JPH11157219A - Thermal transfer ink ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer ink ribbon preventing effectively the generation of line voids while keeping heat resistance and lubrication properties of a lubricating layer in a good manner and not generating a defective image. SOLUTION: A thermal transfer ribbon is provided with a thermal transfer ink layer formed on one face of a substrate and a lubricating layer on the other face, and the thickness of the lubricating layer is 0.005-0.02 μm. At least a binder and wax are contained in the lubricating layer, and the melting point of wax is preferably 70-100 deg.C. It is required that the thickness of the lubricating layer is 0.005-0.02 μm, preferably 0.007-0.015 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer ink ribbon for forming a color image by thermally transferring a thermal transfer ink layer onto an image receiving sheet material.

[0002]

2. Description of the Related Art As a thermal transfer recording system for forming a color image by using a printer having a thermal head, a sublimation dye transfer system and a heat melting type transfer system are conventionally known.

In the sublimation type dye transfer system, a thermal transfer ink ribbon having a thermal transfer ink layer containing a sublimation type dye and a binder is provided on a support, and the thermal transfer ink ribbon is superposed on an image receiving sheet. In this method, an image is formed on the image receiving sheet by applying heat to the image by a thermal head to sublimate the sublimation dye and transfer it to the image receiving sheet. In the case of the sublimation dye transfer method, a color image can be formed by using a color thermal transfer ink ribbon having yellow, magenta, and cyan thermal transfer ink layers.

[0004] On the other hand, in the heat-melt transfer method, a heat-transfer ink ribbon provided with a heat-meltable transfer layer containing a coloring material such as a pigment or a dye and a binder such as a wax on a support is superimposed on an image receiving sheet. An image is formed on the image receiving sheet by applying heat imagewise from the back side of the support of the thermal transfer ink ribbon by the thermal head to melt the heat fusible transfer layer and fuse it on the image receiving sheet. It is a method to do.

As a support for these thermal transfer ink ribbons, a support made of polyethylene terephthalate or the like is used. From the viewpoint of improving the sliding between the thermal head and the support during printing and improving the image quality. For this reason, it is common practice to provide a lubricating layer having good heat resistance and lubricity on the support. However,
When printing is performed using the thermal transfer ink ribbon having the lubricating layer by the thermal head, an image defect called a line void may occur due to a foreign substance sandwiched between the support and the thermal head. There is a big problem in quality.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a thermal transfer ink ribbon that effectively prevents the generation of line voids while maintaining good heat resistance and smoothness of a slipping layer, and does not cause image defects. I do.

[0007]

The present inventors have earnestly studied and obtained the following findings. That is, in a thermal transfer ink layer having a lubricating layer on a support, the degree of heat resistance and lubricating property of the lubricating layer depends on the thickness of the lubricating layer. It is a finding that the lubrication layer is caused by a peeled material. Further, it is a finding that the slipperiness between the thermal head and the support depends on the melting point of the wax contained in the slip layer.

According to the present invention, based on the above findings by the present inventors, means for solving the above problems are as follows. That is, <1> having a thermal transfer ink layer on one surface of the support,
It has a lubricating layer on the other surface, and the lubricating layer has a thickness of 0.
005 to 0.02 μm. <2> The lubricating layer contains at least a binder and a wax, and the melting point of the wax is 70 to 100 ° C.
1> The thermal transfer ink ribbon according to <1>.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the thermal transfer ink ribbon of the present invention will be described in detail. The thermal transfer ink ribbon of the present invention has a thermal transfer ink layer on one side of a support and a lubricating layer on the other side.

-Slip layer- The thickness of the slip layer is 0.005 to 0.02 µm.
0.007 to 0.015 μm
It is preferred that The thickness of the slipping layer is 0.00
When the thickness is less than 5 μm, the heat resistance and the slipperiness of the lubricating layer deteriorate, and the lubricating layer cannot function as a lubricating layer. When the thickness exceeds 0.02 μm, the support and the thermal head etc. In between, the peeled material of the lubricating layer is caught and line voids are generated. On the other hand, when the thickness of the lubricating layer is within the above numerical range, such a case does not occur, and the object of the present invention can be effectively achieved.

The thickness of the lubricating layer can be measured, for example, by using a stylus type film thickness meter (ALPHA STEP500, manufactured by Tencor Instruments Japan).

As for the material of the slipping layer, the object of the present invention of maintaining good heat resistance and slipping property of the slipping layer and preventing generation of line voids can be effectively achieved. There is no particular limitation as long as it is not particularly limited, and it can be appropriately selected from known materials according to the purpose. However, it is preferable that the lubricating layer contains at least a binder and a wax.

The binder is not particularly limited and may be appropriately selected from known materials according to the purpose. Examples thereof include polyolefin, polyester resin, and acrylic resin.

The melting point of the wax is 70 to 10
0 ° C is preferred, and 90 to 100 ° C is more preferred. When the melting point of the wax is less than 70 ° C., when heat is applied imagewise to the surface of the support having a slipping layer with a thermal head or the like, blocking may occur. In some cases, the slipperiness of the slippery layer deteriorates. The melting point of the wax can be measured, for example, by differential scanning calorimetry (DSC).

The method of forming the above-mentioned lubricating layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the lubricating layer may be prepared by dissolving the above components in a known solvent. A method in which a coating solution is applied on a support and dried is used.

The content of the wax in the slipping layer coating solution is preferably 1 to 50 parts by weight, and 3 to 2 parts by weight.
5 parts by weight is more preferred. When the content of the wax is 5
If the amount is more than 0 parts by weight, the head may be stained at the time of printing. If the amount is less than 1 part by weight, the slipperiness may be reduced and sticking may occur. The lubricating layer in the present invention,
Any of a single layer structure and a laminated structure may be used.

-Support-Examples of the material of the support include polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), polycarbonate, polypropylene, polyvinyl chloride, and the like. Among them, polyester is preferable, and polyethylene terephthalate is more preferable.

The structure of the support is not particularly limited, and may be a foamed sheet or a laminate of films of different materials. Note that, for example, the back surface of the support may be subjected to a release treatment or the like.

The average thickness of the support is 2 to 8 μm.
m is preferable and 3 to 6 μm is more preferable. If the average thickness is less than 2 μm, the transportability of the thermal transfer ink ribbon may deteriorate, and if it exceeds 8 μm, the recording sensitivity of the thermal transfer ink ribbon may decrease.

-Thermal transfer ink layer-The thermal transfer ink layer contains, for example, a pigment, a binder, a release agent, a softener, and the like.

The pigment is not particularly limited and may be appropriately selected from known pigments.
Pigments such as carbon black, azo type, phthalocyanine type, quinacridone type, thioindigo type, anthraquinone type and isoindoline type are exemplified. These may be used alone or in combination of two or more. In the present invention, a known dye may be further added for adjusting the hue.

The binder has a softening point of 40 to 40.
An amorphous organic high molecular polymer at 150 ° C. is preferably used. The softening point of the amorphous organic high molecular polymer is 40 ° C.
If it is less than 150, the adhesion resistance of the thermal transfer ink layer is inferior, and
If the temperature exceeds ℃, the thermal recording sensitivity of the thermal transfer ink layer may be inferior.

Examples of the amorphous organic polymer having a softening point of 40 ° C. to 150 ° C. include butyral resin, polyamide resin, polyethylene imine resin, sulfonamide resin, polyester polyol resin, petroleum resin, styrene, vinyl Styrene such as toluene, α-methylstyrene, 2-methylstyrene, chlorostyrene, vinylbenzoic acid, sodium vinylbenzenesulfonate, aminostyrene and derivatives thereof, homopolymers and copolymers of substituted products, methyl methacrylate, ethyl methacrylate , Butyl methacrylate, methacrylic acid esters such as hydroxyethyl methacrylate and methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, α
-Acrylic esters such as ethylhexyl acrylate and dienes such as acrylic acid, butadiene and isoprene, acrylonitrile, vinyl ethers, maleic acid and maleic esters, maleic anhydride, cinnamic acid, vinyl chloride and vinyl acetate. Monomers may be used alone or copolymers with other monomers.
These may be used alone or in combination of two or more. Among them, from the viewpoint of dispersibility,
Butyral resins and styrene / maleic acid half ester resins are particularly preferred.

The release agent and the softening agent are added to the thermal transfer ink layer from the viewpoint of improving the releasability of the thermal transfer ink layer from the support and the thermal sensitivity during thermal printing. The content of the release agent or the softener in the thermal transfer ink layer is about 1 to 20% by weight based on the total amount of the thermal transfer ink layer.

Specific examples of the release agent and the softener include higher fatty acids such as palmitic acid and stearic acid, metal salts of fatty acids such as zinc stearate, fatty acid esters or partially saponified products thereof, and fatty acid amides. Fatty acid derivatives, higher alcohols, ether derivatives of polyhydric alcohols, waxes such as paraffin wax, carnauba wax, montan wax, beeswax, wood wax, candelilla wax, having a viscosity average molecular weight of about 1,000 to about 10 Polyolefins such as low molecular weight polyethylene, polypropylene and polybutylene of about 2,000, or olefins, α-olefins and maleic anhydride,
Acrylic acid, organic acids such as methacrylic acid, low molecular weight copolymers with vinyl acetate, etc., low molecular weight oxidized polyolefins, halogenated polyolefins, lauryl methacrylate,
Methacrylates having long alkyl side chains such as stearyl methacrylate, acrylates or acrylates having a perfluoro group, methacrylates alone or copolymers with vinyl monomers such as styrene, polydimethyl Siloxane, low molecular weight silicone resins such as polydiphenylsiloxane and silicone-modified organic substances, and further, ammonium salts having long-chain aliphatic groups, cationic surfactants such as pyridinium salts,
Alternatively, similarly, an anion having a long-chain aliphatic group, a nonionic surfactant, a perfluoro-based surfactant and the like can be mentioned. These may be used alone or in combination of two or more.

The optical density of the thermal transfer ink layer is as follows:
When thermally transferred onto a white support, the higher the reflection density, the better. For example, the reflection density is preferably 1.0 or more.

The thickness of the thermal transfer ink layer is set to 0.1.
2 to 1.0 μm is preferred. When the thickness is more than 1.0 μm, in the tone reproducibility based on the area tone alone, the shadow portion is easily crushed or the highlight portion is liable to fly, resulting in poor tone reproducibility. Yes, 0.
If it is less than 2 μm, it tends to be difficult to obtain a predetermined concentration.

The thermal transfer ink layer preferably contains the pigment in an amount of 30 to 70 parts by weight.
It is preferred that it be contained in parts by weight. If the amount of the pigment added to the thermal transfer ink layer is out of the numerical range, it is difficult to obtain a predetermined concentration. As for the particle size of the pigment, it is preferable that 70% or more of the pigment has a particle size of 1.0 μm or less. When the particle size of the pigment is large, the transparency of the overlapping portion of each color during color reproduction is impaired, and it becomes difficult to maintain the relationship between the thickness and the density of the thermal transfer ink layer in a good range. .

For dispersing the pigment in the binder (amorphous organic high-molecular polymer), various dispersion methods used in the field of coatings can be applied. For example, a solvent appropriately selected is added to the pigment. A method of adding and dispersing using a ball mill or the like can be employed.

The thermal transfer ink layer is prepared, for example, by dissolving each of the above-mentioned components in an appropriately selected known solvent to prepare a thermal transfer ink layer coating liquid, and applying the thermal transfer ink layer coating liquid on a support. And then dried.

The main components of the thermal transfer ink layer are the pigment and the binder (amorphous organic high polymer),
When the pigment ratio is higher than that of the conventional wax-melted thermal transfer ink layer, the viscosity at the time of thermal transfer is 10 ² to 10 ³ cp as compared with the wax-melted thermal transfer ink layer.
Since it does not decrease as in s and is higher than at least 10 ⁴ cps at 150 ° C., a thermal transfer ink ribbon of a thin film peeling development type can be obtained.

In the case of the thermal transfer ink ribbon of the thin film peeling development type, in addition to the effect of thinning the thermal transfer ink layer, while maintaining high resolution, a wide gradation from the shadow portion to the highlight portion can be obtained. Reproduction can be performed, edge sharpness can be improved, and 100% image transfer can be performed, and uniformity of density between small characters such as four points and solid portions can be realized.

The image receiving sheet used when forming an image by thermal transfer in combination with the thermal transfer ink ribbon of the present invention is not particularly limited, and a known image receiving sheet can be used. Soft synthetic paper, U
S44826225, US47666053, US49
The image receiving sheet described in each specification of No. 33258 is preferably exemplified.

The support in these image receiving sheets includes, for example, paper, plastic films such as polyester films, polycarbonate films, polypropylene films, and polyvinyl chloride films.

When the image receiving sheet is used for proofing, an image is formed on the same paper as the actual printing paper.
The transferred image formed on the plastic film may be retransferred to the printing paper to form an image.

[0036]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1 and Comparative Examples 1 and 2) A support made of polyethylene terephthalate (4.5 μm thick) was provided with a slip layer on one surface and a thermal transfer ink layer on the other surface. A thermal transfer ink ribbon was produced.
The lubricating layer is made of a polyester resin (100 parts by weight) and carnauba wax (2 parts) using methyl ethyl ketone as a solvent.
0 parts by weight), and the coating liquid for a slipping layer was applied to the support so as to have a thickness shown in Table 1 and dried. . The thermal transfer ink layer,
Butyral resin (manufactured by Sekisui Chemical Co., Ltd., S-LEC FD) using 110.4 g of n-propyl alcohol as a solvent
11. P-1, softening point 70 ° C., average degree of polymerization 300 or less)
0 g and a cyan pigment (CI Pigment Blue 15:
4) A coating solution for thermal transfer ink containing 12 g and 0.8 g of a dispersing aid (Solsperse S-2000, manufactured by ICI Japan Co., Ltd.) was prepared. The coating was applied to the support so as to have a thickness of 3 μm and dried.

Using the obtained thermal transfer ink ribbon, an image forming apparatus (First Photo, manufactured by Fuji Photo Film Co., Ltd.)
Printing was performed using Proof Type M), and generation of line voids due to peeling of the slipping layer and slippage with the thermal head were evaluated. The following describes these evaluation methods.

<Generation of Line Voids> The generation of line voids was evaluated by observing white streaks formed on the print sample. <Slip with Thermal Head> Slip with the thermal head was evaluated by observing the presence or absence of sticking in the print sample.

[0040]

[Table 1]

Example 2 and Comparative Examples 3 and 4 In Example 1, except that the melting point of carnauba wax in the coating liquid for a lubricating layer was changed as shown in Table 2, the same as in Example 1 was used. A thermal transfer ink ribbon was produced in the same manner, and the obtained thermal transfer ink ribbon was evaluated for slippage with a thermal head in the same manner as in Example 1, and further evaluated for adhesion failure of the slippery layer described below. <Adhesion Failure> Adhesion failure was evaluated by microscopic observation of the shape of the back surface on the lubricating layer side and the ink surface on the thermal transfer ink layer side of the thermal transfer ink ribbon.

[0042]

[Table 2]

[0043]

According to the present invention, the above-mentioned conventional problems can be solved. Further, according to the present invention, it is possible to provide a thermal transfer ink ribbon that effectively prevents the generation of line voids and does not cause image defects while maintaining the heat resistance and the slipperiness of the slippery layer well. .

Claims (2)

[Claims] 1. A support having a thermal transfer ink layer on one surface and a lubricating layer on the other surface, wherein the lubricating layer has a thickness of 0.005 to 0.02 μm. A thermal transfer ink ribbon, characterized in that: 2. The thermal transfer ink ribbon according to claim 1, wherein the lubricating layer contains at least a binder and a wax, and the melting point of the wax is 70 to 100 ° C.