JPH01103484A - Coloring matter for 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 Application Field] The present invention can be effectively used in pressure-sensitive recording paper, heat-sensitive recording paper, ultraviolet-sensitive materials used in combination with organic halogen compounds, etc. using redox reactions. This invention relates to dyes for recording materials.

More specifically, the present invention relates to color-forming leuco dyes used in recording materials that develop color in response to various types of energy such as pressure, heat, electromagnetic waves (light), or particle beams.

[Conventional technology and problems]

In recent years, with the rapid spread of office automation, a large amount of information recording paper, such as pressure-sensitive recording paper, heat-sensitive recording paper, electrostatic recording paper, inkjet recording paper, etc., has fallen into use. Furthermore, the amount of thermal energy pattern forming materials used for various industrial or consumer purposes, such as dry film resists and inks for forming printed circuit boards, has increased in recent years. These various recording materials.

In response to energy such as pressure, heat, and electromagnetic waves, it undergoes a chemical change that involves a change in hue, from colorless to colored, or from colored to colorless, to form an image and achieve its purpose as a recording material. .

As a chemical means for forming such a distinguishable colored image, for example, in the case of information recording paper such as pressure-sensitive recording paper and heat-sensitive recording paper, basic leuco dyes such as phthalide or fluoran dyes and phenolic resins are used.・Color reaction by contact with organic or inorganic solid acids such as salicyl M derivatives or acidic clays is generally used.

These compounds quickly form color-forming complexes upon contact, producing various hues corresponding to each compound. However, the formation of this color-forming complex is reversible, and water, fats and oils, oxygen-containing polar organic The equilibrium shifts and the color disappears due to contact with solvents or temperature changes. Therefore, it has a major drawback in that the recorded image lacks stability against the environment, and there has been a strong demand for improvement. This kind of storage modification.

2 For the sake of improvement, the present inventors have developed a pressure-sensitive recording unit and a heat-sensitive recording unit (Japanese Patent Application Laid-open No. 57-1-1) using a novel redox coloring system.
07882, 5B-74389゜58-13268
7th grade) was proposed.

According to such a novel coloring method, a single color image is irreversibly formed on the recording paper, so that the instability of the color image described above can be eliminated. Compounds such as leuco crystal violet have been known for a long time as color-forming compounds used in this color-forming method, but leucotriphenylmethane dyes, which are represented by this compound, are However, there remained problems in controlling background color development during long-term storage before use and temperature control, and further improvements were needed.

[Means for solving problems]

In view of the above-mentioned problems, the inventors of the present invention have conducted intensive studies on a pigment for recording materials with excellent performance, and found that a pigment for recording materials represented by the general formula (1) has solved the above-mentioned problems. We have discovered that this is an excellent material that overcomes these problems, and have arrived at the present invention.

That is, the present invention is directed to the general formula (1) (wherein R1 represents an amino group or an alkoxy group which may be an alkyl group or a benzyl group, and R3 represents an alkyl group or an alkoxy group.

), X represents a l,4-biphenylene group, a 4,4-stilbenylene group, or a 4°,4''-1,4-distyrylbenzenylene group.

The dye for recording materials in the present invention is a pressure-sensitive recording paper using a redox reaction, a heat-sensitive recording paper, or an ultraviolet-sensitive material used in combination with an organic halogen compound, such as a dry film resist for printed circuit formation, a germicidal lamp decay indicator, etc. It is effectively used for such purposes.

Specifically, the dye for the recording material of the present invention is 4.4°
-bis(p,p'-bisdimethylaminodiphenylmethyl)diphenyl, 4.4°-bis(p,p'-bismethylamino-m,m'-dimethyldiphenylmethyl)
diphenyl, 4.4'-bis(p,p'- and sudiethylaminodiphenylmethyl)diphenyl, 4.4°-
Bis(p,p'-bismethylamino-m,m'-dimethoxydiphenylmethyl)diphenyl, 4,4'-bis(
p.

po-bisdimethylamino-o,o'-dimethyldiphenylmethyl)diphenyl, 4.4″-bis(p-aminophenyl-po-dimethylaminophenylmethyl)diphenyl, 4,4°-bis(p-methoxyphenyl) -p
o-dimethylaminophenylmethyl)diphenyl, 4.
4°-bis(p,p'-bisdimethylaminodiphenylmethyl)stilbene, 4.4°-bis(p,p''-bisdiethylaminodiphenylmethyl)stilbene, 4.
4°-bis(p-methoxyphenyl-p'-dimethylaminophenylmethyl)stilbene, 4°4°-bis(
p-7 minophenyl-p°-diethylaminophenylmethyl)stilbene, 4°.

4”-bis(p,p'-bisdimethylaminosiph)
enylmethyl) 1,4-distyrylbenzene, 4'.

4°°-bis(p, p'-bismethylamino-m.

m゛-dimethyldiphenylmethyl)1,4-distyrylbenzene, 4',4''-bis(p-methoxyphenyl-
po-dimethylaminophenylmethyl)1,4-distyrylbenzene, 4,4゛-bis(bis-1''-methyl-
2"-methylindol-3''-ylmethyl)diphenyl, 4.41-bis(bis-1"-ethyl-2"-methylindol-3"-ylmethyl)diphenyl, 4°4°-bis(bis-1 ″-ethyl-2″-methylindole-3″-ylmethyl-)stilbene, 4°, 4″-
Bis(bis-11°-ethyl-2per-methylindole-3perylmethyl)1,4-distyrylbenzene, 4
．． 4'-bis(p-methoxyphenyl-1''-ethyl-
2″-methylindol-3″-ylmethyl)diphenyl, 4゜4゛-bis(p-ethoxyphenyl-1″-butyl-2″-methylindol-3′-yl)diphenyl, 4.4°-bis( p-aminophenyl-1′-ethyl-2″-methylindole-3°-yl)stilbene, 4,4°-bis(P-methoxyphenyl-1″-ethyl-2″-methylindole-3″- yl) stilbene, 4.4°-bis(p-methoxyphenyl-1"-ethyl-2"°-methylindole-3"-ylmethyl)
Diphenyl, 4.4°-bis(1″-ethyl-2″-methylindol-3″-ylmethyl-)diphenyl.

4.4°-bis(p-aminophenyl-1″-ethyl-
2″-methylindol-3″-ylmethyl)stilbene or 4′,4″-bis(p-aminophenyl-
I l11-ethyl-2”°-methylindole31
-ylmethyl)1,4-distyrylbenzene, etc., but the dye for recording materials of the present invention is not limited to these examples.

The dye for recording materials of the present invention generally has the following general formula (I
II) dialdehyde and general (V) or general (VI
) with amine derivatives, or reaction of general (rV) with benzhydrol derivatives of general (V) or general (V[
) is synthesized by reaction with an amine derivative.

HCO-X-CHO (III) However, R1-R3 have the same meaning as R1-R3 in the above general formula. ) Various solvents are used as the medium for this reaction, but generally the reaction is carried out in an aqueous medium with 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. A condensation reaction is carried out, and unreacted substances are removed by subsequent alkalinization to obtain the desired product. 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-〇-toluidine, N-ethyl-
〇-Toluidine, N-methyl-O-anisidine, N-ethyl-〇-phenetidine, N,N-dimethyl-m-anisidine, N,N,-diethyl-m-anisidine, N,N
-dimethyl-m-)luidine, 1-methyl-2-methyl-indole, l-ethyl-2-methylindole, l
-butyl-2-methyl-indole, 1-octyl-2
-methyl-indole, 1-benzyl-2-methylindole, and the like.

Further, as the benzhydrol derivative of general formula (IV), 4.4°-bis(p-methoxy-α-oxybenzyl)diphenyl, 4.4″-bis(p-ethoxy-α-
oxybenzyl)diphenyl, 4゜4°-bis(p-methoxy-α-oxybenzyl)stilbene, 4゛, 4″
-bis(p-methoxy-α-oxybenzyl)1.4-
Distyrylbenzene, 4,4°-bis(p-amino-α
-oxybenzyl)diphenyl, 4,4'-bis-(p
-methylamino-α-oxybenzyl)stilbene, 4
°, 4″-bis(p-amino-α-oxybenzyl) 1
．． Examples include 4-distyrylbenzene.

-a The dialdehyde derivative of formula (III) is diphenyl-
4,4゛-dialdehyde, stilbene-4゜4゜-dialdehyde or 1,4-distyrylbenzene-4゜,4
”-dialdehyde.

The dye for recording materials of the present invention is 1, for example, JP-A-57-107
No. 882, No. 58-74389, No. 58-1326
As disclosed in No. 87, pressure-sensitive recording paper using an oxidation-reduction reaction, the coloring mechanism is estimated to be as follows upon contact with electron-withdrawing group-substituted benzoquinones used in pressure-sensitive and thermal copying papers. , causing rapid, deep and quantitative color development.

(In the formula, 1, Y is an electron-withdrawing group, and n means an integer of 1 to 4.) A colored product obtained by such a redox coloring method!
Because (■) has a long conjugated system, it often exhibits a deep hue that is not seen in conventional triarylmethane compounds, and in addition to diversifying the hue of recorded images, it also It has superior air oxidation resistance during storage compared to paper, so it reduces the tendency of coloring and staining the paper surface before use (
For example, discoloration of the surface coated with microcapsules in the case of pressure-sensitive recording paper is significantly reduced, making it possible to reduce or eliminate the use of anti-staining agents. In addition, since the coloring obtained in this way is irreversible, the stability of the image in the storage environment is very good, and it is possible to avoid the reaction between lactone dyes and acidic substances conventionally used in this field. There is almost no discoloration due to contact with water or polar organic solvents, as seen in 9 Pressure-sensitive or heat-sensitive recording materials constructed using a recording material dye represented by general formula (1) of the present invention and a quinone derivative. This is extremely useful from the viewpoints of preservation of color images and diversification of two color hues. It is also true that the system using this recording dye can significantly reduce the coloring caused by organic solvents or fingerprints, which is a drawback of thermal recording paper using redox or chelate coloring agents, and has high practical value. This is a remarkable feature of color-forming materials.

In addition, ultraviolet-sensitive materials constructed using the dye for recording materials of the present invention, particularly ultraviolet-sensitive materials produced by free radical photography using organic halogen compounds as color development aids, can be prepared using conventional leucotriarylmethane 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 material layer on the support and It has great advantages such as easy handling.

When producing a recording material using the dye of the present invention,
This can be carried out using various techniques known per se in the industry. That is, when preparing a pressure-sensitive recording material, the compound of the present invention is mixed with a suitable solvent such as phenylxylylethane,
Dissolved in a solvent such as alkylnaphthalene or hydrogenated terphenyl to a suitable concentration 9, e.g. 3% by weight, and microencapsulated gelatin by coacervation method or microencapsulation of e.g. melamine-formaldehyde membrane by 1n-situ polymerization method. and particle size 3
An aqueous dispersion of microcapsules containing a dye solution of about 10 μm is prepared, a binder and stilt are added, and the mixture is coated on high-quality paper to obtain a dye microcapsule-coated surface. When this is opposed to a developer surface obtained by coating a color developer, such as a dispersion of a polar group-substituted quinone, and a striking pressure is applied, an arbitrary image corresponding to the striking image quickly develops color.

To obtain a heat-sensitive recording material, a color developer, such as an aqueous dispersion of a polar group-substituted quinone (appropriately 1/2 to 4 molar ratio of the dye), and an appropriate melting point are added to an aqueous dispersion of the compound of the present invention which has been made into fine particles. Depressants (compounds commonly used in the art, such as higher fatty acid amides, aromatic acid esters or aromatic hydrocarbons, are advantageously applied within the range of commonly used amounts).

Phenolic compounds (e.g. bisphenol A).

-S etc. is used in an amount 1/2 to 4 times that of the dye. ), ultraviolet absorber, other auxiliaries, pigments, and binders (compounds commonly used in this field can be used). This is achieved by finishing such as smoothing.

The heat-sensitive recording material obtained in this manner exhibits color development with different heat sensitivity characteristics depending on the blended components.

To prepare the UV-sensitive coloring layer, the resin components commonly used for this purpose and the dyes of the present invention are dissolved in a suitable solvent together with a photosensitizer commonly used in this field, such as a halogenated aliphatic aromatic ketone, and the support Apply it on your body and let it dry. This is hot laminated with a polyethylene film to obtain a pattern mask for photoresist. Various other techniques known in the art can be applied.

[Example] Hereinafter, the present invention will be explained in detail with reference to Synthesis Examples and Examples. In the following, parts mean parts by weight.

Synthesis Example 1 Synthesis of 4.4°-bis(p,p'-bisdimethylaminodiphenylmethyl)diphenyl 1 part of diphenyl-4,4'-dialdehyde, 2.5 parts of dimethylaniline (slight excess), 4 parts of concentrated hydrochloric acid 1 part and 5 parts of water were stirred and boiled for 24 hours, then made strongly alkaline with aqueous caustic soda solution,
Unreacted dimethylaniline was removed by steam distillation to obtain a solid reaction product. This is extracted with xylene to drive out the xylene, extracted with ligroin, and after concentration, a small amount of xylene is added to dissolve the precipitate, and then allowed to cool to precipitate crystals. The strained fraction was recrystallized from xylene-ligroin, and the melting point was 19.
White crystals with a temperature of 7-199°C were obtained. The structure was confirmed by nine elemental analysis and nuclear magnetic resonance spectroscopy with a yield of about 50%. Do the same.

The reaction was carried out using stilbene-4,4°-dialdehyde, and 4,4゛bis-(p,p'-bisdimethylaminodiphenylmethyl)stilbene was obtained with a melting point of 198-200.
Obtained as pale yellow crystals at ℃.

Synthesis Example 2 Synthesis of 4°,47-bis(p-methoxyphenyl-11-ethyl-21-methylindol-31-yl)1,4-distyrylbenzene 4-methoxycarbonylbenzyltriphenylphosphonium bromide and terephthaldialdehyde 2 parts of 4°, 4"-bismethoxycarbonyl-1,4-distyrylbenzene was dissolved in 1 part of methanol.
A solution of 0.5 parts of caustic soda and 1 part of water is stirred and added dropwise little by little while boiling, and most of the solution is dissolved after 5 hours of reaction. During this time, 4 parts of water was added dropwise to make sure that no substance precipitated.Finally, 10 parts of water was added and heated to make the mouth liquid acidic with hydrochloric acid, and the precipitate was strained and dried. 1 part of the obtained carboxylic acid was mixed with 3 parts of phosphorus oxychloride, and then 1 part of phosphorus pentachloride was added.
．． Add 3 parts and boil under reflux for 1 hour to chloride, remove phosphorus oxychloride and excess phosphorus pentachloride under reduced pressure, add 5 parts of tetrachloroethane and 0.6 parts of anisole to the remainder, and add 0.8 parts of anhydrous aluminum chloride under water cooling. After stirring at room temperature for 1 hour, keep at 40℃ for 3 hours.Next, decompose with ice water, remove tetrachloroethane by steam distillation, strain the remainder, dry and extract with 0-dichlorobenzene. 4″
The crude product of -diassoyl-1,4-distyrylbenzene was obtained in a quantitative manner. 1 part of this ketone was mixed with 10 parts of butyl cellosolve, 0.5 parts of zinc powder, and 0.5 parts of caustic soda, 0.1 part of water was added, and the mixture was stirred and boiled for 7 hours.The strained mixture was heated and the remaining part was washed with methanol.

The mouth fluid and washings were combined and steam-distilled, the remaining solid was strained, and the remaining solid was dried. One part of this was mixed with 5 parts of methanol and 1-ethyl-2
- When mixed with 0.6 part of methylindole, heated and added as a solution with 0.05 part of concentrated hydrochloric acid, precipitation occurs immediately. After stirring under heating for 6 hours, the mixture is cooled, and the strained portion is washed with methanol and dried. The desired product was recrystallized from xylene as a slightly yellow powder that did not show a melting point even at 31 parts C.
% yield.

Synthesis Example 3 Synthesis of 4.4°-bis(bis-1″-ethyl-2″-methylindol-3″-ylmethyl)diphenyl 1 part of diphenyl-4,4°-dialdehyde was mixed with 20 parts of methanol and 1-ethyl When heating and dissolving 1.6 parts (slight excess) of -2-methylindole and adding 0.05 parts concentrated hydrochloric acid while stirring, a precipitate immediately occurs.After heating for about 3 hours and cooling, strain the precipitate. After washing with methanol and drying, the crude target product was obtained almost quantitatively. Purification turned into a pale yellow powder. Melting point: 175-177°C0 Below, examples of various compounds obtained by the above synthesis method are shown in the first
For convenience, the following abbreviations will be used to represent the compounds.

(Left below) Example 1 Preparation of pressure-sensitive recording paper Preparation of clay paper 2. 4,4゛-bis(p,
p'-bisdimethylaminodiphenylmethyl)diphenyl to phenylxylylethane SAS manufactured by Hon Petrochemical Co., Ltd.
296) to a weight concentration of 3%, and 130 parts of the resulting solution was dissolved in acrylamide-2'-methylpropanesulfonic acid,
It was added to 80 parts of an aqueous solution containing 6 parts of a copolymer of acrylic acid and acrylonitrile in a molar ratio of 2:15:9 and emulsified in a homomixer to form an O/W type emulsion with an average particle size of 3.5 μm. Then, while stirring, 25 parts of a methylated methylolmelamine resin aqueous solution (80% non-volatile content) was added, the temperature was raised to 60°C, condensation was carried out by stirring for 2 hours, and the mixture was cooled to obtain a microcapsule slurry (approximately 65% solids content). Furthermore, with 28% ammonia water, p) Is. The remaining formaldehyde was removed with O to obtain a microcapsule dispersion. The average particle size of the microcapsules was approximately 3.5μ. Using this dispersion, an aqueous coating solution having the following composition was prepared.

% (solid weight) Microcapsules 20 Oxidized starch (glue) 2.5 Stilt (starch particles) 8 This coating liquid was applied to high-quality paper at a dry coating weight of 4 g/rd, and a pressure-sensitive I got top paper for recording paper.

Preparation of the bottom paper: 2.5 dicyclohexyloxycarbonyl-3-benzylsulfonyl-1,4-benzoquinone (color developer) is stirred at high speed with microscopic glass particles in an aqueous solution containing a small amount of sulfonated styrene oligomer to atomize the particles. A fine dispersion liquid with a color developer content (weight) of 10% was obtained. Using this dispersion, an aqueous coating solution having the following composition was prepared.

% (solid weight) Kaolin 20 Color developer 0.8 Oxidized starch (glue)
1.5 50% SBR latex 3.0 This coating solution was applied to high-quality paper at a dry coating weight of 6 g/% to obtain a base paper for pressure-sensitive recording paper.

Color development 2 The coated sides of the top paper and the bottom paper are combined, and an IBM electric typewriter (IBM-65) is used to print the letter X continuously to develop the color. I got the results.

L value 72.45 a value -16.22 b (1
It was in u. Similarly obtained 4.4°-bis(p,
p'-dimethylaminodiphenylmethyl)stilbene and 4°.

The color images of 4″-bis(p,p″-bisdimethylaminodiphenylmethyl) 1,4-distyrylbenzene are all deep green, and the visible absorption maximums are both 640 and 490 m.
I wrote it with μ. No natural coloring tendency was observed on the coated surface of the upper paper.

Example 2 Preparation of thermal recording paper Preparation of recording paper: 4,4+-bis(p,p'-bismethylamino-m,m'-dimethyldiphenylmethyl)diphenyl (Compound No. 2 in Table 1) was added to 5% polyvinyl Stir at high speed with microscopic glass particles in an alcohol solution. An aqueous dispersion containing 10% micronized pigment bodies was obtained. 2,5-dicyclohexyloxycarbonyl-3-p- as a color developer
Using toluenesulfonyl-1,4-benzoquinone, 5
% polyvinyl alcohol aqueous solution to obtain a 10% dispersion of the color developer. Similarly, 20% of melting point depressant (β-naphthol benzoate) and bisphenol S
Dispersion (5% in polyvinyl alcohol aqueous solution), 20% aqueous dispersion of zinc stearate, 50% of calcium carbonate
An aqueous dispersion and a 25% aqueous dispersion of talc were prepared, and the following compositions were mixed and stirred well to obtain an aqueous coating solution. (The number in parentheses means solid weight % in total solid content.) Pigment dispersion 1 part (2.6%) Color developer dispersion
#(#) Bisphenol S dispersion #(5.2%) Zinc stearate dispersion 〃(l) Calcium carbonate dispersion 2 parts (26.0%) Talc dispersion 4
Part (#) Melting point depressant dispersion 4 parts (20.8%) 10% polyvinyl alcohol water? 8 liquid 2 parts (11.7%) This coating liquid was coated on high-quality paper so that the dry coating amount was 8 g/rrr to obtain heat-sensitive recording paper.

The heat-sensitive recording paper prepared on Color Development 2 was solid-colored (
The color measurement results of the obtained colored image using Σ80@ with an applied voltage of 20 V are as follows.

L value 52.02 a value -10,33 b value 1. The visual appearance of the Ol colored image is dark green, and the maximum absorption in the visible region is 620.
and 480 mμ.

Similarly, 4.4°-bis(p-methoxyphenyl-p
The color image of the thermosensitive recording paper obtained using o-dimethylaminophenylmethyl)diphenyl as the dye was red, and the absorption maximum in the visible region was 550 and 430 mμ. In addition, all of the colored images obtained here have excellent solvent resistance; for example, when salad oil was applied to the colored images and left at room temperature for 24 hours, almost no ground coloring was observed and no discoloration of the images was observed. .

Example 3 Preparation of ultraviolet coloring material l) Preparation of photoresist film Prepare a resin solution with the following composition.

Air-drying acrylic resin 70 parts (Mitsui Toatsu Chemical Almatex L-1042) Dipentaerythrit hexaacrylate 30 parts Hydroquinone (polymerization inhibitor) 0.1 part 4-phenoxydichloroacetophenone 3 parts 4.4'-bis (p, p'
- bisdimethylaminodiphenylmethyl) diphenyl (dye) 1 part Add ethyl acetate to this to adjust the viscosity.
It was coated on a polyester film with a dry thickness of 30 μm, and after drying at 105°C for 10 minutes, the dried film was
Hot laminated with mil-thick polyethylene film. The polyethylene film was removed from this sandwich film, and the exposed surface of the photoresist was laminated on the clean copper-clad 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 Arclight), in which the conductive pattern becomes a transparent area with an opaque background, was closely attached to the top, and an ultra-high pressure mercury lamp (manufactured by Oak Seisakusho) was used to irradiate ultraviolet light with an intensity of 150 mj/am''. However, the ultraviolet irradiated area was completely cured and exhibited a dark green color, and it was easily recognized that the image was formed according to the pattern of the pattern mask film on the laminate.

The unexposed areas were developed with chlorocene and etched with a cupric chloride solution, and the copper wiring was replaced according to the pattern.

On the other hand, when leuco crystal violet (4,4°, 4''-trisdimethylaminotriphenylmethane), which is commonly used for this purpose, is used as the dye, the varnish is significantly colored blue, and even after exposure to ultraviolet rays, there is no background. The contrast was insufficient.

2) Preparation of ultraviolet-sensitive sheet: 5 parts of a solution prepared by dissolving 10 parts of 4.4°-bis(p,p"- and dimethylaminodiphenylmethyl)stilbene in 190 parts of acetone, 35 parts of styrene, and butyl acrylate. Solid content: 45 parts, consisting of 60 parts and 5 parts of methacrylic acid.
% of styrene-acrylic copolymer emulsion and added Cyasolp UV-1084 (A
To 790 parts of an ultraviolet absorber-containing emulsion to which 1 part (manufactured by CC Corporation) had been added was added with stirring, and 5 parts of a solution of 10 parts of 4-phenoxydichloroacetophenone dissolved in 90 parts of acetone was added to make 100 parts of the composition. did. This composition was coated on high-quality paper with a basis weight of 100 g/nf so that the solid content coating amount was 20 g/nf, and dried at 105° C. for 15 minutes to obtain a UV-sensitive sheet. The ultraviolet-sensitive sheet was heated for 10 minutes at a distance of 1c11 using an irradiator (germicidal lamp GL-15 manufactured by Sankyo Denki Co., Ltd.) that emits ultraviolet light of 254 mμ.
When irradiated for seconds, the surface irradiated with ultraviolet light changes sharply and irreversibly to green, which is useful as a decay indicator for germicidal lamps. Instead of the compound of the present invention, for example, leucomalachite green (4,4 (bis-dimethylaminotriphenylmethane), W1! The coating solution discolored over time, and the coated paper also tended to discolor when stored under indoor light.

Applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, A and B are each independently ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R^1 represents an alkyl group or a benzyl group.) or ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R
^2 represents an optionally substituted amino group or alkoxy group, and R
^3 represents an alkyl group or an alkoxy group. ) is shown. X represents a 1,4-biphenylene group, a 4,4-stilbenylene group, or a 4',4''-1,4-distyrylbenzenylene group.