JPH01161362A - Photoconductive toner - Google Patents

Abstract

PURPOSE:To obtain a photoconductive toner uniform in photosensitivity of each toner particle by dispersing a carrier transfer material into a resin made of a chain polymer having specified derivatives on its side chains or mutually dissolving with said polymer. CONSTITUTION:The photoconductive toner is obtained by dispersing or mutually dissolving the carrier transfer material into the resin made of the chain polymer having on its side chains the rhodanine derivatives represented by formula I in which R1 is lower alkyl, optionally substituted aryl, H, or OH. Said toner has superior photoconductivity in the visible light region without containing a carrier generating material, thus permitting each toner particle to have uniform characteristics and to form a sharp image free from background fog. The binder resin itself has photoconductivity, and a clear blue color, and a photoconductive blue toner superior in light transmittance is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an image forming method, and more particularly to a photoconductive toner having uniform photosensitivity of each particle.

(Prior art) A typical image forming method applying electrophotographic technology is to visualize an electrostatic latent image formed on a photoreceptor with toner to form a toner image, and then print this toner image on plain paper. Examples include the xerography method, which obtains a copy by transferring the image to a transfer material such as, and the electrofox method, which directly develops the photosensitive material to produce a copy, but all of these methods require a development step. , has the disadvantage that the equipment for its implementation is complex and expensive.

To solve this problem, a photoconductive toner is uniformly deposited on a conductive substrate to form a toner layer, and this toner layer is charged and imagewise exposed to charge the photoconductive toner in the exposed area. An image forming method is known in which, after forming an electrostatic latent image by eliminating or weakening the photoconductive toner, only the charged photoconductive toner in the unexposed areas is transferred to a transfer material. The photoconductive toner used in this image forming method is generally resin fine particles in which a photoconductive substance is dispersed together with a coloring agent in a binder resin. Organic photoconductors such as polyvinylcarbazole (PVC2), photoconductive polymers such as hydrazone, and organic photoconductive compounds such as low-molecular photoconductive compounds are used.These photoconductors emit visible light. In practical use, sensitizers such as organic dyes and pigments that show photosensitivity and sensitization to visible light are used together with photoconductors.In this way, photoconductive toners have poor photoconductivity. These fine resin particles have many functions such as hue, photoconductivity, and photosensitivity.In order to exhibit good development characteristics, each additive must be uniformly dispersed in the binder resin and present on the toner surface. It is necessary to make the characteristics of the toner particles uniform.

(Problems to be Solved by the Invention) However, each component of the colorant, photoconductor, and pigment as a sensitizer is finely and uniformly dispersed in the binder resin on each side of the toner particles, and is present on the particle surface. It is difficult to make
In particular, pigments as aggravating agents tend to exist as aggregates in the binder resin, causing poor dispersion, making it difficult to make the development characteristics of each toner particle constant. In the case of photoconductive color toners, the photoconductor and sensitizer also have the disadvantage that the toner has a poor hue, resulting in images that lack vividness.

Therefore, an object of the present invention is to provide a photoconductive toner that exhibits photoconductivity in visible light without containing a carrier-generating pigment as an aggravating agent. Another object of the present invention is to provide a photoconductive toner comprising as few components as possible and exhibiting uniform properties. Furthermore, another object of the present invention is to
To provide a photoconductive color toner with vivid hue.

(hereinafter referred to as Rinpaku) (Means for solving the problem) (1) A rhodanine derivative with the following structural formula in the side chain (in the formula R +
represents a lower alkyl group, a substituted or unsubstituted ester group, a hydrogen atom, or a hydroxyl group). By obtaining, the above problems are solved and the purpose is achieved.

The present invention will be described in detail below. The polymer of the present invention that generates carriers with visible light has a rhodanine ring in its molecular chain and a quinoline group introduced into the 5-position of the rhodanine ring via an ethanediilidene group. In the above polymer, the rhodanine ring part is considered to be an electron acceptor, and the quinoline part is considered to be an electron donor, and forms an intramolecular charge transfer type complex when exposed to visible light.

That is, when the π electrons delocalized in the electron donor in the ground state are transferred to the empty orbit of the electron acceptor through the group r=C=CH-CH=J, light energy is absorbed and color is generated.

Photocarriers are generated by this photoexcitation.

Further, the polymer according to the present invention has particularly excellent film-forming properties and light transmittance by itself.

Therefore, this charge-generating material can be used, for example, by combining hole-transporting materials such as hydrazone derivatives, triphenylamine derivatives, and pyrazoline derivatives to transfer photocarriers generated in the polymer through hole-transporting materials that are made compatibilized in the polymer. It becomes possible to move.

Since the polymer having this rhodanine derivative in its side chain is itself translucent and has a blue hue, the photoconductive material is dispersed in a carrier-generating pigment as an enhancer in the binder resin. There is no need for this, and by simply forming a toner by using the above polymer as a binder resin and adding a hole transporting material, a toner without excellent photoconductivity on the particle surface can be obtained.

(Preferred Embodiment of the Invention) It can be obtained by simply bonding to a polymer compound having a rhodanine ring and a heromethyl group in the side chain used in the present invention by a nucleophilic substitution reaction.

Rhodanine derivatives, which are components of such polymers, are as follows: ). The alkyl group for R1 is methyl, ethyl, propyl, isopropyl, butyl,
Examples include lower alkyl groups such as isobutyl, tert-butyl, pentyl, and hexyl groups; examples of aryl groups that may have substituents include phenyl, naphthyl, tyndryl, phenanthryl, and fluorenyl; examples of substituents include , a lower alkyl group having 1 to 4 carbon atoms, methoxy,
Examples include alkoxy groups such as ethoxy and propoxy, amino groups, alkylamino groups such as dimethylamino, diethylamino and dipropylamino groups, and halogen atoms.

Specifically, S As shown in the above specific example, the reactive substituent B is -C
Examples include OOII-CHzCI-OH-COCI-NHz.

These rhodanine derivatives can be synthesized by various methods, such as the following reaction formula.

(Hereinafter, blank space) (In the formula, B and R1 are the same as above.) That is, the rhodanine derivative is a 3-substituted rhodanine and a 4-substituted rhodanine.
-β-A7toanilide It can be obtained by reacting vinylquinoline alkyl iodide in alcohol.

Examples of the polymer having a reactive substituent to which the above-mentioned rhodanine derivative is bound include the following repeating units 10; 8! -CH)- (CH).

Polyallylamine represented by Ht (in the formula, m represents an integer of O to 3), the following repeating unit → CH, -CH← z (in the formula, R2 is -CHzC1, -NHz, -5o□C1
, -COOH) is a styrenic polymer represented by the following repeating unit COOHC Co., Ltd.

Acrylic or methacrylic polymers represented by H (wherein R1 is a hydrogen atom or a methyl group, m represents an integer of O to 3), copolymers of these repeating units, or polymers having the above repeating units It may also be a copolymer consisting of a component and a polymer component other than the above-mentioned repeating unit. Monomers constituting such polymer components include styrene monomers, acrylic or methacrylic monomers, carboxylic acids or alkyl esters having unsaturated double bonds, oleic monomers,
Examples include vinyl chloride and vinyl acetate.

Furthermore, polymers having phenyl rings in the main chain or side chains such as the styrene polymers and polycarbonate resins are reacted with CHs COCHz CI, and polymers having 10H2C1 as a reactive substituent are also used. can.

Reactions between these polymers and rhodanine derivatives are achieved, for example, by the following reaction.

<1) And the rhodanine derivative is 20 to 50 per whole polymer.
Particularly preferred are polymers having a weight percent of 30 to 40 weight percent.

If the amount of the rhodanine derivative is more than the above range, the crushability will be poor and it will be difficult to form a toner. If it is less than the above range, sufficient photoconductivity will not be obtained.

The above polymer has a weight average molecular weight of 30,000 to 20
0°OOOO, particularly preferably 50.000 to 150.000.

Further, when the toner is a heat fixable toner, the softening point of the polymer is 50 to 200°C, preferably 70 to 200°C.
One having a temperature of 170°C is preferred.

It is also possible to use a blend of known binder resins for toners that have good compatibility with the above polymers as long as the photoconductivity is not impaired.

As the charge transport material added to the polymer, known electron transport materials and hole transport materials can be used. Specifically, electron-accepting substances having an electron-accepting group such as a nitro group, a nitroso group, or a cyano group, such as tetracyanoethylene, fluorenone-based compounds such as 2.4°7-trinitro-9-fluorenone, dinitroanthracene, 2
．． 4. Nitro compounds such as 8-trinidrothioxanthone; electron donating substances such as N,N-diethylamide
Novobenzaldehyde N,N-diphenylhydrazone, N-methyl-3-carbazolaldehyde N,N
- Hydrazone compounds such as diphenylhydrazone, 2.
5-di(4-N,N-dimethylaminophenyl)-1,
3,4-oxadiazole, 2,5-di(4-N,N-
oxadiazole compounds such as (diethylaminophenyl)-1,3,4-oxadiazole, schel compounds such as 9-(4-jethylamianostyryl)anthracene, carbazole compounds such as N-ethylcarbazole,
1-phenyl-3-3(4-dimethylaminophenyl)
Pyrazoline, 1-phenyl-3-(4-dimethylaminostyryl)-5-(4-dimethylaminophenyl)pyrazoline, l-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminophenyl)pyrazoline, etc. Pyrazoline compound, 2-(4-diethylaminophenyl)-4-(4-dimethylaminophenyl)-
Oxacin compounds such as 5-(2-chlorophenyl)oxazole, isoxazole compounds, thiazole compounds such as 2-(4-diethylaminostyryl)-6-dinithylaminohenzothiazole, triphenylamine, 4.4-bis (Amine derivatives such as N-(3-methylphenyl)-N-phenylaminocobiphenyl, stilbene compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, indole compounds,
Nitrogen-containing cyclic compounds such as triazole compounds, fused polycyclic compounds such as anthracene, pyrene, phenanthrene,
Examples include poly-N-vinylcarbazole, polypropylene, polyvinylanthracene, ethi-Atcarbazole-formaldehyde resin, and the like. One or more of the above charge transport substances are used, and are added to the polymer in consideration of toner fixability and cohesiveness, and are 20 to 50 parts by weight, preferably 30 to 40 parts by weight, per 100 parts by weight of the polymer. part is used.

In addition, examples of colorants that color the photoconductive toner black or other hues include carbon black, lamp black (C, 1, No. 77266), and chrome yellow.
(C, 1, No, 14090), Hansa Yellow (C,
1, No. 11660.11680, etc.), benzidine yellow (C, 1, No.

21100 etc.), Suren Yellow G (C, 1, No. 7)
0600), Quinoline Yellow (C, 1, No, 470
05), Permanent Orange GTR (C, T, No,
12305), plasticine orange (C, 1, No, 2
1160), Watch Young Red (C, 1, No.

15868), permanent red (C, I, No.
, 12310 etc.), brilliant carmine 3B (C,
1, No. 16105), Brilliant Carmine 6B (
C, 1, No. 15850), DuPont Oil Red (
C, 1, No. 26105), Pyrazolone Red (C.

lNo, 21120), Lysole Red (C, 1, No.
, 15630), Rhodamine B Lake (C, 1, No.
, 45170), Lake Red C (C, 1, No. 4
5435), Aniline Blue (C, 1, No.

77103), Calco Oil Blue (C, 1, No, a
zoec Blue3), methylene blue chloride (
C,I, No. 52015), phthalocyanine blue (C,1,No., 74260), malachide green oxalate (C,I No., 42000), etc., or nigrosine dye, Subiron black, etc., and C,1,S.

1vent Yellow 60, C, 1,5olv
ent'Red 27, C, 1, S.

1vent Blue 35, C, 1,5olve
nt Green 15, C, 1, S.

Examples include oil-soluble dyes such as 1vent Brown 5, and oil-soluble dyes are particularly preferred from the viewpoint of photoconductivity and colorability.

These colorants may be used singly or in combination of two or more, for example, 1 to 30 parts by weight, preferably 2 to 20 parts by weight, per 100 parts by weight of the binder resin.

Note that in order to control the charge of the toner as necessary, the above toner may contain a charge control agent such as nigrosine dye (C, 1, No. 50415B) and oil black (C, 1, No. 50415B) as other additives. , 26150), oil-soluble dyes such as Spiron black, and metal salts of naphthenic acid, salicylic acid, octylic acid, fatty acids mentioned below, resin acids such as manganese, iron, cobalt, lead, zinc, cerium, calcium, and 2.7 Kel. metal soaps, metal-containing azo dyes, pyrimidine compounds, alkyl salicylic acid metal chelates, etc.
The content may be 0.01 to 5% by weight based on the binder resin.

In order to prevent the toner from adhering to the fixing roller, the toner may contain an offset preventing agent, such as various waxes such as low molecular weight polypropylene, low molecular weight polyethylene, and paraffin wax, and olefin monomers having 4 or more carbon atoms. 0.5 to 15% of low molecular weight olefin polymer, fatty acid amide, silicone oil, etc. per toner.
It may be contained by weight%.

In addition, in order to improve the fluidity of the toner as necessary,
The toner may be surface-treated with an external additive such as a silane coupling agent, silicone, or a fluorine compound.

Further, the method for producing the photo-R conductive toner of the present invention includes mixing a chain polymer having a rhodanine derivative in its side chain, a charge transporting material, and, if necessary, a coloring agent and other additives.
After kneading, it is finely ground. Alternatively, a toner having a particle size of 5 to 50 μm is produced by mixing and dispersing the mixture in a suitable solvent and spray-drying the resulting solution.

For image formation using the toner of the present invention, in addition to metal plates such as aluminum plates and tin plates and drums thereof, transparent conductive substrates such as Nesa glass are used. Any means known per se can be used to form the toner phase on the substrate, for example by mixing the toner composition described above with a magnetic carrier to form a two-component composition, which The magnetic brush is supplied onto a sleeve having a magnet therein, and the magnetic brush rubs against the conductive substrate to form a toner layer on the substrate. Further, the charged toner is supported on a Noah brush, and the conductive substrate is rubbed with the brush, thereby forming a toner layer on the substrate. In this case, when a bias voltage is applied between the conductive substrate and the brush on the sleeve or fur, the toner layer is more easily formed.

The toner layer formed on the conductive substrate has already been charged, but if necessary, it may be forcibly charged using a corotron or the like. The coating amount is 8 to 50 g/m'' in terms of weight per unit area.

Image exposure includes uniform exposure of the entire surface using a flash lamp,
This can be performed by slit exposure using a halogen lamp or the like. The amount of exposure varies greatly depending on the sensitivity of the photoconductive toner, but it ranges from 50 to 2001 ux-se for -i.
The range c is the mortgage.

As the transfer means, corona discharge transfer or roller electrode transfer, which are known per se, can be used, and the fixing operation can be performed using a per se known pressure and heat port with a built-in heater or an oven heater.

Generally, a suitable fixing temperature is in the range of 160 to 200°C.

(Example 1) [Ni! in polystyrene side chain! 1-5- (4-(1-
Synthesis of polymer supporting rhodanine] 19.1 g of 3-carboxymethylrhodanine and 4-β
-A7toanilide vinylquinoline ethiodide 46.6
After refluxing 12.2 g of triethylamine in ethanol for 30 minutes, the product was recrystallized from pyridine to synthesize 3-carboxy-5-(4-(*thylquinoline)dimethine)rhodanine.

(Yield 53%) After dissolving 15.2 g of chloromethylated polystyrene, 37.2 g of the above-obtained 3-carboxymethyl-5-(4-(1-ethylquinoline)dimethine]rhodanine, and 12 ml of triethylamine in 100 ml of DMF, React at 100°C.

After 2 hours, the reaction solution was added to a mixed solution of water and methanol (1:1) with stirring to cause precipitation. Next, water/methanol (
After washing with a 1:1) mixed solution, reprecipitation was performed with THF/hexane and drying under reduced pressure. A polymer in which N-substituted a-5-(P-diethylaminobenzylidene) rhodanine was supported on the polystyrene side chain obtained by the above method was obtained.

As a result of elemental analysis, 3-carboxymethyl-5- to chloromethylstyrene units in chloromethylated polystyrene
The binding rate of [4-(1-ethylquinolinedimethine]rhodanine) was almost 100%.

A solution consisting of 100 parts by weight of the above-obtained polymer having rhodanine units, 40 parts by weight of 4-diethylaminobenzaldehyde 1,2-diphenylhydrazone as a charge transport material, 2500 parts by weight of toluene and 500 parts by weight of THF as a solvent were thoroughly mixed. A photoconductive toner having a center particle of 10 μm was obtained by dispersing and spray drying. This toner is a toner that has a light intensity of red light around 620 nm. Next, the toner obtained above was mixed with an electrophotographic carrier (ferrite carrier, average particle size: 80 μm) and negatively charged (toner concentration: 8%). When this toner was deposited on an aluminum substrate and an image was formed using red light, a bright blue image was obtained with no missing characters and no background fog.

(Example 2) 3-Amino-5-(4-(1-ethylquinoline) Dimethine]rhodanine was synthesized. (yield 51%) 10.5g of polymethacrylic acid chloride and 34.2g of 3-amino-5-(4-(1-ethylquinoline)dimethine)rhodanine obtained above were mixed in 100ml of pyridine. 8
The reaction was carried out at 0°C for 3 hours.

Then, precipitation and washing were repeated and dried under reduced pressure to obtain a polymer in which N-substituted-5-(4-(l-ethylquinoline)dimethine)rhodanine was supported on the side chain of polymethacrylic acid.

A solution consisting of 100 parts by weight of the above-obtained polymer having rhodanine units, 35 parts by weight of 4-diethylaminobenzaldehyde 1,2-diphenylhydrazone as a charge transport material, 2500 parts by weight of toluene and 500 parts by weight of THF as a solvent were thoroughly mixed. A photoconductive toner having a center particle of 11 μm was obtained by dispersing and spray drying.

(Example 3) The same operation as in Example 1 was performed except that 40 parts by weight of 4゜4゛-bis[N-phenyl-N-(3-methylphenyl)aminocodiphenyl was used as the charge transport material. A photoconductive toner with a particle size of about 10 μm was obtained.

When an image was formed using this photoconductive toner in the same manner as in Example 1, a clear blue image was obtained.

(Example 4) 4-diethylaminobenzaldehyde 1,2-diphenylhydrazone 4 was added as a charge transport material to 100 parts by weight of the polymer having the rhodanine derivative in the side chain obtained in Example 1.
A solution consisting of 0 parts by weight, 10 parts by weight of spironoblack, 2500 parts by weight of toluene as a solvent, and 50 parts by weight of THF was thoroughly mixed, and the mixture was spray-dried to a median particle size of 11 parts by weight.
A .mu.m photoconductive toner was obtained.

The above-obtained toner and electrophotographic carrier (ferrite carrier, average particle size: 80 μm) were deposited on an aluminum substrate, and imagewise exposed to white light to obtain a black toner image corresponding to the original image. The obtained image was clear with no background fog.

(Effects of the Invention) As is clear from the above examples, the photoconductive toner obtained by the present invention does not contain a carrier-generating substance and exhibits excellent photoconductivity in the visible light region. The grain characteristics are uniform and clear images without background fog can be obtained during image formation. Further, a photoconductive blue toner in which the binder resin is a photoconductor, exhibits a vivid blue color, and has excellent translucency can be obtained.

Claims (2)

[Claims] (1) A rhodanine derivative with the following structural formula in the side chain ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 represents a lower alkyl group, a substituted or unsubstituted aryl group, a hydrogen atom, or a hydroxyl group). A photoconductive toner made by dispersing or dissolving a charge transporting material in a polymer consisting of a macromolecule. (2) The above rhodanine derivative is 2 per whole chain polymer.
The photoconductive toner according to claim 1, containing 0 to 50% by weight.