JPS58168596A - Copying sheet - Google Patents

Abstract

PURPOSE:To provide a transfer sheet enabled in simple, safe and accurate transfer and facilitated in the reading of a transferred letter, consituted from a carbon transfer sheet having a carbon ink layer containing a specific amount of fatty amide and a carbon receiving layer. CONSTITUTION:A mixture consisting of a colorless-light colored electron donating org. compound [e.g., 3,3-(P-dimethyl-aminophenyl-6-dimethyaminophthalide)] or a phenolic hydroxyl group containing compound (e.g., bisphenol A) and 3- 80wt% pref., 5-50wt% fatty amide (e.g., stearyamide) solid at a room temp. is melted to be applied to a substrate sheet such as paper and the obtained coating layer is solidified by cooling to obtain a carbon transfer sheet 1 having a carbon ink layer 3 formed thereon. In the next step, the obtained sheet is combined with a carbon receiving sheet 2 having a fine random embossed pattern applied thereto to obtain desired copying sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying sheet for copying potentially hidden characters, symbols, etc. that develops color and becomes legible upon contact with an electron-donating organic compound or a phenolic hydroxyl group-containing compound. .

Reflecting the information age, in various fields of society there is a need to copy and transmit confidential information such as confidential texts and codes that would pose a problem if read and obtained by others or other parties. are very common.

One possible way to easily meet these demands is to utilize a coloring system consisting of an electron-donating organic compound and a phenolic hydroxyl group-containing compound, which has been widely used in pressure-sensitive copying paper, thermal copying paper, etc. . That is, for example, characters transferred from a transfer layer containing microcapsules of a colorless electron-donating organic compound solution to general paper are colorless and illegible, but when a phenolic hydroxyl group-containing compound solution is applied thereon, the characters develop color. , can meet the above request.

However, in the above-mentioned embodiment that directly applies the principle of pressure-sensitive copying paper, etc., since the electron-donating organic compound is dissolved in a solvent, the transferred characters etc. bleed during color development and are difficult to read. In some cases, information such as small letters and symbols may be transmitted incorrectly, leading to unexpected accidents.
There is a risk of causing damage.

The present inventors have solved the above-mentioned problems simply and easily by using a carbon ink prepared by blending fatty acid amide, which is solid at room temperature, with an electron-donating organic compound or a phenolic hydroxyl group-containing compound as a transition layer. The present invention was completed by determining that the present invention can be met in an appropriate manner.

That is, the present invention, as shown in the schematic longitudinal cross-sectional view of FIG.
A copy consisting of a carbon transfer sheet (1) and a carbon receiving sheet (2) having a carbon ink layer (3) containing a colorless or light-colored electron-donating organic compound or a phenolic hydroxyl group-containing compound and a fatty acid amide that is solid at room temperature. Regarding (A).

The colorless or light-colored electron-donating organic compounds used in the present invention include those conventionally used in pressure-sensitive copying papers, such as triphenylmethane phthalides, fluorans, phenothiazines, indolphthalides, and leukoola. They may be appropriately selected from mins, spiropyrans, rhodamine lactams, etc., and are not particularly limited.
．． 3-bis-(p-dimethylaminophenyl)-6-dimethylaminophthalide (this is the most useful L3,3-bis-(p-dimethylaminophenyl)-phthalide, rhodamine B lactone, 3-dimethylamine-6- Medoxyfluorane, 3,6-dinitoxyfluorane, 1,2-hency 6-dinithylaminofluorane, di-β-naphtho-spiropyran, xantho-β-naphtho-spiropyran, benzo-β-naphtho-iso Examples include spiropyran, any mixture thereof, and the like.

The colorless or light-colored phenolic hydroxyl group-containing compound used in the present invention is not particularly limited, but preferred examples include 4-t-butylphenol, 4-oxydiphenyl ether, β-naphthol, methyl p-oxybenzoate, 2.
2'-methylenebis(4-methyl-6-t-isobutylphenol), p-phenylphenoloxy-1-naphthoic acid, zinc salicylate, zinc salt of salicylic acid polymer, gallic acid, propyl gallate, and any of these Examples of fatty acid amides that are solid at room temperature according to the present invention include amides of caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, aragidic acid, behenic acid, and oleic acid; Any mixture is exemplified.

In this way, fatty acid amides are also waxy substances, but
It is distinguished from the general waxes described below because it significantly increases the solubility and dispersibility of the electron-donating organic compound' or phenolic hydroxyl group-containing compound in the molten state.

The amount of fatty acid amide that is solid at room temperature is usually 3 to 80 parts by weight, preferably 5 to 50 parts by weight.

The carbon ink according to the present invention may optionally contain colorless or light-colored waxes, i.e., waxes or waxy substances having a melting point of about 30 to 130°C, such as carnauba wax, Auricarry wax, 4 Candelilla wax, and Sugar Cane wax. , coconut wax, Sasol wax, oxidized ma.f. black wax, rice wax, paraffin (Q [11 or more)], low molecular weight polyethylene, wood wax, petrolatum, stearic acid, palmitic acid,
Stearic acid imide, stearone, etc. may be blended as appropriate.

The wax-type carbon ink prepared from the above-mentioned ingredients may be appropriately blended with an additive oil such as mineral oil or non-drying vegetable oil (usually about 0 to 50% by weight) to plasticize it and improve transferability. .

The carbon transfer sheet according to the present invention is produced by melting the above-mentioned carbon ink at a temperature higher than its melting point, preferably at a temperature about 10° C. higher than its melting point, to produce a base sheet, for example, paper.
It is generally manufactured by the so-called cold set method, in which it is coated or spot printed on cellophane, plastic film, etc., and immediately cooled to solidify and set.

The carbon transfer sheet thus obtained is used in combination with a carbon receiving sheet.

The carbon receiving sheet used in the present invention may be made of any material or form as long as it can potentially conceal and receive the carbon ink that is transferred by the pressure applied to the carbon transfer sheet. is commonly used.

In addition, if a fine random embossed pattern is applied to the carbon receiving sheet using a conventional method, it has the advantage of improving concealment by camouflaging the indentation of printed characters that would otherwise become legible due to localized strong pressure during transfer. .

Carbon ink IK on the carbon transfer sheet The carbon ink layer corresponding to the pressure area is placed on the receiving note by stacking the above carbon receiving sheets and applying pressure such as writing pressure or typewriter pressure from the transfer sheet side. transcribed in a potentially hidden state (unreadable to the naked eye);
A phenolic hydroxyl group-containing compound solution or an electron-donating organic compound solution dissolved in a solvent, particularly an aromatic volatile solvent such as toluene, xylene, trichlene, perchlorene, methylene chloride, 1, 1, 1-trichloroethane, etc., is applied to this transfer surface. When contacted by a method such as spraying or coating, the transferred area develops a readable color.

Furthermore, if two or more copies are required, the required number of transfer sheets may be inserted between the transfer sheet and the receiving sheet.

The copy sheet according to the present invention is extremely useful in various fields because it allows secret information to be transmitted simply and safely and accurately.

The present invention will be explained below with reference to Examples. In the examples, "part" means "single removal part".

Example 1 From 120 parts of salicylic acid polymer, 60 parts of basic zinc chloride, 250 parts of stearic acid amide, 200 parts of stearic acid, 615.0 parts of Bequist wax, and 32.0 parts of paraffin wax (melting point 135°F). The mixture consisting of
m' coating to obtain carbon transfer paper.

Layer the carbon transfer paper with the coated side facing down on the carbon receiving paper, which has a fine random embossed pattern on high-quality paper using a conventional method, and then write on the carbon transfer paper with a ballpoint pen to create a concealment that is completely unreadable to the naked eye on the carbon receiving paper. The characters were printed.

On the other hand, 3,3-bis-(p-dimethylaminophenyl)
-6~dimethylaminophthalide5. When a developer solution prepared from Om, 45.0 parts of methylene chloride and 500 parts of 1,1.1-trichloroethane was applied onto the hidden characters using a brush, the hidden characters developed a blue color and were unreadable. Ta.

Example 2 3.3-bis-(p-dimethylaminophenyl)-6-
8 parts dimethylaminophthalide, 32 parts stearamide
1 part of stearic acid, 15 parts of Hoechst wax 0, 15 parts of #1 carnauba wax, and 10 parts of paraffin wax (melting point 130°F).
Approximately 4 g/m on Indy 7 paper while heating to 'o'
Carbon transfer paper was obtained by coating. In the same manner as in Example 1, loose characters that were completely unreadable to the naked eye were printed on carbon receiving paper with an embossed pattern.

On the other hand, when a developing pot ψazol prepared from 5 parts of bisphenol A and 95 parts of hydrene was sprayed onto the hidden characters, the hidden characters developed a blue color and were legible.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional view of a copying sheet according to the present invention. . (1) is a carbon transfer sheet, (2) is a carbon receiving sheet, (3) is a carbon ink layer, and (A) is a copy sheet.
Indicates the

Claims (1)

[Scope of Claims] 1. A copying sheet comprising a carbon transfer sheet and a carbon receiving sheet, each having a carbon ink layer containing a colorless or light-colored electron-donating organic compound or a phenolic hydroxyl group-containing compound and a fatty acid amide that is solid at room temperature. 2 Content of fatty acid amide is 3 to 80% by weight, especially 5 to 80% by weight
50% by weight of the copying sheet according to claim 1. 3. The copying sheet according to item 1, wherein the carbon receiving sheet is a sheet with a fine random embossed pattern.