JPH011578A - Chromogenic recording material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Use Separation] The present invention relates to a color-forming recording material with excellent light fastness of color-forming images.

[Conventional technology and its problems]

Currently, the mainstream color-forming recording materials are those using fluoran compound-based color-forming dyes. However, there is an extremely strong desire to improve its durability, especially its light resistance. For example, the purpose of improving light resistance is
Di-β-naphthyl-p- in No. 0-145'553 D
The use of 722 diamine has been proposed, but this method is still unsatisfactory for long-term sunlight irradiation.

[Means to solve the problem]

The present inventors conducted intensive research to solve this problem and found that the use of a phenothiazine compound is an extremely effective means for improving the above-mentioned light resistance.

[Structure of the invention]

That is, the present invention relates to a color-forming recording material which is composed of a fluoran compound-based color-forming dye and a color developer, and which contains a phenothiazine compound in the image portion to be formed.

Color-forming recording materials composed of a fluoran compound and a color developer are well known. Such color-forming recording materials include thermal recording paper 1. Information recording in the form of recording paper such as pressure-sensitive copying paper, heat-sensitive transfer recording, electric heat-sensitive recording, electrophotography using toner containing an acidic substance as a developer, ultrasonic recording, photosensitive recording, electron beam recording, etc. It is widely used in printing systems, as well as color-forming materials in the form of stamping materials, stamp inks, typewriter ribbons, etc., all of which require close contact between color-forming dyes and color developers in a variety of ways. held in a state of obstruction by physical means, heated,
This method breaks the rules in terms of the principle of bringing color-forming dyes and color developers into close contact with each other by removing obstacles that have impeded their contact by applying energy such as pressure or electromagnetic waves.

Such a color-forming recording material develops a vivid color tone upon contact with a color-forming dye and a color developer, or gradually fades when stored for a long period of time, particularly under exposure to light. However,
When a dye developed by the action of a color developer and a small amount of a phenothiazine compound coexist, the fading of the developed dye is significantly reduced and the durability of the color development is improved. Therefore, it is necessary that the phenothiazine compound be intimately mixed with the colored dye.

However, even if phenothiazine compounds come into contact with uncolored fluoran compounds or color developers, their effects may be adversely affected.
-I don't give it either. Therefore, in the present invention, the phenothiazine compound is mixed in advance with one or both of the color-forming dye and the color developer, or it is placed in a separate phase from the color-forming dye and the color developer. It is made to mix with the coloring agent at the stage when they are brought into contact with each other. Furthermore, in the case of heat-sensitive recording paper and pressure-sensitive copying paper, the phenothiazine compound can be applied in the form of post-treatment after color development.

The fluoran compound-based coloring dye used in the present invention is a fluoran compound represented by the formula. In this formula, R1 is a halogen atom, a lower alkoxy group, an aryl group,
[L] An alkyl group having 1 to 18 carbon atoms which may be directly substituted and which may have a side chain; substituted with a halogen atom, a lower alkyl group or a lower alkoxy group; or a cycloalkyl series, where R2 is water, or a cycloalkyl series; R2 may be directly substituted with water, a halogen atom, a lower alkoxy group, an aryl group, or a heterott<m:+ chain. Optional number of carbon atoms: 1 to 18
an alkyl group; an alkyl group optionally substituted with a halogen atom, a lower alkyl group, or a lower alkoxy group;
or a cycloalkyl group, R1 and R2 may form a ring together with the nitrogen atom to which they are bonded, R5, R4, and R6 are the same or different, hydrogen atom; halogen atom; lower alkyl group or lower alkoxy group, and R5 is a hydrogen atom; a halogen atom; an alkyl group having 1 to 18 carbon atoms which may have a side chain; or substituted with a halogen atom, a lower alkyl group, a lower alkoxy group, or a halomethyl group. R5 and R4 or R5 and R6 may be bonded together to form a naphthalene ring with group A, and these naphthalene rings are halogen atoms, lower alkyl groups, or lower alkoxy groups. It may be substituted, X is a halogen atom, and m is 0 or an integer from 1 to 4.

Some specific examples of such fluoran compounds are listed below, but the fluoran compounds used in the present invention are not limited to these.

6-Danithylamino-6-methyl-phenylaminofluoran 6-di-n-butylamino-6-methyl-7-phenylaminofluoran 3-N-methyl-N-n-propylamino-6-methyl-7-phenyl Aminofluorane 5-N-ethyl-N
-1-Butylamino-6-methyl-7-phenylaminofluorane 3-N-ethyl-N-1-pentylamino-
6-Methyl-7-phenylaminofluoran 3-N-ethyl-N-n-hexylamino-6-methyl-7-phenylaminofluoran 3-N-methyl-N-cyclohexylamino-6-methyl-7- Phenylaminofluoran 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-phenylaminofluoran 5-N-ethyl-N-p-ethylphenylamino-6-
Methyl-7-7 enylaminofluoran, 6-pyro 9 cy / -6-methyl-7-7 enylaminofluoran 5-pi is liren 6-methyl-phenylaminofluoran 6-diethylamino-6-chloro- 7-phenylaminofluoran 3-diethylamino-7-o-chlorophenylaminofluoran 5-diethylamino-7-m-)lifluoromethylphenylaminofluoran (the above are black-coloring fluoran compounds) 3-diethylamino-6-methyl -7-Chlorofluoran 3-diethylamino-6,7-cyclofluoran 6-diethylamino-7-chlorofluoran 6-diethylamine-5,6-benzofluoran 3-N-ethyl-N-1-butylamino -6-methyl-
7-Chlorofluoran 3-N-ethyl-N-i-butylamino-7-chlorofluoran 3-N-ethyl-N-i-butylamino-5,6-benzofluoran 3-cyclohexylamino-6- Chloro 7 Luolan (red color-forming fluoran compound) filtra-diethylamino-7-dibenzylaminofluoran 3-diethylamino-5-methyl-7-dibenzylaminofluoran 3-N-ethyl-N-i-butylamino -7-dibenzylaminofluoran 3-pyrrolidino-7-dibenzylaminofluoran 5-N-ethyl-N-earth-butylamino-7-phenylaminofluoran 6-pyrrolidino 7-phenylamino, nofluoran (green coloring) chemical fluorane compounds).

These fluoran compounds are used singly or in combination of two or more.

The above-mentioned fluoran compound-based color-forming dye develops color when it comes into contact with a color developer, as shown in Shukaku. Various compounds such as acidic substances, nitro- or cyanobenzoic acid metal salts, and organic halogen compounds that generate halogen radicals when heated are known as color developers. Acidic substances are most commonly used as color developers for fluoran compounds because they are easy and inexpensive.

Examples of such acidic substances include the following: Acid clay, activated clay, attapulgite, bentonite, colloidal silica, aluminum silicate, magnesium silicate, zinc silicate, tin silicate, calcined kaori/non-acidic substances such as talc, oxalic acid, maleic acid, ? Aliphatic carboxylic acids such as citric acid, succinic acid, stearic acid, benzoic acid, p-tert-butylbenzoic acid, 4-hydroxybenzoic acid, 7-thalic acid, phthalamic acid, 2,3,4.5 -Tetrachloro-N,N-dibutylphthalamic acid, salicylic acid, 6-isoprobylsalicylffi, 3-phenylsalicylic acid, 3-cyclohexylsalicylli, 3,5-di-tert-butylsalicylic acid, 6-methyl-5-benzyl salicylic acid, 3-phenyl-5-(2,2-dimethylbenzyl)salicylic acid,
3,5-di(2-methylbenzyl)salicylic acid, 2-
Aromatic carboxylic acids such as hydroxy-1-benzyl-3-naphthoate, these aromatic carboxylic acids and zinc, tin,
Salts with metals such as magnesium, calcium, aluminum, titanium, etc., phenolic resins such as p-phenylphenol-formal/m fat, p-butylphenol-acetylene resin, these phenolic resin color developers and the above aromatic carboxylic acids. mixtures with metal salts of bisphenol A, 4.4'-secanglyptylidene bisphenol, 4.4'-cyclohexylidene bisphenol, 2.2'l hydroxydiphenyl, pentamethylene-bis(4-hydroxybenzoate). ), L7-di(4-hydroxyphenylthio)-3,5-'; sulfur-containing bisphenol compounds such as oxaheptane, 4-hydroxybenzo! Hensyl, ethyl 4-hydroxybenzoate, 4-hydroxybenzopropyl, 4-hydroxybenzoisopropyl, 4-hydroxybenzoic butyl, isobutyl 4-hydroxybenzoate, chlorobenzyl 4-hydroxybenzoate, 4-hydroxybenzoate , is 4 dimethylbenzyl, 4
-Hydroxyamine, '4 go? & diphenylmethyl, 4-hydrochlorinated esters, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-
Hydroxy-41-phthoxydiphenylsulfonate, hydroxysulfonate, dimethyl 14-hydroxyphthalate, dicyclohexyl 4-hydroxyphthalate, 4-
4-hydroxyphthalic acid diesters such as diphenyl hydroxy7talate, e.g. 2-hydroxy-6-fJ
Esters of hydroxynaphthoic acid such as ruboxina 7-talene, or hydroxyacetophenone, p-phenylphenol, benzyl 4-hydroxyphenylacetate, p-benzylphenol, hydroquinone monobenzyl ether, and the like. These compounds may be used singly or in combination of two or more.

Examples of the phenothiazine compounds used in the present invention include, but are not limited to, those listed below.

Phenothiazine, N-methylphenothiazine, 1-methylphenothiazine, 2-methylphenothiazine, 6,7
-dimethylphenothiazine, 2-methoxyphenothiazine, 4-methoxyphenothiazine, 3,7-sheeter
t-Butylphenothiazine, 3.7-tert-octylphenothiazine, 2-chlorophenothiazine, 2
-cyanophenothiazine, 2-trifluoromethylphenothiazine, N-phenylphenothiazine, N-benzylphenothiazine, etc. These compounds can be used singly or in combination of two or more.

Thermal recording paper using the color-forming recording material of the present invention can be produced using conventional methods for manufacturing thermal recording paper (for example, Japanese Patent Publication No. 69-27579,
It can be manufactured according to the manufacturing method described in Japanese Patent Publication No. 43-4160, Japanese Patent Publication No. 45-14039, or Japanese Patent Application Laid-Open No. 59-7087.

Namely, fluoran compounds, color developers (usually phenol [OH
A suspension is prepared by dispersing each of the compound (containing a compound containing a group containing a compound having a group) and the phenothiazine compound in the form of fine particles in an aqueous solution of a water-soluble binder, along with a filler if necessary, and the mixture is mixed and applied to a paper surface and dried. . In this way, a heat-sensitive recording paper carrying a heat-sensitive coloring degree on the paper surface containing a fluoran compound, a color developer, and a phenothiazine compound is produced.

The above suspension may further contain dispersants, desensitizers, antiblocking agents,
Antifoaming agents, fluorescent whitening agents, etc. can be contained.

Pressure-sensitive copying paper can be manufactured using the color-forming recording material of the present invention by conventional methods such as US 1FJ-No. 2.548,
No. 365, No. 2.548,566, No. 2,800
, No. 457, specification No. 2,800,458, JP-A-58-112041 or JP-A-58-13973.
It can be manufactured according to the method described in Publication No. 8.

That is, a phenothiazine compound is dissolved together with a fluoran compound in an organic solvent, and then microcapsules containing the solution are prepared.

Pressure-sensitive copying paper is a unit (
In addition, a medium paper carrying a color developer on the upper surface and microcapsules on the lower surface may also be included in the unit), or a so-called self-content paper in which the microcapsules and the color developer are coated on the same paper surface. It may be paper.

Examples of the solvent include diphenylmethane, alkylnaphthalene, and alkyltriphenyl.
An inert, nonvolatile material that dissolves the fluoran compound well is used.

Example 1 Toluene 451C3-diethylamino-6-methyl-7
-phenylaminofluorane 2.0v and phenothiazine 1. Of was dissolved.

When a pressure sensitive copying paper coated with clay was immersed in this solution, taken out and air-dried, the clay-coated surface of the paper was colored black. When this surface was exposed to sunlight for 3 hours, its color changed to purple-black, becoming darker than before exposure.

The color densities of these coloring surfaces were measured using a Macbeth reflection-change needle (filter: Ratten≠106) and are listed in Table 1 together with the values obtained in Comparative Example 1.

Implementation of Table 1 (AI colored paper 1.00 1.0
6 Color paper of Comparative Example 1 0.91 0.8
4 Comparative Example 1 Toluene 45 yK3-diethylamino-6-methyl-
7-phenylaminofluora:y 2. O? only was dissolved.

The same pressure-sensitive copying paper used in Example 1 was soaked in this solution, and the color was developed in the same manner as in Example 1. The color was slightly lighter than that in Example 1. there were. When this colored surface was exposed to sunlight for 3 hours, the color tone faded to purplish brown. Color vividness IK measurement of these coloring surfaces (direction was written in 'LAy31'). From Example 1 and Comparative Example 1, when phenothiazine was colored with 6-diethylamino-6-methyl-phenylaminofluorane clay, the coloring density was measured. It was found that it has the effect of making the color darker and also has the effect of significantly increasing its fastness to sunlight.

Example 2 Dispersion A-1 (Fluorane compound dispersion) Minofluoran clay 11.5r15%
pvA aqueous solution 41.5 f water
40. O
r Dispersion B-1 (Developer Dispersion) Bisphenol A 10.5r Clay 8.0115% PV
A aqueous solution 41.5? water
40.07 Dispersion c
-1 (phenothiazine compound dispersion) phenothiazine
7. Or clay
11.5r15% PVA aqueous solution
41.5r water
40.0 polydispersion i C-2 2-methoxyphenothiazine is used in place of fetch azide y in dispersion C-1 Dispersion C-5 2-trifluoromethylphenothiazine is used in place of phenothiazine in separated liquid C-1 Dispersion C-4 Dispersion Q 2-chlorophenothiazine was used instead of phenothiazine in C-1.A mixture of the above composition was mixed with glass peas (diameter 1-1.
5m) Put it in a polyethylene bottle with 150r, stopper it tightly, attach it to a conditioner, and shake it for several hours.Dispersion A-1, Dispersion B-1, Dispersion tC-1, Dispersion C-
2. Dispersion C-3 and dispersion fi C-4 were prepared.

Dispersion i [dispersions C-1, C-2, C-3 and C-4 in a mixture of 1 part by weight of A-1 and 2 parts by weight of dispersion B-1
Add 1 M parts of each separately and mix well, and add 41 (
Coating liquids No. 3 were prepared, and they were applied to white paper and dried to produce four types of thermal recording paper.

These four types of thermal recording paper were heated to 150℃ using a dry heat tester.
Heat it to develop a color (black), then expose the colored area to sunlight for 2 days.
It was exposed for 0 hours. Macbeth reflection densitometer (filter: Thiazine + 106) was used to measure the density of the colored area before and after exposure.
The measured values are listed in Table 2.

Table 2 Phenothiazine 1.26 t28
10t, 6 gin not used (comparison fii2) 1.24 1.1
3 91.1 Comparative Example 2 Dispersion-D Clay 18.5?15%
PVA dispersion 41.5 y water
40.07 Dispersion-D having the above composition was prepared, and 1 inch part of it was mixed with 1 part by weight of dispersion A-1 in Example 2 and 2 g of dispersion B-1.
A coating solution containing no phenothiazine compound was prepared by mixing with ffi catfish, which was coated on white paper and dried to produce heat-sensitive recording paper. This thermosensitive recording paper was colored in the same manner as in Example 2, then exposed to sunlight, and the color density was measured. The results are shown in Table 2.

Example 3 Dispersion B-2 was prepared by using 4-hydroxy-4-isopropoxydiphenyl sulfone as a color developer in place of the bisphenol in Dispersion B-1 of Example 2,
Using dispersion B-2 instead of dispersion B-1 in Example 2, four types of heat-sensitive recording paper were manufactured in the same manner as in Example 2, and heat-colored and exposed to sunlight were performed in the same manner as in Example 2. The color density was measured. The results are shown in Table 3.

Table 3 Phenothiazine 1.29 - 1.30 1
00.8 Phenothiazine 2-chlorophenothiazine 1.27 1.3
1 103.1 Not used (comparison example 2) 1.
28 1.01 7B, 9 Comparative Example 3 One layer of dispersion A-1 in Example 2, two layers of dispersion B-2 in Example 6, and 1M company of dispersion in Comparative Example 2 A coating solution was prepared by mixing the two parts, and this was applied to white paper and dried to produce heat-sensitive recording paper. This was colored in the same manner as above, and then exposed to sunlight to measure the color density. The results are shown in Table 3.

Example 4 Dispersion B-3 was prepared by using benzyl 4-hydroxybenzoate as a color developer in place of bisphenol A in dispersions B to 1 of Example 2, and dispersion B-1 of Example 2 was prepared.
Four types of heat-sensitive recording paper were produced in the same manner using dispersion B-3 instead of the dispersion B-3, and the color development and sunlight exposure were performed in the same manner as in Example 2, and the degree of color was measured. The results are shown in Table 4.

Table 4 (Fluoran compound; 6-N-methyl-N-cyclohexylamino-6-methyl-7-phenylaminofluoran developer: benzyl 4-hydroxybenzoate) Flunotiazine 1.27 1.20 94
．． 5 Ratio Example 4 Dispersion in Example 2, g, 1 part by weight of A-1, 1 part by weight of Dispersion B-5 in Example 4, and 1 part by weight of Dispersion B-5 in Example 2 A flea powder was prepared by mixing the above, and this was coated on white paper and dried to produce heat-sensitive recording paper, which was colored in the same manner as above, and then exposed to sunlight to measure the color density.

The results are shown in Table 4.

Example 5 1 part by weight of dispersion A-1 of Example 2 and 2 parts by weight of dispersion B-2 of Example 3 were mixed (mixture A-B).

On the other hand, dispersion i C-2 of Example 2 and dispersion-D of Comparative Example 2
respectively 0:1.0.05:0.95.0.1:
They were mixed in weight parts of 0.9.0.2:08.0.5:0.5.1:0, and each was mixed with the above mixture i A-B to prepare six types of coating liquids. These coating solutions contain 3-
N-methyl-N-cyclohexylamino-6-methyl-
7-phenylaminofluorane:2-methoxyphenothiazine 1:0.1:0.05.1:0.1.1:0.
They meet in a ratio of 2.1:0.5.1:1.

These fallen cloth liquids were applied to white paper, dried, and applied to six types of heat-sensitive recording paper, which were colored in the same manner as Maenishi, and then exposed to sunlight for 4 hours.

The color 17 quality before and after exposure was measured in the same manner as above, and the results are shown in Table 5.

Table 5 i: 0 1.22 1.00 82
．． 01: 0.05 1.26 1.13
89.71: 0.1 1.26 1.
13 89.71: 0.2 1,27
1.19 93.71: 0.5 1.
1 1.26 96.91: 1
1.31 1.31 100.0
Example 6 Dispersion df in husband case 2: 6-I used for A-1;
-Methyl-J=J -7 Chlohexylamino-6-methyl-7-phenylaminofluoran instead of Tero-N-
Dispersion A-2 was made using ethyl-p-toluidino-6-methyl-7-phenylaminofluorane.

Dispersion A-2, Dispersion B-2 of Example 3 and Example 2
A coating solution was prepared by mixing Dispersion C-2 in a ratio of 1:2 to 1 parts by weight, and this was coated on white paper and dried to prepare thermosensitive recording paper. This was heated in the same manner as above to develop color, and then exposed to sunlight for 40 hours, and the color density before and after exposure was measured.

The results were as follows.

1.27 1.25 98.4 Example 7 5-N-ethyl-1 used in dispersion A-2 of Example B
1) 3-diethylamino-6-methyl-7 instead of -toluidino-6-methyl-7-phenylaminofluorane
- Dispersion A-3 was made using chlorofluorane - Dispersion A-5 was used instead of Dispersion A-2 used in Example 6.
The same experiment as in Example 6 was conducted using .

However, since the color of this fluoran compound is vermilion, a filter with thiazine≠58 was used when measuring the chromaticity. The measurement results are shown below.

Example 8 Using 3-N-methyl-N-inbutylamino-6-methyl-7-phenylaminofluoran as the fluoran compound, dispersion '[A-4] was prepared in the same manner as above.

1 part by weight of this dispersion A-4, 2 parts by weight of dispersion B-2 (4-hydroxy-4-isopropoxydiphenylsulfone dispersion) in Example 2, and dispersion C-1 (phenothiazine dispersion) in Example 2. A coating solution was prepared by mixing 1 part by weight of the dispersion), and a heat-sensitive recording paper was produced using this coating solution in the same manner as above. This thermosensitive recording paper was heated to develop color (black) in the same manner as in Example 2, and was exposed to sunlight for 50 hours, and the color density before and after exposure of the colored area was measured. The results are shown below.

t 33 1.20 97.0 Comparative example
5 Di-β-instead of phenothiazine in dispersion C-1
A dispersion thereof was prepared using naphthyl-p-phenylenediamine, and this dispersion was used in place of dispersion C-1 in Example 8 to produce thermal recording paper. This feeling
Agc: The recording paper was subjected to heat color development and sunlight exposure in the same manner as in Example 8, and the color density of the color development area before and after exposure was measured. The results are shown below.

Example 9 5-N-ethyl-N-isobutylamino-6-methyl-
2.02% of 7-phenylaminofluorane and 0.52% of phenothiazine were added to alkyldiphenylmethane (Nisseki Chemical Co., Ltd. [H1° Sol 5AS296J)] 25. Of and diisopropylnaphthalene (Kureha Chemical Co., Ltd. rxM
c-H3J) 18.02 was mixed and heated and dissolved (
A liquid).

On the other hand, sulfonic acid-modified polyvinyl alcohol (Nippon Gohsenol (KS-50)) +
7) 10% water m'1K15. Or, Polymer-maleic anhydride copolymer (Monsando rgMA-51)
Mix 7.5 t of 10% water fB solution and 34.0' of water, and further add 2.52 t of urea and 0.259 t of resorcinol.
After adding and dissolving P
) Adjusted to 13.4 (solution B).

Add solution A to solution B to make an emulsion using a homomixer, and then add 35% formalin aqueous solution 17. Of was added and stirring continued for 1 hour at a temperature of 60-65°C. 40C
After cooling, 28% ammonia water was added to adjust the ratio to 15 to obtain a microcapsule dispersion.

A coating liquid was prepared by mixing this dispersion 2Z02, wheat starch 6,57.8% wheat starch water soluble a8.5y, and water 34.0+++/.

This coating solution was applied to a white base paper using a wire bar (No. 12) and dried to prepare an upper sheet of pressure-sensitive copying paper.

The coated side of the upper sheet was placed on the coated side of the lower sheet for pressure-sensitive copying paper prepared by applying and drying a phenol-formalin resin, and color was developed by applying pressure between two rolls. The coated surface of the paper was colored black, and this black color was extremely durable against sunlight.

〔Effect of the invention〕

By incorporating a phenothiazine compound into a color-forming recording material containing a fluoran compound as a color-forming dye, it was possible to significantly improve the light resistance of a colored image of the color-forming recording material.

Above, the preparation and effects of color-forming recording materials containing phenothiazine compounds have been explained using an acidic substance as a color developer, but they can also be implemented in the same way and have the same effect even if other color developers are used. be effective.

Claims (1)

[Claims] A color-forming recording material composed of a fluoran compound-based color-forming dye and a color developer, in which a phenothiazine compound is contained in the image portion to be formed.