JPH1044624A - Thermal transfer printing paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer printing paper which keeps set-off suppressing properties and having good running properties. SOLUTION: A back coat layer 4 of a thermal transfer printing paper 1 contains a conductive inorg. filler with a particle size of 0.1-3μm. In a desired example mode, the material quality of a conductive inorg. filler is at least one of calcium carbonate, titanium oxide, tin oxide, zinc oxide, silicon oxide, zinc sulfide and barium sulfide to which conductive treatment is applied and the wt. ratio. of the conductive inorg. filler to the binder resin constituting the back coat layer 4 is set to 0.5-3 to provide thermal transfer printing paper keeping the strike-through suppressing properties of the back coat layer and having good running properties.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic paper for thermal transfer, and more particularly to a thermal transfer photographic paper having a dye-receiving layer formed on one side of a sheet-like substrate and a back coat layer formed on the other side. Related to photographic paper.

[0002]

2. Description of the Related Art An ink ribbon having an ink layer composed of a sublimable or heat-diffusible dye and a dye receiving layer formed on one surface of a photographic paper for thermal transfer are superimposed on each other, and the image is received in accordance with image information. There is known a sublimation type thermal transfer recording method in which a thermal head is heated and an ink ribbon is heated to transfer a dye from an ink layer to a dye receiving layer to form an image. Since the sublimation type thermal transfer recording method can form a continuous color full-color image, it is attracting attention as a method for hard-copying a video image.

FIG. 1 is a schematic sectional view of a general thermal transfer printing paper 1 used for sublimation type thermal transfer recording. As shown in FIG. 1, a dye-receiving layer 3 is formed on one surface of a sheet-like base material 2 constituting the photographic paper 1 for thermal transfer, and a back coat layer 4 is formed on the other surface. The dye receiving layer 3 is a layer that receives and holds the dye transferred from the ink ribbon during thermal transfer recording to form an image or the like, and is a thermoplastic resin that is easily dyed by a dye such as polyester, cellulose ester, polycarbonate, or polyvinyl chloride. It is formed of resin. The back coat layer 4 includes (1) a plurality of thermal transfer photographic papers 1 which are overlapped with each other in order to reduce friction of the thermal transfer photographic paper 1 in a printer for performing thermal transfer recording and improve running performance. To prevent double feed phenomenon
(3) Ink ribbon and photographic paper 1 for thermal transfer during thermal transfer recording
It is formed for the purpose of, for example, removing static electricity generated by the separation from the substrate.

On the other hand, when the thermal transfer printing paper 1 on which the image formation is completed is placed on the conventional thermal transfer printing paper 1 on which the back coat layer 4 is formed, the dye received in the dye receiving layer 3 is placed on top. There is a problem of set-off to transfer to another placed thermal transfer printing paper 1. In view of this, the present applicant has previously disclosed in Japanese Patent Application No. 6-274470, a polyvinyl acetal having an acetalization degree of 1 to 50% on the surface opposite to the dye receiving layer 3, and a dialdehyde or melamine resin. A thermal transfer photographic paper 1 having a back coat layer 4 cross-linked by the method described in Japanese Patent Application No. Hei 7-26319 is disclosed in Japanese Patent Application No. 7-26319. A thermal transfer printing paper 1 having a back coat layer 4 formed of a mixture with a resin having the same was proposed. These were all intended to improve the inhibition of the transfer of the dye from the dye receiving layer 3 in the photographic paper 1 for thermal transfer.

However, the above-described thermal transfer printing paper 1
In this case, the conductivity (static electricity elimination) of the back coat layer 4 is not always sufficient, and the running resistance of the thermal transfer printing paper 1 becomes large during continuous printing by a printer, and the thermal transfer printing paper 1 may stop abnormally. there were. To solve this,
It is effective to reduce the electric resistance by using an organic antistatic agent, but when this organic antistatic agent is used, the set-off inhibiting property is impaired. Therefore, there is a demand for a thermal transfer photographic paper 1 having good runnability while maintaining the set-off inhibiting property of the back coat layer 4 and improving the conductivity.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermal transfer printing which has good runnability without abnormally stopping a printer while improving the conductivity while maintaining the set-off inhibiting property of the back coat layer. To provide paper.

[0007]

In order to solve the above problems, in the thermal transfer printing paper of the present invention, the backing layer of the thermal transfer printing paper is made of a conductive inorganic material having a particle size of 0.1 μm or more and 3 μm or less. It is characterized by having a filler. In a preferred embodiment, the material of the conductive inorganic filler is at least one of calcium carbonate, titanium oxide, tin oxide, zinc oxide, silicon oxide, zinc sulfide, and barium sulfide that have been subjected to conductive treatment, and the back coat layer In which the weight ratio of the conductive inorganic filler to the binder resin is 0.5 or more and 3 or less.

According to the above-mentioned means, the conductive inorganic filler is uniformly dispersed without falling off from the back coat layer,
It has the effect of reducing the electrical resistance of the backcoat layer without inhibiting the adhesive strength with the sheet-like substrate. Also, there is no hindrance to set-off deterrence.

The conductive inorganic filler to be contained in the binder resin constituting the back coat layer has a particle diameter of 0.1.
Those having a thickness of 1 to 3 μm are preferred. When the particle size is 0.1 μm or less, the particles are easily aggregated and it is extremely difficult to disperse. When the particle size is 3 μm or more, the particle size is too large and may fall from the back coat layer. The amount of the conductive inorganic filler to be added is 0.5 to 3, preferably 0.7 to 2, in terms of the weight ratio to the binder resin constituting the back coat layer. If the amount of the conductive inorganic filler is 0.5 or less, the effect of eliminating static electricity is small, and if it is 3 or more, the ratio in the back coat layer is large, and the adhesion to the sheet-like substrate is small. Examples of conductive inorganic fillers include calcium carbonate, titanium oxide, tin oxide, zinc oxide,
These are particles that have been subjected to a conductive treatment such as silicon oxide, zinc sulfide, and barium sulfate.

[0010] As the binder resin constituting the back coat layer, the same resin as in the past can be used. For example, there are acrylic resins, polyester resins, polyvinyl acetal resins, and the like.In particular, polyvinyl acetal resins have a large performance of suppressing the set-off of the dye received in the dye-receiving layer to other thermal transfer printing paper. Is preferable. Further, in order to prevent fusing with the ink ribbon when printing on the back coat layer by mistake, it is desirable to cure the back coat layer with isocyanate. Further, a lubricant such as silicone oil or fatty acid or a release agent may be added to improve the lubricity.

The dye receiving layer can be formed of the same resin as in the prior art. One example is a dyeable resin such as polyester, cellulose ester, polycarbonate, and polyvinyl chloride. In particular, polyesters such as cellulose acetate butyrate and cellulose esters are preferred for improving transfer sensitivity.

[0012] Then, a conductive inorganic filler, an organic filler and other additives are mixed together with a solvent in a binder resin to prepare a coating for forming a back coat. The back coat layer can be formed on the substrate in the form of a substrate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments 1 to 4 and comparative examples 1 to 5 of a thermal transfer printing paper to which the present invention is applied will be described with reference to FIG. Is not limited to Examples 1 to 4.

A synthetic paper (trade name: FPG-150, manufactured by Oji Yuka Co., Ltd.) having a thickness of 150 μm is prepared as the sheet-like base material 2 and has the following composition so that the dry film thickness is 10 μm on the surface. The coating material for forming a dye receiving layer was applied and dried at 120 ° C. for 2 minutes.

[0015] 100 parts by weight of polyester resin (trade name: Byron 200, manufactured by Toyobo Co., Ltd.) 100 parts by weight of methyl ethyl ketone 300 parts by weight of toluene

Next, with the composition of the back coat layer 4 as shown in Table 1, the compositions of Examples 1 to 4 of the present invention and Comparative Examples 1 to 5 were used.
To form a coating for forming the back coat layer 4 on the surface of the substrate 2 opposite to the surface on which the dye receiving layer 3 is formed so as to have a dry film thickness of 1 μm. This was cured to produce a thermal transfer printing paper 1.

[0017]

[Table 1]

Then, the prepared samples (Examples 1 to 4)
And each of Comparative Examples 1 to 5 were evaluated for surface electric resistance, continuous running test, set-off, and adhesion to the sheet-like substrate 2 under the following conditions. Shown in

The electric resistance of the surface electric resistance back coat layer 4 was measured with an electric resistance measuring device (made by Shishido Electric Co., Ltd.).

Continuous running test 100 samples of each sample were transferred to a sublimation thermal transfer printer (trade name UP
5500, manufactured by Sony Corporation), and continuously performed steer-step printing of 12 gradations, and evaluated by the number of abnormal stops during printing.

[0021] After printing the black solid image smearing dye receiving layer 3, superposed to the plane of the backcoat layer 4 of thermal transfer printing paper 1 surface and unused the dye-receiving layer 3, 50 g / cm ² Pressure of 60 ° C
For 2 days, and the optical density of the dye transferred to the back coat layer 4 was measured using a Macbeth densitometer.

An adhesive tape is stuck to the surface of the back coat layer 4 of the thermal transfer printing paper 1 which is not used for adhesion, and the state of peeling of the back coat layer 4 from the sheet-like substrate 2 when the adhesive tape is peeled off is shown. Evaluation was made by visual observation. When there was no peeling, it was evaluated as ○, and when there was peeling, it was evaluated as x.

[0023]

[Table 2]

As is clear from Table 2, in Examples 1 to 4 to which the present invention was applied, the results satisfied all of the surface electric resistance, the continuous running test, the set-off, and the adhesion to the sheet-like substrate 2. Met. Without adding any conductive inorganic filler,
In Comparative Example 2 and Comparative Example 5 in which 100 parts by weight of the organic antistatic agent was added, although the surface electric resistance was almost the same as that in Example 1, the set-off values were as large as 0.21 and 0.28. Yes, the addition of the organic antistatic agent resulted in greatly deteriorating the set-off inhibiting property. In the case where only 10 parts by weight of an organic antistatic agent was added and no conductive inorganic filler was added as in Comparative Example 1, 10
There were multiple abnormal stops. Then, as in Comparative Example 3, the amount of the conductive inorganic filler added was 3/2 of that in Examples 1-4.
In the case where 20 parts by weight of 0 to 3/5 was added, there were 10 abnormal stops during the continuous running test, and as in Comparative Example 4, the amount of the conductive inorganic filler added was 1/1 of Examples 1-4. 1
When 20 parts by weight of 0 to ／ was added, the result was that the adhesion to the sheet-like substrate 2 was deteriorated.

[0025]

According to the photographic paper for thermal transfer of the present invention, there is provided a photographic paper for thermal transfer having good runnability without stopping the printer abnormally while maintaining the set-off inhibiting property of the back coat layer. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a photographic paper for thermal transfer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Thermal transfer printing paper, 2 sheet-like base materials, 3 ... Dye receiving layer, 4 ... Back coat layer

Claims (3)

[Claims] 1. A thermal transfer printing paper in which a dye-receiving layer is formed on one surface of a sheet-like base material and a backcoat layer having a binder resin is formed on the other surface, wherein the backcoat layer is formed of 0.1. A photographic paper for thermal transfer, comprising a conductive inorganic filler having a particle diameter of 1 μm or more and 3 μm or less. 2. The method according to claim 1, wherein the conductive inorganic filler is at least one of calcium carbonate, titanium oxide, tin oxide, zinc oxide, silicon oxide, zinc sulfide, and barium sulfide subjected to a conductive treatment. Item 6. The photographic paper for thermal transfer according to Item 1. 3. The thermal transfer printing paper according to claim 1, wherein a weight ratio of the conductive inorganic filler to the binder resin is 0.5 or more and 3 or less.