JPH02172790A - Heat sensitive recording material - Google Patents

Abstract

PURPOSE:To enhance coloring sensitivity, the stability of a coloring image by providing a heat sensitive coloring layer containing electron donative achromatic dye and a color developing substance and specific triester compound on a support to form a heat sensitive recording material. CONSTITUTION:Electron donative achromatic dye, a color developing substance, and triether compound represented by a formula I (where X, Y, Z are phenyl group, naphthyl group which may independently have substituted group, R is hydrogen atom, 1-6C alkyl group) are dispersed in aqueous water-soluble polymer binder solution such as polyvinyl alcohol, etc., to prepare a heat sensitive coloring layer forming coating solution. A support such as a sheet or plastic film is coated with the coating solution, and dried to form a heat sensitive coloring layer, thereby obtaining a heat sensitive recording material. The trietser compound of the formula I is used as a sensitizer to improve coloring sensitivity and the stability of coloring image.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a recording material using a triether compound, particularly a heat-sensitive recording material having excellent color development and stability.

(Prior art and its problems) In general, heat-sensitive recording materials can be recorded in a short time with a relatively simple device without complicated processing such as development and printing, do not generate noise, and are relatively inexpensive. It has the following advantages and is widely used in computer output, printers such as calculators, recorder facsimiles for medical measurement, automatic ticket vending machines, label fields, copying machines, etc.

The basic principle of these recording methods is that an electron-donating colorless dye and an electron-accepting compound called a color developer chemically contact each other, thereby changing the dye into a colored body.

The chemical contact is effected by heating with a thermal head, thermal pen, laser beam, or the like.

In recent years, with the advancement of information-related technology, especially facsimile I
In fields such as J, there is an increasing demand for faster recording and smaller devices, and the heat-sensitive recording materials used in these fields are also required to have even higher sensitivity.

One method for increasing sensitivity is to lower the melting point of the color developer to a level that maintains storage stability.

However, it is difficult to control and optimize the melting point of phenolic compounds, which are color developers, through molecular design, and this method is impractical due to cost constraints.

Another method is to add a melting point depressant (sensitizer) to the color developer, and many compounds such as amides and waxes have been proposed (for example, in JP-A-53-3913
No. 9, JP-A-53-26139, JP-A-53
-5636, JP-A-53-11036, Paper and Pulp Technology Times Vol. 28, No. 9, p. 29 (1985), etc.).

Desirable characteristics of these sensitizers are: (1) They should have a melting point in an appropriate range, do not develop color when combined with a color developer/dye, and at the same time should melt at a sufficiently low temperature.

(2) Good compatibility with color developer/dye.

(3) The color development of the compounding system is 7 years.

(4) The color image is stable and there is little fading over time (5)
It is easy and inexpensive to use industrially.

However, there is still no known material that fully satisfies all of these requirements.

(Objective of the Invention) An object of the present invention is to solve the above-mentioned problems and provide a heat-sensitive recording material that has high coloring sensitivity, high coloring density, and high background whiteness.

(Means for Solving the Problems) The present inventors have found that the above problems can be achieved by using a specific triether compound in combination with an electron-donating colorless dye and a color developer. The present invention has been achieved by finding that a highly sensitive heat-sensitive recording material can be provided which has a high ability to effectively dissolve them during heating and effectively maintain its fluidity even during the subsequent cooling process.

That is, the present invention is based on the formula: % Formula % 1 In the formula, X, Y and 2 independently represent a phenyl group or a naphthyl group which may have a substituent, and R is a hydrogen atom or a carbon atom having 1 ~6 alkyl group. ] Provided is a heat-sensitive recording material characterized by containing a triether compound represented by the following.

In the above formula, X, Y and Z represent a phenyl group or a naphthyl group which may have a substituent, and examples of the substituent include a halogen atom, an alkyl group having 1 to 7 carbon atoms, a cycloalkyl group, and an acyl group. , an alkoxy group, an aryl group, an aryloxy group, a nitro group, or a cyan group.

Examples of compounds included in the present invention are shown below, but the invention is not limited thereto.

I′+(I113)2 Ihu113 The triether compound of the present invention can be easily obtained in high yield by etherifying a trimethylol alkane compound by a general etherification reaction, It has a melting point of up to 100%, and can be used as a heat-sensitive recording material in combination with an electron-donating colorless dye and an electron-accepting compound as a sensitizer.

As the colorless or light-colored electron-donating dye used in the heat-sensitive recording material of the present invention, leuco dyes such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, and indolinophthalide-based dyes are preferred;
They may be used alone or in combination of two or more.

Specifically, 3,3-bis(p-dimethylaminophenyl)-phthalide, 3,3-bis(p-dimethylami/phenyl)-6-dimethylaminophthalide, 3゜3-bis(
p-dimethylaminophenyl)-6-dimethylaminophenyl, 3,3-bis(p-dimethylaminophenyl)
-6-chlorophthalide, 3.3bis(p-dibutylamino/phenyl)-phthalide, 3-cyclohexylamino-
6-chlorofluorane, 3-dimethylamine/-5,1-
Dimethylfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino/-7-methylfluoran, 3-diethylamino/-7,8-benzfluoran,
3-diethylamino-6-methyl-7-chlorofluorane, 3-(N-p=nitrile N-ethylamiy) -
6-methyl-7-anilinofluorane, 3-virolidi/
-6-methyl-7-anilinofluorane, ? (N-(3
“-trifluoromethylphenyl)amino)-6-7′
Ethylaminofluoran, 3-7 ethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamine-7-(o-chloroanilino)fluoran, 3-dibutylamino/-7-(o-chloroanilino)fluoran, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6methyl-7-anilinofluorane, 3-diethylamino-6-methyl- 7-
Anilinofluoran,: 3-(N,N-diethylamino)-5-methyl-7(N,N-dibenzylami/)fluoran, benzoylleucomethylene blue, 6'-chloro-8methoxyhenzoindo Ituno-virillospiran, 6"-bromo-3"-methoxy-benzoindolino-
Pyrylosvirane, 3-(2''-hydroxy-4dimethylaminephenyl)-3-(2'-methoxy-5''-chlorophenyl)phthalide, 3-(2'-hydroxy/-4''-dimethylaminephenyl)- 3 (2°-methoxy-5
"-nitrophenyl)phthalide, 3-(2'-hydroxy-4-diethylaminophenyl)-3-(2'-methoxy/-5'-methylphenyl)phthalide, 3-(2'-
Methoxy-4゛dimethylaminophenyl)-3-(2゛
-hydroxy-4'-chloroo-5°-methylphenyl)
Phthalide, 3-morpholino-7-(N~propyl-p4
trifluoromethylanilino)fluorane, 3-pyrrolithia7-p-trifluoromethylanilinofluorane,
3-diethylamino-5-chloro7-(N-benzyl-
p-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-pchlorophenyl)methylaminofluorane, 3-diethylamine-5-chloro-7-(α
-phenylethylamine) fluoran, 3-(N-ethyl 1)-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(.

methoxycarbonylphenylamino)fluorane, 3-
Diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-ethylamino-7-piveridinofluorane, 2-chloro1' 3-(N-methyltoluidino)-7-(p-n butylanilino)fluoran , 3-(N-henfrew N-cyclohequinylamino)
-5,6-henzo7-α-naphthylamino-4°-bromofluorane, 3-diethylamino-6-methyl-7-
me/tidino-4°, 5°-benzofluorane, 3,6-
Dimethquine fluorane, 3-(p-dimethylaminephenyl)-3-phenyl phthalide, 3-di(l-ethyl-2
-methylindole)-3-yl-phthalide, 3-7ethylamino-6-phenyl-7azafluorane, 3.3
-bis(p-diethylaminophenyl)-6-dimethylaminophthalide, 3-(p-dimethylaminophenyl)
-3-(p-dibenzylaminophenyl)phthalide, 3
Examples include, but are not limited to, -(N-ethyl-Nn-amyl)amino-6-methyl-7-anilite fluorane.

On the other hand, as the electron-accepting compound ('H4 colorant) used in the heat-sensitive recording material of the present invention, for example, phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids and metal salts thereof, etc. are preferable; Or a mixture of two or more types can be used. A specific example is shown below.

4.4°-isopropylidene bisphenol (bisphenol A), 4,4′-isopropylidene bis(0-methylphenol), 4.4′-5ec-butylidene bisphenol, 4,4°-isopropylidene bis( 2-t
ert-butylphenol), 4,4°-isofluorylidene bis(2-chlorophenol), 2゜2゛-methylenebis(4-methyl-6-tert-butylphenol), 2,2°-methylenebis(4-ethyl- 6-Ler
t-butylphenol), 4,4'-butylidene bis(
6tert-butyl-2-methylphenol), 4,4
-Thiobis(5-jert-butyl 2-methylphenol), 44'-diphenolsulfone, 4,4'-diphenolsulfoxide, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, benzyl protocatechuate, gallic acid Acid stearinobe 1.7-bis(4-hydroxyphenylthio)-3,5-dioxahebutane, 1.5-bis(4-hydroxyphenylthio)-3oxabencune, 1.3-bis(4-hydroxyphenylthio) )-propane, 1,3-bis(4-hydroxyphenylthio)-2-hydroquinepropane, N,N
'-diphenylthiourea, salicylanilide, 5-chlorosalicylanilide, salicyl-0-lyroloanilide,
2-hydroxy-3-naphthoic acid, 2-hydroxy-1
Examples include, but are not limited to, -naphthoic acid, (2) hydroquine-2-naphthoic acid, and the like.

The dye and developer described above and the triether compound of the present invention are micronized to a particle size of 17 microns in a dispersion medium to prepare a coating solution. The ratio of the dye and developer used is generally in the range of 1:10 to 10:1 by weight,
More preferably, it is in the range of 1.5 to 2:1.

The triether compound of the present invention can be used as a sensitizer in an amount of 0.1 to 15 parts by weight per 1 part by weight of the color developer.

As the dispersion medium, an aqueous solution of a water-soluble polymer compound having a concentration of about 10% is generally used.

Specifically, polyvinyl alcohol, starch and its derivatives, methylcellulose, hydroxyethylcellulose, cellulose derivatives such as dinorphoki/methylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic Aqueous solutions of synthetic polymers such as acid ester/methaxolic acid copolymers, sodium alginate, casein, gelatin, etc. are used, and dispersion is carried out using a hole mill, sand mill, attritor, etc.

The above-mentioned water-soluble polymer compound also functions as a binder to support and bond the paint components onto the base material after coating, but in order to impart water resistance to the paint film, a water-resistant agent is also added to the coating liquid. Alternatively, a polymer latex such as styrene-butadiene latex or acrylic emulsion can be added.

Furthermore, in the heat-sensitive recording material of the present invention, the coating liquid includes:
7. Various additives are added depending on the change.

For example, inorganic pigments such as kaolin, talc, aluminum carbonate, aluminum hydroxide, magnesium/lamb hydroxide, magnesium carbonate, titanium oxide, and fine particulate IJh are used to prevent stains on the recording head. Fatty acids, metal soaps, specifically stearic acid, behenic acid, aluminum stearate, zinc stearate, calcium stearate, zinc oleate, and the like are added as properties improvers.

The coating liquid containing these components is applied onto the surface of a base material such as paper or plastic film using a plate, air knife, roll coater, gravure, etc., and then dried and smoothed to form a coating. A heat-sensitive recording material of the invention is obtained.

<Examples> The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto.

Note that all parts and percentages shown in the examples are based on weight.

Synthesis Example 1 [1,1,1 Tri(phenoxymethyl)propane (Compound No. 1)] 13.42 g (0.10 mol) of trimethylol butylene and 62.91 g (0.10 mol) of 4-toluenesulfonyl chloride.
33 moles) was added to 7 sets,
Under water cooling, add 75 ml of 48% sodium hydroxide solution to 40
'C or lower (for 30 minutes). After the dropwise addition was completed, the temperature was raised to 50 to 60'C and a reaction was carried out for 30 minutes.

Subsequently, phenol 31.03 (0,
33 mol) in acetonitrile (10 ml) at 60°
After the mixture was added dropwise at C.C., the mixture was refluxed for 3 hours.

After the reaction was completed, the reaction mixture was immersed in water, extracted three times with methylene chloride, and the organic layer was washed successively with 10% hydrochloric acid and water. It was then dried over anhydrous sodium sulfate, and the solvent was distilled off to obtain 36.07 g (yield: 99.5%) of a crude product of 1,1.1-)'J (phenoxymethyl)propane. Thin layer chromatography (TLC) of this crude product and '
It was found from the H-NMR spectrum that it was almost pure. For analysis, a sample roughly recrystallized from a mixed solvent of n-hexane/toluene was used.

Melting point 102-103°C Elemental analysis (wt%) CH Actual value 79,25 7.19 Calculated value
79.53 7.231-[-NMR (deuterated chloroform solvent) δ (ppm: TN, IS standard) 0.62 (3H, t, J 7.6H2) 1.34
(21(,q, J=7.6Hz)3.77 (6
H,,s) 7.3-7.75 (151(,m) Synthesis Example 2 [1,illsu(phenoquinemethyl)ethane (compound N
o, 2) 1.1.1- in the same manner as in Synthesis Example 1 except for using trimethylolethane instead of trimethylolpropane.
Tri(phenoxy/methyl)ethane was obtained (yield 987%)
).

Ridge point 105-106℃ Elemental analysis (weight %) Actual measured value calculated value - NMR MS basis) 0.88 (3) (,s) 3.77 (61 (,s) 7.3-7.75 (15H Loss amount ↓ 79, 28 (deuterated chloroform solvent) m) 6.8G 6.94 δ (ppm: T [Liquid A] 3-N-methyl-N-cyclohexylamino-6-methyl 7-anilinoflu Oran 10% polyvinyl alcohol aqueous solution overnight [Liquid B] Bisphenol Δ Calcium carbonate 10% polyvinyl alcohol aqueous solution [Liquid C] 1,1,1-tri(phenoxymethyl)propane 10% polyvinyl alcohol aqueous solution 10 parts 20 parts 10 parts 10 parts 10 parts 10 parts 10 parts A solution, B solution and C solution were each separately atomized using a Santo mill until the average particle size was 3μ or less, and then 1 part of ΔN, [3
One coating liquid was prepared by mixing 2 parts of i<'i and 2 parts of liquid C. This coating solution was coated on a commercially available high-quality paper with a tsubo of 150 W/m 2 (coating ■: solid content 69/m 2 ), and after drying, smoothing treatment was performed using a supercalenter to obtain a heat-sensitive recording material.

Example 2 - A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the following [Liquid D] was used instead of [Cl 戊] in Example 1.

[Liquid D]1. l, 1-tri(phenoxy 10 parts methyl)ethane 10% polyvinyl alcohol 10 parts Aqueous solution Example 3 Thermal recording was carried out in the same manner as in Example 1 except that the following [Eiffl] was used instead of [Liquid 1B] of Example 1. I got the material.

[Liquid E] 10 parts of p-hydroxybenzoic acid 10 parts of benzyl calcium carbonate 10 parts of 10% polyvinyl alcohol A heat-sensitive recording material was obtained.

Female Comparative Example 1 A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the following [Liquid F] was used instead of [Liquid C] in Example 1.

[FM] Stearic acid amide 10 parts lO%
Polyvinyl alcohol 10 parts Aqueous solution ratio 1 bite Example 2 A thermosensitive recording material was obtained in the same manner as in Example 1, except that the following [Liquid G] was used in place of [C1ff1] in Example 1.

[Gi night] p-benzylbiphenyl 10 parts 10
% polyvinyl alcohol 10 parts aqueous solution A heat-sensitive recording material was obtained in the same manner as in Example 3, except that water was used instead of [Liquid C] in Example 3.

The heat-sensitive recording materials obtained on each side above were evaluated for color development sensitivity and color image stability in the following manner. The results are shown in Table 1.

<Evaluation method> ■Color development sensitivity Using a dynamic color development test device manufactured by Taishoku Denki Co., Ltd., color was developed at a printing energy of 0.45 mJ/dot. )
It was measured with

■ Colored image stability ■ The colored sample prepared in
After using the device for one month in H), the color intensity was measured again.
The retention rate of that concentration was calculated.

Comparative Example 3 As is clear from the first surface color development sensitivity and color image stability results table, the heat-sensitive recording material of the present invention has a
．． Despite the low printing efficiency of 45 mJ/dat, it exhibited very excellent color development sensitivity, and the stability of the color development was also significantly superior to that of the comparative example.

[Effects of the Invention] By using the triether compound of the present invention as a sensitizer, excellent color development sensitivity and stability of color images, which are desirable as a heat-sensitive recording material, were exhibited.

Therefore, the present invention can be applied to various fields as a heat-sensitive recording material.

Claims (1)

[Claims] 1. Formula: ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, X, Y and Z independently represent a phenyl group or a naphthyl group which may have a substituent, R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ] A heat-sensitive recording material characterized by containing a triether compound represented by the following.