JPH022577A - Binder resin for toner, toner, developer, and image forming method - Google Patents

Abstract

PURPOSE:To obtain the toner which obviates the degradation of the electrostatic charge potential of arsenic-contg. amorphous selenium and is free from printing faults such as degraded printing density, fogging and degraded resolution by using the styrene/acrylic binder resin for toners which is produced by suspension polymn. and contains a residual inorg. dispersant at a specific value or above. CONSTITUTION:The toner for developing electrostatic charge images formed by incorporating the styrene/acryl binder resin for toners which is produced by suspension polymn. and contains the residual inorg. dispersant at <=3,000ppm, the magnetic toner and the two-component developer are used. The printing faults such as degraded printing density, fogging and degraded resolution are prevented over a long period of time in this way by the combination of such toner and a photosensitive body consisting of the arsenic-contg. amorphous selenium. An always good image is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a binder resin for toner, a toner and developer for developing electrostatic images using the same, and an image forming method using the same.

(Prior Art) As described in US Pat. No. 229.769, British Pat. A charging process that uses a conductive substance to apply an electrostatic charge to the photoreceptor; an exposure process that irradiates light to form an electrostatic latent image;
A developing process in which toner is attached to the latent image area, a transfer process in which the toner material is transferred to an image supporting material such as paper as necessary, and a fixing process in which the toner material is attached to the image supporting material using heat, pressure, flash light, etc.

This process consists of a cleaning process for removing toner remaining on the photoconductor, and a discharging process for removing static charges on the photoconductor and returning it to its initial state.

Toners used in electrophotography include toners using polystyrene resin (Japanese Patent Publication No. 16118/1983), toners using styrene/butyl methacrylate copolymer resin (Japanese Patent Publication No. 11143/1981), and bisphenol type toners. Toner using Evokin resin (Japanese Patent Laid-Open No. 57-96
354), toners using a polyester resin obtained by reacting a glycol having a bisphenol skeleton with a polybasic acid (Japanese Patent Publication No. 52-25420), and 9% Japanese Publication No. 56-11143. The styrene/acrylic resin described in the publication can control resin physical properties such as molecular weight, glass transition temperature, and melt viscosity over a wide range compared to other resins, and is extremely advantageous in toner design. The majority of this is made up of styrene/acrylic resin.

Styrene/acrylic resins can be manufactured using known methods such as suspension polymerization, solution polymerization, bulk polymerization, and emulsion polymerization, but suspension polymerization requires less solvent than other polymerization methods. Do not use 9. It has many advantages such as easy reaction control and easy separation of polymerized products, and is suitable for producing styrene-acrylic resin for toner.

Dispersants used in suspension polymerization include barium sulfate, calcium carbonate, and tricalcium phosphate.

With inorganic dispersants that are poorly soluble in water, such as hydroxide phosphate.

Starch, methylcellulose, polyvinyl alcohol.

It can be broadly divided into water-soluble organic dispersants such as polyacrylic acid, but threads using inorganic dispersants as the dispersant allow for smooth separation of the polymer from the suspension, and also facilitate drying in the subsequent process. It has the following characteristics.

In recent years, there has been a remarkable shift in photoconductive materials from zinc oxide, cadmium sulfide, and amorphous selenium to arsenic-containing amorphous selenium, which has excellent sensitivity, wavelength spectral characteristics, crystallization resistance, hardness, etc.

(Problems to be Solved by the Invention) A latent image is formed on arsenic-containing amorphous selenium through a charging and exposure process, and toner is attached to the latent image portion to make it visible. However, when the latent image of arsenic-containing amorphous selenium is repeatedly visualized with a toner containing styrene/acrylic resin produced by suspension polymerization using the above-mentioned inorganic dispersant, the charging process The charging potential of the arsenic-containing amorphous selenium decreased, and as a result, phenomena such as a decrease in print density, toner scattering to the background of the print (hereinafter referred to as fog), and a decrease in resolution were likely to occur.

The present invention solves the above-mentioned problems, and provides a toner that does not cause a decrease in the charging potential of arsenic-containing amorphous selenium even after repeated use over a long period of time, and does not cause printing problems such as a decrease in print density, fogging, or a decrease in resolution. The object of the present invention is to provide a useful binder resin, a toner or developer using the same, and an image forming method using the same.

(11! Means for Solving the Problem) The present invention provides a styrene-acrylic binder resin for toner that is produced by suspension polymerization and has a residual inorganic dispersant content of 300 ppm or less. The present invention relates to an electrostatic image developing toner, a magnetic toner and a two-component developer, and an image forming method characterized by using these toners or developers.

In the present invention, the inorganic dispersants used for suspension polymerization of the binder resin for toner include barium sulfate, calcium sulfate,
Calcium carbonate, barium carbonate.

Magnesium carbonate, tricalcium phosphate, calcium phosphate, hydroxide phosphate, Merck, bentonite, diatomaceous earth, clay rings, and inorganic substances that are poorly soluble in water.

Conventionally known materials can be used. Among them, tricalcium phosphate, calcium phosphate, and hydroxide phosphate have excellent dispersion ability and can be preferably used.

The amounts used are based on it of the polymerizable monomer.

It is preferable that the weight value of IX is 10-2 to 5.

In addition, as dispersion aids, alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, alkylsulfonates with 80sNa directly bonded to the alkyl group, and amides such as β-tetrahydronaphthalenesulfone im+ N-isopropylcyclohexy and sodium amidosulfonate are used. Anionic surfactants such as higher fatty acid salts such as sulfonate, oleic acid, etc. can be used as a substitute for the above-mentioned dispersant.

The dispersion aid is 1x10 based on the total amount of polymerizable monomers.
-4 to 0.01% by weight is preferred.

The content of the inorganic dispersant in the binder resin for toner in the present invention needs to be controlled to 3000 ppm or less per 1 fif of the binder resin. Preferably it is 2000 ppm or less, more preferably 1000 ppm or less. If the content of inorganic dispersant exceeds 3000 ppm,
Arsenic-containing amorphous selenium band'Fi in repeated use
The drop in the n-position is significant and two types of printing failures occur. Note that the remaining inorganic dispersant in the present invention can be quantitatively determined using an atomic absorption spectrophotometer.

To adjust the FA of inorganic dispersant to 3000 ppm or less.

For example, there is the following method.

The polymerized suspension was filtered to remove 9 polymers. Next, the polymer is preferably washed with an aqueous hydrochloric acid solution with a pH of 1 to 4 or an aqueous solution with a low pH.

Repeat washing. Furthermore, the effect will be greater if the polymer is crushed and washed.

Styrene/acrylic toner rigidity Mm in the present invention
The fat is a copolymer containing styrene or a derivative thereof and a derivative of acrylic acid or methacrylic acid as essential components. Examples of the polymerizable monomers used are shown below.

(11 styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2.
4-dimethylstyrene, p-n-butylstyrene, p-
tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-f silstyrene, p-n-dodecylstyrene, n-methoxystyrene, p-phenylstyrene ,p-
Styrene and its derivatives such as chlorstyrene and λ4-dichlorostyrene.

(2) Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodenyl acrylate,
2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate,
Methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodeffur methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, phenyl methacrylate, acrylonitrile, methacrylonitrile, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate.

2-Hydroxy7ethyl methacrylate, 2-hydroxy methacrylate
Acrylic acid or methacrylic acid derivatives such as hydroxypropyl.

(3) Dimethylamine methyl acrylate, dimethylaminoethyl acrylate, dimethylamine propyl acrylate, dimethylaminomethyl methacrylate,
dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates such as dimethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, aminoalkyl acrylates and aminoalkyl methacrylates such as aminomethyl acrylate, aminoethyl acrylate, aminomethyl methacrylate, aminoethyl methacrylate, morpholinomethyl acrylate, Morpholinoethyl acrylate, 2-morpholinopropyl acrylate.

3-morpholinopropyl acrylate, 2-morpholinopropyl acrylate, 4-morpholinobutyl acrylate, 3-morpholinobutyl acrylate, 2-
Morpholinoalkyl acrylates such as morpholinobutyl acrylate, 2-morpholinopentyl acrylate, 2-morpholinohexyl acrylate, and 2-morpholinooctyl acrylate, methacrylates having morpholinoalkyl similar to these, morpholino groups in morpholinoalkyl acrylates such as those exemplified above. aziridyl alkyl acrylate to which an aziridyl group, piperazyl group or piperidyl group is attached instead,
Piperadyl alkyl acrylates and piperidyl alkyl acrylates, aziridyl alkyl methacrylates having similar alkyl groups thereto, piperidyl alkyl methacrylates and piperidyl alkyl methacrylates.

Morpholinoethyl acrylamide, morpholinomethyl acrylamide, 3-morpholinopropylacrylamide, 2-morpholinopropylacrylamide, 4-morpholinobutylacrylamide.

3-morpholinobutylacrylamide, 2-morpholinobutylacrylamide, 2-morpholinopentylacrylamide, 2-morpholinohexylacrylamide, 2
- Morpholinoalkyl acrylamides such as morpholinooctylacrylamide.

Morpholinoalkylmethacrylamide having a morpholinoalkyl group similar to these, aziridylalkylacrylamide, piperazyl, in which an aziridyl group, piperazyl group or piperidyl group is bonded instead of two morpholino groups in the morpholinoalkylacrylamide shown above. Alkylacrylamides and piperidylalkylacrylamides, aziridylalkylmethacrylamides having similar alkyl groups, piperidylalkylmethacrylamides and piperidylalkylmethacrylamides, morpholinomethylthioacrylate, morpholinobutylthioacrylate, 3-morpholinopropylthioacrylate , 2-Solfolinoprobyl thioacrylate.

, 4-morpholinobutylthioacrylate), 3-morpholinobutylthioacrylate, 2-morpholinobutylthioacrylate, 2-morpholinopentylthioacrylate, 2-morpholinohexylthioacrylate, 2-
Morpholinoalkylthioacrylates such as morpholinooctylthioacrylate, and morpholinoalkylthiomethacrylates having similar morpholinoalkyl groups.

In the morpholinoalkylthioacrylate as exemplified above, an aziridyl group instead of the 2 morpholino group,
Aziridyl alkylthioacrylate, piperadylalkylthioacrylate and piperidylalkylthioacrylate to which a piperazyl group or a piperidyl group is bonded, aziridylalkylthiomethacrylate having an alkyl group similar to these, piperidylalkylthiomethacrylate and piperidylalkylthiomethacrylate containing an amino group Addition polymerizable monomer.

(4) Acrylic acid, methacrylic acid, maleic acid.

Carboxyl group-containing addition polymerizable monomers such as fumaric acid and itaconic acid, and their sodium salts.

Metal salts such as potassium salts and zinc salts.

(51p-styrenesulfonic acid, 0-methylstyrenesulfonic acid, 1m-methylstyrenesulfonic acid.

Styrene sulfonic acids such as chlorstyrene sulfonic acid,
Acrylic or methacrylic alkylsulfonic acids such as methylsulfonic acrylate, ethylsulfonic acrylate, propylsulfonic acrylate, methylsulfonic methacrylate, ethylsulfonic methacrylate, propylsulfonic methacrylate, and their sodium salts , potassium salts, zinc salts, and other metal salts.

(6) Ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and inbutylene.

f71 Vinyl mide, vinylidene chloride, vinyl bromide.

Vinyl halides such as vinyl fluoride, vinyl acetate.

Vinyl esters such as vinyl propionate, vinyl penzoate, and vinyl butyrate.

(8) Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether.

(91 Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, etc.)

(10) N such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone, etc.
- Vinyl compounds.

(11) Vinylnaphthalene salt, etc.

In particular, styrene/acrylic resin is used in the present invention.

(a) 40 to 85% by weight of styrene or styrene derivative (preferably styrene), (the number of carbon atoms in the bl alkyl group is 3
~22 acrylic acid alkyl esters and/or methacrylic acid alkyl esters 15 to 60 deuterium i-1, (C
) Other copolymerizable monomers (0 to 40% by weight), which is obtained by blending components (a) to (C1) so that the total amount is 100% by weight, and copolymerizing them. Blocking resistance required for toner (blocking: a phenomenon in which toner particles aggregate and form clumps) Excellent properties such as fixation properties are preferred.

In the present invention, aqueous 1 [Polymerization initiators used in the polymerization method include peroxides such as benzoyl peroxide and tert-butyl perbenzoate, azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile, etc. The amount of oil-soluble polymerization initiator is preferably 0 per total polymerizable monomer.
．． 1-2.0% by weight.

Particularly preferably, 0.1 to 101 i is used.

The molecular weight of the resin can be adjusted by appropriately selecting the type and amount of the polymerization initiator and the temperature during the polymerization reaction.

Examples of chain transfer agents include alkyl mercaptans such as t-dodecyl mercaptan, lower alkyl xanthogens such as diisopropyl xanthogen, carbon tetrachloride, carbon tetrabromide, etc., and the amount is O to 2 i% based on the dipolymerizable monomer. Preferably used.

Although the above styrene/acrylic resin is the main component of the binder resin of the present invention, other binder resins can also be used in combination. Such binder resins include styrene resin, acrylic resin, silicone resin, polyester carbonate resin,
Xylene resins, epoxy resins, phenol resins, diene resins, coumaron resins, amide resins, amino resins, urethane resins, and other known resins may be used within a range that does not impair the characteristics of the present invention (preferably 30% by weight of the total binder resin). (below) can be used.

Colorants used in the production of toners and developers of the present invention may include pigments or dyes. For example, carbon black, nigrosine dye (C, I, N
a50415), aniline blue (C,1,N1150
405), Calco Oil Blue (C.

I, Nll azoec Blue 3) * Chrome Ye 0-(C, I.

14090), Ultramarine Blue (C, 1, Koji 7)
7103), DuPont oil let C0■, Nl12
6105), Orient Oil Red ÷ 330 (C, I
,! 4I160505), quinoline yellow (C
,I.

k47005), methylene blue chloride (C.

■, MA52015), Phthalocyanine Blue (C, I.

Na74160), malachite green oxalay)
(C, 1, Magic 42000), Lamp Black (C,
I.

Nn77266), O's Bengal (C11,ll!Q
45435), oil black, azo oil black, etc. can be used alone or in combination. These colorants can be used in any amount, but preferably 1 is added to the total toner components to obtain the required concentration.
It is used in a proportion of ~30% by weight, particularly preferably from 5 to 15% by weight.

Magnetic powder is used when producing the magnetic toner of the present invention, and can also serve as a colorant.

Preferred magnetic powders include oxides or compounds of iron such as magnetite or ferrite, or ferromagnetic elements such as nickel and cobalt. These magnetic powders are preferably in powder form with a particle size of 0.01 to 3 μm, and even if the surface of the magnetic powder is treated with a resin, a titanium coupling agent, a 7-run coupling agent, a higher fatty acid metal salt, etc. good. These magnetic powders are preferably used in an amount of -CIE or 20 to 80% by weight, particularly preferably 35 to 70% by weight, based on the total toner components. It may be used as an N coloring agent in an amount less than this, or may be used in combination with an N coloring agent.

An offset inhibitor is used as necessary.

Various natural waxes as anti-offset agents.

For example, carnauba wax, hydrogenated castor oil, or low molecular weight olefin polymers can be used in the present invention, and preferably low molecular weight olefin polymers are used. As this low molecular weight olefin polymer, a low molecular weight polymer of olefin or a copolymer of an olefin and a monomer other than olefin is used. Here, olefins include ethylene, propylene, butene-1, etc., and monomers other than olefins include acrylic esters.

Examples include methacrylic acid esters. Examples of this low molecular weight olefin polymer include 2, for example, JP-A No. 55-153944;
The polyalkylene described in the publication, JP-A-50-
Low molecular weight olefin copolymers described in Japanese Patent No. 93647 can be used.

The molecular weight of the low-molecular-weight olefin polymer used in the toner and developer of the present invention may be within the concept of low-molecular weight as commonly referred to as a high-molecular compound.

Generally, weight average molecular t (Mw) 1,000 to 45
,000° preferably 2. ooo~6.000.

The low molecular weight olefin polymer that can be used in the toner and developer of the present invention preferably has a softening point of 100 to 180°C, particularly 130 to 160°C.

There is no particular limit to the amount of the low molecular weight olefin polymer that can be used in the toner and developer of the present invention, but it is preferably in the range of 0 to 30% by weight, particularly preferably 1 to 10% by weight based on the total amount of the toner. 1 inch heavy is used. If the amount of low molecular weight olefin polymer is too small, the anti-offset effect will not be achieved by adding it, and if it is too large, the fluidity and
Blocking resistance deteriorates. Furthermore, a fluidity improver, a cleaning property improver, etc. can be used as necessary.

Although these can be added during toner production, they are preferably externally added to the finished toner afterwards.

The content of each of these is 0 for the toner of the present invention.
~3% by weight is preferred. For fluidity improvers.

There are oxides of silane, titanium, aluminum, calcium, magnesium, and magnesium, or those obtained by hydrophobizing the above oxides with a titanium coupling agent or a silane coupling agent. Cleanability improvers include zinc stearate and lithium stearate. and metal salts of higher fatty acids such as magnesium laurate or aromatic α-esters such as pentaerythritol benzoate.

In the present invention, obi 1! A charge control agent can also be used in the toner and developer of the present invention in order to adjust the amount and charge polarity to desired values.

The charge control agent preferably used in the toner and developer of the present invention is alcohol soluble nigrosine dye.

Nigrosine dyes such as fatty acid-modified nigrosine dyes and carboxyl group-containing resin-modified nigrosine dyes, Subiron Black T RH, Subiron Black TPH Hodogaya Chemical Industry #
Azo dyes such as 1[), p-fluorobenzoic acid, p-nitrobenzoic acid, aromatic acid derivatives such as 2,4-di-monophylsalicylic acid, tin compounds such as dibutyl-tin oxide, dioctyl-tin oxide, etc. can be mentioned.

These are preferably used in a 0 to 5-fold sweetening manner with respect to the polymerizable monomer.

When the toner obtained in this way is used as a two-component developer, iron oxide powder of various shapes such as flat, cavernous, coin-shaped, true spherical, etc., manganese, cobalt, nickel, zinc, ferrite such as tin, magnesium, lead, strontium, barium, lithium, Teflon resin, acrylic resin, polyester resin, silicone resin,
Iron oxide powder and ferrite whose surface is coated with melamine resin, butadiene resin, butyral resin, etc.

It can be used in combination with carriers such as particles made of mixtures of various resins and magnetic powders.

The toner concentration of a two-component developer generally depends on the specific surface area of the carrier, and when the carrier used is amorphous or has a fine particle size, the amount is 3 to 10M, and when the carrier is spherical or has a coarse particle size, it is 1 to 10M. It is preferable to make it 5 weight i%.

The magnetic toner or two-component developer obtained as described above is particularly suitable for an image forming method in which an electrostatic latent image formed on an arsenic-containing amorphous selenium photoreceptor is visualized.
Even when used continuously for a long time, good images can always be obtained.

The present invention is applicable to various development processes, such as U.S. Pat.
18,552, the magnetic brush method described in U.S. Patent No. 2,874,065, the powder cloud method described in U.S. Patent No. 4221.776, U.S. Pat. Cylinder 3,166.43
Touchdown development method described in No. 2, JP-A-55-186
It is described in Publication No. 56. In the so-called jumping method, a magnetic toner produced by a pulverization method is used as a carrier.

The necessary toner charge is obtained by a so-called microtoning method and frictional charging between magnetic toners.

It can be used in so-called bipolar magnetic method.

Furthermore, the present invention can be used in various fixing methods 9 such as so-called oil-less and oil-coated heat roll methods, flash methods, open methods, pressure fixing methods, and the like.

Furthermore, the present invention can be used in various cleaning methods such as the so-called fur brush method and blade method.

(Example) The present invention will be explained in detail below.

Example 1 70 parts by weight of styrene and 30 parts by weight of butyl methacrylate were mixed into 1M initiator using 4 parts by weight of benzoyl peroxide.
g in 200M parts of an aqueous solution containing 0.4 parts by weight of hydroxide phosphorite as a dispersant! Turbid polymerization occurred. The obtained resin has a pH of 2
After washing twice with an aqueous hydrochloric acid solution, in order to remove residual hydrochloric acid, the sample was washed with water (pH 7) until the pH reached 7, and then dried. Then, the powder was ground to a particle size of about 100 μm, washed twice with the above hydrochloric acid aqueous solution, further washed with water until the pH reached 7, and dried. The amount of remaining hydroxide phosphorite measured with an atomic absorption spectrophotometer (z-sooo, manufactured by Hitachi Seisakusho) (the same applies to the following Examples and Comparative Examples) was 500 ppln.

86.5 parts by weight of the above binder resin, 1.6 parts by weight of fatty acid-modified nigrosine dye (Oil Black BY, manufactured by Orient Chemical Industry Co., Ltd.) as a positive charge control agent, and 1.6 parts by weight of a fatty acid-modified nigrosine dye (Oil Black SO, manufactured by Orient Chemical Industry Co., Ltd.) containing a carboxyl group-containing resin (Oil Black SO, manufactured by Orient Chemical Industry Co., Ltd.) 9 parts by weight of carbon black (Carbon Black 44, manufactured by Mitsubishi Chemical Industries Ltd.) as a coloring agent, 1 part by weight of 7.5 parts of carbon black (manufactured by Mitsubishi Chemical Corporation), an olefin polymer (Viscol 550P, Sanyo Chemical Co., Ltd.) as an offset inhibitor Industrial ■) 2
Parts by weight were melt-kneaded, pulverized and classified to produce a positively chargeable toner with a diameter of 2 to 25 μm.

2-5 parts by weight of the toner and a flat iron oxide powder carrier 97
．． A two-component developer consisting of 5 parts by weight was prepared.

Therefore, an arsenic-containing amorphous selenium photoconductor rotating at a circumferential speed of about 30 cm/sec was uniformly positively charged to a surface potential of about 600 V with a corona voltage of +5.5 kV, and information was written using a He-Ne laser. Reversal development was performed using the developer using a magnetic brush method. Next, the toner image was transferred to continuous paper and fixed using a pressurized heat roll fixing device, which continued for 20 hours while replenishing toner. It was positively charged and good images were always obtained.

Example 2 6011 parts of styrene, 25 parts by weight of 2-hydroxyfurovir methacrylate and 1 site part of butyl acrylate; 4 parts by weight of azobisisobutyronitrile as a polymerization initiator; 2 3 parts by weight of calcium carbonate as a dispersant; Suspension polymerization was carried out in 200 parts by weight of an aqueous solution containing. The obtained resin was adjusted to PH2
Wash with an aqueous solution of hydrochloric acid, further wash with water until the pH reaches 7, and dry.

Thereafter, it was ground to about 100 μm using a hammer mill.

After washing again with a pH2 hydrochloric acid aqueous solution, the pH was further washed with water.
It was washed and dried until it reached 7. The amount of calcium carbonate remaining was 1000 ppm.

87 parts by weight of the above binder resin, 3 parts by weight of dibutyltin oxide as a positive charge control agent, 9 parts by weight of carbon black (carbon black φ33, manufactured by Mitsubishi Chemical Corporation) as a coloring agent, and an olefin polymer as an offset inhibitor. (Himer 330P, manufactured by Sanyo Kasei Kogyo ■) 3 parts by weight were melt-kneaded, pulverized and classified into 2 parts to produce a positively chargeable toner with a diameter of 5 to 25 μm.

3 parts by weight of the toner and a substantially spherical iron oxide powder carrier 9
A two-component developer consisting of 7 parts by weight was prepared.

Therefore, an arsenic-containing selenium photoreceptor rotating at a circumferential speed of about 30 cm/sec was uniformly positively charged to a surface potential of about 600 V with a corona voltage of +5.5 kV, information was written using a He-Ne laser, and this was transferred to the developer. Reversal development was carried out using a magnetic brush method. Next, the toner image was transferred to continuous paper and fixed using a pressurized heat roll fixing device, which was continued for 20 hours while replenishing toner. By the end, the surface potential of the arsenic-containing amorphous selenium photoconductor was approximately 600V. Positive Vf current was applied, and good images were always obtained.

Example 3 The copolymer 89 heavy part used in Example 1, the chromium complex of an azo compound (Bontron 8-31, manufactured by Orient Chemical Industry @) 31 part, which is a negative charge control agent.

Carbon black (Carbon Black 4) is a coloring agent.
4) 7 parts by weight and 111 parts of an olefin polymer (Viscol 5soP) as an offset inhibitor were melt-kneaded, pulverized, and classified into two to produce a negatively chargeable toner with a size of 5 to 30 μm.

5 parts by weight of the toner and carrier 95i used in Example 1
A two-component developer consisting of 3 parts was prepared.

Therefore, an arsenic-containing selenium photoconductor rotating at a circumferential speed of about 30 cm/sec was uniformly positively charged with a corona voltage of +5.5 kV to a surface potential of about 600 V, information was written using a He-Ne laser, and this was subjected to the development described above. Regular development was carried out with a chemical agent.

Next, the toner image was transferred to continuous paper and fixed using a pressurized heat roll fixing device, which was continued for 20 hours while replenishing toner. By the end, the surface potential of the arsenic-containing amorphous selenium photoconductor was approximately 600 ■. It was positively charged, and good images were always obtained.

Example 4 An aqueous solution containing 80 parts by weight of styrene and 20 parts by weight of butyl acrylate as a polymerization initiator, 3 parts by weight of benzoyl peroxide as a dispersant, and 1 part of tricalcium phosphate as a dispersant.
Suspension polymerization was carried out in 0 parts by weight.

After washing the obtained resin with an aqueous hydrochloric acid solution of PH2.

In order to remove residual hydrochloric acid, it was washed with water until the pH reached 7 and dried. Next, grind it with a hummer mill, 10
After washing with the above-mentioned hydrochloric acid aqueous solution again, washing with water until the pH reached 7 and drying was carried out. The amount of remaining tricalcium phosphate was 10,001) pm.

53 parts by weight of the above-mentioned binder resin, chromium complex (Spiron Black TRH, manufactured by Hodogaya Chemical Industry ■) as a negative charge control agent 2
i part, magnetic powder (magnetite with an average particle size of 0.5 μm)
45 parts by weight were melt-kneaded.

The powder was pulverized and classified into 9 classes to produce a negatively charged magnetic toner having a size of 5 to 35 μm.

The magnetic toner 1001 has 0 hydrophobic colloidal calcium.
．． 5 parts by weight were added and mixed to prepare a developer.

Therefore, an arsenic-containing selenium photoreceptor rotating at a circumferential speed of about 8 km/sec was uniformly positively charged with a corona voltage of +6 kV to a surface potential of about 700 V, and then information was written using a fluorescent lamp.

This was regularly developed using the developer described above. Next, the toner image was transferred to paper and fixed using a pressurized heat roll fixing device, which was continued for 20 hours while replenishing toner.
Until the end, the arsenic-containing amorphous selenium photoreceptor has a surface potential of approximately 7.
It was positively charged to 00V, and good image quality was always obtained.

Comparative Example 1 An aqueous solution containing 70 parts by weight of styrene, 30 parts by weight of butyl methacrylate, 4 parts by weight of benzoyl peroxide as a polymerization initiator, and 0.4 parts by weight of hydroxide phosphate as a dispersant.
The resin obtained by suspension polymerization in 0.1 fit part was dried. The residual phosphorus hydroxide content was 3200 ppm.

86.5 parts by weight of the above resin, 1.6 parts by weight of fatty acid-modified nigrosine dye (Oil Black BY) as a positive charge control agent, and 4 parts by weight of carboxyl group-containing resin-modified nigrosine dye (Oil Black 80)'.

Carbon black (Carbon Black 4) is a coloring agent.
4) Melt and knead 7.5 parts by weight and 2 parts by weight of an olefin polymer (Viscol 550P) as an offset inhibitor,
The powder was crushed and classified into two to produce a positively chargeable toner having a particle size of 5 to 25 μn1.

25 parts by weight of the toner and 97 parts by weight of flat iron oxide powder carrier.
A two-component developer consisting of 5 parts by weight was prepared.

Therefore, an arsenic-containing amorphous selenium photoconductor rotating at a circumferential speed of about 30 cm/sec was uniformly positively charged to a surface potential of about 600 V with a corona voltage of +5.5 kV, and then information was scanned with a He Ne laser. Reversal development was performed using the developer using a magnetic brush method. Next, transfer the toner image to continuous paper,
When fixing was continued for 20 hours using a pressurized heat roll fixing device while replenishing toner, the surface potential of the photoconductor gradually decreased, and finally the arsenic-containing selenium photoconductor reached a corona voltage of +5.5 kV. The surface potential was only positively charged to about 350V. The obtained image had fog over the entire surface.

Comparative Example 2 Using 80 parts by weight of styrene and 20 parts by weight of butyl acrylate as a polymerization initiator and using benzoyl peroxide 3 * * @2
Suspension polymerization was carried out in 200 parts by weight of an aqueous solution containing 1 part by weight of tricalcium phosphate as a dispersant.

The obtained resin was washed with an aqueous hydrochloric acid solution with a pH of 2, and the pH was adjusted to 7 with water.
Washed and dried until clean. The amount of residual tricalcium phosphate was sooo ppm.

53 parts by weight of the above resin, 2fL parts of chromium complex (Subiron black 'rI'LH) which is a negative charge control agent, and 45 parts by weight of magnetic powder (magnetite with an average particle size of 0.5 μm) were melt-kneaded and pulverized. The mixture was classified into 9 parts to produce a negatively charged magnetic toner having a size of 5 to 35 μm.

0.5 parts by weight of hydrophobic silica was added to 100 parts by weight of this magnetic toner and mixed to prepare a developer.

Therefore, an arsenic-containing amorphous selenium photoconductor rotating at a circumferential speed of about 8 cm/sec was uniformly positively charged to a surface potential of about 700 cm with a corona voltage +6) clY, information was written using a fluorescent lamp, and this was Regular development was performed using a developer. Next, the toner image was transferred to two sheets of paper and fixed using a pressurized heat roll fixing device, which was continued for 20 hours while replenishing the toner.The surface potential of the photoreceptor gradually decreased, and finally the arsenic-free image was transferred. The regular selenium photoreceptor has a surface potential of approximately 4 at a corona voltage of +6 kV.
It was positively charged only to 50V. The obtained image had fog over the entire surface.

(Effects of the Invention) As is clear from the above results, according to the present invention, in combination with an arsenic-containing amorphous selenium photoreceptor, printing density decreases and fogging occurs over a long period of time.

It is possible to obtain a toner binder resin, toner, and developer that can prevent printing problems such as a decrease in resolution.

Furthermore, there is an image forming method using a combination of these and an arsenic-containing amorphous selenium photoreceptor.

Particularly good images can be obtained.

Claims (1)

[Scope of Claims] 1. A styrene-acrylic binder resin for toner, which is produced by suspension polymerization and has a residual inorganic dispersant content of 3000 ppm or less. 2. A toner for developing an electrostatic image, comprising the toner binder resin according to claim 1. 3. A magnetic toner for developing electrostatic images, comprising the toner binder resin according to claim 1 and magnetic powder. 4. A two-component developer comprising the toner according to claim 2 and a carrier. 5. After forming an electrostatic latent image on the arsenic-containing amorphous selenium photoreceptor, the electrostatic latent image is brought into contact with the magnetic toner according to claim 3 or the two-component developer according to claim 4 to be developed. An image forming method characterized by imaging.