JPH02105163A - Production of microcapsule toner - Google Patents

Abstract

PURPOSE:To improve a preservable property and durability together with fixability by adding resin particles electrified to a negative polarity into an aq. dispersion of suspension-granulated particles coated with a positive polarity dispersant to further coat the particles with the resin. CONSTITUTION:The resin compsn. which is electrified to the negative polarity is suspension-granulated in the aq. medium in the presence of the positive polarity dispersant to form the suspension-granulated particles coated with the positive polarity dispersant. The resin particles which are electrified to the negative polarity are charged into the aq. dispersion of the suspension-granulated particles to coat the suspension-granulated particles with the resin particles. The microcapsule toner which obviates the generation of the incomplete films, prevents the shell material from being broken even by the physical and mechanical forces from the outside and does not generate the composite particles is, therefore, obtd. The good fixability is obtd. in this way on ordinary paper and the microcapsule toner which is excellent in both the durability and long-term preservability against repetitive copying is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner used in electrophotography, electrostatic printing, magnetic recording, etc., and particularly relates to a method for producing a microcapsule type toner.

[Conventional technology] Toner that visualizes electrical and magnetic latent images.

It is used in various processes for forming and recording images.

As electrophotographic application technology has become more versatile in recent years, a large number of technological developments have continued to be made in response to the use of toners and developers for forming copied images. Toner is a powder that forms images, but in order to form images accurately, toner particles must have many functions, such as charging properties, transportability, fixing properties, and storage stability. . Generally speaking, there is no single substance that satisfies all of these functions, so toners are usually prepared as a mixture of various materials. In a typical toner production method, a binder resin is used to fix the toner on the transfer material, various colorants are used to give the toner its color, and a charge control agent is used to impart charge to the particles. Publication No. 54-42141,
In the so-called one-component development method as disclosed in Japanese Patent Application Laid-Open No. 55-18858, various magnetic materials are used to impart transportability to the toner itself. When manufacturing toner, in addition to these materials, a release agent and a fluidity imparting agent are dry-mixed as necessary, and then uniformly kneaded while applying heat using a general-purpose kneading device such as a roll mill or extruder. After cooling, it is pulverized using various types of pulverizing equipment such as speed mills and jet mills, and then pulverized using an O9 classifier and M
By classifying the particles using various wind classifiers such as an S classifier, the particle size can be adjusted to the size required for toner. The toner particles thus obtained are dry mixed with a fluidizing agent, a lubricant, etc. as necessary, and when used in the so-called 21&min development method, are mixed with various magnetic carriers, and then used as a toner for image formation. provide

However, in a toner made of a mixture of various materials each having its own capabilities, each function cannot be fully exerted separately.

Even if materials have sufficient functions if separated into individual materials, because they are mixed together, or because of the toner particle form, or materials with a certain function may have other properties that are undesirable as toner particles. 0For example, even if there is a binder resin that has very good fixing properties, the resin has moisture adsorption properties. If it is strong, the toner will have poor charging properties. Even if there is a magnetic material with excellent magnetic properties, if the compatibility between it and the binder resin is poor, the magnetic material will be damaged during pulverization after crosstalk. may become separated by m and the charging characteristics may become unstable.
Alternatively, if a release agent is added to the toner material in an attempt to prevent the offset phenomenon to the fixing roller, the toner particles may become non-uniform and the charging characteristics may also become non-uniform. In addition, the binding material with very good fixing properties is
It also has general properties such as problems with storage stability and durability during repeated use.

As a means to solve such problems, US Pat. No. 4,018,099 and US Pat. No. 3,788.9
A toner particle form called a so-called microcapsule toner, as seen in Japanese Patent No. 94, etc., has been considered. In other words, it is a so-called function-separated toner that fully demonstrates the functions of various materials and has sufficient performance as toner particles.For example, one simple form of microcapsule toner is as follows. I can give you something like this. In other words, the particles are a mixture of a binder resin that has good fixing properties but poor storage stability and durability, and a magnetic material that has good magnetic properties but tends to inhibit the charging properties of the toner. It is used as a material to give toner fixing and transport properties. Then, an outer wall is formed that encloses the mixture particles, and this outer wall, the so-called shell material, has a charging function and core material retention function.
1A function, and the core material is protected by a harder outer wall, so it has excellent durability and storage stability.

Many proposals have been made regarding materials and manufacturing methods for such microcapsule toners.For example, in terms of composition, any material can be considered within a general range, and methods for obtaining microcapsules include spray drying, spray drying, etc. Interfacial polymerization method, core cell base method, phase separation method, 1n-sit
There are various methods such as the u-polymerization method. However, it is not necessarily possible to produce a microcapsule toner having the necessary performance as a toner by the above-described method using materials having various desirable functions.

In other words, in many cases, there are problems such as incomplete formation of the outer wall, that is, defects occur, and even if the shell is attached, it easily peels off due to physical or mechanical force, and problems arise when making microcapsule toner. A problem arises in that the toner particles coalesce and the toner becomes undesirable. Furthermore, there are many cases where materials that are useful for functioning as a normal toner are not necessarily suitable for producing microcapsule toners.

Most microcapsule toners are intended to be so-called pressure fixable toners.

This pressure fixing method is different from conventional fixing methods that use heat chambers or heated rolls; it is a method in which toner particles are attached to the transfer material using mechanical pressure, which reduces energy consumption and fire safety. advantageous in terms of Furthermore, in the case of microcapsule toner, a softer material can be used as the fixing material compared to conventional bare pressure fixing toner, so there is an advantage that the fixing pressure can be lower than before, and the fixing device can also be made smaller. However, if there is incomplete shell formation as in -h,
Because the core material is soft, the core material exposed to the outer surface of the toner or leaked out may cause a so-called fusion phenomenon or flow on the developing sleeve, which is the toner carrier, and the photosensitive drum, which is the latent image carrier. This can lead to poor toner transportability due to decreased toner properties, and non-uniform charging properties can cause fogging and decreased density, leading to decreased toner durability and storage stability. If the particles coalesce, this mixture may be destroyed in the developing device, and the destroyed portion may become a defective film, or the toner coating properties on the developing sleeve may deteriorate, charging properties may be reduced, or unevenness may occur. may cause this to occur. In addition, the presence of free shell material (free shell or free polymer) that is not covered by the core material may reduce the fluidity of the toner, and may cause density reduction or image unevenness due to the accumulation or uneven distribution of unnecessary electrical charges. There is.

In addition, materials with sufficient strength and charging ability or a combination of two or more materials may be used as the outer wall of the capsule toner.
It is not suitable for producing a satisfactory microcapsule toner, and may result in an incomplete microcapsule toner as described above.

In addition, in -component magnetic toner, since the magnetic material that serves as the toner carrier is contained inside the toner particles, the content, distribution, uneven distribution, etc. of the magnetic material particles in each toner particle when finely divided affect the toner performance. For example, if the content of magnetic particles contained in each toner particle is different, the development characteristics of each toner particle will be different, which tends to cause phenomena such as fog on the image, and it is difficult to continuously develop the image. Alternatively, the change in image density during copying becomes large, resulting in significant deterioration in image quality. Additionally, as a result, the fixing performance becomes inconsistent, and the toner coating on the sleeve roller for development tends to become uneven.Furthermore, since some toner particles have a high resin content and some toner particles have a low resin content, the fixing performance becomes inconsistent. or the offset property becomes worse. In addition, if the magnetic particles are not uniformly dispersed in the toner particles, the concentration of the toner particles will decrease, and the toner will tend to stick to the developer sleeve roller, photoreceptor, cleaner, etc., and the toner will be blocked. The phenomenon becomes more likely to occur.

[Problems to be Solved by the Invention] The objects of the present invention are to prevent the formation of an incomplete film, to prevent the shell material from being destroyed even by external physical or mechanical forces, and to prevent the generation of coalesced particles. It is an object of the present invention to provide a method for manufacturing microcapsule toner that does not require the following steps.

Still another object of the present invention is to, according to the intended use of the toner,
An object of the present invention is to provide a method for producing a microcapsule toner in which toner performance can be arbitrarily controlled.

[Means and effects for solving the problem] As a result of intensive research, the present inventor suspended and granulated a negatively charged resin composition in an aqueous medium in the presence of a positive dispersant, thereby forming a positive electrode. After forming suspended granulated particles coated with a dispersant,
The above object of the present invention is achieved by a method for producing a microcapsule toner, which comprises adding negatively charged resin particles to an aqueous dispersion of the suspended granulated particles to coat the suspended granulated particles. The present invention has been based on the discovery that this can be achieved.

The present invention will be explained in more detail below. In the following description, "1%" and "part" expressing a quantitative ratio are based on weight unless otherwise specified.

As the negatively charged resin that becomes the suspended granulated particles (hereinafter referred to as core particles) used in the present invention, there are, for example, resins obtained by polymerizing the following polymerizable monomers.

That is, for example, styrene, 0-methylstyrene,
-Methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2
．． 4-dimethylstyrene, p-n-butylstyrene, p
- Styrene and its derivatives such as tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-F decylstyrene; Ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl vinyl; Vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate Class; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate,
Isobutyl methacrylate, n-octyl methacrylate.

Dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate, acrylic acid n
- Acrylic acid esters such as butyl, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate: vinyl methyl ether , vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylaterile, and acrylamide. be.

During polymerization, polymerization is carried out in the presence of the following crosslinking agent,
It may also be a crosslinked polymer.

Divinylbenzene, divinylnaphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate methacrylate.

! , 8 hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2.2'bis(4-methacryloxyjethoxyphenyl)propane, 2.2'bis(4-acryloxy) (jetoxyphenyl)propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromneopentyl glycol dimethacrylate, general crosslinking agents can be used as appropriate, and these polymerizable monomers In order to charge negatively in an aqueous medium, (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, vinyl benzoate, styrene sulfonic acid, etc. can be copolymerized. can.

In addition, low softening point compounds can also be used for the core material particles of the present invention, such as paraffin wax (manufactured by Nippon Oil Co., Ltd.),
Paraffin wax (Japanese wax type), micro wax (made by Nippon Oil), microcrystalline wax (made by Nippon Seiro), hard paraffin wax (made by Nippon Seiro), polywax 500 (Hetrolite), polywax 6
55 (Hetrolite), PE-130 (manufactured by Hoechst), Mikata Hiwax ll0P (manufactured by Mikata Petrochemical),
Mikata Hiwax 220P (Mikata Petrochemical), Mikata Hiwax 880P (Mikata Petrochemical), Mikata Hiwax 210P (Ei Petrochemical), Mikata Hiwax 320P (Mikata Petrochemical) ), Mikata Hiwax 41
0P (manufactured by Mikata Petrochemical), Mikata Hiwax 420P
(Mikata Petrochemical), Mikata High Wax 4202E
(Mikata Petrochemical), Hilett T-100X (Mikata Petrochemical), Hilett T-200X (Mikata Petrochemical), Hilett T-300X (Mikata Petrochemical); Vetrogin 80 (Mikata Petrochemical) petrochemical), Vetrogin 1
00 (Mikata Petrochemical), Vetrogin 120 (Mikata Petrochemical), Tuckney? , A-100 (manufactured by Mikata Petrochemical), Tac Ace F-100 (manufactured by Mikata Petrochemical),
Tac Ace B-80 (manufactured by Mikata Petrochemicals), modified wax JC-1141 (manufactured by Mikata Petrochemicals), modified wax J
C-2130 (manufactured by Ei Petrochemical), modified ry-, Kusu JC-4020 (manufactured by Mikata Petrochemical), modified wax JC
-1 eye 2 (Mikata Petrochemical), modified wax JC-5
020 (manufactured by Mikata Petrochemical): Examples include beeswax, carnauba wax, and montan wax. In addition, in order to charge to a negative polarity, anionic surfactants such as sodium dodecylbenzenesulfonate, sodium oleate, sodium stearate, etc., or (meth)acrylic acid (co)polymers, maleic acid and α - Olefin copolymers etc. can be mixed and added.

The core material particles of the present invention can contain a magnetic substance, a pigment, a coloring agent such as carbon black, etc. For example, as the magnetic powder used with the above core material resin, fine powders such as various ferrites, hematites, magnetites, etc. is used. Especially 0. These magnetic fine powders, which preferably have a particle size in the range of O1 to 2IL, are used in an amount of 20 to 140 parts, more preferably 5 parts, to 100 parts of the above-mentioned core resin.
It is preferable to use 0 to 120 parts, but the surface may be hydrophobized with a titanium coupling agent, a silane coupling agent, a fatty acid, or the like.

In addition to the magnetic powder described above, carbon black, various dyes and pigments, hydrophobic colloidal silica, etc. may be added to or mixed with the core material particles of the present invention for the purpose of charge control, fluidity imparting, coloring, etc. can.

Examples of the positive polar dispersant used in the present invention include amine-modified colloidal silica, colloidal silica, and amyl oxide.

In the present invention, the negatively charged resin particles (hereinafter referred to as wall material particles) used to coat the surface of the core material particles are manufactured using an emulsion polymerization method, an emulsion polymerization method that does not use an emulsifier, and a so-called soap polymerization method. Wall material particles can also be obtained by free emulsion polymerization.

Further, methods for positively charging the wall material particles in water include, for example, a method of introducing in advance a component that becomes positively polarized in an aqueous medium as a binder resin or a polymerizable monomer polymerization initiator, and a method of charging the wall material particles to positive polarity in water. Examples include a method of attaching or adsorbing a substance exhibiting positive polarity to the surface of the core material particle after production by the above production method, or a method of using the three substances listed in L in combination, which are considered preferable in consideration of the production process. Any method can be used as appropriate.

In addition, known resins can be used as the binder resin for the wall material particles of the present invention, and these resins are generally polymerizable monomers used in suspension polymerization, emulsion polymerization, soap-free polymerization, etc. For example, styrene, 0-methylstyrene, l-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3 .4
-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-ter
t-butylstyrene, p-n-hexylstyrene, p-
n-octylstyrene, p-n-nonylstyrene, p-
n-decylstyrene, p-n-dodecylstyrene, p-
Styrene and its derivatives such as chloromethylstyrene and layer-chloromethylstyrene; ethylenically unsaturated heptanoolefins such as ethylene, propylene, butylene, and isobutylene; halogenated vinyl chloride, vinylidene chloride, vinyl bromide, vinyl strands, etc. Vinyls: Vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate , 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, etc.
Methylene aliphatic monocarboxylic acid esters methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate , acrylic acid 2-
Acrylic acid esters such as chloroethyl and phenyl acrylate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; N-vinylpyrrole; N-vinyl compounds such as N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

During polymerization, polymerization is carried out in the presence of the following crosslinking agent,
It may also be a crosslinked polymer.

Divinylbenzene, divinylnaphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate methacrylate, 1.
8 hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2.2'bis(4-methacryloxyjethoxyphenyl)propane, 2.2'bis(4-acryloxyjetoxyphenyl) (toxyphenyl)propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromneopentyl glycol dimethacrylate, allyl phthalate, 1,2-propylene glycol,
Common crosslinking agents such as 1,3-butanediol can be used as appropriate.

In addition, examples of monomer components that make the wall material particles have negative polarity in an aqueous medium include (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, and vinyl benzoate. , styrene sulfonic acid, etc. can also be copolymerized.

Examples of the polymerization initiator used in polymerizing the wall particles and/or core particles of the present invention include l,1'-azobis(cyclohexane-1-carbonitrile),
2.2'-7zobisisobutyronitrile, 2.2'-azobis(2,4-dimethylvaleronitrile), 2.
Examples include 2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobisisodimethyl acetate, benzoyl peroxide, lauroyl peroxide, potassium persulfate, and ammonium persulfate.

Two or more types of these polymerization initiators can be used in combination. The amount of the polymerization initiator used in the monomer composition is preferably 0.1 to 10.0 parts.

The wall material particles used in the present invention are used in an amount of 0.1 to 50 parts per 100 parts of the core material particles, more preferably 1 part
This is the case where ~30 parts are used. If the wall material particles are less than 0.1 part, the core material particles will not be encapsulated substantially, and if the wall material particles are 50 parts or more, the core material particles will significantly agglomerate with each other during encapsulation, and the microcapsule toner will not be formed. cannot be used practically.

In the present invention, the particle size ratio of the wall material particles and the core material particles may be between 171,000 and 1/1, more preferably between 11,500 and 1/2, assuming that the particle size of the core particles is 1. This is the case. If the particle size ratio of the wall material particles and the core material particles is smaller than 1/1 (100), that is, if the wall material particles are too small, it is possible to form a capsule wall on the surface of the core material particles. As a microcapsule toner, the durability and storage stability are significantly inferior, and if the size is larger than 1/l, that is, if the wall material particles are too large, even if the wall material particles can adhere to the surface of the core material particles, they will be dense and strong. This also results in significantly lower durability.

The average particle diameter of the core material particles of the present invention may be in the range of 1 to 30 μm, more preferably in the range of 5 to 20 μm.

When covering the core material particles of the present invention with wall material particles (hereinafter referred to as encapsulation), the pi of the aqueous medium must be controlled to promote dissociation of the negative polarity dispersant that coats the surface of the core material particles. is preferred, in which case the pH is adjusted to between 1 and 9, more preferably between 2 and 7. In this case, pi may be stabilized using a buffer solution.

In addition, during encapsulation, the temperature of the aqueous medium is 5℃ ~
It is sufficient that the temperature is between 98°C, and it is preferable that this temperature is set to be the same as or lower than the heat distortion temperature, glass transition temperature, melting point, etc. of the core material particles used for encapsulation.For example, if the core material particles are polymerized. When the resin composition is made of a polymerized polyester monomer, it is preferable to carry out the encapsulation at a temperature of 80°C to 40°C, and when the resin composition is made of a low softening point compound,
Preferably, the encapsulation is carried out at 0°C to 30°C.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Core material particles (1) The mixture of the above-mentioned low softening point compounds was mixed and melted using an MKM mixer (manufactured by Ogawa Seisakusho), and then put into an attritor (manufactured by Mikata Miike Seisakusho) heated to 100°C.
Dispersion was performed at 0 rpm for 1 hour to obtain a molten mixture.

On the other hand, put 20 g of water and 40 g of silica (Aeroseal Cloud 200, manufactured by Nippon Aeroseal Co., Ltd.) as a cationic dispersant into a 20fJ Ajihomo mixer (special machine type), and disperse by heating to 90°C with a heating jacket. It was used as a medium.

2 kg of the molten mixture obtained above was put into this dispersion medium and granulated by stirring at a circumferential speed of 20 shoes/sec. After the granulation was completed, it was poured into cold water.

The mixture was classified using a wet classifier, further filtered, and redispersed in water to obtain a slurry containing 1090% solids.

This was used as the core material particle (1) of the present invention. When the surface of the core material particle was observed using an electron microscope, it was confirmed that the silica used for granulation remained. Incidentally, the volume average particle diameter measured by a Coulter counter was 1009 mm.

The above resin composition and magnetic material were mixed, melt-kneaded using two rolls, and then coarsely pulverized.
209.kg with a TK homo mixer (Tokushu Kika Kogyo type). The autoclave was charged with 1541 water and 25 g of silica as a cationic dispersant (Aeroseal So 200, manufactured by Nippon Aeroseal Co., Ltd.). While stirring, the temperature inside the autoclave was heated to 160° C. and maintained at that temperature for 15 minutes. Next, cooling was performed, and when the internal temperature reached 80° C., the contents were poured into ice water to obtain suspended granulated particles.

The mixture was further classified using a wet classifier, further filtered, and redispersed in water to obtain a slurry containing 15.0% solids. This was used as core material particle (2). When the surface of the core material particle was observed using an electron microscope, it was confirmed that the silica used for granulation remained. Incidentally, the volume average particle diameter measured by a Coulter counter was 11.0 pm.

Core material particles (3) Using an attritor, the above polymerizable monomer mixture was
A monomer composition was prepared by mixing at °C.

10 g of colloidal silica (Aerosil 1200, manufactured by Nippon Aerosil Co., Ltd.) as a cationic dispersant was added to 100,100 O of ion-exchanged water as a liquid dispersion medium.
The monomer composition prepared above was poured into a stainless steel container with a capacity of 2H while stirring for 10 minutes using an RP solution, and the mixture was heated with N2.
The mixture was stirred for 30 minutes at 80°C in an atmosphere at 10.00 Orpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).

The monomer composition was granulated. Thereafter, the monomer composition was polymerized at 60° C. for 10 hours while stirring with a paddle stirring blade.

The mixture was further classified using a wet classifier, filtered, and redispersed in water to obtain a slurry containing 5.0% solids. These are referred to as core material particles (3).

When the surface of the core material particles was observed using an electron microscope, it was confirmed that the silica used for granulation remained. In addition, the volume average particle diameter measured by Coulter counter is Le#L
It was s.

Wall material particles (1)'' were mixed with the polymerizable monomers described above to form a monomer composition 2.0.
kg was prepared.

25.0 g of sodium dodecylbenzenesulfonate as a surfactant was added to 15.1 g of ion-exchanged water and dissolved.

Into a stainless steel container with a capacity of 20 tons, the monomer composition prepared in -1; was poured and stirred at room temperature under N2 atmosphere to obtain an emulsion.Next, 2.0 parts of potassium persulfate was dissolved. The temperature was raised while dropping 1.01% of ion-exchanged water, and the temperature was raised to 80℃.
And so. Thereafter, the reaction was carried out for 8 hours with stirring to polymerize the monomer composition. When the obtained fine particles were observed using an electron microscope, the average particle size was 0.07 pm.

This is referred to as wall material particles (1) of the present invention.

Put ion-exchanged water ILQ into a container of RJ 201,
2.0 parts of potassium persulfate was added and dissolved. Then,
The mixture was heated to 60° C. under a N2 atmosphere, and 2.0 kg of the above polymerizable monomer mixture was added dropwise while stirring. Once the 0 dropwise addition was completed, stirring was continued for an additional 4 hours.

Next, the mixture was heated to 80° C. and stirred for 2 hours to complete the polymerization reaction. When the obtained fine particles were observed using an electronic IA microscope, the average particle size was 0.15 mm.

This is referred to as wall material particles (2) of the present invention.

Capacity 20! ;Pour 13 liters of ion-exchanged water into a L container,
1.5 parts of ammonium persulfate salt was added and dissolved.

Next, the mixture was heated to 70° C. under a N2 atmosphere, and 2 kg of the polymerizable Vta compound mixture described in 1-1 was added dropwise without stirring. When the dropwise addition was completed, stirring was continued for an additional 6 hours to complete the polymerization. When the obtained fine particles were observed using an electron microscope, the average particle size was 0.2 mm.

This is referred to as wall material particles (3) of the present invention.

Wall Material Particles (4) Styrene 90 parts L Ethyl acrylate 10 parts The above polymerizable particles were mixed to prepare 2.0 kg of a monomer composition.

50 g of dodecyltrimethylammonium chloride as a surfactant was added to 15.0 g of ion-exchanged water and dissolved.

The monomer composition prepared above was charged into a stainless steel container with a capacity of 20 tons, and stirred at room temperature under N2 atmosphere to obtain an emulsion. Ion exchange water in which 1.5 parts of dihydrochloride was dissolved 1.
The temperature was raised to 50° C. while adding 0 M dropwise. after that,
The reaction was carried out for 8 hours with stirring to polymerize the monomer composition. When the obtained fine particles were observed using an electronic WJ microscope, the average particle size was 0.11.

This is referred to as wall material particles (4) of the present invention.

Wall material particles (5) L2,2'-7 Zobisisobutyronitrile Place 13 tons of ion exchange water in a 13 volume/20 meter container.

2.0 parts of 2,2'-azobis(2-(2-imidacillin-2-yl)propane) dihydrochloride was added and dissolved under acidic conditions with hydrochloric acid. Then, the mixture was heated to 60°C under N2 atmosphere.
While stirring, 2.0 kg of the above polymerizable monomer mixture was added dropwise. When the dropwise addition was completed, stirring was continued for an additional 4 hours.

Next, the mixture was heated to 80° C. and stirred for 2 hours to complete the polymerization reaction. When the obtained fine particles were observed using an electronic WJ microscope, the average particle size was 0.3 ILm.

This is referred to as wall material particles (5) of the present invention.

Wall material particles (6) Pour 13 parts of ion exchange water into a 20-part container, add 1.0 part of 2,2'-azobis(2-amidinopronoman) dihydrochloride, and dissolve under acidic conditions with hydrochloric acid. did. Next.

The mixture was heated to 60° C. under N2 atmosphere, and 2 kg of the polymerization mixture was dropped into the polymerizable solution while stirring. When the addition was completed, stirring was continued for an additional 6 hours to complete the polymerization. When the obtained fine particles were observed using an electron microscope, ＋
The i-average particle size was 0.1 gm.

This is referred to as wall material particles (6) of the present invention.

Example! A slurry containing 1.5 kg of core material particles (2) was placed in a 20-liter container and stirred at room temperature. First, the pH of the aqueous phase was adjusted so that the silica would dissociate and act as a cation.

1- A fine particle dispersion containing 220 g of wall material particles (1) was added to a suspension dispersion of core material particles (2) under stirring. 1
After continued stirring for an hour, the mixture was heated to 50° C. and kept at that temperature for two sowing periods.

After cooling to room temperature, it was separated from the oven and dried. When the surface of the particles was observed using an electron microscope, it was confirmed that the particles were covered with wall material particles.

This is referred to as 1 microcapsule toner (1).

Example 2 Core material particles (1) 1. A microcapsule toner (2) of finished FJJ was obtained by carrying out the same operation as in Example 1 except that a slurry containing Okg and a fine particle dispersion containing 120 g of wall material particles (3) were used.

In addition, when the surface of the particles was observed using a microscope, it was confirmed that the particles were covered with wall material particles.

Example 3 The microcapsule toner of the present invention ( 3) was obtained.

Furthermore, when the surface of the particles was observed using an electron microscope,
It was confirmed that it was covered with wall material particles.

Comparative Example 1 Core material particles (2) 1.5 kg and wall material particles (1) 22
0 g was taken out in a dry state by freeze-drying,
Using this, the high-speed airflow impact method (Materials Technology, Dan (4)
.

187 (1985)).

This is designated as unreleased II comparison toner (1).

The microcapsule toner (1) of the present invention shown in Example 1
) and Comparative Toner (1) were mixed with hydrophobic silica fine powder, and then an image evaluation test was conducted on 1000 consecutive sheets using a LOP-8 (manufactured by Canon) copying machine.

When the obtained images were observed, the microcapsule toner (1) of the present invention had a high image density and was clear with little fog, but compared to that, the image density of the comparative toner (1) was low from the beginning. As the durability test progressed, the fog decreased significantly and was clearly inferior.

In addition, when the microcapsule toner (1) of the present invention and the comparative toner (1) were left in an environment at a constant 45°C and a blocking test was conducted, it was found that the microcapsule toner (1)
No change was observed with the comparison toner (1).
), the fluidity decreased significantly.

Furthermore, when we investigated the relationship between fixing temperature and fixing performance using an experimental machine with an improved fixing device of LOP-8 and variable fixing temperature, we found that the microcapsule toner (1) of the present invention can be used even at 100°C. It showed sufficient fixing properties.

Comparative Example 2 A comparative toner (2) was obtained in the same manner as in Comparative Example 1 using core material particles (1) and wall material particles (3).

Microcapsule toner (2) of the present invention shown in Example 2
) and comparison toner (2) were mixed with hydrophobic silica fine powder, and then 1,000 consecutive unfixed images were printed using an LBP-8 (Canon FA) copying machine, and FC-9. A fixed pressure image was obtained by modifying the fuser.

Observation of the obtained images revealed that the microcapsule toner (2) of the present invention had a high image density and was clear with little fog, but compared to that, the images of the comparative toner (2) deteriorated as the durability test progressed. The image density was significantly reduced and clearly inferior.

[Effects of the Invention] As described above, the microcapsule toner produced by the production method of the present invention has good fixing properties even on plain paper, and has good fixing properties, durability against repeated copying, and good long-term storage stability. It is possible to obtain a microcapsule toner that is compatible with both of the following, and furthermore, an incomplete film does not occur, the shell material is not destroyed by external physical or mechanical force, and coalesced particles are generated. It is possible to provide a method for producing a microcapsule toner that does not require the use of microcapsules.

Claims (1)

[Claims] A negatively charged resin composition is suspended and granulated in an aqueous medium in the presence of a positive dispersant to form suspended granulated particles coated with the positive dispersant. A method for producing a microcapsule toner, which comprises adding negatively charged resin particles to an aqueous dispersion of suspended granulated particles to coat the suspended granulated particles.