JP2008094017A - Thermal transfer recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer recording medium with a back-coating layer (heat resistant lubricous layer) capable of being applied to a maintenance-free system (having self-cleaning properties), extending the life of a thermal head, exhibiting no fluctuation in heat conduction from the thermal head, and applicable to a fusion transfer process sensitive to fluctuation in heat conduction. <P>SOLUTION: The thermal transfer recording medium (A) provided with a thermal transfer layer (2) on one face of a substrate (1) and the heat-resistant sliding layer (3) on the other face, is characterized in that the heat-resistant sliding layer (3) comprises a thermoplatic resin, a reaction product of the thermoplastic resin with a polyfunctional isocyanate, or a radical reaction product using ultraviolet rays and electron beams as a trigger as a main component, a phosphate compound is incorporated as a lubricant, and a filler with a Mohs hardness of ≤4 and a mean particle diameter of ≤2 μm is incorporated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal transfer recording medium used in a thermal transfer type printer. More specifically, the present invention can be maintenance-free (has a self-cleaning property), improves the durability of the thermal head, and improves the thermal head. It has a back coat layer (heat-resistant slipping layer) that can be applied to melt transfer that is not sensitive to heat conduction and is sensitive to the heat conduction unevenness (if there is heat conduction unevenness, it appears as a rough surface in the printed matter). The present invention relates to a thermal transfer recording medium.

  Thermal transfer recording medium, that is, what is generally called a thermal ribbon, is an ink ribbon used in a thermal transfer printer. The thermal transfer method is a printing method in which the ink on the ink ribbon that contacts the head is melted or sublimated by the heat generated in the thermal head of the printer, and transferred to the transfer target.The transfer method and the difference in ink materials, etc. There are two methods: a melt transfer method and a sublimation transfer method.

  As shown in FIG. 2, the melt transfer method is a method for melting and transferring ink mainly composed of pigment-dispersed wax onto the surface of a transfer target (6) comprising a base substrate (5). It has excellent properties, light resistance, and versatility of transferred materials, and is used in word processors, barcode printers, ticketing systems, and so on. Further, as shown in FIG. 3, the sublimation transfer method uses a sublimation dye instead of the pigment, and is formed on the base substrate (5) by heating and pressurizing the thermal head (10). A sublimation dye is infiltrated into the image receiving layer (4), and since gradation expression is easy, it is used in full-color printers and video printers compatible with personal computers.

  By the way, the thermal transfer recording medium (A), that is, the thermal ribbon, becomes a base material (1), for example, a thermal transfer layer (2) on one side of a polyethylene terephthalate film (PET), and a printer on the other side. A back coat layer (heat resistant slipping layer) (3) is provided for adjusting the amount of heat applied from the thermal head (10) and the running performance of the head.

  The purpose of providing the back coat layer (heat-resistant slip layer) is as follows: (1) Maintenance-free (with self-cleaning) (2) Improving the durability of the thermal head (3) Uneven heat conduction from the thermal head It can also be applied to melt transfer that is sensitive to heat conduction unevenness (if there is heat conduction unevenness, it becomes rough and appears on the printed matter). Such a backcoat layer (heat-resistant slip layer) Development of a thermal transfer recording medium having the above has been demanded.

  For example, the base film has a heat-sensitive transfer layer on one side, a heat-resistant layer obtained by curing a synthetic resin that can be cured by heating with a curing agent on the other side, and a polyvinyl butyral resin, There has been proposed a heat-sensitive transfer sheet (see, for example, Patent Document 1) characterized in that a heat-resistant slip layer comprising a polyvalent isocyanate compound and a phosphate ester reaction product is provided. In particular, a combination of a resin and a phosphate ester has been proposed as a backcoat layer (heat resistant slipping layer). Although there is a description in the text that “addition of extender pigment may be preferable”, there is no specific limitation, and the action (purpose) in this case is clearly different. In other words, the prior art document aims to prevent sticking phenomenon (adhesion between the thermal head and thermal transfer sheet) and wrinkles, and to improve printability. The purpose is different.

Prior art documents are shown below.
JP 61-95989 A

  The present invention is intended to solve such problems of the prior art, is maintenance-free (has a self-cleaning property), improves the durability of the thermal head, and conducts heat from the thermal head. Thermal transfer recording medium having a back coat layer (heat-resistant slipping layer) that has no unevenness and can be applied to melt transfer that is sensitive to uneven thermal conduction (if there is uneven thermal conduction, it appears as a rough surface on the printed matter) The purpose is to provide.

  The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 of the present invention provides a thermal transfer layer (2) on one surface of a substrate (1) and the other surface. In the heat-sensitive transfer recording medium (A) provided with a heat-resistant slip layer (3), the heat-resistant slip layer (3) is a thermoplastic resin, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or an ultraviolet ray. Thermally sensitive transfer characterized by containing a radical reaction product triggered by an electron beam or an electron beam as a main component, containing a phosphate ester compound as a lubricant, and further containing a filler having a Mohs hardness of 4 or less and an average particle size of 2 μm or less. It is a recording medium.

  The invention according to claim 2 of the present invention is the heat-sensitive transfer recording medium according to claim 1, characterized in that the filler content in the heat resistant slipping layer (3) is 3 to 25% by mass. The thermal transfer recording medium according to claim 1.

  The thermal transfer recording medium according to claim 3 of the present invention is the thermal transfer recording medium according to claim 1 or 2, wherein the filler in the heat resistant slipping layer (3) comprises an inorganic mineral. It is.

  The invention according to claim 4 of the present invention is the thermal transfer recording medium according to any one of claims 1 to 3, wherein the thermal transfer layer (2) comprises a thermal sublimable dye and a binder. A thermal transfer recording medium characterized by being a layer.

  The invention according to claim 5 of the present invention is the heat-sensitive transfer recording medium according to any one of claims 1 to 3, wherein the heat-sensitive transfer layer (2) comprises a dye or / and a pigment and a binder. A heat-sensitive transfer recording medium characterized by being a transfer layer.

  The heat-sensitive transfer recording medium according to the present invention is a heat-sensitive transfer recording medium in which a heat-sensitive transfer layer is provided on one surface of a substrate and a heat-resistant slip layer is provided on the other surface. Alternatively, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam as a main component, a phosphate ester compound as a lubricant, a Mohs hardness of 4 or less, and an average particle size By containing a filler with a diameter of 2 μm or less, maintenance-free compatibility (with self-cleaning properties) is possible, the durability of the thermal head is improved, there is no uneven heat conduction from the thermal head, and the heat transfer is highly sensitive. It can also be applied to various melt transfer (if there is uneven heat conduction, it becomes rough and appears on the printed matter).

  An embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 1 is a side sectional view showing an embodiment of a layer structure of a thermal transfer recording medium according to the present invention.

As shown in FIG. 1, the thermal transfer recording medium of one embodiment of the present invention is provided with a thermal transfer layer (2) on one side of a substrate (1) and a heat-resistant slipping layer (3) on the other side. In the obtained thermal transfer recording medium (A), the heat-resistant slip layer (3) is a thermoplastic resin, a reaction product of a thermoplastic resin and a polyvalent isocyanate, or a radical reaction product triggered by ultraviolet rays or an electron beam. Is a thermal transfer recording medium characterized by containing a phosphate ester compound as a lubricant and further containing a filler having a Mohs hardness of 4 or less and an average particle diameter of 2 μm or less.

  Since the base material (1) is required to have heat resistance and strength that is not softened and deformed by heat pressure in thermal transfer, for example, polyethylene terephthalate, polyethylene naphthalate, polypropylene, cellophane, acetate, polycarbonate, polysulfone, polyimide, polyvinyl alcohol , Synthetic polyamide films such as aromatic polyamide, aramid, polystyrene, etc., and paper such as condenser paper, paraffin paper, etc. can be used alone or in combination, but the physical properties, processability, In view of cost and the like, a polyethylene terephthalate film is preferable. In addition, the thickness is in the range of 2 to 50 μm in consideration of operability and workability, but in consideration of handling properties such as transfer suitability and workability, the thickness is about 2 to 9 μm. preferable.

  Next, examples of the thermoplastic resin constituting the heat resistant slipping layer (3) include thermoplastic acrylic resins (polymethyl methacrylate, etc.), chlorinated rubber resins, vinyl chloride-vinyl acetate copolymer resins, and cellulose resins. Resins, chlorinated polypropylene resins, epoxy resins, polyester resins, nitrocellulose resins, styrene acrylate resins, polyether resins, polycarbonate resins and the like can be used alone or in combination. In consideration of wear resistance, animal waxes, plant waxes, mineral waxes, natural waxes such as petroleum waxes, synthetic hydrocarbon waxes, aliphatic alcohols and acid waxes, fatty acid esters and glycerite waxes, Hydrogenated wax, synthetic ketone wax, amine and amide wax, chlorinated hydrocarbon wax, synthetic animal wax, synthetic wax such as alpha-olefin wax, and metal salt of higher fatty acid such as zinc stearate What added the anti-friction agent can be used. Moreover, you may use an inorganic substance.

  Examples of the reaction product of a thermoplastic resin and a polyvalent isocyanate include, for example, a reaction product of a polyvinyl butyral resin and a diisocyanate, a reaction product of an acrylic polyol and a polyisocyanate, a reaction product of a polyester polyol and a polyisocyanate, and a urethane polyol. Reaction product of polyisocyanate, reaction product of polyester resin and polyisocyanate, reaction product of cellulose acetate resin and polyisocyanate, reaction product of nitrocellulose resin and polyisocyanate, reaction product of chlorinated rubber resin and polyisocyanate However, it is not limited to these.

Furthermore, examples of radical reactants triggered by ultraviolet rays or electron beams include monofunctional acrylates such as isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, and methoxypropylene glycol acrylate. And methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, alkyl methacrylate, tridecyl methacrylate, n-stearyl methacrylate, methoxyethylene glycol methacrylate, methoxypolyethylene glycol methacrylate Leh Monofunctional methacrylates such as cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, and benzyl methacrylate, bifunctional acrylates and methacrylates such as triethylene glycol diacrylate, polyethylene glycol diacrylate, and neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tris. Tri- or higher functional acrylate and methacrylate monomers such as acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate hexamethylene diisocyanate, pentaerythritol triacrylate tolylene diisocyanate And there may be mentioned radical reaction product obtained by reacting with the ultraviolet or electron beam is not limited thereto.

  Further, these acrylate monomers and methacrylate monomers may be used alone or in combination of two or more. In particular, in the case of a monofunctional acrylate monomer or methacrylate monomer, it is used by mixing with a bifunctional or higher acrylate monomer or methacrylate monomer. Moreover, you may mix and use with the organic compound which does not have other ultraviolet curing property or electron beam curing property.

  In addition, when the ultraviolet ray is used as a trigger, in addition to the acrylate monomer and the methacrylate monomer, a photoinitiator and an activator (benzoin type, acetophenone type, benzyl ketal type, ketone / amine type, etc.), and an auxiliary agent (polymerization inhibitor) , Wax, non-reactive polymer, etc.) and solvent (organic solvent such as ethyl acetate).

  Since such radical reactants are polymerized and cured by irradiating with ultraviolet rays or electron beams, they have a high film forming speed and do not require post-treatment such as aging.

  Next, the filler in the heat-resistant slip layer (3) is preferably made of an inorganic mineral, and the filler content is preferably 3 to 25% by mass.

  By the way, the Mohs hardness is an index relating to the hardness of an object, and the Mohs hardness of a typical filler material is as follows. For example, wax: 0.2, talc: 1, lead: 1.5, gypsum: 2, aluminum: 2.5, mica: 2.8, calcium carbonate: 3, meteorite: 4, apatite: 5, silica: 7, alumina: 9, diamond: 10, and other materials having a hardness of 4 or less include graphite, asphalt, calcium, gold, silver, copper, zinc, magnesium oxide, marble, antimony, and boric acid. In the present invention, Of these, talc, gypsum, and mica, which are fillers having a Mohs hardness of 4 or less and an average particle diameter of 2 μm or less, are preferable, and talc is particularly preferable. In addition, as for the thickness of the said heat resistant slipping layer (3), about 0.1-4 micrometers is preferable.

  Next, the heat-sensitive transfer layer (2) includes a heat-sensitive sublimation transfer layer comprising a heat-sublimable dye and a binder and a heat-sensitive melt transfer layer comprising a dye or / and a pigment and a binder.

  The ink for forming a heat-sensitive sublimation transfer layer is prepared, for example, by blending a heat sublimation dye, a binder, a solvent, and the like, and the amount of ink applied to this transfer layer is suitably about 1 μm (dry thickness).

  The ink for forming a heat-sensitive transfer layer is prepared by, for example, blending a pigment or / and a dye, a binder, a solvent, etc., and the coating amount in this case is suitably about 1 to 2 μm (dry thickness).

  A sublimation disperse dye is preferably used as the heat sublimation dye used in the heat-sensitive sublimation transfer layer forming ink. Examples of the binder include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate, and vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide. Resin, polyester resin, styrene / acrylonitrile copolymer resin, phenoxy resin, and the like. Among these, polyvinyl butyral, styrene / acrylonitrile copolymer resin, and phenoxy resin are preferable.

  Next, the dyes used in the heat-sensitive melt transfer layer forming ink include diarylmethane, triarylmethane, thiazole, methine, azomethane, xanthene, axazine, thiazine, azine, acridine Generally used thermal transfer dyes such as azo, spirodipyran, isodolinospiropyran, fluoran, rhodamine dactam, and anthraquinone can be widely used. Moreover, as a pigment, a well-known organic pigment and an inorganic pigment can be used. Examples of the binder include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, and cellulose acetate, and vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide. Resin, polyester resin, styrene / acrylonitrile copolymer resin, phenoxy resin, and the like. Among these, polyvinyl butyral, styrene / acrylonitrile copolymer resin, and phenoxy resin are preferable.

  Hereinafter, the thermal transfer recording medium according to the present invention will be described in more detail with specific examples, but is not limited thereto.

(Basic configuration)
<Base material>
Polyester film: Thickness 4.5μm
<Ink for forming a heat-sensitive sublimation transfer layer>
Magenta dye: 20 parts Butyral resin: 15 parts Polyester resin: 5 parts Toluene: 30 parts Methyl ethyl ketone: 30 parts <Ink for heat-sensitive melt transfer layer formation>
Magenta pigment: 10 parts Epoxy resin: 20 parts Carnauba wax: 10 parts Toluene: 30 parts Methyl ethyl ketone: 30 parts

<Example 1>
One of the substrates was coated with the following heat-resistant slip layer forming coating solution-1 by a gravure method with a dry thickness of 0.8 μm, and then cured in an oven at 50 ° C. for 24 hours. .
<Coating liquid for forming heat resistant slipping layer-1>
Butyral resin 5 parts Phosphoric acid ester compound 1 part Polyethylene wax (Mohs hardness 0.4 average particle size 1.8 μm) 3 parts Tolylene diisocyanate 2 parts Toluene 44 parts Methyl ethyl ketone 45 parts The filler content is about 27% by mass is there. Subsequently, the heat-sensitive sublimation transfer layer forming ink was printed on the other side of the substrate by a gravure method with a dry thickness of 1.0 μm to produce a heat-sensitive transfer recording medium of Example 1.

<Example 2>
The following heat-resistant slip layer forming coating solution-2 was applied to one of the substrates by a gravure method with a dry thickness of 0.6 μm, and then cured in an oven at 50 ° C. for 24 hours. .
<Coating liquid for forming heat resistant slipping layer-2>
Butyral resin 5 parts Phosphate ester compound 1 part Talc (Mohs' hardness 1 average particle size 1.0 μm) 1 part Tolylene diisocyanate 2 parts Toluene 45 parts Methyl ethyl ketone 46 parts The filler content is about 11% by mass. Subsequently, the heat-sensitive fusion transfer layer forming ink was printed on the other side of the substrate by a gravure method with a dry thickness of 1.0 μm to produce a heat-sensitive transfer recording medium of Example 2.

  A comparative example will be described below.

<Comparative Example 1>
The following heat-resistant slip layer forming coating liquid-3 was applied to one of the substrates by a gravure method with a dry thickness of 0.8 μm, and then cured by heating in an oven at 50 ° C. for 24 hours. .
<Coating liquid for forming a heat resistant slipping layer-3>
Butyral resin 5 parts Phosphoric acid ester compound 1 part Polyethylene wax (Mohs hardness 0.4 average particle size 3.0 μm) 3 parts Tolylene diisocyanate 2 parts Toluene 44 parts Methyl ethyl ketone 45 parts The filler content is the same as in Example 1. About 27% by mass. On the other side of the substrate, the heat-sensitive sublimation transfer layer forming ink was printed by a gravure method with a dry thickness of 1.0 μm to produce a heat-sensitive transfer recording medium of Comparative Example 1.

<Comparative example 2>
On one of the substrates, the following heat-resistant slip layer forming coating solution-4 was applied by a gravure method with a dry thickness of 0.8 μm, and then cured by heating in an oven at 50 ° C. for 24 hours. .
<Coating liquid for forming heat resistant slipping layer-4>
Butyral resin 5 parts Phosphate ester compound 1 part Silica (Mohs hardness 7 average particle size 1.8 μm) 3 parts Tolylene diisocyanate 2 parts Toluene 44 parts Methyl ethyl ketone 45 parts The filler content is about 27 as in Example 1. % By mass. On the other side of the substrate, the heat-sensitive sublimation transfer layer forming ink was printed by a gravure method with a dry thickness of 1.0 μm to prepare a heat-sensitive transfer recording medium of Comparative Example 2.

<Comparative Example 3>
One of the substrates was coated with the following heat-resistant slip layer forming coating solution-5 by a gravure method with a dry thickness of 0.6 μm, and then cured in an oven at 50 ° C. for 24 hours. .
<Heat-resistant slip layer forming coating solution-5>
Butyral resin 5 parts Phosphoric acid ester compound 1 part Silica (Mohs hardness 7 average particle size 1.4 μm) 1 part Tolylene diisocyanate 2 parts Toluene 45 parts Methyl ethyl ketone 46 parts The filler content is about 11% by mass. On the other side of the substrate, the heat-sensitive melt transfer layer forming ink was printed by a gravure method with a dry thickness of 1.0 μm to produce a heat-sensitive transfer recording medium of Comparative Example 3.

<Thermal transfer test>
The thermal transfer recording media obtained in Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to a 1000 m transfer test at 8 inches / s using a thermal simulator, and the state of the thermal head and the printed material after the test was visually observed. Observed. The results are shown in Table 1.

表１は、実施例１〜２および比較例１〜３の感熱転写記録媒体を用いてサーマルヘッドと印画物の状態を評価した結果を示す表である。

Table 1 is a table showing the results of evaluating the states of the thermal head and the printed material using the thermal transfer recording media of Examples 1-2 and Comparative Examples 1-3.

<Evaluation results>
As for the state of the thermal head, Examples 1 and 2 were satisfactory without any contamination. Comparative Example 1
Deposits were confirmed. In Comparative Examples 2 to 3, there was no deposit, but scratches were generated. As for the state of the printed matter, Example 1 was satisfactory with no defects. Example 2 was very good with no unevenness in the highlight area. In Comparative Examples 1 and 2, streaky omission occurred partially. In Comparative Example 3, transfer unevenness was confirmed in the highlight portion.

It is a sectional side view showing one embodiment of the layer structure of the thermal transfer recording medium according to the present invention. It is a sectional side view which shows one Example of a melt transfer system. It is a sectional side view which shows one Example of a sublimation transfer system.

Explanation of symbols

A ... thermal transfer recording medium 1 ... substrate 2 ... thermal transfer layer 3 ... heat-resistant slip layer 4 ... image-receiving layer 5 ... base substrate 6 ... transferred material 10 ... Thermal head

Claims (5)

  In a heat-sensitive transfer recording medium in which a heat-sensitive transfer layer is provided on one surface of a substrate and a heat-resistant slip layer is provided on the other surface, the heat-resistant slip layer is made of a thermoplastic resin, or a thermoplastic resin and a polyvalent isocyanate. It contains a reaction product or a radical reaction product triggered by ultraviolet rays or an electron beam as a main component, a phosphate ester compound as a lubricant, and a filler having a Mohs hardness of 4 or less and an average particle size of 2 μm or less. Characteristic thermal transfer recording medium.   2. The thermal transfer recording medium according to claim 1, wherein the content of the filler in the heat resistant slipping layer is 3 to 25% by mass.   3. The thermal transfer recording medium according to claim 1, wherein the filler in the heat resistant slipping layer is made of an inorganic mineral.   4. The thermal transfer recording medium according to claim 1, wherein the thermal transfer layer is a thermal sublimation transfer layer comprising a heat sublimable dye and a binder.   4. The thermal transfer recording medium according to claim 1, wherein the thermal transfer layer is a thermal melt transfer layer comprising a dye or / and a pigment and a binder.

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