JPS60225170A - Production of toner for electrophotography - Google Patents

Abstract

PURPOSE:To provide excellent image density, resolution and gradation characteristic and excellent durability and moisture resistance in particular and to improve cleanability, electrification stability and blocking property by subjecting an emulsion polmyer liquid to salting out at a specific temp. or heating the particles obtd. after the salting-out to a specific temp. CONSTITUTION:A main resin component is produced by emulsion polymn. and thereafter a salting-out agent is added to the resulted emulsion polymer liquid and the liquid is subjected to salting out. The salting out is required to be executed at the temp. below the glass transition point of the main resin component or the particles after the salting-out are required to be heated to the temp. above the glass transition point of the main resin component (to be subjected to heat treatment). The bulk density of the particles is increased, the moisture resistance and durability are improved and particularly the durability is best improved by the heat treatment. The heat treatment temp. is preferably 150 deg.C at the upper limit. Not only the main resin component becomes susceptible to deterioration but also the heating installation becomes intricate if the temp. is too high. The most preferable heat treatment temp. is the temp. higher by 25-60 deg.C that the glass transition point of the main resin component.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing an electrophotographic toner using an emulsion polymerization method.

(Prior art) In electrophotography, after uniformly charging a photoreceptor,
The photoreceptor is exposed to a light image based on the original image, and the charge on the light-irradiated area is eliminated or reduced.

Forms an electrostatic latent image on the photoreceptor based on the original image.

Thereafter, it is visualized using a developer containing toner. This visualized toner image is generally transferred to a suitable transfer member and fixed thereon to form a so-called copy.

The developer used in the above process basically consists of a coloring agent to visualize the electrostatic latent image and a binder to fix the developed image to the transfer body. are broadly classified into so-called wet (liquid) developers and dry developers.

Dry developers can be further divided into two-component developers and one-component developers, with the former consisting of a carrier and toner, and the latter consisting only of toner. In other words, a two-component developer is one that obtains toner of opposite polarity to the electrostatic charge image required to develop the electrostatic charge image on the photoconductor by frictional charging between the carrier and the toner. A one-component developer is one that is charged by friction between the two or other members in the developing device.

Conventionally, toner for such a dry developer is generally prepared by melting and kneading a coloring material such as carbon black and/or a magnetic powder such as magnetite in a thermoplastic resin to form a dispersion, and then appropriately pulverizing the dispersion. The toner has been manufactured by applying mechanical impact force using a device to crush the dispersion to a desired particle size, and if necessary, further classifying it to form a toner (described below).

This method is called the crushing method).

Such methods not only require a large amount of energy for melt mixing and crushing.

The produced toner necessarily has a number of drawbacks.

Regarding the use of desirable resins in the melt-mixing process and the crushing process, for example, if a resin that is easily melted is used, it may cause aggregation (caking) during toner storage or toner filming on the photoreceptor. Furthermore, if a resin that is pulverizable is used, it will be pulverized into fine toner particles in the developing machine, resulting in two-image fog and dirt inside the machine.

In addition, the colorant dispersed in the resin appears on the surface of the crushed toner, resulting in a decrease in the amount of triboelectric charge in high humidity conditions, and the colorant falling off in the developing machine. This causes undesirable phenomena such as contamination of the carrier surface and contamination of the photoreceptor surface.

In order to solve these drawbacks of the pulverization method, the Special Publication No. 43-1
Japanese Patent No. 0799 proposes a method for producing completely spherical toner particles by spray drying an emulsion obtained by emulsion polymerization.

In addition, as a toner production method using a polymerization method in order to solve the drawbacks of the pulverization method, a toner production method using a suspension polymerization method is described in Japanese Patent Publication No. 14895/1989, Japanese Patent Application Laid-open No. 53756/1983, etc. Proposed. When using the suspension polymerization method, a perfectly spherical toner can be obtained.

Conventionally, toners obtained using such polymerization methods are
Although some of the drawbacks of toners obtained by the grinding method have been overcome, it has been found that new drawbacks are introduced. That is, since the emulsifier or suspending agent remains in the toner particles, charging stability and blocking properties are reduced, and the resulting toner particles are spherical, resulting in poor cleaning properties.

On the other hand, when toner is manufactured by emulsion polymerization.

Although it is possible to recover particles by salting out the emulsion polymerization liquid and pulverize them to an appropriate particle size, this method has the disadvantage that the durability and moisture resistance of the resulting toner are significantly reduced.

As described above, in the past, it has not been possible to obtain a fully satisfactory toner using the four methods.

(Object of the Invention) The present invention solves the problems in the conventional toner manufacturing method, and involves two-image production.

The emulsion polymerization method is used to develop electrophotographic toners that are suitable for dry development and that can improve cleaning performance, charging stability, and blocking properties, as well as poor resolution and gradation. The present invention provides a manufacturing method using

(Structure of the Invention) The present invention involves producing a main resin component by emulsion polymerizing an associable monomer in the presence of a coloring agent and/or magnetic powder, and using the obtained emulsion polymerization liquid as a main resin component. The present invention relates to a method for producing an electrophotographic toner, which comprises salting out at a temperature higher than the glass transition point or heating particles obtained after salting out to a temperature higher than the glass transition point of the main resin component.

The emulsion polymerization of the polymerizable monomer in the present invention is carried out by emulsifying and dispersing the monopolymerizable monomer in an aqueous medium containing an emulsifier and polymerizing the monomerizable monomer.

During this emulsion polymerization, an N colorant and/or magnetic powder and a polymerization initiator are allowed to exist. others.

Off-cent prevention agent, charge control agent, fluidity improver.

A toner property improving agent such as a cleaning performance improving agent, a stabilizer for assisting emulsification and dispersion, and a chain transfer agent may be appropriately present.

As a method for emulsifying and dispersing a polymerizable monomer in an aqueous medium, one polymerizable monomer, an emulsifier, and an aqueous medium may be stirred and mixed at the same time.
The λ form may be added and mixed by stirring.

The polymerization initiator may be added after this emulsification and dispersion, but
It is preferable to dissolve the water-soluble polymerization initiator in advance in an aqueous medium during emulsification and dispersion. As the single-polymerization initiator, a di-soluble polymerization initiator can be used in combination, and it is preferable to dissolve this in advance in the monopolymerizable monomer.

In order to improve dispersion in the resin, the colorant and/or magnetic powder is preferably used after being dissolved or dispersed in the polymerizable monomer in advance, rather than being added after the emulsification and dispersion. The same applies to toner property improvers that are used as needed. Furthermore, stabilizers may be used as needed;

It may be added after the emulsification and dispersion, or it may be used after being dissolved in an aqueous medium in advance.

Stirring and mixing in the emulsification and dispersion may be carried out at relatively high speed using an ordinary stirrer, but it is preferable to use a homomixer or the like to perform stirring using high-speed shearing.

This also applies to the case where a colorant and/or magnetic powder and an optional toner property improver are dispersed in the dipolymerizable monomer.

Emulsion polymerization is carried out after or during emulsion dispersion,
It is preferable to carry out the process at a temperature of 20 to 120°C, especially at a temperature of 5.
Preferably, it is carried out at a temperature of 0 to 80°C.

This emulsion polymerization is preferably carried out until the polymerization rate reaches 99% by weight, particularly preferably 99.9% by weight or more. If the polymerization rate is low and there is a large amount of residual toner, the toner properties, especially the storage stability, tend to be poor.

Further, the polymer obtained by emulsion polymerization preferably has a weight average molecular weight of 50,000 or more. If the molecular weight becomes too small, cleaning/greasing properties and blocking resistance tend to deteriorate.

Moreover, the obtained polymer has a glass transition point of 30 to 90°.
It is preferably C, particularly preferably 50 to 80°C. If the glass transition point is too low, the blocking resistance will decrease, and if it is too high, the fixing ability will decrease. The glass transition point can be adjusted mainly by selecting the polymerizable monomer to be used.

Such emulsion polymerization yields particles of about 3 μm or less.

Next, materials used for emulsion polymerization will be explained.

Examples of the polymerizable monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, p-
Ethylstyrene, 2,4-dimethylstyrene, p-n-
Butylstyrene p-1 crt-butylstyrene, p
-n-hexylstyrene, p-n octylstyrene, p
-n-nonylstyreno.

p-n-tethylstyrene, p-n-dodenorstyrene, n-meth)oxystyrene, p-phenylsf-rene, p
Styrene and its derivatives such as chlorostyrene and 3,4-dichlorostyrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; Vinyl rogens, vinyl acetate, vinyl propionate.

Vinyl esters such as vinyl penzoate and vinyl butyrate, methyl acrylate, and 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 a-chloroacrylate, methyl methacrylate, edyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, methacrylate stearyl acid, phenyl methacrylate, dimethylamine ethyl acrylate, dimethylaminoethyl methacrylate,
α-notylene aliphatic monocarboxylic acid esters such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, acrylic acid 2
Hydroxyethyl, 2-hydroxypropyl acrylate,
Acrylic acid or methacrylic acid derivatives such as 2-hydroxyethyl methacrylate and 2-hydroxyprobyl methacrylate, and in some cases, acrylic acid, methacrylic acid, maleic acid, fumaric acid, etc. can also be used. Also, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl methyl ketone,
Take 1 weigh of vinyl ketone M such as vinylhexyl ketone and methyl isopropenyl ketone, N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbasol, N-vinylindole, and N-vinylpyrrolidone, vinylnaphthalene salt, etc. Can be used in combination with more than one species. Among these polymerizable monomers, styrene or styrene derivatives are
Using a toner in the range of 0 to 100 weight provides excellent fixing properties when the toner is copied onto paper using an electrophotographic copying device.

Further, as the polymerizable monomer of the present invention, a compound capable of curing two or more polymerizable double bonds, which serves as a crosslinking agent, can also be used in part. An example is divinylbenzene.

Aromatic divinyl compounds such as divinylnaphthalene and derivatives thereof, diethylene carboxylic acid esters such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol triacrylate, trimethylolproban triacrylate, N,N divinylaniline, divinyl ether , divinyl sulfite, and compounds having three or more vinyl groups can be used alone or as a mixture. The amount of crosslinking agent used is preferably 0 to 20% by weight based on the total amount of polymerizable monomers.

Particularly preferred is KO to 5% by weight.

The aqueous medium used in emulsion polymerization is mainly water. What is the ratio of the above polymerizable monomer to the aqueous medium?

The weight ratio of the former/latter is preferably 40/60 to 90/10. If this ratio is too small, emulsion polymerization becomes difficult,
If it is too large, the yield will decrease.

As the emulsifier, anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants can be used. Of these, corner belt 1E
It is preferable to use an anionic surfactant when producing a positive chargeable toner, and use a cationic surfactant when producing a positively chargeable toner. In these cases, in order to improve the dispersion stability, it is preferable to use a nonionic surfactant in combination.

As anionic surfactants, fatty acid salts such as sodium oleate and potash human oil, alkyl sulfate esters such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzenesulfonates such as sodium dodebulbenzenesulfonate, alkylnaphthalene sulfones, etc. Examples include acid salts, dialkyl sulfosuccinates, alkyl phosphate Nisder salts, naphthalene sulfonic acid formalin condensates, and polyoxyethylene alkyl sulfate ester salts.

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxynorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin, fatty acid ester, and Examples include ethylene-oxypropylene block polymers.

Examples of cationic surfactants include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride and stearyltrimethylammonium chloride.

Examples of the zwitterionic surfactant include lauryltrimethylammonium chloride.

The amount of emulsifier used is 0.01 to 1 per 9 polymerizable monomers.
It is preferably 0% by weight, particularly preferably 0.5 to 5% by weight. If the amount of emulsifier used is too small, stable emulsion polymerization will be difficult, and if it is too large, the resulting toner will have poor moisture resistance.

Stabilizers include polyvinyl alcohol, starch,
Water-soluble disease molecules such as methylcellulose, methyl cellulose and hydroxyethylcellulose are used, and it is preferable to use them in an amount of 0 to 1% by weight based on the monopolymerizable monomer.

Examples of water-soluble polymerization initiators that can be used in the present invention include:

For example, sulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, 4,4'-azobiscyanovalericand, 2,2'-azobis(2-amidinopropane) dihydrochloride, t-butylhydrochloride, Peroxide, cumene hydroperoxide, etc. can be used. Especially when using persulfates.

The sulfate anion radical (S
O4-) exists on the surface of the monomer, and the particles are stabilized by the hydrophilicity and electrification of the SOa group, making it easy to obtain an emulsion having a relatively uniform particle size.

The amount used is o, oi ~ 10% by weight based on the polymerizable monomer.
is preferable, and particularly preferably 0.1 to 5% by weight.

If the amount of polymerization initiator is too small, the polymerizable monomer will not be completely polymerized and will remain in the toner, impairing the properties of the toner.

As a polymerization initiator, benzoyl peroxide, t-
Peroxides such as butyl perbenzoate.

Oil-soluble polymerization initiators such as azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile can be used in combination. The oil-soluble polymerization initiator is preferably used in an amount of 100% by weight or less based on the water-soluble polymerization initiator.

The above water-soluble polymerization initiator may be used in combination with a reducing agent. As the reducing agent, there are commonly known ones such as sodium metabisulfite and JI iron chloride. The reducing agent does not necessarily need to be used, but when used, it is preferably used in an amount equal to or less than the amount of the water-soluble polymerization initiator.

Examples of chain transfer agents include alkyl mercaptans such as t-dodecyl mercaptan, lower alkyl xantogens such as diisopropyl xanthocene, carbon tetrachloride, carbon tetrabromide, etc. Preferably, % by weight is used.

Colorants preferably used in the present invention include:

Mention may be made of pigments or dyes9 such as various carbon blanks, nigrosine dyes (C,1,Nα 150
415), Aniline Blue (C,1,Nα50405
).

Calco oil blue (C, 1, Ha azoec Bl
ue 3) + chrome 1 yellow < C, r, Nα1-
1090), Ultramarine Blue (C,1,Nc
i77103), DuPont Oil Lend (C, 1, and 2
6105), Melient Oil Reddna 330 (C,
1, Na30505), quinoline yellow (C, 1, N
ci47005), methylene blue chloride (C-I
-Nα52015), phthalocyanine blue (C,1,
stone 74160), malachite green oxalate (C
,1,Nα42000), lamp blank (C,1,N
α77266), Rose Bengal (C, 1, round 4543
5) Oil black, aluminum oil blank, etc. can be used alone or in combination. These colorants can be used in various colors, but for economical reasons and to obtain a high density, the colorants should be added to the toner by about 1 to 30 watts, and each colorant should be about 5 to 15 watts by weight. % is used.

Pigments or dyes which have been subjected to various treatments for the purpose of increasing their dispersibility in the polymerization reaction system or in the toner of the present invention may be used.

The above-mentioned treatments include 2, for example, Nidalon dyeing M (C, I).

Nci50415) can be treated with organic acids such as stearic acid and maleic acid.

Among these colorants, one particularly preferred in the toner of the present invention is various carbon blacks, such as furnace blank, channel black, thermal blank, acetylene blank, lamp blank, and the like. Furthermore, the carbon black may be surface-treated. As for surface treatment.

Examples include oxidation treatment using various oxidizing agents such as oxygen, ozone, and nitric acid, and surface adsorption treatment with organic acid Nisdel such as dibutyl phthalate and dioctyl phthalate.

When using carbon black as a colorant, it is preferable to use a grafted carbon blank. What is a grafted carbon blank?

It is obtained by polymerizing the above-mentioned polymerizable monomers by a method such as bulk polymerization or solution polymerization in the presence of a carbon blank. The polymer component of grafted carbon black is
It is preferably 50% by weight or less, particularly 30% by weight or less, 9% by weight or less relative to the grafted carbon black. Grafted carbon blanks are clever because they have excellent dispersion stability when combined with emulsion 1, but if the monopolymer acid content is too large, the viscosity tends to be too high when dispersed in a polymerizable monomer. 1. Workability is likely to decrease. The usability of the grafted carbon blank is preferably determined by the amount of carbon blank components.

Magnetic powder is used when manufacturing magnetic toner.

This can double as a coloring agent. Preferred magnetic powders include, for example, oxides or compounds of iron such as magnetite or ferrite, or ferromagnetic elements such as nickel and cobalt. These magnetic powders have a particle size of 0.01 to 3 μm and are light and heavy, and the surface of the magnetic powder is resin.

Titanium coupling agent, silane coupling agent.

It may be treated with commercial grade fatty acid gold nine salts or the like.

These magnetic substances can be contained in an amount of 20 to 800 to 80% by weight or 35 to 70% by weight with respect to the toner. Less than this amount may be used as one coloring agent.

An offset inhibitor is used as necessary. The anti-offset agent is present in the system in various forms during polymerization and can be incorporated into the toner product. Alternatively, the anti-offset agent can be added later to the toner of the present invention in which no anti-offset agent is present.

The offset inhibitor 2 and 1 various natural waxes,
For example, carnauba wax, hydrogenated castor oil.

Although low molecular weight olefin polymers and the like can be used in the present invention, low molecular weight olefin polymerizable materials are preferably used.

As this low molecular value 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.
Acrylic acid ester is a monomer other than olefin.

Examples include methacrylic acid esters. Examples of this low molecular weight olefin polymer include 2, for example, JP-A-55-15394
Polyalkylene described in Publication No. 4, JP-A-50-9
The low molecular weight olefin copolymer described in Japanese Patent No. 3647 can be used.

The molecular weight of the low molecular weight olefin polymer of the present invention may be any one that conforms to the concept of low molecular weight of ordinary polymer compounds, but generally Vi weight average molecular weight %i (M w )
1,000~45,000. Good 1 trip 2,000~
6. OOOO Monoderoru.

The low molecular weight polyolefin polymer of the present invention has a softening point of 10
Those having a CI of 0 to 180°C, particularly 130 to 160°C are preferred.

The amount of the low molecular weight olefin a combination that can be used in the present invention is not particularly limited, but is preferably in the range of 0 to 30% by weight based on the weight of the toner.

More preferably, it is used in an amount of 1 to 30 tons. Low minute J'
If the amount of +A oleoy/polymer is too small, the off-cent effect due to its addition will not occur, and if it exceeds 30 bts, gelation may occur during the polymerization reaction.

Furthermore, a fluidity improver, a cleanliness improver, etc. can be used as necessary. These can be present in the polymerization reaction system and then present in the product toner, but preferably they are externally added to the product toner afterwards. The content of these compounds is preferably 0% to 3% fI-% relative to the toner of the present invention. Fluidity improvers include Nran and titanium.

There are oxides of aluminum, calcium, magnesium, and magnesium, or those obtained by hydrophobicizing the above oxides with a titanium coupling agent or a run coupling agent. Cleanability improvers include zinc stearate, lithium stearate, and These include metal salts of primary fatty acids such as magnesium laurate, or aromatic acids such as pentaerythritol benzoate.

In the present invention, by selecting monopolymerizable monomers and colorants, it is possible to freely adjust the so-called band '1ttf and charge polarity of the product toner, but in order to adjust the charge amount and charge polarity to more desired values. A so-called charge control agent can also be used in the toner of the present invention in combination with the colorant.

As a charge control agent preferably used in the present invention, Vil such as Spironoblank TRH, Spironoblank TPH
Azo dyes such as (Hodogaya Chemical) 9 e.g. p-fluorobenzoic acid, p-nitrobenzoic acid.

2. Aromatic acid derivatives such as 4-di-t-butylsalicylic acid 1 Examples include tin compounds such as dibutyl-tin oxide and dioctyl tin oxide.

These are light and heavy when used in an amount of 0 to 5% by weight based on the dipolymerizable monomer.

In the present invention, after producing the main resin component by emulsion polymerization, the obtained emulsion iT1 compound QK! Add irr agent and salt. Book '76'! jl! '(Oitej7.7 r-r: H+, J.

It is carried out at a temperature above the glass transition point of the main resin component, or after heating the particles to a temperature above the glass transition point of the main resin component (hereinafter referred to as "heat treatment") is necessary.

This heat treatment increases the bulk of each particle and improves moisture resistance and durability. In particular, durability is best improved.

The upper limit of the heat treatment temperature for yf-4 is 150°C.

If this temperature is too high, not only will the main resin components be susceptible to deterioration, but the heating equipment will also become complicated.

The heat treatment temperature is 25° below the glass transition point of the main resin component.
Temperatures ~60°C higher are most preferred.

The above-mentioned salting-out can be carried out by mixing the emulsion polymerization liquid and the salting-out agent aqueous solution at a fixed ratio, by dropping the emulsion polymerization liquid little by little into the salting-out agent aqueous solution while stirring, and by heat treatment during salting-out. This can be carried out by heating the mixture produced in the above operation.

When heat treatment is performed after salting out, the temperature during salting out is not particularly limited. This heat treatment may be carried out by continuously heating the salting-out solution after salting out, or by once separating one particle, inserting a washing step or a pulverizing step depending on the case, dispersing it in an aqueous medium, and heating it. Good too. I cut it. In some cases, heat treatment during salting out and heat treatment after salting out may be used together.

In the above salting out, the particle size component of the obtained particles is 1 to 10
It is preferable to adjust it to 0 μm, especially 3 to 7
0μmVC? It is preferable to set it to A.

It is most preferable to adjust the particle size so that the main component is particles of 5 to 25 μm. The average particle size is 9 to 15 μmK.
, d1 are preferably arranged. For this reason, it is recommended that K be used in an amount of 01 to 5 times the weight of the emulsifier in the emulsion polymerization solution, and particularly 0.3 to 3 times the weight of the emulsifier in the emulsion polymerization solution. This is one IC.

Since the obtained particles can be made into a toner by simply dividing the particles as they are or by dividing them into two, a pulverization step is not necessary, and therefore, the drawbacks of toners produced by the pulverization method can be solved. Moreover, since incompletely spherical toner particles are obtained by salting out, the toner particles have excellent cleaning/gluing properties.

In the above-mentioned salting out, large particles of 100 μm or more may be produced, and in this case, a pulverization step is necessary to obtain a particle size suitable for the toner particles.

In this case, since heat treatment is performed in the present invention, the bulk density of the particles increases, and therefore, moisture resistance and durability can be improved. In addition, the N colorant and/or magnetic powder and the toner property improver used as necessary are:
It is possible to solve the disadvantages of the pulverization method toner, such as good dispersion in the resin and the fact that only a slight amount of pulverization is required.

Examples of salting-out agents include inorganic acids such as hydrochloric acid and sulfuric acid, salting acids such as hydrochloric acid and oxalic acid, and these acids and alkaline earth gold + 4i.
A water-soluble 1'l consisting of , 'f Lumie Uno, L: Kingara salt, etc. These salting-out agents can be used alone or in combination, but the ideal salting-out agents are magnesium sulfate, sulfuric acid, etc. Aluminum, barium chloride, magnesium chloride, calcium chloride, sodium chloride and/or a combination thereof with an inorganic acid. These salt preparations are 0.
It is preferably used as a 1 to 10% aqueous solution, especially a 01 to 5% aqueous solution.

The liquid obtained through the salting out step (and heat treatment step) is in the form of a slurry, which can be centrifugally dehydrated to isolate particles, which are further washed and dried, and optionally further Classify.

It is considered to be a toner for electrophotography.

Here, in particular, washing further removes the emulsifier attached to the toner, which contributes to improving the band stability and blockiness of the toner obtained in the above-mentioned salting out process. The monkey is the one who does it.

(A, rf is recommended to be carried out using hot water of 40 to 70°C, but it may be less than 40°C.

The toners obtained according to the present invention can be subjected to various development processes, such as the cascade development method described in U.S. Pat. No. 2,618,552, the magnetic plan method described in U.S. Pat. No. 4,874,065.

The powder-coupling method described in U.S. Patent No. 2,221,776, the touchdown development method described in U.S. Pat. Microtoning method 9 A submicrotoning method using a magnetic toner produced by a pulverization method as a carrier.

It can be used in the newly developed bipolar machining toner method, which obtains the necessary toner charge by frictional charging between magnetic toners.

Furthermore, the toner obtained according to the present invention can be used in various fixing methods.
For example, it can be used in the Shinkai oil-less method, the oil-coated heat roll method, the flagille method, the oven method, the pressure fixing method, and the like.

Furthermore, the toner of the present invention can be cleaned using a moderate cleaning method 1.
For example, it can be used in the so-called fur brush method, play 1' method, and the like.

(Example) Next, three examples of the present invention will be described. Hereinafter, ``chi'' means weight person.

Example 1 (1) Production of emulsion polymerization solution 31! Craft carbon (craft carbon () P-E ~ 2 made by Enyu Kogyo ■) 1009 in a stainless steel beaker
Stire/4oog as a polymerizable single spear body.

120 g of butyl acrylate and 0.69 kura of 1-dotene lumel butane as a continuous transfer agent, 3 o in a homomixer
Mixing and dispersion was performed for 30 minutes using o o r, p, and m.

Next, ion exchange water 13009 was added to this carbon dispersion.
Sodium totinolbenzenesulfonate 129 mixed with an anionic surfactant as an emulsifier, Nonipol PE-68 mixed with a nonionic surfactant (Sanyo Chemical Industries ■Oxypropylene-oxy/ethyleneprone polymer) 39. Neugen EA170 (Polyoquine ethylene glycol nonylphenyl ether manufactured by Daiichi Kogyo Seiyaku ■) 9 and C
) An aqueous solution in which ammonium persulfate 129 was dissolved as a polymerization initiator was added and emulsified for another 30 minutes using a homomixer to obtain a black gray emulsion.

Next, transfer the black gray emulsion to a 3F four variable flask equipped with a stirrer, nitrogen inlet 17M degrees 84' + condenser, and reduce the temperature of the flask to 7 degrees under nitrogen flow.
After merging at 0° C. for 5 hours and 14 hours, the mixture was cooled to obtain an emulsified mixture. The polymerization rate at this time was 99.5% or more. The molecular weight of the polymer was determined by gel chromatography using a standard polystyrene tapered line, and the weight + 1 average molecular weight (Mw) was 86,000. Ty,
It was determined that the average molecular weight (Mn) was 30,000.

(2) l Soybean analysis process/final process emulsification base liquid 1/(r Mg50 heated to 100℃
While stirring for 7 minutes and maintaining the temperature of the aqueous solution at 100°C, it was uniformly added dropwise to a 40:3 aqueous solution 2E over about 30 minutes to effect salting out. The mixture was kept at this temperature for an additional 30 minutes and cooled to room temperature. Next, this slurry was dehydrated using a centrifugal dehydrator, and then washed three times with warm water at 50°C to make bamboo.

Then, it was dried in a dryer at 30 to 35°C to obtain a toner. When the particle size of the obtained L-ner was measured using a Coulter counter, the particle size was 3 to 80 μm, and the average particle size Vi was 18 μm.
There are four m″c. Furthermore, the glass transition point (
Tg) was measured and found to be 73°C. This toner was further classified into 5 to 25 μm using a zigzag classifier (100MZR, -/' Rubino), and the yield was 90 as measured by χJ before classification. Also in the following Examples and Comparative Examples, the ladle diameter and average particle diameter were measured using a Coulter counter, the glass transition point was measured using a differential scanning calorimeter, and the first classification was performed using a zigzag classifier.

Examples 2 to 4 and Comparative Examples 1 to 2 The emulsion polymerized Q and 11 obtained in Example 1 were added to an aqueous salting-out agent solution (shown in Table 1) heated to the salting-out temperature shown in Table 1 for about 30 min. It was added dropwise uniformly over a period of minutes to salt out.

During salting out, the above-mentioned salting-out temperature was maintained, and after the emulsion polymerization liquid was added dropwise, the temperature was maintained at the same temperature as the above-mentioned salting-out temperature for 30 minutes, and then cooled to room temperature. The obtained fc salting out (
slurry) is dehydrated using a centrifugal dehydrator.

It was washed three times with warm water at 50'C. Then, it was dried in a 1,.Σ specification at 30 to 35°C to obtain toner particles. Stiff tonneau too! Example 1
It is shown in Table 1 along with the hair condition.

Examples 1 to 4 and specific softness f! Using the classified toner obtained in II-2, a Hokodori paper copying machine (manufactured by Konishiroku Photo Industry ■+' B Ix1600) using an insulating carrier from dJ sales.
) was used to test the properties of C2 electrophotographic toner. However, each toner was treated with external addition of 0.6% and 0.1% of hydrophobic Nrica (R, -972 manufactured by Nippon Aerosil ■) and zinc stearate as fluidity improvers to the above toner, respectively. provided. The test results are shown in Table 1.

￥ Image side 5-7 Emulsion polymerization liquid II obtained in Example 1! and a salting-out agent aqueous solution heated to the salting-out temperature shown in Table 2 (0 in Table 2)
was used for one cycle, and salted out in the same manner as in Examples 1 to 4. The obtained one-sip liquid (slurry) was put into an autoclave and heated for 30 minutes at the heat treatment temperature of the batter 2. After that, it was cooled,
Dehydration, water washing and drying were carried out in the same manner as in Examples 1 to 4 to obtain toners.

Table 2 shows the particle size, average particle size, yield of particles of 5 to 25 μm, and electrophotographic properties tested in the same manner as in Examples 1 to 4 of the obtained toner.

Table 2 Characteristics Example 8 (1) Manufacturing process of emulsion polymerization liquid Grafted carbon 1009. Styrene 3609, butyl methacrylate 1809. Methacrylic acid 69, I-dodecyl mercaptan 0.69 and low molecular weight polypropylene (Viscol 550P, Sanyo Chemical Industries ■ trade name) 69 were mixed and dispersed in a homomixer at 300 Or, p, m for 30 minutes.

Next, 1500 g of ion-exchanged water, 189 g of sodium dodecylbenzenesulfonate. 4 g of nonionic surfactant Nonipol PE-68 (Sanyo Chemical Industry ■ trade name),
Nonionic surfactant Noigen EA] 70 (Dai-Kohin Pharmaceutical ■Product name) 49. An aqueous solution containing 99% of ammonium persulfate and 3g of hydrogen peroxide was added to a homomixer and emulsified for 30 minutes at 300°R, P, In at room temperature to obtain a black pre-emulsion.

This black pre-emulsion is 31! The mixture was transferred to four separable flasks, polymerized at 70° C. for 5 hours under a nitrogen stream, and then cooled to obtain an emulsion polymerization solution.

The polymerization rate at this time was 99.5% or more, and the molecular weight of the polymer obtained in the same manner as in Example 1 was 105.000.
Mn was 41,000.

(2) Salting out process/final process According to the salting-out agent aqueous solution and salting-out temperature shown in Table 3.

Toner particles were obtained in the same manner as in Examples 1 to 4.

Example 9 Emulsion polymerization liquid II obtained in Example 8! Toners were obtained in the same manner as in Examples 5 to 7 using the aqueous salting-out agent solution, salting-out temperature, and heat treatment temperature shown in Table 1, except for the salting-out process and the final process.

Particle size and average particle size of toners obtained in Examples 8 and 9, 5
Table 3 shows the yield of particles of ~25 μm, the glass transition temperature of the main resin component, and the electrophotographic properties tested in the same manner as in Examples 1-4.

1,'',1)i Table 3 Characteristics Example 10 (1) Manufacturing process of emulsion polymerization solution In Example 8, instead of grafted carbon 1009: [Carbon blank (Carbon Planfuna 44. Mitsubishi Chemical An emulsion polymerization solution was obtained in the same manner as in Example 8, except that 3o9 (trade name, furnace blank carbon black) was used, 414 g of carbon black was used, and low molecular weight polypropylene and hydrogen peroxide were not used.

At this time, the polymerization rate was 99% or more. The Mw of the 9 polymer was 90,
000. Mn was 29,000.

(2) Salting-out step/Final step Emulsification 4 [Combined solution 11!1] Table 4 shows the salting-out agent aqueous solution and salting-out temperature, and toners were obtained in the same manner as in Examples 1 to 6.

Examples 11 and 12 Emulsion polymerization liquid II obtained in Example 10! 1 Example 5 was prepared using the salting-out agent aqueous solution, salting-out temperature, and heat treatment temperature shown in Table 4.
A toner was obtained in the same manner as in 7.

Particle size, average molecular edge, 5 to 25 μrη particle size, glass transition point of the main disease n1 component, and electrophotographs of the toners obtained in Examples 10 to 12 in the same manner as in Examples 1 to 4. The characteristics are shown in j(4).

1 Table 4% Example 13 Emulsion polymerization liquid 11 obtained in Example 8! 6% MgSO4 aqueous solution II! The mixture was added dropwise at room temperature while stirring to cause salting out.

The weight ratio of emulsifier/salting-out agent at this time was 1/6.6. A 1% aqueous solution of polyvinyl alcohol 109 was added as a stabilizer to the salted out solution, and the mixture was heat-treated at 100° C. for 30 minutes. Then, it was cooled to room temperature 1.

At this time, the particle size of the particles in the salting out solution is 100 to 500 μm.
Met. After this, it is dehydrated using a centrifugal dehydrator.

It was washed three times with warm water at 50°C and dried in a dryer at 40°C.

The obtained particles were pulverized with a jet mill to an average particle size of 10 μm, and further classified into 5 to 25 μm with a classifier.

The glass transition point of the main resin component of the obtained toner was 76°C.
I failed. Also, the results of testing electrophotographic properties in the same manner as in Examples 1 to 4.

Itl image resolution (1ine/1nch) was 40, image density was 1.1, gradation was 6\, humidity resistance was 15 (%), and durability was ○.

Comparative Example 3 (Production of toner by suspension polymerization) Styrene 70
9I butyl methacrylate 309°grafted carbon 1
59. Thoroughly knead 2g of Be/Zoilver Oxide in a homomixer, add 500g of a 1% aqueous solution of phosphorous e, 3 calcium, and mix for 3000 r, p, m for 30 minutes with a homomixer.
Dispersed for minutes.

This dispersion was transferred to a l/c flask and subjected to suspension polymerization at 80°C for 7 hours. The deal rate was over 99ch. This polymer was dehydrated, washed with an aqueous hydrochloric acid solution having a PL of 2 or less, and then dried to obtain a toner. The Mw of this toner's v11 fat is 110.0
00. Mn was 50.000.

Comparative Example 4 (Production of toner by spray drying after emulsion polymerization) The emulsion polymerization solution obtained in Example 1 was spray dried at a temperature of 110° C. to obtain a toner.

Comparative Example 5 (Crushing method) Styrene/'butyl tutaacrylate-70/30 (weight ratio) 2 molecular weight Mw 70 by solution polymerization using toluene as a solvent
,000 and Mn of 30,000 were prepared, and the toluene was removed by desolvation under reduced pressure to produce a white solid.

This polymer 1.0009 was mixed with 50 g of carbon black and Phthalo/AyuytpHog.

Low molecular weight M polypropylene/(Visco-A 550P).

Sanyo Chemical Industry Co., Ltd. (trade name) 209 (Z) was kneaded with two rolls and pulverized with a jet mill to obtain a toner.

Comparative Example 6 The same procedure as in Example 13 was carried out, except that the step of adding polyvinyl alcohol 1-thi aqueous solution 109 and heat-treating at 100° C. for 30 minutes was omitted.

Particle size and average particle size of toners obtained in Comparative Examples 3 to 6, 5
Table 5 shows the yield of ~25 μm particles, the glass transition temperature of the main resin component, and the electrophotographic properties tested in the same manner as in Examples 1 to 4.
7 toss.

Table 5 Properties Evaluation of electrophotographic properties in Examples 1 to 14 and Comparative Examples 1 to 6 was performed as follows.

fat Resolution: Shigeko Photography Society Test Chart NQ
1 and the respective prepared developers were used to copy onto plain paper. We compared and evaluated whether one elephant could be read in detail 1 of the copied image.

lb) Image quality: Judgment was made by measuring the density of the black part of the copied paper with a densitometer in the same manner as the resolution.

(C1 gradation: Evaluated in the same way as the resolution using the # section divided into 11 steps at the center of the test chart.

fd) Cleaning/cleaning properties: Each of the prepared developers was continuously copied using a copying machine at a temperature of 30° C. and a humidity of 80° RH, and evaluation was made based on the number of copies made until cleaning defects occurred.

le) Blocking property: Examples 1 to 14. The toners prepared in Comparative Examples 1 to 3 were left for 72 hours at 50° C. and 95% humidity, and it was determined whether the toners were blocked.

◎: Very good O: Ambiguous △: Slightly inferior ×: Inferior It was evaluated as

(Charging stability: Stir the prepared developer with a copying machine and set the charging at fixed time intervals 611)
Judging by t change.

◎: Very good O: Disturbed △: Slightly inferior X: Inferior It was evaluated as

(gl Durability: Each prepared developer was tested using a copying machine at a temperature of 30°C, humidity of 80%H, and 1-1 conditions.
Continuous copying of 0.000 sheets was performed. The scattering of toner that occurs at this time was investigated and judged based on the following evaluation.

◎: There is no toner scattering.

O: Slight scattering of toner is observed.

△: There is a lot of toner scattering.

×: A large amount of toner scatters.

(hl Moisture resistance: Each prepared toner was heated to 25°C.
The sample was left for 24 hours at a humidity of 98%, and the ratio of weight increase after humidification to the weight before humidification is expressed as a ratio.

Using the toners obtained in Examples 1 to 14 and Comparative Examples 3 to 6, a plain paper copying machine (N made by Copia Co., Ltd.) using conductive carrier 1 was used.
Table 6 shows the results of tests on resolution 9 image density and gradation pressure in the same manner as the electrophotographic characteristics test described above.

48 (Effects of the Invention) The method for producing an electrophotographic toner according to the present invention makes it difficult to obtain 1 resolution, 9 image density, and 9 gradations.

In particular, it is obtained by legally utilizing an emulsion type toner whose durability and moisture resistance are questionable. Furthermore, in addition to the above characteristics, cleaning 11t, charging stability and blocking property are 1・r.
- It is also possible to obtain a sticky toner.

<1 Continuation of page 1 C inventor Shigeki Tanaka @Inventor Takashi Amano Inside the venue

Claims (1)

[Claims] 1. A main resin component is produced by emulsion polymerizing a polymerizable monomer in the presence of a colorant and/or magnetic powder. It is characterized by salting out the obtained emulsion polymerization liquid at a temperature higher than the glass transition point of the main resin component, or heating the particles obtained after salting out to a temperature higher than the glass transition point of the main resin component. A method for producing toner for electrophotography. 2. The method for producing an electrophotographic toner according to claim 1, wherein at least one compound selected from an inorganic acid, an organic acid, and a water-soluble gold salt thereof is used as a salting-out agent during the salting-out.