JPS60236791A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To provide the titled medium for use on a thermal printer or the like, capable of producing excellent transferred coloring matter images even on an ordinary paper having low surface smoothness, wherein a heat-expandable substance containing layer is intermediately provided between a base and a heat- fusible coloring material layer. CONSTITUTION:Between (A) the base and (B) the heat-fusible coloring material layer (e.g., a combination of a scale wax and a slack wax in a ratio of 1:9-9:1) is provided (C) the heat-expandable substance containing layer comprising (i) 100pts.wt. of a resin and (ii) for example, 0.1-90pts.wt., preferably, 1.0-60pts.wt. of a heat-expandable substance (e.g., ammonium carbonate) to obtain the desired recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer recording medium. Specifically, the present invention relates to a thermal transfer recording medium that provides a good dye transfer image even on plain paper with low surface smoothness.

Conventional technology] Thermal transfer recording media have traditionally been used to produce recording sheets such as plain paper using thermal printers, thermal facsimiles, etc.
- It is used as a recording strip to transfer and form an image on. This thermal transfer recording medium has at least one coloring material layer 41 on a support, and the coloring material layer includes:
For example, a layer containing a coloring agent such as a pigment and a heat-melting substance is known. In addition, as a support,
In order to obtain good reproducibility of the dye transfer image obtained from the color material layer coated on this L, a film of the type 1, etc., which is excellent in surface smoothness and J-method stability, is used.

When these conventional thermal transfer recording media print on various types of paper ranging from paper with low smoothness to paper with high smoothness, it is possible to print well on paper with high smoothness, or print on paper with low smoothness. If this is done, "fading" will occur in the line drawings, and in the case of so-called solid black, "white spots" will appear, making it very difficult to see. This is a major obstacle to the widespread use of thermal printers, and a solution is urgently needed.

On the other hand, thermal transfer recording media in which a resin layer is interposed between the support and the coloring material layer are also known from Japanese Patent Laid-Open No. 57-36698. It is mainly intended for multiple printing of 2 or more times, and when printed on plain paper with low smoothness, ``fading'' or ``white spots'' occur, as in the case of ``-''.

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and it is possible to perform good printing in a wide range of smoothness from paper with high smoothness to paper with low smoothness. The technical challenge is to

[Means for Solving the Problems] - The thermal transfer recording medium of the present invention for solving the technical problem described above is a thermal transfer recording medium in which a heat-melting coloring material layer is laminated on a support. A layer containing a thermally expandable substance is interposed between the body and the heat-melting coloring material layer! It is characterized by the fact that

The present invention will be explained in more detail below.

The thermally expandable substance-containing layer in the thermal transfer recording medium of the present invention contains a thermally expandable substance and a resin as main components.

The thermally expandable material used in the present invention is heated during recording1; it expands and acts to press the colorant components of the coloring material layer onto the transfer paper.1For example, the foamable material used. The foamable material may be any material that foams due to thermal energy when printing is performed using the thermal transfer recording medium of the present invention and can contact the coloring material layer components with the transfer paper. A compound that foams at 60 to 200°C is preferable. Compounds with such foaming properties include common foaming agents that have foaming properties at 60 to 200°C, such as ammonium carbonate, sodium bicarbonate,
Inorganic blowing agents such as nitrourea; dinitrosopentamethylenetetramine, N,N'-dimethyl-N,N! -Nitros foaming agents such as citrosoterephthalamide; Hensensulfonylhydrazide', P-toluenesulfonylhydrazide, p,p'-oxybis(benzenesulfonylhydrazide), 3.3'cissulfonyl hydrazide , toluene disulfonyl hydrazide, p-
Toluenesulfonylhydrazone, p, p'-Thiohis (pensenesulfonylhydrazide), ←Toluenesulfonylhydrazone, P-Toluenesulfonylazide, p
-) Sulfohydrazide blowing agents such as luenesulfonyl semicalhecyto; azo blowing agents such as azobisin butyronitrile, azodicalphonamide, barium anancarphonate, diethylazocarboxylate; naphthoquinone diazide derivatives, etc. Can be used in or in combination.

In addition, when using a foaming agent with high photosensitivity such as a naphthoquinonediazide derivative, it is preferable that a light-shielding substance such as carbon black or an ultraviolet absorber be added as an additive to the thermally expandable substance-containing layer.

The thermally expandable material of the present invention is the resin 1 of the thermally expandable material-containing layer.
0.1 to 90 parts by weight, preferably 1
．． It is preferable to add 0 to 60 parts by weight, more preferably 5.0 to 50 parts by weight.

The resin used in the thermal transfer recording medium of the present invention to be kneaded with the thermally expandable substance to form the thermally expandable substance-containing layer is as follows:
Any resin may be used as long as it has adhesion to the support and the coloring material layer, but polyvinyl butyral resin, ethylene-ethyl acrylate resin, ethylene-vinyl acetate resin, epoxy resin, etc. generally give good results.

The thermally expandable material of the present invention may be incorporated into the thermally expandable material-containing layer using any method, such as dispersing it in a resin or dissolving it in a suitable solvent and adding it into the thermally expandable material-containing layer. It can be added as an agent.

The present invention will be explained in more detail below.

The heat-fusible coloring material layer in the present invention may be any layer that can be partially or completely transferred to the transfer paper by heat, and includes a heat-fusible substance (a low melting point substance or a low softening point substance), a colorant, a soft The main ingredient is

The heat-melting substance used in the present invention has a melting point (measured by Hatsuhyo MPJ-2 model (a)) or a softening point (measured by the ring and beads method) of 40-120"C1, preferably 60-120"C1.
It is a solid or semi-solid substance of I 20 'c, and specific examples include carnauba wax, wood wax, auriculia wax, vegetable wax such as espalt wax, beeswax, insect wax, shellac wax, spermaceti wax, etc. In addition to petroleum waxes such as animal waxes, paraffin waxes, microcrystalline waxes, ester waxes, and oxidized waxes, and mineral waxes such as montan wax, otsugarite, and ceresin; palmitic acid, stearic acid, marcaric acid, henochu, etc. High-quality fat and alcohol; palmityl alcohol,
Higher alcohols such as stearyl alcohol, behenyl alcohol, marcanyl alcohol, myricyl alcohol, and eicosanol; higher fatty butylene esters such as cetyl palmitate, myricyl valmitate, cetyl stearate, and myricyl stearin; acetamide, propionic acid amide, and palmitic acid; Amides such as amide, stearic acid amide, and amido-wax; rosin derivatives such as estercam, rosin maleic rvrs fat, rosin phenol resin, and hydrogenated rosin; phenolic resin, terpene resin, cyclopentadiene resin, aromatic resin, etc. High molecular compounds; higher amines such as stearylamine, behenylamine, palmitinamine; polyethylene glycol 4000
, polyethylene oxide such as polyethylene glycol eooo, etc., and these may be used alone or in combination of two or more. Among these, higher amides such as palmitin amide, stearic acid amide, oleic acid amide, and amide wax are preferred. In addition, ``a thermofusible solid component that is solid at room temperature'' described in JP-A-54-68253 and JP-A-55
-1055791=; The "vehicle" described in the publication may be used.

The low melting point substance used in the color material layer of the present invention is particularly preferably a hard wax and a soft wax (one of each!! or two or more types). Hard wax [25° (! (10
Examples of waxes with a penetrating degree (according to JIS K 2530) of less than 8 include: ■ Ester waxes (natural ester waxes such as carnauba wax and montan wax, and Hoechst manufactured by Hoechst);
Wax E, F, KP, KPS, BJ, OP, O
M, X22. U and O5 synthetic ester wax, etc.)
, >>M wax (wax obtained by oxidizing wax such as paraffin wax and microcrystalline wax, manufactured by Hiki Seiho Co., Ltd. (7) NFS-9210, N
PS-6115, Toyo Heto 0 Light Company i9 PETR
0NABAIC, CARDIS 314, etc.), ・■Low molecular weight polyethylene wax (especially molecular weight 300-10
00, POLYWAX manufactured by Sokusho Petrolite Co., Ltd.
500 o and 655 etc.), t'Dchu 7-ten') Su (Hoechst Wax S and LP manufactured by Hoechst)
etc.) etc.). Also, soft wax [2
Penetration degree at 5°C (100g) (JIS K 25
According to 30. Examples of waxes with an IZ value of 8 or more include microcrystalline wax (Nisseki Microwax 155°180 (manufactured by Hon Sekiyu Co., Ltd.), HI-M
l(Knee 1080.Hl-141G-2085゜Old-Old G-2095.HI-MIC Knee 1070.Old-Old G-
1045, HI-MIC-2045 (manufactured by Hiki Seirosha)
, 5TARWAX 100. BE 5QUARE17
5.185. vIcroRv, uLTRAFtEx(
(manufactured by Toyo Petrolite Co., Ltd.), stearic acid, behen ugliness, stearyl alcohol, white wax, beeswax, stearin dodecyl, stearon, sorbitan monophtearate, polyoxyethylene monostearate, or Diakarna 30 and Tirekarna pA3oL (manufactured by Mitsubishi Kasei Corporation)
etc. can be mentioned. In addition, when such hard wax and soft wax are used in combination, the weight ratio used is 1:8 to 9:1 (more preferably 2:8 to 1:1).
8:2) is fine.

The colorant to be contained in the color material layer of the present invention may be appropriately selected from dyes and pigments, and examples of the dye include direct dyes, durable dyes, basic dyes, disperse dyes, and oil-soluble dyes (
(including oil-soluble metal complex dyes). These dyes may also be pallast dyes.

On the other hand, as the pigment, in addition to 11 pigments such as phthalocyanine pigments, inorganic pigments such as carbon black can be used.

The coloring agent to be contained in the coloring material layer of the present invention is particularly preferably non-sublimable, and as a non-sublimating colorant, it can be transferred to a recording sheet such as plain paper together with a heat-fusible substance during heating recording. Any non-sublimable substance that can be used and has a color may be used. Non-sublimable colorants preferably used in the present invention are colorants excluding sublimable (including those that vaporize with melting or dissolution) used in mordant dyes and the like.

Basic dyes preferably used as the coloring agent of the present invention include, for example, crystal violet cc, I, 4255
5), malachiteg') -n (C, 1,42000)
, Methyl Violet (C:, 1.42535), Victoria Blue (G, 144045), Mazienta (
Triphenylmethane dyes such as C, 1,42510), diphenylmethane dyes such as Auramine CG, 1.855), Testorafuroxin FF (C;, 14807)
0), Eisenkathylon Yellow 3GLH (Hodogaya Chemical Co., Ltd. product, C, 1,48055), Aisenkyiron Red 6B'H (C, 1,48020), Astrazone Colden Yellow GL (Bayer Inc. product, G,
Methine and azamethine dyes such as 1°48054), Rhodamine B (G, 1.4500), Rhodamine 1
Xanthine dyes such as 3G (C, 1°45160),
Thiazole azo and triazole azo dyes such as Astrazon Blue-GL (C, 1, 11052), Astrazon Red F3BL (C, 1, 11055), Eisenryoku Chiron Blue-50H (c, L11085), methylene blue (C, Quinoneimine dyes such as [52015), Eisen Chiron Red GTL) 1 (C, 1, 1'+
085), Cevron Yellow 3RL, (DuPont product, C, 1, 11087), Astrazone Blue FGL
Examples include insulating azo dyes and anthraquinone dyes having an onium group at the structural end, such as (c, 1.61512).

The oil-soluble metal complex dyes are, for example, symmetric l:2 type azo metal complex dyes, asymmetric l:2 type azo metal complex dyes, 1
: I-type azo metal complex dyes, azomethine metal complex dyes, formazan metal complex dyes, metal phthalocyanine dyes, and organic base salts of these dyes. Specifically, Aisenspiron Blue-3RH (Hodogaya Chemical Co. product, C, I, Solvent Yellow 25),
f Hon Fast Yellow R (BASF product, G,
1.18890), Isenspiron Red 2RH (G
, 1. Solvent Orange 40), Pomelo Fast Scarlet B ((1:, 1.12783), Eisenspiron Red GEH (G, 1. Solventlet 84),
Zapon Fast Red BE (C, 1, 12715),
Zapon Fast Violet BE (C, 1, 12L9B
), Cyanine Blue BB (Sumitomo Chemical Co., Ltd. product, C, 1
，? 416Q), Helifast Black 113804 (
Orient Chemical Co., Ltd., C, 1, 12195), Eisenspirone Yellow 3RH Special (C, 1, Solvent Yellow 2.5:1), Eisensviron Orange 2RH Special (C, R, Solvent Orange 4)
0:1), Isenspiron blue 2BNH (C, I
, Solvent Blue 11? ), Zapon Fast Blue HFL (C:, 1.74350), Izesispiron Blank BH Special ('G, 1. Solvent Bra.
22:1), etc.

Acidic dyes include, for example, C,1, acid, and yellow 19
, C, (, 7 Gid Red 37, G, I, 7 Sid Blue 62, C, 1, Acid Orange 10, c,
+, acid blue 83, C, 1, acid black 0
1st prize is mentioned.

Direct dyes are C,1, Direct Yellow 44, C,I
.

Direct Yellow +42, C, 1, Direct Yellow 12, C, 1, Direct Blue 15, G, 1. Direct Blue 25, C, 1, Direct Blue 249
,G,1. Direct Red 81. c, ■, Direct 8, C, L tie left tread 31, C, 1,
Typical examples include 154, C, 1, and direct bra tsuk 1f.

The disperse dyes are G, I Disbo's Yellow 5, C1, Disbo's Yellow 51. G.1. Dispose Yellow 64, C, 1, Dispose Red 43, C, I Dispose Red 54, C, 1, Dispose Red.

+35, C', I, Disbo's Blue 56. C
, 1, Disbo's Bluef 3, C,1, Disbo's 91, and the like.

The palasted dyes used in the invention are dyes having at least one pallast group in the dye matrix, such as azo dyes, azomethine dyes, anthraquinone dyes, naphthoquinone dyes, sterine dyes, quinophthalo dyes, and phthalocyanine dyes. . Palast group is a group that is highly soluble in heat-fusible substances, such as alkyl group, cycloalkyl group, aralkyl group, alkoxy group, alkylsulfonylamino group, alkylsulfonyl group, hydroxylalkyl group, cyanoalkyl group, alkoxycarbonylalkyl group, alkoxy It is a group having an alkyl group having 6 or more carbon atoms, such as an alkyl group or an alkylthio group, or an alkylene group. Particularly preferred is a palast group having at least one alkyl group having carbon a6 or more in the molecule. As an example of the structure of the palasted dye preferably used in the present invention, there is
Examples include, but are not limited to, those described in Patent Application (A) filed April 25, 2015 ().

The softener used in the present invention is a low softening point resin selected from ethylene-ethyl acrylate resin, ethylene-vinyl acetate resin, etc., preferably one with a softening point (measured by the RA ball method) of 40 to 80°C. Can be mentioned.

Although the composition ratio of the coloring material layer of the present invention is not limited, the amount of the heat-melting substance is 50 to 85 parts (more preferably 70 to 85 parts) per 100 parts (parts by weight, same hereinafter) of the total solid content of the coloring material layer. 85 parts), 5 to 20 parts of the colorant, and 0 to 30 parts (more preferably 1 to 10 parts) of the softener.

The coloring material layer of the present invention may contain various additives in addition to the above-mentioned components. For example, vegetable oils such as castor oil, linseed oil, olive oil, animal oils such as whale oil, and mineral oils may be suitably used.

Note that the support used in the thermal transfer recording medium of the present invention is preferably a support that has heat-resistant strength, high dimensional stability, and high surface smoothness. Materials include, for example, papers such as plain paper, condenser paper, laminated paper, coated paper, resin films such as polyethylene, polyethylene terephthalate, polystyrene, polypropylene, polyimide, paper-resin film composites, aluminum foil, etc. Metal sheets and the like are preferably used. The thickness of the support is usually about 60 lm or less, especially 2
Preferably it is ~20 lm. Furthermore, in the thermal transfer recording medium of the present invention, the structure on the back side of the support may be optional, and a backing layer such as an anti-sticking layer may be provided.

In the thermal transfer recording medium of the present invention, a technique suitable for coating a layer containing a thermally expandable substance on a support such as a polymer film and a layer of a thermally meltable coloring material applied on the layer containing a thermally expandable substance are used. A technique suitable for
No. 3, No. 55-105579, etc., and are known in the art, and these techniques can also be used in the present invention. For example, the thermally expandable material-containing layer (and the thermally meltable colorant layer) can be formed by hot-melt coating with the composition, or by solvent coating with a coating solution obtained by dissolving or dispersing the composition in an appropriate melt. This layer was formed by The thermally expandable material-containing layer of the present invention (
As a coating method for the heat-melting coloring material layer), any known technique can be employed, such as a reverse roll coater method, an extrusion coater method, a gravure coater method, and a wire bar coater method. The heat-melting coloring material layer of the present invention may have a thickness of 20 gm or less, more preferably 1 to 15 gm. Further, the thermally expandable substance-containing layer of the present invention preferably has a thickness of 5 JLm or less, more preferably 0.1 to 3p, rn or less.

The thermal transfer recording medium of the present invention may contain highly thermally conductive fine powder in its constituent layers or in its support. The highly thermally conductive fine powder has a higher thermal conductivity than the above-mentioned resin (
For example, thermal conductivity 6.0×1o-' -25,0XlO
-' cal/sec * cm * °C) and has a high melting point, and many metals such as aluminum and copper are possible, as well as oxides such as tin oxide, aluminum oxide, magnesium oxide, titanium nitride, etc. Nitrides of can also be used. The particle size of the highly thermally conductive fine powder is preferably 3 μm or less, more preferably 0.01” Igm. For example, when it is included in the thermally expandable material-containing layer, the mixing ratio of the resin and the fine powder as described above is The volume fraction of fine powder is 10~
80% is desirable, more preferably 20-60%.

It is preferable that the highly thermally conductive fine powder is dispersed in the thermally expandable material-containing layer, or in addition, the support and/or the color A'! It may be contained in the layer.

The heat-sensitive transfer recording medium of the present invention has other constituent layers such as an undercoat layer (for example, a layer with a film) and a ten-coat layer (for example, a layer made of a heat-melting substance). Good too.

C Effect] The thermal transfer recording medium of the present invention can be recorded (printed) on a recording sheet such as plain paper by the same method as known thermal transfer recording media.
For example, when a coloring material layer is melted by a thermal head, a thermally expandable substance is thermally expanded at the same time as the coloring material layer is heated, and this pressure causes the melted coloring material layer to be transferred to a recording sheet, which is a transfer medium with low smoothness. Make the transfer effective. In addition, when the thermally expandable material foams, the voids created by the foaming increase the releasability, making it possible to perform good printing even on paper with low slipperiness.

[Effects of the Invention] According to the present invention, in a heat-sensitive transfer recording medium in which a heat-fusible coloring material layer is laminated on a support, a heat-expandable substance-containing layer is provided between the supporting frame and the heat-melting coloring material layer. Since the structure is such that the layers are interposed, the above-mentioned technical problem of the present invention can be solved by the simple means of using a thermally expandable material.

[Example] Examples are given below, but the embodiments of the present invention are not limited thereto. In addition, "department" used below means "
Parts by weight.

Example 1 A thermally expandable material-containing layer coating solution having the following composition was applied onto a 5.3 gm thick polyethylene terephthalate film using a wire bar.

Coating liquid for thermally expandable substance-containing layer Polyvinyl butyral resin (BL-1 manufactured by Tsukushiki Kagaku Co., Ltd.) 10 parts Dinitropentamethylenetetramine 2.5 parts Methyl ethyl ketone 100 parts The thickness of the thermally expandable substance-containing layer after drying is approximately 18 J-m. there were. Next, the following coloring material layer coating liquid 41 was applied onto the thermally expandable substance-containing layer using a wire bar, and the coating was heated at 40°.
After drying at C, a thermal transfer recording medium sample (2) of the present invention was obtained. The dry film thickness of the coloring material layer was about 4 pm.

Coloring material layer coating liquid carbon black 10 parts Microcrystalline wax (manufactured by Mike OUHF BAREC: 0) 20 parts Montan wax (manufactured by Kato Yoko Co., Ltd.) 20 parts ethylene-ethyl acrylate resin (NUC-8070 manufactured by Nippon Unicar Co., Ltd.) 2 parts Toluene Using 120 copies of this thermal transfer recording medium sample (■), the applied power per heating element was 0.9 W using a thermal printer (a prototype machine equipped with a thin-film line thermal head with a heating element density of 8 dots/mm). The energy application time is 2 milliseconds! I then recorded it. Bond paper (Beck smoothness: 12 seconds) was used as the transfer paper. As a result, clear printing was obtained with no "fading" in the line drawings and no "white spots" in the solid black areas.

Example 2 A thermally expandable substance-containing layer coating solution having the following composition was applied onto a 5.3 gm thick polyethylene terephthalate film using a wire.

Coating liquid for layer containing thermally expandable substance polyvinyl butyral resin (BL-1 Manufactured by Block Chemical Co., Ltd.) 3 parts Honjo Monoester 2.5 parts Carphone black part 3 Methyl ethyl ketone 100 parts The thickness of the thermally expandable material-containing layer after drying was about i1.

Next, apply the following coloring material layer coating solution using a wire bar.
It was coated on the heat-expandable substance-containing layer -L and dried at 40°C to obtain a thermal transfer recording medium sample of the present invention. The dry film thickness of the coloring material layer was about 4 gm.

Coloring material layer coating liquid Carbon black 10 parts Carnauba wax 40 parts Ethylene-ethyl acrylate resin (NUC-nee 6070 manufactured by Nippon Unicar Co., Ltd.) 2 parts Toluene 120 parts Using this thermal transfer recording medium sample (■), the same procedure as in Example 1 was carried out. When printing was carried out, clear printing was obtained with no "fading" in the line drawings and no "white spots" in the flat black parts.

Comparative Example l Same as Example 1, 5.3+7. A resin layer to which dinitropentamethylenetetramine was not added was coated on a polyethylene terephthalate film having a thickness of m. After drying, a color material layer having the same composition as in Example 1 was applied so that the dry film thickness was about 4 p.m. After drying at 40°C, printing was carried out in the same manner as in Example 1, but "fading" occurred in the line drawings and "white spots" appeared in the solid black parts, resulting in prints that were difficult to read.

Comparative Example 2 Similarly to Example 2, a resin layer without 2.3.4-trihydroxybenzophenone-1,2-naphthoquinonediazide-4-sulfonic acid monoester was applied on a 5.31 Lm thick polyethylene terephthalate film. did. After drying, a color material layer having the same composition as in Example 2 was applied to a dry film thickness of about 4p.
It was applied so that it became Lm. After drying at 40°C, printing was carried out in the same manner as in Example 2, but "fading" occurred in the line drawing areas, and "white spots" appeared in the solid black areas, resulting in printing that was very difficult to see.

Patent applicant Konishiroku Photo Industry Co., Ltd. Agent: Patent attorney Nobuaki Sakaguchi (1 other person)

Claims (1)

[Claims] A thermal transfer recording medium comprising a heat-melting coloring material layer laminated on a support, characterized in that a layer containing a thermally expandable substance is interposed between the support and the heat-melting coloring material layer. recoding media.