JP2004029522A - Microencapsulated toner and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the copying speed of an electrophotographic apparatus up to the printing speed of a printing machine by achieving satisfactory fixation of a developer by short-time heating and pressing in the electrophotographic apparatus, and to improve cleanability. <P>SOLUTION: A microencapsulated toner in which a plurality of through holes exist in the capsule resin wall is used. The capsule resin wall is readily crushed by heating and pressing when a developer is fixed, and the contents including a coloring material are released and quickly fixed on a support. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a porous microcapsule toner, a method for producing a porous microcapsule toner, and uses of the porous microcapsule toner.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a method of copying a large amount of one document, printing has been generally performed because the document can be copied at a high speed, in a large amount, and at low cost. However, in recent years, demand for copying for personal use has increased, and copying of a certain number of copies is being performed using an electrophotographic apparatus such as a copying machine. This is because the electrophotographic apparatus does not require a plate or the like unlike a printing press, and is suitable for small-quantity and multi-type reproduction.
[0003]
In an electrophotographic apparatus, an image is formed by fixing a developer on a support such as paper. The developer is roughly classified into a two-component developer including a toner and another particle (carrier) that imparts a charge to the toner, and a single-component developer including a toner having a charge control ability. In these developers, the toner is a colored particle having a charging function, and is prepared using a binder, a coloring material, a charge control agent, a release agent, and the like. The types and blending amounts of these materials are carefully optimized, and developing characteristics such as charging properties, electrical resistance, magnetic properties and fluidity, fixing properties such as fixing properties and coloring properties, preservability, handling properties, etc. A good balance of performance required of the toner is realized.
[0004]
Microcapsule toners have been proposed for the purpose of comprehensively improving the required performance. The microcapsule toner is a fine capsule-shaped toner in which a core substance (also referred to as an inclusion) is coated with a thin film wall material (also referred to as a capsule wall). In addition, the capsule wall is separated into the handleability and the like, and the electrical resistance, magnetic property, fluidity, fixability and coloring property are separated into the inclusions, and these performances are highly controlled.
[0005]
As a method of fixing a microcapsule toner on a support to form an image, a pressure fixing method, a heat fixing method, and the like have been proposed. For example, a microcapsule toner for the pressure fixing method is disclosed in Japanese Patent Application Laid-Open No. Sho 59-65854. And JP-A-7-120963, JP-A-7-333886, and JP-A-8-30018.
[0006]
[Problems to be solved by the invention]
However, when duplicating an original with an electrophotographic device using a developer containing these microcapsule toners, the copying speed is sufficiently high for an electrophotographic system, but compared to a printing machine. In this case, since the duplication speed is low, it may take a long time to complete the duplication. In particular, in view of the duplicating ability of a printing press, if a large number of types of duplications are performed by a printing press in a small amount, the cost and time required for producing a plate or the like may be large. Therefore, an electrophotographic apparatus is considered to be suitable for small-quantity and multi-type copying, but since copying of an electrophotographic apparatus is slower than that of a printing machine, it may take a long time to complete the copying.
[0007]
One of the reasons why the copying of an electrophotographic apparatus is slower than that of a printing machine is that it takes time to fix the developer. The developer receives heat and pressure by a roller and a film and is fixed on a support such as paper. In order to sufficiently fix the developer, the developer needs to be heated and pressed for a predetermined time. . For this reason, it is necessary to pass the support to which the developer is attached through a nip formed by a roller and a film over a predetermined time, and there is a limit in shortening the fixing time. If the rotation of the roller and the sliding of the film are too fast, the time required for the support to pass through the nip may be too short, the pressure and heating of the developer may be insufficient, and the fixing of the developer may be insufficient. is there.
[0008]
Further, the toner remaining on the photoconductor after transferring the toner from the photoconductor to the support is cleaned with a cleaning blade and a cleaning brush. However, when a spherical toner such as a microcapsule toner is used, the remaining toner is cleaned. Cleaning may be incomplete due to the penetration of the blade and the cleaning brush. Furthermore, if the microcapsule toner has a distorted shape or a shape having a large number of protrusions in order to avoid such a problem, the adhesion of the microcapsule toner to the photoconductor may be insufficient.
[0009]
In view of such a situation, the present invention provides a microcapsule toner capable of sufficiently fixing a developer by short-time heating and pressurization, and reduces the copying speed of an electrophotographic apparatus to the printing speed of a printing machine. The purpose is to improve.
[0010]
Another object is to improve the cleaning property.
[0011]
[Means for Solving the Problems]
According to the present invention, there is provided a microcapsule toner in which a plurality of through holes are formed in a capsule resin wall.
[0012]
In the capsule resin wall of the conventional microcapsule toner, there is substantially no hole penetrating the capsule resin wall. On the other hand, the capsule resin wall of the microcapsule toner of the present invention has a plurality of holes penetrating the capsule resin wall. For this reason, the capsule resin wall is easily crushed by heating and pressurizing when fixing the developer, and the inclusions containing the coloring material are released and quickly fixed to the support. In addition, even when the capsule resin wall does not break, the inclusions are leaked through the through holes by heating and pressurization. As a result, the developer can be satisfactorily fixed by short-time heating and pressurization, so that the fixing time can be shortened.
[0013]
As a result, even when the support to which the developer is attached is passed in a short time through the nip formed by rollers and films, sufficient fixing of the developer can be realized, and the fixing time can be reduced. For example, the developer can be sufficiently fixed even when the rotation of the roller and the sliding of the film are performed at a high speed, or the size of the roller and the film is reduced to shorten the time of pressing and heating.
[0014]
Further, since the through-hole is formed in the capsule resin wall, the inclusion can be satisfactorily released without, for example, thinning or softening the capsule resin wall. Therefore, there is a high degree of freedom in designing the material, wall thickness, crosslink density and hardness of the capsule resin wall. As a result, the fixing time without impairing the performance required for the toner, such as developing characteristics such as chargeability, electric resistance, magnetic properties and fluidity, fixing characteristics such as fixing property and coloring property, storability and handleability. Can be shortened.
[0015]
As described above, when the microcapsule toner of the present invention is used, sufficient fixing of the developer can be realized by short-time heating and pressurization while sufficiently securing various performances required for the toner. Can be improved to the same level as the printing speed of a printing press.
[0016]
The electrophotographic apparatus is economical because it does not require a printing plate unlike a printing machine, can shorten the fixing time, and can reduce the size of the fixing apparatus.
[0017]
Further, when a large number of through holes are formed in the capsule resin wall of the microcapsule toner, when cleaning the residual toner on the photoconductor with a cleaning blade, a cleaning brush, or the like, the cleaning blade, the cleaning brush, and the microcapsule toner are used. , The remaining toner can be suppressed from penetrating the cleaning blade and the cleaning brush. Therefore, the cleaning performance can be improved while ensuring sufficient adhesion of the microcapsule toner to the photoconductor without forming the microcapsule toner in a distorted shape or a shape having many protrusions.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0019]
(Structure of microcapsule toner)
FIG. 1 schematically shows a microcapsule toner having a large number of through-holes in a capsule resin wall. In this case, the average particle diameter of the microcapsule toner is 10 μm, the average pore diameter of the pores is 0.1 μm, and the average density of the pores is 1 / μm ² . In order to actually measure these values, the values are measured using an electron micrograph of the porous microcapsule toner, and the measurement results are averaged.
[0020]
The average particle size of the microcapsule toner can be measured, for example, using a Coulter Multisider manufactured by Coulter Electronics (UK).
[0021]
The average pore diameter of the through-holes is preferably 0.001 μm or more, more preferably 0.01 μm or more, and still more preferably 0.05 μm or more, from the viewpoints of retention and release properties of the inclusions, capsule strength, and ease of production. On the other hand, 5 μm or less is preferable, 1 μm or less is more preferable, and 0.5 μm or less is further preferable.
[0022]
The average density of the through-holes is preferably 0.01 / μm ² or more, more preferably 0.1 / μm ² or more, from the viewpoints of retention and release properties of the inclusions, capsule strength, and ease of production. , more preferably 0.5 pieces / [mu] m ² or more, whereas, preferably 100 / [mu] m ² or less, more preferably 50 / [mu] m ² or less, more preferably 10 / [mu] m ² or less.
[0023]
The average particle size of the capsule is preferably from 5 to 15 μm from the viewpoints of retention and release properties of the inclusion, capsule strength, cleaning properties, ease of production, and the like.
[0024]
In addition, the strength of the microcapsules is set to a value that does not destroy the microcapsules during handling, and is within a predetermined range according to the use of the microcapsules.
[0025]
Since the strength of the microcapsules depends on the average wall thickness of the capsule resin wall, the average wall thickness of the capsule resin wall is also carefully set within a predetermined range. The average wall thickness of the capsule resin wall can be measured by fixing the microcapsule in an epoxy resin or the like, cutting the microcapsule, and observing the cross section with an electron microscope. The average wall thickness of the capsule resin wall measured in this way is preferably 0.0001 μm or more, more preferably 0.001 μm or more, and still more preferably 0.005 μm or more, while 5 μm or less, and more preferably 1 μm or less. Preferably, it is 0.5 μm or less.
[0026]
In addition, the retention and release properties of the microcapsule inclusions can be examined by tracking the state in which the inclusions of the microcapsules are eluted or released outside the microcapsules. Water-based substances such as water and aqueous solutions; IPA, ethyl acetate, methanol, ethanol, propanol, butanol, THF, benzene, toluene, xylene, chloroform, dichloromethane, hexane, MEK, acetone, acetonitrile; Organic substances such as DMSO, DMF, and pyridine can be used.
[0027]
The results of the dissolution test strongly depend on the inclusions in the microcapsules, the external substances of the dissolution test, the temperature and the time. In particular, depending on the properties of the external substance, by selecting an appropriate external substance, for example, it can be confirmed that a through hole exists in the capsule resin wall. That is, microcapsules of the same inclusion are produced under the condition that a through hole is formed in the capsule resin wall and under the condition that no through hole is formed. Then, the obtained microcapsules are immersed in an appropriate external substance such as THF, for example, and the behavior in which the inclusions elute at an appropriate temperature such as 40 ° C. is tracked. As a result, for example, by quantifying the inclusions released to the outside in a 30-minute dissolution test, the presence or absence of a through-hole can be confirmed. For example, in the case of a microcapsule in which a through-hole is formed, 95% by mass or more of the inclusion is released, whereas in the case of a microcapsule without a through-hole, the release amount is 5% by mass or less. .
[0028]
(Method for producing microcapsule toner)
Microcapsule toner can be manufactured by methods that mainly use chemical reactions, such as interfacial polymerization, in situ polymerization, in-liquid curing coating, and coacervation, but the structure of the resulting microcapsule toner is precisely controlled. For reasons such as possible, an interfacial polymerization method and an in situ polymerization method are preferred.
[0029]
In the interfacial polymerization method, the raw material for the capsule resin wall exists in both the internal medium of the microcapsule and the external medium of the microcapsule, and the raw material contained in the internal medium of the microcapsule and the raw material contained in the external medium of the microcapsule The raw material reacts to form a capsule resin wall.
[0030]
On the other hand, in the in situ polymerization method, the raw material for the capsule resin wall is present only in one of the internal medium of the microcapsule and the external medium of the microcapsule, and only the raw material contained in the internal medium of the microcapsule reacts. Thus, the capsule resin wall is formed, or only the raw material contained in the external medium of the microcapsule reacts to form the capsule resin wall.
[0031]
In the polymerization method as described above, the first liquid medium containing the first raw material of the capsule resin wall, the first surfactant strongly bonded to the first raw material, and the second surfactant weakly bonded to the first raw material At least. As described above, the raw material for the capsule resin wall is polymerized using two types of surfactants having different bonding strengths with the raw material for the capsule resin wall. In this case, it is considered that the capsule resin wall formed at the position where the surfactant having a weak bonding force with the raw material is present falls off the microcapsules after the completion of the polymerization. As a result, it is considered that a hole is formed at a position where the capsule resin wall has fallen, and a porous microcapsule is obtained.
[0032]
In such a mechanism, from the viewpoint of forming a good microcapsule toner, the strong bond between the surfactant and the raw material of the capsule resin wall is preferably a covalent bond, and the weak bond is a ionic bond and a bond due to intermolecular force. At least one of them is preferable. In this case, since the surfactant is covalently bonded to the obtained capsule resin wall, the degree of freedom of the properties of the capsule resin wall can be increased.
[0033]
In addition, from the same viewpoint, the amount of the first surfactant based on 100 parts by mass of the first raw material of the capsule resin wall is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 25 parts by mass or more, On the other hand, it is preferably at most 80 parts by mass, more preferably at most 60 parts by mass, even more preferably at most 45 parts by mass.
[0034]
Further, the amount of the second surfactant based on 100 parts by mass of the first raw material of the capsule resin wall is preferably 0.4 parts by mass or more, more preferably 1.0 part by mass or more, and still more preferably 1.5 parts by mass or more. On the other hand, the amount is preferably 15.4 parts by mass or less, more preferably 9.6 parts by mass or less, and even more preferably 5.8 parts by mass or less.
[0035]
In addition, as a ratio of the amount of the first surfactant to the amount of the second surfactant, the second surfactant is preferably at least 1 part by mass, and more preferably 3 parts by mass with respect to 100 parts by mass of the first surfactant. Or more, more preferably 6 or more parts by mass, on the other hand, 40 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 15 parts by mass or less.
[0036]
The amount of the first surfactant used is preferably 0.5% by mass or more, more preferably 1% by mass or more, and preferably 10% by mass or less, and more preferably 5% by mass, based on the entire amount of the encapsulation reaction. % Is more preferable. The amount of the second surfactant used is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, while 1% by mass or less is preferable, and 0.5% by mass or less is more preferable.
[0037]
On the other hand, at least a first liquid medium containing the first material of the capsule resin wall, a polymer surfactant having an affinity for the first material, and a monomer surfactant having an affinity for the first material are used. You can also. In this way, the raw material for the capsule resin wall is polymerized using two types of surfactants having different molecular weights. In this case, since the low molecular weight surfactant has a lower anchor effect than the high molecular weight surfactant, the capsule resin wall formed at the position where the low molecular weight surfactant is present becomes a microcapsule after the polymerization is completed. It is thought that it will fall off. As a result, it is considered that a hole is formed at a position where the capsule resin wall has fallen, and a porous microcapsule is obtained.
[0038]
In such a mechanism, from the viewpoint of forming a good microcapsule toner, the weight average molecular weight of the polymer surfactant is preferably 1,000 to 1,000,000, and the molecular weight of the monomer surfactant is 100 Preferably it is ~ 1,000.
[0039]
Further, it is preferable that the raw material of the capsule resin wall is covalently bonded to the polymer surfactant. In this case, since the surfactant is covalently bonded to the obtained capsule resin wall, the degree of freedom of the properties of the capsule resin wall can be increased.
[0040]
Further, the amount of the polymer surfactant with respect to 100 parts by mass of the first raw material of the capsule resin wall is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, still more preferably 25 parts by mass or more, while 80 parts by mass. Or less, more preferably 60 parts by mass or less, and even more preferably 45 parts by mass or less.
[0041]
In addition, the amount of the monomer surfactant based on 100 parts by mass of the first raw material of the capsule resin wall is preferably 0.4 parts by mass or more, more preferably 1.0 part by mass or more, and further preferably 1.5 parts by mass or more. On the other hand, it is preferably 15.4 parts by mass or less, more preferably 9.6 parts by mass or less, and still more preferably 5.8 parts by mass or less.
[0042]
Further, as a ratio of the amount of the polymer surfactant and the amount of the monomer surfactant, 100 parts by mass of the polymer surfactant, the monomer surfactant is preferably 1 part by mass or more, 3 parts by mass or more is more preferable, 6 parts by mass or more is more preferable, while 40 parts by mass or less is preferable, 25 parts by mass or less is more preferable, and 15 parts by mass or less is further preferable.
[0043]
In addition, with respect to the whole at the time of the encapsulation reaction, the amount of the polymer surfactant used is preferably 0.5% by mass or more, more preferably 1% by mass or more, while 10% by mass or less, and preferably 5% by mass or less. % Is more preferable. The amount of the monomer surfactant used is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, while 1% by mass or less is preferable, and 0.5% by mass or less is more preferable.
[0044]
In addition, if necessary, three or more surfactants can be used.
[0045]
The surfactant is not particularly limited, and any of an anionic monomer, a cationic monomer, a nonionic monomer, an anionic polymer, a cationic polymer, and a nonionic polymer can be used. Among them, anionic monomers, anionic polymers, etc. are preferred because of high emulsifying ability, high protection of the capsule inclusions, excellent cohesiveness of the capsule resin wall, and not hindering the capsule resin wall forming reaction. preferable.
[0046]
Specifically, alkylbenzene sulfonates such as sodium benzenesulfonate and sodium dodecylbenzenesulfonate, polyoxyethylene sulfate, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride Use is made of an acid copolymer, poly (meth) acrylic acid, polyvinyl alcohol, hexaethylcellulose, methylcellulose, carboxymethylcellulose, kaizen, gum arabic, gelatin, funnel oil and the like.
[0047]
For example, when forming a capsule resin wall from trimethylol melamine by an in situ polymerization method, a ring-opened product obtained by partially hydrolyzing maleic anhydride of a styrene-maleic anhydride copolymer as a first surfactant is preferable. As the second surfactant, sodium dodecylbenzenesulfonate or the like is preferable. When a maleic anhydride partially hydrolyzed ring-opened product of a styrene-maleic anhydride copolymer is used, the carboxyl group generated by the ring opening is oriented in an aqueous phase, aggregates trimethylolmelamine, and further forms an amide bond. The ring-opened product of the styrene-maleic anhydride copolymer obtained by partial hydrolysis of maleic anhydride has a high molecular weight, and thus has a sufficient anchor effect. On the other hand, sodium dodecylbenzenesulfonate aggregates trimethylolmelamine due to intermolecular force, but does not react and does not covalently bond. Further, since sodium dodecylbenzenesulfonate has a low molecular weight, it has a weak anchor effect and drops off after the completion of the polymerization reaction.
[0048]
From the above viewpoint, the ring opening ratio of maleic anhydride is preferably 30 to 80%.
[0049]
The carboxyl group formed by ring opening is more preferable because it accelerates the self-condensation reaction of trimethylolmelamine as an acidic catalyst.
[0050]
When high purity is required for the inclusions of the microcapsules, the first liquid medium is preferably the external medium of the microcapsules. In this case, the raw material exists only in the external medium of the microcapsule, and the raw material reacts to form a capsule resin wall. Therefore, no unreacted raw material remains inside the microcapsule, and there is no reaction by-product. .
[0051]
In the case where the interfacial polymerization method is employed, a second liquid medium containing a second raw material that reacts with the first raw material to form the capsule resin wall is further used. In this case, if the first liquid medium is the external medium of the microcapsule, the second liquid medium is the internal medium of the microcapsule.
[0052]
The capsule resin wall may be either thermosoftening or thermosetting, and is selected in consideration of the properties of the capsule inclusion, the desired microcapsule structure, and the like. Among them, urea resin, melamine resin, polyurethane resin, urethane-urea resin, polyamide resin, polyester resin, polyether resin, polyolefin resin, polysulfonamide resin, polysulfonate resin, etc. Epoxy resins, polycarbonate resins, phenol resins, and the like are preferable, and two or more resins can be used in combination as needed.
[0053]
Specifically, for example, when the capsule resin wall is made of a urea resin, an in situ polymerization method using a methylolated urea compound, an interfacial polymerization method using a urea compound and formaldehyde, a carbonyl halide compound and an amine It can be produced by an interfacial polymerization method using the same.
[0054]
When the capsule resin wall is made of a melamine resin, it can be produced by an in situ polymerization method using a methylolated melamine compound, an interfacial polymerization method using a melamine compound and formaldehyde, or the like.
[0055]
When the capsule resin wall is made of a polyurethane resin, an interfacial polymerization method using an isocyanate compound and a hydroxyl compound, an interfacial polymerization method using a carbonyl monooxy compound and an amine, and an amino-carbonyl monooxy compound are used. It can be produced by the used in situ polymerization method or the like.
[0056]
When the capsule resin wall is made of a urethane-urea resin, it can be manufactured by an interfacial polymerization method using an isocyanate compound and water, an interfacial polymerization method using an isocyanate compound and amines, or the like.
[0057]
When the capsule resin wall is made of a polyamide resin, it can be manufactured by an in situ polymerization method using an amino acid derivative, an interfacial polymerization method using a carboxylic acid derivative and an amine, or the like.
[0058]
When the capsule resin wall is made of a polyester resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0059]
When the capsule resin wall is made of a polyether resin, it can be made by an interfacial polymerization method using a carboxylic acid derivative and a hydroxyl compound.
[0060]
When the capsule resin wall is made of a polyolefin resin, the capsule resin wall is made by an in situ polymerization method using ethylene, propylene, styrene, (meth) acrylic acid, (meth) acrylate, vinyl acetate, styrene-divinylbenzene, or the like. it can.
[0061]
When the capsule resin wall is made of a polysulfonamide resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and an amine.
[0062]
When the capsule resin wall is made of a polysulfonate resin, it can be made by an interfacial polymerization method using a sulfonic acid derivative and a hydroxyl compound.
[0063]
When the capsule resin wall is made of an epoxy resin, it can be manufactured by an interfacial polymerization method using an epoxide and a hydroxyl compound, an interfacial polymerization method using an epoxide and an amine, or the like.
[0064]
When the capsule resin wall is made of a polycarbonate resin, it can be manufactured by an interfacial polymerization method using a hydroxy compound and a carbonyl halide compound.
[0065]
When the capsule resin wall is made of a phenol resin, it can be manufactured by an interfacial polymerization method using an aromatic hydroxy compound and formaldehyde, an interfacial polymerization method using a urea compound and an aromatic hydroxy compound, and the like.
[0066]
In addition, as raw materials of the capsule resin wall, in addition to the above, polyisocyanate, polyisothiocyanate, polyamine, polycarboxylic acid, polybasic acid chloride, acid anhydride, epoxy compound, polyol, (meth) acrylic compound, polysulfide, Organic amines, acid amides, water-soluble epoxy compounds, phenols, formalin, phosgene, spiroacetal heterocyclic amines, aldehydes and the like can also be used.
[0067]
Among the capsule resin walls described above, melamine resin, urea resin, epoxy resin, phenol resin, and the like are thermosetting resins. Further, a polyurethane resin, a urethane-urea resin, a polyamide resin, a polyester resin, a polyether resin, a polyolefin resin, a polysulfonamide resin, a polysulfonate resin, a polycarbonate resin and the like are thermosoftening resins. Of these resins, thermosetting resin has higher hardness than thermosoftening resin, so if the capsule resin wall is formed of thermosetting resin, even if a large number of through holes are formed in the capsule resin wall, The release property of the inclusions can be improved without significantly reducing the capsule strength. From such a viewpoint, among the thermosetting resins, for example, a melamine resin is preferable.
[0068]
In the encapsulation reaction described above, the reaction temperature is usually set to 50 to 100 ° C.
[0069]
(Inclusion of microcapsule toner)
The inclusions of the microcapsule toner are a binder, a coloring material, and the like, and an internal medium that is a dispersion medium of these. Further, if necessary, additives such as a charge control agent, a release agent, and a fixing property improving agent such as silicone oil can be added.
[0070]
The internal medium of the microcapsule toner is selected in consideration of the properties of the inclusions, the required performance of the microcapsule toner, the cleaning property, the application field of the microcapsule toner, and the like.From the viewpoint of producing a good microcapsule toner, for example, Plasticizers are preferred. Specifically, dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), di-n-octyl Phthalate esters such as phthalate, diisodecyl phthalate, butylbenzyl phthalate, diisononyl phthalate, ethyl phthalyl ethyl glycolate; trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate (TBP) Tri-2-ethylhexyl phosphate (TOP), tributoxyethyl phosphate, trioleyl phosphate, triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), Phosphates such as xylenyl diphenyl phosphate (XDP) and 2-ethylhexyl diphenyl phosphate; trimellitic esters such as tri-2-ethylhexyl trimellitate; benzoic esters such as butyl benzoate and hexyl benzoate; salicylic acid Salicylates such as isoamyl, benzyl salicylate, methyl salicylate, ethyl salicylate; dimethyl adipate (DMA), diisobutyl adipate (DIBA), Butyl adipate (DBA), di-2-ethylhexyl adipate (DOA), diisodecyl adipate, dibutyl diglycol adipate, dibutyl diglycol adipate, di-2-ethylhexyl acetate, dimethyl sebacate, dibutyl sebacate, di-2-ethylhexyl Fatty acid esters such as sebacate and methylacetyl ricinolate; aliphatic dicarboxylic acid esters such as dibutyl fumarate, diethyl malonate and dimethyl oxalate; citrate esters such as o-acetyltriethyl citrate; methylnaphthalene and dimethyl Alkyl naphthalenes such as naphthalene, monoisopropyl naphthalene and diisopropyl naphthalene; o-methyl diphenyl ether, m-methyl diphenyl ether, p-methyl diphenyl ether and the like Alkyl diphenyl ethers; amide compounds of higher fatty acids or aromatic sulfonic acids such as N, N-dimethyl lauryl amide and N-butyl benzene sulfonamide; trimellitic esters such as trioctyl trimellitate; dimethyl diphenyl methane and the like Diarylalkanes such as diarylethane such as diarylmethane, 1-phenyl-1-methylphenylethane, 1-dimethylphenyl-1-phenylethane, 1-ethylphenyl-1-phenylethane; chlorinated paraffins; acrylic acid esters Polymerizable compound, acrylamide polymerizable compound, methacrylic acid polymerizable compound, methacrylic acid ester polymerizable compound, methacrylamide polymerizable compound, maleic anhydride polymerizable compound, maleic ester polymerizable compound, polystyrene System polymerizable compound, vinyl ether-based polymer compounds, polyvinyl ester compounds, using a vinyl-polymerizable medium, such as allyl ether-based polymer compound.
[0071]
As the binder, a fixing resin or the like can be used. Specifically, poly (meth) acrylate, poly (ethyl) acrylate, poly (butyl) acrylate, poly (meth) acrylate 2 -(Meth) acrylic acid ester polymers such as ethylhexyl and poly (meth) lauryl acrylate; copolymers of styrene monomers and (meth) acrylic acid esters; polyvinyl acetate, vinyl polypropionate, polyvinyl butyrate, Ethylene polymers such as polyethylene and polypropylene and copolymers thereof; styrene copolymers such as styrene / butadiene copolymer, styrene / isoprene copolymer, styrene / maleic acid copolymer; polyvinyl ether, polyvinyl ketone; Polyester, polyamide, polyurethane, rubbers, epoxy resin, polyvinyl Butyral, rosin, modified rosin, terpene resin, phenol resin is used alone or in combination.
[0072]
In particular, when a polymer having a long-chain alkyl group such as lauryl methacrylate homopolymer or copolymer (for example, styrene / lauryl methacrylate copolymer) is used as the binder, aliphatic saturated hydrocarbon or aliphatic saturated hydrocarbon is used. An organic solvent (for example, an isopropylene-based solvent) as a main component is preferable.
[0073]
Coloring materials include inorganic pigments such as carbon black, red iron oxide, navy blue and titanium oxide; azo pigments such as fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, and para brown; phthalocyanines such as copper phthalocyanine and metal-free phthalocyanine Pigments; condensed polycyclic pigments such as flavanthrone yellow, dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. Further, disperse dyes, oil-soluble dyes and the like can also be used.
[0074]
When a magnetic toner is used, a simple substance of a metal such as magnetite, ferrite, cobalt, iron, nickel, or an alloy thereof can be used as the magnetic powder.
[0075]
In addition, ink can be used as an inclusion. The porous microcapsules containing the ink can be suitably used as a toner, and the ink is sufficiently released by a pressure fixing method and a heat fixing method, so that the ink is quickly fixed to the support.
[0076]
Examples of such inks include oil-based inks, glycol inks, sublimable inks, resin-based inks, linseed inks, wax inks, pigment inks, dye inks, metal powder inks, paste inks, solid inks, solvent inks, and the like. Can be used.
[0077]
The microcapsule toner of the present invention can be suitably used in any of the pressure fixing system and the heat fixing system, but is particularly suitable for the pressure fixing system because of its excellent release property and leakage property of the inclusions.
[0078]
【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 and the like are used.
[0079]
(Example 1) Microcapsule toner 1
15 parts by mass of a ring-opened styrene-maleic anhydride copolymer obtained by partial hydrolysis of maleic anhydride (weight average molecular weight: 350,000, ring-opening ratio of maleic anhydride: 70%), and sodium dodecylbenzenesulfonate 1 part by mass was dissolved in 284 parts by mass of water, and the temperature was kept at 90 ° C. To this, 200 parts by mass of a solution of a black ink (trade name: BFT DX-1 manufactured by Teikoku Ink Co., Ltd.) kept at 90 ° C. was mixed and emulsified for 3 minutes using a homomixer. Thereafter, the obtained emulsion was heated to 70 ° C, 65 parts by mass of a trimethylolmelamine prepolymer (trade name: Sumireze Resin 607, manufactured by Sumitomo Chemical Co., Ltd.) was mixed, and the mixture was stirred at 70 ° C for 2 hours using a propeller-type stirrer. The mixture was stirred to perform an encapsulation reaction, and thus a microcapsule toner 1 was obtained.
[0080]
Observation of the obtained microcapsule toner 1 with an electron microscope revealed that a large number of through holes were formed in the capsule resin wall. The average particle size of the capsules was 7 μm, the average pore size of the pores was 0.1 μm, the average number of pores per capsule was 294, and the average density of the pores was 2.0 / μm ² .
[0081]
The average wall thickness of the capsule resin wall was 0.2 μm, and the microcapsule toner 1 had a sufficient strength.
[0082]
Further, when a dissolution test was performed on THF, IPA, n-hexane and acetonitrile at 40 ° C. for 30 minutes, 99% by mass, 97% by mass, 1% by mass and 100% by mass of the black ink were eluted, respectively.
[0083]
If an image is formed by a pressure fixing method using such a microcapsule toner 1, a high-quality image can be produced at a high speed. In addition, good cleaning properties can be realized.
[0084]
(Comparative Example 1) Microcapsule toner 2
Microcapsule toner 2 was produced in the same manner as microcapsule toner 1 except that sodium dodecylbenzenesulfonate was not used.
[0085]
Observation of the obtained microcapsule toner 2 with an electron microscope revealed that no through-hole was formed in the capsule resin wall. When a dissolution test was performed on THF, IPA, n-hexane, and acetonitrile at 40 ° C. for 30 minutes, 1% by mass, 2% by mass, 1% by mass, and 100% by mass of the inclusions eluted, respectively.
[0086]
When an image is formed by the pressure fixing method using such a microcapsule toner 2, the fixing speed is low. Further, the cleaning property is insufficient.
[0087]
【The invention's effect】
By using microcapsule toner with multiple through-holes in the capsule resin wall, sufficient fixing of the developer can be achieved by short-time heating and pressurization, and the copying speed of the electrophotographic device can be reduced by printing on a printing press. Improve as fast as speed. Further, the cleaning property is improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining a porous microcapsule toner.

Claims (7)

A microcapsule toner having a plurality of through holes formed in a capsule resin wall. The average pore diameter of the through holes is 0.001 to 5 μm, the average density of the through holes per unit outer surface area of the capsule resin wall is 0.01 to 100 / μm ² , and the average particle diameter of the capsule. 2. The microcapsule toner according to claim 1, wherein the particle size is 5 to 15 μm. 3. The microcapsule toner according to claim 1, wherein the capsule resin wall is mainly made of a thermosetting resin. The microcapsule toner according to any one of claims 1 to 3, wherein the microcapsule toner contains an ink. A first liquid medium containing a first material of the capsule resin wall;
A first surfactant that strongly binds to the first raw material;
The method for producing a microcapsule toner according to any one of claims 1 to 4, further comprising a step of forming the capsule resin wall using at least the first raw material and a second surfactant weakly bound. The method according to claim 5, wherein the strong bond is a covalent bond, and the weak bond is at least one of an ionic bond and a bond by an intermolecular force. A first liquid medium containing a first material of the capsule resin wall;
A polymer surfactant having a weight average molecular weight of 1,000 to 1,000,000 having an affinity for the first raw material,
5. The method according to claim 1, further comprising a step of forming the capsule resin wall using at least the first raw material and a monomer surfactant having an affinity for a molecular weight of 100 to 1,000. The method for producing the microcapsule toner according to the above.

Images