JPH022576A - Photoconductive toner - Google Patents

Abstract

PURPOSE:To obtain the photoconductive toner which exhibits photoconductivity with visible light without contg. a carrier generating pigment as a sensitizer by incorporating a photoconductive polymer component having a specific rhodanine deriv. in the main chain and/or side chain of an org. high-molecular photoconductor. CONSTITUTION:This toner contains the photoconductive polymer having the rhodanine deriv. expressed by the formula I in the main chain and/or side chain of the org. high-molecular photoconductor. In the formula I, R denotes the group expressed by the formula II, etc.; in the formula II, R1, R2 denote a hydrogen atom, alkyl group, substd. or unsubstd. aryl group which may be the same as or different from each other; R3 denotes 1-6C lower alkyl group, hydroxyl group. The photoconductive toner obtd. in this way exhibits the excellent photoconductivity in the visible light region even if the sensitizer, charge transfer material, etc., are not incorporated therein. The photoconductive toner is thus obtd. from the fewer constituting components and the uniform dispersion of the respective additives in the toner is possible. The individual characteristics of the toner particle are thus uniformized and the sharp image having no scumming is obtd. at the time of image formation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photoconductive toner, and more particularly to a photoconductive toner in which each particle has uniform photosensitive characteristics and colorability.

(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 photosensitive material to a transfer material, and the electrofox method, which produces a copy by directly developing the photosensitive material, but all of these methods require a development step. The disadvantage is 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 electrostatic latent image, only the photoconductive toner having an electric charge in the unexposed area 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 phototetraconductors, photoconductive polymers such as polyvinyl carbazole (PVC2), and hydrazone, and low-molecular photoconductive compounds are used. Since these photoconductors have poor photoconductivity to visible light, in practical use, sensitizers such as organic dyes and pigments are used together with the photoconductors without reducing photosensitivity and sensitization to visible light. ing. In this way, photoconductive toner is resin fine particles that have many functions such as hue, photoconductivity, and photosensitivity, and in order to exhibit good development characteristics, each additive must be uniformly dispersed in the binder resin. However, it is necessary to make the characteristics of the surface of each toner particle uniform by making it exist on the toner surface.

(Problems to be Solved by the Invention) However, each component such as a colorant, a photoconductor, and a pigment as a sensitizer is finely and uniformly dispersed in the binder resin of each toner particle, and is present on the particle surface. In particular, pigments used as sensitizers tend to exist as aggregates in the binder resin, which causes localized poor dispersion, making it difficult to make the development characteristics of individual toner particles constant. there were.

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.

As a result of extensive research, the present inventors have previously proposed a photoconductive polymer that is characterized in that it generates charges within the polymer and that the generated charges move through charge transport sites within the same polymer.

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 a sensitizer by using the previously proposed photoconductive polymer as a constituent component. There is something to do.

Another object of the present invention is to provide a photoconductive toner comprising as few components as possible and having uniform photosensitive characteristics of each particle.

Still another object of the present invention is to provide a photoconductive color toner with a vivid hue.

(Means for Solving the Problems) The photoconductive polymer of the present invention has a rhodanine derivative of the following structural formula in the main chain and/or side chain of an organic polymer photoconductor, where R1 is the following general formula. R3 and R2 are the same or different and represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aryl group, R3 represents a lower alkyl group having 1 to 6 carbon atoms or a hydroxyl group, and R4 represents a Provided is a photoconductive toner comprising a photoconductive polymer component representing a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group, or a hydroxyl group. .

(Function) The photoconductive 1-ner of the present invention contains a photoconductive polymer component having a rhodanine derivative represented by the following structural formula in the main chain and/or side chain of an organic polymer photoconductor. In the above structural formula, the rhodanine ring part is an electron acceptor, and R at the 5th position of the rhodanine ring is a group represented by the following general formula (representing an acid group), and is considered to be an electron donor. The absorption of is due to the formation of an intramolecular charge transfer complex consisting of this electron acceptor and electron donor.

That is, when the π electrons, which were not intercalated in the electron donor in the ground state, are transferred to the empty orbit of the electron acceptor, they absorb light energy and develop color. Photocarriers are generated by this photoexcitation.

Therefore, the photoconductive polymer component proposed above can be used, for example, in the formula where R is the following general formula (wherein R, , R2 are the same or different and represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aryl group, R3
represents a lower alkyl group having 1 to 6 carbon atoms or a hydroxyl group, and R4
In the case of a group represented by a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group, or water (in the formula, R1 and RZ are as defined in claim 1), orange, and yellow in the case of a group represented by (in the formula, R3 has the same meaning as in claim 1); Suitable examples of the photoconductive polymer that is a raw material compound for the photoconductive toner of the present invention include, but are not limited to, the following.

In the case of the group represented by the formula (in which R4 has the same meaning as in claim 1), it exhibits a blue color and itself has a bright color. Furthermore, the photoconductive component proposed earlier has a hole transport function because it also has an organic polymer photoconductor, and is capable of transporting photocarriers generated by the rhodanine dye through the hole transport site within the same polymer. It is a polymer type photoconductive material.

Therefore, the photoconductive toner of the present invention, in which each particle has uniform photosensitive properties, can be obtained simply by dissolving the previously proposed photoconductive polymer component in the fixing resin to form a toner.

(Preferred response to the invention) lh (Margin below) C11゜ llz +011□ Cll　h”-Temporary Hz-C +V -GCH, -C)I)-7 1+CIh-C11)-7 C=0 C=0 C.B.

C11□ H2 C1!2 -GCII□-C11)-.

C=Q CI+□ C11□ CI+□ -4C11,-C)I)-.

C1!2 CI+! JCII z-CIt)-.

C,0 CI+□ CI+□ C2+I S C2H.

UL, 113 Sushi I+1 C113 C11゜The fixing resin medium for blending the above polymers is as follows:
The resins used in the manufacturing method of this type of toner are used,
Particularly preferred are various mono- or diethylenically unsaturated monomers, especially (a) vinyl aromatic monomers, (
b) Homopolymers and copolymers of acrylic monomers are used.

Examples of the monomer (a) above include styrene, vinyltoluene, α-methylstyrene, α-chlorostyrene, vinylxylene, vinylnaphthalene, etc.
Monomers (b) include methacrylic acid, ethyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 3-aminopropyl acrylate, 3-N,N-
Examples include diethylaminopropyl acrylate and acrylamide.

Other monomers used in combination with these monomers (a) or (b) or alone include butadiene,
In addition to isoprene, chloroprene, etc., maleic anhydride,
Other ethylenically unsaturated carboxylic acids or their esters such as fumaric acid, crotonic acid, itaconic acid, vinyl esters such as vinyl acetate, vinylpyridine, vinylpyrrolidone, vinyl ethers, acrylonitrile, vinyl chloride, vinylidene chloride, etc. can be mentioned. The molecular weight of these resins is 3,000 to 300,000°, especially 5
,000 to 200,000.

By using 50 to 200 parts of the previously proposed photoconductive polymer per fixing resin medium, the photoconductive toner of the present invention has good photosensitivity, photoconductivity, and fixability.

In addition, in producing the photoconductive polymer proposed earlier, for example, a monomer obtained by introducing a reactive substituent into the monomer that will serve as the fixing resin medium and reacting it with a rhodanine derivative, and an organic A direct fixing resin medium can also be included by copolymerizing the monomers that make up the polymeric photoconductor.

Further, when the toner is a heat fixable toner, the softening point of the polymer is 50 to 200° C. Preferably, the softening point is 70° C.
~170°C is preferred.

In addition, examples of colorants that color the photoconductive toner black or other hues include carbon black, lamp black (C, I, No., 77266), 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 (C01, No. 470)
05), Permanent Orange GTR (C, 1, No.
12305), plasticine orange (C, 1, No, 2
1160), Watch Young Red (C, 1, No.

15868), permanent red (C, 1, No, 1
2310 etc.), brilliant carmine 3B (C, 1, N
o, 16105), brilliant carmine 6B (C,
1, No. 15850), DuPont Oil Red (C
, 1, No. 26105), Pyrazolone Red (C.

1, No. 21120), Lysol Red (C, lNo.
, 15630), Rhodamine B Lake (C,lNo,
45170), Lake Red C (C, 1, No. 45
435), Aniline Blue (C, 1, No.

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

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

1vent Blue 35, C, 1Solvent
Green 15, C, 1, S.

Examples include oil-soluble dyes such as 1vent Ilrown 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.

In addition, 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), oil black (C01, No. 26150) as other additives. ), oil-soluble dyes such as Spiron black, naphthenic acid, salicylic acid, octylic acid, fatty acids mentioned below, resin acids such as manganese, iron, cobalt, lead, zinc, cerium, calcium, metal soaps that are metal salts of nickel, etc. Alternatively, metal-containing azo dyes, pyrimidine compounds, alkyl salicylic acid metal chelates, etc. may be contained in an amount of 0.01 to 5% by weight based on the binder resin.

In addition, in order to prevent the toner from adhering to the fixing roller, the toner may contain an anti-offset 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 in a weight percent.

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.

In addition, the method for producing the photoconductive toner of the present invention includes a photoconductive polymer having a rhodanine derivative in the main chain and/or side chain of an organic polymer photoconductor, and a colorant or other additives as necessary. After mixing and kneading the ingredients, the mixture is pulverized. 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 fabrush and rubbed against the conductive substrate with this, thereby forming a toner layer on the substrate. In this case, if a bias voltage is applied between the conductive substrate and the sleeve or fur brush, the toner layer can be formed more easily.

The toner layer formed on the conductive substrate has already been charged by the toner itself, but if necessary, it may be forcibly charged using a corotron or the like. The thickness of the toner layer is such that toner particles are formed in one layer or several layers, and the coating amount is generally 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 exposure amount varies greatly depending on the sensitivity of the photoconductive toner, but is generally between 50 and 2001 ux-se.
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 coercive heat roller in a heater or an oven heater.

The fixing temperature is generally in the range of 160 to 200°C.

(Example) Hereinafter, the present invention will be explained in more detail based on Examples.

Example 1 [Synthesis of monomer with rhodanine derivative] 3-acrylamide-5-(P-diethylaminobenzylidene)
Synthesis of rhodanine 10.4g of methacrylic acid chloride and 3-amino-5
-(P-diethylaminobenzylidene)rhodanine 31
g was dissolved in 200 mf of pyridine, stirred and reacted at 80°C for 4 hours, and the product was recrystallized from acetone to obtain the above compound.

[Synthesis of photoconductive polymer] 3-acrylamide-5-(P-diethylaminobenzylidene) rhodanine and (2-N-carbazolylethyl)
Copolymerization of acrylate 3.7 g of 3-acrylamide-5-(P-diethylaminobenzylidene) rhodanine and 2.5 g of (2-N-carbazolylethyl)acrylate, 0.05 g of azobisisobutyronitrile as a polymerization initiator, Add 20 ml of methylene chloride as a solvent and mix the above mixture with 50 ml of methylene chloride. ! The mixture was placed in a polymerization tube and degassed several times to create a sufficient vacuum state using the sealing tube method to create an ampoule.

After immersing this in a 60°C constant temperature bath for 30 hours to react, methanol was added to stop the reaction, and reprecipitation was performed with methylene chloride and methanol. A polymer was obtained (molecular weight was 15,200 in terms of polystyrene, copolymerization ratio was rhodanine:
carbazole-3nia).

[Manufacture of toner]

A solution consisting of 100 parts by weight of a styrene-acrylic copolymer as a fixing resin, 90 parts by weight of the photoconductive polymer obtained above, 2,500 parts by weight of toluene and 500 parts by weight of THF as a solvent was thoroughly mixed and dispersed, and a spray-drying method was applied. A photoconductive toner having a center particle of 11 μm was obtained. This toner is photosensitive to blue light around 480 nm.

Next, the toner obtained in step 1 and an electrophotographic carrier (ferrite carrier, average particle size: 80 μm) were mixed and negatively charged (toner concentration: 8%). When this toner was deposited on an aluminum substrate and an image was formed using blue light, a bright orange image was obtained with no missing characters and no background fog.

(Example 2) 100 parts by weight of the photoconductive polymer obtained in Example 1, 100 parts by weight of styrene-acrylic copolymer, 10 parts by weight of spironoblack, 2500 parts by weight of toluene as a solvent, TH
A solution consisting of 50 parts by weight of F was thoroughly mixed, and a photoconductive toner having a center particle size of 11 μm was obtained by spray drying.

The toner obtained above and an electrophotographic carrier (ferrite carrier, average particle size 80 μm) were mixed and negatively charged. This toner was 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 exhibits excellent photoconductivity in the visible light region even without containing a sensitizer or a charge transport material. For the sake of closure,
A photoconductive toner can be obtained with a small amount of constituent materials, and the additives in the toner can be dispersed in a uniform manner, resulting in uniform properties of the individual toner particles. Therefore, a clear image without background fog can be obtained during image formation.

Further, since the binder resin is a photoconductor and exhibits a bright color, a photoconductive toner with excellent translucency can be obtained without containing a colorant.

Claims (1)

[Claims] In the main chain and/or side chain of the organic polymer photoconductor, there is a rhodanine derivative with the following structural formula ▲ Numerical formula, chemical formula, table, etc. ▼ In the formula, R is the following general formula ▲ Numerical formula, chemical formula , tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. Carbon number 1~
6 represents a lower alkyl group or hydroxyl group, and R_4 represents a hydrogen atom, a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group, or a hydroxyl group. A photoconductive toner characterized by: