JP3367250B2 - Thermal transfer receiving sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer receiving sheet (hereinafter simply referred to as a receiving sheet) which forms a dyed image by transferring a sublimable dye by heat. More specifically, the present invention is a thermal transfer printer that is capable of forming a color dyed image by using a multicolor ink ribbon in a thermal transfer printer, in which the image position of each color is less displaced and the sharpness of the image is good. The present invention relates to a receiving sheet in which two or more receiving sheets do not overlap and do not feed at the same time in the process of printing in the apparatus.

[0002]

2. Description of the Related Art A thermal transfer type color hard copy, particularly a dye thermal transfer printer capable of printing a clear full-color image has been attracting attention. Dye thermal transfer printers mainly use a resin that is easily dyed with a sublimable dye on a dye layer surface of an ink ribbon in which a sublimable dye layer is printed on a base film and a sheet-like support (hereinafter simply referred to as a substrate). An image is formed by superimposing the receiving layer surface of a receiving sheet provided with a receiving layer as a component, and by transferring heat from a thermal head, a dye at a required position in the sublimation dye layer on the receiving layer in a required concentration. It is a thing.

Generally, when printing an image with a thermal transfer printer, a receiving sheet is wound around a cylindrical roller lined with rubber called a platen roll in the apparatus,
The ink ribbon is superposed on this, the thermal head is positioned on the back surface of the ink ribbon, and the platen roll is rotationally driven, the ink ribbon is driven, and the voltage of the thermal head is adjusted and synchronized. To obtain a full-color image, do this operation for cyan, magenta, and yellow.
The color ink ribbons are repeated, or a black ink ribbon is added thereto and the color ink ribbons are repeated to obtain a full-color image by superposing each color. However, since this rotation operation is repeated three to four times, the receiving sheet slightly moves on the platen roll during this operation, and a phenomenon (color misregistration) occurs in which prints of each color are slightly deviated, resulting in a sharp image. There was a problem of deterioration.

It has already been attempted to improve color misregistration by defining the smoothness of the back surface layer and increasing the friction coefficient (Japanese Patent Laid-Open No. 62-170391). However,
If the back surface frictional resistance of the receiving sheet is simply increased, even if the color shift is improved, two or more receiving sheets are fed from the receiving sheet stock section of the thermal transfer printer and run while feeding. A new problem (double feed) occurs. Further, a method for determining the friction coefficient between the front surface and the back surface of the receiving sheet to solve the above-mentioned problem (double feeding) (Japanese Patent Laid-Open No. Sho 6-62)
No. 3-236690) has been proposed, but the friction coefficient is a relationship under a constant load condition and is not always in accordance with the actual situation, and it is difficult to solve color misregistration and double feeding at the same time. .

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a receiving sheet for use in various dye thermal transfer printers, and provides a receiving sheet which is improved in color misregistration and does not double feed when a color image is printed by a full color printer. It is what

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, in a thermal transfer receiving sheet having a back coating layer, by blending a specific silica pigment in the back layer, The inventors have found that the problems of color misregistration and double feeding can be solved at the same time, and completed the present invention. That is, the thermal transfer receiving sheet according to the present invention comprises a sheet-like support, a receiving layer containing a dye-dyeable resin as a main component formed on one surface of the sheet-like support, and the opposite of the sheet-like support. In a thermal transfer receiving sheet having a back coating layer formed on the surface, the back coating layer contains an adhesive and a silica pigment as main components, and the silica pigment has an average particle diameter of 3 to 10 μm, and the silica The content of the pigment is 5 to 15 parts by weight with respect to 100 parts by weight of the adhesive. In the thermal transfer recording sheet of the present invention, the center line average roughness (Ra) of the surface of the back coating layer according to JIS-B0601 is 0.3 to 0.9 μm.
And the ten-point average roughness (Rz) is preferably 3 to 7 μm.

[0007]

The base material used in the present invention is coated paper,
Paper base materials such as art paper and high-quality paper, laminated paper obtained by melt-extruding thermoplastic resin such as polyethylene on the front and back of the paper base material, polyethylene terephthalate, nylon, polystyrene and polyolefin (eg polypropylene)
Examples of the above film, or a film having a multi-layered structure containing a polyolefin resin and an inorganic pigment as main components and having biaxially stretched voids, and the like. Furthermore, it is also possible to use a laminated structure in which these are laminated. The thickness of the substrate is 100 ~
300 μm is preferable. When the thickness is 100 μm or less, the mechanical strength is insufficient, the hardness of the receiving sheet obtained therefrom and the repulsive force against the deformation are insufficient, and the curling of the receiving sheet generated during printing is sufficient. There are inconveniences that cannot be prevented. On the other hand, when it exceeds 300 μm, the thickness of the obtained receiving sheet becomes excessively large and it becomes difficult to handle it in a thermal transfer printer.

The back coating layer of the present invention contains an adhesive and a silica pigment as main components. As the silica pigment to be blended in the back surface coating layer, a product whose main component is silicon oxide can be selected and used from commercial products, and may be a precipitation type or a gel type. The average particle diameter of the silica pigment is preferably 3 to 10 μm. Further, in order to improve the affinity with the adhesive, a surface treatment can be applied if necessary. If the particle size of the silica pigment is too small or too large, it is difficult to exert the effects of the present invention. That is, if it is too small, it is difficult to improve the color misregistration, and if it is too large, the color misregistration is improved, but multi-feeding is likely to occur, and further, the surface of the back surface impairs the commercial value. The average particle size of the silica pigment is a value measured by a sedimentation particle size measuring device (Shimadzu SA-CP3).

As the adhesive used for the back surface coating layer, a known polymer binder can be arbitrarily selected and used. For example, polyester binder, vinyl acetate binder, polyurethane binder, melamine binder, urea binder, acrylic binder, phenol binder, butadiene copolymer latex, vinyl acetate resin emulsion, acrylic emulsion, polyolefin emulsion, cellulose derivative, Examples thereof include polyvinyl alcohol. Of these, acrylic binders are preferable. Further, a small amount of a known crosslinking agent may be added to these adhesives to crosslink and cure them. For example, an epoxy type crosslinking agent or an isocyanate type crosslinking agent can be used. Aldehydes, amines,
It is also possible to use a cross-linking agent of polyamides, an initial condensate of melamine or urea resins, hydrazines and persulfates. The coating amount of the back coating layer is not particularly limited,
The range of 0.05 to 5 g / m ² is suitable, if it is too small, the effect is not exhibited, and if it is excessively increased, further effect cannot be expected, and the cost is increased and it is not practical.

Further, the surface roughness of the back surface is, of course, closely related to the particle size of the silica pigment,
In addition, it may be affected by coating and drying conditions, such as the amount of silica pigment used and the difference in paint viscosity depending on the concentration and type of binder in the paint. In the present invention, the surface roughness of the backside coating layer has a center line average roughness (Ra) according to JIS-B0601 of 0.3 to 0.9 μm and a ten-point average roughness (Rz) of 3 to. The range of 7 μm is preferable from the viewpoints of color misregistration, double feeding, and commercial value. R
When the value of a or Rz is smaller than the lower limit, color misregistration becomes large and the image quality is deteriorated. On the other hand, when the value of Ra or Rz exceeds the upper limit, double feeding is likely to occur. More preferably, the center line average roughness (Ra) is 0.4 to 0.6 μm,
Moreover, the ten-point average roughness (Rz) is in the range of 3 to 5 μm.

In the receiving sheet of the present invention, the receiving layer provided on the surface of the base material contains as a main component a dye-dyeing resin dyed with a sublimable dye transferred from the ink ribbon. The performance required of the dyeable resin needs to have a high affinity with the sublimable dye of the ink ribbon in order to obtain a high density printed image. Examples of such dyeable resin include polyester resin, polycarbonate resin, vinyl chloride copolymer, and cellulose derivative. The coating amount of the receiving layer is generally 3 to 10 g / dry weight.
It is preferably m ² . If the coating amount of the receiving layer is too small, the surface of the base material may not be completely covered, which may lead to deterioration of image quality or the phenomenon that the base material and the ink ribbon are adhered (fusion). . Further, if the coating amount of the receiving layer is too large, not only the effect is saturated and it is uneconomical, but also the strength of the receiving layer is lowered, the distance between the receiving layer and the base material is increased, and the heat insulating effect of the base material is sufficiently exerted. However, the image density is reduced.

In the receiving layer of the present invention, a resin cross-linking agent, a slip agent, a release agent, a pigment, etc. may be added, if necessary, for the purpose of preventing fusion with the ink ribbon due to heating of the thermal head during printing. It is preferable to add it. If necessary, other additives such as colored pigments, fluorescent dyes, colored dyes, ultraviolet absorbers, antioxidants, and ceramic fine particles may be added. It is also possible to provide an overcoat layer containing a release agent such as silicone. As the pigment, silica pigment, titanium pigment, calcium carbonate, talc, clay, plastic pigment, or the like can be used. Of these, silica pigments are preferably used in terms of whiteness and image quality, and the average particle size thereof is preferably about 1 to 12 μm.
About 2 to 15 parts by weight is suitable for 100 parts by weight. The surface roughness of the receiving layer is not particularly limited, but in view of image quality, the center line average roughness (Ra) is usually used.
Is 0.6 μm or less, preferably 0.2 to 0.6 μm, and the ten-point average roughness (Rz) is 5 μm or less, preferably about 2 to 4 μm, and the receiving sheets are set in a stacked state. In this case, the effect of the back surface coating layer of the present invention is sufficiently exerted in improving color misregistration and double feeding.

In the receiving sheet of the present invention, in addition to the receiving layer and the back coating layer, an intermediate adhesive layer is provided to enhance the adhesiveness between the base material and the coating layer, and an antistatic layer is provided to remove static electricity. It can also be provided. The receiving layer and the back coating layer and other coating layers of the receiving sheet of the present invention, bar coater, gravure coater, comma coater, blade coater, air knife coater, gate roll coater,
It can be manufactured by coating with a coater such as the above and drying.

[0014]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, "part" in an Example shows a "solid content weight part." Example 1 Polyethylene terephthalate (PET) having a thickness of 50 μm
A multilayer structure film (trademark: YUPO FPG50, FPG6) having a thickness of 50 μm and 60 μm, which is obtained by biaxially stretching a polyolefin containing an inorganic pigment as a main component on both sides of the film.
No. 0, made by Oji Yuka Synthetic Paper) was laminated by a dry lamination method using a polyester adhesive. Coating-B1 was applied as a backside coating layer on the side of the 60 μm multilayer structure film by the bar coating method at a solid content of 0.5 g / m ² and dried. Further, Paint-A1 was applied as a receiving layer on the side of the multi-layered film having a thickness of 50 μm at a solid content of 5 g / m ^{2 by} a die coating method and dried to complete a receiving sheet. Paint-B1 acrylic resin (Trademark: Ricabond SA-R615A, manufactured by Chuo Rika) 100 parts Epoxy curing agent (Trademark: Ricabond SA-R615B, manufactured by Chuo Rika) 5 parts Conductive agent (trademark: Saftomer STH2000H, manufactured by Mitsubishi Petrochemical) 15 Part silica pigment (trademark: P78A, manufactured by Mizusawa Chemical Industry Co., Ltd.) A mixture of 8 parts or more was diluted with a mixed solution of IPA: water = 8: 2 to obtain a 12% solution. Paint-A1 saturated polyester resin (trademark: Byron 200, manufactured by Toyobo) 100 parts Silicone oil (trademark: KF101 manufactured by Shin-Etsu Chemical) 5 parts Isocyanate (trademark: Coronate L, manufactured by Nippon Polyurethane Industry) 5 parts Silica (trademark: C212, Mizusawa) Made by Kagaku Kogyo Co., Ltd., average particle size 2.2 μm) Mix 8 parts or more of toluene: methyl ethyl ketone = 5: 1
15% solution of the mixed solvent of.

Example 2 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed using the following paint-B2. Paint-B2 acrylic emulsion (trademark: A4100, manufactured by Kanebo NSC) 100 parts Epoxy curing agent (trademark: YC-95, manufactured by Kanebo NSC) 5 parts Conductive agent (trademark: Chemistat 6120, manufactured by Sanyo Kasei) 15 parts Silica pigment (trademark) : P510, manufactured by Mizusawa Chemical Industry Co., Ltd.) 13 parts or more of the mixture was diluted with water to obtain a 12% solution.

Example 3 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed using the following paint-B3. Paint-B3 polyvinyl alcohol (trademark: NL-05, manufactured by Nippon Synthetic Chemical Industry) 100 parts trimethylolmelamine 5 parts Conductive agent (trademark: Versa TL125, manufactured by Kanebo NSC) 15 parts Silica pigment (trademark: P78C, manufactured by Mizusawa Chemical Industry) ) 10 parts or more of the mixture was diluted with water to give a 12% solution.

Example 4 A receiving sheet was prepared in the same manner as in Example 1 except that 5 parts of a silica pigment (trademark: P78A, manufactured by Mizusawa Chemical Industry Co., Ltd.) was used in the preparation of the back coating layer coating material-B1. .

Example 5 A receiving sheet was prepared in the same manner as in Example 3 except that 15 parts of silica pigment (trademark: P78C, manufactured by Mizusawa Chemical Industry Co., Ltd.) was used in the preparation of the back coating layer coating material-B3. .

Comparative Example 1 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed using the following paint-B4. Paint-B4 polyvinyl alcohol (trademark: NL-05, manufactured by Nippon Synthetic Chemical Industry) 100 parts trimethylolmelamine 5 parts Conductive agent (trademark: Versa TL125, Kanebo NSC) 15 parts A mixture of 12 parts or more diluted with water. It was a solution.

Comparative Example 2 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed using the following paint-B5. Paint-B5 Styrene Butadiene Rubber (Trademark: 0668, made by Japan Synthetic Rubber) 100 parts Conductive agent (Trademark: Chemistat 6120, made by Sanyo Kasei) 15 parts Silica Pigment (Trademark: P78C, made by Mizusawa Chemical Industry) 20 parts or more of a mixture Diluted with water to a 12% solution.

Comparative Example 3 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed using the following paint-B6. Paint-B6 acrylic copolymer resin (Trademark: Mobile 730, Hoechst Synthetic) 100 parts Conductive agent (Trademark: Chemistat 6120, Sanyo Kasei) 15 parts Silica pigment (Trademark: P603, Mizusawa Chemical Industry) 8 parts or more The mixture was diluted with water to give a 12% solution.

Comparative Example 4 A receiving sheet was prepared in the same manner as in Example 1 except that the back coating layer was formed by using the following paint-B7. Paint-B7 Acrylic resin (trademark: Ricabond SA-R615A, manufactured by Chuo Rika) 100 parts Epoxy curing agent (trademark: Ricabond SA-R615B, manufactured by Chuo Rika) 5 parts Conductive agent (trademark: Saftomer STH2000H, manufactured by Mitsubishi Petrochemical) 15 Part silica pigment (trademark: P78F, manufactured by Mizusawa Chemical Industry Co., Ltd.) A mixture of 10 parts or more was diluted with water to obtain a 12% solution.

[Measurement and Evaluation Method] (1) The average particle size of the silica pigment was measured using a sedimentation particle size measuring device (Shimadzu SA-CP3). (2) The surface roughness of the back coating layer and the receiving layer is JIS-B0.
It was measured by the method of 601. (3) Evaluation of color misregistration and double feeding The above-mentioned receiving sheet was A4 size (210 mm x 297 mm)
Cut into pieces, and commercially available sublimation video printer (trademark: JX-7
(500, manufactured by Sharp), printed, and evaluated. (A ) Color misregistration : A color misregistration was evaluated by printing a test evaluation pattern in which a cross mark was overprinted with ribbons of each color at the same position on a video printer. The cross marks at the four corners of the print were magnified and observed with a microscope to read the maximum color shift. <Evaluation criteria for color misregistration> ⊚: Less than 50 μm, good image quality. ◯: 50 to less than 100 μm, the image quality is practically no problem. X: 100 μm or more, poor image quality, and practical problems. ( B) Double feeding : feeding 100 receiving sheets in succession,
All sheets were continuously printed and the presence or absence of double feeding was evaluated according to the following criteria. <Evaluation criteria for double-feeding> A: No double-feeding occurs at all. ◯: Double feeding 1-2 times, within a practically acceptable range. X: Double feeding three times or more, there is a practical problem. The test results are shown in Table 1.

[0024]

[Table 1]

[0025]

INDUSTRIAL APPLICABILITY The thermal transfer receiving sheet of the present invention relates to a receiving sheet for use in a sublimation dye thermal transfer printer. When a color image is printed by a full-color printer, color misregistration and double feeding are simultaneously improved and the image quality is good. It is of high practical value.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP 62-292485 (JP, A) JP 3-128289 (JP, A) JP 6-51430 (JP, A) JP 3- 128292 (JP, A) JP-A-63-194982 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/38-5/40 B32B 27/00

Claims (2)

(57) [Claims] 1. A sheet-like support, a receiving layer containing a dye-dyeable resin as a main component formed on one surface of the sheet-like support, and an opposite surface of the sheet-like support. In a thermal transfer receiving sheet having a back surface coating layer, the back surface coating layer contains an adhesive and a silica pigment as main components, the silica pigment has an average particle diameter of 3 to 10 μm, and the content of the silica pigment. Is 5 to 100 parts by weight of the adhesive.
A thermal transfer receiving sheet comprising 15 parts by weight. 2. The center line average roughness (Ra) of the surface of the back surface coating layer is 0.3 to 0. 0 based on JIS-B0601.
The thermal transfer receiving sheet according to claim 1, which has a 10-point average roughness (Rz) of 3 to 7 µm.