JP3345669B2 - Thermal transfer image receiving sheet for OHP - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Thermal transfer recording, in which information is recorded by transferring a coloring material such as a dye on a thermal transfer sheet onto an image receiving sheet by heating a thermal head or the like, is well known. The present invention relates to an improvement in an image receiving sheet used for the thermal transfer recording.

[0002]

2. Description of the Related Art There are various thermal transfer recording systems in which a thermal transfer sheet is heated by a heating device such as a thermal head and a laser, and a color material such as a dye on the thermal transfer sheet is transferred onto an image receiving sheet to record information. It is used as an information recording means in the field, and has been actively used in recent years for producing a transmission type original used for a projection apparatus such as an overhead projector (hereinafter abbreviated as OHP). Conventionally, OHP image-receiving sheets used for such purposes have been
Polyethylene terephthalate (P
For example, a structure in which a receiving layer for receiving a coloring material such as a dye, a back surface layer, and the like are formed on the surface of a transparent sheet-like base material such as ET) depending on the application.

[0003]

In the conventional OHP image-receiving sheet, the surface of the image-receiving layer to which a particularly high energy is given becomes rough due to heat from a heating device such as a thermal head. When the image is projected by the OHP, there is a problem that the information of the portion looks dark.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is intended to prevent the surface of an image receiving layer from being roughened by heat from a heating device such as a thermal head and to provide a high-density, high-sensitivity OHP capable of heat transfer. It is intended to provide a thermal transfer image receiving sheet for use .

[0005]

In order to achieve the above object, in the thermal transfer image-receiving sheet for OHP of the present invention, at least two of an innermost layer for image reception and an outermost layer for image reception are provided on one side of a transparent substrate sheet. An image receiving layer comprising at least two layers is provided, and the innermost image receiving layer is crosslinked with a curing agent.

Further, in order to achieve the above object, in the thermal transfer image receiving sheet for OHP of the present invention, the coating amount of the outermost layer for image receiving is set to 1.5 g / m ² or less,
The curing agent to be added to the innermost layer for image reception is represented by the following general formula (1).

Embedded image It is characterized by containing at least one kind of chelate curing agent or alcoholate as shown below. As described above, since the innermost image receiving layer on the base material is cross-linked by the curing agent, it is possible to prevent the surface of the image receiving layer from being roughened due to heat from the heating device, and furthermore, it is possible to prevent the innermost layer for image receiving from being overlaid. The coating amount of the outermost image receiving layer containing no curing agent is 1.5 g / m
^By providing it at ² or less, particularly preferably at 1.0 g / m ² or less, high sensitivity and high density can be achieved without impairing the effect of preventing the surface of the image receiving layer from being roughened.

Next, the present invention will be further described with reference to preferred embodiments. The material of the base sheet used in the present invention is transparent.
It is not particularly limited as long as it is clear , for example, polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, ethylene
Vinyl alcohol copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyetheretherketone, polysulfone, polyethersulfone, tetrafluoroethylene / perfluoroalkylvinylether, polyvinyl Fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride and the like can be mentioned.

The image receiving layer formed on the surface of the base sheet receives the sublimable dye migrating from the thermal transfer sheet and maintains the formed image. As a thermoplastic synthetic resin for forming the innermost layer for image reception,
For example, polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, polyvinyl acetate, ethylene / vinyl acetate copolymer, vinyl chloride / vinyl acetate copolymer, and vinyl such as polyacrylester Resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers, and cellulose resins such as cellulose diacetate Resins, polycarbonate-based resins, polyvinyl acetal-based resins, polyvinyl alcohol-based resins, and the like can be given. The resin used as the innermost layer for image reception is composed of at least one of the above materials, and at least one resin having a reactive group capable of reacting with a curing agent, for example, a hydroxyl group, a carboxy group, an amino group and the like. Must be included.

The resin constituting the outermost layer for receiving an image does not necessarily need to include a reactive group capable of reacting with a curing agent, and any combination of resins for an image receiving layer is possible. Needs to be 1.5 g / m ² or less, particularly preferably 1.0 g / m ² or less. 1.5g / m
^If the coating amount is more than ^2, roughening of the image receiving layer surface in the high-density printing portion cannot be prevented. Further, in the configuration having no surface layer and only the image-receiving layer on the substrate side, it is possible to prevent the surface of the image-receiving layer from being roughened, but the dye-dyeing property of the image-receiving layer cured by the curing agent is deteriorated. Therefore, there arises a problem that the dyeing sensitivity and the density are reduced.

A back layer may be provided on the back side of the thermal transfer sheet in order to prevent the sheet from being transported mechanically and to prevent curling. Furthermore, in order to prevent troubles such as transport failure of the thermal transfer sheet due to static electricity, the base film, the release layer, the mat layer, the innermost layer for image reception, the outermost layer for image reception, the adhesive layer, the base material of the image receiving sheet, It is preferable to include an antistatic agent in at least one layer. As such an antistatic agent, fatty acid esters, sulfates, phosphates, amides, quaternary ammonium salts, betaines, amino acids, ethylene oxide adducts and the like are effectively used. The amount of the antistatic agent used varies depending on the layer to which the antistatic agent is added and the type of the antistatic agent. In any case, the surface resistance of the transfer layer of the receiving layer or the base material of the image receiving sheet is 10 ⁸ to 10. ^It is in a range of ¹² Ω · cm ² , and quantitatively 0.01 to 0.5 g / m ²
Is preferably used. When the amount of the antistatic agent used is 0.01
When it is less than g / m ² , the antistatic effect is insufficient. On the other hand, when it is more than 0.5 g / m ^2, it is too much and is uneconomical.
In addition, problems such as stickiness occur.

[0011]

【Example】

(Example 1) An innermost layer for image reception composed of the following composition was formed on a transparent substrate sheet of a 100 µm-thick polyester film (manufactured by Toray Industries, Inc.) by a roll coating method.
The coating amount is 3.5 g / m ² (when dried). Composition of innermost layer for image reception Vinyl chloride-vinyl acetate copolymer 100 parts (weight ratio) (VAGH, manufactured by Union Carbide) Amino-modified silicone 3 parts (weight ratio) (KF-393, Shin-Etsu Chemical Co., Ltd.) Epoxy-modified Silicon 3 parts (weight ratio) (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) Chelate hardener 8 parts (weight ratio) (Orgatics TC-100, manufactured by Matsumoto Trading Co., Ltd.) Toluene 200 parts (weight ratio) Methyl ethyl ketone 200 Parts (weight ratio) Isopropanol 50 parts (weight ratio)

Further, an outermost image receiving layer having the following composition was formed on the innermost image receiving layer by a roll coating method to obtain a thermal transfer image receiving sheet for OHP of the present invention. The coating amount of the outermost layer for image reception is 0.8 g / m ² (at the time of drying). Composition of outermost layer for image reception 100 parts polyester resin (weight ratio) (Byron 200, manufactured by Toyobo Co., Ltd.) 3 parts amino modified silicone (weight ratio) (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts epoxy modified silicon (weight) (Ratio) (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) Toluene 300 parts (weight ratio) Methyl ethyl ketone 300 parts (weight ratio)

Example 2 100 μm thick polyester film (Toray Industries, Inc.)
The innermost layer for image reception composed of the following composition was formed on the transparent base material sheet of the present invention by a roll coating method. The coat amount is
3.5 g / m ² (when dry). Composition of innermost layer for image reception Polyester resin 100 parts (weight ratio) (Byron 200, manufactured by Toyobo Co., Ltd.) Polyvinyl alcohol 10 parts (weight ratio) (Denkapovar, manufactured by Denki Kagaku Kogyo Co., Ltd.) Amino-modified silicone 3 parts (weight ratio) (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) Epoxy modified silicon 3 parts (weight ratio) (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) Chelate hardener 8 parts (weight ratio) (Orgatics TC-100, Matsumoto (Manufactured by Koshosha) Toluene 200 parts (weight ratio) Methyl ethyl ketone 200 parts (weight ratio) Isopropanol 50 parts (weight ratio) Further, the outermost image receiving layer having the same composition as in Example 1 was roll-coated on the innermost image receiving layer. And O 2 of the present invention
A thermal transfer image-receiving sheet for HP was obtained. The coating amount of the outermost image receiving layer is 1.0 g / m ² .

(Example 3) The thermal transfer for OHP of the present invention was carried out in the same manner as in Example 1 except that aluminum chelate D (manufactured by Kawaken Fine Chemicals Co., Ltd.) was used as the chelate curing agent for the innermost layer for image reception. An image receiving sheet was obtained. (Example 4) The same procedure as in Example 1 was carried out except that Olgatics ZC-150 (manufactured by Matsumoto Trading Co., Ltd.) was used as the chelate curing agent for the innermost layer for image receiving, and the thermal transfer image receiving apparatus for OHP of the present invention was used. I got a sheet. Example 5 A thermal transfer image-receiving sheet for OHP of the present invention was obtained in the same manner as in Example 1 except that the following coating solution was used as the outermost layer composition for image receiving. Composition of outermost layer for image reception Vinyl chloride / vinyl acetate copolymer (VAGH, manufactured by Union Carbide Co., Ltd.) 100 parts Amino-modified silicon (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts Epoxy-modified silicon (X- 22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts Toluene 300 parts Methyl ethyl ketone 300 parts

[0015]

Comparative Example 1 A thermal transfer image-receiving sheet for OHP was prepared in the same manner as in Example 1 except that the coating amount of the innermost layer for image reception in Example 1 was 4.3 g / m ² and the outermost layer for image reception was removed. I got (Comparative Example 2) A thermal transfer image-receiving sheet for OHP was obtained in the same manner as in Example 1, except that the coating amount of the outermost image receiving layer in Example 1 was 4.3 g / m ² and the innermost layer for image receiving was removed. . (Comparative Example 3) A thermal transfer image-receiving sheet for OHP was obtained in the same manner as in Example 1 except that the coat amount of the outermost layer for image reception in Example 1 was changed to 2.0 g / m ² .

The thermal transfer image-receiving sheet for OHP of the present invention and the comparative example described above and a commercially available thermal transfer sheet are overlapped with their respective dye surfaces and dyeing surfaces facing each other. Recording was performed from the back side with the thermal head under the conditions of a thermal head applied voltage of 12.0 V and a pulse width of 16 tones of 1 to 16 msec, and the results in Table 1 below were obtained. In addition, the evaluation method of each performance shown in Table 1 was performed as follows.

[Table 1] (1) Printing Sensitivity (OD) The transmission density and reflection density at the 12th gradation of each image were measured with a Macbeth densitometer, and the relative values were set to 1.00 in Example 1 and indicated as relative values. (2) Roughening of the surface of the image receiving sheet Each sheet is projected on an overhead projector (OHP), and a yellow, magenta, and cyan high-density portion is formed.
It was visually evaluated whether darkening of the color due to the surface roughening occurred. Marks in the table are not considered black, and x marks indicate presence. (3) Print Density (OD) The transmission density of the highest applied energy portion of each image was measured with a Macbeth densitometer.

As shown in Table 1, Comparative Examples 1, 2, and 3 produced darkening or had a low print density, whereas Examples of the present invention did not have any darkening.
The print density was also high.

[0019]

As described above, the present invention provides an image receiving innermost layer and an image receiving outermost layer on a transparent substrate sheet.
Since at least two image-receiving layers are provided and the innermost image-receiving layer is cross-linked with a curing agent, the surface of the OHP image-receiving layer is not roughened by heat from a heating device such as a thermal head. There is no blackening of the print due to surface flattening, high density of print that could not be obtained by the conventional method,
And the effect of high sensitivity was obtained.

Continuation of the front page (56) References JP-A-4-229293 (JP, A) JP-A-5-85066 (JP, A) JP-A-3-99887 (JP, A) JP-A-4-99697 (JP) JP-A-4-103395 (JP, A) JP-A-4-187494 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (3)

(57) [Claims] 1. An OHP having an image receiving layer (4) comprising at least two layers of an innermost image receiving layer (2) and an outermost image receiving layer (3) on one side of a transparent substrate sheet (1) . A thermal transfer image receiving sheet for OHP, wherein the image receiving innermost layer (2) is crosslinked with a curing agent in the thermal transfer image receiving sheet (5). 2. The coating amount of the outermost image receiving layer is 1.5 g / m.
^2. The OHP thermal transfer image-receiving sheet according to claim 1, wherein the number is ² or less. 3. The OH according to claim 1, wherein the curing agent added to the innermost image receiving layer contains at least one of a chelating agent represented by the following general formula (1) or an alcoholate.
Thermal transfer image receiving sheet for P. Embedded image