JP4224564B2 - Thermal transfer recording medium - Google Patents

Description

【００３４】
【発明の効果】
本発明の熱転写記録媒体により、バリアブル性能を含めた階調再現性、ドット再現性および鮮明性に優れた画像を形成することができる。
【図面の簡単な説明】
【図１】本発明の熱転写記録媒体の１実施例を示す概略断面図である。
【符号の説明】
１ 基材
２ 転写制御層
３ 熱転写インク層
４ 無機層状化合物の扁平な薄片[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal transfer recording medium suitable for image formation excellent in gradation reproducibility including variable performance, dot reproducibility and sharpness in a thermal transfer printer.
[0002]
[Prior art]
In an ink-laminated thermal transfer recording medium in which a transfer control layer is provided on a base material and a thermal transfer ink layer is provided thereon, the layer provided on the transfer control layer exceeds the transfer control layer during thermal transfer and is on the base material side. Also has the effect of developing adhesiveness. In order to prevent the influence, the transfer control layer needs to have a certain thickness or more, specifically about 1.0 μm or more, and as a whole, it cannot be thinned, the dot shape becomes unstable, and a smooth gradation is produced. Problems such as inability to obtain occurred.
[0003]
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned problems of the prior art and to provide a thermal transfer recording medium capable of obtaining an image recording excellent in gradation reproducibility, dot reproducibility and image sharpness when used in a thermal transfer printer. To do.
[0004]
[Means for Solving the Problems]
The invention according to claim 1, on [Claim 1] substrate, at least, the transfer control layer containing an inorganic layered compound, and a thermal transfer ink layer Ri Na are laminated in this order, the transfer control layer, an inorganic laminar The main component is a compound and a binder, the binder is composed of waxes and / or resins, the content of the inorganic layered compound is 1 to 300 parts by weight with respect to 100 parts by weight of the binder, and the thickness of the transfer control layer is 0 The present invention relates to a thermal transfer recording medium characterized by satisfying the following requirements: 0.04 to 0.1 μm .
A: A thermal transfer recording medium for a thermal transfer printer.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As a result of intensive studies to achieve the above object, the inventors of the present invention have obtained a dot by using a transfer control layer containing an inorganic layered compound on a substrate and a thermal transfer recording medium in which a thermal transfer ink layer is laminated in this order. The inventors have found that recording with good reproducibility, gradation reproducibility, image sharpness, etc. can be realized, and have completed the present invention. Hereinafter, the present invention will be described in detail.
[0007]
The transfer control layer of the present invention comprises an inorganic layered compound and a binder as main components, and the binder comprises waxes and / or resins. The inorganic layered compound is cleaved in the binder component, and the original regular layered structure disappears. As shown in FIG. 1, it is considered that flat thin pieces are randomly dispersed in a flat plate state in parallel with the coating surface. It is done. In FIG. 1, reference numeral 1 denotes a base material, and a transfer control layer 2 and a thermal transfer ink layer 3 are provided on the base material 1 in this order. In the transfer control layer 2, flat thin pieces 4 of the inorganic layered compound are dispersed in parallel with the application surface.
[0008]
Compared with the transfer control layer in which the inorganic layered compound is not added and the transfer control layer in which spherical or amorphous particles such as silica are dispersed, the fine dispersion in this form is less in the layer provided on the transfer control layer. The effect that the adhesive component develops adhesiveness also on the substrate side beyond the transfer control layer during thermal transfer is extremely small. In other words, the barrier performance is remarkably improved. Usually, the transfer control layer needs to have a thickness of about 1.0 μm or more, but the function can be sufficiently achieved at 0.8 μm or less. In addition, it is possible to increase the amount of components involved in adhesion to the image receiving paper in the layer provided on the transfer control layer, and it is a thin film as a whole, gradation reproducibility including variable performance, dot reproducibility and A thermal transfer recording medium excellent in sharpness can be obtained. Here, the variable performance refers to a performance capable of transferring ink in a predetermined area corresponding to so-called variable dots in which the heat generation area of the heat generating element of the thermal head is variable.
[0009]
The amount of the inorganic stratiform compound added to the transfer control layer is preferably 1 to 300 parts by weight, more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the binder. When the addition amount is less than the above range, the barrier performance is insufficient. On the other hand, when the addition amount exceeds the above range, the layer becomes brittle and the adhesion of the transfer control layer itself to the substrate tends to be insufficient. The thickness of the transfer control layer is particularly preferably 0.04 to 0.1 μm. When the thickness is less than the above range, the barrier performance is insufficient. On the other hand, when the thickness exceeds the above range, the gradation reproducibility including the variable performance during recording, the dot reproducibility, and the sharpness tend to be insufficient.
[0010]
In addition, the addition of the inorganic layered compound to the transfer control layer also reduces the charging of the thermal transfer recording medium itself due to the influence of humidity on the peelability of the transfer control layer and the development of conductivity in the state where the inorganic layered compound is dispersed. Can do.
[0011]
As the base material of the thermal transfer recording medium of the present invention, various materials conventionally used as a base material for melt transfer type and sublimation transfer type recording media can be used, but the same as the thermal transfer recording medium for a normal thermal head. Furthermore, a polyester film having a film thickness of 2.5 to 6.0 μm and a heat-resistant treatment (stick prevention layer) on the back surface is particularly preferable.
[0012]
A transfer control layer, which is a feature of the present invention, is provided on the substrate. The transfer control layer is a layer that contains an inorganic layered compound and a binder as main components and can be peeled off from the substrate during thermal transfer. The binder component includes waxes such as paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, or alcohol-soluble polyamide, water-soluble polyamide, polyacrylate, polyvinyl acetate, polyvinyl chloride, vinyl chloride and vinyl acetate. Resins having relatively weak adhesion to the substrate such as coalescence, polyvinyl butyral, polyvinyl acetal, methyl cellulose, ethyl cellulose, cellulose diacetate, cellulose triacetate, and polyvinyl alcohol can be used. Examples of inorganic layered compounds include talc, montmorillonite mineral, zirconium phosphate, teniolite, saponite, hectorite, and natural mica such as muscovite, soda mica, and phosphomica, and synthetic smectite, fluorine, silicon, etc. Swellable and non-swellable synthetic mica can be used. Two or more kinds of the binder component waxes, resins, and inorganic layered compounds can be used in combination. In addition, a surfactant or the like can be appropriately added to the transfer control layer as long as the object of the present invention is not impaired.
[0013]
A thermal transfer ink layer is provided on the transfer control layer. As the thermal transfer ink layer, a commonly used layer composed of a colorant and a binder, which is melted or softened at the time of thermal transfer and is transferred and colored on a receiver such as paper can be used.
[0014]
As binder components, waxes such as paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, polyolefin (polyethylene, polypropylene, etc.), modified polyolefin (polyethylene oxide, etc.), ethylene or propylene copolymer (ethylene / vinyl acetate copolymer) Polymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ionomer resin, ethylene / acrylic acid ester, etc.), polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinylidene chloride, polystyrene, styrene or vinyltoluene Polymer (styrene / maleic anhydride, styrene / maleic acid half ester, styrene / (meth) acrylic acid ester copolymer, etc.), poly (meth) acrylic acid ester, (meth) acrylic acid Acetal resins such as acrylate copolymers, polyvinyl butyral, polyamide resins, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyvinyl phenol, cellulose derivatives (methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, cellulose acetate, cellulose nitrate, cellulose acetate butyrate, etc.) And resins such as epoxy resin (novolak type epoxy resin, bisphenol A type epoxy resin, etc.), but are not limited thereto. These waxes and resins can be used in combination of two or more.
[0015]
A known organic or inorganic colorant can be used as the colorant.
[0016]
The contained colorant is preferably in a range where the weight ratio of the binder component to the colorant is 90:10 to 30:70. Further, from the viewpoint of improving dot reproducibility, gradation reproducibility, and image sharpness of the transferred image, the particle size of 80% or more of the particles in the particle size distribution is 0.2 μm or less, and the thickness as the thermal transfer ink layer is The thickness is preferably in the range of 0.05 to 2.0 μm and as thin as possible. In addition, the thermal transfer ink layer has a multilayer structure such as a combination of a colored ink layer and an adhesive layer separated into a colored ink layer mainly responsible for coloration and an adhesive layer mainly responsible for adhesion to a receiver such as paper. Also good.
[0017]
When the thermal transfer recording medium of the present invention is used, not only the formation of a single color image but also a full color image can be formed by performing overprinting with yellow, magenta, cyan and black colors.
[0018]
【Example】
The following examples further illustrate the present invention. However, the scope of the present invention is not limited by these. In the examples and comparative examples, “parts” all represent parts by weight, and “%” all represents weight percent.
[0019]
Example 1
(Transfer control layer 1)
Binder component: Paraffin wax / microcrystalline wax = 6/4 (weight ratio) aqueous emulsion (solid content = 20%) 10 parts Inorganic layered compound: synthetic smectite 2 parts distilled water 58.6 parts methanol 29.3 parts surfactant Agent 0.1 parts (thermal transfer ink layer)
Carbon black 54.0 parts Dispersing aid 6.0 parts Ethylene / vinyl acetate copolymer 10.0 parts Paraffin wax 40.0 parts Toluene 660.0 parts
Apply the coating solution for transfer control layer to the opposite surface of a 4.5 μm thick polyethylene terephthalate film with a 0.3 μm thick anti-stick layer on one side using a Mayer bar and dry at 60 ° C. A transfer control layer having a thickness of 0.05 μm is formed, and the thermal transfer ink layer coating liquid is applied thereon using a Mayer bar, and dried at 60 ° C. to form a thermal transfer ink layer having a coating thickness of 1.5 μm. Thus, a thermal transfer recording medium was obtained.
[0021]
Reference example 2
In Example 1, a thermal transfer recording medium was obtained in exactly the same manner as in Example 1 except that the coating thickness of the transfer control layer was changed to 0.15 μm.
[0022]
Example 3
In Example 1, a thermal transfer recording medium was obtained in exactly the same manner as in Example 1 except that the transfer control layer coating solution was changed to the following.
[0023]
(Transfer control layer 2)
Binder component: Alcohol-soluble nylon (softening point 100 ° C.) 10 parts Inorganic layered compound: Synthetic smectite 2 parts Distilled water 58.6 parts Methanol 29.3 parts Surfactant 0.1 part
Comparative Example 1
In Example 1, a thermal transfer recording medium was obtained in exactly the same manner as in Example 1 except that the transfer control layer coating solution was changed to the following.
[0025]
(Transfer control layer 3)
Binder component: Paraffin wax / microcrystalline wax = 6/4 (weight ratio) aqueous emulsion (solid content = 20%) 20 parts distilled water 50.6 parts methanol 29.3 parts Surfactant 0.1 part
Comparative Example 2
In Example 1, a thermal transfer recording medium was obtained in exactly the same manner as in Example 1 except that the transfer control layer coating solution was changed to the following.
[0027]
(Transfer control layer 4)
Binder component: Paraffin wax / microcrystalline wax = 6/4 (weight ratio) aqueous emulsion (solid content = 20%) 10 parts Granular compound: water-dispersed silica sol (solid content = 20%) 10 parts distilled water 50.6 parts Methanol 29.3 parts Surfactant 0.1 parts
Comparative Example 3
In Comparative Example 2, a thermal transfer recording medium was obtained in exactly the same manner as Comparative Example 2, except that the coating thickness of the transfer control layer was changed to 0.15 μm.
[0029]
[Evaluation]
Using each obtained thermal transfer recording medium, printing was performed with a line type thermal transfer printer (variable dot type), and dot reproducibility and gradation reproducibility were evaluated. The results are shown in Table 1.
[0030]
<Printing conditions>
Dot density: 300 dots / inch Printing speed: 250 mm / sec
Printing energy: 40.0 mJ / mm ²
Print pattern: Variable tone variable 256 gradation pattern image receptor: HR-260 (Hokuetsu Paper Co., Ltd.)
[0031]
<Dot reproducibility>
Shape: Compared with the shape of the colored dots on the thermal transfer paper, whether or not it was reproduced in the same manner was visually observed with emphasis on the halftone portion of 256 gradations, and evaluated according to the following criteria. 4 points or more are practical levels.
5 points: Reproduce exactly the same 4 points: Reproduce in the same form with a size of about ± 10% 3 points: Reproduce in the same form with a size of about ± 30% 2 points: different shapes but different shapes 1 point: different shapes and different sizes: 256 gradation highlight part (reflective OD value 0.2 or less) The uniformity of the dots in the part (1) was evaluated according to the following criteria. 4 points or more are practical levels.
5 points: all dots have no defects at all 4 points: 10 dots have about 1 defect 3 points: 10 dots have about 5 defects 2 points: almost all dots have defects 1 point: transfer There is a dot that is not [0032]
<Tone reproducibility>
The number of reproduced gradations was compared with input data of 256 gradations. Three or more points are practical levels.
5 points: Reproduction number 128 or more 4 points: Reproduction number 68 or more and less than 128 3 points: Reproduction number 32 or more and less than 68 2 points: Reproduction number 16 or more and less than 68 1 point: Reproduction number 16 or less
[Table 1]

[0034]
【The invention's effect】
With the thermal transfer recording medium of the present invention, an image excellent in gradation reproducibility including variable performance, dot reproducibility and sharpness can be formed.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing one embodiment of a thermal transfer recording medium of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material 2 Transfer control layer 3 Thermal transfer ink layer 4 Flat thin piece of inorganic layered compound

Claims (1)

On a substrate, at least, the transfer control layer containing an inorganic layered compound, and a thermal transfer ink layer Ri Na are laminated in this order, the transfer control layer, an inorganic layered compound and the binder as the main component, binder waxes and / Or resin, the content of the inorganic layered compound is 1 to 300 parts by weight with respect to 100 parts by weight of the binder, and the thickness of the transfer control layer is 0.04 to 0.1 μm, which satisfies the following requirements A thermal transfer recording medium.
A: A thermal transfer recording medium for a thermal transfer printer.

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