JPS60116491A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material free of coloring of ground or lowering in color forming performance with time and excellent in stability after color development, by using a novel fluoran derivative as a dye precursor for a black color forming recording material. CONSTITUTION:A fluoran derivative of the formula, wherein R1 is an amine residue, each of R2 and R3 is a hydrogen atom, by alkyl group or an aryl group, Ar is an aryl group, and eacc of Y and Z is a hydrogen atom, a halogen atom or a lowe alkyl group, is synthesized by, e.g., bringing 2-(2-hydroxy-4-subst. aminobenzoyl)benzoic acid and 2-aryl-4-alkoxy-N-subst. aniline into condensation in the presence of an acid catalyst. The fluoran derivative is applied to a base in a microencapsulated form to obtain a pressure-sensitive paper, or is applied to a base together with an electron-acceptive substance, a heat-fusible substance or the like to produce a thermal recording paper.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a recording material containing a novel fluoran derivative.

The fluoran compound according to the present invention is an extremely useful compound particularly as a dye precursor for various recording materials such as pressure-sensitive paper, thermal paper, and electrically conductive thermal paper.

It is also a compound that can be applied to photosensitive recording sheets, ultrasonic recording sheets, electron beam recording sheets, electrostatic recording sheets, ballpoint pen inks, crayons, etc.

<Prior Art> The use of various fluorane derivatives as dye precursors for pressure-sensitive or thermal papers is already well known and is described in US Pat. 4I32, West German Patent Publication (OLS) 1, 21,2.

No. 727 and Japanese Patent Publication ZI-3TR Copt. None of the color images obtained from these known fluoran derivatives are true black, and the fluoran compound itself is unstable in the atmosphere, and the dyes produced are not fast to light, moisture, etc. It had disadvantages such as being inferior.

<Objective of the Invention> Therefore, an object of the present invention is to provide a novel fluorane derivative which is particularly excellent as a dye precursor for black color recording materials.

<Structure of the Invention> The object of the present invention has been achieved by a fluoran derivative characterized by having an amine residue at the 2-position, an aryl group at the 3-position, and an amine/residue at the 6-position.

In particular, the heat-sensitive recording material containing the fluoran derivative of the present invention exhibits excellent performance, with little discoloration of the background and very little deterioration in coloring performance due to aging during storage.

Among the fluoran derivatives according to the present invention, preferred ones are represented by the following general formula.

In the above formula, -R1 represents an amine residue, R2 and R3 each may be the same or different and represent a hydrogen atom, an alkyl group, or an aryl group, Ar represents an aryl group, Y and Z represent a hydrogen atom, a halogen atom.

Or represents a lower alkyl group.

Among the amine residues represented by R1 in the above general formula, primary or secondary amine residues having a total carbon number of it or less are preferable, particularly diethylamino, dibutylamino, dioctylamino, diethylamino, N-ethyl-N-p -) lylamino, N-methyl-N-cyclohexylamino, piperine, benzylamino, toluidino, N-ethyl-N-
Isoamylamino, p-ethyltoluidino, and cyclohexylamino groups are preferred.

Among the substituents represented by R2 and R3, a hydrogen atom,
An alkyl group having a carbon atom number/lr or less and an aryl group having a carbon atom number t to 7.2 are preferable, and in particular a hydrogen atom,
Alkyl group having io or less carbon atoms, and 6 carbon atoms
-IO aryl groups are preferred.

The alkyl group and aryl group represented by R2 and R8 may have a substituent, and examples of the substituent include a halogen atom, an aryl group, an alkoxy group, an aryloxy group, a cyano group, and an acyl group. .

Among the aryl groups represented by Ar, aryl groups having 1 or less carbon atoms are preferable, and phenyl groups, tolyl groups, xycl groups, and halogen-substituted phenyl groups are particularly preferable.

Among the substituents represented by Y and Z, a hydrogen atom, a chlorine atom, a methyl group and an ethyl group are preferred.

The two fluoran derivatives according to the present invention are both new compounds, and have the advantage of being colorless or light-colored crystals with high solubility in organic solvents, and quickly developing a black color when they come into contact with electron-accepting substances. be. The developed pigment is significantly more stable than pigments produced from existing coloring agents, and can withstand long periods of light irradiation and heating.

It is particularly advantageous in terms of long-term preservation of records, as it hardly causes any discoloration even when humidified. In addition, the stability of the coloring agent is excellent, and even after long-term storage, there is no deterioration or discoloration, and the product has sufficient coloring ability.

It has near-ideal performance as a coloring agent for recording materials such as pressure-sensitive paper and thermal paper.

Representative examples of the fluoran derivatives according to the present invention include the following compounds.

(1) -2-Diethylamino-3-phenyl-t-diethylaminofluorane (21,2-dibutylamino-3-phenyl- -ter-diethylaminofluorane (3) 2-octylamino-3-phenyl-t- Diethylaminofluorane (4) -2-butylamino-3-phenyl-4-diethylaminofluoran (5) 2-benzylamino-3-phenyl-t-diethylaminofluorane (6) -2-β-phenylethylamino- 3-phenyl-t-diethylaminofluoran (7) 2-butylamino-3-phenyl-t-dibutylaminofluoran (8) 2-anilino-3-phenyl-t-dibutylaminofluoran, and the like.

<Method for Synthesizing Fluoran Compound> Next, a method for synthesizing the fluoran derivative according to the present invention will be described.

The fluoran derivative according to the present invention can be synthesized by various methods, but the following two are typical synthetic methods.

Synthesis method: A condensation reaction of 2-(,2-hydroxy-gu-substituted ami-6-nobenzoyl)benzoic acid and λ-aryl≠-alkoxy N-substituted aniline in the presence of an acid catalyst Synthesis method 2: 2-Amino-3-aryl-t-substituted aminofluorane and an alkylating agent or arylating agent as required in a solvent.

and/or react in the presence of an additive to alkylate or arylate the 2-position amine group. Acid catalysts used in Synthesis Method I include Lewis acids such as zinc chloride, aluminum chloride, magnesium chloride, and calcium chloride; sulfuric acid, p-toluenesulfonic acid,
Bronsted acids such as methanesulfonic acid are used.

Alkylating agents in the synthesis method include alkyl halides and alkyl sulfonic acid esters.

Alkyl-p-toluenesulfonic acid esters, etc. are used, and as the arylating agent, halide aryl-p-)toluenesulfonic acid esters are used.

Solvents used as necessary in the synthesis method include common organic solvents such as methanol, ethanol, isopropanol, methyl cellosolve, ethyl cellosolve, benzene, toluene, xylene, dimethylbormamide, acetone, and methyl ethyl lactone. can be given.

In addition, additives include potassium carbonate, sodium carbonate,
Magnesium oxide, calcium oxide, triethylamine, potassium iodide, potassium bromide.

Sodium iodide, sodium bromide, tetraphtylammonium iodide, tetrabutylammonium bromide, iodine, copper powder, copper oxide, cupric iodide.

Examples include cupric iodide, nickel compounds, and cobalt compounds.

Next, a specific example of synthesis of the fluoran derivative according to the present invention will be shown.

Synthesis Example 1 Synthesis of λ-β-phenylethyl-3-enyl-t-diethylaminofluorane λ-(2-hydroxy-
≠-diethylaminobenzoyl)benzoic acid 4. ,? ,9
-λ-β-phenylethylamino-j-methoxybiphenyl t, og.

and concentrated sulfuric acid/jml was stirred at 00C for 3 hours, then at room temperature for 2 hours, and then at room temperature for an additional hour aooc.

After cooling, pour one reaction solution into ice water and hydroxylate.) Neutralize with IJ and extract with ethyl acetate. After distilling off the solvent from the extract, the residue was purified with a silica gel column using chloroform-methanol as a solvent. Purified to give 2-β-phenylethylamino-3-phenyl-&-diethylaminofluorane 4'
, 011 (melting point ///-7lj0C) was obtained.

Synthesis Example 2 Synthesis of λ-amy-J-phenyl-6-dinithylaminofluorane λ-(2-hydroxy-≠-diethylaminobenzoyl)benzoic acid 4. ．． A mixture of 2,9, co-amino-methoxybiphenyl a, og and h[ILE acid/jd was reacted and purified in the same manner as in Synthesis Example 1.

-monoamino-3-phenyl-butydiethylamino? - Fluorane 3. rfl (melting point 17 ter/ther, 2°C) was obtained.

Synthetic glue 3 λ-amino-3-phenyl-4-diethylaminofluorane//g, diethyl sulfate/Ig, potassium carbonate 23g
A mixture of 10011 and toluene was stirred for 70 hours while heating and refluxing. After cooling.

The reaction solution was poured into ice water and extracted with ethyl acetate. The solvent was distilled off from the extract, and the residue was purified with a silica gel column using hexane-ethyl acetate as a solvent.

10.79 of λ-diethylamino-3-phenyl-t-diethylaminofluorane (melting point 1ro-/jco'c) was obtained.

Next, a specific method for producing a recording material using the dye precursor according to the present invention will be described.

Pressure-sensitive paper using the dye precursor of the present invention is disclosed in U.S. Pat.
, 101 , ≠ No. 70, same, 101 , $7/l
Same 2,10! , 4AI No. 9, same, Sat.

No. 344, same, 7/2, No. 107, same, 2173o,
4tta No., No. 730.4117, No. 31
It can take various forms as described in 10-≠it, No. 2to, etc. That is, the above-mentioned dye precursors may be used alone or in combination, or together with other dye precursors in a solvent (synthetic oil such as alkylated naphthalene, alkylated diphenyl, styrene dimer, diphenylalkane, alkylated terphenyl, chlorinated paraffin, etc.). After dissolving it in vegetable oil such as soybean oil, castor oil, animal oil, mineral oil, or mixtures thereof, it can be dispersed in a binder or contained in microcapsules, and then processed into paper, plastic sheets, resin-coated materials. It can be obtained by applying it to a support such as paper. The dye precursor of the present invention particularly has the advantage of being soluble in the above-mentioned solvents at high concentrations.

The amount of the dye precursor to be used varies depending on the desired coating thickness, the form of the pressure-sensitive paper, the capsule manufacturing method, and other conditions, and may be appropriately selected depending on the conditions. In encapsulating dye precursors, U.S. Patent No. λ, 100. ≠! No. 7 and 2
, 100, method using coacervation of hydrophilic colloid sol described in Hiroo No. 1, British Patent No. 147.727, British Patent No. 210. ≠≠Specification No. 3.

The interfacial polymerization method described in the specification of the same No. 1,0/074 can be used.

Next, a general method for producing thermal paper using the dye precursor of the present invention will be described.

Sufficiently add a dye precursor, an electron-accepting substance, and a thermofusible substance (used when the dye precursor or electron-accepting substance does not melt at the desired temperature) to a liquid in which the binder is dissolved or dispersed in a solvent or dispersion medium. Finely grind and mix into paper and plastic sheets.

It can be obtained by coating and drying on a support such as resin-coated paper. When preparing a liquid mixture, all the components may be mixed and pulverized at the same time from the beginning, or they may be combined in appropriate combinations, pulverized and dispersed separately, and then mixed.

Further, the coating liquid may be poured into the support.

Furthermore, an opacifying agent may be added and mixed during mixing.

The amounts of each component constituting the thermal paper are: 1 dye precursor/~λ parts by weight, electron-accepting substance/-4 parts by weight, thermofusible substance θ~3 parts by weight
0 parts by weight, pigment θ~/j parts by weight.

7 to 75 parts by weight of binder and 20 to 3 parts by weight of dispersion medium (solvent)
00 parts by weight.

As the dye precursor, one or more of the fluoran derivatives of the present invention may be used as a mixture, or compounds known as color formers for pressure-sensitive paper such as crystal violet lactone and fluoran derivatives may be used with the fluoran derivative of the present invention. They may be used in combination. As an electron-accepting substance, 1
Among those mentioned at the beginning of the text, organic acids or metal salts thereof are particularly preferred.

Water is most desirable as the dispersion medium (solvent).

Examples of binders used in the present invention include styrene-butadiene copolymers, pulquid resins, acrylamide copolymers, vinyl chloride-vinyl acetate copolymers, styrene-maleic anhydride copolymers, synthetic rubbers, gum arabic, polyvinyl alcohol, hydroxy Examples include ethyl cellulose.

Especially gum arabic in relation to the dispersion medium (solvent).

l 3- polyvinyl alcohol, hydroxymethyl cellulose,
Water-soluble binders such as carboquine methylcellulose are preferred.

As a thermofusible substance, erucic acid is used as necessary.

Stearic acid, behenic acid, normitic acid, stearic acid amide, behenic acid amide, stearic acid anilide, stepric acid toluiside, N-myristoyl-p-anisidine-N-miIJ Stoyl-p-7enetidine, l-methoxycarbonyl-≠- N-stearylcarbamoylbenzene, N-octadecylurea, N-hexadecylurea, N,N'-didodecylurea, phenylcarbamoyloxydodecane, p-t-butylphenolphenoxyacetate, p-phenylphenol-p-chlorophenoxyacetate ), 4I, ≠'-isopropyritine bismethoxybenzene, β-phenylethyl-p-phenyl phenyl ether, λ-p-chlorobenzyloxina7talene, copenzyloxynaphthalene/, /-benzyloxynaphthalene, 2 -Phenoxyacetyloxynaphthalene.

-/≠- Phthalic acid diphenyl ester, /-hydroxy-λ-naphthoic acid phenyl ester, norpentyloxynaphthalene, p-benzyloxybenzoic acid benzyl ester, hydroquinone acetate, etc. are used.

These substances are colorless solids at room temperature.

It is a substance that has a sharp melting point at a temperature suitable for the heating temperature for copying, that is, around 70 to 100c. These are substances that dissolve at least one, preferably both, of the dye precursor and electron-accepting substance in the molten state.

In order to produce an electrically conductive thermal paper using the dye precursor of the present invention, the methods disclosed in Japanese Patent Application Laid-Open Nos. 1-3-1 and 3-0 are useful.

That is, a conductive substance is applied to a support such as paper, or a liquid in which a dye precursor and an electron-accepting substance are suspended or dispersed together with a binder in a dispersion medium such as water, or a conductive substance is applied onto a support to conduct the conductive substance. It is obtained by forming a layer and applying a liquid containing a dye precursor and an electron-accepting substance dispersed in water or the like together with a binder on the layer. The preferred temperature for both the dye precursor and the electron-accepting substance (generally 70~/300C)
), a thermofusible material that melts at a preferred temperature and dissolves at least one of the dye precursor or electron-accepting material can be added.

By doing so, the sensitivity to Joule heat caused by energization can be adjusted.

As the electron-accepting substance and the thermofusible substance, the same substances as those described in the method for producing thermosensitive recording paper can be used.

In order to produce a recording sheet using the dye precursor of the present invention, IP1 public show 3t-2 pivy, special public show l! -/01
10. %Koakira≠t-i3.2zt, Tokukoakira≠tar20≠
, JP Sho≠2-62/ko, JP Sho≠tar 2j≠mariri, JP Sho 7-37t/j, JP Sho≠l-32132, JP Sho≠tar 22 core, % Sho 4l-i3zti' y, JP-A ShojO-10/, 20, JP-A Sho 3'0-J'7J/7.
In place of dye precursors such as lactone compounds, lactam compounds, spiropyran compounds, carbinol compounds, ethylene compounds, leucoauramine compounds, oxazine compounds, etc. used in , produced by using the fluoran derivatives of the present invention.

Other recording materials can also be produced by using the fluorane derivatives of the present invention in place of conventional dye precursors.

<Examples of the invention> Example 1゜7 parts of the dye precursor of the present invention (compound of Synthesis Example 3) (
1. parts by weight of the alkylated naphthalene (the same applies hereinafter). was dissolved in one part. This solution was added to 10 parts of water in which gelatin part and gum arabic part was dissolved, with vigorous stirring, and emulsified to form oil droplets with a diameter of ≠μ to 6μ, and then 210 parts of water was added. Add acetic acid little by little to bring the pH to about ≠ to cause coacervation, create gelatin and gum arabic a around the oil droplets, and then add formalin.

The pH was raised to 2 and the walls were cured.

The thus obtained microcapsule dispersion l 7- was applied to paper and dried. This paper is treated with acidic organic substances, phenolic resin, +, +'-isopropylidenediphenol, 3.
! - Pressure is applied to paper coated with zinc di(α-titylbenzyl)salicylate, p-hydroxybenzoic acid benzyl ester, zinc nomiladruenesulfonate, 2,2'-methylenebis p-chlorophenol, etc. alone or in combination. When added, a black image was instantly obtained. This image had high density and excellent light resistance and heat resistance.

Example 2 Synthesis Example 1 was used as a coloring agent in place of the dye precursor in Example t.
The compound of 7. is also added to the solvent. /-using ditolylethane,
A microcapsule-coated paper was prepared in the same manner as in Example 1. A pressure-sensitive paper was obtained that developed color quickly and with high density, and had extremely excellent light resistance and heat resistance for characters that developed one color.

Examples & 30 parts of the dye precursor of the present invention (compound of Synthesis Example 3)
1:/10 parts of a 70% polyvinyl alcohol aqueous solution and 70 parts of water were mixed and ground using a ball mill for 1-/t-hours to prepare a dispersion. The particle size after crushing is approximately x
, r microns. (Component A) On the other hand, 30 parts of bisphenol A, 30 parts of stearic acid anilide, l! θ
10% polyvinyl alcohol aqueous solution and 15 parts water were mixed and ground using a sand mill to prepare a dispersion. The particle size of the insoluble material after pulverization was approximately 2 microns. (Component B) Next, 1 part of component A and 4IO parts of component B were mixed.

Thermal paper was obtained by applying it to paper and drying it.

This thermal paper turned black when heated with a heat source. Further, when this thermal paper was overlapped with the original image and heated with a thermal copying machine, a black copy image was obtained. The color image obtained was very stable against light, and even when the image was irradiated with an ultraviolet lamp for 7 hours, there was almost no change in either hue or density.

Patent applicant: Fuji Photo Film Co., Ltd.

Claims (1)

[Claims] A recording material comprising a fluoran derivative containing an amine residue at the 2-position, an aryl group at the 3-position, and an amine residue at the 3-position.