JPH0353262A - Developer - Google Patents

Abstract

PURPOSE:To prevent the sticking of a toner to the window of a sensor and to control the concn. of the toner in a developer to a correct value by using the developer contg. a specific nonmagnetic toner and a resin coated carrier. CONSTITUTION:A screw 7 which transports the fresh toner and the toner and carrier recovered from the surface of a sleeve 2b to a transporting pipe 31 while uniformly mixing the toners and the carrier is provided in the lower part of a developer container 2. The sensor window for a toner concn. detector 20 is provided in the transporting pipe 31. The carrier of the developer is pro vided with the coating layer consisting of a resin on the surface of magnetic material particles. The toner is constituted of the binder resin as well as a perylene pigment, and 'C.I. Pigment Yellow 81R'. The rise of the electrostatic charge of the toner is, therefore, fast and the replenished toner is immediately provided with the correct electrostatic charge quantity by the agitating and mixing with the carrier. The sticking of the toner to the sensor window is obviated in this way and the stable control of the concn of the toner in the developer to the correct value is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is applicable to a developing device having a photo-sensing toner density control device in electrophotographic copying devices and electrostatic recording devices used for various purposes. This invention relates to color developers.

[Prior Art] In a developing device using a two-component developer consisting of toner and carrier, the ratio of toner to carrier is an extremely important factor in terms of the developing effect. That is, when the toner density is below the appropriate level, the image density becomes low, and when the toner density is above the appropriate level, the toner cannot be sufficiently charged, causing problems such as fogging. Therefore, in order to obtain a good image, it is necessary to accurately detect the developer concentration and control the toner concentration to an appropriate value.

Regarding toner density control (ATR) methods, various proposals have been made in the past, and one proposed in particular in Japanese Patent Publication No. 3G-17245, etc. detects the color of the developer and controls the amount of toner replenishment. The means is a stable detection means that is not easily affected by changes in physical properties such as high density of the developer due to environmental changes or durability.

As a toner concentration detection section for the above photodetection ATR method, for example, the one shown in FIG. 5 is generally known. This is a lamp (light source) that irradiates light onto the developer in the transport path A from a sensor window 13 made of a transparent material provided at a predetermined location on the transport path A of the developer consisting of toner and carrier.
10, a first sensor 11 that receives the reflected light that has been mixed with the developer, and a second sensor 12 that directly receives the light from the lamp 10.

In this toner concentration detection method, the first sensor 11
receives the reflected light reflected by the developer and outputs the voltage,
The second sensor 12 directly receives the light from the lamp lO and detects the toner concentration from the difference between the output voltage and the received light. In this photodetection ATR method, since the developer comes into contact with the toner concentration detection device, there is a problem that the detection device is scratched by the carrier. Therefore, the carrier is coated with resin on the surface that does not damage the sensor window surface. carriers are preferred.

However, carriers whose surfaces are coated with resin have high electrical resistance, and when copying is continued in a low-temperature environment, the toner has an excessive charge and adheres firmly to the carrier surface.

Even if toner is newly replenished into the developer in this state, the replenished toner will not have a chance to come into contact with the carrier due to the toner adhering to the carrier, and will not be able to be sufficiently charged. , toner with a small amount of charge is
The developer adheres to the surface of the sensor window, which is charged to the opposite polarity to the toner.

When toner adheres to the sensor window, the ATR device malfunctions and controls the toner concentration of the developer below an appropriate value, resulting in problems such as a decrease in image density and fogging.

On the other hand, in current copying machines, the importance of copying in chromatic colors other than black is increasing.

It has been proposed to use perylene pigments as a coloring agent for chromatic toners, especially red toners (Japanese Patent Laid-Open No. 1986-59
-197049).

However, developers that combine toners containing only these pigments and resin-coated carriers have low ? When continuous copying is performed in a W environment, toner tends to adhere to the surface of the ATR sensor window, making it difficult to control the toner concentration of the developer to an appropriate value.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned conventional problems and to provide a developer suitable for a developing device having a photodetection automatic toner density control device.

[Means and Effects for Solving the Problems] As a result of intensive research, the present inventors have discovered that at least perylene pigments and C.I. I. Pigment Y
By using a developer containing a non-magnetic toner containing yellow, 81 and a binder resin, and a resin-coated carrier, it is possible to prevent the toner from adhering to the sensor window and prevent the ART device from malfunctioning. I found it.

The present invention will be explained in detail below.

The developer carrier used in the present invention is constructed by providing a coating layer made of resin on the surface of magnetic particles.

As the material of the carrier core material used in the present invention, for example, surface oxidized or unoxidized metals such as iron, nickel, cobalt, manganese, chromium, rare earths, and their alloys or oxides can be used, but preferably Metal oxides, more preferably ferrite particles can be used.

In addition, the surface of these ferrite particles can be treated with zinc oxide, manganese oxide, nickel oxide, etc., which have lower hardness than ferrite.
Ferrite particles coated with a metal oxide such as cerium oxide or tungsten oxide are more preferable because they are less likely to damage the ATR sensor window.

The average particle diameter of the carrier core material is generally preferably from 30 to 90 pm, more preferably from 35 to 70 m. If the average particle diameter is less than 30 μm, the carrier is likely to be developed (transferred together with the toner) onto the latent image carrier, and the latent image carrier and cleaning blade are likely to be damaged. On the other hand, if the average diameter of the carrier is larger than 70←m, the toner retaining ability of the carrier is reduced, and unevenness of the solid image, toner scattering, fogging, etc. are likely to occur. Also, A
The TR sensor window surface will be easily damaged.

Further, such a carrier core material may be a mixture of two or more types of magnetic particles.

As the resin used for coating the carrier of the present invention, known resins can be used, but fluororesins and styrene resins are particularly preferred.

Examples of fluororesins include polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, halofluorobolymers such as polytrifluorochloroethylene, polytetrafluoroethylene, polyverfluoropropylene, vinylidene fluoride, and acrylics. Copolymers with monomers, copolymers of vinylidene fluoride and trifluorochloroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene, copolymers of vinyl fluoride and vinylidene fluoride, Copolymers of vinylidene fluoride and tetrafluoroethylene, copolymers of vinylidene fluoride and hexafluoropropylene, turbolimers of tetrafluoroethylene and vinylidene fluoride and non-fluorinated monomers, etc. Preferably used.

In order to impart sufficient chargeability to the toner, these fluorine polymers are preferably used in combination with a styrene-acrylic polymer as the other polymer.

Also, the ratio of fluorine polymer to other polymers is 20:
A ratio of 80 to 80:20% by weight is preferred. More preferably, it is 40:60 to 60:40 wt%.

The weight average molecular weight of the fluorine polymer is 50. 000
~400,000 is preferred. More preferably 100
,000 to 250,000.

On the other hand, as the styrene resin, styrene monomers such as styrene derivatives such as styrene α-methylstyrene, p-methylstyrene, pt-butylstyrene, and p-chlorostyrene are used.

Various other copolymerization components can be used, and acrylic monomers are particularly preferred. For example, methyl methacrylate, ethyl methacrylate, probyl methacrylate, butyl methacrylate, bentyl methacrylate, hexyl methacrylate, hebutyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate. , glycidyl methacrylate, methoxyethyl methacrylate, broboxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydibrobylene glycol methacrylate, Phenoxyethyl methacrylate, phenoxydiethylene gnocol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, cyclopentenyl methacrylate, dicyclobentenyloxy methacrylate Ethyl, N-vinyl-2-pyrrolidone methacrylate, methacrylic nitrile, methacrylamide, N-methylolmethacrylamide, ethylmorpholine methacrylate, diacetone acrylamide, methyl acrylate,
Ethyl acrylate, probyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, hebutyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, glycidyl acrylate, acrylic Methoxyethyl acrylate, broboxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene gnocol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydibrobylene glycol acrylate, phenoxyethyl acrylate , phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclobentenyl acrylate, dicyclopentenyloxyethyl acrylate, N- acrylate
Vinyl monomers having one vinyl group in each molecule, such as vinyl-2-pyrrolidone, glycidyl acrylate, acrylonitrile, acrylamide, N-methylolacrylamide, diacetone acrylamide, ethylmorpholine acrylate, and vinylbilidine, divinylbenzene, Reaction products of glycol and methacrylic acid or acunolic acid, such as ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1.
4-butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neobentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tribro Bilene glycol dimethacrylate, hydroxybivalic acid neobentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate,
Tris(methacryloyloxyethyl)in cyanurate ethylene glycol diacrylate, 1.3-butylene glycol diacrylate, 1.4-butanediol diacrylate, 1.5-pentanediol diacnolate, 1.6-hexanediol diacrylate , neobentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene diacrylate, neopentyl glycol diacrylate hydroxypivalate, trimethylolethane triacrylate, trimethylolpropane triacrylate, penta erythrittetraacrylate,
Tris acryloxyethyl phosphate, tris (methacryloyloxyethyl) isocyanurate, half ester of glycidyl methacrylate and methacrylic acid or acrylic acid, half ester of bisphenol type epoxy resin and methacrylic acid or acrylic acid,
Acrylic monomers having two or more vinyl groups in one molecule, such as half esters of glycidyl acrylate and methacrylic acid or acrylic acid, 2-hydroxyethyl acrylate, 2-hydroxybrobyl acrylate, and hydroxybutyl acrylate. , 2-hydroxy-3-phenyloxyprobyl acrylate, 2-hydroxylethyl methacrylate, 2-hydroxybubutyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3-phenyloxyprobyl methacrylate, etc. Mention may be made of acrylic monomers having groups.

Among the monomers, styrene, styrene derivatives, methacrylic esters, acrylic esters, etc. are preferable as monomers having one vinyl group in one molecule, and in particular methacrylic acid or methacrylic acid having 1 to 5 carbon atoms in the alkyl group. Alkyl esters of acrylic acid are preferred. In vinyl monomers having two or more vinyl groups in one molecule,
Preferred are divinylbenzene, dimethacrylate and diacrylate made of methylene glycol having 2 to 6 carbon atoms, and the like.

In addition, the ratio of styrene-based components to other components is the monomer ratio (styrene-based):(other)=100:0-1
0:90, preferably 90:10 to 30:70.

These vinyl monomers are copolymerized by known methods such as suspension polymerization, emulsion polymerization, and melt-night polymerization. These copolymers preferably have a weight average molecular weight of 10,000 to 70,000. This copolymer may also be crosslinked with melamine aldehyde or isocyanate.

As a method for coating the surface of the carrier core material with the coating resin, the resin is dissolved or suspended in a solvent and applied to the surface of the core material, and the resin is adhered to the core material made of magnetic particles or the like. The method is preferred.

The processing amount of the above-mentioned coating resin depends on the film-forming properties and durability of the coating material.
Generally, the total amount is 0.1 to 30% by weight based on the carrier core material,
Preferably it is 0.5 to 20% by weight.

The toner used in the present invention includes at least a binder resin, a perylene pigment, and a C.I. I. Pigment Yellow
81. Perylene pigment and C.I. I. P
The toner containing igment Yellow 81 uses a resin-coated carrier with high electrical resistance, and even if continuous copying is performed in a low temperature environment, it will not become excessively charged and the toner will firmly adhere to the carrier. I have nothing to do.

Furthermore, perylene pigments and C.I. I. Pigment Y
The toner containing yellow 81 has a quick charge build-up, and therefore, the replenished toner quickly gains an appropriate amount of charge upon stirring and mixing with the carrier.

For the above reasons, toner does not adhere to the sensor window, and the toner concentration of the developer can be stably controlled at an appropriate value.

“Specific examples of perylene pigments include C.I.Pigm
ent Red 123. C. I. Pigment
Red 179, etc. are mentioned.

The content of the perylene pigment is preferably 2 to IO parts by weight based on 100 parts by weight of the binder resin.

More preferably, it is 3 to 8 parts by weight.

Also, C. I. The content of Pigment Yellow is preferably 0.1 to 5 parts by weight based on the binder resin.

More preferably, it is 0.3 to 3 parts by weight.

The binder resin of the toner used as a two-component developer in combination with the carrier of the present invention includes monomers of styrene and its substituted products such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene; Polymer, styrene-brobylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer,
Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacnolate copolymer, styrene-methacrylate butyl acid copolymer, styrene-acrylic-aminoacrylic copolymer, styrene-aminoacrylic copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer Polymers, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isobrene copolymer, styrene-acrylic nitrile-indene copolymer, styrene-maleic acid copolymer Polymers, styrenic copolymers such as styrene-maleate ester copolymers, polymethyl methacrylate, bobutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, bonoester, polyurecne, polyamide, epoxy resin, polyvinyl butyral , polyacrylic acid resin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. alone or in combination of two or more types as necessary. It can be used as

Furthermore, a charge control agent and a fluidity modifier may be added as necessary, and the charge control agent and fluidity modifier may be mixed (externally added) with the toner particles.

As the charge control agent, metal-containing dyes, quaternary ammonium salts, nigrosine dyes, etc. are used.

Examples of fluidity modifiers include colloidal silica and fatty acid metal salts. Also, for the purpose of tl amount, calcium carbonate,
A filler such as finely divided silica can also be incorporated into the toner in an amount of 0.5 to 20% by weight. Furthermore, in order to prevent toner particles from coagulating with each other and improve their fluidity,
A fluidity improver such as fine Teflon powder may be added, and for the purpose of improving mold releasability during hot roll fixing, additives such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, carnauba wax, Sasol wax, etc. It is also possible to add about 0.5 to 5% by weight of a waxy substance.

Note that the present invention is not limited to the examples listed here.

The toner structure described above may be used in a toner produced by a commonly used mixing and pulverizing method, or may be used in a microcapsule toner.

As the method of mixing the carrier and toner of the present invention, the commonly used d mixing method can be applied, but the toner concentration is 3 to 3
It is preferable to contain 0 parts by weight (more preferably 5 to 25 parts by weight). Within this range, the characteristics of the carrier of the present invention are well exhibited, and a sharp image with high image density can be obtained.

Next, a specific example of a developing device that can use the developer of the present invention will be described.

FIG. 1 is a schematic vertical sectional view of the developing device, and FIG. 2 is a schematic sectional view of the developing device shown in FIG.

In the figure, reference numeral 1 denotes a developer container, which is divided into a toner storage section D that stores toner and a developer storage section C that stores developer consisting of toner and carrier. The toner in the toner storage section D is supplied to the developer storage section C through the toner replenishment port 5 by the rotation of the toner conveying member 6. The toner in the developer storage section C is used to develop a replacement image formed on a photoconductor (not shown) by a developing sleeve 2, and the developing sleeve 2 has a magnetic roller 2a fixedly supported at both ends. , and a non-magnetic sleeve 2b that rotates around the sleeve 2b at a predetermined circumferential speed in the direction of the arrow.

Further, in the figure, reference numeral 30 denotes a transport pipe installed in the developer container 1, and a screw 3 for transporting the developer in the direction of the arrow is provided inside the transport pipe. 31 is the lower right end of the developer container 1 (
1) to the right end of the conveyor pipe 3o,
Inside this is a screw 4 that transports the developer in the direction of the arrow.
is provided, and the developer transported by the screw 4 is transferred from the opening 32 to the transport pipe 30.

A screw 7 is provided at the bottom of the developer container 2 to transport the new toner, the toner collected from the surface of the sleeve 2b, and the carrier to the transport pipe 31 while uniformly mixing them.

A toner concentration detecting device 20 is installed in the conveying pipe 31, and this toner concentration detecting device 20 is installed in a housing B attached to the conveying pipe 3l as shown in FIGS. 3 and 4.
Inside, a lamp 22 that irradiates light to the developer in the transport tube 31 from a window 21 formed of a transparent material of the transport tube 31, a first sensor 23 that receives reflected light reflected by the developer, and a lamp. 22, and a second sensor 24 that directly receives the light of 22.

The first and second sensors 23. Reference numeral 24 outputs a voltage according to the intensity of the light it receives, and this is composed of, for example, a photodiode, etc. When the developer has a predetermined toner concentration, the first sensor 23 outputs a voltage according to the intensity of the light it receives. The voltage vb that the second sensor 24 outputs upon receiving the light from the lamp 22 is Vb=V.
It is adjusted in advance so that it becomes c.

Next, the operation of the above-mentioned toner concentration detection device will be explained.

When the developer transported through the transport pipe 3l by the screw 4 has a toner concentration equal to or higher than a predetermined toner concentration, the sensor 23. 24
The output voltage becomes Vb>Vc, and at this time, the toner concentration detection device 20 turns off toner replenishment, and when the toner concentration is below a predetermined toner concentration, the output voltage becomes Vb<VC, and at this time, the toner concentration detection device 2o turns off toner replenishment. Turn on. By repeating these operations, the toner concentration of the developer is kept constant.

Note that the present invention is not limited to the above-mentioned developing device configuration and the above-mentioned toner concentration detection device, but is also applicable to a general type of light detection ATR that uses the principle of measuring the reflected light of the developer through a transparent window material in contact with the developer. Applicable to all developing devices.

[Example] The above mixture was melt-kneaded in a two-screw ruder heated to 150°C, then cooled, and the cooled material was coarsely pulverized in a mechanical pulverizer to the extent that it could pass through a wire mesh with an opening diameter of 1 mm. It was pulverized to about 10 gm using a jet mill.

This finely pulverized product was classified using a wind classifier 100MZR classifier so that the volume average particle diameter was 11 to 1.3 ILm.

Add positively charged silica to this at 1.0% by weight based on the classified product.
The mixture was added and combined using a Henschel mixer to obtain a toner.

was dissolved in 500 mA' of acetone:methyl ethyl ketone (1:1) mixed solvent to prepare a coating solution, and this coating solution was used to form ferrite particles (Cu-Z) with an average particle size of 60 pm.
The surface of n-ferrite coated with ZnO) was coated using a fluidized bed apparatus. After removing the solvent, it was dried at 90°C for 1 hour, and a coated carrier was obtained through post-processing.

8 parts by weight of the toner and the fluororesin-coated carrier 1
00 parts by weight were mixed to prepare a developer.

This developer was applied to a color developing device of a copying machine NP-4835 (manufactured by Canon) having a light detection ATR.

10,000 sheets were continuously copied in a low-temperature environment of 15°C and IORH%, but the toner density of the developer was controlled without changing from the beginning to the end, and the reflected image density was around 1.3 without fog. Good quality images were obtained throughout.

L sheet group Yu C. I. A developer was obtained in the same manner as in Example 1, except that Pigment Yellow 81 was not used, and images were produced in the same manner as in Example 1.

Initially, the reflected image density was 1.30, but because toner adhered to the sensor window and the ATR malfunctioned, the image density gradually decreased after 8,000 copies, and the image density after 10,000 copies was has fallen to l,22.

Ratio 1: Instead of perylene pigments, lake-based azo pigments (C.I.
．． A developer was obtained in the same manner as in Example 1, except that Pigment Red 48-1) was used, and images were formed in the same manner as in Example 1.

Initially, the reflected image density was 1.30, but because toner adhered to the sensor window and the ATR malfunctioned, the image density gradually decreased after 5,000 copies, and the image density decreased to 1.30.
It dropped to lO.

Tsuji 1u fatan C. I. Pigment Yellow 81 instead of C. I. A developer was obtained in the same manner as in Example 1 except for using Pigment Yellow 10,
Imaging was carried out in the same manner as in Example 1.

Initially, the reflected image density was 1.30, but because toner adhered to the sensor window and the ATR malfunctioned, the image density gradually decreased after 8,000 copies, and the image density decreased to 1.30.
It dropped to 23.

Mitsushi Yuperylene pigment C. T. Pigment Red 17
9, perylene pigment C. I. Pigment
A developer was obtained in the same manner as in Example 1, except that Red 123 was used, and an image was formed in the same manner as in Example 1.

Good results similar to those in Example 1 were obtained.

[Effects of the Invention] According to the present invention, it is possible to prevent toner from adhering to the sensor window and malfunction of the ATR, and therefore it is suitable for a developing device having an ATR device.

[Brief explanation of drawings]

Fig. 1 is a schematic longitudinal sectional view of the developing device, Fig. 2 is a schematic sectional view of the developing device shown in Fig. 1, Figs. 3 and 4 are explanatory diagrams of the toner concentration detection device, and Fig. 5 is a photodetection device. FIG. 3 is a diagram illustrating an example of a toner concentration detection section of the ATR method.

Claims (1)

[Claims] It is used in a developing device having a photo-sensing automatic toner concentration control device, and contains at least perylene pigments and C.I. I. Pigm
A developer containing a non-magnetic toner containing entYellow81 and a binder resin, and a carrier formed by coating magnetic particles with the resin.