JPS6287398A - Writing sheet and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a writing sheet used for electronic blackboards, whiteboards, etc., which has a surface that allows repeated writing and erasing with a predetermined marker.

<Conventional technology> In recent years, white boards or sheets have become rapidly popular in the field of teaching materials and stationery, as they do not use chalk, do not stain hands with powder, and can be written on and erased repeatedly. With electronic blackboards, information written on a white writing sheet can be reduced and copied on the spot to an easy-to-handle A4 size, etc., so there is no need to take notes at each meeting or seminar. It is attracting attention in various fields because it can dramatically improve the efficiency of

The information written on the writing sheets used as surface materials for electronic blackboards, whiteboards, etc. is not just text, but also includes many figures such as tables, graphs, illustrations, etc. It would be convenient to have formats such as monthly schedules, work instructions, Japanese blank maps, golf score sheets, staff notations, grids, or any other formats printed on the surface of the machine, and there is a strong demand from customers.

However, the surface of the writing sheet has physical properties that allow it to be repeatedly written with a designated marker and erased with an eraser. , format] itself is also erased. Further, in the case of an electronic blackboard, a writing sheet for about five screens is usually wound up and rewinded to be electrically driven. Therefore, it is necessary to print a different format for each screen of a long writing sheet for five screens in accordance with the customer's requirements, making it difficult to select an appropriate printing method and being quite limited.

For example, when printing on the surface of a writable and erasable resin layer constituting a writing sheet using a screen printing method, which is considered to be relatively suitable for such printing, the adhesion of the screen printing ink is reduced due to the releasability of the resin surface. Worse, in addition to the problem of formatting being erased when trying to erase normal written information many times with an eraser, or during the process of winding up a long writing sheet many times,
1) Cracks occur in the printing ink layer during the rolling operation of a long writing sheet; 2) Information recorded with a marker that is difficult to erase with an eraser because it is mistaken for a special marker during normal writing operations. When erasing images with organic solvents, there were problems such as erasing the format itself or causing smearing on the lines.

As a countermeasure to this problem, it may be possible to apply arbitrary printing such as a format on the surface of a support such as a milky white polyester film, but in this case, It is extremely difficult to continuously print FORMATS I for each screen, 2) Dust easily adheres during the printing process, reducing the commercial value of the product, 3) Adhesion due to the thickness of the printing ink layer consisting of the number 1.01411+ The layers cannot be applied properly.

Due to these problems, it is difficult to find a means for printing a suitable format for practical use.

<Problems to be solved by the invention> ゛ The present invention has been made in view of the above circumstances,
To perform arbitrary printing, such as format printing, which enables high-mix, low-volume printing with a relatively simple operation process and has excellent practicality such as erasure resistance, on a writing sheet used as a surface material for electronic blackboards, whiteboards, etc. This is what makes it possible.

Note that arbitrary printing as used in the present invention refers to figures, tables,
It refers to all printed images such as line drawings in the form of numbers, etc., solid printing, halftone dot printing, etc. having arbitrary areas and shapes. In addition, in this case, solid printing and halftone dot printing of any area and shape include a wide range of printed images, including, for example, full-screen printing of one screen of a writing sheet.

<Means for Solving the Problems> The support constituting the writing sheet in the present invention is usually a sheet-shaped sheet colored in white so that it can be clearly read when written on the surface of the writing sheet with a colored marker. For example, 50 to 250 pm milky white polyester film, transparent polyester film with a white pigment layer, white coated paper, synthetic paper, etc. are used, but from the viewpoint of hardness and handling, 100 to 150 um A milky white polyester film is relatively preferably used.

The writable and erasable resin may be any material that can easily erase information written with a marker on the surface of the coating layer of the resin with an eraser, such as ultraviolet curable unsaturated polyester resin, silane resin, Acrylic resins and the like are applicable to the writable and erasable resin of the present invention.

Further, the sublimable dye ink used in any printing of the present invention is composed of the following sublimable dye and vehicle components. That is, disperse dyes are mainly applied as sublimable dyes. For example, C,1,Disperse dyes are used as blue dyes.
Anthraquinone dyes such as Blue 3, azo dyes such as C,1, Disperse Violet 12, and C,1, Disperse Violet 4 as purple dyes.
Anthraginone dyes such as C, I as red dyes.

Disperse Red] Azo dye such as 7, C
, I, DisperseRed 4, and other anthraginone dyes; C,1, Disperse as an orange dye;
Azo dyes such as Orange 3 are applicable.

Further, resins constituting the vehicle component include ethyl cellulose, hydroxyethyl cellulose, cellulose acetate propionate, alkyd resins, polyvinyl alcohol, etc., while solvents constituting the vehicle component include ethyl alcohol, isopropyl alcohol, toluene, and acetic acid. Ethyl, ethylene glycol monoethyl ether, etc. are applicable. The writing sheet of the present invention can be produced using these materials by the following method.

First, a sheet is prepared by coating a writable and erasable resin on a support made of a milky white polyester film or the like.

In this case, the coating method is a commonly used reverse roll coater or wire doctor one-way method, and the resin solution as described above is coated and dried to a coating thickness of 1 to 11,000 μm after drying, and further as necessary. It is preferable to cure the coating film by irradiating it with ultraviolet rays or by heat treatment.

On the other hand, an original sheet is produced by printing a predetermined format with sublimation dye ink on a base material such as paper using ordinary printing means such as lithographic printing and gravure. In this case, the format is a reverse image printed on the original sheet so that it becomes a fixed image after thermal transfer. Furthermore, at this time, by selecting an arbitrary color for the sublimable dye, it is possible to print in various single colors, or it is also possible to perform full-color printing by applying ordinary photolithography.

Next, the printed surface of the original sheet is superimposed on the resin surface of a sheet made by coating a write-erasable resin on a support, and the sublimable dye in the sublimable dye ink is sublimated onto the resin layer by heat-pressing. After the transfer, the original sheet may be removed. The conditions for heat-press transfer in this case vary depending on the composition of the sublimable dye and the resin material, but are generally 180°C to 20°C.
The writing sheet of the present invention can be obtained by pressing each screen at a temperature of 0° C. with a hot plate or by continuously heating and pressing with a hot roll.

In this way, the format image made of the sublimable dye printed on the coated surface of the writable and erasable resin of the writing sheet is not only simply colored on the surface of the resin due to the strong penetrating power of the dye molecules. It permeates through the resin layer and reaches the surface and interior of the support. This enables stable format printing with excellent abrasion resistance on the surface of the writable and erasable resin layer.

The writing sheet of the present invention obtained as described above can be applied to an electronic blackboard by processing it into a long sheet for several screens or an endless sheet, or can be applied to a white board (white board) by pasting it on a board surface such as plywood or metal plate. Alternatively, it can be used as a simple writing sheet by cutting it into an appropriate size without any processing and pasting it on a bulletin board or wall.

<Example> The present invention will be explained in detail with reference to Examples below.

Example 1 A coating solution consisting of the following was applied to one side of a 125-thick opalescent polyester caranal support so that the coating thickness after drying was 3 pm. After drying, the coating was cured by irradiation with a mercury lamp to form a sheet. was created.

On the other hand, an offset printing machine using a sublimable dye ink consisting of 6 parts by weight of an anthraquinone disperse dye and 94 parts by weight of a vehicle component consisting of ethyl cellulose, ethyl alcohol, and ethyl acetate was used to print a blue square format on high-quality paper. A sheet was produced.

The format printed side of the obtained original sheet and the writable and erasable resin coated side of the sheet are overlapped 20
A format image of the sublimable dye was transferred onto the coated surface using a heating transfer device at 0° C. to produce a writing sheet of the present invention.

When this writing sheet was applied to an electronic blackboard and a special marker was used to write information such as various letters and numbers using normal operations and a reduced copy was made, a clear copy including the format was obtained. The effectiveness of format printing was confirmed. Furthermore, even if the written information such as letters and numbers was erased many times with an eraser, the format was not erased at all and was extremely stable.

Example 2 A sheet was prepared by applying the resin coating liquid used in Example 1 to a support made of white art paper having a thickness of 140 μm, drying, and curing with ultraviolet light.

On the other hand, sublimable dye 15 consisting of a combination composition of the following four colors
Using a sublimable dye ink consisting of 85 parts by weight and a vehicle component of ethyl cellulose and ethyl alcohol, an original sheet was produced by printing a black map of Japan in a format on high-quality paper using an offset printing machine.

The format printed surface of the obtained original sheet and the writable and erasable coated surface of the sheet are superimposed, and the format image of the sublimable dye is transferred to the coated surface using a heating transfer device at 200° C. to obtain the writing sheet of the present invention. was created.

When the practical characteristics of this writing sheet were evaluated in the same manner as in Example 1, it was confirmed that the writing sheet had excellent characteristics in format printing using sublimable dyes.

Example 3 A silane hard coating agent (Si Coat 727, manufactured by Daihe Kagaku Kogyo Co., Ltd.) was coated on a support made of a 125 um thick opalescent polyester film so that the coating thickness after drying was 3 coats, and then dried. The coating film was cured by heat treatment for 2 minutes at °C to produce a sheet.

On the other hand, azo-based red sublimable dye and Example 2-11
= 15 parts by weight of each of the black sublimable dyes used in Example 2 and 85 parts by weight of the vehicle component used in Example 2 were kneaded to prepare two types of sublimable inks, red and black.

Using these two types of sublimation dye inks, an original sheet was produced by performing two-color format printing (red and black) on high-quality paper using an offset printing machine.

The format printed side of the obtained original sheet and the writable and erasable resin coated side of the sheet are overlapped 20
A two-color format image was transferred onto the film surface using a heating transfer device at 0° C. to produce a writing sheet of the present invention.

This writing sheet was applied to a thermosensitive electronic blackboard with a color separation mechanism and two-color recording capability, and when predetermined written information was recorded with a marker and a reduced copy was made, the two-color format image on the original sheet was reproduced. A clear copy was obtained. Furthermore, even with repeated erasing operations using an eraser, the two-color format was completely stable and was not erased at all.

<Effects of the Invention> Since the present invention has the above-mentioned configuration, it is possible to print in any format at low cost with simple operations on the write-erasable resin coated surface of a writing sheet used for electronic blackboards, whiteboards, etc. Moreover, since the sublimable dye image of any printed image penetrates into the inside of the resin layer and the support layer, it will not be erased even if rubbed with an eraser, and any printing processing such as format printing is extremely stable. It has become possible. Especially when applied to electronic blackboards, by separately preparing multiple original sheets with arbitrary printing, it becomes possible to perform so-called high-mix, low-volume printing on each side of a long writing sheet. It has become possible to apply it to a wide range of uses.

In addition, by arbitrarily selecting various types of sublimation dye inks for the original image on the original sheet, multicolor or full-color printing is possible on the writing sheet, and a recording mechanism with color separation function is built into the electronic blackboard. Then, you can instantly reduce the large color image on the writing sheet surface and obtain a color copy.

Claims (1)

[Scope of Claims] 1. A writing sheet comprising a support coated with a writable and erasable resin, the resin surface being optionally printed with a sublimable dye. 2 The printed surface of the original sheet, which has been arbitrarily printed with sublimation dye ink on the base material, is superimposed on the resin surface of the sheet formed by coating a write-erasable resin on the support, and the sheet is heat-pressed. A method for producing a writing sheet, characterized in that after sublimation-transferring a sublimation dye onto the resin side, the original sheet is separated to perform arbitrary printing.