JP2627739B2 - Heat transfer sheet and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-receiving sheet used in combination with a thermal transfer sheet and a method for producing the same.

[Conventional technology]

As the thermal transfer sheet, use is made of a polyethylene terephthalate film or the like having a surface provided with a thermal transfer layer composed of a sublimable dye and a binder. A thermal head that generates heat by being controlled by an electrical signal according to image information from the back side of the thermal transfer sheet, using both sheets as a receiving layer and superimposing both sheets so that the thermal transfer layer and the receiving layer are in contact with each other. Attempts have been made to form characters and images, especially natural color photographic images, by heating by a point-like heat-sensitive means such as described above and transferring the sublimable dye in the thermal transfer layer to the receptor layer.

However, when synthetic paper containing a resin having a low heat resistance such as a polyolefin resin as a resin component is used as a base material of the sheet to be heat-transferred, distortion is left on the synthetic paper due to heat generated by heating at the time of image formation. However, there is an inconvenience that the heat transfer sheet is curled.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat transfer sheet having a good finish with good flatness even after a photographic image or the like is formed, while suppressing curling of the heat transfer sheet after image formation.

[Means for Solving the Problems] The heat transfer sheet of the present invention is used in combination with a heat transfer sheet having a heat transfer layer composed of a sublimable dye and a binder, and dyes transferred from the heat transfer sheet during heating are used. A heat-receiving sheet, wherein a receiving layer for receiving is provided on one side of a substrate,
As a base material, a synthetic paper manufactured by adding a filler to a synthetic resin and mixing and extruding or a synthetic paper manufactured by coating an extender on the surface of a film, which is preliminarily subjected to a heat treatment, is used. The method for producing a heat transfer sheet of the present invention is characterized in that a filler is added to a synthetic resin, mixed, extruded, and an extender is added to the surface of a synthetic paper or film produced. The method is characterized by comprising a step of providing a receiving layer on a synthetic paper substrate manufactured by coating, and a step of performing a heat treatment on the synthetic paper substrate before this step.

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

FIGS. 1 to 5 show the structure of the heat transfer sheet of the present invention. The heat transfer sheet 1 has a receiving layer 3 provided on one surface of a synthetic paper base 2 as shown in FIG. . An intermediate layer 4 may be provided between the synthetic paper base 2 and the receiving layer 3 as shown in FIG. 2, or the surface of the synthetic paper base 2 on which the receiving layer 3 is not provided may be slippery. A layer 5 may be provided. Further, a lubricating layer 5 may be provided on the side of the synthetic paper base 2 where the receiving layer 3 is not provided (FIG. 3), or an antistatic layer 6 may be provided (FIG. 4). ). The intermediate layer 4, the lubricating layer 5, and the antistatic layer 6 are provided as needed, and may be provided as one, two, or three. FIG. 5 shows an example in which all three layers are provided.

 The materials constituting each layer will be described below in order.

(Synthetic paper base material) The base material 2 was manufactured by applying a filler to the surface of a synthetic paper or a film manufactured by adding a filler to a synthetic resin, mixing and extruding a preliminarily heat-treated synthetic resin. Synthetic paper is used. As synthetic paper, polyethylene resin,
Polyolefin resin such as polypropylene resin or other synthetic resin as a resin component, an inorganic filler or the like is added thereto, mixed and extruded (for example, Oji Yuka Synthetic Paper, YUPO), or polystyrene resin or Any of those produced by applying an extender to the surface of a film of a polypropylene resin or the like (for example, Nisshinbo Peach Coat) or the like is used, and is subjected to a heat treatment.

The conditions of the heat treatment differ depending on the thickness and the constituent components of the synthetic paper base material 2, that is, the type of the synthetic paper base material.
It is carried out by heating at a temperature of 140140 ° C., preferably 110 ° C. to 130 ° C., for a few seconds or longer.

When the heat treatment is performed in this manner, the shrinkage usually slightly occurs. However, even if the synthetic paper base material is thereafter heated by a thermal head or the like, there is almost no possibility that the synthetic paper base shrinks microscopically due to partial heat at the time of heating. Cause curling,
It is considered that unevenness does not occur.

The method of the heat treatment may be any method as long as the synthetic paper substrate 2 can remove the distortion generated at the time of production. However, if the synthetic paper substrate 2 receives heat in a completely free state, the flatness is rather lost. Heating in a state where free deformation of the synthetic paper base material 2 is prevented, such as heating between a pair of hot plates, biting around, or heating in a fixed state Is preferred. In order to prevent such free deformation and to continuously process the rolled synthetic paper substrate,
As shown in FIG. 6, it is preferable to use a heating drum 10 and wind it around the heating drum for heating. As the heating drum, either a steam heating type or an electric heating type can be used. Not only one heating drum but also two
The number may be four, four or more. When two or more heating drums are used, two or more heating drums may be used continuously or at intervals, and if they are used continuously, the effect of heating increases. Further, a step of cooling using a cooling drum after using the heating drum may be added.

The heat treatment is performed before the receiving layer 3 and other layers are provided, since the distortion of the synthetic paper substrate 2 only needs to be removed. Therefore, the timing at which the heat treatment may be performed depends on the synthetic paper substrate 2
When the receiving layer 3 is simply provided, it is performed before that, and when another layer is provided, it is before that.

Alternatively, for each of the above timings, 1
The fact that a plurality of heat treatments may be performed instead of one heat treatment may be apparent from the above description that a plurality of heating drums may be used continuously.

The side of the synthetic paper substrate 2 from which the heat treatment is performed is not necessarily limited. The heat treatment may be performed from either side of the synthetic paper base material 2 or may be performed separately or simultaneously from both sides.

In addition, when forming an image by superposing and heating the thermal transfer sheet, since it is easy to curl with the receiving layer side of the heat transfer sheet inside,
The heat treatment may be swirled from the side opposite to the side on which the receiving layer is provided so that the curling is somewhat curled with the receiving layer side outward. However, it is convenient to handle the heat transfer sheet with good flatness, and it is particularly convenient to stack the sheets and take them out one by one with a machine and convey them to the heating printing unit. It is preferable that there is no difference in the degree of heat treatment between the front and back of the material 2.

(Receiving Layer) The receiving layer 3 has a function of receiving a sublimable dye migrating from the thermal transfer sheet, and is specifically composed of the following synthetic resin.

(A) Those having an ester bond.

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

(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, styrene / maleic acid resin, polyvinyl chloride resin, polyacrylonitrile resin, etc.

In addition to the above synthetic resins, mixtures or copolymers thereof can also be used.

Alternatively, a receiving layer having the following sea-island structure, which is not simply constituted by using the above synthetic resin, can also be used.

For example, the first region of the receiving layer is formed of a synthetic resin having a glass transition temperature of -100 to 20 ° C, and the second region of the receiving layer is formed of a synthetic resin having a glass transition temperature of 40 ° C or more. And the second region are both exposed on the surface of the receiving layer 4 so that the first region is at least 15% of the surface and at the same time the first regions are formed independently of each other in the form of islands. Having a length of preferably 0.5 to 200 μm.

Any of the above-mentioned materials (a) to (e) and those having a sea-island structure may be further provided with an extender pigment such as silica, calcium carbonate, titanium oxide or zinc oxide, if necessary. Can be included.

The receiving layer 3 is kneaded with a synthetic resin constituting the layer and other components to be added as required to form a paint, and is coated with an air knife, a reverse roll,
It can be formed by applying by a coating method such as gravure coating or wire bar coating and drying.

(Intermediate Layer) The intermediate layer 4 is provided as necessary, and is provided by applying and drying a solution of an organic solvent such as a synthetic resin such as saturated polyester, polyurethane, or acrylate. The method of applying an organic solvent solution of these resins is reverse roll coating, gravure coating, wire bar coating, or the like, and the thickness of the coated film after drying is 3 to 10 μm.
It is.

Instead of the organic solvent solution of the synthetic resin, one or both of an aqueous solution of a water-soluble synthetic resin or an aqueous emulsion of a synthetic resin may be used. As a water-soluble synthetic resin,
Polyacrylamide, various resins containing a carboxyl group, for example, polyethylene, polyvinyl acetate, etc., and cellulosic resins can be used. As the synthetic resin aqueous emulsion, an aqueous emulsion of a synthetic resin such as polyacrylate, ethylene / vinyl acetate copolymer, polyurethane, and polyester can be used.

It is also possible to use a mixture of a water-soluble synthetic resin and an aqueous synthetic resin emulsion.

The coating method of the water-soluble resin or the aqueous emulsion may be an air knife coating method in addition to the above-mentioned coating method for forming the intermediate layer 4, and the thickness of the coated and dried film is 3 to
10 μm.

An extender pigment may be added to the intermediate layer 4 in order to improve the applicability of the paint at the time of application, the anti-blocking property of the coating film, and the concealing property. As the extender pigment, titanium oxide, zinc oxide, clay, Calcium carbonate or the like can be used. The extender pigment is preferably 30 parts by weight or less based on 100 parts by weight of the resin solid content of the intermediate layer.

(Slippery Layer) The slippery layer 5 is provided for facilitating removal of the heat transfer target sheet one by one, and may be made of various materials. Is that the surface of the slippery layer 5 is easily slipped between the surface of the receptor layer of the adjacent heat-transferable sheet, in other words, the coefficient of static friction is small.

The lubricating layer 5 is a coating film of a synthetic resin exemplified by a methacrylate resin such as a methyl methacrylate resin or a vinyl resin such as a corresponding acrylate resin or a vinyl chloride / vinyl acetate copolymer resin.

It was unexpected that these synthetic resin coating films were effective in taking out the heat transfer sheets one by one, and it was expected that simply providing an antistatic layer on the back surface of the substrate 2 would have the expected effect. Cannot be obtained.

The lubricating layer 5 can be formed by kneading a synthetic resin constituting the layer together with other components to be added as necessary and forming a coating, applying the same coating method as the receiving layer, and drying. , And its thickness is 1 to 10 μm.

(Antistatic Layer) The antistatic layer 6 is provided directly on the synthetic paper substrate 2 on the side where the receiving layer 3 is not provided, in contact with the synthetic paper substrate 2 or on the lubricating layer 5.
Is provided on the lower surface of the lubricating layer 5 (fourth illustration).

The antistatic layer 6 includes a surfactant, for example, a cationic surfactant (for example, a quaternary ammonium salt, a polyamine derivative or the like), an anionic surfactant (for example, alkyl phosphate or the like), a zwitterionic surfactant. It is constituted by applying an agent or a nonionic surfactant. It is preferable that the antistatic layer 6 is provided after the heat treatment, and if the heat treatment is performed after the antistatic layer 6 is provided, a trouble such as fusion with the heat treatment means may occur.

[Functions and effects of the invention]

In the heat transfer sheet of the present invention, since the synthetic paper base material is subjected to a heat treatment, the heat transfer sheet can be curled when forming a character or an image by heating together with the heat transfer sheet.

Further, according to the method for manufacturing a heat transfer sheet of the present invention, there is an advantage that a heat transfer sheet which is unlikely to curl when forming characters or images can be efficiently manufactured.

Example 1 Synthetic paper (Yupo EPG200, thickness 200μ) was used as a base sheet.
m, manufactured by Oji Oil Chemical Synthetic Paper Co., Ltd.), and heated by being brought into contact with the surface of a steel drum heated to 130 ° C. by electric heating for 10 seconds.
Then using the receptor layer forming composition having the following composition on a surface opposite to the heated surface, it is coated and dried using a wire bar, to provide a receiving amount of dry coating amount of 8 g / m ^2, the thermal transfer Sheet.

Receptive layer forming composition Polyester resin (Toyobo, Byron 200) 10 parts by weight Amino-modified silicone (Shin-Etsu Chemical, KF-393) 0.5 〃 Epoxy-modified silicone (Shin-Etsu Chemical, X-22-343) 0.5 溶 剤 Solvent 89 〃 (toluene / methyl ethyl ketone = 1/1) An antistatic agent (manufactured by Mitsubishi Yuka Fine,
ST-1000) / water / isopropyl alcohol = 7/3 diluted solution was applied (solid adhesion amount: about 0.3 g / m ² ) and dried.

By facing the thermal transfer layer of the thermal transfer sheet containing the sublimable dye in the thermal transfer layer to the receiving layer of the thermal transfer sheet obtained above, the highest image density is obtained by the thermal head from the back side of the thermal transfer sheet with the thermal transfer printer. To form an image. Curling of the heat transfer sheet on which an image was formed was hardly recognized.

Comparative Example A heat-receiving sheet was prepared in the same manner as in Example 1 except that the same synthetic paper as in Example 1 was used without heat treatment, and an image was formed as in Example 1. The image receiving paper on which the image was formed had a large curl.

Example 2 Synthetic paper (Peachcoat WP-110, manufactured by Nisshinbo, PP base) was used as a substrate, and heated by being brought into contact with the surface of a steel drum heated to 130 ° C. for 5 seconds. Using the composition for forming an intermediate layer having the following composition on the side opposite to the heated side, apply and dry using a wire bar, and apply 10 g /
and an intermediate layer of m ^2.

Intermediate layer forming composition Polyester resin 10 parts by weight (manufactured by Toyobo Co., Ltd., Byron 200) Methyl ethyl ketone 70 の 上 On the above-mentioned intermediate layer, by using a receiving layer forming composition having the following composition, by a reverse roll coating method using a gravure roll. Coating and drying were performed, and a receiving layer having a coating amount of 5 g / m ² upon drying was provided.

Receptive layer composition Polyester resin 7 parts by weight (Toyobo Co., Ltd., Byron 200) Vinyl chloride-vinyl acetate copolymer resin 3 (UCC, Vinylite VYHH) Amino-modified silicone 0.5 (Shin-Etsu Chemical, KF-393) Epoxy-modified Silicone 0.5 〃 (Shin-Etsu Chemical, X-22-343) Solvent (toluene / methyl ethyl ketone = 1/1) 89 後 After the receiving layer is formed, the surface on which the receiving layer is not formed is heated at 115 ° C. for 10 Heated for seconds. After heating, the anti-static agent (Analytical Chemical Laboratory of Skokie, USA,
Using a 1% isopropanol solution of Statiside), the composition was coated and dried so that the coating amount at the time of drying was 8 g / m ² , to obtain a heat transfer sheet.

An image was formed on the receiving layer of the heat transfer sheet in the same manner as in Example 1. Curling of the heat transfer sheet on which an image was formed was hardly recognized.

Comparative Example In Example 2, neither the heat treatment of the synthetic paper base material itself nor the heat treatment after the provision of the receiving layer was performed, and the other steps were the same as in Example 2 to form an image on the receiving layer of the heat-receiving sheet. But Carl was remarkable.

[Brief description of the drawings]

1 to 5 are cross-sectional views showing the structure of the heat transfer sheet of the present invention, and FIG. 6 is a view showing an example of the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1 ... Heat transfer sheet 2 ... Synthetic paper base material 3 ... Reception layer 4 ... Intermediate layer 5 ... Slip layer 6 ... Antistatic layer 10 ... Heating drum

Claims (13)

(57) [Claims] (1) a heat transfer sheet having a heat transfer layer comprising a sublimable dye and a binder;
A heat transfer sheet in which a receiving layer for receiving a dye migrating from the heat transfer sheet at the time of heating is provided on one surface of a substrate, and a filler is added to a synthetic resin that has been subjected to heat treatment in advance as a substrate. A heat-transferable sheet, characterized by using synthetic paper produced by mixing, extruding, and / or extruding a body pigment onto the surface of a film. 2. The heat-transferable sheet according to claim 1, wherein the heat-treated surface is a surface opposite to the surface on which the receiving layer is provided. 3. The heat transfer sheet according to claim 1, wherein an intermediate layer is provided between the receiving layer and the synthetic paper base. 4. The heat-transferable sheet according to claim 1, wherein a slip layer is provided on the side of the synthetic paper base where no receiving layer is provided. 5. The method according to claim 1, wherein an antistatic layer is provided on the side of the synthetic paper base where the receiving layer is not provided.
Item 6. The heat transfer sheet according to any one of the above items. 6. A step of providing a receiving layer on a synthetic paper or a synthetic paper base material produced by applying an extender to the surface of a synthetic paper or film produced by adding a filler to a synthetic resin, mixing and extruding; A step of subjecting the synthetic paper base material to a heat treatment before the step (c). 7. The method according to claim 1, wherein two steps of a step of providing an intermediate layer and a step of providing a receiving layer on the synthetic paper base material are sequentially performed, and the synthetic paper base material is subjected to a heat treatment before the two steps. 7. The method for producing a heat-transferable sheet according to item 6. 8. A synthetic paper base material comprising: a step of providing an intermediate layer on one side of a synthetic paper base; a step of providing a receiving layer; and a step of providing a slipping layer on the other side of the synthetic paper base. 8. The method according to claim 7, further comprising the step of: performing the step of providing a heat treatment after the step of providing the intermediate layer; and performing the heat treatment before the three steps. . 9. The method for producing a heat transfer sheet according to claim 6, wherein the heat treatment is performed from the side of the synthetic paper substrate opposite to the side on which the receiving layer is provided. . 10. The method according to claim 6, wherein the heat treatment is performed a plurality of times. 11. The method according to claim 6, wherein the heat treatment is performed by contact with a heating drum. 12. The method according to claim 11, wherein the heat treatment is performed by contacting a plurality of continuous heat drums. 13. The method for producing a heat-transferable sheet according to claim 6, wherein an antistatic layer is provided after the heat treatment.