JPS6317079A - Thermal transfer medium - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer medium having a receiving sheet having excellent surface whiteness and imparting a transfer image excellent in contrast and fastness, by forming the receiving sheet wherein a layer comprising a fine powdery substance having a particle size of 0.5-20 mum is provided to the surface of a support and a metal vapor deposition layer is provided thereon. CONSTITUTION:A thermal transfer medium consists of a receiving sheet wherein a layer comprising a fine powdery sustance having a particle size of 0.5-20 mum is provided to the surface of a support and a transfer sheet wherein a trans fer layer containing pigment and/or a dye is provided on a support. As the above mentioned fine powdery substance, white pigment, org. and inorg. salts, various clys, silica and a glass powder etc. are designated and, when the particle size thereof is 0.5-20 mum, further preferably the particle size thereof is 0.5-20 mum and the adhesion amount thereof is 0.5-10 kg/m<2>, a metal vopor deposition surface shows visually the most desireable whiteness. When the particle size is below 0.5 mum, a smooth surface is formed to impart metallic gloss and, when the particle size exceeds 20 mum, satin metallic gloss having sandy feeling caused by the coarseness of particles is shown and the image sharpness is lowered.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a heat-sensitive transfer medium that utilizes a color-forming reaction between a leuco dye and a color developer. The present invention relates to a thermal transfer medium that provides transferred images with excellent contrast and fastness.

[Prior art]

Conventionally, thermal transfer media include those consisting of a transfer sheet in which a heat-sublimable dye is provided on a support and a receiving sheet that receives the heat-sublimable dye image by thermal printing from the back side of the sheet, and media made of materials such as paraffin and wax. A combination of a transfer sheet and a receiving sheet is known, in which a transfer layer of a heat-fusible substance and a pigment or dye is provided on a support, and the former uses a heat-sublimable dye, so The dye image has poor storage stability, and an overcoat must be applied on the transferred image, and in the latter case, the mechanical strength of the paraffin used as a thermofusible substance is weak, so the transferred image is prone to friction such as rubbing. This has the disadvantage that the image deteriorates.

On the other hand, there is also known a thermal transfer medium in which substances that react with each other to form a color due to heat are supported on separate supports, and these support layers are brought into mutually facing contact to perform thermal printing.
Among these types of materials, those with high heat sensitivity tend to change color from black to red when exposed to light for a long period of time, and those with excellent light resistance have the disadvantage of low heat sensitivity.

Furthermore, a receiving sheet in which a metal vapor-deposited layer of aluminum or the like is provided on the surface of the support has been proposed, but this sheet exhibits metallic luster and thus does not have sufficient whiteness.

Furthermore, the contrast of the transferred image was low and the flexibility was poor.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive transfer medium that provides a transfer image with excellent whiteness on the surface of a receiving sheet and with excellent contrast and fastness.

〔composition〕

According to the present invention, as a first invention, a receiving sheet is provided with a fine powder substance layer having a particle size of 0.5 to 20 μm on the surface of a support, and a metal vapor deposited layer is provided thereon, and a pigment and/or pigment is provided on the support. or a transfer layer containing a dye is provided.A second aspect of the present invention provides a heat-sensitive transfer medium comprising: a transfer layer containing a dye; a receiving sheet having a metal vapor deposited layer thereon, and further having a receiving layer on the metal vapor deposited layer containing a color developer for leuco dye as a main component; and a transfer sheet containing a leuco dye as a main component on a support. A thermal transfer medium is provided, comprising a transfer sheet provided with layers.

In the thermal transfer medium of the present invention, a receiving sheet is stacked on a transfer sheet so that its receiving layer is in contact with the transfer layer of the transfer sheet, and the desired transfer is usually applied to the surface of the receiving sheet by thermal printing from the back side of the transfer sheet. In the present invention, an image is formed on a support as a receiving sheet with a particle size of 0.
Since a structure in which a metal vapor deposition layer or a receptor layer containing a color developer for leuco dye as a main component is further provided on the metal vapor deposition layer through a fine powder material layer of 5 to 20 μm, the receptor sheet can be used as a receptor sheet. The whiteness of the surface is improved, and a transferred image with excellent contrast and fastness can be obtained.

In general, methods for roughening the metal deposition surface include a method using a mechanical method such as polishing or sandblasting of the surface of the support to be deposited, and a method of attaching a fine white powder substance to the surface of the support. However, the former method requires special equipment and is difficult to provide sufficiently fine irregularities.

In the latter method, the present inventors have found that particle sizes of 0.5 to 20
It was discovered that the whiteness of the receiving sheet can be significantly improved when a micropowder of μI is used, and a transferred image with excellent contrast and fastness can be obtained, and this led to the completion of the present invention. It is something that

The fine powder substances used in the present invention include white pigments, organic and inorganic salts, various clays, silica, glass powders, etc. Specifically, zinc oxide, titanium oxide, lithopone,
Examples include white lead, magnesium carbonate, and calcium carbonate.

In the present invention, the particle size of the fine powder material is 0.5 to 20μ
m, more preferably the particle size of the fine powder material is in the range 0
．． In the range of 5 to 20 μm and the adhesion amount is 0.5 to 10 g/
When n(, the metal-deposited surface has the visually most desirable whiteness (
JIS z8741-1962 (7) 75 degree specular gloss measurement method (3% or less) with a 0 particle size of 0
．． If the particle size is less than 5 μm, the surface will be smooth, giving it a metallic luster; if the particle size exceeds 20 μm, it will exhibit a rough satin-like metallic luster due to the coarseness of the particles, and the clarity of the image will deteriorate. decrease. Note that if the particle size of the fine powder is outside the range of 0.5 to 20 microns, the desired whiteness cannot be obtained even if the amount of other materials, especially the amount of resin as a binder, is adjusted. If the binder resin is too large, it will cover the fine powder and form a smooth surface, and if it is too small, the fine powder cannot be firmly fixed to the support.

In the present invention, conventional resin binders are used, such as polyvinyl alcohol, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, starch, gelatin, polystyrene, vinyl chloride-vinyl acetate. Water-soluble, organic solvent-soluble or aqueous emulsion-forming materials such as copolymers, polybutyl methacrylate, etc. can be used.

To make the receiving sheet of the present invention, a solution containing fine powder is applied or impregnated onto a support such as paper or plastic film, and
A metal such as aluminum, zinc, tin, or antimony may be deposited thereon by a conventional vapor deposition method.

As described above, the transfer sheet used in the present invention is one in which a transfer layer containing a dye and/or pigment as a main component or a transfer layer containing a leuco dye as a main component is provided on a support. As dyes and/or pigments, various types of dyes that have been conventionally used.

Inorganic pigments or organic pigments can be used, but carbon black is particularly preferred in terms of color tone and weather resistance.

Furthermore, as the leuco dye, any of those conventionally used for pressure-sensitive paper and thermal paper can be applied, including triphenylmethane-based and fluoran-based.

Phenothiazine-based, auramine-based, and spiropyran-based substances are preferably applied. Specific examples of these leuco dyes are shown below.

3.3-Bis(P-diethylaminophenyl)-phthalide.

3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(p-dimethylaminophenyl)-6-diethylaminophenyl, 3.3-bis (p-dimethylaminophenyl)-6-chlorophthalide, 3.3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlorofluoran.

3-dimethylamino-5,7-dimethylfluorane, 3
-diethylamino-7-chlorofluorane.

3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(N-ph ly-N-ethylamino) -6-Methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'-trifluoromethylphenyl)
amino)-6-ethylaminofluorane.

2-(3,6-bis(diethylamino)-9-(o-
chloranilino)xantylbenzoic acid lactam), 3-
Diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran, 3-N-methyl -N-amylamino-6-methyl-7-
Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane.

3-(N,N-diethylamino)-5-methyl-7-(
N.

N-dibenzylamino)fluorane.

Benzoylleucomethylene blue, 6'-chloro-81-methoxy-benziindolino-pyrylosubiran, 6'-bromo-3'-methoxy-benziindolino-pyrylosubiran, 3-(2'-hydroxy-4'-dimethylaminophenyl) -3-(2'-methoxy-5'-chlorophenyl) phthalide, 3-(2'-hydroxy-47-dimethylaminophenyl)-3-(2'-methoxy-5'-nitrophenyl) phthalide, 3 -(2'-hydroxy-4'-diethylaminophenyl)-3-(2'-methoxy-51-methylphenyl)phthalide, 3-(2'-methoxy-4'-dimethylaminophenyl)-3-(2'-Hydroxy-4'-chloro-5'-
methylphenyl) phthalide, etc.

As described above, the receiving sheet of the second invention is provided with a color developer for the leuco dye as a main component on a support such as paper, synthetic paper, or plastic film through a fine powder material layer and a metal vapor deposition layer. A receptive layer is provided. In this case, as the color developer, an electron-accepting substance 1 such as a phenolic substance, an organic acid or a salt or ester thereof, etc. is used,
From the viewpoint of practicality, it is preferable to use a color developer having a melting point of 200° C. or less. Specific examples of color developers preferably applied in the present invention are shown below, and the numbers in parentheses indicate the melting point.

4-tert-butylphenol (98), 4-hydroxydiphenyl ether (84), l-naphthol (
9g).

2-naphthol (121), methyl-4-hydroxybenzoate (131), 4-hydroxyacetophenone (109), 2,2'-dihydroxydiphenyl ether (79), 4-phenylphenol (166),
4-tert-octylcatechol (109), 2
, 2'-dihydroxydiphenyl (103), 4,4
' -methylenebisphenol (160), 2.2'
-methylenebis(4-chlorophenol) (164)
, 2,2'-methylenebis(4-methyl-6-tar
t-butylphenol) (125), 4,4'-isopropylidene diphenol (156), 4,4'-isopropylidene bis(2-chlorophenol) (90)
, 4゜4'-isopropylidene bis(2,6-dibromophenol) (172), 4,4'-isopropylidene bis(2-tert-butylphenol) (110
), 4.4'-isopropylidene bis(2-methylphenol) (136), 4.4'-isopropylidene bis(2,6-dimethylphenol) (16 g), 4
．． 4'-5ec-butylidene diphenol (119)
, 4,4'-5ee-butylidene bis(2-methylphenol) (142), 4,4'-cyclohexylidene diphenol (180), 4,4'-cyclohexylidene bis(2-methylphenol) (184) , salicylic acid (163), salicylic acid methalyl ester (7
4), salicylic acid phenacyl ester (110), 4-
Hydroxybenzoic acid methyl ester (131), 4-hydroxybenzoic acid ethyl ester (116), 4-hydroxybenzoic acid propyl ester (98), 4-hydroxybenzoic acid isopropyl ester (86), 4-hydroxybenzoic acid butyl ester ( 71), 4-hydroxybenzoic acid isoamyl ester (5o), 4-hydroxybenzoic acid phenyl ester (17g), 4-hydroxybenzoic acid benzyl ester (111), 4-hydroxybenzoic acid cyclohexyl ester (119), 5-
Hydroxysalicylic acid (200), 5-chlorsalicylic acid (172), 3-chlorsalicylic acid (178), thiosalicylic acid (164), 2-chloro-5-nitrobenzoic acid (165), 4-methoxyphenol (53), 2
-Hydroxybenzyl alcohol (87), 2,5-dimethylphenol (75), benzoic acid (122), orthotoluic acid (107), metatoluic acid (111)
, paratoluic acid (181), orthochlorobenzoic acid (
142), metaoxybenzoic acid (200), 2,4-
Dihydroxyacetophenone (97), resorcinol monobenzoate (135), 4-hydroxybenzophenone (133), 2,4-dihydroxybenzophenone (144), 2-naphthoic acid (18)
4), 1-hydroxy-2-naphthoic acid (
195), 3,4-dihydroxybenzoic acid ethyl ester (128), 3,4-dihydroxybenzoic acid phenyl ester (189), 4-hydroxypropiophenone (150), salicyl salicylate (148).

Phthalic acid monobenzyl ester (107), 1,1-bis(4'-hydroxyphenyl)ethane (126),
1.1-bis(4'-hydroxyphenyl)propane (130), ■, 1-bis(4'-hydroxyphenyl)hexane (111), 1.1-bis(4'-
hydroxyphenyl)hebutane (120), 1,1-bis(4'-hydroxyphenyl)-2-propylpentane (12g), 1,1-bis(4'-hydroxyphenyl)-2-ethylhexane (87) , 2.2-bis(
4'-Hydroxyphenyl)hebutane (101), 3
, 3-bis(4'-hydroxyphenyl)hexane (
155), 1,1-bis(3'-methyl-4'-hydroxyphenyl)ethane (101), 1,1-bis(3
'-Methyl-4'-hydroxyphenyl)propane (9
4), 1,1-bis(3'-methyl-41-hydroxyphenyl)butane (135), 1,1-bis(3'
-methyl-4'-hydroxyphenyl)pentane (9
7), 1,1-bis(3'-methyl-4'hydroxyphenyl)hexane (78), 1,1-bis(3'
-methyl-4'-hydroxyphenyl)hebutane (85
), 2-(3'-methyl-4'-hydroxyphenyl)-2-(4'-hydroxyphenyl)propane (
120), 2.2-bis(3-methyl-4'-hydroxyphenyl)pentane (128), 2.2-bis(5
-methyl-4'-hydroxyphenyl)hexane (10
4), 2,2-bis(3'-methyl-4'-hydroxyphenyl)4-methylpentane (129), l.

1-bis(3'-methyl-4'-hydroxyphenyl)4-methylbutane (124), 3.3-bis(3'
-methyl-4'-hydroxyphenyl)hexane (9
0), 5.5-bis(3'-methyl-4'-hydroxyphenyl)nonane (128), 2-(4'-hydroxyphenyl)-2-(3'-chloro-4'-hydroxyphenyl)propane (101), 2,2-bis(3'-isopropyl-4'-hydroxyphenyl)propane (97), 2,2-bis(3'-tert-butyl-4'-hydroxyphenyl)propane (117)
, 2,2-bis(3'-chloro-4'-hydroxyphenyl)propane (84), 2-(4'-hydroxy-3',5'-dimethylphenyl)-2-(4'-
hydroxyphenyl)propane (127), bis(3'
-Methyl-5'-ethyl-4'-hydroxyphenyl)methane (105), 1.1-(3'-methyl-5
'-Butyl-4'-hydroxyphenyl)butane (10
4), 2.2-bis(4-hydroxyphenyl)octane (83), bis(4-hydroxyphenylmercapto)methane (55), bis(4-hydroxyphenylmercapto)methane (55), 1.2-bis (4-hydroxyphenylmercapto)ethane (173), 1.3
-Bis(4-hydroxyphenylmercapto)propane (82), 1.4-bis(4-hydroxyphenylmercapto)butane (182), 1.5-bis(4-hydroxyphenylmercapto)pentane (98), 1, 6
-bis(4-hydroxyphenylmercapto)hexane (166), ■, 3-bis(4-hydroxyphenylmercapto)acetone (74), 1,5-bis(4-hydroxyphenylmercapto)-3-oxapentane (9
3), 1,7-bis(4-hydroxyphenylmercapto)-3,5-dioxahebutane (108), 1,8-
Bis(4-hydroxyphenylmercapto)-3,6-
Thioxaoctane (100), 4-benzylmercaptophenol, 4-P-florbenzylmercaptophenol, 4-P-methylbenzylmercaptophenol, etc.

Further, in the present invention, a thermofusible substance having a melting point of 200° C. or less, preferably 150° C. or less can be added to the transfer layer and/or the receptor layer. Specific examples of thermofusible substances preferably used in the present invention include lauric acid amide, caproic acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, N-methylstearic acid amide, N-cyclohexyl Amides such as stearic acid amide, N-stearylbenzamide, N-stearylacetamide, etc., 4
-Hydroxybenzoic acid phenyl ester, 4-hydroxybenzoic acid-2-methoxyphenyl ester, salicylic acid-2-methoxyphenyl ester, benzoic acid-4-benzylphenyl ester, benzoic acid-4-methoxyphenyl ester, 4-benzoyloxybenzoic acid Examples include acid methyl ester, 4-benzoyloxybenzoic acid phenyl ester, and various waxes, but are not limited to these, of course.

When providing a transfer layer and a receiving layer on each support, conventional binders are used, such as polyvinyl alcohol, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, and polyacrylic acid. ,
Water-soluble, organic solvent-soluble or aqueous emulsion-forming materials such as starch, gelatin, polystyrene, vinyl chloride-vinyl acetate copolymer, polybutyl methacrylate, etc. can be used, but especially in the case of the transfer layer,
Resin 1 having a melting point or softening point of 50 to 130° C. For example, polyethylene, polypropylene, polystyrene, petroleum resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, vinylidene chloride resin, polyvinyl alcohol, cellulose resin, polyamide, polyacetal, polycarbonate , polyester, fluororesin, silicone resin, natural rubber, chlorinated rubber, butadiene rubber, olefin rubber, phenol resin, urea resin, melamine resin, epoxy resin, polyimide, etc. are preferably used as the binder.

In the thermal transfer medium of the present invention, each layer forming liquid is prepared by dispersing and dissolving the above-mentioned layer forming components together with a solvent such as water using a pulverizing and mixing means such as a ball mill or attritor, and this is coated on each support and dried. You can get it by doing

To perform transfer using the thermal transfer medium of the present invention, for example, when using a transfer sheet having a transfer layer (image-like transfer layer) containing dye and/or pigment as a main component, the surface of this transfer layer is Transfer can be carried out by stacking receiving sheets so that their receiving layers are in contact and passing them between heated rolls; When a sheet is used, the receiving layer of the receiving sheet is superposed on the surface of the transfer layer of the transfer sheet, and thermal printing can be performed directly from the back surface of the transfer sheet using a thermal printer.

〔effect〕

The present invention consists of the above-mentioned structure, and as a receiving sheet, a metal vapor deposited layer is provided on the support via a fine powder material layer with a particle size of 0.5 to 20 μm, or a color developer for leuco dye is further applied on the metal vapor deposited layer. By using a structure with a receiving layer as the main component, the whiteness of the surface of the receiving sheet is improved, the contrast and sharpness of the image are improved, and a transferred image with excellent fastness is obtained. be able to.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. Note that both "1 part" and "1%" shown below are based on weight.

[Preparation of transfer sheet (A-1)] Carnauba wax (mp, 82°C) 4 parts microcrystalline wax (mp, 65°C) 6 parts ethylene-vinyl acetate copolymer 3 parts carbon on a 6 μm thick polyester film black
10 parts toluene
A composition consisting of 77 parts was dispersed for 24 hours using a ball mill, and then coated and dried using a wire bar to create a transfer sheet (A-1) having a transfer layer with a coating weight of 2.5 g/rrr.

[Creation of transfer sheet (A-2)] 3-N-methyl-N-cyclohexylamine-6-methyl-7-anilinofluorane 17 parts polyvinyl chloride (s, p value) 9.7. Softening point 85°C) 2 parts methyl ethyl ketone
A composition consisting of 100 parts was applied to a transfer sheet (
Transfer sheet (
A-2) was created.

[Creation of receiving sheet (B-1)] Magnesium carbonate powder was classified according to particle size as shown in Table 1 below, and each classified particle was dispersed in a styrene-butadiene emulsion (solid content 50%) solution. Adjusted.

This was applied to 45g/rd of high-quality paper, and after drying, a layer of fine powder material was provided so that the adhesion amount was 3.5g/rd.
A receiving sheet support was obtained.

Next, aluminum is deposited on the surface of the fine powder material layer,
A 0.02 micron thick vapor deposited layer was provided to obtain a roughened white receiving sheet (B-1).

[Creation of receptor sheet (B-2)] Polyvinyl alcohol 2 parts water
78
After dispersing for 24 hours using a ball mill, this composition was coated and dried on the roughened metal vapor deposited surface of the receiving sheet (B-1) using a wire bar to give a coating weight of 5 g. A receptor sheet having a receptor layer of / rrr (
B-2) was created.

Combine the transfer sheet and receiving sheet created as described above as shown in Table 1, overlap the transfer sheet and receiving sheet, and use a thermal head from the back side of the transfer sheet for 1 mJ.
When heating energy was applied to the barcode, a clear black barcode image was obtained.

Claims (2)

[Claims] (1) A fine powder material layer with a particle size of 0.5 to 20 μm is provided on the surface of the support, and a receiving sheet with a metal vapor deposited layer thereon and a transfer layer containing pigment and/or dye are provided on the support. A heat-sensitive transfer medium comprising a transfer sheet. (2) A fine powder substance layer with a particle size of 0.5 to 20 μm is provided on the surface of the support, and a metal vapor-deposited layer is provided on the surface of the support, and a receptor whose main component is a color developer for leuco dye is further provided on the metal vapor-deposit layer. 1. A heat-sensitive transfer medium comprising a receiving sheet having a layer and a transfer sheet having a transfer layer containing a leuco dye as a main component on a support.