JP2930958B2 - Heat transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet to be thermally transferred.

[Conventional technology]

The heat transfer sheet is superposed with the image receiving layer surface facing the color material layer of the transfer sheet having the color material layer containing the heat transferable dye, and is controlled by an electric signal according to image information from the back of the heat transfer sheet. By heating the thermal transfer sheet with a heating means such as a thermal head, the dye in the color material layer can be transferred to the image receiving layer to form a transferred image.

[Problems to be solved by the invention]

However, the conventional heat transfer sheet cannot record and form a transfer image with good reproducibility as desired because the sensitivity at the time of image recording is still insufficient.

The present invention has been made in view of the above problems, and has as its object to provide a heat transfer sheet excellent in sensitivity at the time of image recording.

[Means for solving the problem]

The present invention provides: (1) a heat transfer sheet comprising a sheet base material and an image receiving layer formed on the base material and receiving a dye transferred from the heat transfer sheet by heating, wherein the image receiving layer comprises at least vinyl chloride and ether. A heat transfer sheet formed of a resin for forming an image receiving layer comprising a copolymer with an acrylic acid-based monomer having a bond.

(2) The heat transfer sheet according to claim 1, wherein the resin for forming an image receiving layer is a mixed resin of a copolymer of vinyl chloride and an acrylic acid monomer having an ether bond, and another resin.

(3) The heat transfer sheet according to claim 1 or 2, wherein an intermediate layer is provided between the sheet substrate and the image receiving layer.

(4) The heat-transferable sheet according to claim 1, wherein a release agent layer is provided on the surface of the image receiving layer. "

Examples of the sheet substrate used in the present invention include a plastic film, synthetic paper, cellulose fiber paper and the like. As the plastic film, a film made of a resin such as polyester, polyvinyl chloride, polypropylene, polyethylene, polycarbonate, or polyamide can be used, and a white film or fine foam formed by adding a filler to these films is used. Foamed films can also be used. As synthetic paper, a polyolefin resin or other synthetic resin as a resin component, an inorganic charging agent and the like are added thereto, mixed, and extruded,
Alternatively, a film produced by applying an extender to the surface of a film of a polystyrene resin, a polyester resin, a polyolefin resin, or the like is used. As cellulose fiber paper,
Fine paper, coated paper, cast coated paper, synthetic rubber latex or synthetic resin emulsion impregnated paper can be used.

For applications requiring transparency as a sheet base material (such as for overhead projectors) or applications where heat is transferred to an article such as a card or cloth, an adhesive or the like may be applied to the side opposite to the image receiving layer of a transparent plastic film. A white film, a foamed film, a synthetic or cellulose fiber paper may be attached as the applied support or the material for imparting shielding properties. Further, a sheet substrate in which plastic films, synthetic papers, or cellulose fiber papers are bonded together with an adhesive can be used.

The image receiving layer is formed of an image receiving layer forming resin capable of receiving a dye transferred from a thermal transfer sheet during thermal transfer recording, and the dye is dyed to form a transferred image. The image receiving layer forming resin in the present invention,
It is composed of a copolymer of at least vinyl chloride and an acrylic acid monomer having an ether bond.

The usual vinyl chloride represented by the following formula is used.

As the acrylic acid-based monomer having an ether bond, for example, the following can be used.

... However, R, R '= - C n H 2n + 1, or -H l = 1 to 50 (preferably _{3~20) ··· B'OC V H 2V S} B v = 1-10, s = 1-20 The copolymerization ratio of vinyl chloride and the acrylic acid monomer having an ether bond is as follows: vinyl chloride / acrylic acid monomer = 99-50 / 1 / 1-50, preferably 95 ~ 80/5 ~ 20.

Other acrylic acid-based monomers can be contained in the copolymer composed of the above two components. Other acrylic acid-based monomers include acrylic acid; acrylates such as calcium acrylate, zinc acrylate, magnesium acrylate, and aluminum acrylate; methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and 2-ethoxyl. Acrylates such as acrylate, 2-hydroxyethyl acrylate, n-stearyl acrylate, tetrahydroxyfurfuryl acrylate, and trimethylolpropane triacrylate; methacrylic acid; methyl methacrylate, ethyl methacrylate, t-butyl methacrylate, tridecyl methacrylate , Cyclohexyl methacrylate,
And methacrylic acid esters such as triethylene glycol dimethacrylate, 1,3-butylene dimethacrylate, and trimethylolpropane trimethacrylate.

In the present invention, as the resin for forming the image receiving layer, a resin composed of a mixed resin of the above-mentioned copolymer and another resin can be used. The mixing ratio in this case is preferably the above-mentioned copolymer / other resin = 50 to 95/50 to 100. The other resin means a resin other than at least vinyl chloride, and specific examples thereof include polyester resin, polystyrene resin, vinyl acetate resin, AS resin, polyamide resin, epoxy resin, phenol resin, AAS resin, polyacetal resin, Examples include an amino resin, an ethylene-vinyl acetate copolymer resin, and a polybutadiene resin. These may be used in combination of two or more. Among these resins, styrene resins, vinyl acetate resins, and ethylene vinyl acetate copolymer resins include copolymer resins of respective monomers and acrylic acid monomers.

By forming the image receiving layer with the above resin for forming an image receiving layer, it is possible to remarkably improve dyeability of the image receiving layer. This improvement in dye-dyeability is caused by a copolymer resin of vinyl chloride and an acrylic acid monomer having an ether bond.

In forming the image-receiving layer, the image-receiving layer-forming ink composition prepared by adjusting the image-receiving layer-forming resin with a solvent or the like is applied onto a sheet substrate by a conventionally well-known coating means, and is formed by drying. In addition, in the invention, the resin for forming the image receiving layer in an emulsion state can be applied as it is to a sheet substrate. The thickness of the image receiving layer is 1 to 50 μm
It is.

The heat transfer sheet of the present invention is provided with an intermediate layer comprising a cushion layer, a porous layer, and the like between the sheet substrate and the image receiving layer,
By providing this intermediate layer, an image corresponding to image information with little noise can be transferred and recorded with good reproducibility. Examples of the material constituting the intermediate layer include urethane resin, acrylic resin, ethylene-based resin, butadiene rubber, and epoxy resin. The thickness of the intermediate layer is preferably about 2 to 20 μm.

Further, the heat transfer sheet of the present invention can contain a release agent in the image receiving layer in order to improve the releasability from the heat transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants; silicone oil; and silicone oil is preferred.

As the silicone oil, an oily oil can be used, but a curable oil is preferable. Examples of the curable silicone oil include a reaction curable type, a photocurable type, and a catalyst curable type, and a reactive curable type silicone oil is particularly preferable. As reaction hardening type silicone oil,
It is preferable that an amino-modified silicone oil and an epoxy-modified silicone oil are reacted and cured. Examples of the amino-modified silicone oil include KF-393 (manufactured by Shin-Etsu Chemical Co., Ltd.). -22-343 (manufactured by Shin-Etsu Chemical Co., Ltd.). KS-705F-PS (catalyst-curable silicone oil, Shin-Etsu Chemical Co., Ltd.) and KS-720 (photo-curable silicone oil, Shin-Etsu Chemical Co., Ltd.) ) And the like. The addition amount of these curable silicone oils is preferably about 0.5 to 30 parts by weight based on 100 parts by weight of the resin constituting the image receiving layer.

Alternatively, the release agent layer may be provided by dissolving or dispersing the above release agent in an appropriate solvent on the surface of the image receiving layer, applying the solution, and then drying. As the release agent constituting the release agent layer, the above-mentioned cured product of the amino-modified silicone oil and the epoxy-modified silicone oil is particularly preferable. The thickness of the release agent layer is 0.01 to 5 μm, particularly 0.05 to 2 μm
Is preferred.

The heat transfer sheet of the present invention may have a slip layer on the back surface of the sheet substrate. In some cases, the heat transfer sheets are stacked and sent out one by one to perform the transfer. In this case, if a slip layer is provided, the slips between the sheets become smoother.
It can be sent out one sheet at a time. Examples of the material of the lubricating layer include a methacrylate resin such as methyl methacrylate or a corresponding acrylate resin, and a vinyl resin such as a vinyl chloride-vinyl acetate copolymer.

Further, an antistatic agent can be added to the heat transfer sheet. The inclusion of an antistatic agent has the effect of preventing dust from adhering to the heat transfer sheet. The antistatic agent may be contained in the sheet substrate or the image receiving layer, or may be provided as an antistatic agent layer on the back surface of the sheet substrate, but is preferably provided as an antistatic layer on the back surface of the sheet substrate. .

Further, it is possible to provide a detection mark on the heat transfer sheet. The detection mark is extremely convenient when positioning the thermal transfer sheet and the heat transfer sheet, and the like. For example, a detection mark that can be detected by the photoelectric tube detection device can be provided on the back surface of the sheet base by printing or the like.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples.
The following "parts" indicate parts by weight.

Examples 1 to 3, Comparative Example After using a synthetic paper (manufactured by Oji Oil Chemical Co., Ltd .: YUPO FPG150) having a thickness of 150 μm as a sheet substrate, the surface thereof was dried by roll coating with an ink composition for forming an image receiving layer having the following composition. Was applied so as to have a thickness of 9.3 μm, and dried at 80 ° C. for 2 hours to prepare respective heat transfer sheets.

Ink Composition for Forming Image Receiving Layer (Example 1) Resin for Forming Image Receiving Layer: Vinyl chloride: 80 parts PPG800 methacrylate: 20 parts Amino-modified silicone oil: 10 parts (Shin-Etsu Chemical: X-22-3050C) Epoxy-modified silicone oil: 10 parts (Shin-Etsu Chemical: X-22-3000E) Toluene: 100 parts Methyl ethyl ketone: 100 parts For image-receiving layer formation Ink composition (Example 2) Resin for forming image receiving layer-Vinyl chloride ... 70 parts-Vinyl acetate ... 10 parts-PPG800 methacrylate ... 20 parts Amino-modified silicone oil: 10 parts (Shin-Etsu Chemical: X-22-3050C) Epoxy-modified paper silicone oil: 10 parts (Shin-Etsu Chemical: X-22-3000E) Toluene: 100 parts Methyl ethyl ketone: 100 parts Image-receiving layer formation Ink composition (Example 3) Resin for forming image receiving layer-Vinyl chloride ... 80 parts-PPG800 methacrylate ... 20 parts ・ As other forming resin, Byron 200 (manufactured by Toyobo Co., Ltd.)… 100 parts Amino-modified silicone oil… 10 parts (Shin-Etsu Chemical: X-22-3050C) Epoxy-modified silicone oil… 10 parts (Shin-Etsu Chemical: X-22-3000E) Image receiving layer forming ink composition (comparative example) Image receiving layer forming resin (copolymer resin)-Vinyl chloride ... 85 parts-Vinyl acetate ... 15 parts Amino-modified silicone oil ... 10 parts (Shin-Etsu Chemical Co., Ltd.) Manufactured by X-22-3050C) Epoxy-modified silicone oil: 10 parts (Shin-Etsu Chemical: X-22-3000E) Toluene: 100 parts Methyl ethyl ketone: 100 parts (Preparation of thermal transfer sheet) Corona treatment was applied to one side as a support. 9 µm thick polyethylene terephthalate film (Toyobo: S-PE
T), a coating composition for forming a colorant layer having the following composition was applied by wire bar coating so that the applied amount at the time of drying was 1 g / m ² , dried, and silicone oil (manufactured by Shin-Etsu Silicone: X-41) was applied to the back surface. After dropping one or two drops of 4003A) with a dropper, it was spread over the entire surface and coated on the back side to form a thermal transfer sheet.

Coloring material layer forming coating composition Disperse dye: 4 parts (Nippon Kayaku: Kayaset Blue 714) Polyvinyl butyral: 4.3 parts (Sekisui Chemical: S-LEC BX-1) Toluene: 40 parts Methyl ethyl ketone: 40 parts Iso Butanol: 10 parts Each of the heat transfer sheet and the heat transfer sheet obtained as described above are overlapped so that the color material layer and the image receiving layer are in contact with each other, and a thermal head is used from the support side of the heat transfer sheet. Head output: 1W / dot, pulse width:
Printing was performed under the conditions of 0.3 to 0.45 msec and a dot density of 3 dots / mm.

The sensitivity of each sheet to be transferred by the above printing was measured with a densitometer (RD-918, manufactured by Macbeth Co., Ltd.), and each sensitivity value was expressed as a relative sensitivity based on the measurement value of the comparative example. It is shown in the table.

[Effect of the Invention] As described above, the heat transfer sheet of the present invention is formed by forming the image receiving layer with an image receiving layer forming resin composed of a copolymer of at least vinyl chloride and an acrylic acid monomer having an ether bond. Therefore, it becomes excellent in the dyeing property to the dye migrating from the thermal transfer sheet, and as a result,
This has the effect of having excellent sensitivity during image formation and being able to form an image with desired reproducibility.

Further, according to the present invention, by providing an intermediate layer between the sheet substrate and the image receiving layer, it is possible to transfer and record an image with little noise with good reproducibility. Further, by providing a release agent layer on the surface of the image receiving layer, it is possible to improve the releasability from the thermal transfer sheet particularly during thermal transfer recording.

Claims (4)

(57) [Claims] 1. A heat transfer sheet comprising a sheet substrate and an image receiving layer formed on the substrate and receiving a dye transferred from the thermal transfer sheet by heating, wherein the image receiving layer has at least vinyl chloride and an ether bond. A heat transfer sheet formed of an image receiving layer forming resin made of a copolymer with an acrylic acid monomer. 2. An image receiving layer forming resin, comprising: a copolymer of vinyl chloride and an acrylic acid monomer having an ether bond;
The heat transfer sheet according to claim 1, wherein the heat transfer sheet is a mixed resin with another resin. 3. The heat transfer sheet according to claim 1, wherein an intermediate layer is provided between the sheet substrate and the image receiving layer. 4. The method according to claim 1, wherein a release agent layer is provided on the surface of the image receiving layer.
4. The heat transfer sheet according to 2 or 3.