JPS62211188A - Recording material - Google Patents

Abstract

PURPOSE:To provide a thermal recording material imparting sufficient developed color density and having sufficient color forming sensitivity and stability with the elapse of time, by using an electron donative leuco dye, an electron acceptive compound and a compound represented by a specific formula. CONSTITUTION:An electron donating leuco dye, an electron acceptive compound and a compound represented by formula (I) (wherein R1, R2 and R3 are a group selected from a hydrogen atom, an alkyl group, an acyl group, an alkoxy group, an aryl group, a thioalkyl group, a hydroxy group, a halogen atom, an alkoxycarbonyl group, a cyano group and an alkenyl group, R3 is a 2 or more C alkyl group and X is a 1-10 C divalent group. Further pref., a group wherein the number of carbon atoms of the substituent of each of R1-R4 is 15 or less, pref., 4 or less is excellent from the aspect of capacity) are used. A thermal recording material imparts sufficient developed color density and has sufficient color forming sensitivity and is reduced in the lowering with the elapse of time in the color forming sensitivity and fog, and forms a color image having sufficient fastness after color development.

Description

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

<Prior Art> A heat-sensitive recording material using both an electron-donating colorless dye and an electron-accepting compound is disclosed in British Patent No. λl No. 04L4L.

The properties that a heat-sensitive recording material should have are (1) sufficient color density, (2) no color development during storage before use, and (3) sufficient fastness of the color body after color development. However, there is currently nothing 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.

Methods include adding waxes, thioacetanilide, phthalonitrile, acetamide, di-β
-naphthyl-p-phenyl diamine, fatty acid amide,
Nitrogen-containing organic compounds such as acetoacetanilide, diphenylamine, penzamide, carbazole, etc.
．． Addition of thermofusible substances such as 3-di-m-tributane, 4L, lA'-dimethylbiphenyl, or carboxylic acid esters such as dimethyl phthalate, diphenyl phthalate, dimethyl terephthalate, etc. as sensitizers, hindered Attempts have been made to add 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 which has sufficient color density and color development sensitivity and is excellent in 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, an electron-accepting compound, and a compound represented by the following general formula (I). Ta.

However, R1, R2, and R4 are hydrogen atoms, alkyl groups, acyl groups, alkoxy groups, aryl groups, thioalkoxy groups, hydroxy groups, halogen atoms, alkoxycarbonyl groups, cyano groups, and alkenyl groups. , R3 represents an alkyl group having 2 or more carbon atoms. or,
X represents a divalent group having a carbon number of IO to IO. More preferably, a group in which the number of carbon atoms of the R1 to R4 substituents is /j or less, preferably μ or less has excellent performance.

For example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, methoxy group, ethoxy group, propioxy group, impropioxy group, thioaloxy group, thioethoxy group, thiopropioxy group, chlorine atom, bromine atom,
Indicates a fluorine atom, acetyl group, allyl group, chloromethyl group, methoxycarbonyl group, hydroxy group, etc. A thioalkoxy group represents an alkylthio group.

X is a covalent group having 10 or less carbon atoms such as alkylene, oxaalkylene, alkenylene, arylene or alkynylene, especially alkylene, oxaalkylene, alkynylene or toeha-CnH2n-1-CmH2m having t or less.
OCmH2m+CH2←-CH=CH-(CH2+-1
+CH2Fuku-c=c÷CH2Yu+C2H4O-1-C2
There are H4-, etc. n and m are integers of 10 or less, particularly l to b.

Furthermore, it is lipophilic, has high whiteness, and has a range of to0c~/ro0c.
It is preferable to have a melting point of
Those having a melting point of i2r, o'c are preferred. The heat-sensitive recording material containing the compound gold of the present invention has sufficient color density and color sensitivity, and also exhibits little deterioration in color sensitivity over time and fog, and has sufficient fastness of colored images after color development.

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

Synthesis example> β-
(≠-methylphenoxy)ethyl tosylate 30. lt
, Carbonated / J″, 2f, Goutioethoxyphenol / j, ≠r Weigh the sample. Dimethylformamide 0v
Add tlf and keep stirring on a hot water bath until β-(tA-methylphenoxy)ethyl tosylate disappears. The reaction mixture is poured into ice-water J00rrtl, and the precipitated reaction product is recrystallized from ethyl acetate/methanol. mp
Tatar 10o.

Specific examples will be shown next, but the present invention is not limited thereto.

/l/-(44-thioethoxyphenoxy)-2-phenoxyethane Jl/-(Hiro-thioethoxyphenoxy)-≠-phenoxybutane J)/-(≠-thionormalpropioxyphenoxy)
-2-phenoxyethane 4L)/-(≠-thioethoxyphenoxy)-2-<Hiro-methylphenoxy)ethane j)/-(44-thioethoxyphenoxy)-2-(μ
mmethoxyphenoxy)ethane4)/-(4L-thioethoxyphenoxy)-λ-(μ
m-ethoxyphenoxy)ethane7)/-(4t-thioethoxyphenoxy)-2-(≠
-chlorophenoxy)ethaner)/-(≠-thiomethoxyphenoxy)-λ-phenoxyethanedi1/-(≠-thioethoxyphenoxy)-2-(
2,≠-dimethylphenoxy)ethane 10)/, 2-bis(Hiro-thioethoxyphenoxy)ethane//)/, Hiro-bis(Hiro-thioethoxyphenoxy)butane/21/, 2-bis(≠- Thionormalpropioxyphenoxy)ethane/? )/-(It~thioethoxyphenoxy)-λ-
(e-ethylphenoxy)ethane and the like.

Examples of the electron-donating colorless dyes used in the present invention include triarylmethane compounds, diphenylmethane compounds,
Gysanthene compounds, thiazine compounds, spiropyran compounds, etc. are used. Some examples of these include triarylmethane compounds such as 3.3-bis(p-dimethylaminophenyl 1-A-dimethylaminophthalide), 3.3-bis(p-dimethylaminophenyl)phthalide, j-(p-dimethylaminophenyl)-
3-(/,3-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-
methylindol-3-yl) phthalide, etc., and diphenylmethane compounds include μ,μ'-bis-dimethylaminobenzhydrinbe/zyl ether, N-halophenyl-leukoolamine, N-2,≠, j- Trichlorophenylleucoolamine, etc., and xanthine compounds include rhodamine-B-anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine B (p-chloroanilino)lactam, and λ-rebenzylamino-6-diethylaminofluor. Oran 2-anilino-2-diethylaminofluorane, λ-anilino 3
-Methyl-6-dinithylaminofluorane, λ-anilino-3-methyl-6-cyclohexylmethylaminofluorane, λ-0-chloroanilino-6-ethylaminofluorane, λ-m-chloroanilino- Di-diethylaminofluorane-(3,≠-dichloroanilino)
-+-diethylaminofluorane, no-octylamino-t-diethylaminofluorane, 2-diphenylamino-bu-diethylaminofluorane, 2-m-trifluoromethylanilino-6-diethylaminofluorane, 2
-butylamino-3-chloro-6-diethylaminofluorane, λ-ethoxyethylamino-3-chloro-4-
Diethylaminofluorane, 2-p-chloroanilino-
3-methyl-t-dibutylaminofluorane, 2-anilino-3-methyl-6-sioctylaminofluorane,
2-anilino-3-chloro-6-diethylaminofluorane, 2-diphenylamino-6-diethylaminofluorane.

λ-anilino-3-methyl-2-diphenylaminofluorane, 2-phenyl-6-diethylaminofluorane, λ-anilino-3-methyl-6-N-ethyl-N-ynamylaminofluorane, no-anilino-3-methyl-j- Chloro-6-diethylaminofluorane, no-anilino-3-methyl-6-dinithylamino-fu-methylfluoran, λ-anilino-3-methoxy-6-cyptylaminofluoran, X-0-chloroanilino-ot-dibutylamino Fluoran, 2-p-chloroanilino-3
-ethoxy-x-H-isoamylaminofluorane, J
-o-Chloroanilino-A-p-butylanilinofluorane, co-anilino-3o-tadecy-t-diethylaminofluorane, u-7-nilino-3-ethyl-6-dibutylaminofluorane, co-anilino-3-ethyl-6
-N-ethyl-6-N-ethyl-N-isoamylaminofluorane, λ-anilino-3-methyl-6-N-ethyl-N-r-methoxypropylaminofluorane, λ-
Anilino 3-chloro+-N-ethyl-N-isoamylaminofluorane, etc.Adithiazine compounds include benzoylleucomethylene blue, p-nitrobenzylleucomethylene blue, etc.; spiro compounds include 3-methyl-spiro -dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-cyclospirodinaphthopyran, 3-penzylspirodinaphthopyran, 3-methyl-naphtho-(3-methoxy-benzo)spiropyran, j-po Examples include pill-spiro-dibenzopyran. When these are used alone or in combination, it is preferable that two types exhibiting a black color are used in combination.

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.

Example, tbax-(a-hydroxyphenyl)-2-(3-
isopropylhydroxyphenyl)pronogun, 2
-(≠-Hydroxyphenyl)-2(J-71J-Hiro-Hydroxyphenyl)pronotone, 2-(Hiro-Hydroxyphenyl)-J-(J-Methyl-≠-Hydroxyphenyl)propane, α-isopropyl- β-naphthol, methyl-≠-hydroxybenzoate, monomethylated dihydroxybiphenyl, λ, 2-bis(≠-hydroxyphenyl)furopane (bisphenol A), Hiro, Hiro'-isopropylidene bis(low methylphenol),
/,/-bis-(3-chloro-≠-hydroxyphenyl)cyclohexane, /,/-bis-(3-chloro-≠-
hydroxyphenyl)-2-ethylbutane, ≠ pl-
imbutylidene diphenol, ≠-hydroxybenzoic acid benzyl ester, hiro-hydroxybenzoic acid-m-chlorobenzyl ester, μm hydroxybenzoic eβ-7 enethyl ester, ≠-hydroxy-2/I≠'-dimethyldiphenylsulfone, 1- -p-hydroxyphenylsulfonyloxybenzene, μ-N- to t-butyl-4
Benzylsulfamoylphenol, co≠-dihydroxybenzoic acid-p-methylbenzyl ester, J, 44
-dihydroxybenzoic acid-β-phenoxyethyl ester,! , ≠-dihydroxy-t-methylbenzoic acid benzyl ester, l,7-di(Hiro-hydroxyphenylthio)-3,J-dioxahebutane, zinc chloride, zinc rhodan, and the like.

The diether compound used in the present invention is used after being dispersed in a dispersion medium to a particle size of 3 μm or less using a crusher or a dispersing machine. Alternatively, the electron-donating colorless dye and/or electron-accepting compound may be added and dispersed at the same time when the electron-donating colorless dye and/or electron-accepting compound is dispersed in the 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 sensitivity can be easily increased if the electron-accepting compound is dispersed at the same time.

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 3μ or less, preferably λμ or less. As a dispersion medium, a water-soluble polymer aqueous solution having a concentration of about 0.0 to 14 is generally used, and dispersion can be carried out using a ball mill, sand mill, attritor, etc.
This is done using a colloid mill or the like.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1:10 and 1:/ by weight, more preferably 1. Particularly preferred is between r and λ:3. Further, the specific compound of the present invention is added to the electron-accepting compound in a weight ratio of 20% or more and JOOqb or less, particularly preferably 4 to 4 or more and 1 to θ or less.

If the amount added is less than 2014, the effect of improving sensitivity that is the objective of the present invention will not be sufficient, and if it is added in an amount of 300% or more, the sensitivity will decrease.

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

Examples of additives include dispersing K, inorganic pigments, and other oil-absorbing substances to prevent the recording head from becoming dirty during recording, and fatty acids and metal stones to improve the releasability of the head. Ken etc. are added. Therefore, in general, in addition to color formers and color developers that directly contribute to color development, K, pigments,
Wax, antistatic agents, surfactants, additives, etc. are coated onto the support to form a heat-sensitive recording material.

Specifically, the pigments include kaolin, calcined kaolin, talc, waxite, cypress powder, calcium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium carbonate,
Titanium oxide, barium carbonate, (iii! oxide, barium carbonate,
Selected from calcined gypsum, 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 metalstones include fatty acid metal salts, 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, hydroxyethyl cellulose, hydroxypropyl cellulose, ethylene-maleic anhydride copolymer aluminum salt, styrene-maleic anhydride copolymer, and inbutylene-maleic anhydride copolymer. Examples include polymers, polyacrylic acid, acrylamide copolymers, modified polyacrylic acid amides, starch derivatives, casein, gelatin, and the like. In addition, for the purpose of imparting water resistance to these binders, water resistant agents (gelling agents, crosslinking agents) are added, and emulsions of hydrophobic polymers, specifically styrene-butadiene rubber latex, acrylic resin emulsions, etc. You can also use

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

The coating liquid is most commonly smooth jμ or λ! It is coated on a θμ support, preferably neutral paper, and calendered.

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

Generally, the coating amount is 2~/Of,/m in terms of solid content.
2, the lower limit is determined by the density during color development by heating, and the upper limit is determined mainly by economic constraints.

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

Example (1) Preparation of sample 2-anilino-3-chloro- which is an electron-donating colorless dye
6-diethylaminofluora/λ, O1 and co-anilino 3-methyl-4-N-methyl-N-isoamylaminofluorane 3. J'S' and the diether compounds shown in Table 1 were dispersed in a sand mill together with an aqueous solution of polyvinyl alcohol (1000% polyvinyl alcohol).

On the other hand, bisphenol A, which is also an electron-accepting compound,
l0f'Jj (!4 Polyvinyl alcohol aqueous solution / 0
0? It is also dispersed in a sand mill.

After mixing these dispersions, 20 tf of kaolin (Georgia kaoli yl) was added for good dispersion, and 3.J:ff of Saranino G rough-in-wax emulsion 10% dispersion (Middle East fat cellosol #μ21r) was added to prepare a coating liquid.

The coating liquid was applied onto neutral paper having a basis weight of 10 f/m2 so that the solid content coating amount was j, 6197 m2, and t
After drying at OOC for 1 minute, a super calender was applied at + linear pressure and rK9W/crn to obtain a recording material.

The recording material is heated by facsimile.
Color was developed by heating at mJ/wx2 to determine the color density (gold).

The results are shown in Table 7.

(2) Preparation of Comparative Sample A similar test was conducted using exactly the same formulation as that used for preparing the sample, using stearic acid amide instead of the diether compound 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.

Date of Hirotsuki, Showa t/2019, March 7, 1939 Patent application (A) 2, Title of the invention Recording material 3, Relationship with the case of the person making the amendment Patent applicant 4, Subject of the amendment ``In the description'' ``Scope of Claims'', Column 5 of ``Detailed Description of the Invention'', Contents of Amendment (1) The entire statement of the scope of claims shall be amended as shown in the ``Attachment.''

(2) Structural formula in the third line from the bottom of the specification 3 [ and correct it.

(3) Details! ≠Page 1st line "Thioalkoxy group"? "Alkylthio group" and correct it.

"Claims" A recording material characterized by using an electron-donating colorless dye, an electron-accepting compound, and a compound represented by the following general formula, provided that R1, R2, and R4 are hydrogen atoms, alkyl group, acyl group, alkoxy group, aryl group, alkylthio group, hydroxy group, halogen atom, alkoxycarbonyl group, cyano group, alkenyl group, and R3 represents an alkyl group having 2 or more carbon atoms. Further, X represents a divalent group having from 1 to 10 carbon atoms.

Claims (1)

[Claims] A recording material characterized by using an electron-donating colorless dye, an electron-accepting compound, and a compound represented by the following general formula ▲ Contains mathematical formulas, chemical formulas, tables, etc. ▼ However, here R_1 , R_2, R_4 represent a hydrogen atom, an alkyl group, an acyl group, an alkoxy group, an aryl group, an alkylthio group, a hydroxy group, a halogen atom, an alkoxycarbonyl group, a cyano group, an alkenyl group, and R_3
represents an alkyl group having 2 or more carbon atoms. Moreover, X represents a divalent group having 10 carbon atoms.