JP3263765B2 - Thermal transfer image forming method and thermal transfer image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image forming method and, more particularly, to a thermal transfer image forming method using a transfer sheet and an image receiving sheet having a receiving layer formed so as to be releasable.

[0002]

2. Description of the Related Art Conventionally, various thermal transfer image forming methods are known. Among them, a hot-melt ink layer containing a pigment or the like is supported on a base sheet such as paper or a plastic film, and is subjected to a hot-melt method. A method has been proposed in which an ink transfer sheet is used to transfer an image onto a transfer target such as paper or plastic.

Instead of this hot-melt ink layer, a dye layer containing a sublimable dye is carried on a base sheet to form a dye transfer sheet, and various types of paper are provided on a transfer member such as paper or plastic provided with a dye receiving layer. A method of forming a full-color image has been proposed.

In these methods, a thermal head of a printer is used as a heating means, and three or four color dots are transferred to a transfer target by heating for a very short time, and the multicolor dots are used for character printing. It reproduces a full-color image with a resolution comparable to that of a photo.

[0005] Among these images, particularly, an image obtained by transferring a dye is used because a coloring agent used is a dye.
Extremely clear and excellent in transparency, the resulting image is excellent in intermediate color reproducibility and gradation, similar to images by conventional offset printing and gravure printing, and has a high image quality comparable to full-color photographic images. A quality image can be formed.

In order to prevent the image quality from being affected by the surface irregularities and formation of the transfer-receiving member, first, an image is formed on a receiving layer of an image receiving sheet provided with a releasable receiving layer. After that, a method has been proposed in which an image receiving sheet is heated to transfer a receiving layer on which an image is formed onto a transfer receiving body.

[0007]

Conventionally, when the transferable receiving layer after image formation is transferred to a transfer-receiving member, an arbitrary area is solidly transferred. However, in this method, an image is formed. Unacceptable portions of the receiving layer, for example, portions of the receiving layer between characters, are also transferred. The receiving layer after transfer acts as a protective layer for protecting the image, and this protective layer has high robustness,
Although it is suitable for protecting images, on the other hand, writing on the obtained prints was impossible because of poor writing performance with respect to pencils, ballpoint pens and the like.

In particular, when a dye transfer sheet is used, the sublimation transfer image formed by the thermal head is insufficiently heated due to the influence of adjacent dots that do not generate heat, and the outline of the image becomes unclear. Tends to be prone. In particular, the tendency is remarkable in the outline portion of the character.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image-formed product having high robustness, excellent writability, and good reproducibility.

[0010]

In order to achieve the above object, the present invention provides a transfer sheet comprising a base sheet and a dye layer or a hot-melt ink layer formed on one surface of the base sheet. And an image receiving sheet including a base sheet and a receiving layer formed releasably on one surface of the base sheet so that the dye layer or the heat-meltable ink layer and the receiving layer are in contact with each other. Together, transferring thermal dye to the dye or hot-melt ink on the receiving layer by applying thermal energy,
Then, in the thermal transfer image forming method of applying the thermal energy from the base sheet side of the image receiving sheet to transfer the receiving layer to the transfer object, the heating data at the time of receiving layer transfer is heating data according to image information. Oh is, the field at the time of the receiving layer transfer
The receiving layer of only the image portion is transferred to the transfer object, and
The outer receiving layer is not transferred to the transfer object,
A dye transfer area and a receptor layer transfer area for transferring to a transfer target
Is characterized in that the difference in size is 1 to 2 dots .

Further, the present invention is characterized in that the dye transfer area transferred based on the heating data at the time of dye transfer has a character shape.

[0012]

The printed matter formed by the above-mentioned thermal transfer image forming method is excellent in abrasion and solvent properties, and has a writing property since the receiving layer is not transferred to portions other than the image portion. Further, by forming the dye transfer area larger than the receiving layer transfer area, it is possible to obtain an image having a sharp contour similar to that in the case of using the hot-melt ink transfer sheet. In addition, by transferring the receiving layer in a region slightly larger than the dye transfer region, the edge of the formed image can be reliably transferred.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal transfer image forming method of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of a case where a dye transfer sheet is used in the thermal transfer image forming method of the present invention. In FIG. 1, a dye transfer sheet 11 includes a base sheet 12 and a dye layer 13 formed on one surface of the base sheet 12, and a dye image receiving sheet 21 includes a base sheet 22 and a base sheet 22. Is provided with a dye receiving layer 23 formed releasably on one surface. The dye receiving sheet 21 is pressed in the direction of the dye transfer sheet 21 by the platen roller 41 from the base sheet 22 side, and the dye transfer sheet 11 is pressed so that the dye layer 13 and the dye receiving layer 23 are in contact with each other.
And the dye image receiving sheet 21 are overlapped. A thermal head 51 is in contact with the base material sheet 12 side of the dye transfer sheet 11, and the thermal head 51
Is disposed at a position facing the platen roller 41.

As the dye transfer sheet or the heat-meltable ink transfer sheet 11 which can be used in the thermal transfer image forming method of the present invention, various known transfer sheets can be used. Specifically, as the base sheet 12 of the transfer sheet 11, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluorine resin, chloride resin Examples include rubber, plastic films such as ionomers, papers such as condenser paper and paraffin paper, and nonwoven fabrics, and composites thereof.

The thickness of the base sheet 12 can be appropriately determined in consideration of the required strength, thermal conductivity and the like, and is usually preferably about 2 to 10 μm.

The dye layer 13 of the dye transfer sheet 12 is a layer in which a dye is carried by an optional binder resin. Examples of the dye to be used include those used in conventionally known dye transfer sheets. Specifically, as a red dye, MS Red G, Macrol ex R
ed Violet R, Ceres Red 7B,
Samaron Red HBSL, Resolin
Red F3BS, etc., and as a yellow dye, Holon Brilliant Yellow 6GL, PTY-5
2, Macrolex Yellow 6G, etc., and as the blue dye, Kayaset Blue 714, Waxolin Blue AP-FW, Holon Brilliant Blue SR,
MS Blue 100 and the like.

Examples of the binder for supporting the above-mentioned dye include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral. , Polyvinyl acetal,
Examples include vinyl resins such as polyvinylpyrrolidone and polyacrylamide, and polyesters. Among the above resins, cellulose-based, acetal-based, butyral-based, and polyester-based resins are preferred from the viewpoints of heat resistance, dye migration, and the like.

The dye layer 13 may contain various additives as necessary. The thickness of the dye layer 13 is about 0.2 to 5 μm, preferably about 0.4 to 2 μm, and the dye layer 13 contains 5 to 90% by weight, preferably 10 to 70% by weight of a sublimable dye. It is preferable to be contained.

When a hot-melt ink transfer sheet is used as the transfer sheet, the ink layer may be composed of a colorant and a vehicle, and may further contain various additives as necessary. As the colorant, an organic or inorganic pigment is preferable, and the concentration is preferably in the range of 5 to 20% by weight. As a vehicle, wax or resin as a main component, other drying oil, mineral oil, cellulose and natural rubber,
A mixture with a rubber derivative such as isoprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, butyl rubber, chloroprene rubber, and acrylic rubber is used. Representative examples of the wax include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, whale wax,
Various waxes such as Ibota wax, wool fat, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide, caddylin wax, rice wax, montan wax and the like are used. Representative examples of the resin include acrylic, polyethylene, polyester, polyamide, nylon, methacrylic resin, styrene resin, vinyl chloride resin, vinylidene chloride resin, novolak resin, olefin resin, polyacetal resin, vinyl acetate resin, petroleum resin, and the like. .

The thickness of the ink layer should be determined so as to balance the required density with the thermal sensitivity.
The range of m is preferred.

On the other hand, as the base sheet 22 of the dye receiving sheet 21 used in the thermal transfer image forming method of the present invention, the same sheets as the various sheets mentioned as the base sheet 12 of the dye transfer sheet 11 described above are used. In particular, polyester resin sheets having high heat resistance such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ether ketone, and polyether sulfone are preferred. The thickness of the base sheet 22 of the dye receiving sheet 21 is
The strength, heat resistance and the like can be appropriately determined depending on the material so as to be appropriate, and usually about 1 to 10 μm is preferable.

The dye receiving layer 23 of the dye receiving sheet 21 is
This is for receiving the sublimable dye or hot melt ink transferred from the dye layer 13 of the dye transfer sheet 11 and maintaining the formed image. Examples of the resin for forming such a 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, and polyethylene terephthalate. Polyester resins such as 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 and the like. In particular, a vinyl resin and a polyester resin are preferable, and a composite thereof may be used.

The dye receiving layer 23 preferably contains a release agent together with the above resin in order to prevent the dye transfer sheet 11 from being fused to the dye layer 13. Examples of the release agent to be used include silicone oil, phosphate ester type surfactant, fluorine type surfactant and the like, and silicone oil is particularly preferable. As the silicone oil, a modified silicone oil such as an epoxy-modified, an alkyl-modified, an amino-modified, a carboxyl-modified, an alcohol-modified, a fluorine-modified, an alkyl aralkyl-polyether-modified, an epoxy / polyether-modified, or a polyether-modified is preferable.

One or two types of the above-mentioned release agents are used.
The range is preferably 0.5 to 30 parts by weight based on 99 parts by weight.

Next, as shown in FIG. 2, the dye receiving sheet 31 on which the image is formed is superimposed on the transfer material, and the receiving layer is transferred to the transfer material by heating from the dye receiving sheet 31 side. The dye image-receiving sheet 21 used in this thermal transfer image forming method may have a release layer between the base sheet and the dye-receiving layer. This release layer is formed from a release agent such as waxes, silicone wax, silicone resin, fluororesin, and acrylic resin. When it is desired that the image transferred and formed on the transfer receiving body 61 is matte, a base sheet in which various particles are contained in the release layer or the surface on the release layer formation side is matted is used. Should be used. When the base sheet of the dye receiving sheet has an appropriate release property, the release layer is unnecessary.

In the present invention, since the data according to the image information is used as the heating data at the time of transfer of the receptor layer, the receptor layer transferred onto the material to be transferred has substantially the same shape as the image. In the normal method, when the receiving layer on which an image is formed is transferred to a material to be transferred, heating is performed on the entire area on which the image is formed, and the transfer is performed (the area surrounded by the dotted line in FIG. 3). However, in this conventional method, a receiving layer between characters is also transferred. The receiving layer after transfer acts as a protective layer for protecting the image, and this protective layer is also robust and suitable for protecting the image, but has a low writability, so that a pencil or a ballpoint pen is placed on the obtained print. It was not possible to write using it. In the present application, since the receiving layer is transferred only to the image portion 34, it is possible to write the portion around the image.

As the heating data at the time of transfer of the receptor layer, data corresponding to the heating data at the time of image formation for transferring the dye or the hot-melt ink onto the receptor layer of the image receiving sheet is used. When the same data as the heating data at the time of image formation is used as the heating data at the time of transfer of the receiving layer, the information processing is simple and a complicated data processing circuit is not required.

In particular, in an image formed using a dye transfer sheet, the heat generation of the dots in the image outline becomes insufficient due to the influence of the adjacent dots that do not generate heat, and the outline tends to be unclear. In particular, the tendency was remarkable in the outline portion of the character. In this case, an image with a clear contour can be obtained by making the transfer area of the dye larger than the image area to be obtained, and transferring only the image area originally desired at the time of transfer of the receptor layer. At this time, the dye transfer area is set to be at least about 1 to 2 dots wider than the originally obtained image area .

Further, when an image or the like having gradation is formed by using a dye transfer sheet, the transfer of the dye is delicate at the outline of the image.
Heating needs to be performed in a range that is 1 to 2 dots wider than the image portion.

Since the obtained thermal transfer image was transferred together with the receiving layer, an image having high robustness and excellent storage stability was obtained. Further, since only the image portion is transferred, it is possible to write with a pencil or the like between the images.

[0031]

According to the present invention, it is possible to provide a heat-transferred image having both writability and durability. In particular, in the dye transfer method, the contour portion can be accurately formed.

[Brief description of the drawings]

FIG. 1 is a diagram when an image is formed on a dye receiving sheet.

FIG. 2 is a diagram when a dye image receiving sheet on which an image is formed is transferred to a transfer material.

FIG. 3 is a diagram illustrating a dye image receiving sheet on which an image is formed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 Dye transfer sheet 12 Base sheet 13 Dye layer 21 Dye image receiving sheet 22 Base sheet 23 Dye receiving layer 31 Thermal transfer image receiving sheet on which image is formed 32 Base sheet 33 Dye receiving layer on which image is formed 34 Image portion 41 Platen Roller 51 Thermal head 61 Transfer material

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Satoru Kawai 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (56) References JP-A-4-131277 (JP, A) JP-A-4-327981 (JP, A) JP-A-2-200451 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/325 B41M 5/26

Claims (4)

(57) [Claims] 1. A transfer sheet comprising a base sheet and a dye layer or a hot-melt ink layer formed on one surface of the base sheet, and a transfer sheet capable of being peeled off on one surface of the base sheet and the base sheet. An image receiving sheet having a receiving layer formed on the receiving layer is overlapped so that the dye layer or the hot-melt ink layer and the receiving layer are in contact with each other, and heat energy is applied to apply the dye or the hot-melt Transfer method, and thereafter, applying thermal energy from the base sheet side of the image receiving sheet to transfer the receiving layer to a transfer receiving body. Oh the heating data corresponding to is, the image upon receiving layer transfer
Part of the receiving layer is transferred to the transfer object, and
Is not transferred to the transfer receiving body, and
Material transfer area and the receiving layer transfer area to be transferred to the object to be transferred.
A thermal transfer image forming method, wherein the difference in size is 1 to 2 dots . 2. The thermal transfer image forming method according to claim 1, wherein the dye transfer area is larger than the receiving layer transfer area. 3. The thermal transfer image forming method according to claim 1, wherein the dye transfer area is smaller than the receiving layer transfer area. 4. The thermal transfer image forming method according to claim 1, wherein the heating data at the time of transfer of the receiving layer is in the form of characters.