JPH0337974Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of the Invention) The present invention relates to a recording material, and particularly to a recording material that can quickly change or decolor a colored body by heating and can stably maintain that state.

(Prior Art) Conventionally, many types of recording materials that form colored images by heating have been proposed in a wide variety of fields. Furthermore, it is well known that some of them have already been put into practical use.

The present invention is designed to avoid the use of unreliable recording materials that fog over time, return to their original state when left unused, or become colored simply by being heated, unlike those conventional techniques. It makes a difference.

(Purpose of the invention) The present invention does not have the above-mentioned problems, but rather causes the colored portion to permanently change color, decolorize, or become transparent by heating. The present invention provides a completely new type of recording material capable of forming recording (monocolor) by heating, multicolor recording by revealing the underlying color, or transparent image.

(Structure of the invention) The purpose of the invention is to heat a support to a temperature of 60°C or higher in the vicinity of a layer in which a recording component - a component colored by an acid-base reaction - is substantially uniformly supported on, in, or above and below a support. When heated, it melts and creates a substance that has the function of inhibiting acid-base reactions, and when heated above 60°C, it permanently discolors or decolors the colored components in the heated area. This was achieved by developing recording materials that made this possible.

Here, "substantially uniformly supported" means that on the support,
Whether it is layered, striped, dotted, or fine arabesque in the support or above and below the support, it is coated to a level that allows it to be identified as a recording material, for example, to the extent that it has a resolution of 6 lines/mm or more. This includes those that have been prepared, vapor-deposited, transferred, or kneaded.

As for coloring using acid-base reactions, as is well known, a group of coloring agents called leuco compounds, PH indicators, etc. There is a group of combinations called leuco compounds, PH indicators, which are colored by combinations or inorganic or organic bases.

For example, phenolphthalein, leuco crystal violet, crystal violet lactone, pyridyl blue, 2-anilino-3-methyl 6-N-ethyl, N-isoamylaminofluorane, 3,6-bisdiphenylaminofluorane, There are compounds having one or more aromatic rings having amino, substituted amino or hydroxy such as triphenylmethane, xanthene, phthalide and spiropyran such as fluorescein.

Further, those having a melting point of 50° C. or higher, preferably 90° C. or higher are preferred from the viewpoint of handling and storage stability of the recording material.

These compounds produce colored bodies when they come into contact with or react with acidic or basic substances. In particular, combinations with organic acids or organic bases are preferred.

This coloring reaction is applied to pressure-sensitive paper, heat-sensitive paper, electrically conductive recording paper, and the like. In these methods, since both components, which are initially colorless, are colored by heating, there are problems such as coloring due to fog, undesirable coloring due to careless heating, pressurization, etc.

The present invention is completely free from these problems. The following two substances have the function of melting when heated to 60°C or higher and acting with one of the components that formed the colored object through an acid-base reaction to change, decolor, or make the colored object transparent. Broadly classified. In other words, it is a solid compound itself and melts when heated.
Substances that change the acidity or basicity of the immediate vicinity and decomposition reactions within or between molecules due to heating.
There are two types that cause elimination reactions and change the acidity or basicity of the vicinity.

Specifically, salts with organic acids, inorganic acids or weak bases,
These include salts with organic bases, inorganic bases, or weak acids.
As mentioned above, these include substances that generate acids or bases upon heating, so-called precursors. These are well known in the field of thermal development.

This is preferably a compound that has a melting point of 60°C or higher, preferably 80°C or higher, is stronger than the acid or base involved in the coloring reaction, for example, has a PKa or PKb different by at least 1, and is twice as strong as the colored component. It is desirable to use more than the amount. These are less than 10μ,
Preferably, it is used in a finely dispersed state of 3μ or less.
For example, bisphenol A, bisphenol S, resorcinol sulfide, hydroxynaphthalene sulfonic acid, methyl dihydroxynaphthalene sulfonate, 2,4-dihydroxybenzoic acid-β-phenoxyethyl ester, 2,4,6-
Trihydroxybenzoic acid benzyl ester, gallic acid phenethyl ester, tetrahydroxybenzophenone, gallic acid phenethyl amide, 3,5
-Zinc di-α-methylbenzylsalicylate, triethylamine toluenesulfonate, guanidine trichloroacetate, tritolylguanidine, tolylguanidine oxalate, ammonium toluenesulfonate, 5-methylbenzimidazole, N-
Examples include phenylimidazole, 2-phenylimidazole, carbonic acid, bicarbonate of soda, and the like.

In addition, a viscosity reducing agent, that is, a monoether, diether, or ester having a melting point of 70°C or higher, preferably 90°C or higher, such as phenyl 1-hydroxynaphthoate, β-benzylnaphthyl ether,
Diphenoxyethane, β-phenoxyethoxy
It is preferable to atomize p-ethylbenzene and the like and allow it to coexist.

The heating means may be direct heating such as a thermal head or a hot pen, or indirect heating such as a thermometer, laser light, or xenon lamp.

When a support is used, it is preferably a single layer or a smooth layered support, regardless of whether it is transparent, a white layer, or a colored layer. Which of these to choose depends on the application. In other words, do you want to save it as a single color?
It has the advantage of being able to be changed widely depending on the user's desired characteristics, such as whether to view in multiple colors, UV light, reflection, or transmission.

This point is also very different from conventional recording systems that can only be made opaque by coloring.

Further, as the support, paper, synthetic paper, high-quality paper, polyester film, aluminum plate, etc. are used. These supports can also have minute irregularities. In the field of photographic supports, there is a so-called silk texture. In particular, it is preferable that these supports have a smoothness of 100 sec or more. When kneaded into the support, thermoplastic polymers such as styrene-based and vinylidene chloride-based polymers having film-forming properties, such as vinyl-based polymers, are preferred.

Furthermore, it is also possible to provide a plurality of recording layers according to the present invention, to use an inorganic pigment together in order to impart printability when the surface of the support is a recording layer according to the present invention, or to add a part of the back surface or the front surface. It is within the scope of those skilled in the art to provide a magnetic recording layer on the magnetic recording layer.

[Brief explanation of the drawing]

FIG. 1 shows an example of a cross-sectional view of a recording material according to the present invention. In the figure, 1 indicates a layer containing a component colored by an acid-base reaction. 2 represents a layer containing a compound that releases a substance having the function of inhibiting acid-base reactions when heated. 3 indicates a support. FIG. 2 shows an example of a cross-sectional view of a recording material according to the present invention. In the figure, 1 indicates a layer containing a component colored by an acid-base reaction. 2 represents a layer containing a compound that releases a substance having the function of inhibiting acid-base reactions when heated. 4 indicates a support containing a dye or pigment. FIG. 3 shows an example of a cross-sectional view of a recording material according to the present invention. In the figure, 1 indicates a layer containing a component colored by an acid-base reaction. 2 represents a layer containing a compound that releases a substance having the function of inhibiting acid-base reactions when heated. 5 indicates a transparent support.

Claims (1)

[Scope of utility model registration request] A substance that melts when heated to 60°C or higher and has the function of inhibiting acid-base reactions is present on the support near a layer that substantially uniformly supports colored components through acid-base reactions. , a recording material that can discolor or erase the colored components in the heated area when heated to 60°C or higher.