JPH0313388A - Thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer image receiving sheet excellent in the curl preventing properties and slip properties within a printer, generating no printing trouble and capable of forming an image of high image quality by forming the curl preventing layer formed to the rear of a base sheet from a filler-containing resin low in a degree of heat shrinkage. CONSTITUTION:A thermal transfer image receiving sheet consists of a base sheet, the dye receiving layer formed to the surface of the base sheet and the slippery curl preventing layer formed to the rear of the base sheet. The slippery curl preventing layer has function preventing the curl of the thermal transfer image receiving sheet due to the heat of a thermal head and lowering the coefficient of friction with the dye receiving layer in a lapped state to enhance slip characteristics and is formed from a resin low in a degree of heat shrinkage and a filler. As a pref. example of the resin low in a degree of heat shrinkage, one having a degree of heat shrinkage of -1.0-1.5% and softening temp. of 90 deg.C or more is used. As the filler to be used, a particle having high heat resistance is especially pref. and the pref. particle size thereof is about 0.5-30mum.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a thermal transfer image-receiving sheet, and more specifically, it can be used in a printer with excellent curl prevention properties and slip properties (transportability), without printing troubles, and with high image quality. The purpose of the present invention is to provide a thermal transfer image-receiving sheet on which images can be formed.

(Prior art and its problems) Conventionally, various thermal transfer methods are known, but among them, a thermal transfer sheet is produced by using a sublimable dye as a recording agent and supporting it on a base sheet such as paper or a plastic sheet. There have been proposed methods for forming various full-color images on a thermal transfer image-receiving sheet that can be dyed with a sublimable dye, such as a thermal transfer image-receiving sheet in which a dye-receiving layer is provided on the surface of paper or plastic film.

In this case, the printer's thermal head is used as a heating means, and by heating in an extremely short time, three or four colors can be printed.
A large number of colored dots are transferred to a thermal transfer image-receiving sheet, and a full-color image of an original is reproduced using the multicolored colored dots.

The images formed in this way are very clear because the coloring material used is dye, and they have excellent transparency, so the images obtained have excellent intermediate color reproducibility and gradation, and are 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.

Thermal transfer image-receiving sheets used in the above-mentioned sublimation type thermal transfer method are made by dye dyeing on the surface of an opaque base sheet such as paper or synthetic paper when a reflective image is required, such as for general printed matter or photographs. A dye-receiving layer made of a resin with good adhesion is used.On the other hand, when a translucent image is required, such as when used in an OHP (overhead projector), etc.

A dye-receiving layer provided on a transparent base sheet such as a polyester film is used.

In any case, when forming images using these thermal transfer image-receiving sheets, the surface of the thermal transfer image-receiving sheet is heated during transfer, resulting in curling of the thermal transfer image-receiving sheet, and There is a problem in that the slip property of the thermal transfer image-receiving sheet deteriorates, causing troubles such as paper jams. In addition, since the entire printer is inevitably heated to a certain temperature, curling occurs within the printer even before printing, which worsens the conveyance of the thermal transfer image-receiving sheet and causes problems such as double feeding. Occur.

Furthermore, in the case of forming a multi-color image, printing is performed three to four times on the same image-receiving sheet, resulting in even more severe curling.
Misalignment of printed dots occurs and image quality deteriorates, especially in OH
In the case of P-translucent images, the print image is projected and enlarged several times, so that the image quality deteriorates more markedly.

The present inventor has previously proposed forming an anti-curl layer on the back surface of a thermal transfer image-receiving sheet from a resin with low heat-stretchability as a method of solving the above-mentioned curling problem, and has obtained an excellent effect. .

However, when the thermal transfer image-receiving sheet provided with the above-mentioned curl prevention layer is stacked and set in the paper feed unit of a printer, the curl prevention layer of the upper thermal transfer image-receiving sheet and the thermal transfer image-receiving sheet below it overlap. The coefficient of friction with the dye-receiving layer is large, causing the problem of double feeding. Such problems can be prevented by attaching a pressure-sensitive adhesive sheet having excellent slip properties to the curl prevention layer each time, but such a method has the problem of being extremely complicated.

Therefore, an object of the present invention is to provide a thermal transfer image-receiving sheet that has excellent curl prevention properties and slip properties in a printer, is free from printing troubles, and is capable of forming high-quality images.

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

That is, the present invention comprises a base sheet, a dye-receiving layer formed on the surface of the base sheet, and an anti-curl layer formed on the back surface of the base sheet, and the anti-curl layer contains a filler and has a heat expansion/contraction rate. This is a thermal transfer image-receiving sheet characterized in that it is formed from a resin with a small .

(Function) By forming the anti-curl layer of the thermal transfer image-receiving sheet from a resin containing a filler with a low thermal expansion/contraction rate, it has excellent anti-curl and slip properties in the printer, and produces high-quality images without printing problems. A thermal transfer image-receiving sheet that can be formed is provided.

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

The thermal transfer image-receiving sheet of the present invention comprises a base sheet, a dye-receiving layer formed on the surface of the base sheet, and a slip-curling prevention layer formed on the back surface of the base sheet.

The base sheet used in the present invention includes synthetic paper (polyolefin type, polystyrene type, etc.), high quality paper, art paper,
Coated paper, cast coated paper, wallpaper, lined paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internalized paper, paperboard, etc., cellulose fiber paper, polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polyester Various plastic films or sheets such as methacrylate and polycarbonate can be used, and white opaque films formed by adding white pigments and fillers to these synthetic resins or foamed foam sheets can also be used, but there are no particular limitations. Not done. Furthermore, a laminate made of any combination of the above-mentioned base sheets can also be used. Typical examples of laminates include cellulose fiber paper and synthetic paper, or synthetic paper of cellulose fiber paper and plastic film or sheet. The thickness of these base sheets may be arbitrary, and typically has a thickness of about 10 to 300 LLm, for example. Furthermore, in the case of a plastic film, a plasticizer or the like may be added to adjust the rigidity of the film.

Particularly in applications requiring a translucent image for OHP, a transparent polyethylene terephthalate film having a thickness of about 50 to 200 μm is suitable.

When the base sheet as described above has poor adhesion to the dye-receiving layer formed on the surface thereof, it is preferable to subject the surface thereof to a brimer treatment or a corona discharge treatment.

The dye-receiving layer formed on the surface of the base sheet is for receiving the sublimable dye transferred from the thermal transfer sheet and maintaining the formed image.

Examples of the binder resin for forming the dye-receiving layer include polyolefin resins such as polypropylene, halogenated vinyl resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins 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.

The dye-receiving layer in the thermal transfer image-receiving sheet of the present invention is prepared by adding necessary additives such as an antioxidant and an ultraviolet absorber to the binder resin as described above on at least one side of the base sheet. For example, a dispersion in which is dissolved in a suitable organic solvent or dispersed in an organic solvent or water, for example,
It is formed by coating and drying using a forming method such as a gravure printing method, a screen printing method, or a reverse roll coating method using a gravure plate.

The dye-receiving layer preferably contains a release agent in order to provide good release properties from the thermal transfer sheet. Preferred mold release agents include silicone oil, phosphate ester surfactants, fluorine surfactants, and silicone oil is preferred. The above silicone oils include epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl polyether-modified, epoxy/polyether-modified,
Modified silicone oil such as polyether modified silicone oil is desirable.

One or more types of mold release agents may be used. The amount of the release agent added is preferably 1 to 20 parts by weight per 100 parts by weight of the binder 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.

Such a release agent may be used in an amount of about 0.5 to 3 of the weight of the two dye-receiving layers.
A ratio of 0% by weight is good.

When forming the dye-receiving layer, if a reflective image is required, titanium oxide, zinc oxide,
Pigments and fillers such as kaolin clay, calcium carbonate, and finely powdered silica can be added. Further, in the case of OHP or the like, the dye-receiving layer is made substantially transparent.

The dye-receiving layer formed as described above may have any thickness, but for boat fishing, it has a thickness of 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.

The anti-slip/curl layer, which mainly characterizes the present invention, prevents the thermal transfer image-receiving sheet from curling due to the heat of the thermal head during thermal transfer, and also reduces the coefficient of friction with the dye-receiving layer when overlapped, thereby improving the slip property. It is made from a resin with low heat-stretchability and a filler.

Preferred examples of resins with low thermal elasticity include acrylic resins, polyurethane resins, polycarbonate resins, vinylidene chloride resins, epoxy resins, polyamide resins, polyester resins, etc. Among these, resins with various thermal properties Particularly preferred resins are JIS-6734 (100°C, 10ml heat shrinkage rate in the range of -1.0 to 1.5%, 90%
It has a softening temperature of ℃ or higher.

In addition, the fillers used include fluororesin, polyamide resin, styrene resin, styrene/acrylic crosslinked resin,
Examples include plastic pigments such as phenol resin, urea resin, melamine resin, aryl resin, polyimide resin, and benzoguanamine resin, and inorganic fillers such as calcium carbonate, silica, clay, talc, titanium oxide, magnesium hydroxide, and zinc oxide. Among these, particles with particularly high heat resistance are preferred, and the particle size is preferably about 0.5 to 30 um.

These fillers can be used alone or as a mixture, and the type of filler is selected depending on the intended use of the resulting thermal transfer image-receiving sheet. For example, in the case of a thermal transfer image-receiving sheet for reflective images, it does not matter if the anti-curl layer is opaque, so inorganic fillers with low transparency such as titanium oxide or zinc oxide may be used. It is preferable to use a highly transparent plastic pigment or an inorganic filler with a small particle size. The amount used varies depending on the type of filler used, but - For boat fishing, the amount of filler in the anti-slip/curl layer is 0.
．． 02 to 10% by weight, the preferred range is 0.05%
The content ranges from 2% by weight to 2% by weight. If the amount of filler is less than the above range, the slip property improvement effect will be insufficient, while if it exceeds the above range, the transmitted light will be heavily scattered in transparent applications such as OHP, and the light transmittance will also decrease. Therefore, it is not desirable.

The method for forming the anti-slip/curl layer is to add the above-mentioned filler to the above-mentioned resin and further add necessary additives, and then dissolve it in a suitable organic solvent, or to form a dispersion in which it is dispersed in an organic solvent or water. For example, it is a method of coating and drying by a forming method such as a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate, etc., and the thickness of the formed anti-curling layer is 1 to 10.
It is generally around LLm. In addition, when forming the anti-curl layer, if the adhesion between the anti-curl layer and the base sheet is not good, a brimer layer may be formed on the base sheet in advance from polyurethane resin, polyester resin, acrylic resin, epoxy resin, etc. It is preferable.

Furthermore, the image-receiving sheet of the present invention can have a cushion layer between the base sheet and the dye-receiving layer, if necessary.
By providing such a cushioning layer, an image corresponding to the image information can be transferred and recorded with good reproducibility with less noise during printing.

Furthermore, it is also possible to provide a detection mark. The detection mark is extremely convenient when positioning the thermal transfer sheet and the image receiving sheet, and for example, a detection mark that can be detected by a phototube detection device can be provided by printing on the back surface of the base sheet. Of course, these detection marks may be removable.

The thermal transfer sheet used when carrying out thermal transfer using the thermal transfer image-receiving sheet of the present invention as described above is one in which a dye layer containing a sublimable dye is provided on a sheet of paper or a polyester film, and conventionally known thermal transfer sheets are All can be used as they are in the present invention.

In addition, any conventionally known means for applying thermal energy during thermal transfer can be used, such as thermal printers (for example,
By controlling the recording time using a recording apparatus such as 100-100), the intended purpose can be fully achieved by applying thermal energy of about 5 to 100 mJ/mrn''.

(Effects) According to the present invention as described above, by forming the anti-curl layer of the thermal transfer image-receiving sheet from a resin containing a filler and having a low thermal expansion/contraction rate, it has excellent anti-curl properties and slip properties in a printer. A thermal transfer image-receiving sheet capable of forming high-quality images without printing trouble is provided.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. It should be noted that 5 parts or % in the text is based on weight unless otherwise specified.

Example 1 A transparent polyethylene terephthalate film (T-75, thickness 75 um, manufactured by Toshi ■) was used as a base sheet, and a coating liquid having the following composition was applied to one side of the film using a bar coater at a rate of 5.0 g/dry when dried. After drying with a dryer, the dye was dried in an oven at 80° C. for 10 minutes to form a dye-receiving layer.

East Gonu J ■ Shihiki 1 Boso: Polyester (Byron 600. Manufactured by Toyobo ■) 4,0
Part vinyl chloride/vinyl acetate copolymer f#1000A, manufactured by Denki Kagaku Kogyo ■) 6.0 parts Amino-modified silicone (X-22-3050C1 manufactured by Shin-Etsu Chemical Company ■) 0.2 part Epoxy-modified silicone [X-22- 300QE, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 parts Methyl ethyl ketone/toluene (weight ratio 1/1) 89.6 parts A primer layer coating solution having the following composition was applied to the back side of the above film using a bar coater when dry. 0g/rr? The coating liquid for the anti-curl layer with the following composition is applied to the surface using a bar coater at a drying rate of 3.0 g/m'', and dried using a hair dryer. After drying, place in an oven at 80"C for 1 hour.
An anti-curl layer was formed by partially drying, and a thermal transfer image-receiving sheet of the present invention was prepared.

Brimer voice group: Polyester polyol (Atocoat, Toyo Morton)
15.0 parts methyl ethyl ketone/dioxane (weight ratio 2/1) 85.0 parts Curl acrylic resin (BR-85, manufactured by Mitsubishi Rayon ■) 10.
0 part filler (Orgasol 2002D, manufactured by Nippon Rilsan ■) 0.1 part methyl ethyl ketone/toluene (weight ratio 1/1) 89.
9 parts Example 2 Instead of the base sheet in Example 1, a transparent polyethylene terephthalate film (T-100, thickness 100μ
A thermal transfer image-receiving sheet of the present invention was obtained in the same manner as in Example 1, except that the heat transfer image-receiving sheet of the present invention was used in the same manner as in Example 1.

Example 3 In place of the base sheet in Example 1, a transparent polyethylene terephthalate film (T-125, thickness 125 μm) was used.
A thermal transfer image-receiving sheet of the present invention was obtained in the same manner as in Example 1, except that the heat transfer image-receiving sheet of the present invention was used in the same manner as in Example 1.

Examples 4 to 9 In place of the base sheet in Example 1, a transparent polyethylene terephthalate film (T-100, thickness 1004
A thermal transfer image-receiving sheet of the present invention was obtained in the same manner as in Example 1 except that the following fillers were used.

A: Orgasol 20020 = 0. 1st Part Blood 22 Orgasol 2002UL-D=0. Part 1! n
Sodan: Thyroid 244 (manufactured by Fuji Davison ■) = 0.
1 part bundle standing plate unilburonshi-5 (manufactured by Daikin Industries ■) = 0.
Part 1! Practice Godan: Magster #5 (manufactured by Tateho Chemical) = 0,1
Part X seed plate; Orgasol 2002D = 0. 1 part 10 Rubron L-5 = 0.02 parts Comparative Examples 1 to 3 Examples 1 to 3, except that no filler was used and the solvent was 90.0 parts in the anti-curl layer coating solution. Thermal transfer image-receiving sheets of Comparative Examples 1 to 3 were obtained in the same manner as in Examples 1 to 3.

Usage Example A yellow sublimation thermal transfer sheet (manufactured by Dainippon Printing Co., Ltd.) and the thermal transfer image-receiving sheets of the present invention and comparative examples described above were stacked with their respective dye layers and dye-receiving surfaces facing each other, and a thermal sublimation transfer printer was prepared. (vy-50, ■Rear made by Hitachi) was used to print from the back side of the thermal transfer sheet with a thermal head at a printing energy of 90 mJ/mrn' to obtain a printed matter.

1 Plate Direction (1) Printed Curl Degree The obtained printed matter was cut into A4 size, placed on a flat surface, and the curl of the printed matter was evaluated by measuring the distance from the flat surface. The measurement locations were the four corners of the printed matter, and the values are shown as average values.

(2) Paper feeding and discharging properties When printing in the above usage example, 50 thermal transfer image-receiving sheets were stacked and set in the printer paper feeding unit to perform continuous printing. However, in order to make it suitable for sensors, the leading edge and both sides of the thermal transfer image-receiving sheet were coated with white ink, and marks were further added with black ink. The above evaluation was repeated five times, and if two or more thermal transfer image-receiving sheets were fed in duplicate during paper feeding or a paper jam occurred in the thermal transfer image-receiving sheet printed on during paper ejection, it was evaluated as N or G, and there was no problem. If the case is 0,
Closed.

The results shown in Table 1 below were obtained.

As is clear from Table 1 below, by adding a filler to the anti-curl layer, it not only has an anti-curl effect but also has excellent slip properties, which solves the problem of paper conveyance during paper feeding and paper ejection. Ta.

Claims (4)

[Claims] (1) Consists of a base sheet, a dye-receiving layer formed on the surface of the base sheet, and an anti-curl layer formed on the back side of the base sheet, and the anti-curl layer is made of a filler-containing resin with a low thermal expansion/contraction rate. A thermal transfer image-receiving sheet characterized by being formed from. (2) The thermal transfer image-receiving sheet according to claim 1, wherein the amount of the filler added is in a range of 0.02 to 10.0% by weight of the anti-curling layer. (3) Resin JIS-K-6734 (100℃, 10m
in. ) has a heat shrinkage rate of -1.0 to 1.5%
The thermal transfer image-receiving sheet according to claim 1, wherein the thermal transfer image-receiving sheet is in the range of . (4) The thermal transfer image-receiving sheet according to claim 1, wherein all of the dye-receiving layer, the base sheet, and the anti-curl layer are substantially transparent.