JPS61279591A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material enhanced in color forming properties, by incorporating an electron-donative colorless dye, an electron- acceptive compound and a bisaryloxyalkane derivative. CONSTITUTION:An electron-donative colorless dye, an electron-acceptive compound and a bisaryloxyalkane derivative are incorporated. The derivative preferably has a melting point of 40-180 deg.C. The thermal recording material comprising the bisaryloxyalkane derivative has a sufficient developed color density and a sufficient color forming sensitivity, undergoes little lowering of the sensitivity with time and little fogging, and shows sufficient fastness of developed color images. In addition, the thermal recording material shows favorable matching to a thermal head, and is free of the problems of scum adhesion, scuff marks or the like.

Description

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

<Prior art> A thermosensitive recording material using an electron-donating colorless dye and an electron-accepting compound is a special project! -/Hiroshi 032, special public Akira≠j-
4/jO, etc. The minimum performance that such a heat-sensitive recording material should have is (11) sufficient color density and color development sensitivity, (2) no fogging (color development phenomenon during storage during 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.

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

As a method, the melting point ftO of the electron-accepting compound itself is
The temperature may be increased from 700°C to 700°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, making them impractical.

Other methods include the combined use of an organic alcohol and a phenolic compound as an electron-accepting substance in Tokko Akihiroter/77≠r and Tokko Shoj/-32j67, or the use of multiple compounds with alcoholic hydroxyl groups. The use of valent metal salts is described. Makutoku Kosho J/- Kotata 4A
! No. 1 describes the use of a copolymer of hydroxyethyl cellulose and maleic anhydride.

Tokko Akira again! The addition of waxes is described in Tata No. 27j and JP-A No. 31 Akihiro R-/Tako.

Furthermore, Tokukai Sho≠T3Hirot≠No.2, Tokukai Sho≠ri-／／
jjjJtA, JP-A No. 0-/≠23!3, JP-A-J-2-10471tt, JP-A No. J-j436, JP-A No. 3-/1034, JP-A-53 -Hirotyzi
thioacetanilide, phthalonitrile, acetamide, di-β-
7-thiru p-phenylenediamine, fatty acid amide, acetoacetanilide, diphenylamine, penzamide,
Nitrogen-containing organic compounds such as carbazole etc.
It is described that thermofusible substances such as 3-di-m-)lylbutane, Hiro, Hiro'-dimethylbiphenyl, or carboxylic acid esters such as dimethyl inophthalate, diphenyl phthalate, dimethyl terephthalate, etc. are added as sensitizers. has been done. Also, British Patent Publication No. 2,0
7≠,! ! ! No. 2 describes the addition of vintate phenols.

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

In order to solve this problem, the present inventors have investigated thermofusible substances with high color development sensitivity, such as naphthoic acid derivatives, diphenoxyalkane derivatives, and phenoxyalkylcarboxylic acid phenyl esters [1]. Compounds and heat-sensitive recording materials containing them have sublimation properties and fC
However, it has disadvantages such as insufficient storage stability, poor matching with the thermal head, and poor compound safety.

<Object of the Invention> Therefore, the object of the present invention is to provide a constant heat-sensitive recording material which has sufficient color density and color development sensitivity and satisfies other requirements. It is to provide.

<Structure of the Invention> The objects of the present invention are achieved by a heat-sensitive recording material characterized by containing an electron-donating colorless dye, an electron-accepting compound, and a bisaryloxyalkane derivative.

Among the bisaryloxyalkane derivatives according to the present invention,
Those represented by the following general formula (I) are preferred.

Ar -0-R-W-R' -〇-Ar (I)
In the formula, Ar is a substituted or unsubstituted phenyl group or
A thyl group is represented by the above general formula (I
) Among the bisaryloxyalkane derivatives represented by the following general formula (I[), those represented by the following general formula (I[) are particularly preferred.

In the above formula, X, Y, Z, X', Y' and z' may be the same or different and represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, an alkyloxycarbonyl group, an acyl group, an aryl group. group, hydroxy group, aralkyl group or aralkyloxycarbonyl group, R and R' may be the same or different and represent a divalent group having 1 to 6 carbon atoms, W is 10CO-1-CQ-1 -CO-
1Y, X', and Y' may be linked to form a naphthalene ring.

Among the above bisaryloxyalkane derivatives, ≠0°
Those having a melting point of c, iro'c are preferable, especially j
Those having a melting point of O''C to /jo0C are preferred.

The thermosensitive recording material containing the bisaryloxyalkane derivative according to the present invention has sufficient color density and color sensitivity;
Moreover, there is little deterioration in color development sensitivity over time and fog, and the fastness of the color image after color development is also sufficient. Furthermore, it matches well with the thermal head, and there are no problems such as adhesion of debris or scratches.

Next, specific examples of the bisaryloxyalkane derivatives according to the present invention will be shown, but the present invention is not limited thereto.

l) Bis(phenoxyethyl) carbonate 2) Bis(
p-methylphenoxyethyl) carbonate 3) Bis(p-chlorophenoxyethyl) carbonate dip Bis(p-methoxyphenoxyethyl) carbonate His(p-ethylphenoxyethyl) carbonate 4) Bis(p-chlorophenoxyethyl) carbonate 7 ) Bis(α-naphthyloxyethyl) carbonate r) His(β-7thyloxyethyl) carbonate? ) Bis(3-7dinoxypropyl) carbonate IO) Bis(3-p-methylphenoxypropyl)
carbonate//) bis(4t-phenoxybutyl)carbonate/co)his(/-methyl-λ-phenoxyethyl)carbonate 13) his(phenoxyethyl)sulfone i4c>
'e varnish (p-1 tylphenoxyethyl) sulfo/ /! ) Bis(p-chlorophenoxyethyl)sulfone #) His(P-methoxyphenoxyethyl)sulfone/7) Bis(xylyloxyethyl)sulfonelr) Bis(phenoxyethyl)oxalate/ri) Bis(p
-Methylphenoxyethyl) oxalate 20) Bis(m-methylphenoxyethyl) oxalate 21) Bis(0-chlorophenoxyethyl) oxalate 22) Bis(3-phenogycyprovir) oxalate-3) Bis(0-methylphenoxyethyl) ) Ogiza V-
24') Bis(4/--phenoxybutyl)oxalate-2) β-≠'-methylphenoxyacetyloxyethoxytoluene 6) β-naphthoxyacetyloxyethoxytoluene λ7) β-phenoxyacetyloxyethoxytoluene Examples of electron-donating colorless dyes 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)-6-dimethylaminophthalide (i.e., crystal violet lactone);
3.3-bis(p-dimethylaminophenyl)7thalide, j-(p-dimethylaminophenyl)-J-(/, J
-dimethylindol-3-yl)7thalide, 3-(p
-dimethylaminophenyl)-3-(λ-methylindol-3-yl)7talide, etc., and diphenylmethane compounds include ≠, Hiro'-bis-dimethylaminohydrinbenzyl ether, N-halophenyl −
Examples of xanthine compounds include leucoauramine, N-2,''+j-IJ dichloroenyl leucoauramine, rhodamine-B-anilinolactam, rhodamine(p-nitroanilino)lactam, rhodamine/B(
p-chloroanilino)lactam, kojibe/dylamino-6-ethylaminofluorane, λ-anilino-6-
Dinitylaminofluorane, λ-anilino 3-methyl-6-dinitylaminofluoran, co-7nilino 3-
Methyl-4-cyclohexylmethylaminofluorane,
U-O-chloroanilino-6-dinithylaminofluorane, λ-m-chloroanilino-3-diethylaminofluorane, λ-(J,4-dichloroanilino)-6-diethylaminofluorane, noanilino-3-methyl- A
-N-ethyl-N-tetrahydrofur-7lylinofluorane, λ-anilino-3-methyl-j-N-butyl-
N-tetrahydrofurfurylaminofluorane, λ-anilino-3-methyl-a-N-ethyl-N-isobutylaminofluorane, λ-octylamino-6-dinithylaminofluorane, λ-rehexylamino-6-diethylamino Fluoran λ-m-trifluoromethylanilino-6-diethylaminofluoran, coptylamino-3-chloro-t-diethylaminofluoran, niethoxyethylamino-3-chloro-6-diethylaminofluoran, 2-p -chloroanilino-3-methyl-1
-dibutylaminofluorane, two-anilino-3-meth'
f-ru-6-sioctylaminofluorane, noanilino-3-chloro-4-diethylaminofluorane, coke phenylamino-6-diethylaminofluorane, λ
-anilino-3-methyl-t-diphenylaminofluorane, λ-phenyl-2-diethylaminofluorane,
No-anilino-3-methyl-j-N-ethyl-N-ynamylaminofluorane, λ-anilino-3-methyl-yo-chlorot-diethylaminofluorane, ni-anilino-3-methyl-bu-diethylamino-7-methylfluorane , Nianilino 3=methoxy-6-cyptylaminofluorane, --0-chloroanilino-6-dibutylaminofluoran, λ-p-chloroanilino 3-
Ethoxy-a-N-ethyl-N-isoamylaminofluorane, 2-0-chloroanilino+-p-butylanilinofluorane, 2-anilino-3-interdecyl-t
-diethylaminofluorane, -anilino-3-ethyl-6-dibutylaminofluorane, -anilino-3
-ethyl-4-N-ethyl-N-isoamylaminofluorane, noanilino-3-methyl-A-N-ethyl-
Examples of thiazine compounds include N-r-methoxypropylaminofluoran, aniline-3-chloro-a-N-ethyl-N-isoamylamine fluoran, benzoylleucomethylene blue, p-nitrobenzylleucomethylene blue, etc. IE6! ? , spiro-based compounds include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-cyclospirodinaphthopyran, 3-benzylspiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxy-benzo)
Examples include spiropyran and 3-propyl-spiro-dibenzopyran. These may be used alone or in combination.

Examples of electron-accepting compounds include phenolic compounds,
These include organic acids or their metal salts, oxybenzoic acid esters, etc. Phenol compounds are particularly preferred because they require only a small amount.
/4cOJY issue, Tokko Sho J/-Kota rJo issue, etc. Specifically, Hiro-tertiary butylphenol, Hiro-phenylphenol, Hiro-hydroxydiphenoxide, α-naphthol, β-naphthol, methyl-μm hydroxybenzoate, 2,2′-dihydroxybiphenyl, λ, 2-bis( ≠-Hydroxyphenyl)propane (bisphenol), Hiro, ≠'-inpropylidene bis(coptylaminol), /, l
-bis-(3-chloro-≠-hydroxyphenyl)cyclohexane, /,/-bis-(3-chloro-≠-hydroxyphenyl)-2-ethylbutane, ≠ 4c/-secondary-isobutylidenediphenol, ≠-hydroxy Benzoic acid benzyl ester, l-hydroxybenzoic acid-
m-10 lobenzyl ester, ≠-hydroxybenzoic e
β-7 enethyl ester, ≠-hydroxy-27,
t4 /-dimethyldiphenylsulfone, bis(β-μ
mhydroxyphenylthioethoxy)methane, /l 3
-bis-(Hiro-hydroxyphenylthio)-2-hydroxyprono3no, /-(Hiro-hydroxyphenyl)-/
-(J-β-pro(nyl-guhydroxyphenyl)cyclohexane, /-t-7'thyl-≠-p-hydroxyphenylsulfonyloxybenzene, ≠-N-pendylsul7-ammoylphenol, λ, 4A-dihydroxyan p-methylbenzyl ester, iA-dihydroxybenzoic acid-β-phenoxyethyl ester, λ
, Hiro-dihydroxy-4-methylbenzoic acid benzyl ester, and the like.

The bisaryl oxydia alkali/derivative used in the present invention is used after being dispersed in a dispersion medium to a particle size of 10 μm or less using a ball mill or the like. Alternatively, the electron-donating colorless dye and /IN may be added at the same time when the electron-accepting compound is dispersed in a dispersion medium using a ball mill or the like.

The electron-donating colorless dye and electron-accepting compound used in the present invention are pulverized and dispersed in a dispersion medium to a particle size of IOμ or less, preferably 3μ or less. As the dispersion medium, a water-soluble polymer aqueous solution having a concentration of 1 to 100 ml is generally used, and the dispersion is carried out using a ball mill, a sudo mill, an attritor, a colloid mill, or the like.

The ratio of the electron-donating colorless dye and the electron-accepting compound used is preferably between /'' and 10 to /:l by weight;
Furthermore, the range between /:j' and Koni J is particularly preferable. Further, the bisaryloxyalkane derivative is added at a weight ratio of 20% to 300% with respect to the electron-accepting compound, and particularly preferably ao4 to 10oes.

The amount of this bisaryloxyalkane derivative added is 0.
If LIJ is less than that, the sensitivity improvement effect aimed at by the present invention will not be sufficient, and if it is added in an amount of 300% or more, the heat capacity of the system will increase too much, resulting in a decrease in sensitivity.

The heat-sensitive coating liquid thus obtained is further added with additives that meet various requirements.

Examples of additives include oil-absorbing substances such as inorganic pigments dispersed in the binder to prevent staining of the recording head during recording, and fatty acids to improve mold releasability from the head. , metal soap, etc. are added. Therefore, in general, in addition to a color forming agent and a color developer that directly contribute to color development, a pigment wax, additives, etc. are coated on a support to form a heat-sensitive recording material.

Specifically, kaolin as a pigment, calcination force 1) 7
, Merck, waxite, diatomaceous earth, Jiff! 11/”'
Waxes selected from rum, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, titanium oxide, ζlium carbonate, urea-formalin filler, cellulose filler, etc. In addition to '7x, polyethylene wax, and higher fatty acid esters, etc.

Examples of the metal soap include polyvalent metal salts of higher fatty acids, such as zinc 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, droxyethyl cellulose, hydroxypropyl cellulose, ethylene-maleic anhydride copolymer, styrene/maleic anhydride copolymer, and imbutylene-maleic anhydride. Examples include acid copolymers, polyacrylic acid, polyacrylic acid amide, starch derivatives, casein, and gelatin. l? , a water-resistant agent (gelling agent, cross-linking agent) 1- for the purpose of imparting water resistance to these binders.
It is also possible to add an emulsion of a hydrophobic polymer, specifically, a styrene-butadiene rubber latex, an acrylic resin emulsion, etc.

The coating fluid is most commonly applied onto base paper, preferably neutral paper.

In general, the coating amount is 2 to 97 m2 as a solid content, the lower limit is determined by the density at the time of heat color development, and the upper limit is determined mainly by economic constraints.

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

Example (1) Preparation of sample/~t λ-anilino-3-chloro- which is an electron-donating colorless dye
6-dietheraminofluorancho, 3? and λ-anilino 3-methyl-A-N-methyl-N-cyclohexylaminofluorane λ, rt! Tipolyvinyl alcohol (Ken measurement P%, degree of polymerization 1ooo) aqueous solution O? They were dispersed in a ball mill for a day and a night. On the other hand, similarly, bisphenol A101, which is an electron-accepting compound, is dispersed overnight in a ball mill together with 100 ml of an aqueous polyvinyl alcohol solution. Furthermore, 10ff of the bisaryloxyalkane derivatives shown in Table 1! These +
After mixing the L type dispersion, kaolin (Jossia kaolin) CO2 was added to disperse well, and paraffin wax emulsion jO (4 dispersion (Chukyo Yushi Cellosol #≠Corest) was added to prepare a coating liquid.

The coating liquid was applied onto neutral paper having a basis weight of jtO1/m2 so that the solid content coating amount was 697 m2, and too
After drying at c for 1 minute, the coated paper was obtained by suit-calendering at a linear pressure of 60 KgW/cyn.

Coated paper requires 3 heating energy by facsimile! mJ
/ 11111'' to determine color density.

The results are shown in Table 1.

(2) Creation of comparative sample Using exactly the same recipe as that used to create sample l-♂,
A similar test was conducted using stearamide instead of the bisaryloxyalkane derivative.

The results are also shown in Table 1.

It can be seen from Table 7 that the recording material according to the invention clearly has a high sensitivity.

Procedural amendment (indication of February 1985 φ day 16 case Showa to year patent application No. 12 Co. 091)
No. 2, Title of the invention Thermal recording material 3. Relationship with the person making the amendment Patent applicant Address 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (520) Fuji Photo Film Co., Ltd. 4゜Date of amendment order Showa Mei ρ Date of the month r (shipment date) 5. Subject of amendment 6. We will submit an engraving of the amended statement (no changes to the contents).

Claims (1)

[Claims] A heat-sensitive recording material comprising an electron-donating colorless dye, an electron-accepting compound, and a bisaryloxyalkane derivative.