JPH0469075B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a pressure-sensitive or heat-sensitive recording paper having a fluorane derivative as an electron-donating coloring agent in the support.

More specifically, the present invention relates to the general formula () (In the formula, R ¹ represents an n-propyl group or an i-butyl group, and R ² represents an i-butyl group.) Pressure-sensitive or heat-sensitive recording having a fluoran derivative represented by the following as an electron-donating coloring agent on a support. It's paper.

(b) Prior art Pressure-sensitive recording paper and heat-sensitive recording paper, which apply a coloring reaction caused by contact between an almost uncolored electron-donating substance and an almost uncolored electron-accepting substance, are very popular in today's information technology. Demand is increasing with the development of the times. Generally, pressure-sensitive recording paper is produced by dissolving an electron-donating white dye (hereinafter referred to as a coloring agent) in an organic solvent.
The top paper is emulsified into a few microns and microencapsulated with a polymer compound such as gelatin, and this is coated on a support, and the other side is coated with an electron-accepting substance (hereinafter referred to as a color developer) on the support. The coated surfaces of the two are placed opposite each other, and the microcapsules are destroyed by applying pressure such as pen pressure or striking pressure, and the coloring agent in the capsules is released and transferred to the coloring agent surface. , is a recording method that produces a color reaction to obtain a copied image. The most common type of thermal recording paper is one in which a finely divided color forming agent and color developing agent are supported in a binder (for example, a polymer material such as polyvinyl alcohol) so that the two do not come into contact with each other, and the paper is provided on a support. This is a recording method in which at least one of a color forming agent or a color developing agent is melted by heating and brought into contact, causing a coloring reaction to produce an image.

(c) Problems to be solved by the invention Although the demand for these recording papers is increasing with the development of the current information age, there is still a single black coloring agent that can produce a black image. At present, no material has been found that satisfies all aspects such as self-color development (background fogging), fastness, and cost. Furthermore, recently there has been an increasing demand for faster speeds in facsimile machines that use heat-sensitive recording paper, and there are great expectations for color formers that can produce high-density black images at high speed.

(d) Means for Solving the Problems The fluorane derivative represented by the general formula () used in the present invention itself is a colorless white crystal, but when brought into close contact with an electron-accepting substance, it becomes concentrated. It has been found that it is a coloring agent that develops a black or dark green color, has extremely excellent light fastness and water resistance, and has excellent background fogging properties, and is a useful pigment particularly suitable for high-speed facsimile. Ta.

The compound represented by the general formula () of the present invention is synthesized, for example, as follows.

General formula (A) (In the formula, R ¹ and R ² have the above-mentioned meanings.) An N-disubstituted m-aminophenol compound represented by the formula (wherein R 1 and R 2 have the above-mentioned meanings) is reacted with phthalic anhydride to obtain a general formula (
B) (In the formula, R ¹ and R ² have the above meanings.) (59.11.29 patent application) and the general formula () (In the formula, R represents hydrogen or an alkyl group having 1 to 4 carbon atoms) is condensed using a dehydration condensation agent such as sulfuric acid, and then, if necessary, heated or treated with an aqueous caustic alkali solution. After heat treatment with ethylene glycol, purification with an organic solvent yields white crystals.

Heat-sensitive or pressure-sensitive recording paper can be produced by a conventional method using one or more of the color formers thus obtained, or in combination with other color formers. Color developers commonly used at this time include bisphenols such as bisphenol A and cyclohexylidene bisphenol, phenylphenol, alkylphenols, oxybenzoic acids such as benzyl paraoxybenzoate, and esters of oxynaphthoic acid. phenols, formalin novolak resins of alkylphenols, sulfur chloride condensates of alkylphenols, zinc or calcium salts of salicylic acid and its derivatives, activated clays, clays, aromatic carboxylic acids and sulfonic acids and their metal salts, thio Examples include urea derivatives.

Also, the glue commonly used in the production of recording paper,
In addition to light stabilizers and lubricants, thermal paper generally uses a fluxing agent (sensitivity improver), and pressure-sensitive paper uses capsule materials and capsule solvents (high-boiling organic solvents that are insoluble in water). It is known.

(e) Actions and Effects The fluoran derivative represented by the general formula () used in the method of the present invention is a novel compound not described in any literature, and is suitable for pressure-sensitive or heat-sensitive recording paper produced in combination with the color developer. is particularly excellent in storage stability, color development, light resistance, and water resistance. In other words, recording paper using this color former,
2-anilino-3, a known black coloring compound
-Methyl-6-(N-diethylamino)fluoran, 2-(2'-chloroanilino)-6-(N-diethylamino)fluoran shows that in pressure-sensitive paper, the color change due to light of capsule-coated paper is less In addition, it has excellent light resistance and moisture resistance of colored images, and in thermal paper, it has excellent stability of the background and colored images against light, heat, and humidity, and is suitable for high-speed facsimile.

(f) Examples Next, the present invention will be specifically explained using examples.

Example 1 2-anilino-3-methyl-6-(N-diisobutylamino)fluoran (FD-MS M/Z=
532) Disperse 5 parts of a 10% hydroxyethyl cellulose aqueous solution and 15 parts of water using glass beads to obtain a dispersion with a particle size of 2 to 3 μm (referred to as solution A). 10 parts of bisphenol A, 10 parts of a 10% hydroxyethyl cellulose aqueous solution, and 30 parts of water are dispersed using glass beads to form a dispersion with a particle size of 2 to 3 μm (referred to as liquid B). In addition, powdered calcium carbonate
Prepare a dispersion of 20 parts of 5% methylcellulose and 60 parts of water (referred to as liquid C). 10 parts of A liquid, 20 parts of B liquid
and 30 parts of Solution C, and further added 10 parts of a 20% aqueous solution of isobutylene/maleic acid copolymer salt and mixed with stirring. The mixed solution was applied to 50 g/m ² high-quality paper using a wire bar so that the amount of adhesion after drying was 5 g/m ² and dried with warm air at 60° C. for 1 minute. When the thus obtained heat-sensitive recording sheet was printed at 150℃ using a thermal gradient tester at a pressure of 2Kg and a contact time of 1 second,
A deep black image was obtained. Furthermore, when used in a high-speed facsimile printer, the color sensitivity was excellent. The light fastness, water resistance, and plasticizer resistance of the black image area obtained by coloring and the uncolored background area were all extremely excellent.

In addition, as a coloring agent, 2-anilino-3-methyl-6-(N-isobutyl-N-propylamino)
Similar results were obtained using fluoran (FD-MS M/Z=518) using parahydroxybenzoic acid benzyl ester instead of bisphenol A as a color developer.

Example 2 2-anilino-3-methyl-6-(N-diisobutylamino)fluoran (FD-MS M/Z=
532) was dissolved in 100 parts of isopropylnaphthalene and added to a solution of 25 parts of gelatin, 25 parts of gum arabic, and 350 parts of water at 50°C to emulsify. Add warm water to this
Add 1000 parts and stir at 50°C for 30 minutes, then add 1 part of 10% caustic soda solution and stir at 50°C for 30 minutes. Adjust the pH of the solution to 4.5 by gradually adding dilute aqueous acetic acid solution,
After stirring for 1 hour at °C, cool to 5 °C and stir for 30 minutes.

After hardening the capsules by gradually adding 40 parts of a 5% aqueous glutaraldehyde solution, the pH is adjusted to 6 using dilute caustic soda solution and stirred at room temperature for several hours.
Next, add 30% of cellulose fine powder to this capsule emulsion.
45 parts, mix 100 parts of a 10% aqueous solution of oxidized starch,
g/m ² base paper to a coating weight of 5 g/m ² after drying and drying to obtain a top sheet of pressure-sensitive recording paper.

This upper sheet was stacked with the lower sheet coated with a color developer with the coated side aligned, and when pressure from a pen or typewriter was applied, the color developed black. In other words, the paper was coated with formalin novolac resin of phenol/alkylphenol on the surface, acid-treated activated clay and 3.5-bis(α-
Clear black letters appeared on both sheets of paper coated with the zinc salt of (methylbenzyl) salicylic acid.

The above-mentioned pressure-sensitive paper had good storage stability and fast coloring speed, the colored characters could withstand light for a long time, and had excellent water resistance and plasticizer resistance.

In addition, 2-anilino-3-methyl-
Similar results were obtained using 6-(N-isobutyl-N-propylamino)fluorane (FD-MS M/Z=518).

Claims (1)

[Claims] 1 General formula () (In the formula, R ¹ represents an n-propyl group or an i-butyl group, and R ² represents an i-butyl group.) A pressure-sensitive or heat-sensitive product having a fluoran derivative represented by the following as an electron-donating coloring agent on a support. Recording paper.