JP3177506B2 - Thermal transfer recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording medium used for a thermal transfer recording apparatus such as a printer, a bar code, a facsimile, and the like.

[0002]

2. Description of the Related Art Conventionally, there has been known a thermal transfer medium for forming a printed image having good print quality even on paper having poor surface smoothness (hereinafter referred to as rough paper). For example, a thermal transfer recording medium using a cross-linking transferable ink layer (referred to as a high-melt-viscosity ink layer that adheres only to the convex portion of rough paper and does not adhere to the concave portion and is transferred like a bridge). Is an example. However, since this type of thermal transfer recording medium uses a high melt viscosity ink layer, the shearing force of the ink is increased, and the print breakability is poor. In addition, a phenomenon such as sticking of a ribbon to a transfer receiving paper also occurs, which causes a transfer failure. On the other hand, a thermal transfer recording medium using a permeable ink layer (referred to as a low melt viscosity ink layer that allows ink to flow into concave portions of rough paper) is also an example. In this type of thermal transfer recording medium, the absolute amount of ink is inevitably increased in order to obtain concealment properties, which not only leads to an increase in cost, but also causes problems such as dropping of ink from the base material. In addition, color reproducibility is poor because the amount of ink transferred to the convex portion of the rough paper is small.

[0003]

SUMMARY OF THE INVENTION In view of the foregoing, the present invention can form a clear printed image with good ink breakage and good transferability while maintaining good cross-linking transferability. It is an object to provide a thermal transfer recording medium.

[0004]

The invention according to claim 1 is
Release layer on a support, the colored ink layer, in order provided comprising a thermal transfer recording medium an adhesive layer, the colored ink layer in the layer thickness is 0.05 to 0.5 [mu] m, polyvinyl butyral or
Or binder comprising ethylene-vinyl acetate copolymer
And made from the pigment, a layer which does not melt at the time of thermal transfer, containing a pigment at least 50 wt%, the adhesive layer contains a resin 50% by weight or more, the resin is a styrene - isoprene - Suchirenbu
Rock copolymer, styrene-butadiene-styrene bromide
Block copolymer, styrene-ethylene-butylene-styrene
Styrene selected from the group consisting of ren block copolymers
Block copolymer and rosin, styrene, terpene
Phenol, coumarone indene
A thermal transfer recording medium comprising a selected tackifier resin .

The invention according to claim 2 is characterized in that the content of the pigment in the colored ink layer is 80% by weight or more and the average particle diameter of the pigment is 0.5 μm or less. The present invention relates to a thermal transfer recording medium.

According to a third aspect of the present invention, the thickness of the adhesive layer is 0.05 to 0.7 μm.
Or a thermal transfer recording medium according to 2.

According to a fourth aspect of the present invention, the total layer thickness of the release layer, the colored ink layer, and the adhesive layer is 1.5 μm or less. The present invention relates to a thermal transfer recording medium.

[0008]

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer recording medium of the present invention has a structure in which a release layer, a colored ink layer and an adhesive layer are provided on a support in this order. Hereinafter, the release layer, the colored ink layer, and the adhesive layer may be collectively referred to as a transfer layer.

Examples of the support usable in the present invention include polyester films such as polyethylene terephthalate film and polyethylene naphthalate film, polycarbonate films, polyamide films, aramid films, and other films generally used as a support film for this type of ink ribbon. Various types of plastic films used can be used. Also, high-density thin paper such as condenser paper may be used. The thickness of the support is preferably about 1 to 10 μm, particularly preferably about 2 to 7 μm, from the viewpoint of good heat conduction and maintaining strength.

When the plastic film is used as a support, the surface opposite to the transfer layer (the surface in contact with the thermal head) is a silicone resin, a fluorine resin, a nitrocellulose resin, A conventionally known stick prevention layer made of various heat resistant resins such as silicone-modified acrylic resin, or a mixture of these heat resistant resins with a lubricant may be provided.

The release layer is a heat-meltable layer mainly composed of waxes. Examples of the waxes include natural waxes such as plant waxes such as candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil, animal waxes such as beeswax, lanolin, and whale wax, montan wax, ozokerite, and ceresin. Petroleum wax such as mineral wax, paraffin wax, microcrystalline wax, petrolatum, etc.
Fischer-Tropsch wax as synthetic wax,
Synthetic hydrocarbon waxes such as polyethylene wax,
Montan wax derivatives, paraffin wax derivatives,
Modified waxes such as microcrystalline wax derivatives, hydrogenated waxes such as hardened castor oil, hydrogenated castor oil derivatives, fatty acids such as lauric acid, palmitic acid, myristic acid, stearic acid, 1,2-hydroxystearic acid, and fatty acid amides Species or two or more can be used. If necessary, acrylic, styrene, rosin, ester, vinyl, acetal, polyamide, rubber, cellulose and other resins, calcium carbonate, precipitated barium sulfate, inorganic pigments such as silicon dioxide, Other additives may be blended.

The colored ink layer is an ink layer containing 50% by weight or more of a pigment and not melting at the time of thermal transfer, and the binder is polyvinyl butyral or ethylene-vinegar.
It consists of an acid vinyl copolymer . Here, the term “not melted during thermal transfer” is a concept including a case where neither melting nor softening is performed, and a case where softening is performed but not melting. As the pigment, various inorganic and organic pigments can be used. Inorganic pigments, azo lakes, hanzas, benzimidazolones, monoazos, diallylides, pyrazolones, condensed azos, phthalocyanines, quinacridones, perylenes, perinones, dioxazines, anthraquinones,
Organic pigments such as isoindolinone type are exemplified . In is al <br/> added curing agent polyisocyanate such as color ink layer may be cured resin. In this case, those having a reactive group of the hydroxyl group or the like as a resin. If necessary, waxes, plasticizers, surfactants, and the like exemplified for the release layer can be appropriately added.

In the present invention, the content of the pigment in the colored ink layer is at least 50% by weight, preferably at least 80% by weight. Thereby, it does not substantially melt during thermal transfer. Further, in the present invention, the thickness of the colored ink layer is set to 0.05 to 0.5 μm. If the content of the pigment in the colored ink layer is smaller than the above range, or if the thickness of the colored ink layer is larger than the above range, the cutability of the ink layer is deteriorated. When the thickness of the colored ink layer is smaller than the above range, the image density becomes insufficient. Although the content of the pigment in the colored ink layer may be 100% by weight (that is, no binder is present), the content of the pigment is usually set to 95% by weight or less in order to secure good cross-linking transferability. Is preferably 5% by weight or more. When the content of the pigment in the colored ink layer is 80% by weight or more, an ink layer having a higher concentration in a thin film can be obtained. In this case,
It is preferable to use pigments having an average particle diameter of 0.5 μm or less.

[0015] The adhesive layer of the tree fat 50 wt% or more containing Yes
And, the resin is a styrene - isoprene - styrene block copolymer (SIS), styrene - butadiene - styrene block copolymer (SBS), styrene - ethylene - I from styrene block copolymer (SEBS) - butylene
That styrenic block copolymer and rosin selected from the group, Toka styrene, terpene, phenol, tackifier resin selected from the group consisting of coumarone-indene-based
Become . If necessary, waxes, inorganic pigments, plasticizers, coloring pigments, surfactants and the like exemplified for the release layer may be added. The thickness of the adhesive layer is preferably in the range of 0.05 to 0.7 [mu] m, because if the thickness is too large, the cuttability of the ink is inferior and transfer failure is caused.

In the thermal transfer recording medium of the present invention, the layer thickness of the transfer layer (that is, the layer in which the release layer, the colored ink layer and the adhesive layer are laminated) is set to 1.5 μm or less in terms of print breakability. Is preferred.

The thermal transfer recording medium of the present invention comprises a single color recording layer having a single color ink layer on a support, a yellow, magenta, cyan ink layer and, if necessary, a black ink layer. Or on a separate support for color recording.

The thermal transfer recording medium of the present invention has a poor heat sensitivity, in which the colored ink layer does not melt during thermal transfer.
When recording on rough paper with a thermal transfer printer using the thermal transfer recording medium of the present invention, the colored ink layer does not melt due to the heat from the thermal head, so the ink does not adhere to the concave portions of the rough paper and adheres only to the convex portions. Cross-linking transfer becomes possible, and a printed matter having no voids (voids) is obtained. Further, the thermal transfer recording medium of the present invention has a very small thickness, and the pigmented ink layer contains 50% by weight or more of pigment, so that the ink has a small shearing force and good cuttability,
Excellent sharpness of prints. Further, since the colored ink layer is very thin, a printed matter excellent in color developability can be obtained.

Further, when the content of the pigment in the colored ink layer is 8
In a preferred embodiment in which the content of the pigment is 0% by weight or more and the average particle size of the pigment is 0.5 μm or less, a printed matter excellent in sharpness and coloring is obtained.

When color printing is performed using the thermal transfer recording medium of the present invention, the colored ink layer previously transferred as the primary color is melted by the heat of the thermal head generated at the time of printing the secondary color and thereafter. Therefore, good color reproduction can be achieved without mixing of the colored inks.

[0021]

Next, the present invention will be described in detail with reference to examples.

Examples 1 to 2 and Comparative Examples 1 to 4 A 3.5 μm thick polyethylene terephthalate film having a 0.1 μm thick modified silicone resin stick prevention layer formed on one surface was formed on the other surface. A release layer ink having a thickness of 0.5 μm was formed by hot-melt coating the release layer ink shown in Table 1 and a colored ink shown in Table 1 was applied thereon using a Mayer bar, and dried at 60 ° C. To form a colored ink layer having the thickness shown in Table 1, and then apply the adhesive ink shown in Table 1 thereon using a Mayer bar,
Dried at 60 ° C. to form an adhesive layer having a thickness shown in Table 1,
A thermal transfer recording medium was obtained.

Using the thermal transfer recording medium obtained above, printing is performed with a line-type thermal transfer printer, and the print density (reflection OD value) of the obtained print is measured, and print quality (void, sharpness), ribbon Was evaluated for sticking. Xerox Corporation 4200 paper (Beck smoothness: 25 seconds) was used as the receiving paper. Table 2 shows the results.

<Printing conditions> Dot density: 300 dots / inch Printing speed: 100 mm / sec Printing energy: 40 mJ / mm ² Printing pattern: 1 dot, ruled line, solid pattern

<Reflection OD value> Reflection densitometer R manufactured by Macbeth
It was measured by D918.

<Void> Evaluation was made according to the following criteria. ：: No void in printing. Δ: There are some voids in the print. ×: There are many voids in printing.

<Sharpness> The sharpness was evaluated according to the following criteria. A: A very sharp print is obtained. ：: A sharp print is obtained. Δ: The print sharpness was somewhat poor. X: Poor print sharpness.

<Stuck> ○: The ribbon can be transferred without sticking to the transfer paper. ×: The ribbon is stuck to the receiving paper, and transfer failure occurs.

[0029]

[Table 1]

[0030]

[Table 2]

Example 3 In Example 1, yellow pigment (CI.P.Y.14), magenta pigment (CI.P.R.57: 1), and cyan pigment (C.I.) were used instead of carbon black in the colored ink layer.
I. P. B. 15: 4), except that a ribbon of yellow ink, a ribbon of magenta ink, and a ribbon of cyan ink were obtained in the same manner. Yellow under these printing conditions using these ribbons,
Magenta and cyan were superposed and printed to obtain a multicolor print. Observation of the printed matter by visual inspection revealed that there was no color unevenness due to ink mixing or transfer failure due to ink repelling, and the desired color reproduction by the subtractive color mixing method was possible.

[0032]

According to the thermal transfer recording medium of the present invention, it is possible to form a clear printed image with good cut of ink and good transferability while maintaining good cross-linking transferability. In addition, when color printing is performed, mixing between the colored ink layers does not occur, and good color reproduction can be performed.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masamichi Yamano 5-14-14 Moundoshima, Nishiyodogawa-ku, Osaka-shi, Osaka Fujikopian Corporation Technical Center (72) Inventor Shinichiro Masanobu 5-chome Migoshima, Nishiyodogawa-ku, Osaka, Osaka No. 4-14 Fujikopian Corporation Technical Center (56) References JP-A-10-138648 (JP, A) JP-A-2-219696 (JP, A) JP-A-2-130192 (JP, A) JP-A-3-183594 (JP, A) JP-A-62-90287 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (4)

(57) [Claims] 1. A release layer on the support, the colored ink layer, in order provided comprising a thermal transfer recording medium an adhesive layer, the colored ink layer layer thickness is in the 0.05 to 0.5 [mu] m, polyvinyl
From rubutyral or ethylene-vinyl acetate copolymer
The adhesive layer contains 50% by weight or more of a resin and contains 50% by weight or more of a pigment.
-Styrene block copolymer, styrene-butadiene
-Styrene block copolymer, styrene-ethylene-
Selected from the group consisting of butylene-styrene block copolymers
Styrenic block copolymer and rosin-based, styrene
Based, terpene based, phenol based, coumarone indene based
A thermal transfer recording medium comprising a tackifier resin selected from the group consisting of: 2. The pigment ink content in the colored ink layer is 80% by weight or more, and the average particle diameter of the pigment is 0.5 μm.
2. The thermal transfer recording medium according to claim 1, wherein: 3. The adhesive layer has a thickness of 0.05 to 0.7 μm.
The thermal transfer recording medium according to claim 1, wherein: 4. The thermal transfer recording medium according to claim 1, wherein the total thickness of the release layer, the colored ink layer, and the adhesive layer is 1.5 μm or less.