JPS6097887A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material excellent in color forming property and stability of developed color images, by using a specified arylaminofluoran derivative as a color former in a thermal recording material. CONSTITUTION:A coating liquid comprising 1-2pts.wt. of a fluoran derivative of the formula, wherein R1 is an arylcarbonyl-containing group, preferably, an arylcarbonylalkyl group, R3 is an amine residue, and each of R2, R4 and R5 is a hydrogen atom, a chlorine atom, an alkyl group or a subst. alkyl group, the group -COOR1 being preferably located at the ortho position with respective to the anilino group present at 2-position, as a dye precursor, 1-6pts.wt. of a phenol derivative, preferably, a compound having a phenolic hydroxyl group, 0- 30pts.wt. of a heat-fusible substance, 0-15pts.wt. of a pigment, 1-15pts.wt. of a binder and 20-30pts.wt. of a dispersant, is applied to a base, and is dried to obtain the recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording material, and more particularly to a recording material with improved color development and stability of color images.

Recording materials using electron-donating colorless dyes and electron-accepting compounds were published in Tokko Sho μs-i<to3 No. 3 and Tokko Sho 4 (J-
4/4θ, etc. The minimum performance that such recording materials should have is (1) sufficient color density and color development sensitivity, (2) no fogging (color development during storage before use), and (3) color development. The following requirements are that the color forming material has sufficient fastness, but currently no product has been obtained that completely satisfies these requirements.

Particularly in recent years, as recording systems have become faster, research on the above (1) has been intense. Regarding heat-sensitive recording materials, which are one type of recording material, the melting point of the electron-accepting compound itself may be increased from 10 to too'C. However, it is difficult to control the melting point of phenolic compounds, which are currently the most widely used electron-accepting compounds, and the phenolic compounds themselves are expensive and impractical.

Other methods include the combined use of an organic acid and a phenolic compound as an electron-accepting substance in JP-Kokoku Sho≠Tar 1774Ar and JP-Kokko J/-JRI 367, or the use of polyhydric compounds with alcoholic hydroxyl groups. The use of metal salts is described. Tokko Akira again! no lambda t
, No. tS describes the use of a copolymer of hydroxyethyl cellulose and maleic anhydride.

Furthermore, Japanese Patent Publication No. Shoj/-27j Tata and Japanese Patent Publication No. Sho1-/Tar 37 disclose the addition of waxes.

In addition, JP-A Showa tter 3≠rμ-, JP-A Show≠2-/1
333μ, JP-A-30-/Geta-353, JP-A-J-Ko-1067-G, JP-A-Jr3-jtJt, JP-A-Sho! ! -/No. 1034, JP-A-53-μZA-73/, and JP-A-Sho! Nitrogen-containing substances such as thioacetanilide, phthalonitrile, acetamide, di-β-naphthyl-p-phenyl diamine, fatty acid amide, acetoacetanilide, diphenylamine, penzamide, carbazole, etc. Addition of organic compounds or thermofusible substances such as Co, 3-di-m-tolylbutane, ≠, ≠′-dimethylbiphenyl, or carboxylic acid esters such as dimethyl isophthalate, diphenyl phthalate, dimethyl terephthalate, etc. as sensitizers. It is stated that Also, British Patent Publication No. 2.07μ, J
No. szk describes the addition of hindered phenols.

However, heat-sensitive recording materials produced using these methods are insufficient in terms of color density and color sensitivity.

In addition, many methods to improve the stability of color images have been researched, including the
It is known in Japanese Patent Application Publication No. 2003-12001 that a phenol derivative such as J, 2'-)Itinbis(4A-methyl-6-tert-butylphenol) can be added to the number. 3-/73177
JP-A-Sho! No. 2009-2011, it is possible to add a water-insoluble modified phenolic resin such as rosin-modified resin to the No. 1 issue. No. 1-722PJ describes the addition of terephthalic acid ester.

However, all of the heat-sensitive recording materials produced using these methods have insufficient image stability.

Therefore, an object of the present invention is to provide a heat-sensitive recording material which has good color development properties and stability of color images, and which satisfies other requirements.

The object of the present invention has been achieved by a heat-sensitive recording material characterized in that it contains an arylaminofluorane derivative and a phenol derivative in which the ortho position is very specific at the 2-position. The reason why the recording material of the present invention has a high color development rate and good storage stability is probably due to the improvement in dissolution rate and compatibility due to the presence of an ester group having an aromatic ring in the molecule. .

Among the fluoran derivatives according to the present invention, preferred ones are represented by the following general formula (I). (In the general formula below,
The ring position of the fluorane ring is indicated by a number. j - In the above formula, R1 represents a group containing aryl carbonyl, R3 represents an amine residue, R2, R4 and R5 represent a hydrogen atom,
Represents a chlorine atom, an alkyl group, or a substituted alkyl group.

Especially preferred as R1 is an arylcarbonylalkyl group represented by 5-CHCOAr. However, R5 here represents H or alkyl, and Ar represents a substituted or unsubstituted aromatic ring. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, an acyl-nitro group, a carbamoyl group, and an alkoxycarbonyl group. The substitution position of COOR1 with respect to the anilino group at the no position is preferably the para position or the ortho position.

Among these fluorane derivatives, those having a -COOR1 group at the ortho-position of the anilino group are particularly preferable because they develop a black hue. On the other hand, those having a substituent at the meta- to no-e position of the anilino group have a greenish hue.

R3 is a primary or secondary amine residue having a total carbon number of less than it, such as dioctylamino, diethylamino, N-ethyl-N-P-tolylamino, N-methyl-N-cyclohexylamino, piperine, benzylamino, toluidino, p - selected from ethyltoluidino, cyclohexylamino, dibutylamino, diethylamino, etc.

In the fluorane derivative according to the present invention, 7θ6C ~ -200
Those having a melting point of 0C are preferred, and an appropriate one can be selected depending on the phenol derivative used.

The heat-sensitive recording material containing the fluoran derivative according to the present invention has sufficient color density and color development sensitivity, and the developed dye is extremely stable compared to dyes produced from existing color formers, and can be exposed to light for long periods of time and heated. It is particularly advantageous in terms of long-term preservation of records, since it hardly changes color or fades even when humidified. Fluorane derivatives also have excellent stability, and do not undergo deterioration or coloring even after long-term storage, and have near-ideal performance as color formers.

Also, preferred examples of compounds among the phenol derivatives according to the present invention are compounds having at least one phenolic hydroxyl group, and more preferably compounds having one of the j-4 t positions are unsubstituted. Phenol & Ct bis(
hydroxyphenyl)alkane derivative, bis-(3
-Chloro-4! -H)'roxyphenyl)alkane derivative, bis-(4L-hydroxyphenyl)sulfone,
These include (couhydroxyphenyl)-(μ'-alkoxyphenyl) sulfone derivatives, P-hydroxybenzoic acid ester derivatives, salicylic acid and alkyl or aralkyl substituted products thereof, or zinc salts thereof.

The following compounds are typical examples of phenol derivatives.

+112. ．． 2-bis(μm hydroxyphenyl)propane + 2)/,/-bis(l-hydroxyphenyl)cyclohexane (3)/,/-bis(3-chloro-guhydroxyphenyl)cyclohexane (41/,/-bis(- 3-chloro-l-hydroxyphenyl)-2-ethylbutane (5) benzyl P-hydroxybenzoate (6) j, j-
Resin mixture of zinc di-α-methylbenzylsalicylate (7) p,<z'-dihydroxy-37-isopropyldiphenylsulfone The following compounds are representative examples of the fluoran derivatives according to the present invention.

(IIJ-(o-7 enacyloxycarbonyl)anilino-t-diethylaminofluorane 121 -2- o
-(p-promophenacyloxycarbonyl)anilino-6-diethylaminofluorane-lan(31,2-io-phenacyloxycarbonyl)anilino-t-diethylaminofluorane(412-o-(
1)-Methylphenacyloxycarbonyl)anilino-
μm Methyl-diethylaminofluorane (5) 2-(o-7 enacyloxycarbonyl)anilino-4-N-ethyl, isoamylaminofluorane (6) -2-(o-naphthoylmethyleneoxycarbonyl)anilino- t-Diethylaminofluorane (71-2-(o-7enacyloxycarbonyl)anilino-J-N-ethyl, cyclohexylaminofluorane (8)-2-(o-α-methylphenacyloxycarbonyl)anilino- 6-Diethylaminofluorane These compounds of the present invention are prepared by reacting the corresponding fluoran compound having a carboxyl group with α-halogeno-substituted 10-substituted acyl aromatics under extremely mild conditions of stirring at room temperature for about 1 j minutes. Synthesized with good yield.

For compounds such as fluorane that have groups that are easily affected by reactions under harsh conditions, such as substituted amino groups, ether bonds, and lactone rings, the ease of synthesis described above is a major advantage. .

Next, a general method for manufacturing the recording material according to the present invention will be described. When used as a heat-sensitive recording material, a dye precursor containing the entire fluoran derivative of the present invention, a phenolic substance, and, if necessary, a thermofusible substance are sufficiently added to a liquid in which a binder is dissolved or dispersed in a solvent or a dispersion medium. A coating liquid is created by finely pulverizing and mixing, and then adding inorganic pigments such as kaolin, talc, and calcium carbonate. To this, add paraffin wax emulsion, latex binder, sensitivity improver, metal soap, antioxidant, hindered phenol, charge control agent such as mirabilite, salt, sorbitol, antifoaming agent, ultraviolet absorber, etc. can do.

The coating solution is applied to a support such as paper, plastic sheet, or resin-coated paper and dried. When preparing a coating liquid, 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.

The amounts of each component constituting the heat-sensitive recording material are: 7 to 2 parts by weight of the dye precursor containing the fluoran derivative according to the present invention, 1 to 1 part by weight of the phenol derivative, 0 to 30 parts by weight of the thermofusible substance, and the pigment. 1.17 parts by weight of the binder and 20 to 300 parts by weight of the dispersion medium.

As the dye precursor, one or more of the fluoran derivatives of the present invention may be used in combination, or compounds known as color formers for pressure-sensitive papers such as crystal violet lactone and fluoran 94 may be used with the fluoran derivatives of the present invention. They may be used in combination. Water is most desirable as the dispersion medium.

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

In particular, water-soluble binders such as gum arabic, polyvinyl alcohol, hydroxymethyl cellulose, and carboxymethyl cellulose are desirable in relation to the dispersion medium.

As the thermofusible substance, stearic acid anilide, benzoin, α-naphthol benzoate, β-naphthol p-methylbenzoate, Nogutsu t-butylphenol phenoxy acetate, para-phenylphenol p-chlorophenoxy acetate, 4! Il'-
Cyclohexylitine diphenol diacetate, μ, μ
'-Isoprohyritene diphenol, β-phenylethyl-p-phenylphenol ether, stearic acid,
Erucic acid, nomilmitic acid, ξ-hydroxybenzoic acid methyl ester, phthalic acid diphenyl ester, triphenyl phosphate, hala-hydro-73-xydiphenyl ether, +21+2-bis(≠-(β)
-hydroxyethoxy)ferol)propane, para-bis(β-hydroxyethoxy)benzene, hydroquinone diacetate, and the like can be used. Among these, those having an aromatic ring are particularly preferred.

These substances are colorless solids at room temperature and exhibit sharp melting points at temperatures suitable for copying heating temperatures, that is, around 70,1200C.

Examples will be shown below, but the present invention is not limited only to these examples.

Synthesis Example 1 p-anisidine and 0-chlorobenzoic acid were condensed in the presence of a copper catalyst to obtain 11-carboxy μ'-methoxydiphenylamine. 0.0/j mole of this was condensed with 0.0/7 mole of cooxy-goodiethylaminobenzoylbenzoic acid using concentrated sulfuric acid/jm as a catalyst to obtain 2-o-carboxyanilino-ot-diethylaminofluorane. .

Then, in dimethylformamide, using potassium fluoride as a catalyst, the mixture was stirred with -/4L-phenacyl bromide at room temperature for is minutes to obtain phenacyl ester. It is a white crystal with a melting point of 137-r'c. (Compound of Example (1)) Synthesis Example 2 The same procedure was performed except that Kooxy-μm dibutylaminobenzoylbenzoic acid was used in place of Kooxy-Hiro-diethylaminobenzoylbenzoic acid in Synthesis Example 1.
Compound of example (3)) was obtained.

Example 1 Fluorane jt of Synthesis Example 1 and j% polyvinyl alcohol aqueous solution jOml were treated with a horizontal sand mill to reduce the particle size/
, 4Lμ of a dispersion liquid was obtained. On the other hand, BPA109, p-phenylphenol benzyl ether 702, kaolin 2
0? and j% polyvinyl alcohol aqueous solution 100ml
was treated in the same manner to obtain a dispersion having a particle size of i and sμ. Mix these dispersions thoroughly and create a paraffin wax emulsion jO dispersion! After adding a dispersion of v1 stearic acid anisidide If, it was coated on 1097 m2 of base paper so that the solid coating amount was 197 m2, and dried.

Coated paper is heated by facsimile with energy of 3jmJ/
Color was developed by heating with crn2. When the color density of the colored portion was measured using a Macbeth Co., Ltd. RD-type, the color density was 1.0 g.

Furthermore, the obtained color image had excellent stability, and in particular was very stable against light, and even when the image was irradiated with an ultraviolet lamp for one hour, there was almost no change in hue or density.

Example 2 Half of the fluoran derivative of Example 1 was replaced with J-anilino-3
A recording paper was obtained in the same manner except that -chloro-t-dibutylaminofluorane was used.

When color was developed at 33 mJ/cm 2 , color was developed quickly and with high density, and a thermal paper with extremely excellent stability of the developed color image was obtained.

Also, when the above-mentioned recording paper was sprayed with butyl acetate, it was colored vividly.

Example 3 Fluorane 31 of Synthesis Example 2 and Fluoranco f of compound (7)! Tivoli vinyl alcohol (jOml) was processed with a horizontal sand mill to obtain a dispersion with particle diameters i and sμ.

On the other hand, ll/-bis(≠-hydroxyphenyl)cyclohexane 79, BPA3y, β-naphthol benzyl ether 109. mW, kaolin 11? , zinc oxide rt,
and 100tnl of 5% polyvinyl alcohol were treated in the same manner to obtain a dispersion with a particle size of 44μ. After mixing these dispersions and adding a dispersion of zinc stearate emulsion 31 and stearic acid p-anisidide t1, the solid content was j, 697 m on a base paper of μjf/m2.
It was applied so that

When the color was developed in the same manner as in Example 1, a clear black image was obtained.

Patent applicant: Fuji Photo Film Co., Ltd. 77-

Claims (1)

[Claims] A recording material characterized by containing a fluoran derivative and a phenol derivative represented by the following general formula. However, here R1 is a group containing arylcarbonyl, R2,
R4 and R5 are H1 halogen atoms or alkyl groups, and R3 is an amine residue.