JP3279724B2 - 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 heat transfer receiving sheet (hereinafter, abbreviated as receiving sheet) for forming a dyed image by transferring a sublimable dye by heat.
More specifically, when used in a dye thermal transfer printer, it accepts an image forming dye such as a thermally transferred sublimation dye and causes print curl (indicating curl of a recorded image).
The present invention relates to a receiving sheet which is small in size and has no paper ejection trouble after printing (indicating after printing).

[0002]

2. Description of the Related Art In recent years, a thermal transfer type color hard copy, particularly a dye thermal transfer printer capable of printing a clear full-color image, has attracted attention. The dye thermal transfer printer overlaps a receiving sheet with an ink ribbon printed with a sublimation dye of three colors of yellow, magenta, and cyan, or four colors of black in this order between a thermal head and a platen roll, The dye is transferred and diffused on the receiving sheet by heating with a thermal head. At this time, the receiving sheet rotates or reciprocates three or four times around the thermal head after yellow printing to form a full-color image. In order to transfer and form high-quality prints on a receiving sheet at a high speed by such a dye thermal transfer printer, a dye receiving layer mainly composed of a resin which is easily dyed with a sublimable dye is formed on a sheet-like support. The provided receiving sheet is used.

[0003] The receiving sheet may be in the form of a roll or a sheet-like piece depending on the type of printer, but most receiving sheets are used as sheet-like pieces. In order for the sheet-shaped receiving sheet to be fed, printed and discharged without trouble, the coefficient of friction between the receiving sheet, the coefficient of friction between the receiving sheet and the transport roll, the thickness, rigidity, dimensional stability of the receiving sheet,
Curling etc. becomes a problem. Among them, curling of the receiving sheet is a major cause of paper feeding and paper ejection problems. Blank sheet curl of the receiving sheet , that is, of the receiving sheet before printing
If the curl is large, the sheet is caught by a pickup roller for paper feeding, a roll or a guide inside the printer, and misfeeding or jamming occurs. Further, even when the blank curl is flat, misfeed may occur. This is because, since the receiving sheet is conveyed while being held by the roll in the printer, it is preferable that the receiving sheet has a curl of an appropriate size along the curved surface of the roll. In particular, when the rigidity of the receiving sheet is large, the receiving sheet is hard to bend, causing jamming.

Further, since high heat is applied by the thermal head at the time of printing, the receiving sheet is thermally deformed, and the generated curl causes a paper ejection error. This is in addition to shrinkage of the dye receiving layer itself,
This is because a biaxially stretched film containing an inorganic pigment and a polyolefin as main components and containing voids is often used.
Such a biaxially stretched film containing voids has the advantage that a uniform and high-density print can be obtained due to advantages such as a relatively uniform thickness, flexibility, and low thermal conductivity. However, when a high temperature is applied during printing, the film contracts in the stretching direction due to residual stress when the film is stretched, and curling or wrinkling occurs in the receiving sheet.

As a method of improving the curl caused by printing, there is an attempt to prevent print curl by using a substrate having a small heat shrinkage. As a laminated substrate with a relatively small heat-shrinkable substrate or a substrate with a large elastic modulus as the core, a biaxially stretched film containing voids containing both the above-mentioned inorganic pigment and polyolefin as main components on both surfaces. Use is an example. However, a difference in expansion and contraction ratio due to thermal printing from one side remained, and curling due to printing was not completely eliminated.

In Japanese Patent Application Laid-Open No. 62-152793, in a heat transfer sheet having a dye receiving layer provided on one side of a synthetic paper substrate, the synthetic paper substrate is heated at 60 to 140 ° C., preferably 11 ° C.
A method of preventing curling by heating at a temperature of 0 ° C. to 130 ° C. for 2 to 3 seconds or more has been proposed. In this method, a film is heat-treated in advance to reduce shrinkage due to heat during printing. That is, it has been reported that the synthetic paper base material is continuously brought into contact with a heat roll or passed through a heated oven to reduce residual stress by heat and reduce the heat shrinkage.

Japanese Patent Application Laid-Open No. Sho 63-214484 proposes an attempt to prevent curling by applying a receiving layer on one side of a synthetic paper, drying it, and then bonding a backing material to the other side. . Further, Japanese Patent Application Laid-Open No. Sho 64-44481 proposes that a curl preventing treatment layer is provided on the back surface of a substrate to prevent curling during storage.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a receiving sheet for use in various dye thermal transfer printers. The present invention relates to a receiving sheet having a specific stiffness, by giving a specific size and direction to a blank curl of a receiving sheet. An object of the present invention is to provide a receiving sheet that is stable in sheet feeding, has a small curl due to heat at the time of printing, has excellent transportability, and is free from troubles in sheet discharging.

[0009]

The cause of curling due to the heat of printing is the heat shrinkage of the dye receiving layer of the receiving sheet and the sheet-like support as described above. In the above-described conventional technique, as a method for preventing the curl, the thermal contraction rate of the sheet-like support itself is reduced. The present inventors have conducted intensive studies in order to prevent the print curl at the time of printing, and as a result, have found that it is only necessary to apply another force to the receiving sheet to offset the force caused by the heat shrinkage. That is, the stiffness of the sheet-like support is increased, and a repulsive force against heat shrinkage is provided.

However, if only the stiffness of the sheet-like support is increased, the receiving sheet becomes difficult to bend,
This may cause jamming during paper feeding or transport inside the printer. Therefore, it was found that when a specific size and direction were given to the blank curl of the receiving sheet, troubles in paper feeding and conveyance could be prevented. That is, since the receiving sheet is often bent with the dye receiving layer surface side being convex during conveyance, it has been found that if a blank paper curl having the dye receiving layer surface side convex is applied in advance, it can be conveyed without jamming. Reached.

Therefore, the present invention provides a sheet-like support, and a dye-receiving layer formed on one surface of the sheet-like support and containing a dye-dyeable resin as a main component, and having a width of 9 mm.
Thermal transfer receiver with a size of 9.6 mm and length of 140.8 mm
When the length direction of the curl that is convex to the dye receiving layer side of the sheet was placed dyed charge receptive layer side on a flat side down,
The maximum height of the four corners is 2 mm or more and 10 mm or less, and TA
Measurement method of stiffness of paper described in PPI T543pm84
The stiffness in the length direction of the thermal transfer receiving sheet measured in accordance with the above is not less than 710 standard Gurley units.

Examples of the sheet-like support used in the present invention include a paper base such as coated paper, art paper and woodfree paper, a laminated paper obtained by laminating a resin such as polyethylene on the front and back of a paper base, polyester, nylon and polyolefin. Examples thereof include films of polypropylene (for example, polypropylene) and films having a multilayer structure having voids, which are biaxially stretched and mainly composed of a polyolefin resin and an inorganic pigment. further,
What laminated | stacked these papers and films suitably and used also can be used.

The thickness of the sheet-like support used in the present invention is preferably from 20 μm to 300 μm. It has a thickness of 2
When it is 0 μm or less, its mechanical strength becomes insufficient,
This is because the hardness of the receiving sheet and the repulsive force against deformation become insufficient, and the curl generated at the time of printing cannot be sufficiently prevented. On the other hand, if the thickness exceeds 300 μm, the thickness of the obtained receiving sheet becomes excessive. That is, in a printer having a predetermined capacity, the receiving sheet storage capacity is limited, and therefore, an increase in the thickness may cause a decrease in the number of printers to be stored, or may increase the volume of the printer, making it difficult to make the printer compact. Because there is.

The dye receiving layer provided on one surface of the sheet-like support in the receiving sheet of the present invention contains, as a main component, a dye-dyeable resin dyed with a sublimable dye transferred from an ink ribbon. . As such a dyeing resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate resin, acrylic resin,
Examples include cellulose derivatives. The thickness of the dye receiving layer is preferably from 1 to 10 μm, more preferably from 2 to 10 μm.
７7 μm. If the dye receiving layer is too thin, there are disadvantages such as deterioration of the image and reduction in gloss of the printed surface. On the other hand, if the thickness is too large, the effect is saturated and not only is uneconomical, but also the print density may decrease.

The surface of the dye receiving layer of the receiving sheet of the present invention has
In order to prevent fusion with the ink ribbon due to heating of the thermal head during printing, it is preferable to add a cross-linking agent for the resin, a slipping agent, or a release agent as necessary. If necessary, other additives such as an antioxidant, a pigment, and an ultraviolet absorber may be added. These additives may be mixed with the main component of the receiving layer and applied, or may be applied as a separate coating layer on the receiving layer. If necessary, another layer, for example, an antistatic layer or a lubricant layer may be provided on the back surface of the sheet-like support in order to improve the running property of the receiving paper. The dye receiving layer and other coating layers of the present invention can be formed by coating and drying using a coater such as a bar coater, a gravure coater, a comma coater, a blade coater, an air knife coater, etc. according to a conventional method.

The following various methods can be used as means for imparting a blank sheet curl having a convex surface on the dye receiving layer side to the receiving sheet. A dye-receiving resin crosslinking agent is added to the dye-receiving layer, the dye-receiving layer coating material is applied, and after drying, crosslinking is performed while heating the receiving sheet in a state of being wound up in a roll shape, and white paper curl is applied. That is, the receiving sheet is wound up in a roll shape such that the surface on which the dyeing receiving layer is formed is located on the outer surface of the roll.
Crosslinking of the dye receiving layer is performed while performing heat treatment at a temperature of 〜60 ° C. and a relative humidity of 75% or less to obtain a receiving sheet having a white paper curl having a convex surface on the dye receiving layer forming surface side.

A dye-receiving layer is formed on a multi-layered sheet-like support in which a film or paper is used as a core material and films are bonded on the front and back sides. At this time, the heat shrinkage of the film on the dye receiving layer forming side is made smaller than that of the film on the opposite side. Further, by preheating the sheet-like support before coating the dye receiving layer paint, a receiving sheet having a white paper curl having a convex surface on the side on which the dye receiving layer is formed can be obtained. A dye-receiving layer is formed on a multi-layered sheet-like support in which a film or paper is used as a core material and films are bonded on the front and back sides. At this time, by making the thickness of the film on the side where the dye receiving layer is formed smaller than that of the film on the opposite side, a receiving sheet having a white paper curl having a convex side on the side where the dye receiving layer is formed is obtained.

A dye receiving layer is formed on a sheet-like support obtained by extruding and laminating a resin on the front and back of paper. At this time, by making the amount of lamination of the resin on the dye receiving layer forming side smaller than the amount of laminating the resin on the opposite side, a receiving sheet having a white paper curl having a convex surface on the side of forming the dye receiving layer is obtained. In a sheet-like support obtained by laminating two types of films, the tension at the time of laminating the film on the dye-receiving layer forming side is made smaller than the tension at the time of laminating the film on the opposite side, thereby forming the dye-receiving layer. A receiving sheet having a white paper curl whose convex side is convex is obtained. As described above, blank curls required for the present invention can be provided by any of the methods, and there is no problem if blank curls are provided by other methods.

[0019]

EXAMPLES Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.
In the following, parts are parts by weight of solid content unless otherwise specified. Further, the substance names marked with * used in the respective examples and comparative examples are trade names. Example 1 In order to form a dye receiving layer on one surface of a white PET film (* E20 manufactured by Toray Industries, Inc.) having a thickness of 188 μm, paint-1 having the following composition was applied by a die coating method at a solid content of 8 g / m ^2. Worked and dried. After drying, the receiving sheet was wound up in a roll shape such that the surface on which the dye receiving layer was formed was on the outside, was immediately moisture-proof packed, and was left in a heat treatment room for 5 days. The temperature in the heat treatment chamber was controlled at 45 ± 3 ° C., and the relative humidity was controlled at 35 ± 5%. The roll had a winding diameter of 700 mm and was arranged horizontally so as not to come into contact with the floor or the like.

Coating-1 Component Weight parts Polyester resin (* Vylon 200, manufactured by Toyobo) 100 Silicone oil (* SH3746, Toray Dow Corning 3 Silicone) Isocyanate (* Coronate L, manufactured by Nippon Polyurethane) 5 Mixture of the above composition It was dissolved in a mixed solvent of toluene: MEK = 5: 1 to obtain a 15% solution.

Example 2 As an inorganic pigment, a biaxially stretched 50 μm-thick multilayer film (* Yupo FPG50, containing a polyolefin containing about 30% of calcium carbonate and the like as a main component)
(Width: 1 m, length: 2000 m, manufactured by Oji Yuka Synthetic Paper)) with a tension of 20 kg / m.
Heat treatment was performed in an oven at 24 ° C. for 24 hours. The heat shrinkage in the longitudinal direction of this polyolefin film is 0.5% when untreated.
And 0.2% after heat treatment. The heat shrinkage in the lateral direction was 0.45% in the case of no treatment, and 0.05% after the treatment.

A 120 μm thick cast coated paper (* O
K Enamel Coat 127.9 Oji Paper Co., Ltd.) as a core material, the heat-treated polyolefin film on the front side, and the same but unheated polyolefin film on the back side dry-laminated with a urethane-based adhesive The sheets were laminated and laminated to form a sheet-like support. After preheating the sheet-like support in an oven at 120 ° C. for 1 minute, paint-2 having the following composition was added to the roll-treated polyolefin film at a solid content of 5%.
The coating was dried at a rate of g / m ² to obtain a receiving sheet.

Paint-2 component parts by weight Polyester resin (* Vylon 200, manufactured by Toyobo) 100 Silicone oil (* X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 Isocyanate (* Coronate L, manufactured by Nippon Polyurethane) 5 The above composition Was dissolved in a mixed solvent of toluene: MEK = 5: 1 to obtain a 15% solution.

Example 3 A 120 μm-thick cast-coated paper (* OK Enamel Coat 127.9 manufactured by Oji Paper) was used as a core material, and a polyolefin containing about 30% of calcium carbonate or the like as an inorganic pigment was mainly provided on the front and back sides. Included as a component, biaxially stretched film with a thickness of 50 μm and 60 μm with a multilayer structure (* Yupo FPG50, FPG60, manufactured by Oji Oil Chemical Synthetic Paper)
Were laminated with a urethane-based adhesive by a dry lamination method to prepare a sheet-like support. To form a dye receiving layer on the 50 μm-thick polyolefin film side of this sheet-like support, coating-2 was applied at a rate of 5 g / m ² and dried to obtain a receiving sheet.

Example 4 A layer of 30 g / m ² of high-density polyethylene (* Yukalon LY20, manufactured by Mitsubishi Yuka) was coated on the surface side of coated paper (* OK coated 127.9 manufactured by Oji Paper) having a thickness of 100 μm. A layer of 40 g / m ² of low-density polyethylene (* Yukaron LK50, manufactured by Mitsubishi Yuka) was provided on the surface side by extrusion lamination. Furthermore, on the high-density polyethylene side, paint-
2 was applied and dried at a rate of 5 g / m ² to obtain a receiving sheet.

Example 5 A 50 μm thick white polyethylene terephthalate (PET) film (* Lumirror 50E63) coated with a dye receiving layer of paint-2 on one side and an adhesive on the other side
Toray Co., Ltd.) and a 100 μm-thick white PET film (* U2 Teijin Co., Ltd.) coated with a release agent were adhered so that the pressure-sensitive adhesive surface and the release agent surface were overlapped. At this time, the tension on the side of the white PET of 50 μm was 2 times the tension of the white PET of 100 μm.
/ 3 or less to obtain a receiving sheet.

Comparative Example 1 A receiving sheet was produced in the same manner as in Example 1. However, a biaxially stretched 150 μm-thick multilayer film (* Yupo FPG150, Oji Yuka Synthetic Paper) containing, as a main component, a polyolefin containing about 30% of calcium carbonate or the like as an inorganic pigment as a sheet-like support Was used. Comparative Example 2 A receiving sheet was produced in the same manner as in Example 1. However, the heat treatment was performed by winding the receiving sheet into a roll so that the surface on which the dye receiving layer was formed was located inside.

Comparative Example 3 A receiving sheet was produced in the same manner as in Example 2. However, the heat treatment was not performed on the polypropylene film on the dye receiving layer forming side, and an untreated polyolefin film was used on both sides. Comparative Example 4 A receiving sheet was produced in the same manner as in Example 4. However, a dye receiving layer was formed on the low density polyethylene side. Comparative Example 5 A receiving sheet was produced in the same manner as in Example 5. However, 1
A dye receiving layer was formed on the white PET side of 00 μm.

Evaluation Test Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2, 3,
4, 5, each receiving sheet is 99.6 mm in width and 14 in length.
The sheet was cut to 0.8 mm, and the white paper curl was measured. For the measurement of the blank curl, the dye receiving layer was placed on a flat surface with the dye receiving layer facing down and up, and the maximum height of each of the four corners was measured. Also T
The stiffness of the receiving sheet was measured according to APPI T543 pm84.

The cut receiving sheet was tested for transportability using a sublimation video printer (CP-11, manufactured by Mitsubishi Electric Corporation), and the curl after printing was measured. Printing was performed by inputting a dot pattern signal from a signal generator (trade name: C13A2 manufactured by Shibasoku). The transportability was evaluated by printing 20 sheets continuously, and was evaluated as “good” when there was no transport trouble and “bad” when there was a transport trouble. The curl after printing was measured in the same manner as for blank paper curl. Table 1 shows the results.

[0031]

[Table 1]

[0032]

The receiving sheet of the present invention can be fed smoothly when used in a dye thermal transfer printer and has a small print curl after printing. Yes, it is of high practical value.

Continuation of the front page (72) Inventor Yukio Kusaka 1-10-6 Shinonome, Koto-ku, Tokyo Oji Paper Co., Ltd. Inside the Product Research Laboratory (56) References JP-A-3-142285 (JP, A) JP-A-3 JP-A-231895 (JP, A) JP-A-4-144789 (JP, A) JP-A-4-187494 (JP, A) JP-A-4-329189 (JP, A) JP-A-5-8555 (JP, A) JP-A-5-32076 (JP, A) JP-A-5-50623 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (1)

(57) [Claims] 1. A thermal transfer receiving sheet having a sheet-like support and a dye-receiving layer formed on one surface of the sheet-like support and containing a dye-dyeing resin as a main component.
And heat of 99.6 mm in width and 140.8 mm in length
When the transfer receiving sheet is placed on a flat surface with the dye receiving layer surface side facing down, the maximum height of the four corners is 2 mm or more and 10 mm or less. And the stiffness of paper described in TAPPI T543pm84 .
Length direction of thermal transfer receiving sheet measured according to measurement method
A heat transfer receiving sheet having a stiffness of at least 710 standard Gurley units.