JPH0477671B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to dyes for recording materials. Specifically, the present invention relates to leuco compounds used in recording materials that develop color in response to various types of energy such as pressure, heat, electromagnetic waves (light), and particle beams. With the rapid spread of office automation, large amounts of information recording paper, such as pressure-sensitive recording paper, heat-sensitive recording paper, electrostatic recording paper, and inkjet recording paper, are being used as various recording materials. It became like that. Also, energy-sensitive pattern forming materials used for various industrial or consumer purposes,
For example, the amount of dry film resists, resist inks, and the like used for forming printed circuit boards has been increasing in recent years. These various recording materials are sensitive to energy such as pressure, heat, and electromagnetic waves to form images by causing chemical reactions that change the hue from colorless to colored or from colored to colorless. has achieved its purpose. For example, in the case of information recording paper such as pressure-sensitive recording paper and heat-sensitive recording paper, chemical means for forming such a distinguishable colored image include basic leuco dyes such as phthalide or fluoran dyes, and phenol. Color reaction by contact with organic or inorganic solid acids such as resins or acidic clays is generally used. However, upon contact, these compounds quickly form color-forming complexes and develop various hues corresponding to each compound, but the formation of this color-forming complex is reversible, and water, oils, fats, and other substances The equilibrium shifts due to contact with oxygen polar solvents or temperature changes, causing the color to fade. Therefore, there is a major drawback in that the recorded image lacks stability against the environment, and there has been a strong demand for improvement. In order to improve storage stability, the present inventors developed a pressure-sensitive recording unit and a heat-sensitive recording unit (Japanese Unexamined Patent Application Publication No. 107882/1983) using a new redox coloring method.
58-74389, 58-132687). According to such a novel coloring method, a colored image is irreversibly formed on the recording paper, and the above-mentioned instability of the colored image can be solved. As the color-forming compounds used in this color-forming method, there is a need for a group of even more excellent compounds. Furthermore, other items of energy-sensitive recording materials include UV-sensitive color-forming materials, such as dry film resists for printed wiring boards, resist inks, and other UV-detecting materials, such as germicidal lamp decay indicators. . Various coloring principles have been proposed for these UV-sensitive materials, but the most commonly used coloring method is a so-called free radical photography method using a combination of a leucotriphenylmethane compound and an organic halogen compound. However, leucotriphenylmethane pigments, such as leuco crystal violet, generally tend to be too sensitive to air oxidation during storage, resulting in background discoloration during long-term storage before use. However, there remained a problem in the control of color development sensitivity, and further improvements were required. In view of the above-mentioned problems, the present inventors conducted extensive studies on dyes for energy-sensitive recording materials with excellent performance, and found that the general formula () (In the formula, A, B, X, and Y each represent a phenyl group, a naphthyl group, or an indol-3-yl group that may have a substituent.A, B, X, and Y each represent a phenyl group or a naphthyl group. In the case of a group, it has at least one substituted amino group at the para position of -CH-, and may further have one or more lower alkyl group, lower alkoxy group, halogen atom or amino group as a substituent. The present invention has been achieved based on the discovery that the dye for recording materials represented by the following formula is an excellent dye that overcomes the above-mentioned problems. That is, the dye for recording materials of the present invention is represented by the above general formula (), and specifically, it is expressed in JP-A-57-107882, JP-A-58-74389, JP-A-58
Pressure-sensitive recording paper using a redox reaction as disclosed in No. 132687, heat-sensitive recording paper or ultraviolet-sensitive material used in combination with an organic halogen-containing compound,
For example, it is effectively used in dry film resists for forming printed circuits, germicidal lamp decay indicators, etc. The dye for recording materials of the present invention rapidly develops a deep color in pressure-sensitive copying paper and heat-sensitive copying paper by the coloring mechanism estimated as follows when it comes into contact with the benzoquinone derivative substituted with an electron-withdrawing group. and causes quantitative coloration. Coloring substances obtained by such redox coloring methods () have long conjugated systems, so many of them exhibit deep hues not seen in conventional triarylmethane compounds. It has a variety of hues and has superior air oxidation stability during storage compared to leucotriarylmethane compounds, so it reduces the tendency for color staining on the paper surface (in the case of pressure-sensitive paper, on the surface coated with microcapsules) before use. This makes it possible to eliminate or significantly reduce the use of antifouling agents. Moreover, irreversible color development occurs on pressure-sensitive copying paper or heat-sensitive recording paper obtained in this way due to contact with pressure or thermal energy.
The color image is very stable under the environment in which it is stored, and unlike the color image developed by the reaction between lactone dyes and acidic substances, which has been widely used in the past, the color disappears when it comes into contact with water or polar solvents. There are very few things. In addition, the colored image obtained by contact between certain lactone pigments, such as crystal violet lactone, and inorganic solid acids such as acid clay, has a natural tendency to brown, and the colored image completely disappears in a few days. On the other hand, such a tendency is not observed at all in the colored images produced by the above-described coloring method using the dyes of the present invention. The above-mentioned lack of environmental stability of colored images also applies to current thermal recording paper, which is a combination of lactone dyes and phenolic solid acids. The tendency of a colored image to fade due to contact with other materials is considered to be a major problem. However, thermal recording paper using a redox coloring system using a dye for recording materials represented by the general formula () of the present invention and a dibenzoylquinone derivative is not suitable from the viewpoint of storage stability of colored images and diversification of colored hues. Extremely useful. In addition, ultraviolet-sensitive materials constructed using the dye for recording materials of the present invention, particularly ultraviolet-sensitive materials using free radical photography with organic halide-containing compounds, can be prepared using conventional leucotriphenylmethane compounds, such as leuco crystals. Compared to UV-sensitive materials using violet, etc., it has much better heat resistance stability and indoor light stability before use, so it can improve the workability of coating the UV-sensitive layer onto the support.
It has major advantages such as easier handling before use. The dye for recording materials of the present invention can be prepared by reacting terephthaldialdehyde of the formula () with an amine derivative such as the formula () or () by the following method, or by reacting a benzhydrol derivative () of the formula () with the dye for recording materials of the present invention. It can be synthesized by reacting amine derivatives such as () and () with. Various solvents are used as the reaction medium, but generally the condensation reaction is carried out by carrying out the reaction in an aqueous medium using a mineral acid as a catalyst, or by heating for an appropriate period of time in an organic solvent such as methanol with a mineral acid as a catalyst. The desired product can be obtained by making it alkaline and removing unreacted substances.
Purification such as recrystallization is performed as necessary. The amine derivatives used in the reaction to obtain the dye for recording materials of the present invention include monomethylaniline,
Monoethylaniline, monobutylaniline, dimethylaniline, diethylaniline, N-methyl-
o-toluidine, N-ethyl-o-toluidine,
N-methyl-o-anisidine, N-ethyl-o-
Anisidine, N,N-dimethyl-m-anisidine, N,N-diethyl-m-anisidine, monobenzylaniline, N-methyl-N-benzylaniline, N-ethyl-N-benzylaniline, O-
Chloro-N-benzylaniline, diphenylamine, N-methyl-diphenylamine, 2,5-dimethyl-N,N-dimethylaniline, 2,5-dimethoxy-N-benzylaniline, N-methyl-
1-naphthylamine, 2-methoxy-1-N-methyl-naphthylamine, N,N-dimethyl-1-
naphthylamine, N,N-diethyl-1-naphthylamine, 1-ethyl-2-methylindole,
1-butyl-2-methylindole, 1-octyl-2-methylindole or 1-butyl-2
- Examples include phenylindole. In addition, as benzhydrol derivatives, 1,
4-bis-(α-oxybenzyl)benzene, 1,
4-bis-(α-oxy-4'-methoxybenzyl)
Examples include benzene, 1,4-bis-(α-oxy-4'-dimethylaminobenzyl)benzene, and the like. Specifically, the dyes for recording materials of the present invention include α, α, α', α'-tetrakis-(4'-methylaminophenyl)-1,4-xylene, α, α,
α',α'-tetrakis(4'-ethylaminophenyl)-1,4-xylene, α,α,α',α'-tetrakis-(4'-dimethylaminophenyl)-1,4
-xylene, α, α, α', α'-tetrakis-
(4'-diethylaminophenyl)-1,4-xylene, α, α, α', α'-tetrakis-(3'-methoxy-4'-ethylaminophenyl)-1,4-xylene, α , α, α′, α′-tetrakis(3′-methoxy-4′-methylaminophenyl)-1,4-xylene, α, α, α′, α′-tetrakis-(3′-methyl-4 '-ethylaminophenyl)-1,4-xylene, α,α,α',α'-tetrakis-(2'-methoxy-4'-dimethylaminophenyl)-1,4-
Xylene, α, α, α′, α′-tetrakis-(2′-
Methyl-4'-diethylaminophenyl)-1,4
-xylene, α, α, α', α'-tetrakis-
(4'-benzylaminophenyl)-1,4-xylene, α, α, α', α'-tetrakis-(4'-methylbenzylaminophenyl)-1,4-xylene,
α,α,α′,α′-tetrakis-(4′-ethylbenzylaminophenyl)-1,4-xylene, α,
α, α′, α′-tetrakis-(4′-ethylphenylaminophenyl)-1,4-xylene, α, α,
α′,α′-tetrakis(3′,6′-dimethyl-4′-
dimethylaminophenyl)-1,4-xylene, α,
α,α′,α′-tetrakis-(3′-chloro-4′-benzylaminophenyl)-1,4-xylene, α,
α,α′,α′-tetrakis-(3′,6′-dimethoxy-
4′-dimethylaminophenyl)-1,4-xylene, α,α,α′,α′-(3′,6′-dimethoxy-4
′−
benzylaminophenyl)-1,4-xylene,
α, α, α′, α′-tetrakis-(4′-methylamino-naphthyl-1′)-1,4-xylene, α, α,
α′,α′-tetrakis-(4′-dimethylaminonaphthyl-1′)-1,4-xylene, α,α,α′,
α'-tetrakis-(3'-methoxy-4'-methylaminonaphthyl-1')-1,4-xylene, α, α,
α′,α′-tetrakis-(1′-ethyl-2′-methylindol-3′-yl)-1,4-xylene, α,
α,α′,α′-(1′-butyl-2′-methylindol-3′-yl)-1,4-xylene, α,α′-bis(4′-dimethylaminophenyl)-α, α′-bis(4″-methoxyphenyl)-1,4-xylene,
α,α′-bis(3′-ethyl-4′-ethylaminophenyl)-α,α′-bis(4′-methoxyphenyl)
-1,4-xylene, α,α'-bis(3'-ethyl-4'-ethylaminophenyl)-α,α'-bis-
(4'-methoxyphenyl)-1,4-xylene,
α,α′-bis-(4′-dimethylaminophenyl)-
Examples include α,α'-bis-(1'-ethyl-2'-methylindol-3'-yl)-1,4-xylene. The dye for recording materials of the present invention is a pressure-sensitive copying paper or a heat-sensitive recording paper that uses a rapid and irreversible coloring reaction upon contact with a benzoquinone derivative, or an ultraviolet-sensitive color-forming material used in combination with an organic halogen compound. For example, it can be applied to printed circuit board forming materials, germicidal lamp indicators, etc. The recording material using the dye for recording materials of the present invention has greater resistance to air oxidation color development and greater thermal oxidation resistance than those using a leucotriallylmethane compound as a leuco compound. It is easy to handle, and its color development by pressure, heat, or ultraviolet light is quantitative and irreversible, and it has excellent environmental stability. In particular, when used as pressure-sensitive copying paper or heat-sensitive recording paper, it is important to develop color images in a reversible equilibrium state between the currently widely used triphenylmethane phthalide or fluoran compounds and acidic substances, and to improve storage stability. The difference is extremely large. When producing recording materials using these dyes of the present invention, various techniques known in the art can be used. Hereinafter, the present invention will be explained in detail with reference to Examples and Reference Examples. The text middle part means the weight part. Example 1 A mixture of 1.3 parts of terephthaldialdehyde, 5 parts of dimethylaniline and 10 ml of concentrated hydrochloric acid was heated and condensed with stirring for 12 hours, made alkaline by adding a 40% aqueous solution of NaOH, and steam distilled to remove volatile components and solids. and further recrystallized from O-dichlorobenzene to obtain α,α,α',α'-tetrakis-(4'-dimethylaminophenyl)-1,4- as a white powder with a melting point of 241.5-243.5°C. Obtained xylene. Example 2 1.3 parts of terephthaldialdehyde, 1-ethyl-
Add 0.1 part of concentrated hydrochloric acid to a mixture of 6.5 parts of 2-methylindole (slight excess) and 50 parts of methanol,
Mix and heat on an oil bath for an hour. After cooling, the white solid produced was filtered, washed with methanol, dried, and then recrystallized from O-dichlorobenzene to give a melting point of 254.
A white powder of α,α,α',α'-tetrakis-(1'-ethyl-2'-methylindol-3'-yl)-1,4-xylene was obtained at ~256°C. The elemental analysis values of this product were as follows. Elemental analysis value C H N Calculated value (%) 84.97 7.41 7.62 Actual value (%) 83.49 7.48 7.28 Example 3-10 According to Example 1, the following compound was obtained. Table 1 shows the obtained compounds and their melting points.

【table】

[Table] Reference Example 1 α,α,α′,α′-tetrakis-(3′-methyl-4′-benzylaminophenyl)- obtained in Example 8
Phenylxylylethane in which 3% by weight of 1,4-xylene was dissolved was microencapsulated by the known gelatin-carboxymethylcellulose complex corelation method to obtain a renucleated (grape bunch-shaped) average particle size of 8μ, solid content. A microcapsule suspension with a concentration of 18 wt% was obtained. 100 parts of this microcapsule suspension are mixed with 5 parts of wheat starch granules with an average particle size of 15 μm and 5 parts of a boiled oxidized starch solution with a concentration of 20% to form a uniform coating liquid, and the coating liquid is applied onto pressure-sensitive copying paper. with a Mayer bar coater, and the dry coating amount was 5.
g/m ² pressure-sensitive copying paper was obtained, and this was
- Di-ethoxycarbonyl-3,6-di-p-tolylsulfonyl-1,4-benzoquinone was used in combination with pressure-sensitive copying paper bottom paper containing as a color developer component, and when the color was developed by pressing, the color quickly turned dark green. A deep colored image with a maximum absorption wavelength of 605 mμ was obtained. The oxidized irreversible colored image thus obtained was extremely stable against the environment, and showed no tendency to disappear due to contact with polar solvents such as plasticizers or heating. In addition, compared to leucotriarylmethane compounds, it generally has better resistance to air oxidation color development during storage, and stabilizers such as There was no need to use triethanolamine or the like. Reference Example 2-6 The same procedure as in Reference Example 1 was used except that the compounds of Examples 1-4 and 9 were used, respectively, to form microcapsules, and then pressure-sensitive copying paper was obtained. This is 2,5-di-i-butoxycarbonyl-3,6
- When the color was developed using a typewriter in combination with pressure-sensitive copying paper bottom paper containing di-p-tolylsulfonyl-1,4-benzoquinone as a color developer, dark colors with the hues shown in Table 2 were immediately developed. The image was obtained.

[Table] All the colored images were extremely stable in the environment, and no tendency to disappear due to contact with aqueous solvents was observed. Furthermore, no tendency for natural coloring on the surface of the upper paper microcapsules was observed. Reference example 7 α, α, α′, α′-tetrakis- obtained in Example 1
(4'-dimethylaminophenyl)-1,4-xylene using α, α, α', α'-tetrakis-(4'-dimethylaminophenyl)-1,4-xylene 10 parts 10% polyvinyl alcohol Sand milling is carried out with a composition of 20 parts water and 20 parts of microparticles.
% aqueous suspension was obtained. On the other hand, 2,5-dibenzoyl- as a color developer
20% obtained by similar treatment of 1,4-benzoquinone
A water-based paint having the following composition was prepared using the aqueous suspension. parts (dry solid content) α,α,α′,α′-tetrakis-(4′-dimethylaminophenyl)-1,4-xylene 1.3 2,5-dibenzoylquinone 2.0 Stearamide 1.0 Zinc stearate 0.5 Precipitated calcium carbonate 5.0 Polyvinyl alcohol 1.3 The above water-based paint was coated on heat-sensitive base paper made from neutral paper using a bar coater so that the dry coating amount was 6 g/m ² and dried to prepare heat-sensitive recording paper. A voltage of 20 V and a pulse width of 1.4 msec was applied to this recording paper using a dot printer having a thermal head to obtain a green thermosensitive color image. This color image is deep green, and the maximum absorption wavelength is 430 mμ.
The color image thus obtained has excellent solvent resistance and light resistance, and is useful for applications such as POS heat-sensitive labels and heat-sensitive commuter passes that require severe usage conditions. Reference Example 8-11 The compounds of Examples 2, 5, 6, and 10 were treated in the same manner as in Reference Example 7 to obtain heat-sensitive recording paper and develop color. The hues are shown in Table 3.

[Table] All of them developed deep dark colors and had extremely excellent environmental fastness. Reference example 12 Air-drying acrylic resin (Mitsui Toatsu Chemical Almatex L-1042) 70 parts dipentaerythritol hexaacrylate
30 parts Hydroquinone (polymerization inhibitor) 0.1 part 4-phenoxy-dichloroacetophenone 3 parts α, α, α', α'-tetrakis-(4'-dimethylaminophenyl)-1,4-xylene 1 part The varnish obtained by mixing and dissolving the following and adjusting the viscosity by adding ethyl acetate was applied onto a 1 mm thick polyester film to give a dry thickness of 30μ, dried at 105℃ for 10 minutes, and then dried. The membrane was hot laminated with 1 mil thick polyethylene film. The polyethylene film of the above-mentioned sand-chilled photoresist was removed, and the exposed surface of the photoresist was laminated on the clean copper surface of a copper-clad laminate (manufactured by Universal Oil Products), and pressed with a rubber cover roll to make it adhere. . A high-contrast film (Diazo film manufactured by Arklight Co., Ltd.) whose conductive pattern becomes a transparent area of the opaque pack ground is adhered to the top, and then an ultra-high pressure mercury lamp (manufactured by Oak Seisakusho) is used to heat the film at 150°C.
When irradiated with ultraviolet light at an amount of mj/cm ² , the ultraviolet-exposed areas were completely cured and developed a deep green color. It was easily recognized that the pattern was formed according to the pattern of the colored patterned mask film on the laminate. When the unexposed portion was subjected to chlorocene phenomenon and further etched with a ferric chloride solution, a copper wiring according to the pattern was obtained. On the other hand, α, α, α′, α′-tetrakis-
When leuco crystal violet (4,4',4''-trisdimethylaminotriphenylmethane), which is officially used for the purpose, is used instead of (4'-dimethylaminophenyl)-1,4-xylene, , the varnish was extremely blue-colored and the ultraviolet-exposed image had insufficient contrast with the background, making identification difficult. Reference Example 13 190 parts of acetone was mixed with α, α, α', α'-tetrakis-(2, 5-g of a solution prepared by dissolving 10 parts of 5-dimethoxy-4-benzylaminophenyl-1,4-xylene, 35 parts of styrene as a matrix,
To 99 parts of a 45% solid styrene-acrylic copolymer emulsion consisting of 60 parts of butyl acrylate and 5 parts of methacrylic acid, 1 part of Cymasorb UV-1084 (manufactured by Cyanamid, USA) as an ultraviolet absorber was added in advance. 100 g of a composition was obtained by adding 5 g of a solution of 10 parts of 4-phenoxy-dichloroacetophenone as a free radical reactant dissolved in 90 parts of acetone to 90 g of the ultraviolet absorber-containing emulsion prepared above with stirring. . This composition was applied to a high-quality paper with a basis weight of 100 g/m ² so that the solid content amount was 20 g/m ² and heated at 105°C.
The film was dried for 1.5 minutes to obtain a UV-sensitive sheet. The UV-sensitive sheet was irradiated with UV rays with a wavelength of 254 mμ (Mitsui Electric KK germicidal lamp GL-15).
When irradiated for 10 seconds at a distance of 1 cm using a
The ultraviolet irradiated surface turned green sharply and irreversibly. This is useful as a decay indicator for germicidal lamps. α,α,α′,α′-tetrakis-(2,5-dimethoxy-4′-dimethylaminophenyl)1,4-
When leucomalachite green (4,4'-bis-dimethylaminotriphenylmethane) is used instead of xylene, the coating liquid has a strong tendency to discolor over time, and the coated paper also discolors during storage under indoor light. A trend was observed.

Claims (1)

[Claims] 1 General formula () (In the formula, A, B, X, and Y each represent a phenyl group, a naphthyl group, or an indol-3-yl group that may have a substituent.A, B, X, and Y each represent a phenyl group or a naphthyl group. In the case of a group, it has at least one substituted amino group at the para position of -CH-, and may further have one or more lower alkyl group, lower alkoxy group, halogen atom or amino group as a substituent. ) A dye for recording materials.