. The image receiving paper and the transfer paper were combined, the power applied to the thermal head was kept constant at 0.8 W/dot, and the pulse width was changed from 5 mS (approximately 2.8 × 10 ^-3 J to 40 mS (approximately 22.4 × 10 ^-3 J)).
When the dye was applied stepwise up to 100 ml, a step wedge image of magenta dye was obtained on the image-receiving paper. In addition, the maximum spectral absorption is 555 nm, and when transferred to polyethylene terephthalate film using the same method,
A magenta image with better color tone than 527 nm was obtained. Example 3 When the same operation as in Example 2 was carried out using indoaniline dye C-21 instead of azomethine dye M-1, a cyan step wedge image with a maximum absorption wavelength of 645 nm was obtained. Example 4 In Example 3, when phenolic resin No. (6) was used instead of phenolic resin No. (16), a cyan step wedge image with a maximum absorption wavelength of 642 nm was obtained. Example 5 To 7.45 g of 4-sulfopenzotriazole silver, 24 c.c. of Eslec W-201 8% aqueous solution, 1.3 g of ossein gelatin, 110 c.c. of water, and 25 c.c. of methanol were added and dispersed in an alumina ball mill. A silver salt dispersion was obtained. To 25 c.c. of this silver salt dispersion, 0.21 g of silver phthalate, 0.16 g of phthalazine, 0.44 g of the following compound MX-1, 0.42 g of the following developing agent DeV-1, and 8% water-soluble polyvinyl alcohol 105 (manufactured by Kuraray) 5c.c., Wed 10
cc, and 36 mg of silver iodide emulsion with an average grain size of 0.04 μm was added, and the mixture was coated onto photographic baryta paper using a wire bar to a wet film thickness of 55 μm. The dried sample was exposed to 30,000 CMS through a step wedge. Japanese paper was sandwiched between the coated surface of the exposed sample and the coated surface of the image receiving paper of Example 2, and the paper was pressed and heated for 30 seconds with an iron having a surface temperature of 160°C.
The sample and receiver paper were torn off. A negative image of a magenta step wedge with a maximum reflection density of 0.97, a minimum reflection density of 0.08, and a maximum absorption wavelength of 553 nm was obtained on the surface of the receiving paper. As a result of analysis of the magenta dye formed in the image-receiving layer, it was found to be azomethine dye M-1, which is an oxidized coupling of MX-1 and DeV-1. Example 6 When the same operation was performed using CX-1 shown below instead of MX-1 in Example 5, cyan with a maximum reflection density of 0.86, a minimum reflection density of 0.08, and a maximum absorption wavelength of 670 nm was observed on the surface of the receiving paper. A step wedge image was obtained. Example 7 The same conditions as in Example 5 were carried out using a 100 μm thick transparent polyimide film (KAPTON, manufactured by DuPont) coated with acrylic acid ester polymer latex as a support instead of the photographic baryta paper in Example 5. A photosensitive layer was formed by coating. A white reflective layer and an image-receiving layer having the following compositions were provided on the upper layer, and a transparent polyethylene terephthalate film having a thickness of 50 μm was adhered onto the image-receiving layer. <White reflective layer> (g/m ² ) Titanium dioxide (average particle size 1.5 μm) 12 Eslec W-201 1.3 <Image receiving layer> (g/m ² ) Phenol resin No. (42) 2.1 Eslec BM-2 (Sekisui) Chemistry) 1.0 The photosensitive layer side of this sample was exposed to 30,000 CMS through a step wedge, and the photosensitive layer side was pressed with an iron having a surface temperature of 160°C for 30 seconds. A negative silver image was formed on the photosensitive layer, and a negative magenta image with a maximum reflection density of 1.12, a minimum reflection density of 0.05, and a maximum absorption wavelength of 554 nm was obtained on the image-receiving layer. Example 8 The same operation as in Example 5 was carried out using the following compound MX-2 in an equimolar amount in place of MX-1. The image receiving layer has a maximum reflection density of 0.95 and a minimum reflection density of 0.95.
0.07, a magenta image with a maximum absorption wavelength of 554 nm was obtained. Example 9 In Example 1, when the same operation was performed using the following azo dye YX-1, the λmax EA of the dye was 409 nm, the λmax PET was 417 nm,
λmax Ph is 434 nm, and it is clear that the phenolic resin is effective even for azo dyes. Effects of the Invention The objects of the present invention can be achieved, and images with excellent color purity and color balance can be obtained at least in thermal transfer image formation, and the difficulties of dye synthesis can be avoided.

Claims (1)

[Claims] 1 A thermal transfer image-receiving element that obtains a color image by thermally transferring one or more types of dyes selected from azo dyes, azomethine dyes, or indoaniline dyes, in which the image-receiving layer contains a phenolic resin when the dye is thermally transferred. An image-receiving element for thermal transfer, characterized in that the wavelength is longer than the maximum absorption when a polyethylene terephthalate film (50% crystallinity) is dyed with the dye.