JP2004294467A - Thin film coated polymerized toner and method for manufacturing thin film coated polymerized toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reconcile the low blocking property and low-temperature fixation of a polymerized toner and a polymerized and agglomerated toner, to achieve satisfactory anti-blocking property and to reconcile a low fixing temperature and low locking property, particularly by coating the surfaces of a polymerized toner and a polymerized and agglomerated toner having a low softening temperature, without considerably raising the softening temperature, and to attain fixation at a sufficiently low fixing temperature, to reduce thermal energy required for fixation, to shorten fixing time and to attain energy saving and speeding up in a fixing step by using the resulting surface-coated polymerized toner and surface-coated polymerized and agglomerated toner having a low softening temperature and low locking property. <P>SOLUTION: This invention provides a toner obtained by surface-coating the primary particles of a polymerized toner with a thin film containing a thermosetting resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polymerized toner coated with a thin film of a thermosetting resin, particularly a toner suitable for a heat fixing method.
[0002]
[Prior art]
The toner used in the electrophotographic method is roughly classified into a pulverized toner and a polymerized toner. The pulverized toner is manufactured by melt-kneading various components of the toner with a binder resin, pulverizing, classifying, and forming fine particles. The polymerized toner is produced by polymerizing a monomer by a method such as emulsion polymerization, suspension polymerization, or dispersion polymerization to produce a fine particle-like binder resin containing various components of the toner.
[0003]
Among them, recently, a number of proposals have been made to use toners produced by a polymerization method, and polymerized toners are being put into full-scale practical use because they have excellent performance as an electrophotographic developer. . Further, it has been proposed in Patent Documents 1 and 2, for example, that toner primary particles produced by a polymerization method are further aggregated to form toner secondary particles as an association body and used. The polymerized and aggregated toner thus obtained also has excellent performance as an electrophotographic developer, and is being put to practical use.
[0004]
As a fixing method of a developer containing these toners, a contact heating method using a heating roll, a non-contact heating method such as a flash fixing method, a contact pressure method using a pressure roll, a contact pressure method using a heating and pressure roll, etc. A heating and pressurizing method has been proposed and put to practical use.
[0005]
Among these fixing systems, in a heating fixing system such as a contact heating system, a non-contact heating system, and a contact heating and pressurizing system, the fixing temperature is mainly determined by the softening temperature of the toner. If the softening temperature of the toner is sufficiently low, the fixing temperature can be sufficiently lowered, and if the fixing temperature is sufficiently low, the heat energy required for fixing can be reduced and the fixing time can be shortened. Can be realized. From such a viewpoint, for example, a low melting point toner having a low softening temperature has been developed.
[0006]
[Patent Document 1]
JP 05-265252 A
[Patent Document 2]
JP-A-06-329947
[0007]
[Problems to be solved by the invention]
However, when a toner having a low softening temperature is used, the toners tend to agglomerate easily, the transportability is reduced, and blocking tends to occur.
[0008]
On the other hand, when a toner having a high softening temperature is used, the blocking property is low and the transportability is good, but, for example, in the case of a heated roll fixing method, the fixing temperature needs to be sufficiently high to realize sufficient fixing. There is. Further, since it is necessary to secure a sufficient time for the support to which the toner adheres to pass through the nip, it may take a long time for fixing. Furthermore, in order to achieve high-speed fixing by the flash fixing method, it is necessary to irradiate high-intensity flash light, which consumes a large amount of energy and may deteriorate the support, and there is a technical limit to speeding up. there were.
[0009]
As described above, it is generally difficult to achieve both low cohesion (anti-blocking property or low blocking property) and high-speed fixing property of the toner, and this tendency is the same for the polymerized toner. Therefore, in spite of the fact that the polymerized toner has high performance, problems may occur, and the performance of the polymerized toner may not be fully utilized.
[0010]
Also, in the case of the polymerized aggregated toner, it is generally difficult to achieve both low aggregation property (anti-blocking property or low blocking property) and high-speed fixing property, and although the polymerized aggregated toner has high performance, In some cases, problems may occur, and the performance of the polymerized and aggregated toner may not be fully utilized.
[0011]
In view of such circumstances, an object of the present invention is to achieve both low aggregation (anti-blocking property or low blocking property) and low-temperature fixing of a polymerized toner.
[0012]
In particular, by coating the surface of the polymerized toner having a low softening temperature, it is possible to realize a sufficient anti-blocking property without significantly increasing the softening temperature, and to achieve both a low fixing temperature and a low locking property. .
[0013]
As described above, by using a polymerized toner having a low softening temperature and a low rocking property, it is possible to achieve fixing at a sufficiently low fixing temperature, reduce heat energy required for fixing, shorten a fixing time, and save energy in a fixing process. And speeding up.
[0014]
Another object of the present invention is to achieve both low aggregation (anti-blocking or low blocking) and low-temperature fixing of the polymerized aggregation toner.
[0015]
In particular, by coating the surface of the polymerized and aggregated toner having a low softening temperature, it is possible to realize sufficient anti-blocking properties without significantly increasing the softening temperature, and achieve both a low fixing temperature and a low locking property with the object of the present invention. I do.
[0016]
In this way, by using a polymerized and aggregated toner having a low softening temperature and a low rocking property, fixing at a sufficiently low fixing temperature is realized, heat energy required for fixing is reduced, a fixing time is shortened, and a fixing process is performed. Realize energy saving and high speed.
[0017]
[Means for Solving the Problems]
According to the present invention for achieving the above object, there is provided a toner in which primary particles of a polymerized toner are surface-coated with a thin film containing a thermosetting resin.
[0018]
As shown in FIG. 1, the polymerized toner having such a surface coated with a thermosetting resin film is obtained by polymerizing a toner raw material containing a binder resin monomer, which is a raw material of the binder resin, to form toner primary particles 11. Preparing a dispersion of
Mixing a thermosetting resin precursor with the toner primary particle dispersion;
A step of forming the thermosetting resin precursor into a resin without melting the toner primary particles and coating a thin film 31 containing the thermosetting resin on the surface of the toner primary particles;
Can be produced by a method comprising:
[0019]
Further, there is provided a toner in which toner secondary particles mainly composed of aggregates of polymerized toner primary particles are surface-coated with a thin film containing a thermosetting resin.
[0020]
As shown in FIG. 2, the polymer-aggregated toner whose surface is covered with a thermosetting resin film is obtained by polymerizing a toner raw material containing a binder resin monomer which is a raw material of the binder resin and forming toner primary particles. Preparing a dispersion of 10;
Aggregating the toner primary particles to prepare a dispersion of toner secondary particles 20;
Mixing a thermosetting resin precursor with the dispersion of the toner secondary particles;
Forming a thin film 30 containing the thermosetting resin on the surface of the toner secondary particles by resinifying the thermosetting resin precursor without melting the toner secondary particles; and
Can be produced by a method comprising:
[0021]
Here, “melting” refers to a case where the toner is completely melted or liquefied by heating, and does not include softening and thermal deformation. This is because, even if the toner is partially melted by heating, if the degree of softening and deformation of the toner is at a level, a film can be formed on the surface of the toner.
[0022]
The term “resinification” includes not only complete polymerization with a sufficiently high degree of polymerization but also partial resinization with a medium degree of polymerization, which is a degree to which fusion between toners is hindered. Means to form a polymer having a degree of polymerization of
[0023]
By coating the surface of the polymerized toner and the polymerized aggregation toner having a sufficiently low softening temperature with a thermosetting resin, sufficient anti-blocking properties are realized without significantly increasing the softening temperature, and a low fixing temperature and a low locking property are obtained. A compatible surface-coated polymerized toner and surface-coated polymerized toner can be realized.
[0024]
Specifically, the increase in the fixing temperature by coating the surface of the toner with a thermosetting resin can be suppressed to preferably 20 ° C. or less, more preferably 15 ° C. or less, and further preferably 10 ° C. or less.
[0025]
Further, the fixing temperature of the finally obtained thin film-coated toner can be set to preferably 145 ° C. or lower, more preferably 125 ° C. or lower, and further preferably 100 ° C. or lower.
[0026]
By using such a surface-coated polymerized toner and a surface-coated polymerized toner capable of achieving both a low fixing temperature and a low rocking property, it is possible to achieve fixing at a sufficiently low fixing temperature and reduce heat energy required for fixing. The fixing time can be shortened, and energy saving and speeding up of the fixing process can be realized.
[0027]
More specifically, in a contact heating method using a heating roll or the like, a non-contact heating method such as a flash fixing method, a heating fixing method such as a contact heating / pressing method using a heating / pressing roll, or the like, at a sufficiently low fixing temperature. Fixing can be realized, heat energy required for fixing can be reduced, fixing time can be shortened, and energy saving and speeding up of the fixing process can be realized.
[0028]
In order to realize sufficient anti-blocking properties, it is preferable that the surface of the toner is covered with a substantially continuous thin film. Here, “substantially continuously” means that, for example, a powdery coating material is not in a state in which the coating material is fused and coated. It means that it does not exist, and such a surface coating can be confirmed using an electron microscope or the like. In addition, simply, it can be confirmed that the contained toner does not substantially leak.
[0029]
A substantially continuous coating can be formed by resinifying the raw material on the solid surface. For this reason, it is preferable that the toner before being coated with the thin film is a powder at room temperature, and is also a powder when the surface film is formed.
[0030]
Specifically, a thermosetting resin precursor is mixed with a powdery toner dispersion, and the thin film is coated on the surface of the toner by converting the thermosetting resin precursor into a resin without melting the powdery toner. .
[0031]
Since a thin-film thermosetting resin wall is provided on the surface of the toner, even in the case of a toner having a low softening temperature, aggregation of the toners can be suppressed by forming a thin-film coating on the surface.
[0032]
In the case of a polymerized toner manufactured by a method such as emulsion polymerization, suspension polymerization, or dispersion polymerization, the polymerized toner is separated before the coating step by manufacturing the polymerized toner and subsequently coating the surface of the polymerized toner with a thermosetting resin. Since there is no need for purification, good productivity and performance can be realized.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0034]
(Polymerized toner)
The primary particles of the polymerized toner can be prepared by an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, or the like. These polymerization methods use a radically polymerizable ethylenically unsaturated monomer and a radical polymerization initiator and proceed in a suitable medium in the presence of a dispersant as needed.
[0035]
As the polymerization initiator, a water-soluble initiator is used in emulsion polymerization, and an oil-soluble initiator is used in suspension polymerization and dispersion polymerization. Examples of the water-soluble initiator include persulfates (eg, potassium persulfate and ammonium persulfate), water-soluble azo initiators (4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis ( 2-amidinopropane) dihydrochloride and the like, and water-soluble peroxide compounds (hydrogen peroxide and the like). Examples of the oil-soluble initiator include oil-soluble azo initiators (2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), etc.), oils and the like. A soluble peroxide compound (such as benzoyl peroxide) is used. Further, these initiators can be used as a redox initiator in combination with a reducing agent. As the reducing agent, sodium metabisulfite, ferrous chloride, ascorbic acid and the like are used.
[0036]
Examples of the dispersant include surfactants of low molecular weight compounds (anionic, cationic and nonionic) and surfactants of high molecular weight compounds (anionic, cationic and nonionic) such as polyvinyl alcohol, polyvinylpyrrolidone, and hydroxy. Alkyl cellulose or the like is used. Further, as the colloidal inorganic compound, tricalcium phosphate, colloidal silica, colloidal alumina or the like is used. In particular, as a dispersant for suspension polymerization, tricalcium phosphate which is easily removed after the formation of particles is preferable.
[0037]
Examples of the monomer include styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene, o-chlorostyrene, p-methoxystyrene, o-methoxystyrene, p-ethoxystyrene, p-butoxystyrene, Styrene compounds such as 4-dimethylstyrene, 2,4-dichlorostyrene, p-chloromethylstyrene, o-chloromethylstyrene, p-hydroxystyrene, o-hydroxystyrene; methyl (meth) acrylate, (meth) Ethyl acrylate, 2-ethylhexyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, methyl (meth) methacrylate, (Meth) propyl methacrylate, isobutyl (meth) methacrylate, ) Acrylic compounds such as n-butyl methacrylate, 2-ethylhexyl (meth) methacrylate, dodecyl (meth) methacrylate, and stearyl (meth) methacrylate; nitrile monomers such as acrylonitrile and methacrylonitrile; vinyl Vinyl ether monomers such as methyl ether and vinyl ethyl ether; vinyl ester monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; butadiene, isoprene, chloroprene, dimethylbutadiene and the like Conjugated dienes or the like.
[0038]
Further, a monomer having a dissociating group can also be used. Examples of the dissociating group include a carboxyl group, a sulfonic acid group, a phosphoric acid group, an amino group (including a primary amine, a secondary amine, and a tertiary amine), and a quaternary ammonium salt. Specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, monoalkyl maleate, monoalkyl itaconate, and the like are used as monomers containing a carboxyl group. Further, as the monomer having a sulfonic acid group, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl methacrylate, salts thereof and the like are used. Further, as a monomer having a phosphate group, acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, 3-chloro-2-acid phosphooxypropyl methacrylate, or the like is used.
[0039]
In addition, amino group acrylic (methacrylic) acid ester, acrylic (methacrylic) acid amide, acrylic (methacrylic) acid amide mono- or di-substituted with an alkyl group having 1 to 18 carbon atoms on nitrogen, and nitrogen as a ring member Heterocyclic-substituted vinyl compounds, N, N-diallylalkylamines, quaternary ammonium salts thereof, and the like can be used. More specifically, as the acrylic (methacrylic) acid ester, dialkylaminoalkyl (meth) acrylate (for example, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc.) and their acid salts or A quaternary ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt and the like can be used.
[0040]
In addition, acryl (methacrylic) amide, acryl (methacrylic) amide mono- or di-substituted with an alkyl group having 1 to 18 carbon atoms on nitrogen can be used, and specific examples include (meth) acrylamide, N-butyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, piperazyl (meth) acrylamide, N-octadecyl methacrylamide and the like can be used.
[0041]
Specific examples of a vinyl compound substituted with a heterocyclic ring having nitrogen as a ring member, N, N-diallylalkylamine, and quaternary ammonium salts thereof include, for example, vinylpyridine, vinylpyrrolidone, vinylimidazole, Quaternary ammonium salts, N, N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like can be used.
[0042]
Further, monomers having an active halogen such as vinylbenzyl chloride and vinylphenethyl chloride can also be used.
[0043]
In some cases, an appropriate amine is used to form a tertiary amine or a quaternary ammonium salt after the polymerization. Further, it can be copolymerized as a dialkylamine and a quaternary ammonium salt. For example, a dialkylamine can be introduced into vinylbenzyl chloride by reacting it with a monomer or by polymer reaction.
[0044]
Further, if necessary, a crosslinkable monomer such as divinylbenzene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate is used.
[0045]
The weight average molecular weight of the polymer constituting the primary particles of the polymerized toner is generally in the range of 1,000 to 1,000,000.
[0046]
(Polymerized aggregation toner)
The primary particles of the polymerized toner obtained as described above are agglomerated and associated with each other as secondary particles of the polymerized toner as necessary, taking into consideration the required performance of the finally obtained toner. A surface coating.
[0047]
Aggregation and association of the polymerized toner primary particles are performed by adding a coagulant such as a water-soluble polymer, acids, alkalis, water-soluble salts, and water-soluble organic solvent to the dispersion of the polymerized toner primary particles. .
[0048]
As the water-soluble polymer, polyvinyl alcohol, modified polyvinyl alcohol, carboxymethyl cellulose, modified carboxymethyl cellulose and the like are used.
[0049]
The amount of the water-soluble polymer to be used is preferably 0.1 part by mass or more based on 100 parts by mass of the dispersion liquid from the viewpoint of sufficiently aggregating the primary particles of the polymerized toner, and from the viewpoint of other properties of the obtained toner. , 50 parts by mass or less.
[0050]
As the acids, organic acids such as acetic acid and acetic acid derivatives; and inorganic acids such as hydrochloric acid and hydrochloric acid derivatives are used.
[0051]
The amount of the acid used is preferably 0.1 parts by mass or more based on 100 parts by mass of the dispersion liquid from the viewpoint of sufficiently aggregating the primary particles of the polymerized toner, and 50 parts by mass from the viewpoint of the other properties of the obtained toner. Parts or less are preferred.
[0052]
As the alkalis, basic organic substances such as ammonia and ammonia derivatives; basic inorganic substances such as sodium hydroxide, potassium hydroxide and calcium hydroxide are used.
[0053]
The amount of the alkali is preferably 0.1 part by mass or more based on 100 parts by mass of the dispersion from the viewpoint of sufficiently aggregating the primary particles of the polymerized toner. It is preferably at most part by mass.
[0054]
Examples of the water-soluble salts include salts containing monovalent metals such as alkali metals such as sodium, potassium and lithium; salts containing alkaline earth metals such as calcium and magnesium, and salts containing divalent metals such as manganese and copper; A salt containing a trivalent metal such as aluminum is used. Specific examples of the salt containing a monovalent metal include sodium chloride, potassium chloride, and lithium chloride. Specific examples of the salt containing a divalent metal include calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Specific examples of the salt containing a trivalent metal include aluminum chloride and iron chloride.
[0055]
The amount of the water-soluble salt to be used is preferably 0.1 parts by mass or more based on 100 parts by mass of the dispersion from the viewpoint of sufficiently aggregating the primary particles of the polymerized toner, and from the viewpoint of other properties of the obtained toner, It is preferably at most 50 parts by mass.
[0056]
As the water-soluble organic solvent, an organic solvent that dissolves in an amount of 0.01 part by mass or more with respect to 100 parts by mass of water at 25 ° C is preferable, and specifically, methanol, ethanol, propanol, isopropanol, butanol, sec-butanol, and isobutanol Pentanol, sec-pentanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, 2,2- Dimethyl-1-propanol, cyclohexanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-methylcyclohexanol, 2-methylcyclohexanol Alcohols such as acetonitrile, propionitrile, succinonitrile , Butyronitrile, isobutyronitrile, nitriles such as benzonitrile; Using the like; methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, pyridine, aniline, amine such as imidazole; acetone.
[0057]
The amount of the water-soluble organic solvent used is preferably 1 part by volume or more, more preferably 5 parts by volume or more, and more preferably 10 parts by volume or more, based on 100 parts by volume of the dispersion liquid, from the viewpoint of sufficiently aggregating the primary particles of the polymerized toner. Is more preferred. In addition, from the viewpoint of the other properties of the obtained toner, the content is preferably 200 parts by volume or less, more preferably 100 parts by volume or less, and still more preferably 80 parts by volume or less.
[0058]
The above-described coagulants may be used in combination of two or more as necessary.
[0059]
Further, after preparing the polymerized toner secondary particles, the obtained polymerized toner secondary particles may be heated. By heating the polymerized toner secondary particles formed by the addition of the coagulant, the polymerized toner primary particles are fused and the polymerized toner secondary particles that are more strongly aggregated can be produced. Further, by heating the secondary particles of the polymerized toner formed by adding the coagulant, the primary particles of the polymerized toner are softened, and the shape of the secondary particles of the polymerized toner can be shaped.
[0060]
From such a viewpoint, the heating temperature of the heat treatment is preferably in the range of −10 to + 50 ° C. of the glass transition temperature (Tg) of the polymer constituting the primary particles of the polymerized toner.
[0061]
(Thermosetting resin)
The thermosetting resin to be coated with a thin film is not particularly limited as long as it can produce a high-performance toner.However, since a film is formed on a solid toner, the resin raw material is introduced into the reaction field only from the aqueous medium side. It can be manufactured by the supply method. Specifically, a film produced by an in situ polymerization method, a liquid curing coating method, a coacervation method, or the like is preferable, and a film produced by an in situ polymerization method is preferable from the viewpoint of reactivity and the like. In the in situ polymerization method, a raw material for a resin film exists only in an aqueous medium, and this raw material reacts on fine particles to form a resin, and a film is formed.
[0062]
The type of the thermosetting resin is not particularly limited as long as it is formed by the above-described method, but melamine-based, urea-based urea-resorcinol-based urea-based resins, and the like, because of the excellent performance of the obtained thin film. Urea-based, amide-based, olefin-based, gelatin / gum arabic-based, etc. are used, and urea-based such as melamine-based and urea-resorcin-based are preferable because of low water absorption and excellent storage stability. Since melamine-based resins and urea-based resins such as urea resorcinol have low water absorption, the thin-film-coated toner is prevented from binding when the thin-film-coated toner is dried, and the average particle size and particle size distribution of the toner are reduced. It can suppress the change and does not rot during storage.
[0063]
Specifically, when the coating thin film is made of a melamine resin, the coating thin film can be made by an in situ polymerization method using a methylolated melamine compound.
[0064]
When the coating thin film is formed from a urea resin, it can be formed by an in situ polymerization method using a methylolated urea compound.
[0065]
When the coating thin film is formed from a urethane resin, it can be formed by an in situ polymerization method using an amino-carbonyl monooxy compound.
[0066]
When the coating thin film is made of an amide resin, it can be made by an in situ polymerization method using an amino acid derivative or the like.
[0067]
When the coating thin film is made of an olefin resin, the coating thin film can be made by an in situ polymerization method using ethylene, propylene, styrene, (meth) acrylic acid, (meth) acrylate, vinyl acetate, styrene-divinylbenzene, or the like. .
[0068]
Although the above includes resins other than the thermosetting resin, these non-thermosetting resins can be used if necessary.
[0069]
In particular, a urea-based resin is preferred as the thermosetting resin because the fixing temperature does not greatly increase even when a surface coating is formed. The urea-based resin can be formed by resinifying a concentrated urea-based resin precursor and a urea-based resin precursor mixture.
[0070]
The concentrated urea-based resin precursor refers to one obtained by partially condensing at least one of urea and a urea derivative with at least one of formaldehyde and a formaldehyde derivative to adjust a resin component to a predetermined concentration.
[0071]
From the viewpoint of the performance of the obtained urea-based resin-coated toner, it is preferable to partially condense urea and formaldehyde.
[0072]
From the viewpoint of realizing a sufficient anti-blocking property with respect to 1 mol part of at least one of urea and urea derivative, at least one of formaldehyde and formaldehyde derivative is used as the charge ratio at the time of partial condensation. It is preferably at least 5 mol parts, more preferably at least 1.7 mol parts, even more preferably at least 1.8 mol parts. On the other hand, from the viewpoint of realizing sufficient low-temperature fixability, the amount is preferably 2.5 mol parts or less, more preferably 2.3 mol parts or less, even more preferably 2.2 mol parts or less.
[0073]
In addition, the concentration of the resin component after the partial condensation is preferably 50% by mass or more, more preferably 55% by mass or more, from the viewpoint of achieving sufficient anti-blocking properties, while the viewpoint of achieving sufficient low-temperature fixability. Therefore, the content is preferably 70% by mass or less, more preferably 65% by mass or less.
[0074]
The urea-based resin precursor mixture contains at least one of urea and a urea derivative, and at least one of formaldehyde and a formaldehyde derivative.
[0075]
If necessary, urea, a urea derivative, formaldehyde, and a co-condensation type urea-based resin obtained by co-condensing a monomer component other than the formaldehyde derivative may be preferable.
[0076]
As the co-condensation component, aromatic dihydric alcohols such as hydroquinone, resorcin, dihydroxynaphthalene and bisphenol are used.
[0077]
Above all, non-colored co-condensation components are preferred, and from this viewpoint, hydroquinone, dihydroxynaphthalene, bisphenol and the like are preferred. A urea-based resin surface coating produced using these co-condensation components is preferable because it is stable in the toner coating step and the fixing step and has little coloring.
[0078]
The average thickness of the surface coating of the thin film formed on the toner surface is preferably 0.005 μm or more, more preferably 0.01 μm or more, and further preferably 0.02 μm or more, from the viewpoint of achieving sufficient performance as the surface coating. On the other hand, from the viewpoint of suppressing an increase in the fixing temperature due to the formation of the surface coating, the thickness is preferably 0.1 μm or less, more preferably 0.08 μm or less, and still more preferably 0.05 μm or less.
[0079]
The thickness may be set to 1 μm or less or 0.5 μm or less as necessary for reasons such as required performance of the toner.
[0080]
(Shape of toner)
When a sufficiently thin film is formed on each toner by the thermosetting resin, the average particle size and the particle size distribution of the toner before coating and the average particle size and the particle size distribution of the toner after coating are compared. The differences are slight.
[0081]
The volume average particle diameter of the toner before coating is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, from the viewpoint of the overall performance of the toner, and on the other hand, from the viewpoint of image resolution. Therefore, it is preferably 20 μm or less, more preferably 15 μm or less, and still more preferably 10 μm or less.
[0082]
Similarly, the volume average particle diameter of the coated toner is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, from the viewpoint of the overall performance of the toner. From the viewpoint of resolution, it is preferably 20 μm or less, more preferably 15 μm or less, and still more preferably 10 μm or less.
[0083]
Further, the shape of the toner can be adjusted by heating the toner having the thin film coated on the surface thereof in a temperature range in which the thin film is not thermally broken.
[0084]
Specifically, the surface-coated toner is heated in a temperature range in which the thermosetting resin is not thermally broken and the contained toner components do not substantially leak outside. By this heating, the contained toner component is melted, and the shape of the toner is adjusted and shaped. As a result, the sphericity of the toner is improved, the roundness is improved, and the unevenness on the surface is reduced.
[0085]
Therefore, this heating step can be considered as a step of heating and shaping the toner whose surface is covered with the thin film, and the shape of the toner can be easily and inexpensively and efficiently adjusted to a spherical shape only by heating.
[0086]
The temperature range in which the thermosetting resin is not thermally broken and the contained toner component does not substantially leak to the outside is, for example, preferably equal to or lower than the glass transition temperature of the thermosetting resin, specifically, 95 ° C. The following is preferable, 85 ° C or less is more preferred, and 75 ° C or less is still more preferred. When a toner capable of low-temperature fixing is considered, the temperature is preferably 80 ° C. or lower, more preferably 70 ° C. or lower.
[0087]
On the other hand, from the viewpoint of sufficiently melting the contained toner components and sufficiently shaping the shape of the toner, the temperature range of the heating shaping is preferably equal to or higher than the softening temperature of the toner before the surface coating is formed. The temperature is preferably equal to or higher than the glass transition temperature of the binder resin of the toner. Specifically, the temperature is preferably 35 ° C. or higher, more preferably 40 ° C. or higher, even more preferably 45 ° C. or higher.
[0088]
By heating and shaping, a toner having a sufficiently high sphericity, a sufficiently high roundness, a small surface unevenness, and a surface coated with a thermosetting resin can be produced simply, at low cost, and with sufficient productivity.
[0089]
By using the heat-shaped toner, it is possible to realize sufficient toner transportability and sufficient image resolution.
[0090]
(Thermal properties of toner)
The softening temperature of the toner before coating the surface film is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, and more preferably 40 ° C. or higher, in order to suppress the toner from softening when the toner is coated with the urea-based resin thin film. On the other hand, from the viewpoint of sufficiently lowering the fixing temperature and realizing high-speed fixing, the temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, still more preferably 100 ° C. or lower, and sometimes 80 ° C. or lower. is there.
[0091]
From the viewpoint of realizing a sufficient anti-blocking property, the fixing temperature of the toner before coating the surface film is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, and still more preferably 60 ° C. or higher. From the viewpoint of lowering the temperature and realizing high-speed fixing, the temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, further preferably 100 ° C. or lower, and sometimes 80 ° C. or lower.
[0092]
Further, from the same viewpoint as described above, the glass transition temperature (Tg) of the polymer constituting the toner is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, still more preferably 30 ° C. or higher, while 90 ° C. or lower. Preferably, it is 80 ° C. or lower, more preferably 70 ° C. or lower.
[0093]
(Color material)
The coloring material is not particularly limited as long as it can be added at the time of polymerization of the toner or after the polymerization and can sufficiently color without deteriorating the properties of the toner. Carbon blacks such as channel carbon and furnace carbon; Azo pigments such as fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, and para brown; phthalocyanine pigments such as copper phthalocyanine and metal-free phthalocyanine; flavantron yellow, dibromoanthrone orange, perylene red, and quinacridone A condensed polycyclic pigment such as red or dioxazine violet; a disperse dye, an oil-soluble dye, or the like may be used, and a plurality of coloring materials may be used in combination as needed.
[0094]
Moreover, clay minerals such as calcium carbonate, precipitated barium sulfate, barite powder, white carbon, silica, alumina white, aluminum hydroxide, and kaolin clay, and extenders such as talc, mica, and nepheline cyanite can also be used.
[0095]
In the case of a black toner, carbon black, a magnetic material, a color material mixed with a yellow color material, a magenta color material, and a cyan color material and toned to black are used as the black color material.
[0096]
For a color image, a yellow toner, a magenta toner, a cyan toner, and the like are produced.
[0097]
As the yellow coloring material, a condensed azo compound, an isoindolinone compound, an anthraquinone compound, an azo metal complex, a methine compound, an allylamide compound, or the like is used. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 and the like. I. A dye such as Solvent Yellow 93, 162, 163 may be used in combination.
[0098]
As the magenta coloring material, a condensed azo compound, a diketopyrrolopyrrole compound, an anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound, a perylene compound, and the like are used. . Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48: 3, 48: 4, 57: 1, 81: 1, 144, 146, 166, 169, 177, 184, 185, 202 , 206, 220, 221 and 254 are used.
[0099]
As the cyan coloring material, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like are used. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62 and 66, etc. are used.
[0100]
In the case of a white toner, titanium oxide, titanium white, zinc oxide, zinc white, zinc sulfide, lithopone, lead white, antimony white, zirconia, zirconia oxide and the like are used as white color materials.
[0101]
The ratio of the color material to the whole toner is usually 1 to 20% by mass.
[0102]
(Charge control agent)
The charge control agent is not particularly limited as long as the charge can be sufficiently controlled without deteriorating the properties of the toner, and a negative charge control agent and a positive charge control agent are used.
[0103]
Specific examples of the negative charge control agent include organometallic compounds, chelate compounds, monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acid-based metal compounds, aromatic hydroxycarboxylic acids, and aromatic hydroxycarboxylic acids. Mono- and polycarboxylic acids and their metal salts, their anhydrides, their esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts , Calixarenes, silicon compounds, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic-sulfonic acid copolymers, and nonmetal carboxylic acid compounds. Accepting dyes, electron accepting organic complexes, Phthalocyanine sulfonylamine, chlorinated paraffin, and the like are preferable.
[0104]
Specific examples of the positive charge control agent include nigrosine, a modified product of a fatty acid metal salt, a guanidine compound, an imidazole compound, tributylbenzine ammonium-1-hydroxy-4-naphthosulfonate, and tetrabutylammonium tetrafluoroborate. Quaternary ammonium salts, onium salts such as phosphonium salts, and lake pigments of quaternary ammonium salts or onium salts, triphenylmethane dyes, and these lake pigments (for example, phosphotungstic acid, phosphomolybdic acid, Phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide), higher fatty acids, metal salts of higher fatty acids, dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Diorganotin oxides etc., dibutyl tin borate, dioctyl tin borate, and the like diorgano tin borate such as dicyclohexyl tin borate is present, electron-donating nigrosine dyes, etc. quaternary ammonium salts are preferred.
[0105]
The ratio of the charge control agent to the whole toner is usually 0.01 to 10% by mass.
[0106]
(Carrier component)
In general, there are two-component and one-component developers. The toner used in the two-component system is produced using a binder resin, a coloring material, a charge control agent, a release agent, a surface treatment agent, and the like, and mixed with a carrier to form a two-component developer.
[0107]
On the other hand, in the case of a one-component developer, a carrier component is compounded in a toner in addition to a binder resin, a coloring material, a charge control agent, a release agent, a surface treatment agent, and the like. . Since the toner for a one-component developer contains a carrier component, the toner has a higher density than the toner for a two-component developer. Therefore, when the thin-film-coated toner is recovered by the sedimentation method after washing the thin-film-coated toner, a high sedimentation speed of the thin-film-coated toner can be realized, so that the recovery can be performed well and the dispersant and the like can be easily removed. .
[0108]
From such a viewpoint, as the carrier component, iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, Metals such as beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium; alloys, oxides and mixtures thereof of these metals are used. Metal powders such as oxidized iron powder, nickel powder, copper powder, zinc powder, cobalt powder, manganese powder, chromium powder, rare earth powder; oxide powders of these metals; alloy powders of these metals; oxidation of these alloys Material powder; ferrite powder; magnetite powder and the like are added at 1 to 60% by mass based on the whole toner.
[0109]
The toner is mixed with a carrier as needed. Mixing is performed using a V blender or the like.
[0110]
In the case of a wet toner, the toner component and the carrier liquid are charged into a mixer such as a ball mill and an attritor, sufficiently dispersed, and the mixing step and the granulating step are performed simultaneously.
[0111]
(Formation of surface coating)
In the step of coating a thin film on the toner surface, it is important to select a dispersant in order to realize good thin film coating. The dispersant is selected from the viewpoint of sufficiently dispersing the toner, sufficiently promoting resinification on the toner surface, and sufficiently removing the dispersant in the washing step after the formation of the thin film. If the dispersant cannot be sufficiently removed in the washing step, the thin-film-coated toner may be bound by heating and drying after washing the thin-film-coated toner. When the thin film-coated toner is bound, the average particle diameter and the particle size distribution of the toner are disturbed, and when the bound thin-film-coated toner is forcibly crushed, the film may be peeled off.
[0112]
An anionic dispersant having a carboxyl group or the like is preferable from the viewpoint of sufficiently dispersing the toner and sufficiently promoting resinification on the toner surface. From the viewpoint of sufficiently removing the dispersant in the washing step after the formation of the thin film, the molecular weight of the dispersant is preferably 500,000 or less.
[0113]
More specifically, a high molecular compound having a weight average molecular weight of 500,000 or less and a low molecular compound having a molecular weight of 10,000 or less are preferable. Further, in the case of a high molecular compound, the weight average molecular weight is more preferably 100,000 or less, further preferably 10,000 or less, and in the case of a low molecular compound, the molecular weight is more preferably 1,000 or less.
[0114]
As an index of the molecular weight of the dispersant, the solution viscosity of a 25% by mass aqueous solution of the dispersant at 25 ° C. is preferably 500 mPa · s or more, more preferably 1,000 mPa · s or more, and further preferably 2,000 mPa · s or more. Preferably, on the other hand, it is preferably at most 100,000 mPa · s, more preferably at most 50,000 mPa · s, even more preferably at most 30,000 mPa · s.
[0115]
Further, the concentration of the dispersant in the mixture in the coating step by the resinification reaction is preferably 0.1% by mass or more from the viewpoint of sufficiently dispersing the toner and sufficiently progressing resinification on the toner surface. From the viewpoint of sufficiently removing the dispersant in the washing step after the formation of the thin film, the content is preferably 15% by mass or less, more preferably 12% by mass or less, and still more preferably 10% by mass or more. It is more preferably at most 5% by mass, and sometimes at most 5% by mass.
[0116]
When a high molecular weight dispersant is used, the concentration of the dispersant is reduced. For example, when a dispersant having a weight average molecular weight of 100,000 to 1,000,000 is used, or when the solution viscosity of a 25% by mass aqueous solution at 25 ° C. is 100,000 to 1,000,000 mPa · s, a resin-forming reaction is performed. In the coating step, the concentration of the dispersant in the mixture is, for example, 0.01 to 0.1% by mass. However, it may be 5% by mass or less.
[0117]
Examples of the type of the dispersant include poly (oligo) (meth) acrylic acid, styrene-maleic anhydride copolymer and oligomer partially hydrolyzed ring-opened product (ring-opening ratio is preferably 30 to 80%), styrene -Completely hydrolyzed ring-opened product of maleic anhydride copolymer and oligomer, Partially hydrolyzed ring-opened product of ethylene-maleic anhydride copolymer and oligomer (ring opening ratio is preferably 30 to 80%), ethylene -Completely hydrolyzed ring-opened products of maleic anhydride copolymers and oligomers, partially hydrolyzed ring-opened products of isobutylene-maleic anhydride copolymers and oligomers (ring opening ratio is preferably 30 to 80%), isobutylene -Completely hydrolyzed ring-opened products of maleic anhydride copolymers and oligomers, poly and oligo vinyl alcohols, hexa Oligomers derived from tilcellulose, oligomers derived from methylcellulose, oligomers derived from carboxymethylcellulose, alkylbenzene sulfonates such as sodium benzenesulfonate and sodium dodecylbenzenesulfonate, polyoxyethylene sulfate, etc. can be used. The above may be used in combination.
[0118]
Here, in order to suppress the rapid progress of the resinification reaction, the temperature at which the toner is dispersed and the temperature at which the raw materials of the resin thin film are mixed are set lower than the resinization reaction temperature at which the raw materials are resinified to form a coating. It is preferable that the resinification reaction temperature is gradually increased. Specifically, the dispersion temperature and the mixing temperature are preferably from 10 to 40 ° C, and the resination reaction temperature is preferably at least 30 ° C, more preferably at least 40 ° C, still more preferably at least 50 ° C, and preferably at most 100 ° C. , 90 ° C. or lower, more preferably 80 ° C. or lower.
[0119]
Further, in order to prevent the resinification reaction from abruptly progressing, the mixture for the resinification reaction is preferably weakly acidic, and specifically, has a pH of about 3 to 6.
[0120]
The thin-film-coated toner obtained as described above can be easily recovered by a sedimentation method in a washing step after the coating step, and the dispersant can be easily removed. There is very little to do. Therefore, the thin film-coated toner can be easily crushed after the heating and drying step, and a thin film-coated toner having a desired average particle diameter and a desired particle diameter distribution can be manufactured.
[0121]
(Fixing method)
The method for fixing the thin film-coated toner obtained above is suitable for a contact heating method using a heating roll or the like, a non-contact heating method such as a flash fixing method, a contact heating / pressing method using a heating / pressing roll or the like.
[0122]
In the case of these heating methods, the core toner of the thin film-coated toner is thermally expanded by heating and the thin film coating is destroyed, so that the inner core toner is exposed and fixed to the support. The heat energy at the time of heating is sufficient for the thin film coating to be destroyed, and if an inner core toner having a sufficiently low softening temperature is used, low-energy and high-speed fixing can be realized. In the flash fixing method, since the temperature of the inner core toner is instantaneously increased by the irradiation of infrared rays, the inner core toner expands instantaneously, the thin film coating is instantaneously destroyed, and high-speed fixing can be realized. Further, in the case of the pressurizing method, since the thin film coating is destroyed by the pressure, high-speed fixing to the support can be realized by using the heat fixing method and the flash fixing method together.
[0123]
In the above fixing method, high-speed fixing can be realized with low energy by using a core toner having a low softening temperature.However, since the core toner is coated with a thin film, the core toner having a low softening temperature is used. Also, aggregation of the thin film-coated toners can be suppressed.
[0124]
The fixing temperature of the finally obtained thin film-coated toner is preferably 145 ° C. or lower, more preferably 125 ° C. or lower, further preferably 100 ° C. or lower, from the viewpoints of high-speed fixing and energy saving.
[0125]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Unless otherwise specified, commercially available high-purity reagents were used.
[0126]
(Average particle size)
The average particle diameter of the toner can be calculated by observing the toner with an electron microscope, measuring and averaging the diameter of the toner in the obtained image, and calculating the number average particle diameter and the particle diameter distribution. The volume average particle diameter and the particle diameter distribution can be measured by a method using an orifice, a light scattering method, or the like. In the case of a method using an orifice, the measurement can be performed using, for example, a Coulter Multisider manufactured by Coulter Electronics (UK).
[0127]
(Average thickness of coating thin film)
The average thickness of the thin film coated on the toner can be arithmetically calculated from the average particle diameter of the toner before coating and the average particle diameter of the toner after coating. The measurement can also be performed by fixing the thin film-coated toner in an epoxy resin or the like, cutting the toner, and observing the cross section with an electron microscope. Further, it can be arithmetically calculated from the amount of raw materials consumed in forming the thin film and the average particle diameter of the toner.
[0128]
(Softening temperature)
The softening temperature (° C.) can be measured by a melt extrusion method under a constant pressure. In this method, a predetermined amount of sample is extruded from a nozzle with a constant load while raising the temperature, and the softening temperature is determined based on a temperature at which the predetermined amount of sample flows out or at which the flow speed reaches a predetermined value (flow start temperature). The softening temperature can also be measured by the ring and ball method according to JIS K 7234.
[0129]
(Glass-transition temperature)
The glass transition temperature (Tg, ° C) can be measured by differential scanning calorimetry and dynamic viscoelasticity measurement. The glass transition temperature (Tg) can also be calculated according to the following empirical formula by Fox et al .:
1 / Tg = Σ (1 / Tg _i )
In the equation, Tg _i Is the glass transition temperature of the homopolymer obtained by polymerizing the i-th monomer, and Σ means taking the sum of i.
[0130]
(Image formation)
40 parts by mass of a 0.1% by mass aqueous solution of sodium dodecylbenzenesulfonate (manufactured by Wako Junyaku) and a charge control agent for toner manufactured by Orient Chemical Co. (trade names: BONTRON N-01, BONTRON P-51, BONTRON S-34, (BONTRON E-84) was weighed as 10 parts by mass, 100 parts by mass of glass beads (2 mm in diameter) was added, and the mixture was put into a container with a lid. This is ground for 2 hours with RED DEVIL 5400 (trade name) manufactured by RED DEVIL EQUIPMENT, and then the glass beads are removed with a 150 mesh sieve to prepare a charge control agent dispersion.
[0131]
At the end of the step of washing the toner after coating the thin film, the obtained charge control agent dispersion is added so as to be 0.5% by mass based on the whole mixture. Thereafter, the washing operation is repeated 4 to 5 times to wash the toner, transferred to a stainless steel vat, and then dried for 10 hours in a blow dryer (trade name: FineOven DH-42) manufactured by Yamato Scientific at 40 ° C. .
[0132]
The obtained developer is filled in a toner cartridge of a commercially available copying machine, a solid image is formed, and the toner transportability and the fixability are evaluated.
[0133]
(Example 1-1) Thin film-coated toner 1-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0134]
In 300 parts by mass of the dispersion liquid of the obtained primary particles of the polymerized toner, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of 25% by mass aqueous solution at 25 ° C. has a pH of 4.5 and a concentration of 5% by mass. Was added. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the resulting mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a melamine resin.
[0135]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0136]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0137]
Thereafter, the thin film-coated toner was heated and dried at 40 ° C., but no binding or the like was generated, and the thin film-coated toner 1-1 was obtained by a simple crushing operation.
[0138]
The volume average particle diameter of the obtained thin film-coated toner 1-1 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0139]
Further, the image forming properties of the thin film-coated toner 1-1 were tested. The toners had sufficient transport properties, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0140]
(Example 1-2) Thin film-coated toner 1-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0141]
In 300 parts by mass of the dispersion liquid of the obtained primary particles of the polymerized toner, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of 25% by mass aqueous solution at 25 ° C. has a pH of 4.5 and a concentration of 5% by mass. Was added. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a melamine resin.
[0142]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0143]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0144]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0145]
Thereafter, the thin film-coated toner was heated and dried at 40 ° C., but no binding or the like was generated, and the thin film-coated toner 1-2 was obtained by a simple crushing operation.
[0146]
The volume average particle diameter of the obtained thin film-coated toner 1-2 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0147]
Further, the image forming properties of the thin film-coated toner 1-2 were tested. As a result, the toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0148]
(Preparation of concentrated urea resin precursor)
First, 1 mol part of urea and 2 mol parts of formaldehyde were condensed at 75 ° C. in the presence of ammonia to obtain a viscous syrup. This was evaporated under vacuum to adjust the resin component to 60% by mass to obtain a concentrated urea-based resin precursor.
[0149]
(Example 2-1) Thin film-coated toner 2-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0150]
In 300 parts by mass of the dispersion liquid of the primary particles of the obtained polymerized toner, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of 8,000 mPa · s at 25 ° C. has a pH of 3.6 and a concentration of 5% by mass. Was added. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a urea resin.
[0151]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0152]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0153]
Thereafter, the thin-film-coated toner was heated and dried at 40 ° C., but no binding or the like occurred, and a thin-film-coated toner 2-1 was obtained by a simple crushing operation.
[0154]
The volume average particle diameter of the obtained thin film-coated toner 2-1 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0155]
Further, the image forming properties of the thin film-coated toner 2-1 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0156]
(Example 2-2) Thin film-coated toner 2-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0157]
In 300 parts by mass of the dispersion liquid of the primary particles of the obtained polymerized toner, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of 8,000 mPa · s at 25 ° C. has a pH of 3.6 and a concentration of 5% by mass. Was added. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0158]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0159]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0160]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0161]
Thereafter, the thin film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and the thin film-coated toner 2-2 was obtained by a simple crushing operation.
[0162]
The volume average particle diameter of the obtained thin film-coated toner 2-2 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0163]
Further, the image forming property of the thin film-coated toner 2-2 was tested, and the toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0164]
(Example 3-1) Thin film-coated toner 3-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0165]
To 300 parts by mass of the dispersion of primary particles of the polymerized toner thus obtained, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added so that the concentration became 5% by mass, and urea 5 The parts by mass were mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, a resinification reaction was performed in 3 hours, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0166]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0167]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0168]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 3-1 was obtained by a simple crushing operation.
[0169]
When the volume average particle diameter of the obtained thin film-coated toner 3-1 was measured, it was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0170]
Further, the image forming property of the thin film-coated toner 3-1 was tested. The toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0171]
(Example 3-2) Thin film-coated toner 3-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.).
[0172]
To 300 parts by mass of the dispersion of primary particles of the polymerized toner thus obtained, polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added so that the concentration became 5% by mass, and urea 5 The parts by mass were mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour. The surface of the toner for the heat fixing method was coated with a urea resin.
[0173]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0174]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0175]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0176]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 3-2 was obtained by a simple crushing operation.
[0177]
The volume average particle diameter of the obtained thin film-coated toner 3-2 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0178]
Further, the image forming property of the thin film-coated toner 3-2 was tested. The toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0179]
(Example 4-1) Thin film-coated toner 4-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0180]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0181]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 4.5% by mass at 4.5. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the resulting mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a melamine resin.
[0182]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0183]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0184]
Thereafter, the thin-film-coated toner was heated and dried at 40 ° C., but no binding or the like was generated, and the thin-film-coated toner 4-1 was obtained by a simple crushing operation.
[0185]
When the volume average particle diameter of the obtained thin film-coated toner 4-1 was measured, it was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0186]
Further, the image forming properties of the thin film-coated toner 4-1 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0187]
(Example 4-2) Thin film-coated toner 4-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0188]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0189]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 4.5% by mass at 4.5. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the resulting mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a melamine resin.
[0190]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0191]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0192]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 4-2 was obtained by a simple crushing operation.
[0193]
When the volume average particle diameter of the obtained thin film-coated toner 4-2 was measured, it was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0194]
Further, the image forming properties of the thin film-coated toner 4-2 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0195]
(Example 4-3) Thin film-coated toner 4-3
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0196]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0197]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 4.5% by mass at 4.5. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a melamine resin.
[0198]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0199]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0200]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0201]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 4-3 was obtained by a simple crushing operation.
[0202]
The volume average particle diameter of the obtained thin film-coated toner 4-3 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0203]
Further, the image forming properties of the thin film-coated toner 4-3 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0204]
(Example 4-4) Thin film-coated toner 4-4
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0205]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0206]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 4.5% by mass at 4.5. Further, 8.2 mass of a hexamethylolmelamine prepolymer (trade name: Milbene 607, manufactured by Showa Polymer Co., Ltd.) was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a melamine resin.
[0207]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0208]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0209]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0210]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 4-4 was obtained by a simple crushing operation.
[0211]
The volume average particle diameter of the obtained thin film-coated toner 4-4 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0212]
Further, the image forming properties of the thin film-coated toner 4-4 were tested. As a result, the toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0213]
(Examples 4-5 to 4-8) Thin-film-coated toner 4-5 to 4-8
Except for adding 5 parts by mass of potassium chloride instead of alcohols when preparing the secondary particles of the polymerized toner, in the same manner as in the case of the thin-film coated toners 4-1 to 4-4, except that 5 parts by mass of potassium chloride is added. 4-8 were each produced. The resulting toner was tested for image forming properties. As a result, the toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0214]
(Preparation of concentrated urea resin precursor)
First, 1 mol part of urea and 2 mol parts of formaldehyde were condensed at 75 ° C. in the presence of ammonia to obtain a viscous syrup. This was evaporated under vacuum to adjust the resin component to 60% by mass to obtain a concentrated urea-based resin precursor.
[0215]
(Example 5-1) Thin film-coated toner 5-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0216]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0219]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 3.6% by mass at 3.6. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a urea resin.
[0218]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0219]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0220]
Thereafter, the thin-film-coated toner was heated and dried at 40 ° C., but no binding or the like occurred, and a thin-film-coated toner 5-1 was obtained by a simple crushing operation.
[0221]
The volume average particle diameter of the obtained thin film-coated toner 5-1 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0222]
Further, the image forming properties of the thin film-coated toner 5-1 were tested. As a result, the toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0223]
(Example 5-2) Thin film-coated toner 5-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0224]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0225]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 3.6% by mass at 3.6. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes, and a resinification reaction was performed in 3 hours. The surface of the toner for the heat fixing method was coated with a urea resin.
[0226]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0227]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0228]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 5-2 was obtained by a simple crushing operation.
[0229]
When the volume average particle diameter of the obtained thin film-coated toner 5-2 was measured, it was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0230]
Further, the image forming properties of the thin film-coated toner 5-2 were tested. As a result, the toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0231]
(Example 5-3) Thin film-coated toner 5-3
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0232]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0233]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 3.6% by mass at 3.6. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0234]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0235]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0236]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0237]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 5-3 was obtained by a simple crushing operation.
[0238]
The volume average particle diameter of the obtained thin film-coated toner 5-3 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0239]
The image forming properties of the thin film-coated toner 5-3 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0240]
(Example 5-4) Thin film-coated toner 5-4
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0241]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0242]
Thereafter, the added alcohols were removed, and polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the secondary particles of the polymerized toner to adjust the pH. It was added so that the concentration became 3.6% by mass at 3.6. Further, 1.5 parts by mass (dry) of the above concentrated urea-based resin precursor was mixed at room temperature. Thereafter, the obtained mixture at room temperature was heated to 55 ° C. in 20 minutes and a resinification reaction was performed in 1 hour, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0243]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0244]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0245]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0246]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 5-4 was obtained by a simple crushing operation.
[0247]
The volume average particle diameter of the obtained thin film-coated toner 5-4 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0248]
Further, the image forming properties of the thin film-coated toner 5-4 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0249]
(Examples 5-5 to 5-8) Thin-film coated toners 5-5 to 5-8
Except for adding 5 parts by mass of potassium chloride instead of alcohols when preparing the secondary particles of the polymerized toner, the same procedure as in the case of the thin-film coated toners 5-1 to 5-4 is carried out. 5-8 were each produced. The resulting toner was tested for image forming properties. As a result, the toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0250]
(Example 6-1) Thin film-coated toner 6-1
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0251]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0252]
Thereafter, the added alcohols were removed, and the concentration of polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the polymerized toner secondary particles. 5% by mass of urea was mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, a resinification reaction was performed in 3 hours, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0253]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0254]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0255]
Thereafter, the thin-film-coated toner was dried by heating at 40 ° C., but no binding or the like was generated, and the thin-film-coated toner 6-1 was obtained by a simple crushing operation.
[0256]
When the volume average particle diameter of the obtained thin film-coated toner 6-1 was measured, it was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0257]
Further, the image forming properties of the thin film-coated toner 6-1 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0258]
(Example 6-2) Thin film-coated toner 6-2
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0259]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0260]
Thereafter, the added alcohols were removed, and the concentration of polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the polymerized toner secondary particles. 5% by mass of urea was mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, a resinification reaction was performed in 3 hours, and the surface of the toner for the heat fixing method was coated with a urea resin.
[0261]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0262]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0263]
Thereafter, the thin-film-coated toner was heated and dried at 40 ° C., but no binding or the like occurred, and a thin-film-coated toner 6-2 was obtained by a simple crushing operation.
[0264]
The volume average particle diameter of the obtained thin film-coated toner 6-2 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0265]
Further, the image forming properties of the thin film-coated toner 6-2 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0266]
(Example 6-3) Thin film-coated toner 6-3
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0267]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol is added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol is further added while stirring, and the secondary particles of the polymerized toner (glass transition temperature: 45 ° C).
[0268]
Thereafter, the added alcohols were removed, and the concentration of polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the polymerized toner secondary particles. 5% by mass of urea was mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour. The surface of the toner for the heat fixing method was coated with a urea resin.
[0269]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0270]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0271]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0272]
Thereafter, the thin film-coated toner was heated and dried at 40 ° C., but no binding or the like was generated, and the thin film-coated toner 6-3 was obtained by a simple crushing operation.
[0273]
The volume average particle diameter of the obtained thin film-coated toner 6-3 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0274]
Further, the image forming property of the thin film-coated toner 6-3 was tested. The toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0275]
(Example 6-4) Thin film-coated toner 6-4
A quinacridone-based pigment and an aluminum di-tert-butylsalicylate compound were mixed with 100 parts by mass of a styrene monomer and 20 parts by mass of an n-butyl acrylate monomer, and dispersed for 5 hours. 2.3 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added and polymerized to prepare polymerized toner primary particles (glass transition temperature: 45 ° C.) having a volume average particle diameter of 0.7 μm.
[0276]
A mixture of 15 mL of butyl alcohol and 3 mL of pentyl alcohol was added to 100 mL of the dispersion liquid of the primary particles of the polymerized toner while stirring, and 30 mL of isopropyl alcohol was further added while stirring. Thereafter, the dispersion was heated to 80 ° C. to prepare polymerized toner secondary particles (glass transition temperature: 45 ° C.).
[0277]
Thereafter, the added alcohols were removed, and the concentration of polyacrylic acid having a solution viscosity of 8,000 mPa · s at 25 ° C. of a 25% by mass aqueous solution was added to 300 parts by mass of the obtained dispersion liquid of the polymerized toner secondary particles. 5% by mass of urea was mixed, and the pH was adjusted to 3.2 with an aqueous sodium hydroxide solution. Then, 12.5 parts by mass of formalin was mixed at room temperature, the temperature was raised to 60 ° C. in 20 minutes, and a resinification reaction was performed in 1 hour. The surface of the toner for the heat fixing method was coated with a urea resin.
[0278]
Subsequently, the temperature of the mixture was raised to 70 ° C. and maintained for 2 hours while stirring.
[0279]
Then, the mixture was cooled to room temperature, and the thin film-coated toner was precipitated by centrifugation at 4,000 rpm for 10 minutes, and the supernatant was removed to collect the thin film-coated toner. The sedimentation was good.
[0280]
The operation of suspending the collected thin film-coated toner again in water, centrifuging it and removing the supernatant was repeated four times, and the thin film-coated toner was washed to remove polyacrylic acid. Detergency was good.
[0281]
Thereafter, the thin-film-coated toner was heated and dried at 40 ° C., but no binding or the like was generated, and a thin-film-coated toner 6-4 was obtained by a simple crushing operation.
[0282]
The volume average particle diameter of the obtained thin film-coated toner 6-4 was 8 μm, and the average thickness of the thin film was 0.03 μm. In addition, it was confirmed from the fact that the included toner did not leak in the heating and shaping step of the toner, that the surface coating was continuous.
[0283]
The image forming properties of the thin film-coated toner 6-4 were tested. The toners had sufficient transportability, could be fixed at a sufficiently low temperature, and could form high-quality images. In addition, fixing at 100 ° C. was possible.
[0284]
(Examples 6-5 to 6-8) Thin-film coated toners 6-5 to 6-8
Except for adding 5 parts by mass of potassium chloride instead of alcohols when preparing the secondary particles of the polymerized toner, the same procedure as in the case of the thin-film coated toners 6-1 to 6-4 is carried out. 6-8 were each produced. The resulting toner was tested for image forming properties. As a result, the toner had sufficient transportability, could be fixed at a sufficiently low temperature, and could form a high-quality image. In addition, fixing at 100 ° C. was possible.
[0285]
【The invention's effect】
By coating the surface of the polymerized toner and the polymerized and aggregated toner with the thermosetting resin, both the low blocking property and the low temperature fixing of the polymerized toner and the polymerized and aggregated toner can be achieved.
[0286]
In particular, by coating the surface of the polymerized toner and the polymerized aggregated toner having a low softening temperature, sufficient antiblocking properties can be realized without significantly increasing the softening temperature, and both a low fixing temperature and a low locking property can be achieved.
[0287]
As described above, by using the surface-coated polymerized toner and the surface-coated polymerized toner having low softening temperature and rocking property, fixing at a sufficiently low fixing temperature is realized, heat energy required for fixing is reduced, and fixing time is reduced. , And energy saving and speeding up of the fixing process can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining a method of coating a thin film on the surface of primary particles of a polymerized toner with a thermosetting resin.
FIG. 2 is a schematic diagram for explaining a method of coating the surface of secondary particles of a polymerized toner with a thermosetting resin in a thin film.
[Explanation of symbols]
10 Primary toner particles
11 Primary toner particles
20 Toner secondary particles
30 Surface thin film
31 Surface thin film

Claims (9)

A toner in which primary particles of a polymerized toner are surface-coated with a thin film containing a thermosetting resin. A toner in which toner secondary particles mainly composed of aggregates of polymerized toner primary particles are surface-coated with a thin film containing a thermosetting resin. The toner according to claim 1, wherein the surface thin film is substantially continuous, and the toner before the formation of the surface thin film is a powder at normal temperature. 4. The toner according to claim 1, wherein the average thickness of the surface thin film is 0.005 to 1 [mu] m. The toner according to any one of claims 1 to 4, wherein the thermosetting resin is a urea resin or a melamine resin. A step of polymerizing a toner raw material containing a binder resin monomer, which is a raw material of the binder resin, to prepare a dispersion of toner primary particles;
Mixing a thermosetting resin precursor with the toner primary particle dispersion;
Forming the thermosetting resin precursor into a resin without melting the toner primary particles and coating the surface of the toner primary particles with a thin film containing the thermosetting resin. . A step of polymerizing a toner raw material containing a binder resin monomer, which is a raw material of the binder resin, to prepare a dispersion of toner primary particles;
Aggregating the toner primary particles to prepare a dispersion of toner secondary particles;
Mixing a thermosetting resin precursor with the dispersion of the toner secondary particles;
Forming the thermosetting resin precursor into a resin without melting the toner secondary particles, and coating the surface of the toner secondary particles with a thin film containing the thermosetting resin. . The method for producing a toner according to claim 7, wherein the secondary particles of the toner are heated after the secondary particles of the toner are prepared. 9. The method for producing a toner according to claim 6, wherein the toner whose surface is coated with the thin film is heated in a temperature range in which the thin film is not thermally broken.

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