JP2003312152A - Hot melt transfer recording medium having protective layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot melt transfer recording medium for imparting good protective performance on an image formed by a thermal transfer mobile printer on an image receiver. <P>SOLUTION: The hot melt transfer recording medium comprises: a color ink layer containing a wax as a main component; a heat transferable protective layer having a protective layer and an adhesive layer laminated in this order on the support. In this medium, the main component resin of the protective layer is a resin of one type selected from the group consisting of acrylic resin, cellulose resin and polyvinylbutyral resin. The adhesive layer contains an ethylene vinylacetate copolymer, and/or an ethylene ethylacrylate copolymer as main components, and the wax. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of forming a full-color image by thermal fusion transfer and forming a protective layer made of resin on the image by thermal fusion transfer. In particular, in a full-color image forming system for a mobile printer, a full-color image is formed using a color heat-melt transfer recording medium containing wax as a main component, and a low-power printer such as a battery drive is formed on the image. This is a technical field of forming a protective layer by thermal fusion transfer.

[0002]

2. Description of the Related Art Conventionally, when a protective layer made of a resin is formed by thermal fusion transfer on a full-color image formed by using a color thermal fusion transfer recording medium whose main component is a low-energy wax, it is made of resin. An excessive amount of heat is required for the fusion transfer of the protective layer, and the thermal energy during thermal fusion transfer of the protective layer causes the transfer dots of the image formed from the wax to re-melt and cause crushing, resulting in image distortion. Was occurring. Further, the adhesiveness between the protective layer made of resin and the color ink layer made of wax is poor, and a good overprint effect cannot be exhibited, which is a factor of uneven gloss. Further, when a binder containing wax as a main component was used for the protective layer, transfer with low energy was possible, but sufficient scratch resistance could not be obtained, and attention was required in handling the image.

[0003]

A method of forming a protective layer made of a resin by heat-melt transfer on a full-color image formed by using a color heat-melt transfer recording medium containing a low energy compatible wax as a main component. The present invention provides a heat-melt transfer recording medium having a highly scratch-resistant protective layer made of a resin that does not cause image crushing and can obtain a good gloss image.

[0004]

SUMMARY OF THE INVENTION The present invention provides a thermal melt transfer recording medium in which a color ink layer containing a wax as a main component and a thermal transferable protective layer are provided on a support in a frame-sequential manner. The above problems are solved by adopting the following configuration. That is, according to the present invention, (1) a color ink layer containing wax as a main component is provided on a support, and a thermal transferable protection layer in which a protection layer and an adhesive layer are laminated in this order on the support is provided in a frame order. In the heat-melt transfer recording medium, the main component resin of the protective layer is a resin selected from at least one kind of acrylic resin, cellulose resin and polyvinyl butyral resin, and the adhesive layer is ethylene vinyl acetate copolymer and / or ethylene ethyl Provided is a heat-melt transfer recording medium containing an acrylate copolymer as a main component and a wax.

Further, the present invention provides (2) a heat-melt transfer recording medium characterized in that the protective layer contains a silicone-modified resin.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

When an image is formed on a color thermal fusion transfer recording medium using a mobile printer, it is necessary to thermally transfer the color ink with a small amount of electric power. For this reason, the color ink has a constitution of a color heat-melt transfer recording medium containing wax having a small heat capacity of fusion for each color as a main component. Here, the mobile printer refers to a thermal printer that is small and lightweight and is driven by a portable battery.

As the color heat-melt transfer recording medium containing the above-mentioned wax as a main component, an ordinary known wax-based color heat-melt transfer recording medium can be used. The constitution is such that a heat-fusible color ink layer is provided on a support, and a heat resistant treatment layer made of a silicone-containing resin is provided on the opposite surface.

As the support, various supports known as conventional heat-melt transfer supports are used.
A polyester film having a thickness of 2 to 6 μm is particularly preferable in terms of heat transfer property and cost. In particular, a polyester film having a thickness of 2 to 4.5 μm is more preferable for a mobile printer with low power consumption and small size.

The hot melt ink component comprises wax and a colorant. Examples of the waxes include natural waxes such as wood wax, carnauba wax, candelilla wax, montan wax and ceresin wax, petroleum waxes such as paraffin wax and microcrystalline wax, synthetic waxes such as oxide wax and ester wax, Higher fatty acids can be used. As the colorant, various known pigments and known dyes can be used, and examples thereof include azo-based, phthalocyanine-based, quinacridone-based, thioindigo-based, anthraquinone-based, isoindoline-based and carbon black pigments. These can be used in combination of two or more kinds. If necessary, a thermoplastic resin may be added for the purpose of adjusting the melt viscosity. Examples of the thermoplastic resin include olefin copolymers such as ethylene-vinyl acetate copolymer, polyamide resins, polyester resins, natural rubber, petroleum resins, rosin resins, and styrene resins. In addition to this, a filler such as silica, silicone oil, a fluorine-based surfactant, or other lubricant may be blended in order to prevent blocking and stains.

The thickness of the color ink layer is 0.3 to
2.0 μm is preferable from the viewpoint of image formation and sensitivity, and particularly for mobile printers, 0.3 to 1.0 μm is more preferable. If the thickness is less than 0.3 μm, the image density will be insufficient. If the thickness exceeds 2.0 μm, the thermal sensitivity tends to decrease, and good image formation tends to be hindered. The heat transferable protective layer of the present invention comprises a support and a protective layer and an adhesive layer sequentially laminated on the support. At least one resin selected from acrylic resin, cellulose resin and polyvinyl butyral resin is used as the main component of the protective layer, and the adhesive layer contains wax containing ethylene vinyl acetate copolymer and / or ethylene ethyl acrylate copolymer as the main component. To do. As the wax, the waxes mentioned in the color inks can be used. The content of the wax is preferably 30 to 100 parts by weight with respect to 100 parts by weight of the resin component. When the content of the wax is less than the above range, the overlaying property on the color ink containing wax as a main component tends to decrease, and when the content of the wax exceeds the above range, the adhesion with the protective layer deteriorates, A good protective layer cannot be formed. The melting temperature of the wax used in the adhesive layer is usually 45 to 70 ° C.
In addition, by lowering the melting temperature of the wax used in the adhesive layer below the melting temperature of the color ink layer for image formation, the transfer sensitivity of the protective layer is higher than that of the color ink, and the heat of transfer of the protective layer causes the color image to collapse. Can be made less likely to occur. In addition to this, a filler such as silica, silicone oil, a fluorosurfactant, or other lubricant may be added to the adhesive layer in order to prevent blocking and the like. Furthermore, by adding a silicone-modified resin to the protective layer, the peeling property of the protective layer during thermal transfer is improved, and the effect of scratch resistance by the protective layer is improved. Examples of the silicone-modified resin include acrylic resins, polyester resins, urethane resins, and polyvinyl alcohol resins. The mixing ratio is preferably in the range of 5 to 40 parts by weight with respect to 100 parts by weight of the main component resin. If it is less than this range, the above effect is hard to occur, and if it exceeds this range, the adhesiveness to the adhesive layer is deteriorated, and delamination occurs at the contact surface between the protective layer and the adhesive layer during thermal transfer.

The coating thickness of the protective layer is 0.5 to 3.
Suitably in the range of 0 μm, below 0.5 μm
A good film cannot be formed and scratch resistance is poor. When it exceeds 3.0 μm, the film strength of the protective layer is too strong and the sharpness at the time of thermal transfer is deteriorated. Good transfer cannot be achieved with a battery-driven mobile printer.

The thickness of the adhesive layer is 0.3 to 2.0 μm.
The range of m is appropriate. If it is less than 0.3 μm, good adhesion cannot be obtained, and if it exceeds 2.0 μm, the sensitivity is lowered.

[0013]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The present invention is not limited to the embodiments. As the support, a polyester film having a thickness of 3.5 μm in which a 0.2 μm-thick heat-resistant layer of silicone resin was applied to the surface opposite to the ink application surface was used. A yellow ink layer, a magenta ink layer, a cyan ink layer, and a heat transferable protective layer were coated and provided on the same support in a frame order to obtain a heat melt transfer recording medium. The coating length in the printing direction per screen was 120 mm. As the color ink layer, the ink formulation shown in Table 1 was applied by hot melt coating to a thickness of 1.0 μm.

[0014]

[Table 1] Table 1 Color ink formulation (parts by weight)

VA means vinyl acetate. The protective layer is
The ink formulations shown in Table 2 were applied by direct gravure coating to a solid content of 2.0 μm.

[0016]

[Table 2] Table 2 Ink formulation of protective layer (parts by weight)

As the adhesive layer, the ink formulation shown in Table 3 was applied by direct gravure coating in a solid content thickness of 1.
It was applied to 0 μm.

[0018]

Table 3 Table 3 Adhesive layer ink formulation (parts by weight)

The protective layer and the adhesive layer of the hot-melt transfer recording media of Examples 1 to 3 and Comparative Examples 1 to 3 have the structures shown in Table 4.

[0020]

[Table 4] Table 4 Structure of thermal transferable protective layer

<Printing conditions> Printer: Mobile thermal transfer full color test machine is used Image receptor: Peach coat SPU-160XEW (manufactured by Nisshinbo Industries) Image size: Card size (54 mm x 85 mm) <Evaluation method> Image quality A full color photographic image is printed with the above printer, and a thermal transfer protective layer is overprinted. The degree of image disturbance was visually determined according to the criteria shown in Table 5.

[0022]

[Table 5] Table 5

Glossiness The gloss after overprinting was measured at 60 ° gloss with a gloss meter. As the glossiness measuring device, GM-260 manufactured by Murakami Color Co., Ltd. was used. Weighted 49.000 on color image after scratch-resistant overprint
Scratch resistance test in which cotton cloth is reciprocated 100 times at Pa (testing machine: A.A.T.C.C. clock meter model CM
-1, manufactured by Atlas Electric Device Co., Ltd.) was performed, and the degree of damage of the color image was visually observed, and the image protection effect of each thermal transferable protective layer was compared and evaluated based on the criteria in Table 6.

[0024]

[Table 6] Table 6

Table 7 shows the evaluation results of.

[0026]

[Table 7] Table 7 Evaluation results

In Comparative Example 3, the transfer of the thermal transferable protective layer was defective.

As shown in Table 7, in the examples, the image quality, glossiness, and scratch resistance were all good in practical use. On the other hand, in the comparative example, the image quality was not satisfactory in practical use.

[0029]

The heat-melt transfer recording medium having the protective layer of the present invention forms an image on a mobile printer that thermally transfers at low energy, and then overprints the thermal transferable protective layer to obtain good image quality and gloss. It was possible to obtain scratch resistance.

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Claims (2)

[Claims] 1. A thermal melt transfer recording in which a color ink layer containing wax as a main component and a thermal transferable protective layer in which a protective layer and an adhesive layer are laminated in this order on a support are provided in a frame order. In the medium, the main component resin of the protective layer is a resin selected from at least one selected from acrylic resin, cellulose resin and polyvinyl butyral resin, and the adhesive layer is ethylene vinyl acetate copolymer and / or ethylene ethyl acrylate copolymer. A heat-melt transfer recording medium containing, as a main component, a wax. 2. A thermal melt transfer recording medium according to claim 1, wherein the protective layer contains a silicone-modified resin.