JPS63272581A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material containing coloring matter having absorption in visible area and near infrared area, by adding at least one kind of 1,1,3,5,5-pentaphenyl-1,4-pentadien compounds as a coloring agent then bringing the coloring agent into contact with an electron receptive material and exhibiting color. CONSTITUTION:At least one kind of 1,1,3,5,5-pentaphenyl-1,4-pentadien compounds shown by formula (1) is added as a coloring agent. The compound is a colorless or faintly colored leuco pigment which exhibits color when being brought into contact with an electron receptive material such as phenol formalin type resin, salicylic acid metal salts, bisphenols, clay mineral such as attapulgite, silty clay and when being brought into contact with an oxidizing agent such as chloranil. In any case, a coloring image having absorption in visible area of 500nm-700nm and in near infrared area of 700nm-900nm in some case can be formed.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention develops color upon contact with an electron-accepting substance such as an inorganic acid, an organic acid, a phenolic compound, a derivative thereof, or an oxidizing agent. The present invention relates to a recording material containing a novel leuco dye having absorption in the near-infrared region.

"Problems to be solved by conventional techniques and inventions" Recording materials using leuco dyes include pressure-sensitive recording materials,
Various materials such as heat-sensitive recording materials are known, but with the recent spread of computers and other devices in society, the demand for them has increased.
The number is likely to increase further in the future.

In general, what is called a pressure-sensitive recording material is basically made up of two sheets: a sheet coated with pressure-sensitive bursting microcapsules containing a solution of a leuco dye in an organic solvent, and a sheet coated with an electron-accepting substance. A recorded image is obtained by applying pressure from a ballpoint pen, etc., or impact pressure from a typewriter, etc. Also, what is a heat-sensitive recording material? A leuco dye and a color developer such as an electron-accepting substance are mixed and coated on a support sheet, and an image is recorded by thermally applying an image signal to the support sheet using a thermal head or the like. It is something.

As described above, pressure-sensitive and
Traditionally, the main purpose of heat-sensitive recording materials has been to obtain visible images.

As leuco dyes that can be used for these purposes, dyes with various structures have been proposed and put into practical use, such as phthalides typified by crystal violet lactone (CVL), fluorans having substituted amino groups, and spiropyrans.

CVL is heavily used as a typical pigment for obtaining clear gastric colors, but due to the poor light resistance of colored images, it is slow to develop colors like penzoylleucomethylene B#- (BLMB).
It is common practice to use a dye that provides a colored image with good light resistance.

The dye provided by the present invention is a new leuco dye that develops color slowly like BLMB, but develops in blue light and has excellent light fastness of a colored image. Although BLMB has excellent light resistance of colored images, it has a strong tendency to gradually become colored in the solution state.
In particular, when used in pressure-sensitive recording paper, the amount used must be limited, and there has been a need to develop alternative dyes.

On the other hand, with the recent progress in the development of light sources such as semiconductor V-zers, optical character reading devices (0, C, R,), etc.
It has developed and become popular, and is also used as a leuco dye for pressure-sensitive and heat-sensitive recording.
Leuco dyes that provide color images that absorb not only in the visible region but also in the near-infrared region have been sought so that reading with 01C0R0 and the like is possible.

Dyes and pigments that absorb in the near-infrared region are well-known, such as dyes and pigments that absorb in the near-infrared region, such as phthalocyanines, quinacridone, and other metal chelate compounds, but these themselves also have large absorption in the visible region. Because it has absorption, it cannot be used as a dye for pressure-sensitive or heat-sensitive recording using normal methods.

In order to use it for this purpose, it is necessary that it has a so-called leuco structure, which is colorless or pale in color, but can give a coloring structure when it comes into contact with an electron-accepting substance. is necessary.

Conventionally, several proposals have been made regarding leuco dyes that absorb in the near-infrared region.

For example, JP-A-51-121035, JP-A-51-1
No. 21037, JP-A-51-121038, JP-A-5
Divinyl-containing phthalide disclosed in JP-A No. 1-167979, JP-A-58-157779, JP-A-60-
Subirof μ-olene phthalide disclosed in No. 226871 and Japanese Patent Application Laid-open No. 61-22076 is said to be a dye capable of achieving the above-mentioned purpose.

In all of these conventional proposals, a leuco dye is created by adding a phthalide structure to the dye structure. The present invention is a leuco dye that is completely different from these known compounds, and is normally colorless or light-colored, but it develops color when it comes into contact with an electron-accepting substance, and some of them are visible. The object of the present invention is to provide a recording material containing a novel dye that has absorption not only in the near-infrared region but also in the near-infrared region.

"Means and effects for solving the problems" That is, the present invention is expressed by the following general formula [1], 1.3.5.
This is a recording material characterized by containing at least one type of 5-pentaf22/L/-1.4-pentadiene compound as a coloring agent.

[Here, R1, R2, R3, and R4 are an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 6 members, and a cycloalkyl group having 10 carbon atoms.
represents the following ary group, or ethylene,
Represents an alkylene group selected from propylene, trimethylene, etc. In the case of an alkylene group, the other end that is not bonded to the nitrogen atom is bonded to the benzene nucleus carbon corresponding to the 1-position of the nitrogen atom, or the other ends of R1 and R2 are bonded together, or R3 and R4 are bonded together at the other ends to form a ring. t, xi, x% x8
．． x4 Ha, 3H: (R'', R'tli' prime number 1
-6 alkyl group, 5-6 membered ring cycloalkyl group, allylalkyl group having 10 or less carbon atoms, or alkylene group selected from ethylene, propylene, trimethylene, etc. In the case of an alkylene group, the nitrogen atom The other end that is not bonded is bonded to the benzene nucleus carbon corresponding to the 1-position of the nitrogen atom, or the other ends of R6 and R'' are bonded together to form a ring.

), an alkyl group having 1 to 12 carbon atoms, a benzyl group, an alkoxy group having 1 to 12 carbon atoms, a benzyloxy group, hydrogen, chlorine, and a group selected from bromine (however, in the case of X'' and X', hydrogen is excluded) ), r and s are hydrogen, alkyl μ having 1 to 6 carbon atoms
represents a group selected from a group and an alkoxy group having 1 to 6 carbon atoms. Further, n represents an integer from 1 to 4. ] The compound [1] of the present invention is colorless or light-colored itself and can be regarded as a so-called leuco dye.

This compound is composed of phenol-formalin resin, salicylic acid metal salts, and bisphenols.

It develops color when it comes into contact with electron-accepting substances such as clay minerals such as attapulgide and diruton clay, and it also develops color when it comes into contact with oxidizing agents such as chloranil.
In either case, a colored image is formed that has absorption in the visible region of 500 nm to 700 nm, and in some cases also in the near-infrared region of 700 nm to 900 nm.

Therefore, if this compound is used as a pressure-sensitive or heat-sensitive recording material, the characters, marks, etc.
It is also possible to read C, R, ) and e.

Although any route may be used to obtain the compound [1] of the present invention, it can be obtained, for example, by the following reaction route.

Each means father-in-law. ] Compounds 1, 2, and 3 all belong to 1,1-diphenylethylene derivatives, and are generally synthesized using a Grignard reaction.

(5) (2) or [3] (
In the formula, A represents A or A, B represents B1 or B2, and X represents 01% Br. ) In this reaction, the benzophenone derivative [5] is reacted with a Grignard reagent, and a high-yield, high-quality ethylene derivative can be obtained very easily.

Furthermore, the ethylene derivative convex H3 [6] having the structure of formula [6] (where Rt and R1 are the same as above) can also be obtained by the method disclosed in JP-A-61-93143. can.

(In the formula, R1 and RM are the same as described above.) Target compound (R is the ethylene derivative (2) obtained by K as described above). In polar solvents such as alcohol-based solutions such as 1K, ethylene glycol-μ, diethylene glycol with lower alkoxy-substituted ethers, or cyclic ethers such as tetohydropone and dioxane, minerals such as hydrochloric acid and sulfuric acid. acids, fatty acids such as formic acid, acetic acid, propionic acid, methanesulfonic acid, P-)/L/ence~
It can be easily obtained by condensation with compound [4] in the presence of an organic sulfonic acid such as fonic acid or an acid catalyst such as a benzoic acid derivative.

If turtles of the same species are used as (2), (3) or [6], a symmetric structure will be obtained as [1], and if a different species is used, an asymmetric structure will be obtained as [1].

In producing a pressure-sensitive recording material using the compound of general formula [1], known methods can be used. For example, U.S. Pat.
A method such as that described in 79g of Core 7 Rubesi may be employed.

Furthermore, in order to manufacture the heat-sensitive recording material, for example, a known method described in Japanese Patent No. 14089/1989 can be employed.

In producing these recording materials, it is of course possible to use the compound of general formula [1] alone, but its usefulness as a recording material can be increased by co-using it with conventionally known color-forming compounds. It can be mixed with various compounds depending on the purpose.

"Examples, etc." Hereinafter, examples of synthesis of the compound of general formula [1] will be shown, and examples of recording materials using the same compound will be listed.

Synthesis Example 1 Add 1,1-bis(4-dimethyaminophenylv)ethylene 266F, 2,4-dioctoxybenzaldehyde 181f, and p-)luenesulfonic acid 1f to Butano-A/IJII at 70°C for 20 hours. Heated.

Upon cooling, a tar-like product precipitates out. After removing the supernatant liquid, tetrachloroethylene 11° activated carbon and activated clay were added to decolorize the mixture, and the mixture was concentrated.

The precipitated crystals were recrystallized twice using ethanol to obtain 108 g of yellow crystals. This color developed slowly on silica gel in the cobalt micrometer range, and the K emission spectrum showed a wavelength of 630 nm.

Synthesis Example 2 Butano-A/IJ, 1,1-bis(4-dimethylaminophe=lv)ethylene 266f, 2-octoxy-4
-dimethylaminobenzaldehyde 139 f.

Process p-toluenesulfonic acid 1f to 18.5 at 70℃
heated for an hour.

Methanol/I/41 was added to the reaction mixture and cooled, and the precipitated crystals were collected in a furnace.

The solution was dissolved in a mixed solvent of ethanol-μ and ethyl acetate, decolorized with activated carbon and activated clay, cooled, and the precipitated crystals were collected in a furnace.

It was dissolved in a small amount of acetone and discharged into methanol to obtain yellow crystals 64F. (It is amorphous and does not show a clear melting point.) It developed a deep deep color on the silica gel, and the reflection spectrum μ was χmgz 690 nm and 830 nm.

Synthesis Example 6 In 300 gJ of toluene, 29.6 f of 1,1-bis(4-dimethyaminophe=lv) ethylene, 2.4-
Add 11.4jF of dichlorobenzaldehyde, raise the temperature to 60℃, dropwise add 15.3F of phosphorus oxychloride, and heat to 80℃.
! S hr8 reacted.

After draining the reaction mixture into water, neutralize it with caustic soda and add toluene 2
00d was added, the liquid was separated, activated carbon and activated clay were added to the Toluev layer, decolorized, and concentrated to 7011d.

After cooling, the precipitated crystals were dried and re-crystallized with ethyl acetate to obtain 215 g of pale yellow crystals. (mp226.5℃)
.

II It developed a dark green color on silica gel, and the reflection spectrum showed a λman of 630 nm.

Synthesis Examples 4 to 12 Compounds [1] synthesized in the same manner as Synthesis Example 1 are summarized in the following table.

Example 1 Compound 7y obtained in Synthesis Example 1 was dissolved in monoisopropylbiphenyN98fK, and a solution prepared by dissolving gelatin 249 and gum arabic 241 in 400 cc of water and adjusting the pH to 7 was added to this solution and emulsified with a homogenizer. 1000 f of warm water was added to this emulsion and stirred at 50°C for 30 minutes. Next, dilute acetic acid was gradually added to adjust the pH to 4.5, and the mixture was stirred at 50°C for 1 hour, then cooled to 0''-5°C and stirred for an additional 30 minutes. Then, 4% gel tar aldehyde aqueous solution 859 was gradually added. In addition, the capsules were hardened, and then the pH was adjusted to 6 with a dilute aqueous caustic soda solution, and the encapsulation was completed by stirring at room temperature for several hours.During this operation, no coloring phenomenon occurred.

This capsule liquid was uniformly applied to paper using a wire bar and dried to obtain capsule-coated paper (upper paper).

Using this paper as a color developer, paper (lower paper) K coated with activated clay was placed one above the other, and when written with a ballpoint pen, a bluish-purple image slowly appeared on the lower paper. This image showed excellent light resistance, and measurement of the reflection spectrum showed an absorption maximum at 630 nm.

Example 2 8 g of the compound obtained in Synthesis Example 2 was added to a 10'% aqueous solution of polyvinyl chloride (PTA-105 manufactured by Kuraray Co., Ltd.).
) and 6.51 water and mixed and ground in Ball Mill μ for 20 hours to obtain "component A". The particle size of the pigment after milling was 5-5 microns.

On the other hand, 3.51 screw 7 z / -IL/A 15p
ion polyvinyl alcohol aqueous solution and 6.51 water were similarly mixed and pulverized in a Beau μ mill until the particle size became 3 to 5 microns to obtain "component B."

Next, Component A of α3F and Component B of 6.71 were mixed, dried, coated on high-quality paper with a wire spar so that the solid content was 6 fi/yf, and dried to obtain heat-sensitive recording paper.

This thermal recording paper has no capri, is cream colored,
It developed color when heated with a hot vent, etc., giving a dark blue image.

This image shows excellent light resistance, with a reflection spectrum μ of 690
It showed maximum absorption at 835 nm and 835 nm.

"Effects of the Invention" The present invention provides a structurally completely new leuco dye.
．． 1.3.5.5-pentaphenylene/L/-1.4-pentadiene compound is used to make it possible to provide a recording material that can replace the conventional color-forming recording material using p-leucomethylene p- It is.

Claims (1)

[Claims] (1) 1, 1, 3, 5, represented by the following general formula [1]
A recording material comprising at least one 5-pentaphenyl-1,4-pentadiene compound as a coloring agent. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [1] [Here, R^1, R^2, R^3, and R^4 represent the number of carbon atoms of 1
~6 alkyl group, a cycloalkyl group with a 5- to 6-membered ring, an allylalkyl group having 10 or less carbon atoms, or an alkylene group selected from ethylene, propylene, and trimethylene; in the case of an alkylene group, it is bonded to a nitrogen atom. The other end that is not connected is bonded to the benzene nucleus carbon corresponding to the ortho position of the nitrogen atom, or the other ends of R^1 and R^2 or the other ends of R^3 and R^4 are bonded to form a ring. Form. Also, X
^1, X^2, X^3, Represents a cycloalkyl group, an allylalkyl group having 10 or less carbon atoms, or an alkylene group selected from ethylene, propylene, and trimethylene; in the case of an alkylene group, the other end not bonded to the nitrogen atom corresponds to the ortho position of the nitrogen atom. (bonds with benzene nucleus carbon or bonds with the other ends of R^5 and R^6 to form a ring), alkyl group having 1 to 12 carbon atoms, benzyl group, alkoxy group having 1 to 12 carbon atoms , benzyloxy group, hydrogen,
A group selected from chlorine and bromine (however, hydrogen is excluded in the case of X^3 and represents a group selected from 6 alkoxy groups. Further, n represents an integer from 1 to 4. ]