JPH04181950A - Electrostatic charge developing toner and production thereof - Google Patents

Abstract

PURPOSE:To improve moisture resistance and to improve triboelectrostatic chargeability and charge controllability as well by specifying the contact angle of the surface of the molding obd. by compression molding of a toner against water to >=60 deg.. CONSTITUTION:This electrostatic charge image developing toner contains the resin fine particles which are obtd. by a suspension polymn. method using a dispersion stabilizer consisting of hardly water-soluble inorg. fine powder and contain a water-soluble monomer and an oil-soluble monomer as constituting components and on the surface of which the copolymer of the water-soluble monomer and the oil-solble monomer exists. The contact angle of the surface of the molding obtd. by compression molding of such toner against water is >=60 deg.. The electrostatic charge image developing toner which has the higher moisture resistance than heretofore and is excellent in both the triboelectrostatic chargeability and charge controllability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrostatic image developing toner obtained by suspension polymerization used in image forming apparatuses such as electrophotography, and a method for producing the toner.

<Prior Art> In a method for manufacturing toner used in image forming apparatuses such as electrophotography, it is important for the toner to have a certain triboelectric chargeability and charge controllability in order to form excellent images. be. For example, even if the toner has a predetermined amount of charge due to frictional charging, if toner with different charge polarity is present on multiple plates, toner scattering and background fogging may occur during image formation, and the image density may change. This will lead to a decrease in resolution, etc.

Therefore, the present applicant proposed an invention relating to a toner having a predetermined charge control property in Japanese Patent Laid-Open No. 193748/1999. In detail, this invention includes an oil-soluble monomer,
A polymerizable composition consisting of a polymerization initiator soluble in this, a coloring agent, etc. is suspended in an aqueous solution containing a water-soluble dispersion stabilizer by high-speed stirring to prepare suspended particles. By adding a water-soluble monomer having a charge-controlling functional group to the suspension and performing radical polymerization in the presence of a polymerization initiator, the water-soluble monomer reacts with the surface of the suspended particles, resulting in water-soluble Toner fine particles are obtained in which a copolymer of a monomer and an oil-soluble monomer is present on the surface.

(Problems to be Solved by the Invention) However, in such suspension polymerization, a water-soluble dispersion stabilizer is used to stably suspend water-insoluble monomers in an aqueous medium. Since the dispersion stabilizer is attached to the surface of the toner fine particles, there are disadvantages in that the frt wettability is poor and the electrical characteristics are likely to deteriorate, and the charging property is also insufficient.

It is also possible to use a poorly water-soluble dispersion stabilizer as a dispersion stabilizer, but in this case, in order for the dispersant to coat the surface of the suspended particles, the oil-soluble monomers constituting the suspended particles This has the drawback that the reaction between the water-soluble monomer and the water-soluble monomer is inhibited, and the water-soluble monomer does not polymerize, resulting in a decrease in charge controllability of the toner.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and its purpose is to provide a toner for developing electrostatic images that has excellent moisture resistance, triboelectric charging properties, and charge control properties, and its purpose. The purpose is to provide a manufacturing method.

(Means for Solving the Problems) The toner for developing electrostatic images of the present invention is obtained by a suspension polymerization method using a dispersion stabilizer made of a poorly water-soluble inorganic fine powder, and is made of a water-soluble monomer and A toner for developing an electrostatic image, comprising resin fine particles having an oil-soluble monomer as a constituent component and having a copolymer of a water-soluble monomer and an oil-soluble monomer on the surface, the toner comprising: The contact angle between the surface of the molded product obtained by compression molding and water is 60° or more, thereby achieving the above object.

In the method for producing a toner for developing electrostatic images of the present invention, suspended particles are prepared by suspending an oil-soluble monomer in an aqueous medium using a dispersion stabilizer made of a poorly water-soluble inorganic fine powder. a step of polymerizing the oil-soluble monomer in the suspended particles until the conversion rate of the oil-soluble monomer reaches a predetermined range; and a step of polymerizing the oil-soluble monomer in the suspended particles until the conversion rate of the oil-soluble monomer falls within the predetermined range. The dispersion stabilizer is dissolved by changing the dispersion stabilizer, and the water-soluble monomer present in the aqueous medium and the oil-soluble monomer of the suspended particles are reacted to produce resin fine particles. This achieves the above objective.

(Function) When the conversion rate of the oil-soluble monomer falls within a predetermined range, the dispersion stabilizer is dissolved by changing the pH of the aqueous medium,
By reacting the water-soluble monomer present in the aqueous medium with the oil-soluble monomer on the surface of the suspended particles, the suspended particles are formed while forming suspended particles having a particle size within a predetermined range. By copolymerizing an oil-soluble monomer and a water-soluble monomer, a copolymer containing the water-soluble monomer as a copolymerization component can be distributed on the particle surface. According to this method, since a poorly water-soluble dispersion stabilizer for the oil-soluble monomer is used, a toner with excellent moisture resistance can be obtained.

If the dispersion stabilizer is dissolved by changing the pH of the aqueous medium when the conversion rate of the suspended particles does not reach a predetermined range, the suspended particles may become sticky with each other due to their strong adhesion. tends to aggregate, and if the pH of the aqueous medium is changed to dissolve the dispersion stabilizer when the conversion rate of suspended particles exceeds a predetermined range, it may react with the water-soluble monomer. Since the remaining amount of the oil-soluble monomer is small, it is difficult for the water-soluble monomer to be introduced onto the surface of the suspended particles.

The above-mentioned conversion rate of the oil-soluble monomer within a predetermined range means a value expressed as a ratio of the amount of polymer produced to the amount of monomer charged. The water-soluble monomer in an amount such that the copolymer with the water-soluble monomer effectively imparts properties to the toner particles based on the conversion rate when the suspended particles are no longer fused to each other due to the dissolution and removal of the stabilizer. This is the range of the conversion rate when an amount of oil-soluble monomer that can react with the oil-soluble monomer remains in the suspended particles. This range varies depending on the resin composition used, the type of dispersion stabilizer, the pH of the aqueous medium, etc.
Usually it is 80-97%.

Further, the toner of the present invention is obtained by the above-mentioned suspension polymerization method, and has a contact angle θ of 60° or more between the surface of a molded product obtained by compression molding the toner and water.

Here, the contact angle θ is defined by the following formula from the measured values of the advancing contact angle θa and the receding contact angle θr between water (distilled water) and the plane of a pellet-shaped sample obtained by compression molding the toner. be done.

cos θ=1/2 (cos θa+cos θr) The compression molding conditions for the above toner are 6 to 10 kg/cm 2 .

Conventionally, when a toner is produced by suspension polymerization using a water-soluble dispersion stabilizer, a toner with a contact angle θ of less than 60° is obtained, and such a toner has poor moisture resistance. , the charging property decreases. In the present invention, a particularly preferable contact angle θ is 62 to 8o0.

(Preferred embodiment of the invention) Preferred embodiments of the present invention will be explained in detail below.

In the description of the present invention, the present invention will be broadly classified into raw materials for resin particles constituting the toner and toner polymerization methods. The explanation will be given below in order.

(a) Oil-soluble monomer The oil-soluble monomer used in the present invention is capable of forming a thermoplastic resin having fixing properties and electrodetection properties. Examples of monomers include monovinyl aromatic monomers, acrylic monomers, vinyl ester monomers, vinyl ether monomers, diolefin monomers, and monoolefin monomers.

These monomers may be used alone or in combination of two or more.

As the monovinyl aromatic 14311 body, those whose general formula is represented by the following formula (1) are used, and specifically, styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, 0-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene, sodium styrene sulfonate, divinylbenzene,
These can be used alone or in combination of two or more.

In the formula, R1 represents a hydrogen atom, a lower alkyl group, or a halogen atom, and R2 represents a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amine group, a nido tetragroup, a vinyl group, or a carboxyl group.

As the above-mentioned acrylic monomer, those whose general formula is represented by the following formula (2) are used, and specifically, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid -2-ethyl to bovine sil, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, methacrylic acid to bovine sil, methacrylic acid-2
-Ethylhexyl, β-ethyl hydroxyl methacrylate, γ-propyl hydroxyacrylate, δ-butyl hydroxyl methacrylate, ethyl γ-amine acrylate, 7-N,N-diethylaminoacrylic acid Examples include propyl, ethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate, and these can be used alone or in combination of two or more.

RcoC)Iz"C-Co-0-Rt ,... In the formula (2), R3 represents a hydrogen atom or a lower alkyl group, and R4 represents a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, a hydrocarbon group having 1 to 12 carbon atoms, Indicates a bovine sial group, a vinyl ester group, or an aminoalkyl group.

The general formula of the above vinyl ester monomer is the following formula (
Those represented by 3) are used, and specific examples thereof include vinyl formate, vinyl acetate, vinyl propionate, and the like.

CH2=CH 0-C-R5...(3) In the formula, R5 represents a hydrogen atom or a lower alkyl group.

The general formula for the above vinyl ether-based it isomer is the following formula (
Those represented by 4) are used, specifically vinyl methyl ether, vinyl ethyl ether, vinyl-n-phthyl ether, vinyl phenyl ether, vinyl cyclohexyl ether and the like.

C) I2=CH o-R6・・・・・・(4) In the formula, R6 represents a hydrocarbon group having 1 to 12 carbon atoms.

The general formula of the above diolefin monomer is the following formula (5
) are used, specifically butadiene,
Examples include isoprene and chlorobrene.

In the formula, R7, R8, and R9 each independently represent a hydrogen atom, a lower alkyl group, or a halogen atom.

The general formula for the above monoolefin monomer is the following formula (
6) are used, specifically ethylene,
Propylene, imbutylene, butene-1, pentene-1
, 4-methylpentene-1, etc. are removed.

R1゜CL=C-R1 summer ・
・ ・ ・ ・ ・ In formula (6), R111% Each R port independently represents a hydrogen atom or a lower alkyl group.

(+)) Water-soluble monomer having a charge-controlling functional group This monomer may be an anionic group of the sulfonic acid, phosphoric acid, 7'J sulfonic acid type, or a primary, secondary, or tertiary amino group. radically polymerizable monomers having a charge control functional group such as a cationic group such as a group or a cationic group such as a quaternary ammonium salt;
An example is as follows.

Styrene sulfonic acid, sodium styrene sulfonate,
2-acrylamido 2-methylpropanesulfonic acid, 2
-Acid phosphooxypropyl methacrylate, 2-
Acid, dophosphobovine diethyl methacrylate, 3-chloro 2-acid phosphooxypropyl methacrylate,
Acrylic acid, methacrylic acid, fumaric acid, maleic acid, crotonic acid, tetrahydroterephthalic acid, itaconic acid, aminostyrene, amine ethyl methacrylate, aminopropyl acrylate, diethylaminopropylacrylate, γ-N-(N',N'-diethylamino ethyl)
Aminopropyl methacrylate, trimethylammonium propyl methacrylate%.

(c) Dispersion stabilizer The dispersion stabilizer used in the present invention is composed of a poorly water-soluble inorganic fine powder, and is used to stably disperse the oil-soluble monomer in an aqueous medium.

Examples of such dispersion stabilizers include calcium phosphate, calcium carbonate, calcium sulfate, magnesium carbonate, barium carbonate, aluminum hydroxide, and the like.

(d) Radical polymerization initiator A commonly known radical polymerization initiator can be used to produce the toner of the present invention. nitrile), 2,2°-azobisisobutyronitrile,
11'-azobis(cyclohexane-1-carbonitrile), 2.2°-azobis-4-methoxy-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvalero Azo compounds such as nitrile, 2,2-azobis(2-chlorobropionitrile),
Examples include peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, and lauroyl peroxide. In addition, combinations with ionizing radiation such as gamma rays and accelerated electron beams and various sensitizers are also used.

The amount of the polymerization initiator such as an azo compound or peroxide may be a so-called catalyst (2), and is generally 0.1 to 1 per monomer charged.
Preferably, it is used in an amount of 0% by weight.

(e) Colorant The toner of the present invention contains a colorant consisting of known dyes and pigments. Examples of colorants include the following.

■Black pigments carbon black, acetylene black, lambburasoku, aniline black.

■Yellow pigment yellow lead, zinc content, cadmium yellow, yellow iron oxide, mineral first yellow, nickel titanium yellow, pure yellow, naphthol yellow 81, banza yellow 10G, benzidine yellow 61, hand Norin yellow lake, permanent yellow NGG,
Tartrazine rake.

■Orange pigments red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, palkan orange, indanthrene brilliant orange RK, benzidine orange G1 indanthrene brilliant orange GK
.

■Red pigments red pigment Red Garla, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Orange 4R, Pyrazolone Red, Lysole Red, Watching Red Calcium Salt, Lake Red D1, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B1, Acrylic Cow,
Brilliant Carmine B0 ■Purple pigment Manganese purple, First Violet B1 Methyl violet lake.

■Blue pigments navy blue, cobalt blue, American blue lake, Victoria blue lake, phthalocyanine blue, N metal phthalocyanine blue, phthalocyanine blue partially chlorinated product, first sky blue, indanthrenblue-BC.

■Green pigment chrome green, chromium oxide, pigment green B1
Malachite Green Lake, Fanal Yellow Green G.

■White pigment Zinc white, titanium oxide, antimony white 1. Zinc sulfide.

■Extender pigments perlite powder, barium carbonate, clay, silica, white carbon, talc, aluminum white.

[Phase] Oil-based coloring dye ■Inorganic dye These colorants are used in amounts of 1 to 100 parts by weight of the oil-soluble monomer.
It is possible to add 20 parts by weight, particularly preferably 1 part by weight of 5 to 15 parts. Note that among these colorants, oil-based coloring dyes and inorganic dyes are preferred.

(f) Other additives In the production of toner, polymerization accelerators or chain transfer agents may be used if necessary, and these agents may be known per se and may be added as appropriate. Further, in the polymerization step, in order to perform granulation etc. well, surfactants and dispersants which are known per se can be added.

The toner may also contain various compounding agents known per se that are used in this field as shown below.

In order to promote polymerization of oil-soluble monomers and bulk polymers in toner polymerization, a crosslinking agent can be added during suspension polymerization.

Known crosslinking agents are used, such as divinyl compounds such as divinylbenzene, divinyl ether, and divinyl sulfone, diallyl compounds such as allyl phthalate and diallyl carbinol, and diacrylic esters such as diacrylphenol. , ethylene glycol dimethacrylate, trimethylolpropane triacrylate, glycidyl methacrylate, glycidyl acrylate, and the like. Particularly suitable are diacrylic esters.

In order to adjust the chargeability of the toner, charge control agents known per se may be used, such as naphthenic acid, salicylic acid, octylic acid, higher fatty acids, resin acids such as manganese, iron, cobalt, nickel, lead, zinc, cerium, etc. Metal soaps that are metal salts such as carunium; metal-containing azo dyes; pyrimidine compounds; and metal chelates of alkyl salicylic acids are used. These charge control agents are used in an amount of 0.0% per 100 parts by weight of the polymerizable monomer.
Preferably 1 to 10 parts by weight are used, particularly preferably 0.5 to 5 parts by weight.

Furthermore, an anti-offset agent may be added to the toner in order to impart an anti-offset effect to the toner. Examples of the anti-offset agent include various waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and paraffin wax; olefin polymers having 4 or more carbon atoms; fatty acid amides; silicone oil, and the like. These anti-offset agents contain 0 per 100 parts by weight of oil-soluble monomer.
．． The content is preferably 1 to 10 parts by weight, more preferably 1 to 8 parts by weight.

Furthermore, fine powder of a known magnetic material can also be used. For example, triiron tetroxide (Fe30a), iron sesquioxide (γ
-Fe2O3), zinc iron oxide (ZylFe20a), yttrium iron oxide (Y3Fe5O12), cadmium oxide (Cd3F es 012), copper iron oxide (CuFe
20t), iron oxide complex (PbFe 120 +s), iron oxide mangaf (MnFe204), iron neodymium oxide (NdF eo3), iron oxide barium (BaFeu
There are fine powders such as magnesium iron oxide (MgFe20a), lanthanum iron oxide (LaFe○3), iron powder (Fe), cobalt powder (CO), and nickel powder (Ni).

These various ingredients including polymerizable monomers and colorants are thoroughly mixed and dispersed in advance and then subjected to suspension polymerization.

-L second unit [L order The toner of the present invention is produced by suspension polymerization.

Suspension polymerization can be carried out according to a conventional method, in which the polymerizable composition is suspended in an aqueous medium consisting of water and/or an organic solvent miscible with water. The above-mentioned oil-soluble monomer, dispersion stabilizer, polymerization initiator, colorant, and, if necessary, conventionally known additives such as wax and charge control agent are added to the polymerizable composition.

Granulation in an aqueous medium in suspension polymerization can be carried out using a high-speed shearing stirrer such as a homomixer or a homogenizer, and the granulation particle size is generally 3 to 30 μm, particularly 5 to 20 μm.
m is appropriate. The concentration of oil-soluble monomer is generally 1 to 50
% by weight, especially 5-30% by weight is preferred. Examples of the water-miscible organic solvents include lower alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl butyl ketone; ethers such as tetrahydrofuran and dioxane; esters such as ethyl acetate; and dimethyl formamide. Amides such as

The ratio of water and water-miscible organic solvent used varies depending on the aqueous medium and oil-soluble monomer used, but generally water:
The organic solvent may be in any ratio of 100:O to 0:100 (weight ratio), particularly preferably 100:O to 50:50, and it is preferable to select a composition ratio from this range that will result in a homogeneous solution phase. preferable. The amount of the aqueous medium to be used for the oil-soluble monomer is 0.5 to 50 times by weight, especially 5 to 2 times by weight per monomer.
5 times by weight is preferred.

The dispersion stabilizer added to stabilize the suspension state of the oil-soluble monomer is 0.1 to 20% by weight in the suspension system.
Particularly preferred is 0.5 to 10% by weight. pi in aqueous medium (
The dispersion stabilizer is kept in a state in which it does not dissolve, and when a fine powder such as calcium phosphate that is soluble under acidic conditions is used as the dispersion stabilizer, the pH of the aqueous medium is usually 7 to 7. 14, and 6 to 8 when using an amphoteric hydroxide such as aluminum hydroxide.

In this state, the dispersed phase is formed as an oil phase.

In the present invention, a dispersion stabilizer may be added to the aqueous medium in advance prior to adding and mixing the components such as the oil-soluble monomers mentioned above, and the pH value may be adjusted at the same time as suspending particles are prepared. A dispersion stabilizer may be precipitated by adjustment. The amount of dispersion stabilizer used may be small, for example, 100% of the aqueous medium.
It is used within the range of 0.5 part by weight or less, preferably 0.1 part by weight or less.

Next, the suspension is heated to polymerize the oil-soluble monomer in the suspended particles. Polymerization conditions are usually in the temperature range of 30 to 100°C, particularly 40 to 90°C, for 1 to 50 hours.

Through this polymerization, the conversion rate of the oil-soluble monomer in the suspended particles is brought within a predetermined range. The conversion rate can be measured by extracting a portion of the suspended particles present in the reaction system, or by measuring the conditions in which the conversion rate falls within a predetermined range by measuring samples with the same composition and conditions in advance. Good too. The range of conversion rate is as described above, and is usually 80 to 97%,
Particularly preferred is 85 to 95%.

Next, when the conversion rate of the oil-soluble monomer is within a predetermined range, the dispersion stabilizer is dissolved by changing the p)l of the aqueous medium, and the water-soluble monomer present in the aqueous medium is dissolved. The polymer is reacted with the oil-soluble monomer of the suspended particles. At this time,
The pH of the aqueous medium varies depending on the type of dispersion stabilizer used, the type of aqueous medium, the concentration, etc., but is usually 1 to 6. Because the dispersion stabilizer is dissolved and removed by adjusting the pH, the surface of the suspended particles comes into direct contact with the water-soluble monomer, and! ! iI! The oil-soluble monomer present on the surface of the cloudy particles comes to polymerize with the water-soluble monomer.

Here, the water-soluble monomer may be dissolved in advance together with the oil-soluble monomer in an aqueous medium, or may be dissolved in a solution added for pH adjustment. The concentration of the water-soluble monomer in the aqueous medium is generally 0.000
It is preferably 1 to 30% by weight, particularly 001 to 1% by weight. To adjust the pH, for example, the aqueous medium may be made acidic, and the acids used in this case include hydrochloric acid, sulfuric acid,
Examples include mineral acids such as nitric acid, and hydrochloric acid is particularly preferred.

Furthermore, the Mji ratio between the oil-soluble monomer and the water-soluble monomer is 1.
0,000:1 to 100:5 is preferred. According to the present invention, since the oil-soluble monomer and the water-soluble monomer of the suspended particles come into direct contact, the amount of the water-soluble monomer used can be relatively small.

After that, the resin particles generated according to a conventional method are filtered,
After washing and drying, toner particles are obtained.

The particle size of the toner thus obtained is usually 3 to 30
It is μm.

(Example) Hereinafter, the present invention will be specifically explained based on Examples. 5tj 1 part carbon blank, MA-100 (manufactured by Mitsubishi Chemical Corporation, product name)
5 parts by weight Charge control agent, Pontron 5-34 (manufactured by Orinint Chemical, trade name) O, 1M parts Polymerization initiator, 2,2-azobis(2,4-dimethylvaleronitrile) 3 parts by weight Polymerization initiator, Azo 1 part by weight of bisisobutyronitrile [1 part by weight of 6 parts of lucium] and 0.01 part by weight of sodium dodecylbenzenesulfonate were added to 400 parts by weight of water, stirred, and the above mixture was added to this aqueous solution using a taste homomixer. The mixture was granulated, and a polymerization reaction was carried out at 80''C for 8 hours with gentle stirring.The reaction solution was collected at a predetermined time during the polymerization reaction, and its polymerization conversion rate was measured.

As a result, the conversion rate reached 70% 60 minutes after the start of polymerization.
75% after 75 minutes, 80% after 90 minutes, 86% after 120 minutes, 94% after 180 minutes, 9 after 210 minutes.
It had reached 9%.

In Examples 1 to 4 below, the timing of starting acid addition was determined with reference to this relationship between polymerization time and conversion rate.

ffl■ After droplet granulation in Example A, an aqueous solution of 1 part by weight of sodium styrene sulfonate was added to the continuous phase, and 110 minutes after the start of polymerization, 180 parts by weight of 4N hydrochloric acid was added dropwise over 30 minutes. A toner was synthesized in the same manner as in Example A. Toner particles were obtained by treating the obtained polymer with a dilute acid, washing with water, drying, and pulverizing.

When the particle size of the toner was measured using a Coulter counter, the volume-based median diameter D5 [! is 1°, 3μm
This toner was compression-molded into a pellet shape with a compression force of 8.8 kg/am2, and dried for 24 hours in a Tencator containing a force gel desiccant. After that, the contact angle was measured by an improved hot method and was found to be 72°.

Additionally, 0.1 parts by weight of hydrophobic fine powder was mixed with 100 parts by weight of the obtained toner, and the mixture was mixed with a ferrite carrier coated with Nricorn resin to give a toner concentration of 3.
% developer was prepared. The amount of charge of this developer was measured using the convex-off method and was found to be -37 μC/g. In addition, in order to measure the distribution of charge polarity of the toner, a width of 70tnrrr, a gap width of 5mm, and an applied voltage of 1mm were used.
950mm/s between vertically arranged parallel electrodes of 500V
When I introduced airflow with ee and let the developer fall, +
Toner adhered only to the side electrode, and no door adhered to the - side electrode. This shows that almost no positively charged toner exists.

Furthermore, using an electrophotographic copying machine, DC-2585 (manufactured by Mitsubishi Kasei Corporation, trade name), we investigated toner scattering and background cover images under conditions of room temperature and normal humidity, high temperature and high humidity, and low temperature and low humidity. Image characteristics such as density and resolution were evaluated. No toner scattering into the copying machine was observed, and good images were obtained.

Example 1 was repeated in Example 1 except that 1 part of 4N hydrochloric acid was added dropwise 165 minutes after the start of polymerization.
A toner was synthesized and evaluated in the same manner as described above.

The resulting toner had a median diameter Dsa of 9.5 μm and a soarp particle size distribution, and the contact angle of a pellet formed with this toner was 74°.

In addition, the amount of charge of the developer using this toner is -39 μC.
/g, and the developer contained almost no positively charged toner. Further, no toner scattering into the copying machine was observed, and good images were obtained.

A toner was synthesized and evaluated in the same manner as in Example 1, except that 2.5 parts by weight of phenylvinylphosphonic acid was used instead of 1 part by weight of sodium styrene sulfonate.

The obtained toner had a median diameter I)se of 10.8 μm and a glossy particle size distribution, and the contact angle of a pellet formed with this toner was 65°.

In addition, the amount of charge of the developer using this toner is -34 μC.
/g, and the developer contained almost no positively charged toner. Further, no toner scattering into the copying machine was observed, and good images were obtained.

K Arashi 5± In Example 1, sodium styrene sulfanate 1
A toner was synthesized in the same manner as in Example 1, except that 25 parts by weight of phenylvinylphosphonic acid was used instead of f'Jli, and 181 parts by weight of 4N hydrochloric acid was added dropwise 165 minutes after the start of polymerization. and evaluated.

The resulting toner had a median diameter D6i1 of 11.0 μm and a soaring particle size distribution, and the contact angle of the pellet formed with this toner was 68°.

Also, the amount of charge of the developer using this toner is -30 μC.
/g, and the developer contained almost no positively charged toner. Further, no toner scattering into the copying machine was observed, and good images were obtained.

Styrene 82 parts by weight 2-ethyl hexyl methacrylate tg Lffls 2-ethylene glycol dimethacrylate 1.5 parts by weight Divinylbenzene (1,5 parts by weight
i Carbon black, MA-100 (manufactured by Mitsubishi Kasei Co., Ltd., trade name) 5 parts by weight Charge control agent, Bontron 5-40 (manufactured by Orient Chemical Co., Ltd., trade name) 05 parts by weight Polymerization initiator, 2.2-Azobis(2, 4-dimethylvaleronitrile) 3 parts by weight of a polymerization initiator, 1 part by weight of dimethyl azobisisobutyrate, 7 parts by weight of aluminum carbonate, and 1 part by weight of sodium dodesolbenzenesulfonate were added to 400 parts by weight of water and stirred to form an aqueous solution. The above-mentioned mixture was added to the solution, granulated using a homomixer, and a polymerization reaction was carried out at 80° C. for 8 hours with gentle stirring. The reaction solution was collected at a predetermined time during the polymerization reaction, and the polymerization conversion rate was measured.

As a result, the conversion rate reached 70% 45 minutes after the start of polymerization.
77% after 60 minutes, 83% after 75 minutes, 85% after 90 minutes, 92% after 120 minutes, 99 after 180 minutes.
% had been reached.

An aqueous solution of 2 parts by weight of phenylvinylphosphonic acid was added to the continuous phase after droplet granulation in Example B, and 4 parts by weight of phenylvinylphosphonic acid was added 75 minutes after the start of polymerization.
A toner was synthesized in the same manner as in Example B, except that 180 parts by weight of the specified hydrochloric acid was added dropwise over 30 minutes, and evaluated in the same manner as in Example 1.

The median diameter I)ss of the obtained toner is 9.7 μm/
The toner had a narrow particle size distribution, and the contact angle of the bezel () formed with this toner was 63°.

In addition, the amount of charge of the developer using this toner is -41 μC.
/g, and the developer contained almost no positively charged toner. Furthermore, no scattering of the door into the copying machine was observed, and good images were obtained.

In Example 5, a toner was synthesized and evaluated in the same manner as in Example 5, except that 180 parts by weight of 4N hydrochloric acid was added dropwise 140 minutes after the start of polymerization.

The median diameter I)sii of the obtained toner is 89 μm and 7
The toner had a uniform particle size distribution, and the contact angle of the pellets formed with this toner was 64°.

In addition, the amount of charge of the developer using this toner is -39 μC.
/g, and the developer contained almost no positively charged toner. Further, no toner scattering into the copying machine was observed, and good images were obtained.

Yo! Door (no water-soluble monomer added) was synthesized according to the method of Example A, and evaluated by the same method as Example 1.

The metian diameter I)sii of the obtained door was 10.5 μm
The toner had a particle size distribution of 7 yarns, and the contact angle of the pellets formed with this toner was 75°.

Also, the amount of charge of the developer using this toner is -24 μC.
The presence of positively charged toner was confirmed. Furthermore, a small amount of toner was observed to be scattered inside the copying machine, and background fog was observed in the image, resulting in only a low-resolution image.

Comparative Example 2 A toner (to which no water-soluble monomer was added) was synthesized according to the method of Example B, and evaluated in the same manner as in Example 1.

The resulting toner had a median diameter D51I of 9.8 μm and a sharp particle size distribution, and the contact angle of the pellet formed with this toner was 73°.

In addition, the amount of charge of the developer using this toner is -27 μC.
The presence of positively charged toner was confirmed. Furthermore, a small amount of toner was observed to be scattered inside the copying machine, and background fog was observed in the image, resulting in only a low-resolution image.

In Example 1, a toner was synthesized in the same manner as in Example 1, except that 180 parts by weight of 4N hydrochloric acid was added dropwise 75 minutes after the start of polymerization. After a few minutes, the toner particles become a clump that is fused together.
No fine particle toner was obtained.

Comparative Example 4 A toner was synthesized and evaluated in the same manner as in Example 1, except that 180 parts by weight of 4N hydrochloric acid was added dropwise 210 minutes after the start of polymerization.

The resulting toner had a median diameter D511 of 9.9 μm and a glossy particle size distribution, and the contact angle of the pellet formed with this toner was 74°.

In addition, the amount of charge of the developer using this toner is -27 μC.
The presence of a small amount of positively charged toner was confirmed. Furthermore, there was a slight scattering of toner inside the copying machine, and there was some background fogging on the image.
Only low-resolution images were obtained.

In Example 1, 25 parts by weight of phenylvinylphosphonic acid was used instead of 1 part by weight of sodium styrene sulfonate, and 180 parts by weight of 4N hydrochloric acid was dropped 75 minutes after the start of polymerization. synthesized a toner in the same manner as in Example 1, but about 10 minutes after the start of addition of hydrochloric acid, the toner particles became a lump that was fused to each other, and a fine particle toner could not be obtained.

In Example 1, 25 parts by weight of phenylvinylphosphonic acid was used instead of 1 g by weight of sodium styrene sulfonate, and 180 parts by weight of 4N hydrochloric acid was dropped 210 minutes after the start of polymerization. A toner was synthesized and evaluated in the same manner as in Example 1.

The resulting toner had a median diameter D511 of 112 μm and a soaring particle size distribution, and the contact angle of the pellet formed with this toner was 73°.

In addition, the amount of charge of the developer using this toner is -23 μC.
The presence of a small amount of positively charged toner was confirmed. Furthermore, there was a slight scattering of toner inside the copying machine, and there was some background fogging on the image.
Only low-resolution images were obtained.

A toner was synthesized in the same manner as in Example 5, except that 180 parts by weight of 4N hydrochloric acid was added dropwise 60 minutes after the start of polymerization. After a few minutes, the toner particles became a clump that was fused to each other, and no fine particle toner was obtained71).

In Example 5, a toner was synthesized and evaluated in the same manner as in Example 5, except that 180 parts by weight of 4N hydrochloric acid was added dropwise 180 minutes after the start of polymerization.

The resulting toner had a median diameter DSe of 9.7 μm and a 7-yave particle size distribution, and the contact angle of the pellet formed with this toner was 72°.

In addition, the amount of charge of the developer using this toner is -28 μC.
The presence of a small amount of positively charged toner was confirmed. Furthermore, there was a slight scattering of toner inside the copying machine, and there was some background fogging on the image.
Only low-resolution images were obtained.

Mustache distyrene 70 parts by weight n-butyl methacrylate 30 parts 2-ethyleneglyfur dimethacrylate 15 parts by weight Carbon black, MA-100 (manufactured by Mitsubishi Kasei Corporation, trade name) 5 parts by weight Charge control agent, Hontron 5- 36 (manufactured by Orient Chemical, trade name) 1 part by weight low molecular weight polypropylene, 1.5 parts by weight of Bisfur 550P (manufactured by Sanyo Kasei, trade name) Polymerization initiator, 4 parts by weight of azobisisobutyronitrile A mixture of these was mixed with water. After adding 400 parts by weight and 10 parts by weight of polyvinyl alcohol into a continuous phase and granulating it using a homo mixer, 0 parts of sodium styrene sulfonate was added.
．． 25 parts by weight were dissolved in a suspension and a polymerization reaction was carried out at 80'C for 5 hours with gentle stirring. Toner particles were obtained by washing the obtained polymer with hot water, filtering, drying, and pulverizing.

When the particle size distribution of the toner was measured using a Coulter counter, the volume-based median diameter D6i1 was 103μ.
The toner had a sharp particle size distribution, and the contact angle of the pellet formed with this toner was 52.

01 parts by weight of hydrophobic silica fine powder was mixed with 100 parts by weight of the obtained toner, and the mixture was mixed with a ferrite carrier coated with phosphoricone resin to prepare a developer having a toner concentration of 3% by weight. Electrophotocopy machine, DC-1001 (
Image characteristics were evaluated under each environmental condition of room temperature/room temperature, high temperature/high humidity, and low temperature/low humidity using a product manufactured by Sanda Kogyo ■ (trade name). The developer band it using this toner is 117
Although the developer was 9 μC/g and contained almost no positively charged toner, background fog and toner scattering occurred due to a decrease in the amount of charge in a high temperature and high humidity environment.

A toner was synthesized and evaluated in the same manner as in Comparative Example 9, except that 0.6 parts by weight of phenylvinylphosphonic acid was used instead of 0.25 parts by weight of sodium styrene sulfonate in Comparative Example 9.

The median diameter I)si+ of the obtained toner is 11.0μ+
It had a tenosave particle size distribution and a contact angle of 49°.

The amount of charge of the developer using this toner is -15.4μC/
Although the developer had almost no positively charged toner, it caused background fog and toner scattering due to a decrease in the amount of charge in a high-temperature, high-humidity environment.

(Effects of the Invention) According to the present invention, it is possible to provide a toner for developing an electrostatic image that has superior moisture resistance and excellent triboelectric charging properties and charge control properties as compared to conventional ones, and a method for producing the toner. Images can be formed without causing scattering or background fog, and furthermore, there is no reduction in image density or resolution.

Furthermore, since a copolymer of a water-soluble monomer and an oil-soluble monomer is present on the surface of the toner, it is also possible to reduce the cost by reducing the amount of charge control agent added.

that's all

Claims (1)

[Scope of Claims] 1. A water-soluble polymer obtained by a suspension polymerization method using a dispersion stabilizer consisting of a poorly water-soluble inorganic fine powder, containing a water-soluble monomer and an oil-soluble monomer as constituent components, and A toner for developing an electrostatic image containing fine resin particles on the surface of which a copolymer of a monomer and an oil-soluble monomer is present, the surface of a molded article obtained by compression molding the toner. A toner for developing electrostatic images having a contact angle with water of 60° or more. 2. A step of producing suspended particles by suspending an oil-soluble monomer in an aqueous medium using a dispersion stabilizer consisting of a poorly water-soluble inorganic fine powder; a step of polymerizing the monomer until the conversion rate of the oil-soluble monomer reaches a predetermined range; when the conversion rate of the oil-soluble monomer falls within a predetermined range, the dispersion stabilizer is dissolved by changing the pH of the aqueous medium; A method for producing a toner for developing an electrostatic image, comprising the step of producing fine resin particles by reacting a water-soluble monomer present in an aqueous medium with an oil-soluble monomer in suspended particles.