JPH04142985A - Image formation and composite thermal transfer sheet - Google Patents

Abstract

PURPOSE:To form a color image of high quality by solving the problem of the adhesion of a thermal transfer sheet and a receiving layer and preventing the transfer of a dye in the receiving layer by performing the transfer of the receiving layers corresponding to respective colors when dyes of a plurality of colors are printed and transferring the dye having a specific color to the specific receiving layer. CONSTITUTION:When dyes of a plurality of colors are printed, the transfer of the receiving layers corresponding to respective colors is performed and the dye of the specific color is transferred to the specific receiving layer. Prior to forming the receiving layers, it is pref. to form a release layer to the surface of a base material sheet. This release layer is formed from a release agent such as waxes. The dye receiving layer formed to the surface of the base material sheet receives the sublimable dyes transferred from a thermal transfer sheet after the receiving layers are transferred to an arbitrary transfer material. As a resin for forming the dye receiving layers, a vinyl type resin and a polyester resin are especially pref. As the pref. release agent used in the state mixed with the resin, silicone oil is desirable. The addition amount of the release agent is pref. 0.5-30 pts.wt. per 100 pts.wt. of the resin for forming the dye receiving layers.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an image forming method and a composite thermal transfer sheet 1 to
More specifically, the present invention relates to a method of forming high-quality color images by a thermal transfer method and a composite thermal transfer sheet used in the method.

(Prior art and its problems) Various thermal transfer methods have been known in the past, and among them, a dye is used as a recording agent and this is supported on a base sheet such as paper or plastic film. There have been proposed methods for forming various full-color images on a thermal transfer sheet, such as paper or plastic film, provided with a dye-receiving layer. In this case, the printer's thermal head is used as a heating means, and by extremely short heating, 3
Transferring a large number of color dots of one color or four colors to the transfer target A,
A full-color image of the document is reproduced using the multicolored dots.

The images formed in this way are very clear because the dye is used and have excellent transparency, so the images obtained have excellent intermediate color reproducibility and gradation, compared to conventional It is possible to form high-quality images that are similar to images produced by offset printing or gravure printing, and comparable to full-color photographic images.

However, the transfer materials on which images can be formed using the above method are limited to plastic sheets that can be dyed or paper that has a dye-receiving layer in advance, and images cannot be directly formed on general plain paper. The problem is that there is no. Of course, it is possible to form images on ordinary plain paper if a receptive layer is formed on its surface, but this is expensive for fishing on a boat, for example, for postcards, memos, stationery, etc. It is difficult to apply this method to general ready-made transfer materials such as report paper.

As a method to solve these problems, when an image is to be formed on a ready-made transfer material such as plain paper, a dye-receiving layer can be easily formed only in the necessary areas.
Receptive layer transfer sheets are known (for example, JP-A-62
(Refer to Publication No.-264994).

However, when the above-described receptor layer transfer sheet is used to transfer the receptor layer to a material to be transferred, and three or four color dyes are transferred to this receptor layer, the transferred receptor layer contains a release agent. It is included to prevent adhesion between the receiving layer and the thermal transfer sheet, but when dye transfer is performed 3 to 4 times to the same receiving layer,
There is a problem that there is a shortage of the above-mentioned mold release agent, and when the third or fourth color is transferred, the releasability is insufficient, and abnormal transfer occurs in which the dye layer of the thermal transfer sheet is transferred as an entire layer, resulting in a decrease in image quality. .

Another problem is that the receiving layer to be transferred is required to have good dyeability and also to have storage stability such that the transferred dye does not migrate in the receiving layer over time. The receptor layer-forming resin having the above properties differs depending on the type of dye to be transferred thereto, and therefore it is difficult to select a receptor layer-forming resin that has all the above characteristics for three or four color dyes. However, there is a problem in that some of the three or four colors cause blurring, resulting in insufficient image storage stability.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems,
An object of the present invention is to provide a method for forming high quality color images and a composite thermal transfer sheet for use in the method.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides a receptor layer transfer sheet in which a dye receptor layer is provided on one side of a base sheet, and a multi-color thermal transfer sheet or a multi-color thermal transfer sheet in which a sublimable dye layer is provided on one side of the base sheet. An image forming method characterized by preparing a thermal transfer sheet provided with a dye layer, and transferring only one color of dye to one transfer-receiving layer; A composite thermal transfer characterized in that a dye layer and a plurality of peelable dye-receiving layers are provided in plane order, and a receiving layer suitable for the dye of the dye layer is provided in front of the dye layer of each color. It is a sheet.

(Function) When printing dyes of multiple colors, transfer the receptor layer corresponding to each color, and transfer the dye of a specific color to a specific receptor layer, thereby preventing thermal transfer due to lack of release agent in the receptor layer. This solves the problem of adhesion between the sheet and the receptor layer, that is, the problem of abnormal transfer.At the same time, dyes of specific colors are transferred to specific receptor layers, thereby preventing dye migration within the receptor layer, resulting in high quality color images. is formed.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The image forming method of the present invention includes the following preferred embodiments.

First, in the first embodiment, one type of receptor layer transfer sheet and a plurality of color thermal transfer sheets provided with sublimable dye layers are used.

In the second embodiment, one type of receptor layer transfer sheet and one type of thermal transfer sheet in which dye layers of a plurality of colors are sequentially provided are used.

In the third embodiment, a plurality of receptor layer transfer sheets corresponding to the number of colors of a color image and a plurality of color thermal transfer sheets are used.

In the fourth embodiment, a plurality of receptor layer transfer sheets corresponding to the number of colors of a color image and one type of thermal transfer sheet in which dye layers of a plurality of colors are sequentially provided are used.

In a fifth embodiment, a composite thermal transfer sheet is used in which dye layers of a plurality of colors are provided on one type of base sheet and a dye receiving layer corresponding to the dye is provided in front of each color.

The second aspect will be described below as a representative example.

The receptor layer transfer sheet used in the second embodiment is one in which a dye receptor layer is releasably provided on one side of a base sheet.

As the base material sheet used, the same base material sheet used for conventional thermal transfer sheets can be used as is, and other materials can also be used.
There are no particular restrictions.

Specific examples of preferred base sheets include thin paper such as glassine paper, capacitor paper, and paraffin paper, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, and polyvinylidene chloride. , plastics such as ionomers, and base sheets made of composites of these and the above-mentioned paper.

The thickness of this base sheet can be changed as appropriate depending on the material so that its strength, heat resistance, etc. .

It is preferable to form a release layer on the surface of the base sheet prior to forming the receptor layer. Such a peeling layer is formed from a peeling FAIE agent such as wax, silicone wax, silicone resin, fluororesin, or acrylic resin. The formation method may be the same as the formation method of the receiving layer described later, and the thickness thereof is 0.5 to 5.
About 11m is sufficient.

If a matte receiving layer is desired after transfer, the surface can be made matte by incorporating various particles into the release layer or by using a base sheet whose surface on the release layer side has been matt treated. I can do it.

Of course, if the base sheet as described above has appropriate releasability, it is not necessary to form a release layer.

The dye-receiving layer formed on the surface of the above-mentioned base sheet is for receiving the sublimable dye that migrates from the thermal transfer sheet after transferring the receptor layer to an arbitrary transfer material and maintaining the formed image. It is.

Examples of the resin for forming the dye-receiving layer include polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylic ester,
Polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, ionomers, cellulose resins such as cellulose diacetate, polycarbonates Among them, vinyl resins and polyester resins are particularly preferred.

Preferred mold release agents to be mixed with the above resin include:
Examples include silicone oil, phosphate ester surfactants, fluorine surfactants, and silicone oil is preferred. The silicone oil includes epoxy modified silicone oil,
Modified silicone oils such as alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl polyether-modified, epoxy/polyether-modified, and polyether-modified silicone oils are desirable.

One or more types of mold release agents may be used. The amount of the release agent added is preferably 0.5 to 30 parts by weight per 100 parts by weight of the dye-receiving layer forming resin. If the addition amount does not fall within this range, problems such as fusion between the thermal transfer sheet and the dye-receiving layer or a decrease in printing sensitivity may occur. By adding such a release agent to the dye-receiving layer, the release agent bleeds out to the surface of the dye-receiving layer after transfer, forming a release layer.

The receiving layer is prepared by dissolving the above-mentioned resin with necessary additives such as a mold release agent on one side of the base sheet in an appropriate organic solvent or dispersing it in an organic solvent or water. The obtained dispersion can be processed, for example, by gravure printing method, screen printing method,
It is formed by coating and drying by a forming means such as a reverse roll coating method using a gravure plate.

When forming the dye-receiving layer, titanium oxide, zinc oxide,
Pigments and fillers such as kaolin clay, calcium carbonate, and finely powdered silica can be added.

The dye-receiving layer formed as described above may have any thickness, but the thickness for boat fishing is 1 to 50 μm. Although such a dye-receiving layer is preferably a continuous coating, it may also be formed as a discontinuous coating using a resin emulsion or resin dispersion.

Furthermore, an adhesive layer may be provided on the surface of the above-mentioned receptor layer in order to improve the transferability of these layers. These adhesive layers are made of, for example, polyamide resin, acrylic resin,
Vinyl chloride resin, vinyl chloride/vinyl acetate copolymer resin,
It is preferably formed to a thickness of about 0.5 to 10 μm by applying a solution of a resin such as polyester resin (having good adhesive properties when hot) and drying.

The material to which the receptor layer is transferred using the receptor layer transfer sheet as described above is not particularly limited, and examples include plain paper,
Any sheet such as high-quality paper, tracing paper, plastic film, etc. may be used, and the sheet may be of any shape such as cards, postcards, passports, stationery, report paper, notebooks, catalogs, etc. (especially those with rough surfaces). It can also be applied to plain paper and rough paper.

The receiving layer can be transferred using any heating method that can be heated to a temperature that activates the receiving layer or adhesive layer, such as a general printer equipped with a thermal head for thermal transfer, a hot stamper 1 heat roll for transfer foil, etc. A pressurizing means may also be used.

The thermal transfer sheet used in the second embodiment is formed by sequentially forming dye layers of yellow, magenta, cyan, and black if necessary on a base sheet in the same manner as in the prior art.

The base sheet of the thermal transfer sheet as described above is the same as the base sheet of the customer layer transfer sheet, and the dye layer formed on the surface of the base sheet is a layer in which dye is supported by an arbitrary binder resin. .

The dye to be used is not particularly limited, as any dye used in conventionally known thermal transfer sheets can be effectively used in the present invention. For example, some preferred dyes include MS Red G, Mac
rolex Red Violet R, CeresR
ed7B, Samaron Red HBSL, R
Examples of yellow dye include e5olin Red F3BS, and examples of yellow dye include Holon Brilliant Yellow 6GL.
, PTY-52, Macrolex Yellow 6G, etc., and as the blue dye, Kayaset Blue 1
4. Vaxolin Blue AP-FW, Holon Brilliant Blue S-R, MS Blue 100, etc. can be mentioned.

As the binder resin for supporting the above-described dye, any conventionally known binder resin can be used, and preferred examples include ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate,
Examples include cellulose resins such as cellulose acetate butyrate, vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinylpyrrolidone, and polyacrylamide, and polyesters. , butyral type, polyester type, etc. are preferable from the viewpoint of heat resistance, dye migration property, etc.

Furthermore, the dye layer may also contain various other conventionally known additives as required.

Preferably, such a dye layer is prepared by adding the above-mentioned sublimable dye, binder resin, and other optional components in a suitable solvent, dissolving or dispersing each component, and preparing a paint or ink for forming the dye layer. is formed by applying and drying the above-mentioned base material sheet in a surface-sequential manner.

The dye layer formed in this way has a thickness of about 0.2 to 5.0 μm, preferably about 0.4 to 2.07 zm, and
The sublimable dye in the dye layer is suitably present in an amount of 5 to 90% by weight, preferably 0 to 70% by weight of the dye layer.

Any means of thermal energy to be used when carrying out thermal transfer using the above-mentioned thermal transfer sheet and the above-mentioned transfer material (on which the receptor layer has been transferred) may be any conventionally known means, such as , by controlling the recording time using a recording device such as a thermal printer (e.g. Hitachi video printer vy-ioo).
A desired image is formed by applying thermal energy of approximately OmJ/mr+1'.

An important feature of the image forming method of the present invention is that only one color of dye is transferred to the receiving layer transferred by the receiving layer transfer sheet. That is, when forming a three-color image, for example, a yellow receptor layer is transferred and yellow dye is transferred thereto, and magenta and cyan are also transferred in the same manner. In this case, it goes without saying that the receptor layers may overlap each other. Therefore, according to such a method, the dye layer of the thermal transfer sheet does not come into contact with the same receptor layer multiple times, so there is no shortage of release agent in the receptor layer, and therefore abnormal transfer is prevented.

The first aspect is a case in which three types of thermal transfer sheets having different hues are used instead of a thermal transfer sheet in which dye layers are sequentially provided, and the same effects are obtained. Further, the third aspect and the fourth aspect are modifications of the fifth aspect described below, and have similar effects.

Next, a composite thermal transfer sheet of the present invention and an image forming method using the same will be explained based on a fifth embodiment.

The composite thermal transfer sheet of the present invention has a yellow receptor layer 21, a yellow dye layer 31, a magenta receptor layer 22, a magenta dye layer 3 on one side of a base sheet 1, as shown in the first figure.
2. A cyan receptor layer 23 and a cyan dye layer 33 (and a corresponding black receptor layer and black dye layer, if necessary) are provided.

Both the receptor layer and the dye layer may have the same structure as described above, but in the present invention, the yellow receptor layer is made of a resin for the receptor layer that has excellent yellow dye dyeing properties and storage stability (migration prevention properties). Similarly, the other receptor layers are formed by selecting a resin suitable for magenta or cyan dye.

When a color image is formed using the composite thermal transfer sheet of the present invention as described above, a yellow receptor layer is first transferred to a transfer material, and then a yellow dye is immediately transferred to the receptor layer. Thereafter, magenta and cyan are also transferred in the same manner. Therefore, according to this aspect, abnormal transfer is prevented as described above, and since the transferred dye of each color is transferred to the receiving layer suitable for each dye, the transferred dye is not absorbed in the receiving layer. Therefore, even if the color image is stored for a long period of time, problems such as blurring will not occur in the formed color image.

It should be noted that the third and fourth embodiments have similar effects, except that the structure of the receptor layer transfer sheet or thermal transfer sheet used is different.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 On the surface of a 25 μm thick polyester film (trade name "Lumirror", manufactured by Toshi ■), coating liquids A, B and C for the receptor layer having the following composition were coated with a bar coater at 6.0 g/dry time.
R + Do the same on each receptor layer and add 2g when dry.
/rrr coating and drying to form an adhesive layer,
A receptor layer transfer sheet used in the present invention was obtained.

Wind pipe γ/K 8-A; Polyester resin (Toyobo (made by Tsuru, Byron 103)
1.00 parts epoxy modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.)
3-part amino-modified silicone (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.)
3 parts methyl ethyl ketone/toluene (weight ratio 1/1) 500 parts Nail tube engineering S B; Vinyl chloride/vinyl acetate copolymer resin (1000A, manufactured by Denki Kagaku Kogyo ■) 100 parts Epoxy-modified silicone (KF-393, Shin-Etsu Chemical) (Industrial)
Tripartite amino-modified silicone (X
-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.)
3 parts methyl ethyl ketone/toluene (weight ratio 1/1) 500 parts Polyester resin (Erythyl XA7539, manufactured by Unitika) 100 parts Epoxy-modified silicone (KF-393, manufactured by Shin-Etsu Chemical)
Tripartite amino-modified silicone (X
-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.)
3 parts methyl ethyl ketone/toluene (
Weight ratio l/1) 500 parts Vinyl heat sealant (BLS-3082, manufactured by Toyo Ink Mfg. ■) 100 parts Ethyl acetate/toluene 400 parts Meanwhile, an ink for the dye layer having the following composition was prepared. , 6 with heat-resistant treatment on the back
It was coated and dried on a μm thick polyethylene terephthalate film with a wire bar so that the dry coating amount was 1.0 g/g, and silicone oil (X-41
A few drops of 4003A (manufactured by Shin-Etsu Silicone ■) were added using a dropper, and then spread over the entire surface to perform a back treatment coat to obtain a thermal transfer sheet used in the present invention.

Higashikatsu Okisato Enoyu Sarakai: Disperse dye (Kaya Set Blue 14, manufactured by Nippon Kayaku ■)
4.0 parts ethyl hydroxycellulose (manufactured by Vercules)
5.0 parts Methyl ethyl ketone/toluene (weight ratio 1/1) 80.0 parts Dioxane 10.0 parts Similarly, a yellow thermal transfer sheet was coated with a yellow disperse dye (M
acrolex Yellow 6G, manufactured by Bayer,
C, 1, Disperse Yellow 201)
and magenta thermal transfer sheet with magenta disperse dye (C,I).

Disperse Red60).

The above-mentioned receptor layer transfer sheet and plain paper are superimposed, and a thermal head is used to output IW/dot and pulse width 0.3.
~0.45 m5ec, with a dot density of 3 dots/mm, the yellow signal obtained by color separation of the original was printed, the receiving layer A was transferred in a pattern, and the surface of the receiving layer A was further printed. The yellow thermal transfer sheets were overlapped to form a yellow image under the same conditions. Furthermore, a receiving layer B and a magenta dye were similarly transferred to the image area obtained above using a magenta signal, and a receiving layer C and a cyan dye were further transferred using a similar cyan signal to form a full-color image.

Example 2 The receptor layers A, B, and C in Example 1 were made of polyester resin (Vylon 600, manufactured by Toyobo ■), Vylon 200, and vinyl acetate resin (Vylon C-2, manufactured by Block Chemical ■).
) was used to prepare a receptor layer thermal transfer sheet in the same manner as in Example 1, and in the same manner as in Example 1, receptor layer A was transferred and a yellow image was transferred thereon, and receptor layer B was transferred and a magenta image was transferred thereon. The image was transferred, and then the receiving layer C was transferred, and a cyan image was transferred thereon to form a full color image.

Example 3 In Example 1, the receiving layers A, B, and C were formed at intervals of 30 cm, and a yellow dye layer, a magenta dye layer, and a cyan dye layer were further formed in the arrangement shown in the first figure, and the composite of the present invention was prepared. A thermal transfer sheet was obtained.

A full color image was formed in the same manner as in Example 1 using this composite thermal transfer sheet.

Example 4 In Example 2, the receiving layers A, B, and C were formed at intervals of 30 cm, and a yellow dye layer, a magenta dye layer, and a cyan dye layer were further formed in the arrangement shown in the first figure, and the composite of the present invention was prepared. A thermal transfer sheet was obtained.

A full color image was formed in the same manner as in Example 1 using this composite thermal transfer sheet.

Comparative Example 1 Only the receptor layer A was formed in Example 1, the receptor layer A was transferred in the same manner as in Example 1, and yellow, magenta, and cyan images were formed on this receptor layer A to form a full color image. did.

Comparative Example 2 Only the receptor layer B was formed in Example 1, the receptor layer B was transferred in the same manner as in Example 1, and yellow, magenta, and cyan images were formed on this receptor layer B to form a full color image. did.

Comparative Example 3 Only the receptor layer C was formed in Example 1, the receptor layer C was transferred in the same manner as in Example 1, and yellow, magenta, and cyan images were formed on this receptor layer C to form a full color image. did.

The peelability between the thermal transfer sheet and the transfer material, the storage stability of each full-color image, etc. in the above Examples and Comparative Examples were evaluated, and the results shown in Table 1 below were obtained.

Table 1 Peelability Manual peeling ○: Good (no abnormal transfer) △: Slight adhesion (some abnormal transfer) ×: Part of the dye layer is transferred as is. (There are many abnormal transcriptions).

Preservability: Visual observation of the image after storage for 2 weeks at 60° C. ○: No bleeding △: Slight bleeding Overall evaluation: Macroscopic observation ○: Transfer operation, image clarity, and preservability were all good.

△: At least 1 of transfer operation, image clarity, and storage stability
One is defective.

(Effects) According to the present invention as described above, when printing dyes of multiple colors, a receiving layer corresponding to each color is transferred, and a dye of a specific color is transferred to a specific receiving layer, thereby The problem of adhesion between the thermal transfer sheet and the receptor layer due to lack of release agent in the receptor layer, that is, the problem of abnormal transfer, has been solved, and at the same time, the dye of a specific color can be transferred to a specific receptor layer, thereby preventing dye migration within the receptor layer. is prevented and high quality color images are formed.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically explaining the plane of the composite thermal transfer sheet of the present invention. Base films 21 to 23: Receiving layers 31 to 33: Dye layer and 1 other layer

Claims (3)

[Claims] (1) A receptor layer transfer sheet with a dye-receiving layer on one side of a base sheet, and a multi-color thermal transfer sheet with a sublimable dye layer on one side of the base sheet, or a multi-color dye layer 1. A method for forming an image, comprising: preparing a thermal transfer sheet provided with a heat transfer sheet, and transferring only one color of dye to one transfer-receiving layer. (2) A plurality of color dye layers and a plurality of removable dye-receiving layers are provided on one side of the base sheet in surface order, and in front of each color dye layer, a layer suitable for the dye of the dye layer is provided. A composite thermal transfer sheet characterized by being provided with a receptor layer. (3) The composite thermal transfer sheet according to claim 2, wherein the dye layer has at least three colors: yellow, cyan, and magenta.