JPS63145090A - Thermal recording indicating material - Google Patents

Abstract

PURPOSE:To improve handwriting performance and erasing performance, by providing a thermal layer mainly composed of resin basic material and organic low molecular substance and having transparency variable reversibly with temperature onto one face of a transparent supporting material, and providing a resin layer containing a silane compound onto the other face. CONSTITUTION:A thermal layer 2 mainly composed of resin basic material and organic low molecular substance dispersed into said resin basic material and having transparency variable reversibly with temperature is provided onto one face of a transparent supporting material 1 in a thermal recording indicating material, and an organic resin layer 3 containing a silane compound is provided onto the other face. Resin basic material to be employed for the thermal layer 2 includes polyvinyl chloride; vinyl chloride - vinyl acetate copolymer, silicone resin, etc., having good transparency, good mechanical stability and good filming performance. The organic low molecular substance includes alkanol; alkanediol; halogen alkanol; halogen alkandiol, etc. Consequently, handwriting performance and erasability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-sensitive recording display material which performs recording and erasing by utilizing the reversible change in transparency of a heat-sensitive layer depending on temperature, and which is particularly useful as a display sheet for an electronic blackboard.

In conventional electronic blackboards, an image written by hand on a display sheet (called a whiteboard sheet) is optically read by photoelectric conversion means, and the read optical signal is converted into an electrical signal. This is taken out as the output of the printer attached to the electronic whiteboard to obtain a printout. However, on the contrary, an electronic blackboard that has the function of displaying an image written on a normal sheet of paper on a display sheet, for example, has not yet been developed. There is a small idea of an electronic blackboard equipped with an inkjet device (Japanese Patent Application Laid-Open No. 61-47300), but it is not yet practical.

■-1'' The purpose of the present invention is to write an image by hand on the surface of a display sheet, take out and record this image as a printer, and in addition to the function of a conventional electronic blackboard, 1) record it on a manuscript, magnetic recording medium, etc. This heat-sensitive recording display material is suitable as a display sheet for an electronic blackboard, which has the function of displaying a printed image on the display sheet surface using electrical signals, and is particularly designed to improve handwriting and erasability. It is to provide.

1-1" The heat-sensitive recording display of the present invention, as shown in FIG. It is characterized in that it is provided with a heat-sensitive layer 2 whose transparency changes reversibly depending on the temperature, and a silane compound-containing resin layer 3 provided on the other surface.

The recording principle of the display of the present invention utilizes the change in transparency of the heat-sensitive layer due to temperature, and this will be explained with reference to the drawings. In FIG. 2, the heat-sensitive layer is in a cloudy, opaque state at a room temperature of T0 or higher, for example.

When heated to a temperature between 11 and 72, it becomes transparent,
In this state, even if the temperature is returned to room temperature above T0, it remains transparent. Further heating to a temperature of T1 or higher results in a translucent state intermediate between maximum transparency and maximum opacity. Next, when this temperature is lowered, the liquid returns to its initial cloudy and opaque state without becoming transparent again. In addition, this opaque state is 7
After heating to a temperature between 0 and 71, room temperature, i.e. T.

When cooled to temperatures below, it can assume a state between transparent and opaque. Moreover, if the above-mentioned material that becomes transparent at room temperature is heated again to a temperature of 13 or more and returned to room temperature, it will return to a cloudy, opaque state. That is, the rain can take on opaque and transparent rain forms, as well as intermediate states thereof, at room temperature.

Thus, for example, after heating the entire layered heat-sensitive member having such a heat-sensitive layer to a temperature between 11 and 72T. A white image is formed by cooling to the room temperature below to make it transparent, and then partially heating it to a temperature of T1 or higher using a thermal head or the like to make that part opaque. If a colored member is placed on the back side of a layered heat-sensitive member having such a white image, this image can be recognized as a white image against the background of the color of the colored member.

On the other hand, after the entire layered heat-sensitive member is heated to a temperature of T1 or higher, it is returned to room temperature of T0 or higher and becomes cloudy and opaque, and then heated partially to a temperature of 11 to 72 using a thermal head etc. to make the part transparent. A transparent image is then formed on the white surface. If a colored member is placed on the back side of a layered heat-sensitive member having a transparent image as shown in 2, this image can be recognized as an image of the color of the colored member against a white background.

Recording and erasing on the layered heat-sensitive member as described above can be repeated at least 104 times.

In addition, by providing a silane compound-containing layer on the opposite side of this layered heat-sensitive member, it is possible to hand-write letters, images, etc. in various colors on this member using an oil-based pen, etc., and it is also possible to easily write letters, images, etc. on this member using a cloth, etc. can be erased.

Next, materials and forming methods used for each layer of the display of the present invention will be explained.

First, the resin base material used for the heat-sensitive layer is a material that forms a film or sheet in which a low-molecular-weight organic substance is uniformly dispersed and holds, and also influences the transparency at maximum transparency. Therefore, the resin base material is preferably a resin that has good transparency, is mechanically stable, and has good film-forming properties. Such resins include polyvinyl chloride; vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride acrylate copolymer Vinylidene chloride copolymers such as vinylidene chloride-vinyl chloride copolymers, vinylidene chloride-acrylonitrile copolymers, etc.; polyesters; polyamides; polyacrylates or polymethacrylates or acrylate-methacrylate copolymers, silicone resins, etc. It will be done. These may be used alone or in combination of two or more.

On the other hand, the organic low-molecular substance may be appropriately selected depending on the temperature T0 to T3 shown in FIG.
00°C, particularly preferably about 50 to 150°C.

Such organic low molecular substances include alkanol; alkanediol; halogenalkanol or halogenalkanediol; alkylamine; alkane; alkene; alkyne; halogenalkane; halogenalkene, halogenalkyne; cycloalkane; cycloalkene; cycloalkyne; saturated or Unsaturated mono- or dicarboxylic acids or their esters, amides, or ammonium salts; Saturated or unsaturated halogen fatty acids or their esters, amides, or ammonium salts; Allyl carboxylic acids or their esters, amides, or ammonium salts; Halogen allyl carboxylic acids or their esters, amides, or ammonium salts; Acids or their esters, amides, or ammonium salts; thioalcohols; thiocarboxylic acids or their esters, amines, or ammonium salts; carboxylic acid esters of thioalcohols, and the like. These may be used alone or in a mixture of two or more. The carbon number of these compounds is 10-60
, preferably 10-38, particularly 10-30.

The alcohol group moiety in the ester may be saturated or unsaturated, or may be substituted with halogen. Both are one kind, for example -OH, -
C00H, -CONH, -COOR, -NH-.

Compounds containing -NH2, -8-, -5-8+, -〇-, halogen, etc. are preferred.

More specifically, these compounds include higher fatty acids such as lauric acid, dodecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, behenic acid, nonadecanoic acid, arachidic acid, and oleic acid; methyl stearate, and tetradecyl stearate. , esters of higher fatty acids such as octadecyl stearate, octadecyl laurate, tetradecyl palmitate, tocosyl behenate; C-GH33
-Shizu, H, bar Hzs-5<1HssCzsHzt-5
Sound. Hll, HezHzs-S-C-J□ et al. 5-5-C
s-Has, et al., H2, -5-5 Ning 2H25CH.

There are ethers and thioethers such as

The weight ratio of the organic low-molecular substance to the resin base material in the heat-sensitive layer is preferably about 1:0.5 to 1=16. If the ratio of the resin base material is less than this, it will be difficult to form a film that retains the organic low molecular weight substance in the resin base material, while if it is higher than this, the amount of the organic low molecular weight substance will be small and the film will become opaque. It becomes difficult to

The above-mentioned heat-sensitive layer is usually formed by coating and drying a heat-sensitive layer forming liquid containing a resin base material and an organic low-molecular substance on a transparent support. Good too.

Such a heat-sensitive film or sheet is obtained by kneading a resin base material and an organic low-molecular substance in the presence or absence of a solvent, with heating if necessary, and forming and cooling the mixture into a film or sheet. Here, the heat-sensitive layer forming liquid is a solution in which both the resin base material and the organic low-molecular substance are dissolved in a solvent, or a solution in which only the resin base material is dissolved (the solvent is selected that does not dissolve the organic low-molecular substance). It is made by crushing and dispersing organic low-molecular substances in various methods. Note that, of course, when a dispersion is used, but also when a solution is used, the organic low molecular weight substance exists in a dispersed state as fine particles in the heat-sensitive layer obtained. The thickness of the heat-sensitive layer, heat-sensitive film or sheet thus formed is 5 to 50 μm.
About m is preferable. Opaque (whiteness) below 5μm
If the thickness is 50 μm or more, the transparency will be insufficient, and the contrast will decrease in both cases.

A plastic film, a glass plate, etc. are used as the transparent support. These may be colored.

On the other hand, the silane compounds used in the silane compound-containing resin layer include vinyl groups and epoxy groups.

Examples include the following compounds having reactive groups such as methacrylic groups and amino groups.

(Hereinafter, blank spaces) Examples of resins used in combination with these silane compounds include polyester resins, fluororesins, and the like. The content of silane compound in this resin layer is 0 per 1 part by weight of resin.
．． 01 to 0.15 parts by weight is suitable.

The silane compound-containing resin layer is formed by applying a solution containing a silane compound and a resin to the surface of the transparent support opposite to the heat-sensitive layer, and then thermally curing the solution. Incidentally, in order to further improve the writability, an inorganic filler such as TiO2, talc, CaCOa silica, alumina, etc. can be added to this solution. The thickness of the silane compound-containing resin layer thus formed is 0.
The thickness is preferably about 2 to 30 μm. If the thickness is 0.2 μm or less, it is difficult to form a uniform film, and if the thickness is 30 μm or more, the transparency decreases.

The present invention will be explained below by way of examples. Note that all parts are parts by weight.

Example 1 Polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) 27
of vinyltris (β-
Dissolve 3 parts of methoxyethoxysilane and add 100%
After coating on the surface of a polyester film having a thickness of μ, it was thermally cured at 130° C. to provide a silane compound-containing resin layer having a thickness of 10 μ.

Next, components consisting of 5 parts of stearic acid and 75 parts of tetrahydrofuran were mixed, uniformly dissolved and applied to the opposite side of the cyanide-containing resin layer, dried at 65°C, and 10μ
A thick heat-sensitive layer was provided and a completely transparent heat-sensitive recording display body was obtained.

Next, the heat-sensitive layer surface of the display body was placed on the black colored film so that it was in contact with the display body, and when printing was performed from the display body side using a thermal RAD, a clear white image was formed against a black background.

Next, the entire surface of the heat-sensitive layer of this display was heated to 65° C. and then cooled to room temperature, and the white image portion became transparent.

Then, in the same manner as above, a black colored film was overlaid and printing was performed using a thermal head, and a clear white image was formed against a black background. Furthermore, when writing and erasing were repeatedly performed on the silane compound-containing resin layer with an oil-based pen, excellent writing and erasing properties were exhibited without producing any erasing residue.

Example 2 A heat-sensitive recording display was produced in the same manner as in Example 1, except that 8 parts of titanium oxide was further added to the silane compound-containing resin layer forming liquid.

Using this display, printing with a thermal head, writing and erasing properties were tested in the same manner as in Example 1, and as in Example 1, excellent print recording properties, writing and erasing properties were shown.

Example 3 Vinyltris (β-
A heat-sensitive recording display was prepared in the same manner as in Example 1, except that γ-(methacryloxypropyl)trimethoxysilane was used instead of methoxynidoxin)silane.

Using this display, printing with a thermal head, writing, and erasing properties were tested in the same manner as in Example 1. As in Example 1, it showed excellent print recording properties, writing, and erasing properties.

Comparative Example Instead of providing a silane compound-containing resin layer with a thickness of 10 μm,
A heat-sensitive recording display was made in the same manner as in Example 1, except that a μ-thick fluororesin film was laminated to a polyester film.
The printing, writing, and erasability tests using the thermal head were conducted in the same manner as in Example 1. In the printing test,
The same results as in Example 1 were obtained, but the writing and erasing properties were inferior to those in Example 1.

As described above, the heat-sensitive recording display body of the present invention has a heat-sensitive layer that allows reversible recording and a silane compound-containing resin layer that allows writing and erasing. In addition to the function of writing an image by hand on the surface of the display sheet and then extracting and recording this image as printer output, it is also possible to display images recorded on manuscripts, magnetic recording media, etc. on the surface of the display sheet using electrical signals. It has the advantage that it is not only suitable as a display sheet for an electronic blackboard, but also has excellent handwriting and erasability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of the heat-sensitive recording display body of the present invention, and FIG. 2 is an explanatory diagram of the principle of recording and erasing in the heat-sensitive layer of this display body.

Claims (1)

[Claims] 1. On one side of the transparent support, the main components are a resin matrix and an organic low-molecular substance dispersed in the resin matrix,
A heat-sensitive recording display body comprising a heat-sensitive layer whose transparency changes reversibly depending on temperature, and a silane compound-containing resin layer on the other side.