JPS62109682A - Recording material - Google Patents

Abstract

PURPOSE:To enhance the sensitivity to color development and improve the stability with time, by a method wherein a recording material consists of; a substrate and a recording layer formed thereon and containing an electron donating colorless dye, an electron accepting compound, and a compound shown by a specific formula. CONSTITUTION:An electron donating colorless dye, an electron accepting compound, and a compound shown by a formula (Ar1 and Ar2 designate aromatic rings, R designates a bivalent group having 8 or less carbon atoms, and X designates CO2) are dispersed in a binder to prepare a coating fluid. The coating fluid is dried after being applied on a substrate such as a neutral paper, whereby a recording material is formed. Concretely, as the compound shown by aforesaid formula, phenylthio acetate-p-biphenyl ester etc. is used. As the electron donating colorless dye, triarylmethane series compound etc. is used, and as the electron accepting compound, phenol compound etc. is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a recording material, and particularly to a heat-sensitive recording material with improved stability over time and color development.

<Prior Art> A thermosensitive recording material using an electron-donating colorless dye and an electron-accepting compound is disclosed in British Patent Co/uO≠≠2.

The properties that a heat-sensitive recording material should have are (1) sufficient color density, (2) no color development during storage of the spinning material used, and (3) sufficient fastness of the color material after color development. There are many things such as being , but at present we cannot obtain a haze that fully satisfies these.

Especially in recent years, with the speeding up of thermal recording systems, the above (1)
Research is being conducted intensively.

Methods for this include lowering the melting point of the electron-accepting compound itself to below 10'C, using an organic acid and a phenolic compound together as the electron-accepting substance, or using a polyhydric compound containing an alcoholic hydroxyl group. Using a metal salt, using a copolymer of hydroxyethylcellulose and maleic anhydride, adding waxes, thioacetanilide, phtaminitrile, acetamide, di-β-naphthyl-p-phenylenediamine, fatty acid amide, Nitrogen-containing organic compounds such as acetoacetanilide, diphenylamine, penzamide, carbazole, etc. or thermofusible substances such as co,3-di-m-)dylbutane, dimethylbiphenyl, or dimethylisophthalate, diphenyl. Attempts have been made to add carboxylic acid esters such as phthalate and dimethyl terephthalate as sensitizers, and to add hindered phenols.

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

<Object of the Invention> Accordingly, an object of the present invention is to provide a heat-sensitive recording material having sufficient color density and color development sensitivity and excellent stability over time. .

<Structure of the Invention> The object of the present invention is achieved by developing a heat-sensitive recording material characterized by using an electron-donating colorless dye field, an electron-accepting compound, and a metal compound represented by the following general formula (1). It was done.

Ar 8-R-X-Ar2 (I) Here, Ar Ar 2 represents an aromatic ring, R represents a divalent group having the following number of carbon atoms, and X represents CO□.

More specifically, Ar1, Ar 2ti, substituted or unsubstituted! Represents an aromatic ring consisting of a member or a condensed ring. It may contain oxygen atoms, nitrogen atoms, sulfur atoms, etc. in addition to carbon atoms.

From the viewpoint of raw material availability and handling, benzene rings and naphthalene rings are most advantageous.

When having a substituent, a cyano group, thioalkoxy group, acyl group, alkyl group, aralkyl group, alkoxy group, acylamino group, halogen atom, alkyloxycarbonyl group, aralkyl group or aralkyloxycarbonyl group, alkenyl group, cyclo Examples include one or more of alkenyl groups, oxy groups, thioalkoxy groups, alkanesulfonyl groups, carbonato groups, sulfo groups, sulfonato groups, and aryl groups.

Among these, groups having 7j or less carbon atoms, preferably 7j or less carbon atoms, have excellent performance.

For example, methyl group, ethyl group, inpropyl group, methoxy group, ethoxy group, allyl group, chlorine atom, fluorine atom,
Acetyl group, propionyl group, butoxy group, oxy group,
Examples include a thiomethoxy group, a methoxycarinyl group, a chloromethyl group, and a methoxyl group. R has a carbon atom number r or less, and particularly preferably linear or branched alkylene, oxaalkylene, thiaalkylene, or alkenylene. Among them, straight-chain alkylene, xaalkylene, polyoxaalkylene, thiaalkylene, etc. having the following number of carbon atoms are excellent in terms of ease of synthesis and ease of product purification.

In particular, it has affinity, high whiteness, and Ao"C-/lo'c
It is preferable to have a melting point of tz, oIIc~
/2! , O"C. The heat-sensitive recording material containing all the compounds of the present invention has sufficient color density and color sensitivity i, and has little deterioration in color sensitivity over time and fog, and has a good color image after color development. The robustness is also sufficient.

Here, a synthesis example of the compound represented by the general formula (I) will be shown.

j - <Synthesis Example> Phenylthioacetic acid-p-biphenylphenylthioacetic acid/l, If is reacted with sulfonyl chloride/utttl in toluene at room temperature for 1 hour.

Excess sulfonyl chloride is distilled off under reduced pressure on a water bath of about 1 to 30 ml. This is easily reacted with p-phenylphenol in the presence of a base such as triphenylamine, and the reaction solution is poured into water. Crystals are obtained.

mprter 201' Next, specific examples will be shown, but the present invention is not limited thereto.

/) 7-ethylthioacetic acid-2-biphenylene ester 2) Phenylthioacetic acid-p-ethoxybenzene ester 3) Phenylthioacetic acid-,2-naphthalene ester IA) Phenylthioacetic acid-p-chlorobenzene ester A- j) p-)! j ruthioacetic acid p-biphenyl ester t) p-tolylthiobutyric acid p-chlorobenzene ester 7) m-) IJ ruthioacetic acid p-biphenyl ester r) p-chlorobenzene thiovaleric acid phenyl ester t) phenylthioacetic acid p-fucro Hexylbenzene ester 10)/-benzoyloxicuconiphenylthioethane and the like.

Examples of the electron-donating colorless dye used in the present invention include triarylmethane compounds, diphenylmethane compounds,
Xanthine compounds, thiazine compounds, spiropyran compounds, etc. are used. To illustrate some of these, triarylmethane compounds include 3,3-bis(p-dimethylaminophenyl)-thu-dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, J -(p-dimethylaminophenyl)-
J-(/,j-dimethylindol-3-yl)phthalide, J-(1)-dimethylaminophenyl)-3-C2
-methylindol-3-yl)phthalide, etc.
Diphenylmethane compounds include φ, Hiro'-bis-
Dimethylaminobenzhydrin benzyl ether, N-
Halophenyl-leukoolamine, N-2,4Z, j-
) dichlorophenylleucoolamine, etc., and xanthine compounds include rhodamine-B-anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine B (p-chloroanilino)lactam, cokebenzylamino-t-diethylaminofluoran, co-anilino 2-diethylaminofluorane, -1-anilino-3-methyl--diethylaminofluorane, co-anilino 3-methyl-4-cyclohexylmethylaminofluorane, J-0-chloroanilino-6-dimethylaminophenyl 7,. 2-m-chloroanilino-t-diethylaminofluorane, J-(J,4!-dichloroanilino)-G-diethylaminofluorane, -1octylamino-6-dinithylaminofluorane, λ-dihexylaminofluorane -diethylaminolluorane, J-m-)
Lifluoromethylanilino-t-diethylaminofluorane, coptylamino-3-chloro-t-diethylaminofluorane, 2-ethoxyethylamino-3-chloro-t-diethylaminofluorane, λ-p-chloroanilino-3- Methyl-t-dibutylaminofluorane, co-anilino-3-methyl-t-dioctylaminofluorane, 2-anilino-3-chloro-4-diethylaminofluorane, λ-rephenylamino-6-ethylaminofluorane λ-anili /-J-Methyl-6-siphenylaminofluorane, λ-phenyl-diethylaminofluorane, co-anilino-3-methyl-t-ethyl-N-yneamylaminofluorane, λ-7=
IJ/-j-methyl-7-10rot-diethylaminofluorane, co-anilino 3-metyl-4-diethylamino-7-methylfluoran, co-anilino 3-methoxy-1-dibutylaminofluoran/, λ-O-lyroloanilino -dibutylaminofluorane, λ-p-chloroanilino-3-ethoxy-J
-N-isoamylaminofluorane, -10-chloroanilino-bu-p-butylanilinofluorane, co-anilino 3-pentadecyl-t-diethylaminofluorane, -1-anilino 3-ethyl-4-dibutylaminofluorane, λ- Anilino 3-ethyl-4-N-ethyl-j-N-ethyl-N-ynamylaminofluorane,
co-anilino-3-methyl-t-N-ethyl-N-r-
Methoxypropylaminofluorane, -anilino 3
Dithiazine-based compounds include benzoylleucomethylene blue, p-nitrobe, and dithiazine blue, and spiro-based compounds include 3-
Methyl-spiro-dinaphthopyran, 3-ethyl 5/I/-
Examples include spirodinaphthopyran, J,J'-dichlorospirodinaphthopyran, 3-benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)spiropyran, 3-propyl-spiro-dibenzopyran, etc. . These can be used alone or in combination, and in particular,
It is preferable that two foods exhibiting a black color are used together.

Examples of electron-accepting compounds include phenolic compounds,
Organic acids or their metal salts, oxybenzoic acid esters,
There are inorganic acids, etc., and phenol compounds are particularly preferable because they can be used in small amounts.

For example, Id2-(4'-hydroxyphenyl)-,2-
(3-isopropylguhydroquiphenyl)propane, 2-(4A-hydroxyphenyl)2-(j-71
J Rou≠-Hydroxyphenyl)propane, λ-(<2
-hydroxyphenyl)-2-(3-methyl-μm hydroxyphenyl) 20pan, α-inpropyl-β-naphthol, methyl-≠-hydroxybenzoate, monomethylated dihydroxybiphenyl 1.21 + 2-bis(μm hydroxyphenyl)propane (bis7er/-el A), ri'-isopropylidene bis(comethylphenol), /,/-bis-(3-chloro-7-hydroxyphenyl)cyclohexane, /,/-bis-(3 −
Chloro-μm hydroxyphenyl)-2-ethylbutane, ≠, μ′-isobutylidene diphenol, μm hydroxybenzoic acid benzyl ester, ≠-hydroxybenzoic acid-m-chlorobenzyl ester, g-hydroxybenzoic mβ-phenethyl ester, Hiro- Hydroxy-2/
, p/-dimethyldiphenylsulfone, 1-t-butyl-μ-p-hydroxyphenylsulfonyloxybenzene, ≠-N-benzylsulfamoylphenol,
Co,≠-dihydroxybenzoic acid-p-methylbenzyl ester, 2.4t-dihydroxybenzoic acid-β-phenoxyethyl ester 1.2.4t-dihydroxy-t-
Methyl benzoic acid benzyl ester, zinc chloride or rotane zinc salt may be mentioned.

The ether compound used in the present invention is used after being dispersed in a dispersion medium to a particle size of jμ or less using a crusher or an isobaric disperser. Alternatively, the electron-donating colorless dye and/or electron-accepting compound may be added and dispersed simultaneously when the electron-donating colorless dye and/or electron-accepting compound are dispersed in a dispersion medium using a ball mill, sand mill, or the like.

Particularly, if the colorless dye is dispersed at the same time as the colorless dye, there is an advantage that the obtained dispersion is less colored.

Furthermore, there is an advantage that the sensitivity tends to increase if the electron-accepting compound is dispersed at the same time.

The electron-donating colorless dye and the electron-accepting compound used in the present invention are pulverized and dispersed in a dispersion medium to a particle size of 3 microns or less, preferably co-microns or less. As the dispersion medium, a water-soluble aqueous solution of Hatake molecules having a concentration of approximately 0.2 to JJ is generally used, and dispersion is carried out using a ball mill, sand mill, attritor, colloid mill, or the like.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between /:10 and /:/, and particularly preferably between /:j and 3, by weight. 't The specific adduct of the present invention is 20% of the electron-accepting compound.
It is added at a weight ratio of 3θOtS or less, particularly preferably 4tos/jO% or less.

If the amount added is less than 20%, the sensitivity improvement effect aimed at by the present invention will not be sufficient, and addition of JOO'4 or more will result in a decrease in sensitivity.

Additives are added to the coating liquid thus obtained in order to meet various requirements.

゛ Examples of additives include dispersing oil-absorbing substances such as inorganic pigments to prevent the recording head from becoming dirty during recording, and fatty acids and metals to improve the releasability of the head. Soap etc. are added. Therefore, in general, in addition to color formers and color developers that directly contribute to color development, pigments, waxes, antistatic agents, surfactants, additives, etc. are coated on a support to form a heat-sensitive recording material. become.

Specifically, pigments include kaolin, calcined kaolin, talc, waxite, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium carbonate,
titanium oxide, barium carbonate, barium sulfate, calcined gypsum,
Urea-formalin filler/4t- selected from urea-formalin filler, gypsum, cellulose filler, etc. Examples of waxes include paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax, and higher fatty acid esters.

Examples of metal soaps include fatty acid metal salts, such as lead stearate, aluminum stearate, calcium stearate, and zinc oleate.

These are dispersed and applied in a binder.

Water-soluble binders are generally used, such as polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, ethylene-maleic anhydride copolymer aluminum salt, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer. Polyacrylic acid, polyacrylic acid, acrylamide copolymer, modified polyacrylic acid amide, starch derivative, casein, gelatin, etc. In addition, water-resistant agents (gelling agents, cross-linking agents) are added to these binders for the purpose of imparting water resistance.
Emulsions of hydrophobic polymers, specifically styrene-butadiene rubber latex, acrylic resin emulsions, etc. can also be used.

Furthermore, a protective layer made of polyvinyl alcohol, methylol acrylamide copolymer, etc., methylol melamine, boric acid, etc. can be added.

The coating solution is most commonly coated and calendered onto a smooth jμ to 2jOμ support, preferably neutral paper.

Common application methods include air knife coating, blade coating, and curtain coating.

In general, the coating amount is 2 to 1097 m2 in terms of solid content, with the lower limit determined by the density during color development by heating, and the upper limit determined mainly by economic constraints.

<Examples of the Invention> Examples are shown below, but the present invention is not limited to these examples only.

Example (1) Preparation of sample Electron-donating colorless dye λ-anilino-3-chloro-4-diethylaminofluorane λ,Of and 2-anilino-3-methyl-A-N-methyl-N-isoamylaminofluorane J, jf and ether derivatives io shown in Table 1
t and tS polyvinyl alcohol (Ken Keidoku Tatachi, Polymerization F11000) aqueous solution 3jf was dispersed in a sand mill. On the other hand, similarly, bispheno-)vA and tof, which are electron-accepting compounds, are dispersed in a sand mill together with 100 ml of a 1% polyvinyl alcohol aqueous solution.

After mixing these dispersions, kaolin (Jossia kaolin) 209 was added and dispersed well, and then paraffin wax emulsion jO% dispersion (Middle East oil and fat Cellosol@4A2r)3. ! A coating liquid was prepared by adding f.

The coating liquid was applied onto neutral paper having a basis weight of 1097 m2 so that the solid content coating amount was t, r t/m, and to'c'1? After drying for 1 minutes, a recording material was obtained by applying a linear pressure of 4w/dry suit to a calender.

The recording material is heated by facsimile.
/mm 2 was heated to develop color, and the color density was determined.

The results are shown in Table 1.

(2) Preparation of Comparative Sample A similar test was conducted using the exact same formulation as that used to prepare the sample, but using stearic acid amide instead of the ether derivative of the present invention.

The results are also shown in Table 1.

It can be seen from Table 1 that the recording material according to the invention clearly has a high sensitivity.

-／　l- -lter 60～ノ(021F.

2. Title of the invention Recording material 3. Relationship with the person making the amendment Patent applicant Location 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Contact address 11 Fuji Photo Film Co., Ltd. 2G-30, 21-N Nishi-Azabu, Minato-ku, Tokyo 106 Tokyo Honban Telephone: (406) 2537 Table: Date of amendment order Voluntary action 5, Subject of amendment: Specification 6, Contents of amendment We will submit a clean copy of the specification (no changes to the content).

Claims (1)

[Scope of Claims] A recording material Ar_1S-R-XAr_2 characterized by using an electron-donating colorless dye, an electron-accepting compound, and a compound represented by the following general formula, provided that Ar_1 and Ar_2 are aromatic rings. , R represents a divalent group having 8 or less carbon atoms, and X represents CO_2.