JPS61241750A - Formation of image by silver salt diffusion transfer - Google Patents

Abstract

PURPOSE:To obtain an image of a desirable jet black tone by using an N-contg. heterocyclic mercaptan compd. substd. by a sulfo or carboxy group. CONSTITUTION:The image is formed in the presence of one of compds. represented by formula I, preferably, embodied by formula I-1, and it is used, optimally, in an amt. of 0.001-0.2g per 100g of the compsn. to be processed, optimally, in an amt. of 0.0003-0.1g/m<2> for a photosensitive element, and optimally, in an amt. of 0.001-0.2g/m<2> for an image receiving element. A developer is used, optimally, in an amt. of 1-20g per 100g of the processing soln.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image forming method by silver salt diffusion transfer and a film unit used therein.

(Prior Art) An image forming method by diffusion transfer using a silver salt such as silver halide is well known.Explaining this method in terms of a medium, for example, an image-exposed photosensitive silver halide emulsion layer is transferred to a developer. and an alkaline aqueous solution containing a silver halide solvent, and the exposed silver halide grains are reduced to silver by a developer, while the unexposed silver halide grains are converted into a transferable silver complex salt by the silver halide solvent. The silver complex salt is diffused and transferred by a silver precipitant-containing layer (an image-receiving layer) overlaid with the emulsion layer, and then the silver complex salt is reduced with a developer with the help of the silver precipitant to form a silver image. It consists of gaining something.

When carrying out this method, for example, a light-sensitive element having a light-sensitive silver halide emulsion layer on a support, an image-receiving element having an image-receiving layer containing a silver precipitant on a support, a developer, a halogenated A film unit is used which combines a processing element consisting of a breakable container containing an active alkaline aqueous solution containing a silver solvent and a thickener. First, the emulsion layer of the light-sensitive element is exposed imagewise, and then the light-sensitive element and the image-receiving element are overlapped so that the emulsion layer and the image-receiving layer of the image-receiving element face each other. The image-receiving element is passed between a pair of rollers so as to be developed, and after being left for a predetermined period of time, the image-receiving element is peeled off from the photosensitive element, thereby obtaining a print in which a desired image is formed on the image-receiving layer.

In diffusion transfer methods that use silver salts such as silver halides, the silver image is generally not black (but is known to exhibit brown or other unacceptable colors). Toning agents are used to overcome the drawbacks of transfer methods.

A typical example of a conventionally known coloring agent is l-phenyl-
! -mercapto/, J, J, Hiro-tetrazole is known. In addition, U.S. Patent No. J, 7J4.121
It has been reported that the S -substitution venic bubble Ij mijin derivative described in the issue is known to give a damp image with a high optical concentration.

(Problems to be Solved by the Invention) The color tone of the silver image formed in this way greatly affects the image quality, but the color tone of images currently used on the market is not necessarily desirable. , its improvement is desired.

Gives an image with a jet black tone and reduces the metallic luster of the image.
No satisfactory toning agent has been obtained that increases the maximum density.

(Object of the Invention) An object of the present invention is to provide a novel image forming method using silver salt diffusion transfer.

Another object of the present invention is to provide a method for providing a desirable jet-black image.

(Means for Solving the Problems) Therefore, as a result of intensive study on a method of improving color tone using a new color toning agent, the present inventors found that By using a mercaptan compound, the above objectives were achieved.

That is, the image-exposed photosensitive silver halide emulsion layer is developed in the presence of a developer, a silver halide solvent, and an alkali to convert at least a portion of the unexposed silver halide in the emulsion layer into a transferable silver complex salt. , in an image forming method by silver salt diffusion transfer, which includes transferring at least a portion of the complex salt to an image receiving layer containing a silver precipitant to form an image on the image receiving layer, in the presence of a compound represented by the following general formula. This was achieved by an image forming method using silver salt diffusion transfer, which is characterized by forming an image.

General formula % Formula %) In the formula, X represents a -N-1 heptalene atom, a sulfur atom, or an oxygen atom, and R2 represents a hydrogen atom or an alkyl group.

R1 represents a substituent, 2 represents an atomic group necessary to form a carbocycle or a heterocycle, Y represents a carboxyl group or a sulfo group,
M is a hydrogen atom, an alkal metal atom, μ class ammonium,
or represents μ-class phosphonium, m represents an integer of 1 to 3, and n represents an integer of O-co.

The carbocycle or heterocycle formed by 2 in the general formula may be, for example, a j-membered ring, a 7-membered ring, or a 7-membered carbocycle, or one or more nitrogen, oxygen, or sulfur atoms, etc. A j-membered ring containing a j-membered ring or a 7-membered heterocycle, and these carbocycles or heterocycles also include those forming a fused ring at an appropriate position. Examples thereof include a naphthalene ring, a pyridine ring, a pyrimidine ring, a middle norine ring, a yne middle norine ring, and the like.

R2 in the general formula represents a hydrogen atom or an alkyl group, preferably a hydrogen atom.

The substituent represented by R1 in the general formula is a 19-logogen atom (CF, ct, By, etc.), a substituted or unsubstituted alkyl group (methyl group, ethyl group, etc.),
Substituted or unsubstituted aryl group (phenyl group, p-chlorophenyl group, etc.), substituted or unsubstituted alkoxy group, aryloxy group (methoxy group, methoxy group, phenoxy group, etc.), sulfonyl group (methanesulfonyl group, p-toluenesulfonyl group), sulfonamide group (methanesulfonamide group, benzenesulfonamide group, etc.), sulfamoyl group (diethylsulfamoyl group, unsubstituted sulfamoyl group, etc.), carbamoyl group (unsubstituted sulfamoyl group, etc.) substituted carbamoyl group, diethylcarbamoyl group, etc.], amide group (acetamido group, benzamide group, etc.), ureido group (methylureido group, phenylureido group, etc.), dicarbonylamino group in aryloxy or alkoxy group (meth=r dicarbonylamino group, Examples include phenolic dicarbonylamino groups, etc.), aryloxy or alkoxy dicarbonyl groups (methoxycarbonyl groups, phenolic carbonyl groups, etc.), cyano groups, hydroxyl groups, carboxylic groups, sulfo groups and nitro groups.

m represents an integer of 7 to 3, n represents an integer of O-2, but m+
n is preferably an integer of 7 to μ.

In the present invention, a light-sensitive element containing an imagewise exposed light-sensitive silver halide emulsion layer is processed with a processing composition containing a developing agent, a silver halide solvent, and an alkali. An image by silver salt diffusion transfer, which comprises using at least a portion of silver as a transferable silver complex salt, and transferring at least a portion of the complex salt to an image receiving element including an image receiving layer containing a silver precipitant to form an image on the image receiving layer. The forming method is preferably an image forming method using silver salt diffusion transfer, which is characterized in that the image is formed in the presence of the compound represented by the above general formula.

The compound represented by the above general formula may be present in any step of the image forming method. It is usually present either in the photosensitive element containing the light-sensitive silver halide emulsion layer, in the image receiving element containing the silver precipitant-containing image receiving layer, and/or in the processing composition. It is preferably included in the image-receiving element or the processing composition, and particularly preferably in the processing composition.

The amount of the above compound to be used is preferably io-' to /li per treatment composition/00fi. rX10-'~O0!
g is more preferred, and 10-3 to O, coy is most preferred. For sensitive material elements, lO~0. ! j; l/door 2 is preferable, / 0-' ~ 0.2ji/m2 is more preferable
jX/0-'~0,/g/m2 is most preferred.

For the image-receiving element, 10 −/i/ln is preferred, and yoX/ 0-'-0,197 m2 is more preferred/'0
-3 to 0.29/rn2 is most preferred.

Preferred examples of the compounds used in the present invention are listed below.

SO3Na 03Na The compound represented by the general formula can be synthesized by a known method described in the following literature.

The Chemistry of Heterocyclic Con/
(Uns Imidazole and Derivatives, No. 7
Volume (The Chemistry of Heter)
ocyclic compounds 1m1da
Zoleand Derivatives, Vol.
/), Jrlt page, Organic Synthemis, Collective, Volume IV (Org, 5ynth, ■
), j6ri (lrits), Journal of the German Chemical Society (Ber),
? , 41-6! (/P74λ Journal of the American Chemical Society (J, Am, Chcm
.

Soc,), 4Aj, 23ri0 (/9ko3), Tokukai Sho!
0-tri, 03da, same j3-λr, uxt, same! J--
2/,007° Below, the present invention will be explained in more detail.

In the imaging method and film unit of the present invention, the developer may be present in the photosensitive element or processing element. As the developer, a benzene- or naphthalene-based organic compound having a hydrocarbon group and/or an amino group at the para or ortho position, such as hydroquinone, tert-butylhydroquinone, p-aminophenol, etc., is used.

Furthermore, U.S. patent J, t/! , 1L≠O and α,β-enediols as described in US Pat. No. 3,730.7/ are preferably used. Additionally, U.S. Patent 3.21r7,125
Hydroquinylamine developers such as those described in No. 3,293.03 and No. 3,293.03 are particularly preferably used.

The amount of developer used is per 100g of processing solution r) o, 1y-s
It is preferable to contain OP, and /-201 is most preferable.

Further, as a developer, the l-aryl-3-pyrazolidinone compound described in the invention disclosed in Japanese Patent Publication No. Akihiro Tszro may be used in combination with the above developer.

Silver halide solvents may be present in the processing element, the light-sensitive element and/or the image-receiving element. Among these, the processing element is the most preferred. U.S. Patent No. 2,117,27μ; r, r
No. 7.273 and No. 2゜117.271. The cyclic compounds listed in this issue are suitable, among them uracil,
Preferred examples include urazol and bumethyluracil.

Further preferred are alkali metal thiosulfates, especially the sodium or potassium salts, and also as described in U.S. Pat. T, Tatako, same No. J, P74, 44c7, same No. U, 00F,
/47, 4c, 032. ! 3, same @a, ou
t, rtr issue, same day hiro, 04c7. the law of nature! Section number, same number u,
0447. No. 35, No. μ, 107. Disulfonylmethane compounds and US Patent No. 74 and JP-A-7-330.

124, IA No. 2, whistle No. 4c, /O, 221, No. μ, 2//, Jf! No. 2 and No. 2, J//
.

No. 342, a dihydrocypyrimidine compound having a thioether group, and U.S. Patent No. 342, λ! 1, No. 617, No. 47, No. 2!44, and No. Hiroshi.

267.2rls aminothioethers. These can be used alone or in combination; if two or more cyclic imide compounds or dihydro-cypyrimidine compounds with thioether groups are used together, white crystals will precipitate on the surface even if the print is stored for a long time. There is an advantage that this will not happen.

The amount of silver halide solvent added is determined by the processing composition io.

ytr)0. It is preferable to contain /~309, and 0
, ! 17-/all is most preferred.

When the processing liquid used in the present invention is applied by distributing it in a thin layer between a superimposed photosensitive element and an image receiving element, the processing liquid contains a polymeric film former, a thickening agent or a thickening agent. It is preferable that it contains. Hydroxyethylcellulose and sodium carboxymethylcellulose are particularly useful for this purpose and are included in the processing solution at concentrations effective to provide the appropriate viscosity according to known principles of diffusion transfer photography. The processing solution may further contain other auxiliary agents known in the silver salt diffusion transfer process, such as antifoggants, toning agents, stabilizers, and the like. In particular, the inclusion of bovine diethylamino compounds, such as triethanolamine, is described in US Patent No. J, t/f,/l! It is useful for increasing the shelf life of processing solutions.

The processing liquid as described above is preferably stored in a breakable container to serve as a processing element. Any breakable container and material known in the art can be used, and these are described, for example, in US Patent J, 0! t
, μri No. 7, Same J, , OjA, <4 Octopus No., Same J, 1
7J! IrO No. 3゜7!0.207, No.j,
13! , 31/issue, Dohiro, 303,7!0, Dohiro,
JOJ, 7! Detailed information is provided in the / issue, etc.

Image-receiving elements in the present invention include supports carrying an image-receiving layer containing a silver precipitant, such as baryta paper, cellulose triacetate or polyesters. Such receiver elements are preferably prepared by coating the optionally primed support with a coating solution of a suitable cellulose ester, such as cellulose diacetate, in which a silver precipitant is dispersed. The resulting layer of cellulose ester is subjected to alkaline hydrolysis, converting at least a portion of the depth of the cellulose ester to cellulose. In a particularly useful embodiment, a silver precipitant and/or the underlying hydrolysis the cellulose ester in the lower layer that did not undergo
For example, the portion of the cellulose ester layer containing cellulose diacetate that has not been hydrolyzed has the color tone of the silver transfer image,
Contains one or more mercapto compounds suitable for improving stability or other photographic properties. Such mercapto compounds are utilized during imbibition by diffusing from the position where they are initially placed.

A receiving element of this type is described in US Pat. No. 3,407,242.

Examples of suitable silver precipitants include heavy metals such as iron, lead,
Zinc, nickel, cadmium, tin, chromium, copper, cobalt, especially precious metals such as gold, silver, platinum and radium. Other useful silver precipitating agents are sulfides and selenides of heavy metals, especially mercury, steel, aluminum, zinc, cadaverum, cobalt, nickel, metal, lead, antimony,
Mention may be made of the sulphides of bismuth, cerium, magnesium, gold, platinum and noradium, and the selenides of lead, zinc, antimony and nickel. Regarding the function of materials such as silver precipitants in the silver salt diffusion transfer method,
For example, it is described in US Pat. No. 2.771A,667.

Furthermore, it is preferable to provide an intermediate layer between the image-receiving layer and the layer containing a toning agent or stabilizer. Preferred materials for the intermediate layer include gum arabic, polyvinyl alcohol, and polyacrylamide.

Further, it is preferable to provide a peeling layer on the surface of the image-receiving layer in order to prevent the treatment liquid from adhering to the surface of the image-receiving layer during peeling after spreading the treatment liquid. Preferred release layers include gum arabic, hydroxyethyl cellulose, methyl cellulose, polyvinyl alcohol, polyacrylamide, and sodium alginate, as well as US Pat.
72,0λhiro No. 120, P Tata No. and British Patent/, 340. ≦! Examples include those described in No. 3.

The compound used in the present invention is preferably included as a coating composition for an intermediate layer and/or release layer of an image receiving element, or as a saponification liquid composition for alkaline hydrolysis.

In particular embodiments of the invention, image-receiving layers can be incorporated into the photosensitive elements described below. For example, on a polyethylene terephthalate sheet, in order, an image-receiving layer containing a silver precipitant, a light-reflecting layer containing a white pigment such as titanium dioxide, a light-shielding layer containing a light-absorbing substance such as carbon black, and a photosensitive halogenated A preferred example is one provided with a silver emulsion layer. In such an embodiment, the photosensitive silver halide emulsion layer is not peeled off after the diffusion transfer process (also known as
Since the layer behind it is shielded by the light-reflecting layer, the image formed on the image-receiving layer can be observed through the d(IJ ethylene terephthalate sheet).

Furthermore, in the present invention, a photosensitive element obtained by coating a photosensitive silver halide emulsion on a support is preferably used.

In the photosensitive silver halide emulsion used in the present invention, any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide and silver chloride may be used as the silver halide.

Preferred silver halide is silver iodobromide or silver iodochlorobromide containing 10 moles or less of silver iodide. Particularly preferable is 3
Silver iodobromide containing silver iodide from molti to io molti.

The average grain size of silver halide grains in a light-sensitive emulsion (expressed as the grain diameter for spherical or approximately spherical grains, and the ridged grain size for cubic grains, expressed as an average based on the projected area) is particularly important. Although it does not matter, it is preferably 3 μ or less, and more preferably /, J-μ or less, but particularly preferably 0
．． t~ノ, 2μ.

The particle size distribution may be narrow or wide.

The silver halide grains in the light-sensitive emulsion may have equiaxed crystal forms such as cubic or octahedral, or may have irregular crystal forms such as spherical or plate-like, or It may also have a complex shape. It may also consist of a mixture of particles of different crystalline forms.

The interior and surface layers of the silver halide grains may be composed of different phases, or may be composed of a uniform phase. Further, the particles may be particles in which a latent image is mainly formed on the surface, or may be particles in which a latent image is mainly formed inside the particles. Particles in which latent images are mainly formed on the surface are preferred.

The thickness of the photosensitive emulsion layer is from 0.2 to r, oμ, especially o, t-
t, oμ, and the coating amount of silver halide grains is 0. /~
311/7+! 2, preferably 0.2~/#p/m
It is.

The light-sensitive emulsion is prepared by a method commonly used for silver halide photographic emulsions, chemical sensitization and spectral sensitization are performed as necessary, and the emulsion contains antifoggants, stabilizers, hardeners, coating aids, It may contain an antistatic agent and the like. Also, a vehicle such as gelatin is used in the emulsion.

The compound used in the present invention is preferably included in a coating composition for a silver halide emulsion layer and/or a surface protective layer of a photosensitive element.

Exposure to obtain a photographic image may be carried out using a conventional method. i.e. natural light (sunlight), tungsten electric light,
Any of a variety of known light sources can be used, such as a fluorescent lamp, a mercury lamp, a xenon arc lamp, a carbon arc lamp, a medium senon flash lamp, and a cathode ray tube flying spot. The exposure time is 1 from the 171,000 seconds normally used in cameras.
Not only exposure times of 171,000 seconds, but also exposures shorter than 171,000 seconds, such as using a Lifesenon flash lamp or a cathode ray tube.
'~//10 second exposures can be used, or longer exposures than 7 seconds can be used.

If necessary, the spectral composition of the light used for exposure can be adjusted using a color filter. Laser light can also be used for exposure. Alternatively, exposure may be performed using light emitted from a phosphor excited by electron beams, X-rays, r-rays, α-rays, or the like.

Regarding the arrangement and combination method of each element to combine the photosensitive element, image receiving element, and processing element as described above to form a film unit, for example, Neblett (
NeblettesJ, Handbook of 7 Otography and Rhizography (HAND BOO)
K OF PH0TOGRAPHHYAND REPRO
GRAPHY), 7th edition, pages λt-2tj, and particularly preferred embodiments are described in US Pat.
Since it is explained in detail in rO, No. 227, these can be referred to.

(Effects of the present invention) According to the present invention, in the presence of the compound represented by the general formula,
It is possible to obtain an image with a desirable color Kl (Japanese black tone), but if a compound represented by the general formula is used in the processing liquid, the metallic luster of the image may be lost or the maximum density may increase. is obtained.

(Examples) Hereinafter, the present invention will be further explained based on Examples, but the present invention is not limited to these Examples in any way.

Example 1 Silver halide grains were formed by a photosensitive sheet single jet method, physically ripened by a conventional method, desalted, and further chemically ripened to form a silver iodobromide emulsion (according to the iodine content).

3 molchik were obtained. The average diameter of the silver halide grains contained in this emulsion was Q, Tamicron.

This emulsion/Kp contained 0.6 jmol of silver halide. / Kp of this emulsion was collected in a pot and evaporated in a constant temperature pass of a zooc.

Ortho-sensitizing dye J-(-t-chloro-2-
[Coethyl-3-(3-ethyl-2-penzothiazolinylidene)propenyl]-3-benzoxazolio)pronomonesulfonate, panchromatic sensitizing dye (4'-(
-2-((J-Ethylbenzothiazoline-(coylidene)-conethyl-l-propenyl)-3-benzothiazolio)butane-sulfonatone-hydroxy-t
-Methyl-1. J, Ja, 10 d of a 7-weight chronic aqueous solution of 7-thitrazaindene, 10 xl of a 1 wt% aqueous solution of λ-hydroxy-Hiroshi, 6-cyclotriazine sodium salt, and 10 vrl of a 1 wt% aqueous solution of sodium dodecylbenzenesulfonate, riboic acid o, i weight methanol solution i
omt was added and mixed and stirred at 300 ml. This completed emulsion was coated on a polyethylene terephthalate film base containing titanium dioxide which had been primed to a dry film thickness of 3 microns, and dried to obtain a sample. At the same time, polymethyl methacrylate latex (
(average size 3.jμ) was added and applied so that the dry film thickness was 1 micron. The amount of silver coated was 00111/2.

Image-receiving sheet: On a polyethylene laminated paper, cellulose acetate (degree of acetylation 71%)/lp and styrene-maleic anhydride copolymer or acrylic acid-alkyl acrylate copolymer shown in the following table were prepared. acetone λ70w
1 liter and a solution dissolved in methanol 30111! μgo/
It was coated to a thickness of rIL2 and dried. On top of this [,j,J-diphenyl-1,IA-dimercap)-j)l,A)l
-J, jasjeAa-tetrazapentalene (o, or
17 m ) of 10% cellulose acetate acetone solution was applied to give a dry film thickness of 10 p/m 2 . Furthermore, there is a polyacrylic compound on top of this! Add dimethylol urea (!thi) aqueous solution and acetic acid (71%) to thi aqueous solution, respectively.
%, / , 2j% concentration and mix, 21 ml /
m'' coating thickness.Furthermore, on top of this, a solution containing palladium sulfide finely dispersed in an acetone/methanol (r/l) solution of tricellulose acetate was coated.This coating solution contained /, 2! 7-phenyl-!-mercaptoimidazole was contained in a coating amount of x10 = mol/2.The dry thickness was o, rμ.The following alkaline solution was added to this coating. / m2
An image-receiving sheet was prepared by coating the film at a ratio of 1, washing with water, and drying.

The above sulfide/moradium dispersion is made of cellulose acetate! , 3 thiacetone/methanol (R) was prepared by adding 7xio-3 mol of sodium sulfide methanol solution and 7'1.10-3 mol sodium palladium chloride methanol solution and stirring well.

Treatment liquid potassium hydroxide b (111%) 26017 titanium dioxide 3J Kurasil
4Ajl/l-Methyluracil ti-zghydrolifefudiethylcellulose 70I zinc oxide
iogN, N-bismethoxyethylhydroxyluane rag triethanolamine 7. lit Tetrahydropyrimidinethione o, up2.4cm Dimercaptopyrimidine 0.31774-n Propylthiocracil 0.3jp Add the following compounds o, ip to this treatment solution
The processing liquid was spread between the photosensitive sheet and the image-receiving sheet by adding water to a total amount of λq, and then peeled off after 10 seconds had elapsed.

Color tone, maximum density and relative sensitivity at that time (D = o, t)
are shown in Table-7. The minimum concentration showed the values of o and io in both cases.

Table 7 Regarding the metallic luster on the print surface at different peeling times, only the additive-free sample (/-10) of the comparative example showed a slight metallic luster, but none of the other samples showed it.

From Table 1, in the case of compounds used in the present invention (l-/-/
It is clear that -P) has a jet-black color tone and at the same time exhibits a high maximum density, and that the maximum density is higher than when (/-10) is not added.

Example 2 A photosensitive sheet was prepared by adding 0.01 mg1/m2 of the following compound to the silver iodobromide emulsion layer of the photosensitive sheet shown in Example 1, and the processing liquid was a formulation that did not contain the compound of the present invention. The prepared one was used. Then, the same unfolding treatment as in Example 1 was carried out, and the resulting crystals are shown in Table 1.

Table 2 From Table 2, in the case of the compound used in the present invention (λ-/-J
It is clear that -j) provides a jet black tone and at the same time exhibits a high maximum density.

Example 3 The following compound 3 was added to the intermediate layer of the image receiving sheet shown in Example 1.
An image-receiving sheet was prepared by adding 1197 m2, and a processing liquid prepared using a formulation that did not contain the compound of the present invention was used. And then,
The same expansion process as in Example 1 was carried out, and the results are shown in Table 3.

Table 3 From the present invention comparison table 3, in the case of the compounds used in the present invention (3-/~J
It is clear that -j has a jet black tone and a high maximum density, but the comparative samples (3-7 to 3-1) have an undesirable gray tone and a low maximum density.

Claims (1)

[Claims] An imagewise exposed photosensitive silver halide emulsion layer is developed in the presence of a developer, a silver halide solvent and an alkali to transfer at least a portion of the unexposed silver halide of the emulsion layer. A compound represented by the following general formula in an image forming method by silver salt diffusion transfer, which includes forming a silver complex salt into a silver complex salt, and transferring at least a part of the complex salt to an image receiving layer containing a silver precipitant to form an image on the image receiving layer. An image forming method using silver salt diffusion transfer, characterized in that an image is formed in the presence of. General formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, X represents a selenium atom, sulfur atom, or oxygen atom, and R_2 represents a hydrogen atom or an alkyl group. R_1 represents a substituent, Z represents an atomic group necessary to form a carbocycle or a heterocycle, Y represents a carboxyl group or a sulfo group,
M is a hydrogen atom, an alkali metal atom, a quaternary ammonium,
or represents a quaternary phosphonium, m represents an integer of 1 to 3, and n represents an integer of 0 to 2.