JP2940928B2 - Sublimation type heat transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention is used in combination with a thermal transfer sheet, and sublimates to heat-transfer the dye and / or pigment ink in the thermal transfer sheet to perform information-dependent recording. The present invention relates to a mold heat transfer sheet.

[Conventional technology]

The thermal transfer recording method is widely used as a recording method in printers such as computers and word processors.One of such thermal transfer recording methods is to use a thermal transfer layer containing a sublimable dye on the surface of a substrate such as polyethylene terephthalate in recent years. Attempts to record natural color photographic images and the like by superimposing recording of cyan, magenta, yellow, etc. by using a combination of the provided thermal transfer sheet and a heat transfer sheet having a dyeing property for the dye. For example, it is being used for directly recording an image on a CRT display.

As a heat transfer sheet used for such a recording method, a resin having high heat resistance such as polyethylene terephthalate or a porous paper-like layer made of a polypropylene-based resin laminated on both sides of a non-foamed polypropylene-based film is conventionally used. There is known a configuration in which a synthetic paper having a layer structure is used as a base material, and a receiving layer is provided on one side thereof.

[Problems to be solved by the invention]

However, the heat transfer sheet using polyethylene terephthalate or the like as a base material causes poor adhesion to a thermal head due to the high rigidity of the base material, resulting in a low density of a transferred image or white dots, and furthermore, a sheet in a transfer device. Feeding may not be performed smoothly,
As a result, there has been a defect that a printing shift occurs or a color shift occurs when printing is performed repeatedly, such as color printing, so that a transferred image with high definition cannot be obtained.

Further, in the case of a heat transfer sheet based on a polypropylene-based synthetic paper having a three-layer structure having a porous paper-like layer on both sides, the smoothness and cushioning property are poor, and the adhesion to the thermal head is poor, so that the dot of the heat transfer sheet is poor. There is a problem that white spots are likely to occur.

[Means for solving the problem]

The present invention has been made in view of the above points, and the sheet feeding in the transfer device is smoothly performed, the density is high,
It is an object of the present invention to provide a sublimation type heat transfer sheet capable of obtaining a clear transfer image without white dots.

That is, the present invention comprises a base material, and a receiving layer provided on one side of the base material for receiving a dye and / or a pigment ink sublimated and transferred from the thermal transfer sheet, and the base material is foamed. A sublimation type heat transfer sheet having a body structure and a smoothness of 1000 seconds or more.

The substrate in the sublimation-type heat transfer sheet of the present invention has a foam structure, and the foam structure referred to here is
It shows a structure in which countless fine bubbles are contained on the surface and inside thereof, and therefore has the feature that the cushioning property of the sublimation type heat transfer sheet is enhanced. Further, by containing the fine bubbles, the heat insulating property in the thickness direction of the base material is increased, and as a result, the sensitivity is increased. Further, in the present invention, a substrate having high smoothness and having a smoothness of 1000 seconds or more on the surface on which the receptor layer is formed is used.

Here, the term "smoothness" refers to the rate at which a certain surface comes into contact with a completely polished flat surface under a constant pressure by the speed of air leakage therebetween. The smoothness of paper is generally measured by Beck smoothness based on this method, but the smoothness in the present invention has a uniform correlation with Beck smoothness.
It was measured by Oken type smoothness meter.

In the present invention, the adhesion to the thermal head is improved by the cushioning property and the smoothness of the base material, so that a high print density and a clear transfer image without white dots can be obtained.

On the other hand, in the case of a polypropylene-based synthetic paper or the like in which a porous paper-like layer is laminated on both sides of a non-foamed base layer, the cushioning property is inferior to the base material used in the present invention due to the influence of the base layer, Because the smoothness of the surface is as low as 1000 seconds or less, the heat transfer sheet obtained using the synthetic paper as a base material has low adhesion with the thermal head, low print density and sharpness with white dots. Only images with low image quality can be obtained.

Further, even in the case of a substrate having a foamed structure, when the smoothness is 1000 seconds or less, particularly 500 seconds or less, white spots occur in the dots due to the influence of surface irregularities, and only an image with low definition is obtained.

The base material of the present invention may be subjected to a calendering treatment or the like, if necessary, to enhance the surface smoothness.

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows one embodiment of the sublimation type heat transfer sheet of the present invention, wherein 1 is a substrate, 2 is a receiving layer, and a substrate 1 and a receiving layer 2 are shown.
An intermediate layer 3 is provided as necessary, and a support 4 and, if necessary, a support 5 are provided on the surface of the substrate 1 on which the receiving layer is not formed.

In addition, the measurement of the smoothness was measured by the Oken type air permeability smoothness measuring device (KY-5 type manufactured by Asahi Seiko).

The substrate 1 has a foam structure as a whole. The foam structure is obtained by adding inorganic or organic fine particles to a thermoplastic resin and stretching it.At this time, a method of generating voids around the fine particles, mixing a high-molecular or low-molecular substance with poor compatibility with the thermoplastic resin Stretching, and generating voids using poor compatibility, extruding an organic solvent solution of synthetic resin from the orifice,
Then, the mixture is introduced into a coagulation bath to remove the solvent and solidify, and a method of generating voids by removing the solvent, a method of extruding and foaming the resin through an orifice together with a foaming agent, and the like. Those having a small diameter are particularly preferred.

As a material of the base material 1, polyester (for example, polyethylene terephthalate or the like), aliphatic polyamide (for example, 6
-Nylon and the like), aromatic polyamide, polycarbonate, polyacrylate, polyetherketone, polypropylene, polyethylene and the like, but are not limited thereto.

 The thickness of the substrate 1 is desirably about 30 to 200 μm.

As the material of the receiving layer 2, any material can be used as long as it is conventionally used for the receiving layer of this type of sublimation type heat transfer sheet. The synthetic resins (e) to (e) can be used alone or in combination of two or more.

(A) Those having an ester bond.

Polyester resin, polyacrylate resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl toluene acrylate resin.

(B) Those having a urethane bond.

 Polyurethane resin and the like.

(C) Those having an amide bond.

 Polyamide resin (nylon).

(D) Those having a urea bond.

 Urea resin and the like.

(E) Others having a highly polar bond.

Polycaprolactone resin, polystyrene resin, polyvinyl chloride resin, polyacrylonitrile resin, etc.

Alternatively, the receiving layer 2 comprises a saturated polyester and vinyl chloride /
It may be composed of a mixed resin with a vinyl acetate copolymer.

The vinyl chloride / vinyl acetate copolymer resin preferably has a vinyl chloride component content of 85 to 97% by weight and a degree of polymerization of about 200 to 800. Further, the copolymer may be a copolymer containing only a vinyl chloride / vinyl acetate copolymer component, but may contain a vinyl alcohol component, a maleic acid component and the like.

Further, styrene-acrylonitrile copolymer, styrene, maleic anhydride copolymer and the like, styrene-based copolymer,
It can also be composed of a PVC-acryl-styrene copolymer obtained by subjecting styrene to blast polymerization of a PVC-acryl block copolymer. If necessary, the receiving layer 2 may contain a releasing agent such as an ultraviolet absorber, an antioxidant, a plasticizer, and silicone oil. If necessary, a release agent layer made of silicone oil or the like may be provided on a part or the entire surface of the receiving layer 2. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon powder, fluorine-based and phosphate-based surfactants, and silicone oil. Silicone oil is preferred.

As the silicone oil, an oily oil can be used, but a curable oil is preferable. Examples of the curable silicone oil include a reaction curable type, a photocurable type, and a catalyst curable type, and a reactive curable type silicone oil is particularly desirable. As the reaction-curable silicone oil, it is also preferable to react and cure an amino-modified silicone oil and an epoxy-modified silicone oil. The addition amount of these curable silicone oils is preferably 0.5 to 30 parts by weight based on 100 parts by weight of the resin constituting the receiving layer.

When the release agent is dissolved or dispersed in an appropriate solvent and applied to part or all of the surface of the receiving layer, and then the release agent layer is provided by drying or the like, the release agent layer constituting the release agent layer is provided. As the mold agent, a reaction cured product of the above-mentioned amino-modified silicone oil and epoxy-modified silicone oil is particularly preferred. The thickness of the release agent layer is 0.01 to 5 μm, particularly 0.05 to 2 μm.
μm is preferred. The release agent layer may be provided on a part of the surface of the receiving layer, or may be provided on the entire surface, but when provided on a part of the surface of the receiving layer, the dot impact on the part where the release agent layer is not provided is provided. Recording, heat-sensitive melting transfer recording and recording with a pencil etc. can be performed, sublimation transfer recording is performed on the part where the release agent layer is provided, and recording by other recording method is performed on the part where the release agent layer is not provided , Etc., can be performed in combination with the sublimation transfer recording method and another recording method. When a release agent is contained in or on the thermal transfer layer of the thermal transfer sheet, the release layer may not be used for the receiving layer.

In the present invention, it is also possible to provide an intermediate layer between the substrate and the receiving layer.

The intermediate layer is mainly made of a resin having a 100% modulus specified in JIS-K-6301 of 100 kg / cm ² or less. Here, if the 100% modulus exceeds 100 kg / cm ² , the rigidity becomes hard. For this reason, even if the intermediate layer is formed using such a resin, sufficient adhesion between the thermal transfer sheet and the layer to be thermally transferred at the time of printing cannot be maintained. The lower limit of the 100% modulus is practically about 0.5 kg / cm ² . The intermediate layer may also serve as an adhesion improving layer between the substrate and the receiving layer.

Examples of the resin meeting the above conditions include the following. For example, it can be composed of a resin such as polyester, vinyl chloride-vinyl acetate copolymer, acrylic resin, polyvinyl acetate, polyurethane resin, and styrene copolymer. When the intermediate layer 3 is provided, the print density can be further increased by this cushioning property.

Further, in the present invention, for the purpose of improving the whiteness of the receiving layer to further enhance the clarity of the transferred image and imparting writability to the surface of the sublimation type heat transfer sheet, and preventing retransfer of the transferred image. A white pigment and / or a fluorescent brightener, a dye or the like may be added to at least one of the layers constituting the sublimation type heat transfer sheet such as a receptor layer, an intermediate layer, and a primer layer. By adding a white pigment, an image can be transferred with higher definition and excellent heat resistance and moisture resistance. Further, it is possible to prevent the white glossiness of the base material from being impaired by the color (yellowishness) peculiar to the resin due to the lamination of the resin such as the receiving layer and the cushion layer.

As the white pigment, titanium oxide, zinc oxide, kaolin clay and the like are used, and these can be used in combination of two or more. The addition amount of the white pigment is the receiving layer, the intermediate layer,
5 to 50 with respect to 100 parts by weight of the resin constituting the primer layer and the like
Parts by weight are preferred.

When the adhesion between the substrate and the receiving layer or the intermediate or the support is poor, it is preferable to apply a primer treatment or a corona discharge treatment to the surface.

The support 4 is provided as necessary to improve sheet feedability in a sheet transfer device. As the support 4, synthetic paper (polyolefin, polystyrene, etc.), woodfree paper, art paper, coated paper, Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, etc., cellulose fiber paper, polyolefin such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, Various plastic films or sheets such as polymethacrylate and polycarbonate can be used, and a white opaque film formed by adding a white pigment such as titanium white or a filler to these synthetic resins or a foamed foam sheet, etc. Can also be used without any particular limitation.

When the support 4 is made of a synthetic resin film, a white synthetic resin film, a foam sheet, or the like, the support 4 may be made of a resin of the same material as the substrate 1 or a resin of a different material. Particularly preferably, a cellulose fiber paper is used as the support 4. In this case, the thermal instability (e.g., expansion and contraction) of the plastic sheet having the foamed structure is compensated for by the cellulose fiber paper, and a high-sensitivity, good printed image with less roughness and white spots can be obtained. When a foamed plastic sheet is further used as the support 5 on the lower surface of the cellulose fiber paper, the front and back sides can be balanced, and a sublimation type heat transfer sheet with less thermal curl at the time of printing is preferably obtained.

When the support 4 is a natural paper such as art paper or coated paper, the moisture in the air is contained in the support 4,
Since the sublimation type heat transfer sheet including the base material and the receiving layer may be curled, the support 5 may be further provided for the purpose of preventing the curl.

If the support 4 or the support 5 is laminated so as to be releasable on the substrate 1, it is possible to improve sheet feedability in the transfer device at the time of transfer, and to use the sheet after peeling after transfer. It is possible. To laminate the support 4 on the substrate 1 so as to be releasable, either the two may be laminated with a weak adhesive, or a release treatment may be applied to the surface of the support, and a strong adhesive may be applied to the surface of the substrate 1 where the receptor layer is not formed. A method of applying and drying a heat-sensitive adhesive or the like and then bonding the same can be adopted. In the latter case, the base material 1 from which the support has been peeled off (an image has already been transferred to the receiving layer) is an adhesive. It can also be used as an attached label.

Further, a detection mark for positioning in a transfer device at the time of thermal transfer can be printed on the base material 1, the support 4 or the support 5.

Further, a slip layer made of, for example, an acrylate-based resin or a methacrylate-based resin is formed on the back surface of the base material 1 or the support 4 or the support 5 to improve the paper-passing property, or an antistatic property is provided by a surfactant or the like. Layers can be formed. The lubricating layer may include a lubricant.

The image receiving sheet of the present invention is a sublimation type heat transfer sheet capable of thermal transfer recording by appropriately selecting a base sheet, and an ID.
It can be applied to various uses such as cards such as cards, labels, stickers, postcards, and tags.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

In the following description, parts and percentages are by weight unless otherwise specified.

Example 1 A foamed polypropylene film (smoothness: 3140 seconds) (Toyobo Co., Ltd., Toyopearl SS, P4256) having a thickness of 50μ and a density of 0.65 g / cm ³ was used as a base material, and a receiving layer having the following composition was formed thereon. The composition for forming was applied with a Myr bar and dried (coating amount after drying: 6 g / m ² ) to form a receptor layer, and a sublimation type heat transfer sheet was obtained.

Receiving layer forming composition Polyester resin (Vylon 200: Toyobo) 70 parts by weight Polyester resin (Vylon 290: Toyobo) 30 parts by weight Amino-modified silicone (KF-393: Shin-Etsu Chemical Co., Ltd.) 5 parts by weight Epoxy-modified silicone ( X-22-343: Shin-Etsu Chemical Co., Ltd.) 5 parts by weight Methyl ethyl ketone 350 parts by weight Toluene 350 parts by weight A 4.5 μm thick polyester film (Lumirror: provided with a heat-resistant lubricating layer made of a thermosetting acrylic resin on one side.
Toray) is used as a substrate, and the coating amount after drying each of the ink compositions for forming a thermal transfer layer having the following composition on the surface opposite to the side on which the heat-resistant lubricating layer is provided becomes 1 g / m ^2. To obtain a thermal transfer sheet.

Cyan ink composition for thermal transfer layer formation Disperse dye (Kayaset Blue 714: manufactured by Nippon Kayaku) 5 parts Polyvinyl butyral resin (ESREC BX-1: manufactured by Sekisui Chemical) 4 parts Methyl ethyl ketone 46 parts Toluene 45 parts Magenta ink for thermal transfer layer formation Composition Disperse dye (MS Red G: manufactured by Mitsui Toatsu Chemicals) (Disperse Red 60) 2.6 parts Disperse dye (Macrolex Violet R: manufactured by Bayer) (Disperse Violet 26) 1.4 parts Polyvinyl butyral resin (Eslek BX-1: Sekisui Water) 4.3 parts Methyl ethyl ketone 45 parts Toluene 45 parts Yellow ink composition for thermal transfer layer formation Disperse dye (Macrolex Yellw 6G: Bayer) (Disperse Yellow 201) 5.5 parts Polyvinyl butyral resin (Eslek BX-1: Sekisui Chemical) 4.5 parts Methyl ethyl ketone 45 parts Toluene 45 parts This thermal transfer sheet was combined with the sublimation type heat transfer sheet. Used, color has a thermal head of a dot density 6 dots / mm video printer: VY-50 (manufactured by Hitachi, Ltd.)
After printing under the following conditions, the Macbeth color densitometer RD
When the reflection density of cyan was measured using -918, it was 1.95.
Met. In addition, the print density was uniform over the entire print surface, no missing dots were observed, the print density was high for all three colors, and a good transfer image was obtained without roughness, color misregistration of three colors, and uneven formation. . By changing the pulse width and controlling the electrical energy to be printed on the head,
An arbitrary print density was obtained with good reproducibility.

Printing conditions Printing speed: 33.3 ms / line feed pitch: 0.166 mm Pulse width: 12.0 ms Head applied voltage: 11.0 V Example 2 Polypropylene film having a foam structure (manufactured by Toray; Torayfan BOYP22, thickness 35 μ, smoothness 7590) Sec) as a base material, and the following composition for forming an intermediate layer was applied and dried with a miller bar (application amount after drying: 5 g / m ² ).

Composition for forming intermediate layer Polyester resin (Vylon 200: manufactured by Toyobo) 60 parts Polyester resin (Vylon 600: manufactured by Toyobo) 40 parts Solvent (methyl ethyl ketone / toluene = 1/1) 650 parts Then, the intermediate formed as described above A composition for forming a receiving layer having the following composition was applied on the layer with a Myar bar and dried (coating amount after drying: 5 g / m ² ) to form a receiving layer.

Receptive layer forming composition Polyester resin (manufactured by Toyobo: Byron 200) 70 parts Vinyl chloride-vinyl acetate copolymer (manufactured by Union Carbide: Vinylite VYHH) 30 parts Amino-modified silicone (manufactured by Shin-Etsu Chemical: KF-393) 7 parts Epoxy-modified silicone (Shin-Etsu Chemical: X-22-34)
3) 7 parts Solvent (methyl ethyl ketone / toluene = 1/1) 700 parts Further, an adhesive is applied to the non-receptive layer-formed surface of the substrate on which the receptive layer is formed (Fine-Tac SPS, manufactured by Dainippon Ink and Chemicals, Inc.)
-1002) and dried (applying about 20g /
m ² ), and affixed to a release treated surface of a commercially available release paper to obtain a sublimation type heat transfer sheet.

As a result of performing printing in the same manner as in Example 1 on this sublimation type heat transfer sheet, the image density was high, there were no white spots in the dots, and there was no color shift of three colors. This sheet peeled off the release paper and was suitable as a decorative label.

Example 3 A base material was formed of a polypropylene film having a foam structure (Toyopearl SS, P4256, manufactured by Toyobo Co., Ltd., thickness 50 μm,
A density of 0.65 g / cm ³ , a smoothness of 3140 seconds), a coated paper (New Top, Kanzaki Paper Co., Ltd., thickness: 60μ) as a first support on one side of the substrate, A polypropylene film having the same foam structure as the substrate was adhered as a second support on the opposite side of the substrate to the substrate. A sublimation type heat transfer sheet having a receiving layer provided on one side in the same manner as in Example 1 was printed in the same manner as in Example 1. As a result, the print density was high, white spots of dots, three-color shift, and print curl. Sublimation-type heat-transferable sheet having no sublimation.

Comparative Example 1 A non-foamed white polyethylene terephthalate film (thickness: 100μ, density: 1.42, smoothness: 643 seconds, Toray Industries, Inc.)
Except that the printing was performed on the sublimation-type heat-transferred sheet obtained in the same manner as in Example 1, except that the printing density was lower than that in Example 1. There were white spots in the dots of the toned image, and color shifts of three colors were also observed.

Comparative Example 2 Synthetic paper in which a porous paper-like layer made of a polypropylene-based resin was laminated on both sides of a non-foamed polypropylene film as a base material (manufactured by Oji Yuka Co., Ltd., YUPO FPG150, thickness 150μ, density 0.77g / cm ³ , smoothness 326 seconds) except that the printing was performed in the same manner as in Example 1 on the sublimation-type heat-transferred sheet obtained in the same manner as in Example 2. It was low, and white dots were observed in the dots of the halftone image.

Comparative Example 3 Synthetic paper having a base material laminated with expandable vinylidene chloride (manufactured by Kanzaki Paper Co., Ltd .; thickness 100 μ, density 0.86 g / cm ³ , smoothness 923)
(Seconds), except that the sublimation type heat transfer sheet provided with the receiving layer was printed in the same manner as in Example 1. As a result, the print density was low, and unclear transfer with white dots was observed. Only images were obtained.

Comparative Example 4 Sublimation type obtained in the same manner as in Example 2 except that the substrate was a polypropylene film having a foam structure (Toray; Torayfan BOYP56, thickness 35μ, smoothness 470 seconds (easy adhesion treated surface)). When printing was performed on the heat-transferred sheet in the same manner as in Example 1, as compared with Example 2, there were more white spots on the image surface, and in particular, the roughness of the low-density printing portion was severe.

〔The invention's effect〕

The sublimation-type heat transfer sheet of the present invention has a cushioning property and smoothness of the base material, so that the sheet feeding in the transfer device is smooth, the adhesion with the thermal head is improved, the printing density is high, and the whiteness of dots is further improved. This has the effect of obtaining a clear transfer image without omission.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Base material, 2 ... Reception layer, 3 ... Intermediate layer, 4 ... Support, 5 ... Support.

Claims (3)

(57) [Claims] 1. A heat-transferable sheet comprising a substrate and a receptor layer provided on one side of the substrate for receiving a dye and / or pigment ink which sublimates and migrates from the thermal transfer sheet. A sublimation type heat transfer sheet, characterized in that the material has a foam structure and that the smoothness of at least the receiving layer forming surface of the substrate is 1000 seconds or more. 2. The sublimation type heat transfer sheet according to claim 1, wherein at least one support is further laminated on the side of the substrate on which the receiving layer is not formed. 3. The sublimation type heat transfer sheet according to claim 1, wherein the substrate is made of polypropylene.