JPH0433894A - Thermal transfer image-receiving sheet - Google Patents

Abstract

PURPOSE:To obtain a dye thermal transfer image-receiving sheet having good printing characteristics and excellent travelling properties by laminating a conductive layer composed of cationic acrylic resin conductive agent and a color-dyeing resin layer for receiving a dye in this order on one surface of a substrate mainly composed of thermoplastic macromolecule. CONSTITUTION:When a conductive layer containing a cationic acrylic resin conductive agent as a main component is provided between a sheet substrate and a color-dyeing resin (hereinafter referred to as image-receiving layer) formed on one surface of the substrate, the possibility of static electrification and blocking by friction of the surface and rear surface of image-receiving sheets is reduced sharply. Also, the conductive layer is characterized by being provided between the substrate sheet and image-receiving layer. Because the thickness of the image-receiving layer is thinner than that of the substrate sheet, the electrification properties of the image-receiving layer are considered to be greatly influenced by the interface between the substrate and the layer. Therefore, the static electrification of the image-receiving layer is prevented when the conductive layer being a way of escape of static electricity is formed between the image-receiving layer and substrate sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dye thermal transfer image-receiving sheet for a printer that transfers a sublimable disperse dye image by heat to form a dyed image. To explain in more detail, the present invention has excellent antistatic performance, and as a result, the running properties within the printer are stable and reliable, and the images formed have high sensitivity, density, and clarity. , relates to a dye thermal transfer image-receiving sheet with excellent light resistance and heat-resistant storage stability.

[Prior Art and Problems to be Solved by the Invention] High-quality color notebook copies using thermal transfer methods In particular, dye thermal transfer printers require three colors (Y.

By heating the ink sheet having the sublimable dye layer of M and C) by continuously controlling the amount of heat of the thermal head and the heating time, the amount of transferred dye of each color is controlled,
It forms a full color density gradation image. In such a dye thermal transfer printer, the ink sheet is usually supplied in a roll, but the thermal transfer image-receiving sheet is generally supplied in sheets.

By improving the performance of thermal transfer image-receiving sheets, we have achieved high quality, high sensitivity, and
In order to obtain high-density transferred images, research is being conducted on dye-dyed layers that have a high dye transfer speed and transfer capacity, and have good storage stability.

For example, as a dye-dyeing resin, JP-A-62-244696
The publication discloses a polyester resin modified with a polyol containing a phenyl group.

However, since the ink sheets and image-receiving sheets used in dye thermal transfer printers usually have thermoplastic polymers as their main component, they are generally highly electrostatically charged, and are often molded due to static electricity generated by paper feeding and ejection movements within the printer. This causes problems such as stalls and paper jams, which impairs running performance.

A method of applying an antistatic agent treatment to either side of an ink sheet or a method of applying an antistatic agent to either side of an image receiving sheet in order to solve running problems such as static electricity and paper jams. etc. were taken.

However, when the image-receiving sheet is supplied in sheet form, treating only the ink sheet cannot prevent the image-receiving sheet from being charged, and problems such as misfeeding cannot be solved. Furthermore, since it is expected that the image-receiving sheet will be stored and used for a long period of time as a color print after receiving a color image, a stable anti-static means for a long period of time is needed to prevent dust from adhering to the image-receiving sheet. It was requested.

In order to prevent the image-receiving sheet from being electrostatically charged and eliminate running problems such as misfeed, it is effective to apply an antistatic agent to either surface of the image-receiving sheet. However, coating only on the back side was insufficient to prevent dust from accumulating due to charging during storage and use.

On the other hand, a method of coating an antistatic agent on the image-receiving layer has also been attempted. However, with the method of applying an antistatic agent over the image-receiving layer, it cannot be expected to maintain the antistatic effect over a long period of time, and there is a risk that it will have a negative effect on the dyeability of the dye, so it is not a practically effective countermeasure. It's hard to say.

In order to prevent the image-receiving layer from being charged, there is also a method of incorporating an antistatic agent into the material for forming the image-receiving layer.

When a polymeric antistatic agent is used, there is a restriction that the combination of the antistatic agent and the dye-dying resin is limited to highly compatible combinations.

In particular, the dye-staining resin is preferably hydrophobic in nature, and the antistatic agent is preferably hydrophilic in nature. Generally, when a hydrophobic resin and a hydrophilic antistatic agent are mixed, various phenomena such as phase separation, aggregation, and precipitation on the coating surface occur, making it impossible to form a stable image-receiving layer. It is easy to predict what will happen.

The relationship between polymer compatibility-phase separation and antistatic effect cannot be determined without analysis, but if both are completely dissolved, the antistatic effect will not occur, and on the other hand, if both are completely dissolved, It is predicted that even if it is separated into two, no antistatic effect will be exerted on the dye-dyeable resin. A dye-dyeable resin and an antistatic agent form a microscopic separation structure such as a certain lamella or sea-island, and partial dissolution within the structure produces an effective antistatic effect. However, it is often difficult to reproduce such a situation.

The present invention provides a dye thermal transfer image-receiving sheet that has good dye thermal transfer printing characteristics when used in a sublimation dye thermal transfer printer, has high image sensitivity and density, eliminates charging properties, and has excellent running properties. It is.

[Means and actions to solve the problem]

The dye thermal transfer image-receiving sheet of the present invention has a conductive layer made of a cationic acrylic resin conductive agent and a dye-dyeable resin layer that receives the dye on one side of a base material mainly composed of a thermoplastic polymer, in this order. By laminating, it can be used when manufacturing image sheets,
This feature prevents problems caused by static electricity during product transportation, when running inside the printer, and when printing images.

By providing a conductive layer containing a cationic acrylic resin conductive agent as a main component between a sheet-like base material and a dye-dyeable resin (hereinafter referred to as an image-receiving layer) formed on one side of the sheet-like base material, an image-receiving layer can be formed. It is possible to reduce the surface resistivity to 10 11 Ω·cm or less under the conditions of 20° C. and 50% Rh. As a result, the possibility of charging or blocking due to friction between the front and back surfaces of the image receiving sheet is greatly reduced.

The conductive layer of the present invention is characterized in that it is provided between the base sheet and the image-receiving layer. Since the thickness of the image-receiving layer is thinner than that of the base sheet, it is thought that the chargeability of the image-receiving layer is largely influenced by the interface with the base material. Therefore, a feature of the present invention is to prevent the image-receiving layer from being charged by forming a conductive layer between the image-receiving layer and the base sheet, which is an escape route for static electricity.

Some of the various plastic films used as base sheets are treated with antistatic treatment.
This was insufficient to prevent the image-receiving sheet from being charged as in the present invention.

The main component of the conductive layer is preferably a water-soluble cationic acrylic resin. Such a cationic acrylic resin has an acrylic ester or a methacrylic ester as its main component, into which a monomer unit having a cationic group is introduced by copolymerization.

The image-receiving layer of the present invention exhibits a surface resistivity of 1013 Ω·cm or more at 20°C and 50% Rh when coated alone on a base sheet, but when the image-receiving layer is laminated on a conductive layer, it exhibits a surface resistivity of 1011 Ω·cm or more. The surface resistivity is less than cm. 101
It is particularly preferable that the thickness is 00 cm or less.

In order to make the surface resistivity 1011 Ω·cm or less, a cationic acrylic resin with a solid content of 0.05 to 3.0 g/m2 is used as a conductive layer between the base sheet and the image receiving layer.
Preferably 0.2-1. It is preferable to apply the coating at Og/m2.

If the amount of coating is too large, it is not only uneconomical but also may lead to poor adhesion of the image-receiving layer. Furthermore, if the coating amount is too small, antistatic effects cannot be expected.

The conditions of 20° C. and 50% Rh are standard for office and residential environments, and are considered appropriate conditions for comparing antistatic properties.

The surface resistivity under these conditions is 10”Ω・c
When the value is higher than m, the image-receiving layer and eventually the image-receiving sheet become significantly charged, and there are concerns that problems such as running problems of the image-receiving sheet within the printer and dust adhesion to the prints may occur. Furthermore, in order to have sufficient antistatic performance at low humidity, the surface resistivity of the image-receiving layer should be 1010Ω.
It is especially preferable that it is below cm.

In the image-receiving sheet of the present invention, the image-receiving layer is made of a dye-dyeable resin material that is firmly dyed with a sublimable disperse dye transferred from an ink sheet and can stably hold a dye image, and a release agent, a white pigment, and a dye-stainable resin material. It is composed of various other additives as required. The dye-staining resin is required to have good dye receptivity, good sensitivity and acceptable density, high transfer speed and image density, little fading due to heat, and good running properties.

As the dye-dyeable resin, resins that are easily dyed with dyes, such as polyester resins, polycarbonate resins, and other disperse dye-dyeable, thermoplastic, and solvent-soluble synthetic resins, can be used alone or in combination. be able to.

It is also possible to add fluorescent dyes, dyes such as blue violet, and pigments such as white pigments to the image-receiving layer of the present invention in order to adjust the color tone as desired or necessary. Furthermore, a desired effect can be achieved by adding an ultraviolet absorber, an antioxidant, etc.

In the image-receiving layer of the present invention, a resin anti-tack agent, crosslinking agent, or slip agent is usually added to the image-receiving layer for the purpose of preventing thermal fusion with the ink sheet due to heat during printing.

The crosslinking agent improves the heat resistance of the image-receiving layer by crosslinking the dye-stainable resin, for example, polyester resin, and for polyester, polyfunctional isocyanate compounds are preferred.

As a slip agent, mold release agent, or anti-stick agent,
Silicone polymers, fatty acid ester compounds, etc. can be used. Many silicone polymers are used that have improved heat resistance through crosslinking, curing reactions, etc., and are also suitable for the image-receiving layer of the present invention. The amount added when using a silicone polymer varies depending on the heating conditions of the printer used, etc., but for boat fishing it is 0.1 to 10%.

The above white pigments, ultraviolet absorbers, anti-blocking agents, crosslinking agents,
Additives such as slip agents can be mixed with the main component resin of the image-receiving layer and applied, and ultraviolet absorbers, slip agents, etc. can be applied as a separate coating layer on or below the image-receiving layer. It may also be coated.

Generally, the thickness of the image-receiving layer is preferably 2 to 20 g/m
2, more preferably 4 to 10 g/m2.

If the image-receiving layer is too thin, there are disadvantages such as a decrease in image density and sensitivity, and a decrease in the gloss of the printed surface.

On the other hand, if it is too thick, the effect is saturated, which is not only uneconomical but also reduces the strength of the image-receiving layer.

A binder can be added to the conductive layer of the present invention, if necessary, in order to increase the adhesion with the base sheet.

As the binder, a water-soluble polymer having good compatibility or affinity with the conductive agent can be used. The amount added is preferably 50% by weight or less of the weight of the conductive layer, more preferably 20% by weight or less, which is the minimum amount added while maintaining adhesion.

The image-receiving sheet of the present invention may be provided with an antistatic slipping layer on the surface of the base sheet opposite to the image-receiving layer.

The base sheet used in the present invention includes polyester, nylon, polystyrene, polyolefin (for example, polypropylene), and a biaxially oriented multilayer structure film base (known as synthetic paper) whose main components are polyolefin resin and inorganic pigment. ), and this synthetic paper can be used with films such as polyester, with each other, or with synthetic paper and various papers, such as high-quality paper, medium-quality paper, Japanese paper, thin paper, and coated paper (
(including slightly coated paper, lightweight coated paper, art paper, etc.) can be used.

The conductive layer and the dyed layer of the sheet of the present invention can be manufactured by coating and drying using a coater such as a bar coater, gravure coater, comma coater, flade coater, air knife coater, or cake roll coater.

〔Example〕

The present invention will be explained in more detail with reference to Examples and Comparative Examples. In Examples and Comparative Examples, % and parts indicate weight % and parts by weight.

Example 1 A multilayered film (YUPO PPG 150 uncoated with conductive agent, manufactured by Tamago Oil Chemical Synthetic Paper ■) with a thickness of 150 Jim, mono- or biaxially stretched with polyolefin containing 35% inorganic NLL as the main component, was used as a support, and one side of the film was Paint with the following composition-1
was coated at a coating weight of 0.5 g/m2 in terms of solid content and dried to form a conductive layer. Also, on the other side of the support, paint-2 having the following composition
was coated at a coating weight of 1.0 g/m2 (solid content) and dried to form an antistatic slippery layer. Furthermore, a coating material 3 having the following composition was coated on the conductive layer at a solid content of 5.degree. Og/m" and dried to form a receptor layer, thereby producing an image-receiving sheet.

Paint-1 Methanol water 100 parts 200 parts Paint-2 Epoxy resin (trade name Kobocote DX-255 manufactured by Shell Chemical Co., Ltd.) 5 parts Methanol water Paint-3 100 parts 200 parts Toluene 200 parts Methyl ethyl ketone 200 parts of the obtained image-receiving sheet The surface resistivity of the image-receiving layer under the conditions of 20° C. and 50% Rh was measured using Hire high surface resistance needle manufactured by Mitsubishi Yuka.
Measured using sta MODBL 1 (T210).

The triboelectricity was measured by sensory evaluation by rubbing the front and back sides of the sheets together under the same environment.

Further, a color test pattern was printed on this image-receiving sheet using a commercially available sublimation thermal transfer color video printer (Hitachi VY-25), and the color density was evaluated using a Masbeth densitometer RD-914.

The test results are shown in Table 1.

Example 2 An image-receiving sheet was manufactured and tested in the same manner as in Example 1, except that Paint-4 having the following composition was applied at a solid content of 0.1 g/m2 and dried to form a conductive layer. .

The results are shown in Table 1.

Paint-4 Methanol 100 parts Water
20
0 parts Comparative Example 1 An image-receiving sheet was produced and tested in the same manner as in Example 1, except that the conductive layer was not provided on the support 1.

The results are shown in Table 1.

Comparative Example 2 A receiving layer of Paint-3 was first provided on Support 1, and a conductive layer of Paint-1 was provided thereon. Application of the conductive layer was difficult, resulting in noticeable imperfections such as repelling.

An image receiving sheet was manufactured and tested in the same manner as in Example 1 except for the above.

The results are shown in Table 1.

Comparative Example 3 No conductive layer was provided on the support 1, and the image-receiving layer was made of paint-5 having the following composition, and on top of the image-receiving layer, paint-6 having the following composition was applied at a solid content of 1.0 g/ An image-receiving sheet was produced in the same manner as in Example 1, except that the coating was applied in a coating amount of m2 and dried.

The test results are shown in Table 1.

Paint-5: 200 parts of toluene, 200 parts of toluene, 200 parts of methyl ethyl ketone, and 200 parts.

Claims (1)

[Claims] 1. A layer containing a cationic acrylic resin conductive agent as a main component and a layer containing a dye-staining resin as a main component are laminated in this order on one side of a base material containing a thermoplastic polymer as a main component. A dye thermal transfer image-receiving sheet featuring: