JPH06239035A - Sublimation type thermal transfer recording system - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a sublimation-type thermal transfer recording system recording medium having excellent light resistance of a recorded image and having very little discoloration or fading due to sunlight or fluorescent light. In a recording material of a sublimation-type thermal transfer recording system in which an image receiving layer dyed with a sublimable dye transferred from a transfer sheet is formed on one surface of a substrate sheet, the image receiving layer is
(A) 40 to 100 parts by weight of the dyeable resin, (b) 60 to 0 parts by weight of the crosslinkable component, and (c) a total of the dyeable resin and the crosslinkable component of at least one specific bisphenol compound. A recording medium containing 1 to 20 parts by weight with respect to 100 parts by weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer recording type recording medium capable of forming a recorded image having excellent light resistance.

[0002]

2. Description of the Related Art The sublimation type thermal transfer recording system is characterized in that the sound at the time of recording is quiet, the apparatus is small and inexpensive, the maintenance is easy, and the output time is short. Further, since a sublimation dye is used, it is possible to easily perform recording with a high gradation by continuously changing the amount of heat generation energy, and it has characteristics such as high density and high resolution. Therefore, compared to other recording methods, it is particularly advantageous to obtain a full-color hard copy, and a color printer,
It is widely used as a recording method for video printers.

However, since an image recorded by the sublimation type thermal transfer system is formed of a sublimable dye, it generally has poor light resistance and is easily discolored or discolored by sunlight or fluorescent light. There is a drawback that.

For the purpose of solving this drawback, it is common practice to add an ultraviolet absorber or a light stabilizer to the image-receiving layer of the recording medium, which improves the light resistance to some extent, but is not sufficient. Hard to say.

Further, as described in JP-A-1-127387, a method of adding a specific phenolic antioxidant to the image receiving layer, JP-A-3-19893 and JP-A-61-229594. As described in the publication, a method of adding a specific phosphorous antioxidant to the image-receiving layer has been proposed, and a slight light resistance improving effect is recognized, but the degree of fading or discoloration by light is Still big.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to improve the above-mentioned drawbacks of the prior art and to provide a sublimation type thermal transfer recording system which is excellent in light fastness of a recorded image and has very little fading or discoloration by light. To obtain a recording medium.

[0007]

This problem is solved by incorporating a bisphenol compound having a specific structure in the image receiving layer.

That is, the present invention provides a sublimation-type thermal transfer recording type recording medium in which an image receiving layer dyed with a sublimable dye which migrates from a transfer sheet is formed on one surface of a substrate sheet, wherein the image receiving layer is (A) 40 to 100 parts by weight of the dyeable resin, (b) 60 to 0 parts by weight of the crosslinkable component, and (c) the dyeability of at least one of the bisphenol compounds represented by the following general formula (1). Resin and crosslinkable component total 100
It is 1 to 20 parts by weight with respect to parts by weight.

[0009]

[Chemical 2]

(However, in the general formula (1), R ₁ , R
₂ , R ₃ and R ₄ are H, an alkyl group having 1 to 4 carbon atoms, A is —SO ₂ —, —S—, and an atomic group having 1 to 6 carbons as a main skeleton. ) Hereinafter, the present invention will be described in detail.

Films or papers are suitable as the substrate sheet constituting the recording medium of the present invention. For example, various plastics such as polyester film, polyethylene film, polypropylene film, polystyrene film, nylon film, vinyl chloride film, etc. Films and white films obtained by adding white pigments and fillers to these; papers mainly composed of cellulose fibers such as printing paper, art paper and coated paper; synthetic mainly composed of plastic fibers such as acrylic paper, polypropylene paper and polyester paper Examples include paper.

These papers or films may be used as they are, and those that have been subjected to pretreatments such as cleaning, etching, corona discharge, irradiation with active energy rays, dyeing and printing as needed. You may. Also, a laminated base material obtained by laminating two or more of the above base materials can be used. The thickness of the base sheet is not particularly limited, but may be 20
It is preferably about 500 μm.

An image receiving layer is formed on at least one surface of the substrate sheet, and the image receiving layer is a layer that develops a color by receiving a sublimable dye transferred from the transfer sheet.

The dyeing resin contained in the image-receiving layer is not particularly limited as long as it dyes well with a sublimable dye and does not cause blocking with the transfer sheet during recording, and examples thereof include methyl cellulose, ethyl cellulose and ethyl hydroxy. Cellulose-based resins such as cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and cellulose acetate; polyvinyl-based resins such as polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinyl acetate, polyvinyl chloride, polyvinylpyrrolidone, polystyrene, and polyacrylonitrile; polymethyl (meth ) Acrylic resins such as acrylate, polybutyl (meth) acrylate, polyacrylamide, polyester resins, polycarbonate resins, polyurethane resins, polyamide resins, Fluororesin, polycaprolactone resins, polyarylate resins, polysulfone resins, and copolymers thereof, or mixtures thereof, and the like.

Of these, the polyester resin is preferably contained as at least one component of the dyeing resin because it dyes well with a sublimable dye and also has good storage stability of the obtained image.

The image-receiving layer of the present invention preferably contains a crosslinkable component for the purpose of further improving the releasability between the image-receiving layer and the transfer sheet. For example, a thermosetting component such as isocyanate and polyol may be contained and thermally crosslinked after the image-receiving layer is formed, or as disclosed in JP-A-62-46689 and JP-A-63-67188. ,
Crosslinking agent curable with active energy rays, eg (meth)
An image receiving layer can be obtained by applying a resin composition containing a monomer or an oligomer having an acryloyloxy group on a substrate and then curing the resin composition with active energy rays.

In particular, a method of blending components capable of crosslinking with active energy rays and curing with active energy rays to obtain an image receiving layer has high productivity and high gloss of the image receiving layer obtained.
In addition, the storage stability of the recorded image against heat is high, which is preferable.

The dyeing resin and the crosslinkable component are used in an amount of 40 to 100 parts by weight of the dyeing resin and 6 parts by weight of the crosslinking component based on 100 parts by weight of the total of the dyeing resin and the crosslinking component.
0 to 0 parts by weight is contained. If the amount of the dyeable resin used is less than 40 parts by weight, sufficient recording density cannot be obtained. Further, when a crosslinkable component is contained for the purpose of improving the releasability of the image receiving layer and the transfer sheet, a dyeing resin of 40 to 9 is used.
It is preferable that the amount of the crosslinking component is 5 parts by weight and the amount of the crosslinkable component is 60 to 5 parts by weight.

The resin composition containing a crosslinking agent which can be cured with active energy rays is cured with active energy rays such as electron rays and ultraviolet rays. When ultraviolet rays are used as the active energy rays, it is well known. It is desirable to include a photopolymerization initiator.

The amount of the photopolymerization initiator used is not particularly limited, but it should be contained in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the total of the above-mentioned dyeing resin and crosslinkable component forming the image receiving layer. Is preferred.

In the present invention, for the purpose of improving the light resistance of the image recorded on the image receiving layer, at least one of the bisphenol compounds represented by the general formula (1) is contained in the image receiving layer.

JP-A-1-127387 and JP-A-1-127387
By incorporating a bisphenol compound having a specific structure as described above into the image receiving layer instead of a hindered phenol antioxidant as disclosed in JP-A-171887, the light resistance of a recorded image is It was discovered that the improvement was much larger than was expected from the technology, and that light fading and discoloration were extremely reduced.

Specific examples of the bisphenol compound represented by the general formula (1) include, for example, the following structural formulas
And the like.

[0024]

[Chemical 3]

These bisphenol compounds can be used alone or in admixture of two or more.

The amount of these bisphenol compounds used is 1 to 20 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the total of the dyeing resin and the crosslinkable component forming the image receiving layer. It is desirable to let

If the amount used is too small, the excellent light resistance aimed at by the present invention cannot be obtained. On the contrary, if the amount used is too large, the bisphenol compound bleeds out to the surface of the image receiving layer, or the surface of the image receiving layer is exposed. The recording body and the transfer sheet may be fused, or the recorded image may be blurred over time.

In the present invention, for the purpose of further improving the light resistance of the image receiving layer, an ultraviolet absorber may be contained in addition to the bisphenol compound.

As the ultraviolet absorber, a known benzotriazole-based or benzophenone-based ultraviolet absorber can be used. For example, a specific example of the benzotriazole-based ultraviolet absorber is 2- (5-methyl-2-). Hydroxyphenyl) benzotriazole (manufactured by Ciba Geigy: TI
NUVIN P), 2- [2-hydroxy-3,5-bis (α, α-dimethyl-benzyl) phenyl] -2H-
Benzotriazole (Ciba Geigy: TINUVIN
234), 2- (5-t-butyl-2-hydroxyphenyl) benzotriazole (manufactured by Ciba-Geigy: TIN
UVIN PS), 2- (3,5-di-t-butyl-2)
-Hydroxyphenyl) benzotriazole (manufactured by Ciba-Geigy: TINUVIN 320), 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole (manufactured by Ciba-Geigy: TINUV)
IN 326), 2- (3,5-di-t-butyl-2-
Hydroxyphenyl) -5-chlorobenzotriazole (manufactured by Ciba-Geigy: TINUVIN 327), 2-
(3,5-di-t-amyl-2-hydroxyphenyl)
Benzotriazole (Ciba Geigy: TINUVIN
328), 2- [2-hydroxy-3- (3,4,
5,6-Tetrahydrophthalimidomethyl) -5-methylphenyl] benzotriazole (Sumitomo Chemical Industries: S
UMISORB250), 2- (4-octoxy-2-)
Hydroxyphenyl) benzotriazole and the like can be mentioned.

Specific examples of the benzophenone type ultraviolet absorber include 2,4-dihydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2,2'-
Dihydroxy-4-methoxybenzophenone, 2,2
′, 4,4′-Tetrahydroxybenzophenone, 2,
2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dioctoxybenzophenone, 2,2'-dihydroxy-4,4 '
-Didodecyloxybenzophenone, 2-hydroxy-
4-methoxy-5-sulfobenzophenone and the like can be mentioned.

These ultraviolet absorbers may be used alone or in admixture of two or more.

The amount of the ultraviolet absorber used is not particularly limited, but it is desirable to add 1 to 10 parts by weight to 100 parts by weight of the total of the dyeing resin and the crosslinkable component. If the amount used is too small, the effect of improving the light resistance is not sufficient. On the contrary, if the amount is too large, the ultraviolet absorber may bleed out to the surface of the image receiving layer or the recorded image may be blurred over time.

Further, for the purpose of further improving the light resistance of the image receiving layer, a hindered amine light stabilizer may be contained.

As the hindered amine light stabilizer, known ones can be used, and specific examples thereof include bis (2,2
2,6,6-Tetramethyl-4-piperidyl) sebacate (Sankyo SANOL LS770), bis (1,
2,2,6,6-pentamethyl-4-piperidyl) sebacate (Sankyo LS765), 1- {2
-[3- (3,5-Di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl} -4- [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyloxy] -2,2,6,6-tetramethylpiperidine (Sankyo: SANOL LS2626), 4
-Benzoyloxy-2,2,6,6-tetramethylpiperidine (Sankyo: SANOL LS744), 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [ 4, 5] Decane-2,
4-dione (manufactured by Sankyo: SANOL LS440), 2-
(3,5-di-t-butyl-4-hydroxybenzyl)
-2-n-butylmalonate bis (1,2,2,6,6-
Pentamethyl-4-piperidyl) (manufactured by Ciba Geigy: T
INUVIN 144), bis succinate (2, 2, 6,
6-Tetramethyl-4-piperidinyl) ester (manufactured by Ciba-Geigy: TINUVIN 780FF), polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine (Made by Ciba Geigy: TINUVIN 622L
D), poly {[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl- 4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]} (manufactured by Ciba-Geigy: CHIMASSORB 944LD), N, N'-
Bis (3-aminopropyl) ethylenediamine and 2,4
-Bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-
Polycondensate of 1,3,5-triazine (Ciba Geigy:
CHIMASSORB 119FL), HA-70G
(Made by Sankyo), ADEKA STAB LA-52, ADEKA STAB
LA-57, ADEKA STAB LA-62, ADEKA STAB LA-67, ADEKA STAB LA-63, ADEKA STAB LA-68, ADEKA STAB LA-82, ADEKA STAB LA-87 (all manufactured by Asahi Denka Co., Ltd.) and the like can be mentioned.

These hindered amine light stabilizers are
Although they can be used alone or in combination of two or more, in consideration of the effect of improving light resistance, it is preferable to use them in combination with the above-mentioned ultraviolet absorber.

The amount of the hindered amine light stabilizer used is not particularly limited, but it is preferably contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the total of the dyeing resin and the crosslinkable component. If the amount used is too small, the light resistance improving effect is not sufficient, and conversely if the amount is too large, the hindered amine light stabilizer may bleed out to the surface of the image receiving layer, or the recorded image may be blurred over time. .

The image-receiving layer of the present invention preferably contains a releasing agent for the purpose of improving the releasability of the image-receiving layer and the transfer sheet.

As the release agent, a silicone type surfactant,
Fluorine-based surfactants, graft polymers having a polyorganosiloxane as a trunk or a branch, compounds capable of forming a silicon-based or fluorine-containing crosslinked structure, such as a combination of amino-modified silicone and epoxy-modified silicone, and the like. The release agent can be used alone or in combination.

The amount of the release agent used is not particularly limited,
To 100 parts by weight of the total of the dyeable resin and the crosslinkable component,
It is desirable to contain 0.01 to 30 parts by weight.

Further, the above resin composition may contain an inorganic filler such as silica, calcium carbonate, titanium oxide or zinc oxide depending on the purpose of use.

In order to produce the recording medium of the present invention, the resin composition is directly coated on the surface of the substrate by a coating method such as roll coating, bar coating or blade coating,
It is possible to form an image receiving layer.

Further, in order to improve the workability of the coating operation, a solvent capable of dissolving the resin composition, for example, a solvent such as ethyl alcohol, methyl ethyl ketone, toluene, ethyl acetate, dimethylformamide, tetrahydrofuran or the like is blended and suitable. It is preferable to adjust the coating viscosity.
Thereby, spray coating, curtain coating, flow coating, dip coating and the like can be easily performed.

When blending these solvents, it is necessary to volatilize and dry the solvent after coating the resin composition.

It is desirable that the image receiving layer is formed to have a thickness of 0.5 to 100 μm, preferably 1 to 50 μm. If it is less than 0.5 μm, a high recording density cannot be obtained.

In the recording medium of the present invention, a layer such as an easy-adhesion layer, an antistatic layer, a whiteness improving layer, or a composite layer combining these functions is provided between the image receiving layer and the substrate. May be.

Further, the recording medium of the present invention may be subjected to antistatic treatment, stain prevention, lubricity imparting, writability imparting and the like on the surface opposite to the image receiving layer.

[0047]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 On one side of art paper (thickness 85 μm), a white polyester film (W900, thickness: 38 μm, manufactured by Diafoil Co., Ltd.) was used, and on the other side, white polypropylene paper (made by Oji Yuka) : Yupo FPG, thickness 6
0 μm) was laminated to obtain a base material sheet. As the adhesive, Toyo Morton AD-577-1 and CAT-52 were used.

On the white polyester film surface of the obtained base sheet, the following image receiving layer coating solution was uniformly applied by a dipping method, the solvent was volatilized, and then ultraviolet rays were irradiated by a high pressure mercury lamp to give a film thickness. An image receiving layer having a thickness of 5 to 6 μm was formed to obtain a recording medium.

Coating solution for image-receiving layer Polyester resin obtained by polycondensation of terephthalic acid / isophthalic acid / ethylene glycol / neopentyl glycol (molecular weight 15,000 to 20,000, glass transition temperature 67 ° C.) 20 parts by weight terephthalic acid / isophthalic acid / Sebacic acid / Ethylene glycol / Neopentyl glycol / 1,4-Butanediol polycondensation polyester resin (Molecular weight 18000 to 20000, glass transition temperature 47 ° C) 50 parts by weight Kayarad DPHA (Nippon Kayaku 15 parts by weight 2,2-bis (4-acryloyloxydiethoxyphenyl) propane 15 parts by weight 1-hydroxycyclohexyl phenyl ketone 3 parts by weight The compound represented by the structural formula (bisphenol) A) ‥‥‥ 3.9 parts by weight 2 Hydroxy-4-octoxybenzophenone 4.8 parts by weight Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate 4.8 parts by weight Represented by the following structural formula (2). 0.5 to 0.5 parts by weight Methyl ethyl ketone ... 500 parts by weight Toluene ... 100 parts by weight

[0051]

[Chemical 4]

The obtained recording medium is a thermal transfer sheet VW-VS100 for video printer NV-MP1 manufactured by Matsushita Electric Industrial Co., Ltd.
The cyan color of the Kyocera thermal head (950
Ω, 6 dots / mm), printing was performed under the conditions of a recording voltage of 13 V and a pulse width of 10 msec. Then, the recorded image was exposed for 72 hours using a xenon long life fade meter (FAL-25AX manufactured by Suga Test Instruments Co., Ltd.), and the color difference (ΔE) before and after the exposure was measured. The results are shown in Table 1.

Example 2 A recording medium was obtained in the same manner as in Example 1 except that the compound was used in an amount of 9.1 parts by weight. ΔE of the obtained recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

Example 3 A recording medium was obtained in the same manner as in Example 1 except that the amount of the compound used was 12.1 parts by weight. The obtained recording medium is the same as that in Example 1.
ΔE was measured in the same manner as in. The results are shown in Table 1.

Comparative Example 1 A recording medium was obtained in the same manner as in Example 1 except that the compound was not used. The obtained recording medium was subjected to ΔE in the same manner as in Example 1.
Was measured. The results are shown in Table 1.

[Comparative Example 2] Example 2 except that 3.2 parts by weight of a phenolic antioxidant represented by the following structural formula (Yoshitomi Pharmaceutical: Yoshinox 2246G) represented by the following structural formula was used in place of the compound. A recording medium was obtained in the same manner as in 1. ΔE of the obtained recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

[0057]

[Chemical 5]

Comparative Example 3 An example except that 3.5 parts by weight of a phenolic antioxidant represented by the following structural formula (Yoshitomu Pharmaceutical: Yoshinox 425) represented by the following structural formula was used in place of the compound in Example 1 A recording medium was obtained in the same manner as in 1. ΔE of the obtained recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

[0059]

[Chemical 6]

[Comparative Example 4] Example 4 except that 3.5 parts by weight of a phenolic antioxidant represented by the following structural formula (Yoshitomi Pharmaceutical Co., Ltd .: Yoshinox SR) was used instead of the compound in Example 1. A recording medium was obtained in the same manner as in 1. ΔE of the obtained recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

[0061]

[Chemical 7]

[Comparative Example 5] An example of Example 1 except that 3.9 parts by weight of a phenolic antioxidant (Yoshinox BB, manufactured by Yoshitomi Pharmaceutical Co., Ltd.) represented by the following structural formula was used in place of the compound. A recording medium was obtained in the same manner as in 1. ΔE of the obtained recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

[0063]

[Chemical 8]

[0064]

[Table 1]

As is clear from Table 1, the color differences (ΔE) of the recording materials of Examples 1 to 3 are significantly smaller than those of Comparative Examples 1 to 5.

[0066]

As described in detail above, according to the present invention,
By incorporating a bisphenol-based compound having a specific structure in the image-receiving layer, a sublimation-type thermal transfer recording system recording medium having excellent light resistance can be obtained. The image recorded on the recording medium has very little fading or discoloration due to light, and greatly contributes to the popularization of video printers and the like.

Front page continuation (72) Inventor Kazuhiko Sukufu 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory

Claims (1)

[Claims] 1. A sublimation-type thermal transfer recording type recording medium having an image receiving layer dyed with a sublimable dye transferred from a transfer sheet on one surface of a substrate sheet, wherein the image receiving layer is 40 to 100 parts by weight of the adhesive resin, 60 to 0 parts by weight of the (b) crosslinkable component, and (c) at least one of the bisphenol compounds represented by the following general formula (1) as the dyeable resin and the crosslinking property. A recording medium containing 1 to 20 parts by weight based on 100 parts by weight of the total components. [Chemical 1] (However, in the general formula (1), R ₁ , R ₂ , R ₃ , R
₄ is H, an alkyl group having 1 to 4 carbon atoms, A is -SO _2- ,
-S- is an atomic group having a main skeleton of 1 to 6 carbons. )