JP2751440B2 - Image receptor for thermal transfer recording - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image receiving body for thermal transfer recording.

[Conventional technology]

A transfer recording sheet having a color material layer mainly composed of a heat-diffusible dye and a binder resin on one side of a base film is heated by a heating means such as a thermal head, and the dye is mainly dyed with a resin capable of dyeing. In a dye transfer type thermal transfer recording in which an image receiving layer as a component is transferred onto an image receiving body having a surface of a substrate and recording is performed, the image receiving body is required to have the following performance.

During transfer recording, it is easy to peel off from the transfer recording sheet after recording without fusing with the transfer recording sheet, and recording with good gradation can be obtained.

The dyeing property of the dye in the image receiving layer is good, high density recording is possible, and the dye is hardly transferred after recording.

Good storage stability such as light resistance and dark fading of the recorded material.

For the above-described performance of the transfer recording image receiving body, it is important to select a resin used for forming the image receiving layer. Various resins have been proposed so far, but there are still insufficient ones.

[Problems to be solved by the invention]

The present invention has good dyeability in the image receiving layer, enables high-density recording, hardly causes migration of the dye after recording, and has good storage stability such as light resistance and dark fading of the recorded matter. It is an object of the present invention to provide a dye transfer type thermal transfer recording image receiver.

[Means for solving the problem]

That is, the present invention relates to a dye transfer type thermal transfer recording image receiving body having an image receiving layer containing a dye-dyeing resin as a main component on the surface of a substrate, wherein the following general formula (I) (In the formula, R ¹ and R ² are different from each other and represent an alkyl group optionally having a hydrogen atom substituent, a phenyl group optionally having a substituent, and an alkenyl group. K, l, m, n represents the percentage of each structural unit in the formula, and 50 <k + 1 <85, k
(It is in the range of {0 1} 0, 10 <m <50, 0 <n <30). An image receiving body characterized by having an image receiving layer mainly composed of a polyvinyl acetal resin represented by the following formula:

The polyvinyl acetal resin used in the present invention can be obtained by acetalizing polyvinyl alcohol with two different aldehydes or acetals by a known method. In the above general formula (I)
R ¹ and R ^{2 each} represent a hydrogen atom; a C ₁ -C ₁₅ linear or branched alkyl group; substitution of a chloromethyl group, a bromomethyl group, an aminomethyl group, a 7-carboxyheptyl group, a benzyl group, etc. Alkyl group; phenyl group; substituted phenyl group having an alkyl group, an alkoxy group, an amino group, a carboxyl group, a hydroxy group, a halogen atom or the like on a benzene ring; those having an alkenyl group such as a 2-methylvinyl group or a vinyl group. It is, but especially hydrogen, an alkyl group of C ₁ -C _8, a benzyl group, a phenyl group, a tolyl group, those having such chlorophenyl group. The general formula (I) and similar structural formulas described in the present specification are simply formulas for expressing the quantitative ratio of each component of the resin, and specify the arrangement (for example, block structure or the like). is not. The polyvinyl acetal-based resin represented by the general formula (I) may contain a small amount of other components as long as the object of the present invention is not lost. The degree of acetalization is preferably in the range of 50 to 85 mol%, and the degree of polymerization of the starting polyvinyl alcohol is suitably 300 to 3,000. The polyvinyl alcohol may partially contain unsaponified acetyl groups, but the amount is desirably 30 mol% or less.

The ratio between R ¹ and R ² may be arbitrary, but a range of 3: 7 to 7: 3 is appropriate.

The above-mentioned resins may be used alone or in a mixture in the image receiving layer of the image receiving body of the present invention. The image-receiving layer of the present invention contains the above resin as a main component, but may optionally contain a saturated polyester resin, an acrylic resin, a methacrylic resin, a styrene resin, a polycarbonate resin, a cellulose acetate, a polyvinyl butyral, a vinyl chloride resin, and a vinyl chloride. , Vinyl acetate copolymer resin, polyarylate resin,
AS resin may be included.

The image receiving layer preferably contains a release agent to prevent heat fusion between the color sheet and the image receiving body during transfer recording and to improve the releasability of both after transfer. Particularly preferably, a silicone compound is used, but other various waxes, fluorine compounds, fine particles and the like are also effectively used. Also, in order to obtain peelability,
A layer containing these release agents may be formed on the image receiving layer.

The image receiving layer or the layer containing a release agent formed on the image receiving layer contains an ultraviolet absorber, a light stabilizer, an antioxidant, an optical brightener, an antistatic agent, and the like. Is also good.

Examples of the base of the image receiving body include various papers formed from cellulose fibers, various synthetic papers synthesized from synthetic resins, and plastic films.

As a method for forming the image receiving layer of the present invention, the polyvinyl acetal resin is dissolved in an appropriate solvent, an appropriate release agent is added, and if necessary, other resins and the various additives are added, What is necessary is just to prepare a coating liquid, apply it on a substrate, and dry it.

As the solvent for preparing the coating solution, various organic solvents having good solubility in the polyvinyl acetal resin used in the present invention can be used, but methanol, ethanol, propanol, alcohol solvents such as butanol, Cellosolve solvents such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; aromatic solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ester solvents such as ethyl acetate and butyl acetate; Methylene, trichloroethylene,
Halogen solvents such as chlorobenzene, ether solvents such as tetrahydrofuran and dioxane, and amide solvents such as dimethylformamide and N-methylpyrrolidone are used.

The coating method can be arbitrarily selected from commonly used methods, for example, a method using a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, etc. Bookstores published in 1977) are used. The thickness of the image receiving layer formed on the substrate is usually 0.1 to 2 as a dry coating film.
0 μm, preferably 1 to 10 μm.

The sublimable dye used in the color sheet for thermal transfer recording used together with the image receptor of the present invention includes azo, anthraquinone, nitro, styryl, naphthoquinone, quinophthalone, azomethine, coumarin, Various nonionic sublimable dyes such as a condensed polycyclic system are used.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the examples do not limit the present invention.

Example 1 (a) Preparation of Image Receiver A polyvinyl acetal resin (10 parts by weight) was dissolved in methyl ethyl ketone (15 parts by weight) and toluene (15 parts by weight), and amino-modified silicone “KF393” (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the solution in an amount of 0.5 part by weight. The coating solution for the image receiving layer was applied to a synthetic paper made of polypropylene having a thickness of 150 μm with a wire bar and dried to form an image receiving layer having a dry film thickness of about 5 μm, thereby producing an image receiving body.

The above-mentioned polyvinyl acetal resin was obtained by acetalizing polyvinyl alcohol (degree of saponification: 99 mol%, degree of polymerization: 2,400) with acetaldehyde and butyraldehyde.

(B) Preparation of Color Sheet A biaxially oriented polyethylene terephthalate film (6 μm thick) having a heat-resistant lubricated back surface on an ink-coated surface, 5 parts by weight of a magenta-based sublimable dye represented by the following structural formula (A), polycarbonate resin An ink consisting of 10 parts by weight and 85 parts by weight of toluene was applied and dried to form a color material layer having a dry film thickness of about 1 μm, thereby producing a color sheet.

(C) Transfer Recording Test and Storage Stability Test of Recorded Material (i) Transfer Recording Test The ink-coated surface of the above color sheet is superimposed on the image receiving layer surface of the image receiving body prepared in (a) above, and a heating resistance of 8 dots / mm. Using a thin-film type line thermal head having a body density, recording was performed under the following conditions to obtain a recorded matter having a color density shown in Table 1 below.

Recording line density 8 lines / mm Applied power of thermal head 0.3 W / dot Applied pulse width of thermal head 6 ms (ii) Storage stability test of recorded matter The above recorded matter was exposed with a xenon fade meter for 20 hours and exposed. The degree of subsequent discoloration was measured with a color difference meter, and the results are shown in Table 1 below.

Table 1 shows the results of observing the above recorded matter under a condition of 60 ° C. × 60% RH for 5 days and then observing the degree of color bleeding of the recorded matter with a microscope.

Examples 2 to 9 In place of the polyvinyl acetal resin used in Example 1, an image receiver was prepared using the polyvinyl acetal resin shown in Table 1, and the image receiver and the color sheet were prepared in the same manner as in Example 1. It was prepared and tested, and the results are shown in Table 1.

The polyvinyl acetal resin of each example was obtained by acetalizing polyvinyl alcohol with two corresponding aldehydes.

Comparative Examples 1 and 2 An image receiving member and a color sheet were prepared in the same manner as in Example 1 except that an image receiving member was prepared using the polyvinyl acetal resin shown in Table 1 instead of the polyvinyl acetal resin used in Example 1. It was prepared and tested, and the results are shown in Table 1.

The polyvinyl acetal resin used here was obtained by acetalizing polyvinyl alcohol with a corresponding aldehyde.

Comparative Example 3 Polyvinyl chloride (degree of polymerization 1,100, Wako Pure Chemical Industries, Ltd.)
Was dissolved in 100 parts by weight of tetrahydrofuran, and the amino-modified silicone "KF393" was added to the solution in an amount of 0.5 parts by weight.
A coating solution prepared by adding parts by weight was applied to a synthetic paper made of polypropylene with a thickness of 150 μm using a wire bar and dried to form an image receiving layer having a dry film thickness of about 5 μm, thereby producing an image receiving layer body. Each color sheet was prepared in the same manner as in Example 1, and a test was performed using the above-mentioned image receptor in the same manner as in Example 1, and the results shown in Table 1 below were obtained.

Comparative Example 4 A method was performed in the same manner as in Example 1 except that an image receiving body was prepared using a polyester resin (trade name: Byron 200: manufactured by Toyobo Co., Ltd.) instead of the polyvinyl acetal resin used in Example 1. Create a receiver and a color sheet,
The test was performed and the results are shown in Table 1.

[Effect of the Invention] The image receiving body for thermal transfer recording of the present invention is easy to manufacture, and when the image receiving body of the present invention is used as the image receiving body for sublimation type thermal transfer recording, high density recording can be performed and light fastness can be obtained. It is possible to obtain a recorded matter having good storage stability such as fixing property and fixing property.

Therefore, it can be advantageously used for color recording in an OA terminal such as a facsimile, a printer, a copying machine, etc., which is rapidly spreading in recent years, and for color recording of a television image.

Claims (1)

(57) [Claims] 1. A compound represented by the following general formula (I) (In the formula, R ¹ and R ² are different from each other and represent a hydrogen atom, an alkyl group optionally having a substituent, a phenyl group optionally having a substituent, or an alkenyl group. K, l, m , n represents the percentage of each structural unit in the formula, 50 <k + 1 <85,
(K ≠ 0 1 ≠ 0, 10 <m <50, 0 <n <30) An image-receiving layer mainly composed of a polyvinyl acetal resin represented by the following formula: Recording receiver.