JP2004009159A - Polishing sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing sheet capable of efficiently removing foreign matter such as dust, attached to a thermal head for thermosensitive recording without deteriorating durability of the thermal head for thermosensitive recording. <P>SOLUTION: A needle type inorganic pigment whose axial ratio of a long axis and to a short axis is more than 10 is contained in a polishing layer as a polishing material on the polishing sheet at least on one single surface of a support body 1 of which the polishing layer 2 is formed to remove the foreign matter attached to the thermal head for thermosensitive recording. In this case, it is favorable to print a method of use of the polishing sheet at least on one single surface of the polishing sheet. <P>COPYRIGHT: (C)2004,JPO

Description

【００３４】
表２に示す結果の通り、長軸と短軸との軸比が１０以上の針状の無機顔料を研磨材として使用している実施例１〜２の研磨シートは、良好な異物除去効果を示したが、粒状の無機顔料を研磨材として使用している比較例１〜３の研磨シートの異物除去効果は十分なものではなかった。
【００３５】
【発明の効果】
本発明の研磨シートによれば、感熱記録用サーマルヘッドに付着している異物を、感熱記録用サーマルヘッドの耐久性を損なうことなく、効率的に除去することができる。
【図面の簡単な説明】
【図１】本発明の研磨シートの断面図である。
【図２】本発明の研磨シートの断面図である。
【符号の説明】
１　支持体、２　研磨層、３　バックコート層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is directed to polishing for removing foreign matter such as dust attached to a heating surface of a thermal recording thermal head provided in a thermal recording printer such as a thermal fusion transfer type printer, a sublimation thermal transfer type printer or a self-coloring type printer. Regarding the sheet.
[0002]
[Prior art]
In the thermal recording method, a heat-melt transfer ink ribbon having a heat-meltable ink layer provided on a substrate or a sublimation heat transfer ink ribbon containing a sublimable heat-transferable (or heat-diffusible) dye on a substrate is used. A thermal transfer recording method in which the ink is transferred to paper or the like by heating with a thermal head for thermal recording, and a coloring agent contained in the thermal layer of the recording sheet is heated by the thermal head for thermal recording to change to a leuco dye. There is a self-coloring type in which an image is formed on the sheet itself. In particular, the sublimation thermal transfer recording method is capable of forming a full-color image with continuous gradation, and is attracting attention as a method for hard-copying a video image. Therefore, the sublimation thermal transfer recording system is expected to be able to form an image comparable to a silver halide photograph.
[0003]
However, foreign matter such as dust may adhere to the heat generating element of the thermal head for thermal recording, and in this case, streaks and unevenness occur in the printed matter, and there is a problem that the print quality is significantly reduced.
[0004]
Therefore, conventionally, only the heat resistance of the back surface of the sublimation thermal transfer ink ribbon or the self-coloring recording sheet that directly contacts the thermal head for thermal recording is used so as not to be damaged by the heat applied from the thermal head for thermal recording. Instead, a heat-resistant lubricating layer having a function of wiping foreign matters such as dust adhered to the thermal head for thermal recording due to external factors has been provided.
[0005]
[Means for Solving the Problems]
However, when foreign matter adheres to the heat generating element of the thermal recording thermal head, the heat-resistant lubricating layer as described above significantly increases the amount of heat generated by the thermal recording thermal head with the recent increase in thermal recording speed. Under the increasing situation, there is a problem that the possibility of occurrence of image sticking with the thermal head for thermal recording increases. In addition, by greatly roughening the wiping ability of the heat-resistant lubricating layer and increasing the polishing effect by using an inorganic pigment having a high hardness, foreign substances adhering to the thermal recording thermal head can be more efficiently removed. Although it is possible to remove it, on the other hand, there is a problem that the heating element surface of the thermal head for thermal recording is excessively worn and the durability of the thermal head for thermal recording is deteriorated.
[0006]
An object of the present invention is to solve the above-described problems of the conventional technology, and efficiently remove foreign matters such as dust attached to the thermal recording thermal head without deteriorating the durability of the thermal recording thermal head. That it can be removed.
[0007]
[Means for Solving the Problems]
The present inventors have found that using a polishing sheet in which a polishing layer is formed on at least one surface of a support, foreign matters adhering to a thermal recording thermal head can be efficiently used without deteriorating the durability of the thermal recording thermal head. The present inventors have obtained an unprecedented finding that an inorganic pigment having a specific shape may be used as an abrasive to be contained in the polishing layer in order to remove well, and completed the present invention based on the finding.
[0008]
That is, the present invention provides a polishing sheet in which a polishing layer is formed on at least one surface of a support for removing foreign matter attached to a thermal head for thermal recording. A polishing sheet comprising an acicular inorganic pigment having an axial ratio of 10 or more. By using the inorganic pigment having such a specific property, it is possible to efficiently remove the foreign matter adhering to the surface of the heating element without causing abrasion of the thermal head for thermal recording.
[0009]
Preferably, at least one surface of the polishing sheet is printed with a method of using the polishing sheet. This makes it possible to eliminate a mistake in feeding the polishing sheet to the thermal recording printer.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0011]
FIG. 1 is a cross-sectional view of an example of the polishing sheet of the present invention for removing foreign matter attached to a thermal head for thermal recording. This polishing sheet has a structure in which a polishing layer 2 containing an inorganic pigment as an abrasive is provided on one surface of a sheet-like support 1. If necessary, a back coat layer 3 may be provided on the other surface of the support 1. Note that, without providing the back coat layer 3, the polishing layers 2 may be provided on both surfaces of the support 1, as shown in FIG.
[0012]
In the present invention, as the support 1, a known sheet-like support, for example, a plastic film such as a polyester film, a polyolefin film, and a cellulose derivative film can be preferably used. In addition, a known photographic paper for sublimation heat transfer recording or an image protection sheet for sublimation heat transfer itself can be used as a sheet-like support.
[0013]
The thickness of the support 1 is not particularly limited, and varies depending on the type of the thermal recording printer, the size and the material of the thermal recording thermal head, the pressure of the thermal recording thermal head against the platen roller, and the like. It is 300 μm.
[0014]
The polishing layer 2 is obtained by dispersing an inorganic pigment as an abrasive in a binder resin. In the present invention, needle-like inorganic pigments are used as the inorganic pigment. This is because the polishing effect is not sufficient when the particles are granular.
[0015]
As for the degree of the needle-like shape of the inorganic pigment, the ratio of the major axis to the minor axis is 10 or more. This is because if the axial ratio is less than 10, foreign substances cannot be sufficiently removed.
[0016]
The inorganic pigment preferably has a Mohs hardness of 6.5 or less in order to minimize abrasion of the thermal head for thermal recording.
[0017]
Examples of such inorganic pigments include titanium oxide, silicon oxide, barium sulfate, calcium carbonate and the like. Specific examples include FT-2000 and FT-3000 manufactured by Ishihara Sangyo Co., Ltd.
[0018]
If the content of the inorganic pigment in the polishing layer 2 is too small, the polishing effect will be low, and if it is too large, the inorganic pigment will fall off to the head. Therefore, when the resin is preferably 100 parts by weight, The content of the inorganic pigment is 30 to 600% by weight, more preferably 50 to 500% by weight.
[0019]
Examples of the binder resin used in the polishing layer 2 include thermoplastic resins such as a modified or unmodified vinyl chloride resin, a polyurethane resin, a polyester resin, and a cellulose ester resin such as cellulose acetate butyrate. In addition, a thermosetting resin, a reactive resin, an electron beam irradiation curable resin, or the like may be used as long as the effects of the present invention are not impaired. These resins may be used together with a curing agent in order to improve the durability of the polishing layer 2. If necessary, an organic pigment, an antistatic material, a lubricant, or the like may be used in addition to the above-described resin.
[0020]
In the polishing sheet of the present invention, a statement explaining that the polishing sheet is a polishing sheet may be printed on at least one surface thereof by a known method.
[0021]
When the backing layer 3 is provided on the polishing sheet of the present invention, the “back” means the back surface of the polishing layer 2, and when the polishing sheet is also used as the sublimation heat transfer type ink ribbon, the backcoat layer 3 is used. Becomes a sublimation heat transfer receiving layer. Therefore, the back coat layer 3 is appropriately selected according to the properties to be additionally provided to the polishing sheet.
[0022]
The polishing sheet of the present invention, on a support, an inorganic pigment as a binder resin abrasive, if necessary, uniformly mixed with a solvent by a known mixing method such as a sand mill, and if necessary, filtered and filtered. To obtain a polishing layer paint, and apply the paint on a support by a known coating method such as a gravure method or a bar coater method, and then dry it.
[0023]
The abrasive sheet of the present invention produced as described above may be fed to a thermal recording printer, similarly to a sublimation thermal transfer recording photographic paper or a self-coloring recording sheet applied to a thermal recording printer.
[0024]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples.
[0025]
Example 1
Various raw materials shown in Table 1 were dispersed using a sand mill, and filtered through a filter having an average diameter of 50 μm to prepare a coating material for a polishing layer.
[0026]
[Table 1] Ingredients by weight
Polyvinyl acetal resin (KS-1, manufactured by Sekisui Chemical Co., Ltd.) 100.0
Modified silicone oil (SF-8427, manufactured by Toray Industries, Inc. Silicone Co., Ltd.) 3.0
Polyisocyanate (Coronate L-45E, manufactured by Nippon Polyurethane Industry Co., Ltd.) 20.0
Titanium oxide (FT-2000, manufactured by Ishihara Sangyo) 50.0
Methyl ethyl ketone 400
toluene 　 　 　　 400
[0027]
The obtained coating material for a polishing layer is applied on one surface of a sheet-like polyester support (trade name: FPG-150, manufactured by Oji Oil Chemical Co., Ltd.) having a thickness of 150 μm so as to have a dry thickness of 3 μm. For 20 hours to form a polishing layer, thereby preparing a polishing sheet.
[0028]
Example 2
Example 1 was repeated in the same manner as in Example 1 except that the needle-like particles “FT-1000” manufactured by Ishihara Sangyo Co., Ltd. were used instead of the needle-shaped particles “FT-2000” manufactured by Ishihara Sangyo. Polishing sheet No. 2 was prepared.
[0029]
Comparative Example 1
Comparative Example 1 was performed in the same manner as in Example 1, except that the granular particles “ET-500W” manufactured by Ishihara Sangyo Co., Ltd. were used as the titanium oxide instead of the needle-shaped particles “FT-2000” manufactured by Ishihara Sangyo. A polishing sheet was prepared.
[0030]
Comparative Example 2
Comparative Example 2 was performed in the same manner as in Example 1 except that titanium oxide particles “KR-310” were used instead of Ishihara Sangyo Co., Ltd. needle particles “FT-2000” as titanium oxide. A polishing sheet was prepared.
[0031]
Comparative Example 3
Comparative Example 3 was performed in the same manner as in Example 1 except that titanium oxide granular particles “KR-410” were used instead of Ishihara Sangyo Corporation needle particles “FT-2000” as titanium oxide. A polishing sheet was prepared.
[0032]
<Characteristic evaluation>
The polishing sheets of Examples 1 and 2 and Comparative Examples 1 to 3 were set in a paper feed cassette of a sublimation thermal transfer printer ("UP-21MD" manufactured by Sony Corporation), and the thermal head was polished in a cleaning mode to be polished. The foreign matter removing effect of the sheet was evaluated. Specifically, a solid black image pattern in which the reflection density of the Macbeth densitometer is 2.45 or more is continuously printed on 500 dedicated printing papers, and the foreign matter is forcibly attached to the thermal head. The adhered thermal head was polished, and the surface of the polished thermal head was checked with an optical microscope (100 times) to determine whether or not foreign matter was completely removed. As a result of the confirmation, a state where there was no foreign matter was judged as “○”, a state where there was a small amount of foreign matter but there was no practical problem was “Δ”, and a state where there was a foreign matter and there was a practical problem was “X”. Table 2 shows the obtained results.
[0033]
[Table 2]

[0034]
As shown in Table 2, the polishing sheets of Examples 1 and 2 using the acicular inorganic pigment having an axis ratio of the major axis to the minor axis of 10 or more as the abrasive have a good foreign matter removing effect. As shown, the foreign matter removing effects of the polishing sheets of Comparative Examples 1 to 3 using the granular inorganic pigment as the abrasive were not sufficient.
[0035]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the polishing sheet of this invention, the foreign material adhering to the thermal head for thermal recording can be removed efficiently, without impairing the durability of the thermal head for thermal recording.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a polishing sheet of the present invention.
FIG. 2 is a cross-sectional view of the polishing sheet of the present invention.
[Explanation of symbols]
1 support, 2 polishing layer, 3 back coat layer

Claims (2)

In a polishing sheet in which a polishing layer is formed on at least one surface of a support for removing foreign matter attached to a thermal head for thermal recording, the polishing layer is used as a polishing material, and the axial ratio of the major axis to the minor axis is 10 or more. A polishing sheet comprising a needle-like inorganic pigment of the above. The polishing sheet according to claim 1, wherein a method for using the polishing sheet is printed on at least one surface of the polishing sheet.

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