JPS60253587A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To make it possible to obtain good printing in a wide smoothness degree, by containing a fine particular filler in the heat-meltable surface layer applied onto a heat-meltable colorant layer. CONSTITUTION:A heat-meltable surface layer is applied onto a heat-meltable colorant layer and contains a fine particular filler. The fine particulated filler is an org. or inorg. fine particle or powder with a particle size of 0.01-100mum, pref., 0.1-10mum. A white or colorless transparent or translucent one is pref. from the aspect of the prevention of background staining. The colorant layer and the surface layer are melted when heated corresponding to image information by a thermal head but, because the fine particulate filler added to the heat- meltable surface layer in the side near to paper to be transferred fills the recessed parts on the surface of the paper to be transferred along with the heat- meltable substance to smooth the surface of said paper to be transferred and the colorant layer is made easily transferrable to the paper to be transferred, printing quality having good printing density and reduced in the formation of a defective image is obtained.

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 heat-sensitive transfer recording medium has at least one heat-melting coloring material layer on a support, and the heat-melting coloring material layer includes, for example, a coloring agent made of a pigment such as a pigment, and a heat-melting coloring material layer. A layer containing a sexual substance is known. In addition, in order to obtain good reproducibility of the dye transfer image obtained from the heat-melting color material layer coated on the support, films with excellent surface smoothness and dimensional stability are used. It 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, 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.

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

[Means for Solving the Problems] The thermal transfer recording medium of the present invention for solving the above-mentioned technical problem is a thermal transfer recording medium having a heat-fusible coloring material layer on a support. A heat-fusible surface layer is coated on the material layer 1-, and the heat-fusible surface layer contains a fine particle filler.

A preferred embodiment of the present invention is that the particulate filler is white, colorless transparent, or colorless semitransparent fine particles or fine powder.

The present invention will be explained in more detail below.

The particulate filler of the present invention is contained in the heat-fusible surface layer coated on the seventh part of the heat-fusible coloring material layer. The heat-fusible surface layer is a layer that does not substantially contain a colorant and is partially or completely transferred to the receiving paper by heat during recording (printing), and is a layer that does not contain a heat-fusible substance as a main component. This is the layer where

The particulate filler used in the present invention is organic or inorganic and has a diameter of 0.01 to 100 μm, more preferably 0.1 to 10 g.
They are fine particles or fine powders having a particle size of m, and particularly preferred are those in which the fine particle filler is white, colorless transparent, or colorless translucent fine particles or fine powder. Preferred specific examples include: white carbon; oxides such as alumina, zinc oxide, and magnesium oxide; carbonates such as calcium carbonate, magnesium carbonate, and zinc carbonate; kaolin clay, pyrophyllite, talc, and sericite; silicate minerals,
Sulfates such as barium sulfate, calcium sulfate, aluminum sulfate, etc.; Organic polymer fine particles or fine powders such as urea resin, phenol resin, polystyrene resin, and acrylic resin.

In addition to the above, colored fine particles or fine powders other than white may be used, but from the viewpoint of preventing background smearing (fogging), white, colorless transparent, or colorless translucent particles as described in "2" are preferred.

These may be used alone or in combination of two or more.

The particle size of the particulate filler used in the present invention is 0.01 to 100 μm, more preferably 0.1 to 10 μm, as described above.
When using a fine particle filler having a particle size of 0,000 gm and a particle size of 0, Ol p, m or more, the fine particle filler fills the four parts of the surface of the transfer paper, smoothing out the surface irregularities of the transfer paper. On the other hand, from the viewpoint of good film properties of the heat-melting colorant layer and improvement of printing quality, 100pLI11*
Preferably, a full particulate filler is used. Incidentally, the particulate filler may be contained in a state in which a portion thereof protrudes from the heat-fusible surface layer.

The particulate filler of the present invention may be incorporated into the heat-fusible surface layer by any method, such as uniformly dispersing it in the heat-fusible material using an organic solvent. Examples of organic solvents include toluene, isopar, xylene, ethyl acetate, etc.
In addition, any material may be used as long as it can be dispersed in a heat-fusible substance without melting the particulate filler of the present invention.

When the particulate filler used in the present invention forms strong aggregates, the transferability of the heat-fusible surface layer decreases. Various surfactants can be used to prevent this. Examples of surfactants that are preferably used include those described in Japanese Patent Application No. 59-91112 filed by the present applicant.

The heat-melting substance which is the main component other than the fine particle filler in the heat-melting surface layer has the same meaning as the low-melting point substance or low-softening point substance mentioned in the description of the heat-melting coloring layer below, and It may be selected from the heat-melting substances listed in the description of the heat-melting coloring material layer. The heat-melting substance in the heat-melting surface layer may be the same as or different from the heat-melting substance in the heat-melting coloring material layer described later.

The content ratio of the particulate filler of the present invention to the heat-fusible substance is 1 to 80% (by weight, the same hereinafter), preferably 5 to 4%.
It is 0%. The effects of the present invention can be seen with a content ratio of 1% or more, while a content ratio of less than 80% is preferable in terms of improving film properties and preventing cracking, film peeling, etc.

The heat-fusible colorant layer in the present invention may be any colorant-containing layer that is partially or entirely transferred to the transfer paper by heat, and examples of the composition of the colorant layer include heat-fusible substances (low The main components are a substance with a melting point or a substance with a low softening point), a coloring agent, and a softening agent.

The heat-melting substance used in the present invention has a melting point (measured by Yanagimoto MPJ-2 type) or a softening point (measured by the ring and ball method) of 40 to 120°C, more preferably 60 to 120°C.
It is a solid or semi-solid substance at 0°C, and specific examples include vegetable waxes such as carnauba wax, wood wax, auriculie wax, and esparto wax, and animal waxes such as beeswax, insect wax, shellac wax, and spermaceti wax. In addition to waxes such as petroleum waxes such as paraffin wax, microcrystalline wax, ester wax, and liquefied wax, and mineral waxes such as montan wax, osikerite, and ceresin;
Higher fatty acids such as palmitic acid, stearic acid, margaric acid, and behenic acid; Higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol, and eicosanol; cetyl palmitate, myricyl palmitate, and cetyl stearate , higher fatty acid esters such as myricyl stearate; amides such as acetamide, propionic acid amide, palmitic acid amide, stearic acid amide, amide wax; ester gum, rosin maleic acid resin,
Rosin conductors such as rosin phenolic resin and hydrogenated rosin;
Polymer compounds such as phenol resins, terpene resins, cyclopentadiene resins, and aromatic resins; Higher amines such as stearylamine, behenylamine, and palmitinamine; Polyethylene oxides such as polyethylene glycol 4000 and polyethylene glycol 6000. , these may be used alone or in combination of two or more. Among these, higher amides such as palmitic acid amide, stearic acid amide, oleic acid amide, and amide wax are particularly preferred. Also, JP-A-54-682
The "thermofusible solid component that is solid at room temperature" described in Japanese Patent Publication No. 53 and the "vehicle" described in JP-A-55-105579 may also be used. Among the heat-melting substances used in the coloring material layer, it is particularly preferable to use a combination of hard wax and soft wax (one or more types of each, h) as the low-melting substance. Hard wax [25°C
Examples of waxes with a penetration degree (according to JIS K 2530) of less than 8 in IQOg are: ■Ester waxes (natural ester waxes such as carnauba wax and montan wax, and Hoech manufactured by Hoechst);
st wax E, F.

KP, KPS, BJ, OP, OM, X22. U and 0
(synthetic ester wax, etc.), (wax obtained by oxidizing wax such as paraffin wax and microcrystalline wax, NPS-111210, NPS-8115 manufactured by Hiki Seiro Co., Ltd., manufactured by Toyo Petrolite Co., Ltd. PETR0NABA-C, CARDIS
314, etc.), ■Low molecular weight polyethylene wax (particularly those with a molecular weight of 300 to 1000, such as POLYWAX 500 and 655 manufactured by Toyo Vetrolite), ■Acid wax (HoechstWax S and LP manufactured by Hoechst)
etc.) etc. Also, soft wax [2
Penetration (JIS K 2) at 5° (! (100g)
According to 530. ) is 8 or more] Examples of microcrystalline waxes (Kuiteishi Microwax 155, 180 (manufactured by Nippon Oil Co., Ltd.), Hl-MI
C-1080,)II-MIC-2065,)II-M
IC-20!35゜Old-Old C-1070. old-+ucf
toa5. Old - TC Knee 2045 (manufactured by Hiki Seirosha)
, 5TARWAX 100. BE 5QUARE
175,185°VTCTORY, ULTRAFLEX
(manufactured by Toyo Petrolite Co., Ltd.), stearin, behenic acid, stearyl alcohol, white wax, beeswax, F-decyl stearate, stearon, sorbitan monostearate, polyoxyethylene monostearate, or Diacarna 30 and tires. Examples include Karna PA30L (manufactured by Mitsubishi Kasei Corporation). In addition, when using a combination of such hard wax and soft wax, the weight ratio used is 1:8 to 9:1 (more preferably 2:
8 to 8:2) is sufficient.

The colorant to be contained in the heat-melting color material layer of the present invention may be appropriately selected from dyes and pigments. Examples of dyes include basic dyes, oil-soluble dyes (including oil-soluble metal complex dyes), and acidic dyes. You can choose from dyes, direct dyes, disperse dyes, etc. These dyes may also be pallast dyes. On the other hand, as the pigment, in addition to organic pigments such as phthalocyanine pigments, inorganic pigments such as carbon black can be used.

The coloring agent to be contained in the heat-melting coloring material layer of the present invention is particularly preferably non-sublimable, and as a non-sublimating colorant, it is necessary to add a heat-melting substance to a recording sheet such as plain paper during heating recording. Any non-sublimable substance that can be transferred 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 (C, I).

42555), malachite green (C, 1,4200
0), methyl violet) (C, 1,42535)
, Victoria Blue (C, 1, 44045), triphenylmethane dyes such as Mazienta (C, 1, 42510), diphenylmethane dyes such as Auramine (C, 1, 655), Astraphloxin FF (C, 1, 4
8070), Eisenkatyron Yellow 3GLH (Hodogaya Chemical Co., Ltd. product, C, 1,48055), Eisenkatyron Red flBH (C, 1,18020), Astrazone Golden Yellow GL (Bayer Inc. product, C
, 1°48054), xanthine dyes such as Rhodamine B (C:, 1.45170), Rhodamine 6G (C:, 1°45160), Astrazonpur-GL (C :, 1.1105
2), Astrazone Red F3BL (C, 1,110
55) and other thiazole azo and triazole azo dyes, Eisenryoku Chiron Blue-50) 1 (C, 1,110
85), quinoneimine dyes such as methylene blue CC, 1,52015), Eisen Chiron Red GTLH
(C, 1, 11085), Cevron Yellow 3RL (
Examples include insulating azo dyes and anthraquinone dyes having an onium group at the structural end, such as DuPont product C, 1, 11087) and Astrason Blue FGL (C, 161512).

Oil-soluble metal complex dyes include 1, for example, symmetrical 1:2 type azo metal complex dye, asymmetric 1=2 type azo metal complex dye #1,
Examples include l:l type azo metal complex dyes, azomethine metal complex dyes, formazan metal complex dyes, gold m-y talocyanine dyes, and organic base salts of these dyes. Specifically, Eisenspiron Yellow 3RH
(Hodogaya Chemical Co. product, c, r, solvent yellow 2
5), Zapon Fast Yellow R (BASF product, C
, 1, 18890), Eisensbiron Orange 21'
1) I (C, 1, Solvent Orange 40), Pomelo Fast Scarlet B (C, 1, 12783), Eisenspiron Red GEH (C, 1, Solvent Red 8)
4), Zapon Fast Red BE (C, 1, 12715
), Iolet BE to Zapon Fast 7 (C, 1, 1
219B), cyanine blue BB (Sumitomo Chemical product,
C, 1,74180), Varifast Black 1380
4 (Orient Chemical Company product, C, 1, 12195), Isenspiron Yellow 3RH Special (G, I
, Solvent Yellow 25:1), Eisenspiron Orange 2RH Special (C, 1, Solvent Orange 40:1)-, Eisensviron Blue-28NH (
C, I, Solvent Blue-117), Zapon Fast Blue) IFL (C, 1, 74350), Eisens Viron Black BH Special (C, 1, Solvent Black 220), and the like.

Acidic dyes include, for example, C,1, Acid Yellow 19,
C, 1, Acid Red 37, G, 1. Acid Blue B2, C, R, Acid Orange 10. C,1,
Examples include Acid Blue 83, C,1, Acid Black 01, and the like.

The direct dye is C,1, Direct Yellow 44, C,1
゜Direct Yellow 142, C, 1, Direct Yellow 12, G, 1. Direct Blue 15, C, 1,
Direct Blue 25, C, 1, Direct Blue 24
9, C, 1, Direct Red 81. C,1, Direct Red 9, C,1, Direct Red 31, C,1
, Direct Black 154, C,1, Direct Black 17, and the like.

Disperse dye is C,1, Disboose Yellow 5,C,1
, Disbo's Yellow 51. C, 1, Disbo's Yellow 84, C, 1, Disbo's Red 43, C,
1, Disbo's Red 54. C,1, Disbo's Red 135, C,1, Disbo's Blue 58. C
, 1, Disbo's Bluef 3, C,1, Disbo's 81, and the like.

The ballasted dyes used in the present invention are dyes having at least one ballast group in the dye matrix, such as azo dyes, azomethine dyes, anthraquinone dyes, naphthoquinone dyes, sterine dyes, quinophthalo pigments, and phthalocyanine dyes. Examples of ballast groups include groups that are highly soluble in heat-fusible substances such as alkyl groups, cycloalkyl groups, aralkyl groups, alkoxy groups, alkylsulfonylamino groups, alkylsulfonyl groups, hydroxylalkyl groups, cyanoalkyl groups, and alkoxycarbonylalkyl groups. , an alkyl group having 6 or more carbon atoms, such as an alkoxyalkyl group, an alkylthio group, or an alkylene group. In particular, a ballast group having at least one alkyl group having 6 or more carbon atoms in the molecule is preferable. Examples of the structure of the ballast dye preferably used in the present invention include the structure described in Japanese Patent Application No. 81688/1988 filed by the present applicant. Examples include things such as
The present invention is not limited thereto.

It is preferable that the heat-melting color material layer of the present invention contains a softener. The softener used in the present invention preferably has a softening point (measured by the ring and ball method) of 40 to 200°C, and either a hydrophilic polymer or a hydrophobic polymer can be used. Examples of hydrophilic polymers include gelatin, gelatin derivatives, cellulose derivatives, proteins such as casein, natural products and natural product derivatives such as polysaccharides such as starch, water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and acrylamide polymers. Examples include synthetic water-soluble polymers such as polyvinyl compounds, and vinyl-based and polyurethane-based polymer latexes. As a hydrophobic polymer, U.S. Patent No. 3.142
, No. 588, No. 3,143,386, No. 3,062.
f3?4, 3,220,844, 3,287.
Examples include the synthetic polymers described in No. 289 and No. 3,411,911. Preferred polymers include polyvinyl butyral, polyvinyl formal, polyethylene, polypropylene, polyamide, ethyl cellulose, cellulose derivatives such as cellulose acetate, polystyrene, polyvinyl acetate, polyvinyl chloride,
Polyvinylidene chloride, ethylene-ethyl acrylate,
Ethylene-vinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl-vinyl acetate-maleic acid terpolymer, acrylic resins such as polymethyl methacrylate, polyisobutylene, rosin derivatives such as ester gum, petroleum resin, coumaron indene Examples include resin, cyclic rubber, and chlorinated rubber. In the present invention, one or a combination of two or more of these softeners may be used.

Although the composition ratio of the heat-melting coloring material layer of the present invention is not limited,
- 50 to 95 parts (more preferably 70 to 85 parts) of the heat melting substance and 5 to 20 parts of the coloring agent relative to 100 parts (parts by weight, the same applies hereinafter) of the total solid content of the heat melting coloring material layer. , the softener is 0 to 30 parts (more preferably 1 to 10 parts).

The heat-melting 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, and olive oil, animal oils such as whale oil, and mineral oils are preferably used. It's fine. However, in the present invention, the content of the additives other than the above-mentioned main components is preferably less than 50% by weight.

The support used in the thermal transfer recording medium of the present invention preferably 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 mm or less, especially 2 to 20 mm thick, in order to obtain good thermal conductivity.
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 heat-sensitive transfer recording medium of the present invention, techniques suitable for applying the heat-fusible colorant layer and the heat-fusible surface layer to a support such as a polymer film are known in the art, and these known techniques may be used. can also be applied to the present invention. For example, the hot-melt colorant layer and the hot-melt surface layer are 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 heat-melting color material layer and heat-melting surface layer of the present invention, any technique such as a reverse roll coater method, an extrusion coater method, a gravure coater method, a wire bar coating method, etc. can be adopted. The heat-melting coloring material layer of the present invention may have a thickness of 207 gm or less, more preferably 1 to 15 gm. Further, the heat-fusible surface layer of the present invention preferably has a thickness of 5JL11 or less, particularly 0.01 to 3JLm.

The thermal 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 intermediate layer.

[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.
This makes it possible to perform good printing even on paper with low smoothness. Although the reason is not necessarily clear, it is inferred as follows. That is, for example, when heated with a thermal head according to image information, the heat-melting coloring material layer and the heat-melting surface layer are dissolved, but the fine particle filling added to the heat-melting surface layer on the side closer to the transfer paper The agent fills the irregularities on the surface of the transfer paper together with the heat-fusible substance, smoothing out the surface irregularities, and thereby making it easier for the heat-fusible colorant layer to be transferred to the transfer paper, thereby improving the printing quality. The concentration is "Niri"
It is thought that this provides good print quality with less white spots.

[Effects of the Invention] According to the present invention, in a heat-sensitive transfer recording medium having a heat-melting coloring material layer on a support, a heat-melting surface layer is coated on the heat-melting coloring material layer. Since the heat-fusible surface layer is configured to contain a fine particle filler, the above-mentioned technical problem of the present invention can be solved.

[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 heat-fusible coloring material layer coating solution having the following composition was coated on a polyethylene terephthalate film having a thickness of 5.3 JLm using a wire.

Heat-melting coloring material layer coating liquid Carbon black 5 parts Polyethylene wax (Weissen 0252c
8 parts microcrystalline wax (Micro-U) IF manufactured by BARECO) (melting point 65°C) (Melting point 65°C)
) 20 parts ethylene-ethyl acrylate resin (NUC-
6070 manufactured by Nippon Unicar Co., Ltd.) (softening point 85°C) 2 parts xylene 65 parts After coating, drying at 60°C, a thermal transfer recording medium sample (comparison) having a heat-melting coloring material layer with a film thickness of 3 pm was prepared. Obtained.

Next, using the above sample (1), the following heat-melting surface layer coating liquid (A) was applied thereon.

Heat-melting surface layer coating liquid (A) Montan wax (manufactured by Kato Yoshiyuki Co., Ltd.) (melting point 80°C) 10 parts Calcium carbonate (TP-222H3 manufactured by Okutama Kogyo Co., Ltd.) (average particle size l~
2km) 40°C after applying 90 parts of 2 parts Isopar (Isopar G manufactured by Esso Oil Co., Ltd.)
A heat-sensitive transfer recording medium sample (2) (invention) having a heat-melt surface layer having a thickness of 2 pm on the heat-melt coloring material layer (1) was obtained.

On the other hand, apply the following heat-melting surface layer coating solution (
B) was applied.

Heat-melting surface layer coating liquid (B) Montan wax (manufactured by Kato Yoko Co., Ltd.) (melting point 80°C) 10 parts Isopar (Isopar Q manufactured by Esso Oil Co., Ltd.) 90 parts 40°C after coating
Blow drying is performed to form a film with a thickness of 2 on the heat-melting coloring material layer.
A thermal transfer recording medium sample (comparison) having a heat-melting surface layer of p and ta was obtained.

Each of these thermal transfer recording medium samples (1), (2), and (2) were tested as follows.

High sensitivity thermal printer (heating element density 8do L/
A prototype machine equipped with a mm thin film type line thermal head.

), the applied power per heating element was 0.9 W, the application time was 2 milliseconds, and the energy was increased by 4 for recording. Bond paper (penk smoothness 12sec) is used as transfer paper.
) was used. The resolution, background smudge (fog), and transferability were evaluated using the following methods.

(Resolution) The alphabet was printed, and the printed portion was observed with a 25x magnifying glass. As a result, Samples (1) and (2) had white spots in the thin line areas, and the print was faded. However, sample (■) had no white spots and a clear print was obtained.

(Background stains (fog)) Various kanji characters were printed and stains other than the printed areas were observed using a magnifying glass. As a result, sample ■ had some scumming, but
■ and ■ had no background stains at all.

(Transferability) Solid black printing was performed and the optical reflection density was measured.

As a result, Samples (1) and (2) had a value of 0.5 or more (2) and had many white spots, but Sample (2) had a value of 1.0 and had no white spots at all.

Patent applicant Konishiroku Photo Industry Co., Ltd. Representative Patent Attorney Nobuaki Sakaguchi (1 other person)

Claims (2)

[Claims] (1) In a heat-sensitive transfer recording medium having a heat-melt coloring material layer on a support, a heat-melting surface layer is coated on the heat-melting coloring material layer, and the heat-melting surface layer is coated on the heat-melting coloring material layer. A thermal transfer recording medium characterized in that it contains a fine particle filler. (2) The thermal transfer recording medium according to claim 1, wherein the fine particle filler is white, colorless transparent, or colorless translucent fine particles or fine powder.