JPH05297628A - Developer and image forming method - Google Patents

Abstract

PURPOSE:To improve the fixability of the developer to the surface of a developer carrying member and to prevent the electrostatic charge defect of the developer by specifying the heating loss of the developer and the developer carrying member. CONSTITUTION:The resin layer 4 contg. conductive particulates is formed on the surface of the developer carrying member 2 which carries a toner 5 and transports the toner to a development region formed between the carrying member and a photosensitive drum 1. The heating loss up to 300 deg.C of the resin layer 4 is confined to <=2wt.% of the weight over the entire part of the resin layer 4. The toner 5 of the developer contains a binder resin and coloring agents and is so formed that the heating loss up to 150 deg.C of the developer is <=0.15wt.% of the weight over the entire part of the developer. Not only the fixability of the developer onto the developer carrying member 2 is promoted but the electrostatic chargeability is impaired as well if the percentage content of the volatile component in the resin layer 4 exceeds 2wt.% and, therefore, the weight % of the heating loss is required to be precisely controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a developing device for forming a latent image on an image bearing member such as an electrophotographic photosensitive member or an electrostatic recording dielectric member and developing the latent image. The present invention relates to an agent or an image forming method using them.

[0002]

2. Description of the Related Art Conventionally, for example, a developing device for visualizing a latent image formed on a surface of a photosensitive drum as an electrostatic latent image bearing member with a magnetic toner as a one-component developer has been known. Due to friction and friction between the sleeve as a developer carrier and the magnetic toner particles, a charge having a polarity opposite to that of the electrostatic image charge formed on the photosensitive drum is given to the magnetic toner particles, and the magnetic toner is applied very thinly on the sleeve. Then, the toner is carried to the developing area formed by the photosensitive drum and the sleeve, and the magnetic toner is caused to fly by the action of the magnetic field of the magnet fixed in the sleeve in the developing area to visualize the electrostatic latent image on the photosensitive drum. Things are known.

[0003]

However, in each of the developing devices as described above, a relatively thin and uniform toner layer must be formed on the sleeve, but the environmental condition, the toner physical properties, and the condition of the sleeve surface are required. Etc.,
A uniform toner layer cannot be obtained, and unevenness often occurs especially in a low humidity environment.

As the copying is repeated, the developer is repeatedly rubbed against the sleeve, and as a result, additives for improving the fluidity of the toner and non-developing substances such as carriers in the two-component developer are deposited on the sleeve. Or, the surface condition of the sleeve changes because the binder resin in the developer forms a film on the sleeve, and the developability of the developer becomes unstable,
Alternatively, there is a problem that the conveyance of the developer to the electrostatic latent image surface becomes unstable.

In order to prevent such a change in the surface state of the sleeve, for example, a coating layer containing an inorganic polymer carbon fluoride (Japanese Patent Laid-Open No. 57-66443), silica is dispersed. At least one selected from the group consisting of a resin forming a resin having a good releasability (Japanese Patent Laid-Open No. 58-178380), an organic silicone polymer, an aliphatic fluorine-containing compound, a styrene resin, and polyphenylene oxide, and 2 To form a coating containing a metal complex having a hexadentate ligand (JP-A-57-76558)
Japanese Patent Laid-Open Publication No. 2003-242242, etc., there has been proposed a method for preventing the change of the surface state by coating the surface of the sleeve with a substance having particularly high releasability.

However, in the case of a coated sleeve in which the surface of the sleeve is coated with these synthetic resins or the like, compared with the conventionally used sleeve made of aluminum or SUS,
Relatively obviously soft. Therefore, the developer is pressed during repeated development operations, which is remarkable especially in the case of a magnetic developer containing a magnetic material, but the surface of the developer carrying member is unevenly polished or scratched. However, there is a problem in that the performance originally possessed by the coated sleeve is likely to be deteriorated due to the formation of stains or the deposition of a part of the developer.

On the other hand, the developer is fixed on the transfer material by heat fusion fixing by a heat roller or radiant heating, pressure fixing by a pressure roller, etc., but heat quantity and pressure are economical and safety / design of the apparatus structure. In consideration of easiness, it is preferable that it is small, and accordingly, a so-called soft component having a low melt viscosity, a low melting point, a low pressure yield point, etc. tends to be included as a component of the developer. On the contrary, in terms of durability and fixing offset, it is also important that the developer contains a hard component.

In order to satisfy such contradictory factors, it is often advantageous that the binder resin constituting the developer contains both a soft portion and a hard portion in its molecular weight distribution.

Such a tendency of the developer has a great possibility of making the above-mentioned problems of the developer carrying member remarkable, and is designed in consideration of applicability between the developer carrying member and the developer. , Easy to become difficult.

Further, recently, in order to obtain a high-quality image, the particle size of the developer tends to be small. In the image forming apparatus using the developer having such a small particle size, the developer carrying member is used. When a DC voltage or a DC voltage superimposed with an AC voltage is applied between the photosensitive drum and a latent image carrier such as a photoconductor drum, the number of times of repeated flight of the developer and rubbing increases in the developing area. Therefore, the developer may be fixed or embedded on the surface of the coat sleeve, and further, the developer and the developer carrier may be easily contaminated with each other, which may make the above problems of the developer carrier more remarkable. Is very large.

The present invention solves the above problems,
An object of the present invention is to provide a developer that can be uniformly carried on the surface of a sleeve, and an image forming method using the developer.

[0012]

According to the present invention, the above-mentioned object is to contact a developer containing toner in a developer accommodating chamber, and to hold the developer on the surface to form an electrostatic latent image carrier. In the image forming method using a developing device in which the surface of the developer carrying member conveyed to the developing region formed by is coated with a resin layer containing conductive fine particles, the heating loss up to 300 ° C. It is 2% by weight or less of the total weight of the resin layer, and the toner of the developer contains at least a binder resin and a colorant, and the heating weight loss of the developer up to 150 ° C. is It is achieved by a developer characterized by being 0.15% by weight or less, and an image forming method.

In order to prevent the developer from sticking to the surface of the coated sleeve, it is necessary to precisely control the weight% of the heating loss of the developer and the resin coating layer of the coated sleeve.

The loss on heating is the amount of weight loss when the sample is gradually heated under a certain atmosphere, and can be measured by, for example, a thermobalance.

In the present invention, the weight loss upon heating is represented by the weight loss when a sample is heated at a heating rate of 10 ° C./min in a nitrogen stream using PE7700 and TGA7 manufactured by Perkin Elmer.

The developing device used in the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of an example of the developing device of the present invention.

Reference numeral 1 in the drawing denotes a photosensitive drum as an electrostatic latent image carrier that carries an electrostatic latent image and rotates in the direction of arrow A, both with and without an insulating layer on the surface. It can be used and of course not only drum shape but sheet shape,
A belt shape is also possible. Reference numeral 2 is a sleeve as a developer carrying member that carries the toner 5 on its surface and rotates in the direction of arrow B. Inside the sleeve 2, a multi-pole permanent magnet 3 is provided.
Is fixed so that it does not rotate. Also, the sleeve 2
A resin coating layer 4 containing conductive fine particles, which will be described later, is formed on the surface of 1 to have a thickness of about 0.5 μm to 30 μm. Reference numeral 6 denotes a doctor blade as a member that regulates the layer of the toner 5 on the surface of the carried sleeve 2 to a predetermined thickness, so that the gap between the surface of the sleeve 2 and the doctor blade 6 is about 50 μm to 500 μm. It is arranged.

When the developing device constructed as described above is activated and the sleeve 2 rotates in the direction of the arrow B, the toners 5 or the surface of the sleeve 2 and the toner 5 are in the developer accommodating chamber.
Due to the contact friction of the toner, a charge having a polarity opposite to that of the electrostatic latent image on the photosensitive drum 1 is applied to the toner 5 and is applied to the surface of the sleeve 2. The toner layer applied on the sleeve surface is
The multi-pole permanent magnet 3 is regulated to have a uniform and thin layer (layer thickness is about 30 μm to 300 μm) by a doctor blade 6 arranged so as to face one magnetic pole (S pole in the figure) position, and is exposed. It is conveyed to a developing area formed by the drum 1 and the sleeve 2.

Further, in the developing area, an AC bias may be applied between the sleeve 2 and the surface of the photosensitive drum 1 to cause the toner 5 on the sleeve 2 to fly toward the photosensitive drum.

Here, the resin coating layer 4 formed on the surface of the sleeve will be described.

As the resin layer, a film-forming polymer material containing conductive fine particles is used, and the weight loss upon heating up to 300 ° C. is 2% by weight or less of the whole resin layer, and further sufficient performance is obtained. In order to take it out, it is preferable to make it 1% by weight or less. The weight loss of the resin layer due to heating is due to residual monomers, low-molecular weight oligomers, reaction catalyst residues, and as required, which are generated during the coating process for synthesizing the film-forming polymer material described below or during the coating treatment during the production of the coat sleeve. This is because volatile components such as an organic solvent escape from the resin layer by heating. As a result of studies by the present inventors, when the content of these volatile components in the resin layer exceeds 2% by weight, not only the adhesion of the developer to the developer carrying member is promoted but also the charging property is improved. It became clear that it also inhibits.

The conductive fine particles added to the resin layer are preferably carbon fine particles, or carbon fine particles and crystalline graphite, or crystalline graphite.

The crystalline graphite used in the present invention is roughly classified into natural graphite and artificial graphite. Artificial graphite is made by solidifying pitch coke with tar pitch or the like, firing it once at about 1200 ° C, and then putting it in a graphitization furnace.
By processing at a high temperature of about 300 ° C., carbon crystals grow and change into graphite. Natural graphite is completely graphitized from the ground due to natural geothermal heat and underground high pressure for a long time. These graphites have a wide range of industrial uses because they have various excellent properties. Graphite is a dark gray or black glossy, very soft and crystalline mineral that is used for pencils and has other heat resistance and chemical stability, so it is used as a powder for lubricants, fire resistance, electrical materials, etc. It is used in the form of solids and paints. The crystal structure is hexagonal and others belong to the rhombohedral system,
It has a completely layered structure. Regarding electrical characteristics,
Free electrons exist between the carbon-carbon bonds and are good conductors of electricity. The graphite used in the present invention may be natural or artificial.

The graphite used in the present invention preferably has a particle size of 0.5 μm to 10 μm.

Examples of the film-forming polymer material include styrene resin, vinyl resin, polyether sulfone resin, polycarbonate resin, polyphenylene oxide resin,
Thermosetting of thermoplastic resins such as polyamide resin, fluororesin, fibrin resin, acrylic resin, epoxy resin, polyester resin, alkyd resin, phenol resin, melamine resin, polyurethane resin, urea resin, silicone resin, polyimide resin, etc. Resin or photo-curable resin can be used. Among them, those having a releasing property such as silicone resin and fluororesin, or those having excellent mechanical properties such as polyether sulfone, polycarbonate, polyphenylene oxide, polyamide, phenol, polyester, polyurethane and styrene resin are more preferable. ..

Conductive amorphous carbon is generally defined as "an aggregate of crystallites formed by burning or pyrolyzing a hydrocarbon or a compound containing carbon in a state where the air supply is insufficient". .. In particular, it is widely used because it has excellent electric conductivity, and it can be filled with a polymer material to give conductivity, or it can obtain an arbitrary conductivity to some extent by controlling the amount added. The particle diameter of the conductive amorphous carbon used in the present invention is preferably 10 μm to 80 μm, more preferably 15 μm to 40 μm.

The sleeve of the present invention has a thickness of about 0.5 formed by spraying a prepared liquid as shown in the following formulation example on the surface of a raw pipe (surface roughness 2S) after aluminum drawing.
The coating treatment can be performed in a step of coating about 30 μm, and then heat curing in a drying furnace. The method for reducing the volatile components in the resin layer is achieved by adjusting the heating temperature and the heating time during the heat treatment such as the above-mentioned thermosetting step.

Formulation Example 1 Resin: Phenol resin (solid content) 30 parts by weight Carbon: Amorphous carbon (CONDUCTEX975UB manufactured by Colombian Carbon Co.) 5 parts by weight Conductive lubricant: Artificial graphite (2 μm) 25 parts by weight Diluent: Methyl alcohol / Methylcellosolve 200 parts by weight Formulation Example 2 Resin: phenol resin (solid content) 15 parts by weight Conductive lubricant: Artificial graphite (1 μm) 15 parts by weight Diluent: Methyl alcohol / methylcellosolve 225 parts by weight Formulation Example 3 Resin: phenol Resin (solid content) 30 parts by weight Conductive lubricant ... Artificial graphite (1 μm) 15 parts by weight Diluent ... Methyl alcohol / methyl cellosolve 225 parts by weight Resin prepared through the steps of the above prescription examples 1 to 3 Up to 300 ℃ of resin layer of coat sleeve Percentage of the total weight of the heat loss, and the heat curing conditions are summarized in Table 1 below.

[0030]

[Table 1] Next, a developer applicable to the developing step, the transferring step, and the cleaning step in the image forming method of the present invention will be described.

The developer according to the present invention has a weight loss on heating up to 150 ° C. of not more than 0.15% by weight, preferably not more than 0.10% by weight, more preferably not more than 0.05% by weight.
It must be below wt%. The weight loss of the developer due to heating is caused by residual monomers, low molecular weight oligomers, reaction catalyst residues, and volatile compounds such as organic solvents used as necessary, which are generated during the synthesis of the binder resin composition described later. ..

The developer of the present invention, having the above-mentioned constitution, is extremely unlikely to adhere to the surface of the developer carrying member and exhibits good charging characteristics.

From the above, the developer according to the present invention is
It has been found that there is provided an image forming method in which the matching with the developer carrying member according to the present invention is extremely good, the capability of the developing step according to the present invention is sufficiently exerted, and good image formation is always performed.

Although various known techniques can be used as a specific method for reducing the volatile components,
To reduce the residual monomer and organic solvent contained in the developer, when manufacturing the developer, for example, when heat-kneading the binder resin and the colorant, etc., heat strongly or remove by suction. The way to do is good.

The binder resin for toner used in the present invention preferably contains 10 to 70% by weight of THF insoluble matter, and the THF soluble matter has a molecular weight of 10,000 in GPC.
The proportion of components of 0 or less is preferably 10 to 50% by weight, and preferably 20 to 39% by weight. In order to obtain sufficient performance, the molecular weight is 10,000 or less and 2,000
It is preferable to have a peak in the above range (preferably 2,000 to 8,000) and a peak or shoulder in the range of molecular weight 15,000 to 100,000 (preferably 20,000 to 70,000). ..

The ratio of components having a molecular weight of 10,000 or less is 5
If it exceeds 0% by weight, the toner is apt to adhere to the device during the step of applying the toner onto the developer carrier, and
If the insoluble content is less than 10% by weight, the tendency is more remarkable.

When the THF insoluble content exceeds 70% by weight, the strength of the toner itself becomes too large and the surface of the developer carrying member may be damaged. Molecular weight is 10,
If the proportion of the components of 000 or less is less than 10% by weight, it will be even larger.

From the above, the molecular weight distribution of the binder resin as described above is preferable in order to prevent the problems caused by the coat sleeve system as the developer for heat fusion fixing.

The THF-insoluble matter in the present invention means the weight ratio of the polymer component (substantially cross-linked polymer) which becomes insoluble in the THF solvent in the resin composition in the toner,
It can be used as a parameter indicating the degree of crosslinking of the resin composition containing the crosslinking component. The THF-insoluble matter is defined as a value measured as follows.

That is, 0.5 to 1.0 g of a toner sample is weighed (W ₁ g), and a cylindrical filter paper (for example, No.
86R) and put on a Soxhlet extractor, and extracted with 100 to 200 ml of THF as a solvent for 6 hours to evaporate soluble components extracted by the solvent,
After vacuum drying at 100 ° C. for several hours, the amount of the THF-soluble resin component is weighed (W ₂ g). The weight of the components other than the resin component such as the magnetic substance or pigment in the toner is (W ₃ g). TH
The F insoluble content is obtained from the following formula.

THF insoluble matter (%) = [W ₁ − (W ₃ + W
₂ )] / (W ₁ -W ₃ ) × 100 In the present invention, the molecular weight of the peak or / and shoulder of the chromatogram by GPC (gel permeation chromatography) is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C., and THF (tetrahydrofuran) as a solvent was flown through the column at this temperature at a flow rate of 1 ml / min to obtain a sample concentration of 0.05 to 0.6% by weight. 50-200 μl of a THF sample solution of the resin adjusted to 1 is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared using several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for creating a calibration curve,
For example, Pressure Chemical Company (Pressure C
chemical Co. ) Or manufactured by Toyo Soda Kogyo Co., Ltd. having a molecular weight of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ ,
1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ ,
3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.4
It is appropriate to use a standard polystyrene sample of at least 10 points, using 8 × 10 ⁶ . An RI (refractive index) detector is used as the detector.

The column is 10 ³ to 4 × 10 ^6.
In order to accurately measure the molecular weight range of the polystyrene gel, it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, μ-styragel (Waters).
^{ragel) 500,10 3, 10 4,} 10 5 of combinations and, Showa Denko Corp. Shodex (shodex) K
F-80M, KF-802, 803, 804, 805
Or TOSgel G100 made by Toyo Soda
0H, G2000H, G2500H, G3000H, G
4000H, G5000H, G6000H, G7000
A combination of H and GMH is preferred.

The weight% of the binder resin of the present invention having a molecular weight of 10,000 or less is cut out from a molecular weight of 10,000 or less in the chromatogram by GPC, and the weight ratio with the cutout having a molecular weight of 10,000 or more is calculated. Use the weight% of insoluble matter, and weight% of the total binder resin
To calculate.

As the binder resin composition of the toner according to the present invention, those obtained by polymerizing one or more kinds of monomers selected from styrenes, acrylic acids, methacrylic acids and their derivatives are the developing characteristics and charging characteristics. Is preferred.
Examples of monomers that can be used include styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene. Acrylic acids, methacrylic acids and their derivatives include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-tetradecyl acrylate, n-acrylate. Acrylic esters such as hexadecyl, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, etc. can be mentioned, as well as methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate. , Amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, silyl methacrylate. Rohekishiru, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, glycidyl methacrylate, methacrylic acid esters such as stearyl methacrylate. In addition to the above-mentioned monomers, a small amount of other monomers such as acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, vinylcarbazole, vinylmethyl ether, butadiene, isoprene, maleic anhydride, malein within a range that can achieve the object of the present invention. Acids, maleic acid monoesters, maleic acid diesters, vinyl acetate and the like may be used.

As the cross-linking agent used in the resin for toner of the present invention, as a bifunctional cross-linking agent, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-
Butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene Glycol diacrylate, polyethylene glycol # 200, # 400, #
Examples include 600 diacrylates, dipropylene glycol diacrylates, polypropylene glycol diacrylates, polyester type diacrylates (MANDA Nippon Kayaku), and those obtained by replacing the above acrylates with methacrylates.

As a polyfunctional crosslinking agent, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, poly Ethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate,
Examples thereof include triallyl assocyanurate, triallyl isocyanurate, triallyl trimellitate, and diaryl chlorendate.

The method for synthesizing the binder resin according to the present invention is TH
A suspension polymerization method is preferable for adjusting the F insoluble content, but a method of basically synthesizing two or more kinds of polymers is preferable for adjusting the molecular weight distribution.

That is, a resin composition containing a cross-linking region component obtained by dissolving a first polymer soluble in THF and soluble in a polymerization monomer in a polymerization monomer containing a cross-linkable monomer and polymerizing the monomer. Is a way to get. In this case, since the former polymer and the latter polymer are uniformly mixed, when the resin is applied to the toner, it is possible to improve the fixing / offset property without deteriorating the durability and blocking resistance of the toner. Is possible.

The first polymer soluble in THF is preferably solution-polymerized or ionic polymerized, and the second polymer for producing a component insoluble in THF is obtained by dissolving the first polymer. It is preferable to synthesize by suspension polymerization or bulk polymerization in the presence of a crosslinkable monomer under certain conditions. The first polymer is a polymerizable monomer 100 for forming the second polymer.
10 to 120 parts by weight (preferably 20 to 100 parts by weight)
Parts by weight) It is preferable to use parts by weight.

In the toner using the resin of the present invention, in addition to the above-mentioned binder resin component, the following compounds are contained in a proportion smaller than the content of the binder resin component within a range not adversely affecting the effects of the present invention. May be included.

For example, silicone resin, polyester,
Polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin such as low molecular weight polyethylene or low molecular weight polypropylene, aromatic petroleum resin, chlorinated paraffin, For example, paraffin wax.

As the colorant contained in the toner according to the present invention, generally known dyes and pigments can be used.
Examples of such dyes and pigments include carbon black, nigrosine dye, lamp black, Sudan black S
M, First Yellow G, Benzidine Yellow,
Pigment Yellow, India First Orange,
Irgadine Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resor Red 2G, Lake Red C, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow G
G, Zapon First Yellow CGG, Kayaset Y
963, Kayaset YG, Sumiplast Yellow G
G, Zapon Fast Orange RR, Oil Scarlet, Sumiplast Orange G, Orazol Brown B, Zapon Fast Scarlet CG, Eisenspiron Red BEH, Oil Pink OP, etc. can be applied. These colorants are generally used in order to obtain a capsule toner for a two-component developer, and it is preferable to add them in a ratio of 5 to 20% with respect to the core binder.

The magnetic fine particles to be contained when the developer of the present invention is used as a magnetic toner include a metal made of a ferromagnetic element such as ferrite, magnetite or other iron, cobalt, nickel, or an alloy containing the same. Compounds or alloys that do not contain strong magnetic elements, but become ferromagnetic by suitable heat treatment, such as manganese-copper-aluminum or manganese-copper-
Examples include alloys of the type called Heusler alloys containing manganese such as tin and copper, or chromium dioxide. The content ratio of the fine powder of these magnetic materials can be 70 to 130 parts by weight with respect to 100 parts by weight of the binder resin. The magnetic fine particles can also be used as a black or brown pigment.

As the charge control agent contained in the toner according to the present invention, a conventionally known charge control agent is selected. Specific examples of the positive charge control agent generally include nigrosine and C2.
Azine dyes containing 16 to 16 alkyl groups (Japanese Examined Patent Publication No.
1627), basic dyes (for example, CI Basic Yellow 2 (C.I. 41000), C.I.
Basic Yellow 3, C.I. I. Basic Red 1 (C.I. 45160), C.I. I. basic
Red 9 (C.I. 42500), C.I. I. Basic Violet 1 (C.I. 42535), C.I.
I. Basic Violet 3 (C.I.
5), C.I. I. Basic Violet 10 (C.
I. 45170), C.I. I. Basic Violet 14 (CI.42510), C.I. I. basic
Blue 1 (C.I. 42025), C.I. I. Basic Blue 3 (C.I. 51005), C.I. I. Basic Blue 5 (C.I. 42140), C.I. I. Basic Blue 7 (C.I. 42595), C.I.
I. Basic Blue 9 (C.I. 52015),
C. I. Basic Blue 24 (C.I.5203
0), C.I. I. Basic Blue 25 (C.I.5
2025), C.I. I. Basic Blue 26 (C.
I. 44025), C.I. I. Basic green 1
(C.I. 42040), C.I. I. Lake pigments of these basic dyes such as Basic Green 4 (C.I. 42000) (as lakers, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricia) Compound, ferrocyanide, etc.), C.I. I. Solvent
Black 3 (C.I. 26150), Hansa Yellow G (C.I. 11680), C.I. I. Modrant Black 11, C.I. I. Pigment Black 1st.

Or, for example, a quaternary ammonium salt such as benzolmethyl-hexadecyl ammonium chloride or decyl-trimethyl ammonium chloride or a vinyl resin containing an amino group, a polyamide resin such as a condensation polymer containing an amino group, etc. may be mentioned. Of these, nigrosine, quaternary ammonium salts, triphenylmethane-based nitrogen-containing compounds and polyamides are preferable.

Further, specific examples of the negative charge control agent include JP-B-41-20153, JP-B-42-27596, and JP-B-42-27596.
Metal complexes of monoazo dyes described in JP-A Nos. 4-6397 and 45-26478, and JP-A-50-1
Nitramic acid and salts thereof described in No. 33338 or C.I. I. Dyes and pigments such as 14645, Japanese Patent Publication Sho 55
-42752, Japanese Patent Publication 58-41508, Japanese Patent Publication 5
Z-7 of salicylic acid, naphthoic acid and dicarboxylic acid described in JP-B-8-7384 and JP-B-59-7385.
Examples thereof include metal complexes of n, Al, Co, Cr and Fe, sulfonated copper phthalocyanine pigments, nitro groups, halogen-introduced styrene oligomers and chlorinated paraffins. Particularly, from the viewpoint of dispersibility, metal complex salts of monoazo dyes, metal complexes of salicylic acid, alkylsalicylic acid, naphthoic acid, and dicarboxylic acid are preferable. The addition amount of these charge control agents keeps good triboelectricity as described above, and minimizes the adverse effects such as the reduction of the developing power and the environmental stability due to the contamination of the surface of the developing sleeve by the charge control agents. Therefore, the addition amount of 0.1 to 3 parts by weight is preferable with respect to 100 parts by weight of the binder resin.

As a fixing auxiliary agent for the toner according to the present invention,
The ethylene-based olefin polymer may be used together with the binder resin.

The ethylene-based olefin homopolymer or ethylene-based olefin copolymer used herein includes polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer. Examples of the copolymer include an ionomer having a polyethylene skeleton, and the above copolymer preferably contains an olefin monomer in an amount of 50 mol% or more (more preferably 60 mol% or more).

Next, an electrophotographic method to which the developer of the present invention is applied will be described.

In the step of developing the electric latent image with toner, the magnetic brush method, the cascade developing method, the powder cloud method, and the conductive property described in US Pat. No. 3,909,258 are mentioned. Method using magnetic toner of JP
There is a method using a high-resistance magnetic toner described in Japanese Patent No. 31136. The toner according to the present invention is also suitable for a developing method using a so-called one-component developer containing magnetic particles. A corona transfer method, an electrostatic transfer method such as a bias application method to a contact transfer member, or the like is used in the step of transferring the developed image to the transfer target member.

By the way, in recent years, a method of charging and / or transferring and / or discharging, which uses corona discharge from a member which is not in contact with the photosensitive member, onto the photosensitive member involves generation of ozone. A method of applying a bias directly through a contact member is drawing attention. With the shift to such a method, there is a possibility that the activated carbon filter that was often attached to the conventional copying machine / printer may be removed. It has a remarkable effect.

Further, in the toner according to the present invention, a blade cleaning method, a fur brush cleaning method or the like is applied to the step of removing the residual toner on the photosensitive layer or the insulating layer, and is particularly suitable for the blade cleaning method. There is.

[0064]

EXAMPLES The basic structure and features of the present invention have been described above. The method of the present invention will be specifically described below based on examples. However, the embodiments of the present invention are not limited to these. All parts in the examples are parts by weight.

Synthesis Example 1 200 parts of cumene was placed in a reactor and heated to the reflux temperature. A mixture of 100 parts of styrene monomer and 7 parts of benzoyl peroxide was added dropwise to the mixture under reflux of cumene over 4 hours. Further under cumene reflux (146 ° C to 156 ° C)
Solution polymerization was completed at (° C.) to remove cumene. The obtained polystyrene was soluble in THF, the molecular weight at which the main peak of GPC was located was 3,500, and Tg was 56 ° C.

30 parts of the above polystyrene was dissolved in the following monomer mixture to obtain a mixed solution.

Styrene monomer 50 parts N-butyl acrylate monomer 20 parts Divinylbenzene 0.3 parts Di-tert-butyl peroxide 2 parts Polyvinyl alcohol partially saponified product 0.
170 parts of water in which 1 part was dissolved was added to obtain a suspension dispersion.
The suspension dispersion was added to a reactor in which 15 parts of water was charged and the atmosphere was replaced with nitrogen, and a suspension polymerization reaction was carried out at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, it was filtered, dehydrated and dried to obtain a composition of polystyrene and a styrene-n-butyl acrylate copolymer. In the composition, the THF insoluble matter and the THF soluble matter were uniformly mixed, and the polystyrene and the styrene-n-butyl acrylate copolymer were uniformly mixed. THF insoluble matter of the obtained resin composition (24 mesh pass, 60
(Measured with mesh-on powder) was 30% by weight.
In addition, the molecular weight distribution of the THF-soluble component was measured to find that GPC
In the chart, the peaks were at positions of about 40,000 and about 40,000, and the molecular weight of 10,000 or less was 25% by weight. Furthermore, the Tg of the resin was 57 ° C.

Synthesis Example 2 150 parts of cumene was placed in a reactor and heated to a reflux temperature. The following mixture was added dropwise under a cumene reflux for 4 hours.

Styrene monomer 95 parts n-butyl acrylate monomer 5 parts Di-tert-butyl peroxide 4 parts Further, the polymerization was completed under cumene reflux (146 to 156 ° C.) to remove cumene. The obtained styrene-n-butyl acrylate copolymer had a main peak at a position of molecular weight 2,200 and had Tg = 55 ° C.

35 parts of the styrene-n-butyl acrylate copolymer was dissolved in the following monomer mixture to obtain a mixture.

Styrene monomer 45 parts N-butyl methacrylic acid monomer 20 parts Divinylbenzene 0.25 part Benzoyl peroxide 1 part Polyvinyl alcohol partially saponified product 0.1 to the above mixture.
170 parts of water having parts dissolved therein was added to obtain a suspension dispersion liquid.

The above dispersion was added to a reactor in which 15 parts of water was charged and the atmosphere was replaced with nitrogen, and the reaction was carried out at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, the mixture was filtered, dehydrated and dried to obtain a homogeneous mixed composition of a styrene-n-butyl acrylate copolymer and a styrene-n-butyl methacrylic acid copolymer.

The obtained resin composition had a THF insoluble content of 20% by weight, the THF soluble content had peaks on the GPC chart of about 0.3 million and about 30000, and a molecular weight of 10,000 or less was 35% by weight. It was ℃.

Synthesis Example 3 35 parts of the styrene-n-butyl acrylate copolymer obtained in Synthesis Example 2 was dissolved in the following monomer mixture to obtain a mixture.

Styrene monomer 45 parts 2-Ethylhexyl acrylate monomer 20 parts Divinylbenzene 0.25 part Benzoyl peroxide 1 part Polyvinyl alcohol partially saponified product 0.1 to the above mixture.
170 parts of water having parts dissolved therein was added to obtain a suspension dispersion liquid.

The above dispersion liquid was added to a reactor in which 15 parts of water was charged and the atmosphere was replaced with nitrogen, and the reaction was carried out at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, the mixture was filtered, dehydrated and dried to obtain a homogeneous mixed composition of a styrene-n-butyl acrylate copolymer and a styrene-n-butyl methacrylic acid copolymer.

The obtained resin composition had a THF insoluble content of 10% by weight, a THF soluble content of GPC chart peaks of about 255,000 and about 25,000, a molecular weight of 10,000 or less was 40% by weight, and a resin Tg55. It was ℃.

Comparative Synthetic Example 1 In the same production method as in Synthetic Example 1, only the polymerization temperature was adjusted, and THF was used.
A resin composition was obtained in which the insoluble content was 8% by weight, the peak positions in the GPC chart of the THF-soluble content were about 40,000 and about 38,000, the molecular weight of 10,000 or less was 30% by weight, and the resin Tg was 50 ° C.

[0079] Example 1 Synthesis Example 1 of Resin composition 100 parts magnetic fine powder (average particle size 0.3 [mu] m) were mixed 100 parts of the negatively chargeable monoazo dye 1 part low molecular weight polypropylene 3 parts The above raw materials 500mmHg under reduced pressure, The kneaded material was melted and kneaded at a temperature of 200 ° C., cooled, pulverized and classified to obtain a magnetic fine particle classified powder having a volume average particle diameter of 7 μm. Negatively chargeable colloidal silica 0.
9 parts were dry mixed to obtain a developer. 150 of this developer
The weight loss on heating to 0 ° C was 0.04% by weight based on the total weight.

Next, using this developer, a commercially available laser
Using the printer LBP-SX (Canon) modified to change the developer carrying member to that of Formulation Example 1, images were formed by reversal development method at a continuous printing speed of 4000 times at a printing speed of 4 sheets (A4) / minute. Forming live-action tests were performed to evaluate the printout images. At the same time, the state of the surface of the developer carrying member was observed.

As a result, the developer was not fixed on the surface of the developer carrying member. The obtained image was good and excellent in reproducibility of fine lines.

[0082] After mixing the Example 2 Synthesis Example 2 of Resin composition 100 parts magnetic fine powder (average particle size 0.4 .mu.m) 100 parts negatively chargeable monoazo dye 1 part low molecular weight polypropylene 3 parts The above raw materials, 350 mmHg under reduced pressure A developer was prepared in the same manner as in Example 1, except that the kneaded material was melted and kneaded at a temperature of 200 ° C. The heating loss of this developer up to 150 ° C. was 0.10% by weight based on the total weight.

Next, using this developer, a continuous 3000-sheet print-out test was conducted in the same manner as in Example 1 except that the developer carrier was changed to that of Formulation Example 2.

As a result, the developer was not fixed on the surface of the developer carrying member. The image obtained was good.

[0085] Example 3 Resin composition 100 parts magnetic fine powder of Synthesis Example 3 (average particle diameter 0.3 [mu] m) were mixed 100 parts of the negatively chargeable monoazo dye 1 part low molecular weight polypropylene 3 parts The above raw materials, Example 2 A developer was prepared in the same manner as in. The heating loss of this developer up to 150 ° C. was 0.14% by weight based on the total weight.

Next, using this developer, a printout test was conducted on 3000 continuous sheets in the same manner as in Example 2. As a result, dot-like adhered substances were observed at several places on the surface of the developer carrying member. However, no image defects were found on the image,
There was no problem in practice.

Comparative Example 1 Continuous 30 was carried out in the same manner as in Example 1 except that the developer of Example 3 was used and the developer carrier was that of Formulation Example 3.
A printout test of 00 sheets was performed. As a result, adhered matter was observed on the surface of the end portion of the developer carrying member. Further, the obtained image lacked sharpness and had a fog phenomenon in the non-image portion.

Comparative Example 2 Resin composition of Comparative Synthesis Example 1 100 parts Magnetic fine powder 100 parts Negatively charging monoazo dye 1 part Low molecular weight polypropylene 3 parts After mixing the above raw materials, the kneaded material temperature was set to 200 ° C. under a reduced pressure of 500 mmHg. A developer was prepared in the same manner as in Example 1 except that the melt-kneading was performed. The weight loss on heating of this developer up to 150 ° C. was 0.50% by weight based on the total weight.

Next, this developer was subjected to a printout test in each environment in the same manner as in Example 3. As a result, adhered matter was observed on the surface of the end portion of the developer carrying member. Further, the obtained image had a fog phenomenon in the non-image portion.

[0090]

According to the present invention, not only the fixing property of the developer to the surface of the developer carrying member can be improved, but also the charging failure of the developer can be prevented and a good image can be always formed.

[Brief description of drawings]

FIG. 1 is a schematic view of a copying apparatus that carries out an image forming method of the present invention.

[Explanation of symbols]

 1 electrostatic latent image carrier (photosensitive drum) 2 developer carrier (sleeve) 3 multi-pole permanent magnet 4 resin coating layer 6 doctor blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Otake 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiyoko Tsuchiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Co., Ltd. (72) Inventor Hiroyuki Suematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A resin layer containing at least conductive fine particles is provided on the surface thereof, and the weight loss on heating of the resin layer up to 300 ° C. is 2% by weight or less of the total weight of the resin layer.
A developer applied to an image forming method using a developing device having a developer carrier for carrying and carrying a developer, wherein the toner of the developer contains at least a binder resin and a colorant. And a heating loss up to 150 ° C. of the developer is 0.15% by weight or less based on the total weight of the developer. 2. A developer having at least a resin layer containing conductive fine particles on its surface and carrying a developer whose weight loss on heating up to 300 ° C. is 2% by weight or less of the total weight of the resin layer. An image forming method using a developing device having a developer carrying member for carrying out the development, wherein the toner of the developer contains at least a binder resin and a colorant, and the heating loss of the developer up to 150 ° C. Is 0.15% by weight or less based on the total weight of the developer.