JPS60225795A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To make it possible to favorably print in a wide range of smoothness of paper, by intermediately providing a rubber resin layer between a base and a heat-fusible coloring material layer. CONSTITUTION:A preferable rubber resin to be intermediately provided between the base and the heat-fusible coloring material layer has a modulus of elasticity at 50 deg.C of not higher than 1.0X10<8>Nm<-2>, preferably, 1.0X10<7>Nm<-2>. The thickness of the rubber resin layer is 0.5-5mum, preferably, 0.7-3mum, more preferably, 0.9-2mum. The rubber resin is preferably used in an amount of 50-100pts.wt., more preferably, 60-100pts.wt., per 100pts.wt. of the resin components of the resin layer. The rubber resin may be, for example, a natural rubber, a neoprene rubber, a polyisoprene rubber, a styrene-butadiene copolymer rubber, a butadiene-acrylonitrile copolymer rubber or a butyl rubber.

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.

[Prior Art] A thermal transfer recording medium has been conventionally used as a recording medium for transferring and forming an image on a recording sheet such as plain paper using a thermal printer, a thermal facsimile, or the like. This thermal transfer recording medium has at least one coloring material layer on a support, and the coloring material layer includes, for example, a layer containing a coloring agent made of a dye such as a pigment and a heat-fusible substance. etc. are known. In addition, films with excellent surface smoothness and dimensional stability are used as the support in order to obtain good reproducibility of the dye transfer image obtained from the color material layer coated on the support. There is.

When these conventional thermal transfer recording media print on various types of paper ranging from paper with low smoothness to paper with high smoothness, they can print well on paper with high smoothness, but they print on paper with low smoothness. This causes ``fading'' in the line drawings, and in the case of so-called solid black, ``white spots'' appear, making it extremely 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 JP-A-5B5.7-36698, etc.; , which is mainly intended for printing two or more times, and when printed on plain paper with low smoothness, ``fading'' and ``white spots'' occur as described above.

[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 smoothness range from paper with high smoothness to paper with low smoothness. The technical challenge is to

[Means for Solving the Problems] A thermal transfer recording medium of the present invention for solving the above-mentioned technical problem is a thermal transfer recording medium in which a heat-melting coloring material layer is laminated on a support. It is characterized in that a rubber resin layer is interposed between the heat-melting coloring material layer.

The present invention will be explained in more detail below.

The resin layer in the thermal transfer recording medium of the present invention contains a rubber resin as a main component.

As the rubber resin, ordinary polymers for rubber adhesives can be used. For example, natural rubber, neoprene,
Polyisoprene system, styrene-butadiene copolymer system,
Examples include butadiene-acrylonitrile copolymer systems, butyl rubber systems, and the like.

Especially natural rubber, cyclized rubber, polyisoprene, styrene.
Butadiene copolymers are preferred. In particular, the rubber resin preferable for the present invention has a Young's modulus of 1 and OX 10 N at 50°C.
m or less, more preferably 1. OX 10''Nm-'' or less.

The thickness of the rubber resin layer of the present invention is 0.5 to 5 mm, preferably 0.7 to 3 JLI11, more preferably 0.8 to 3 JLI11.
It is 2 m.

The resin layer t1 of the present invention may contain a resin other than the rubber-based resin, and the resin may be any resin as long as it has adhesion to the support and the coloring material layer, but polyvinyl butyral resin, ethylene -Ethyl acrylate resins, ethylene-vinyl acetate resins, epoxy resins, etc. generally give good results.

The rubber resin of the present invention is preferably 50 to 100 parts by weight, more preferably 60 to 1 part by weight, based on 100 parts by weight of the resin component of the resin layer.
It is preferable to add 0.00 parts by weight.

The method of incorporating the rubber-based resin of the present invention into the resin layer is arbitrary.

The heat-melting coloring material layer in the present invention mainly contains a low melting point substance,
- It consists of a coloring agent and a softening agent, and as a low melting point substance, a known heat-melting substance may be used without any particular restriction, but it is a combination of at least one type of hard wax and at least one type of soft wax. It is preferable to use them together.

The hard wax used in the present invention is 25°C (10(Ig
) is a wax having a penetration degree of less than 8. The measurement of penetration is based on JIS K 2530. And the melting point (purlin MPJ-2 type Nijo measurement value > 50-10
0'C! (7) Substances are preferred. Specific examples of the low quality waxes used in the present invention include: (1) ester waxes (natural ester waxes such as carnauba wax and montan wax; Hoechst Wax E manufactured by Hoechst;
F.

KP, KPS, BJ, OP, ON, X22. υ and 0
(synthetic ester waxes such as
7) NPS-9210, NPS-6115, PETR0NABA@G manufactured by Toyo Petrolite Co., Ltd., CARDIS
314 etc.), li low molecular weight polyethylene wax (
In particular, those with a molecular weight of 300-1000, such as POLYWAX 500IF3 and 655 manufactured by Toyo Petrolite),
- Low acid wax (Hoechst Wax manufactured by Hoechst)
S and LP, etc.).

On the other hand, the soft wax used in the present invention has a temperature of 25°C (to
It is a wax having a penetration degree of 8 or more in og). And melting point (measured value by Yanagiki MPJ-2 type) 50-1
00°C material is preferred. Specific examples of the soft wax used in the present invention include microcrystalline wax (Nisseki Microwax 155°180 (manufactured by 8 Hon Sekiyu Co., Ltd.), HI-WIG-1080, HI-MIC knee 2065° Hr-ur rc-2oa5). .Hx-src-
1070, HI-MIG-1045, +u-+uc-2
045 (manufactured by Nippon Seirosha), 5TARWAX 10
0. BE 5QUARE175.185. VICTO
RY, ULTRAFLEX (Toyo Vetrolite Co., Ltd.TM)
etc.), stearic acid, behenic acid, stearyl alcohol, white wax, beeswax, stearic acid door, stearone, sorbitan monostearate, polyoxyethylene monostearate, and the like. In addition, when hard wax and soft wax are used together, the composition ratio may be I:9 to 8:1, more preferably 2:8 to 8:2.

The coloring agent used in the present invention may be appropriately selected from conventionally known pigments, such as direct dyes, acid dyes, basic dyes, disperse dyes, and oil-soluble dyes (including metal-containing oil-soluble dyes). You can choose from. The dye used in the color material layer of the present invention may be any dye that can be transferred (transferred) together with a heat-fusible substance, so it may be a pigment in addition to those listed in L. In addition,
Specifically, the following can be mentioned. That is, as the yellow pigment, Kayalon Polyester Light Yellow 5G-3
(Nippon Kayaku), Oil Yellow 5-7 (white clay), Eisenspiron GRH Special (Hodogaya), Sumiplast Yellow FG (resident), Eisenspiron Yellow G
RH (Hodogaya) etc. are preferably used. Red pigments include Diaceritone Fast Red R (Mitsubishi Kasei), Diax Brilliant Trend BS-E (Mitsubishi Kasei), Sumipura Tread FB (Denjin), Sumipura Tread HFG (Dinen), Kayalon Polyester Pink RCL-E (Nippon Kayaku), Eisensviron Red G
EH Special (Hodogaya) etc. are preferably used. As blue pigments, Diaceritone Fast Brilliant Blue R (Mitsubishi Kasei), Dianic Sprue EB-E
(Mitsubishi Kasei), Kayalon Polyester Blue B-3F Conc (Nippon Kayaku), Sumiplast Blue 3R (Resident),
Sumiplast Blue G (Dweller) etc. are preferably used.

In addition, negative color pigments include /\Nza Yellow 3G, Taldrazine Lake, etc., and red pigments include Brilliant Carmine FB-Pure (Sanyo pigment), Brilliant Carmine 6B (11,1 positive pigment), Alizarin Lake, etc. is used, and the blue pigments include Cerulean Blue, Sumikablin Tocyanine Blue GN-0 (Dweller),
Phthalocyanine blue or the like is used, and carbon black, oil black or the like is used as the black pigment.

The colorant contained in the coloring material layer of the present invention is preferably a non-sublimable colorant, and as a non-sublimable colorant, it is transferred together with a heat-fusible substance to a recording sheet such as plain paper during heating recording. Any non-sublimable substance that can be used and has a color may be used.

It may be a substance that absorbs light at a wavelength of visible light (400r++s to 800nm) or a substance that forms a substance that absorbs in the visible light range, and is generally referred to as a dye, and is used as a thermal transfer recording medium. Among the synthetic dyes called dyes and pigments, natural dyes called animal dyes or vegetable dyes, etc., non-sublimable ones are 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.

The basic dye preferably used as the coloring agent of the present invention is, for example, crystal violet (C, 1°42555
), Malachite Green (G, 1.42000), Methyl Violet (G:, 1.42535), Victoria Blue (C, 1.44045), Mazienta (C
, 1,42510), triphenylmethane dyes,
Diphenylmethane dyes such as auramine (C, 1,855), astraphloxin FF (C, 1,48070)
, Eisenkatyron Yellow 3GLH (Hodogaya Chemical Industry Co., Ltd. product, C, 1,48055), Eisenkyriki Chiron Red 138H (C, 1,48020), Astrazone Golden Yellow GL (Bayer Inc. product, C,I).

Methine and azamethine dyes such as 48054), Rhodamine B (C, 1,451?0), Rhodamine 8
Xanthine dyes such as G (C, 1° 45160), Astrazon Blue-GL (C, 1, 11052), Astrazon Red F3BI.

Thiazole azo and triazole azo dyes such as (C, 1, 11055), Eisen Chiron Blue-5GH (
G.1. l1085), methylene blue (C,1,5
Structures of quinoneimine dyes such as Eisen Chiron Red GTu (c, 1.uos5), Cebron Yellow 3RL (DuPont product, C, 1, 11087), Astrazone Blue FGL (C;, 1.fl1512), etc. Examples include insulating azo dyes and anthraquinone dyes having an onium group at the end.

Oil-soluble metal complex dyes include, for example, symmetric l:2 type azo metal complex dyes, asymmetric l:2 type azo metal complex dyes, and l:2 type azo metal complex dyes.
: L-type azo metal complex dyes, azomethine metal complex dyes, formazan metal complex dyes, metal phthalocyanine dyes, and the presence of these dyes! Mention may be made of monobasic salts. Specifically, Eisenspironye o-3RH
(Hodogaya Chemical Co., Ltd. product, (:,, (, Solvent Yellow 25), f, t'n Fast Yellow R (BASF
company product, C, 1, 18890), Eisenspiron Orange 2R) l (C, 1, Solvent Orange 4o),
Pomelo Fast Scarlet B (C, 1, 12?83)
, Eisenspiron Red GEH (C, 1, Solvent Red 84), Zapon Fast Red BE (C:, r,
I27I5), Zapon Fast Violet BE (C
, 1,12196), Cyanine Blue BB (manufactured by Sumitomo Chemical Co., Ltd., C, 1,74160), Varifast Black 113804 (manufactured by Orient Chemical Co., Ltd., C, 1,12
185), Eisenspiron Yellow 3R) l Special (c, r, Solvent Yellow 25+1), Eisenspiron Orange 2RH Special (G, 1.Solvent Orange 40:I), Eisenspiron Blue-2
8NH (C:, I, Solvent Blue 11:i'),
Zapon Fast Blue HFL (C, 1,74350)
, Eisen Spiron Black BH Special (C1■,
Solvent black 22:1) and the like can be mentioned.

Acidic dyes include, for example, C,1, Acid Yellow 19,
C,1, Acid Red 37, C,1, Acid Blue 62, C,1, Acid Orange l01c-r, Acid Blue 83.0.1. Examples include Acid Black 01.

Direct dyes include G, 1. Direct Yellow 44, C1!
.

Direct Yellow 142, G, 1. Direct Yellow I2, C, 1, Direct Blue 15. G.1.
Direct Blue 25, G, I, Direct Blue 2
49, C, 1, Direct Red 8'1. C, 1, Direct Lead 8, G, 1. Direct Red 31, C
，! , Direct Black +54, C,! , Direct Black 17, etc.

The disperse dyes are C, 1, Disboose Yellow 5, G,
1. Disbors Yellow 51, G, 1. Disbors Yellow 64, G, 1. Disbo's Red 43, C
,1, Disbo's Red 54, C,1, Disbo's Red 135, C,1, Disbo's Blue 56, C,
1, Disboth Bluef 3, C, 1, Disboth 9
1st prize is mentioned.

The ballasted dyes used in the present invention are dyes having at least one ballast group in the dye matrix, such as azo dyes, alamethine dyes, anthraquinone dyes, naphthoquinone dyes, sterine dyes, quinophthalo dyes, and phthalocyanine dyes. Ballast groups are groups that are highly soluble in heat-melting substances, such as alkyl groups, cycloalkyl groups, aralkyl groups, alkoxy groups, alkylsulfonylamino groups, alkylsulfonyl groups, hydroxylalkyl groups, cyanoalkyl groups, alkoxycarbonylalkyl groups, and alkoxy groups. It is a group having an alkyl group or an alkylene group having 6 or more carbon atoms, such as an alkyl group or an alkylthio group. In particular, a ballast group having at least one alkyl group having 6 or more carbon atoms in the molecule is preferred. Examples of structures of ballasted dyes preferably used in the present invention include those described in the patent application (^) filed by the applicant on April 25, 1980, but the present invention is not limited thereto. .

The softener used in the present invention includes a low softening point polymer selected from ethylene-ethyl acrylate resin, ethylene-vinyl acetate resin, etc., preferably one having a softening point (measured value by ring and ball method) of 40 to 80°C. It will be done.

The composition ratio of the coloring material layer in the present invention is such that the content of the low melting point substance is 50 to 50%.
95% (weight%, same below) (more preferably 70-9
5%), colorant 5 to 20%, and softener 0 to 30% (more preferably 0 to 10%).

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. In order to obtain good thermal conductivity, the thickness of the support is generally not more than 60 μm, particularly preferably 2 to 20 μm. 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 rubber resin layer on a support such as a polymer film and a technique suitable for coating a heat-melting coloring material layer on a rubber resin layer are used. Techniques are known in the art and these techniques can also be used in the present invention. For example, the rubber resin layer (and the heat-melting color material layer) can be formed by hot-melt coating the composition, or by solvent coating a coating solution obtained by dissolving or dispersing the composition in an appropriate solvent. It is a layer. As a coating method for the rubber resin layer (and heat-fusible colorant layer) of the present invention, any known technique can be employed, such as a reverse roll coater method, an extrusion coater method, a gravure coater method, and a wire coater method. The heat-melting coloring material layer of the present invention may have a volume of 20 IL or less, more preferably 11-15 pL.

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 6.0×10 = ~25.0XlO″
4cal/see * c + am 'C) and has a high melting point. Many metals such as aluminum and copper are possible, and oxides such as tin oxide, aluminum oxide, magnesium oxide, titanium nitride, etc. Nitrides can also be used. The fine powder with high thermal conductivity of the present invention has a particle size of 3) z, m or less, more preferably 0.01 to 1 pLI6.
Good. For example, when incorporated into the rubber-based resin layer of the present invention, the mixing ratio of the resin and the fine powder is preferably such that the volume percentage of the fine powder is 10 to 80%, more preferably 20 to 60%.
%.

The highly thermally conductive fine powder is preferably dispersed and contained in the rubber-based resin layer, but may also be contained in the support and/or the colorant layer.

The heat-sensitive transfer recording medium of the present invention may have other constituent layers such as an undercoat layer (for example, a layer for improving film adhesion) and an overcoat layer (for example, a layer made of a heat-melting substance). good.

[Function] 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 heated with a thermal head, the coloring material layer melts, and this melted coloring material layer is effectively transferred to the recording sheet, which is the short object to be transferred, by the rubber elasticity of the rubber resin layer, thereby creating a smooth surface. It becomes possible to perform good printing even on paper with low strength.

[Effects of the Invention] According to the present invention, in a heat-sensitive transfer recording medium in which a heat-melting coloring material layer is laminated on a support, a rubber-based resin layer is interposed between the support and the heat-melting coloring material layer. Since the configuration was
The above-mentioned technical problem of the present invention can be solved by the simple means of using a rubber-based resin.

[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 coating solution having the following composition was applied onto a 5.3 pm thick polyethylene terephthalate film using a wire bar so that the dry temperature was 14°C to obtain a rubber resin layer.

200 parts of rubber resin layer coating liquid toluene After drying, apply the following coloring material layer coating liquid using a wire bar.
After coating to a dry film thickness of 3 thick, the mixture was heated in a dryer at 60° C. for 20 minutes to obtain a thermal transfer recording medium sample (2) of the present invention.

Coloring material layer coating liquid Carbon black 10 parts Microcrystalline wax (Micro tlHF manufactured by BARECO) 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 120 parts Using this thermal transfer recording medium sample (■), a thermal printer (prototype machine equipped with a thin-film line thermal generator with a heating element density of 8 dots/m) was used to print a sample with an applied power of 0.6 W per heating element. Recording was performed by applying energy for an application time of 1 millisecond. As the transfer paper, pound paper (Beck smoothness: 12 seconds) was used. As a result, clear printing was obtained with no "fading" in the line drawings and no "white spots" in the solid black areas.

Comparative Example 1 In Example 1, only a heat-fusible coloring material layer having the same composition as above was applied and heated in a dryer at 60° C. for 20 minutes to obtain a comparative thermal transfer recording medium sample (2). The dry film thickness was 3 layers. This sample f was printed using the same thermal printer as in Example 1 on pound paper (Beck smoothness: 12 seconds).

As a result, ``fading'' occurred in the line drawings, and ``white spots'' appeared in the solid black areas, resulting in prints that were extremely difficult to read.

Comparative Example 2 A comparative thermal transfer recording medium sample I was obtained in the same manner as in Example 1 except that polyvinyl butyral was used instead of polybutadiene. The dry thickness of the resin layer was 11. This sample (3) was printed in the same manner as in Example 1, 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. Representative: Nobuaki Sakaguchi (and one other person)

Claims (1)

[Claims] A heat-sensitive transfer recording medium comprising a heat-fusible coloring material layer laminated on a support, characterized in that a rubber-based resin layer is interposed between the support and the heat-fusible coloring material layer. .