JPH06295103A - Electrophotographic magnetic carrier and its production - Google Patents

Abstract

PURPOSE:To produce an electrophotographic magnetic carrier having excellent chargeability, with the core material grain and magnetic substance sufficiently dispersed, having a firm urethane-urea cross-linked structure, with the adhesion between the core material and coating material improved and capable of withstanding a long use by using a polymer obtained by polymerizing an ethylenic unsaturated monomer having only one fluoroalkyl group in one molecule for the coating material. CONSTITUTION:This electrophotographic carrier consists of a ferromagnetic fine grain and a resin. The resin is formed with a core material and a coating material, the core material is a polyurethane polyurea having a complex cross- linked structure having a urethane coupling and a urea coupling, and the coating material is a polymer obtained by polymerizing an ethylenic unsaturated monomer having >=2 fluoroalkyl group as the essential component.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a so-called two-component developer used for developing an electrostatic latent image or a magnetic latent image in the technical fields of electrophotography, electrostatic recording, electrostatic printing and the like. More specifically, the present invention relates to a magnetic substance dispersion type carrier comprising ferromagnetic fine particles and a resin, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In electrophotography, a photoconductive substance such as selenium, an organic semiconductor, or amorphous silicon is used as a photoconductor, an electrostatic latent image is formed by various means, and a magnetic brush is formed on the electrostatic latent image. A method in which toner is made to adhere by using a developing method or the like to make it visible is generally adopted.

In this developing process, a carrier is applied in order to impart a proper amount of positive or negative static electricity to the toner, form a magnetic brush on the developing sleeve containing a magnet, and convey the toner to the surface of the photoreceptor. The magnetic carrier particles referred to are used.

Conventionally, iron powder carriers have been used as carriers.
A ferrite carrier or a magnetic substance dispersion type carrier (a carrier in which magnetic substance fine particles are dispersed in a resin as described in JP-B-59-24416 and made into particles by means such as pulverization) is developed and put into practical use. Has been done.

Regarding iron powder carriers and ferrite carriers, the surface thereof is (meth) acrylic resin, vinyl chloride resin, fluorinated olefin resin, and fluorinated (meth) acrylate for the main purpose of controlling the triboelectric chargeability to toner. A so-called resin-coated carrier coated with a copolymer or the like is known, and for example, JP-A-51-117638.
JP, JP-A-53-97435, JP-A-57-
186759, JP-A-61-80162,
JP 61-120169 A, JP 61-120
170, JP 62-286062, JP 62-295074, and JP 62-80669.
JP-A-63-58361, JP-A-63-58361
No. 226663, JP-A-2-168273,
JP-A-2-168274, JP-A-2-2178
No. 69, Japanese Patent Laid-Open No. 2-280171, Japanese Patent Publication No. 2
-53782, etc.

However, since the conventional magnetic substance dispersion type carrier uses the thermoplastic styrene acrylic resin as described in Japanese Patent Publication No. 59-24416 as the binder, it is coated with an organic solvent. Since it is difficult to do so, resin-coated magnetic powder-dispersed carriers are not generally used.

[0007]

The problems of the conventional carriers are listed below. Iron powder carriers may have flake, sponge or spherical shapes, but the true specific gravity is 7 to 8 and the bulk specific gravity is 3 as well. 4, a large driving force is required to stir the developer, and a large impact force is applied to the toner and the photoconductor during the stirring, so that the toner is so-called spent, the chargeability of the carrier itself is deteriorated, and the photoconductor is deteriorated. It is easily damaged.

The shape of the ferrite carrier is spherical, the true specific gravity is 4.5 to 5.5, and the bulk specific gravity is 2 to 3, which considerably alleviates the problems of the iron powder carrier, but the recent high speed Copiers and high-speed laser printers tend to require high-speed stirring and high-speed development, and it is still insufficient to meet this demand.

The magnetic substance dispersion type carrier is, for example, Japanese Patent Publication No.
As described in Japanese Patent Application Laid-Open No. 9-24416, it is manufactured by melt-mixing magnetic fine powder and an insulating resin and then cooling and pulverizing. The bulk specific gravity is reduced from 1 to 2, but naturally. As a result, the shape becomes indefinite, the fluidity when the developer is stirred is poor, and it is still insufficient for high-speed development.
Further, this type of carrier has a drawback that when the amount of magnetic fine powder is increased in order to increase the magnetic force, hard magnetic fine particles are easily exposed on the surface of the carrier particles, which easily damages the photoreceptor.

As a means for solving the drawbacks of these conventional carriers, the present applicant has disclosed in Japanese Patent Application No. 3-250630 a composite cross-link containing a magnetic material mainly composed of urethane bonds and an outer shell mainly composed of urea bonds. We have proposed a new magnetic material-dispersed carrier consisting of structured particles.

However, the durability of the carrier and the difficulty of scratching the photoreceptor are still insufficient. In particular, the charging performance for positively chargeable toner is not always sufficient.

On the other hand, when the problems of the conventional fluororesin-coated carrier are listed, the fluororesin-coated resin for a carrier described in the above publication has poor adhesion to the carrier-core material, and thus is formed by being coated with these. Carrier
However, when repeated contact and collision with the toner and the photoconductor drum by a magnetic brush method or the like is caused, the coating layer is peeled or damaged, resulting in poor charging characteristics and poor durability.

Further, even if an attempt is made to use it together with another binder resin for the purpose of improving the adhesion to the core material, there is a problem that sufficient adhesion and durability cannot be obtained because of poor compatibility or affinity. It was

In addition to these problems, conventional fluorinated olefin resins often have no problem in terms of charge amount, but since they are extremely poor in solvent solubility, they are dry sprayed when applied to a carrier-core material. There is also a problem in production that a simple coating method such as a method cannot be applied, the coating work becomes complicated, and uniform coating is difficult.

In order to avoid such a problem, the above-mentioned fluorinated (meth) acrylate polymer has been proposed. In this case, if the charging property is adjusted to the required level, one molecule In addition, since a large amount of fluorinated (meth) acrylate component having one fluorinated alkyl group has to be used, there is a problem that solvent solubility decreases and coating workability deteriorates. There is also a problem in terms of physical properties and economy that the cost is increased, the abrasion resistance, the scratch resistance, the adhesion to the carrier-core material and the like are poor, and the coating properties are poor.

As described above, electrical properties such as chargeability are sufficiently exhibited with an appropriate fluorine content, and abrasion resistance, scratch resistance, and film mechanical characteristics such as adhesion to the carrier-core material. In addition, excellent carrier workability for the carrier-core material and excellent compatibility with the binder resin, excellent charging characteristics, charging stability, durability such as abrasion resistance and scratch resistance in the coated carrier, There is no fluororesin-coated carrier that exhibits environmental resistance, maintains the long life of the electrostatic image developer and maintains high recording image quality, and has excellent coating workability, carrier productivity, and economic efficiency. It was the current situation.

Some of the inventors of the present invention have previously been described in Japanese Patent Application No. 3-3.
In No. 12444, we proposed a new fluororesin-coated carrier, but the fact is that the adhesion between the core material and the coating resin is not always sufficient because iron powder or ferrite powder is used as the core. Met.

It is an object of the present invention to solve all the problems of the above conventional carrier and to provide a novel carrier and a method for producing the same which can cope with further high speed development.

More specifically, according to the present invention, the bulk specific gravity is small, the surface has a curved surface shape, the fluidity is good, and the developer can be stirred with a low driving force. It is an object of the present invention to provide a carrier and a manufacturing method thereof, which are less likely to be spent due to a small impact and can prolong the life of a developer. Furthermore, by producing with a manufacturing method in which the impact on the photoreceptor is small and the hard magnetic fine particles are hard to be exposed on the surface of the carrier particles, a high positive charge is imparted to the carrier that does not easily scratch the photoreceptor and to the toner. Carrier and a method for manufacturing the same.

[0020]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that Japanese Patent Application No. 3-25063.
Since the fluororesin-coated particles obtained by coating the core particles described in No. 0 with a fluororesin described in Japanese Patent Application No. 3-31244 have very good adhesion between the core material and the coating resin, electrophotography capable of solving the above-mentioned problems It has been found that the magnetic carrier has excellent performance as a magnetic carrier, and has reached the present invention.

That is, the first invention is an electrophotographic carrier composed of ferromagnetic fine particles and a resin, wherein the resin is composed of a core material and a coating material, and the core material is a composite crosslink composed of urethane bond and urea bond. A magnetic carrier for electrophotography, having a structure, wherein the coating material is a polymer obtained by polymerizing an ethylenically unsaturated monomer having two or more fluorinated alkyl groups as an essential component.

The second invention has ferromagnetic fine particles and one or more polar groups selected from the group consisting of sulfonic acid groups, sulfonic acid groups, carboxylic acid groups, and carboxylic acid groups. An ethylenic unsaturated having two or more fluorinated alkyl groups on the surface of a core material obtained by suspending and dispersing a mixture containing a polyol containing a polyol as a main component and a polyisocyanate in water containing a polyamine. A method for producing a magnetic carrier for electrophotography, which comprises coating a polymer obtained by polymerizing a monomer as an essential component.

Ferromagnetic materials used in the production of the core material particles of the present invention include gamma iron oxide, magnetite, and metals other than iron (Mn, Co, Ni, Zn, Mg, Cu, etc.).
One type or two or more types of spinel type ferrite, magnetoplumbite type such as barium ferrite, garnet type ferrites, chromium oxide, iron or alloy fine particles having an oxide film on the surface thereof can be used.

The shape of the ferromagnetic fine particles may be granular, spherical or acicular. By properly selecting the type and content of the ferromagnetic fine particle powder, carrier particles having a desired saturation magnetization can be obtained. For example, 4
Ferrites may be used to obtain a magnetization of 0 to 70 emu / g, and further 70 to 100 emu / g.
To obtain the magnetization of magnetite or Zn
It is sufficient to use spinel ferrite or the like containing Further, in order to obtain high magnetization of 100 emu / g or more, fine particles of iron or alloy having an oxide film on the surface may be used.

However, considering the chemical stability of the ferromagnetic fine particles, it is preferable to use the ferromagnetic fine particle powder of magnetite or ferrite. The content of the ferromagnetic fine particle powder is suitably 50 to 99% by weight, more preferably 60 to 95% by weight. When the amount is less than 50% by weight, the magnetic attraction force of the carrier particles is too weak, and a part of the carrier particles together with the toner depend on the type of the ferromagnetic material, the particle size of the carrier particles and the strength of the magnet in the sleeve. The phenomenon of sticking to the photoconductor, the so-called carrier pulling phenomenon, easily occurs.

When the content is more than 99% by weight, in other words, when the content of the binder resin is too small, the mechanical strength of the carrier particles becomes insufficient and the carrier particles become brittle and easily broken. As the polyol used in the production of the core material particles of the present invention, any polyol containing at least two active hydrogens and having a molecular weight of 62 to 100,000 can be used.

Specifically, for example, polyester polyol, polyether polyol, polyether ester polyol, polyester amide polyol, acrylic polyol, polyurethane polyol, polycarbonate polyol, epoxy polyol, epoxy modified polyol, polyhydroxyalkane, oil modified polyol,
Castor oil, silicone polyols or mixtures thereof may be mentioned.

Examples of polyester polyols include reaction products of polyhydric alcohols and polybasic acids. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexanediol, nonanediol, dodecanediol, methylpentanediol, trimethylpropanediol or dimethylisopropylpropanediol, hydroxystearyl alcohol, oleyl alcohol dimer, In addition to diols such as cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, ethylene oxide adduct of bisphenol A, and propylene oxide adduct of bisphenol A, Trimethylolpropane, glycerin, pentaerythritol Especially, sol, sorbitol, castor oil and the like are representative. Examples of polybasic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid, trimellitic acid. , And their anhydrides.

A polyester polyol obtained by ring-opening polymerization of a lactone such as caprolactone, methylcaprolactone, valerolactone or methylvalerolactone with glycol or the like can also be used.

Examples of polyether polyols include ethylene oxide, propylene oxide, butylene oxide, tetrohydrofuran, styrene oxide,
Epoxide compounds such as epichlorohydrin, phenyl glycidyl ether, and allyl glycidyl ether are polymerized in the presence of a catalyst, and these epoxide compounds can be added alone or in a mixture, or by alternately adding them to an active hydrogen-containing initiator. Examples of the active hydrogen-containing initiator include water, polyol, amino alcohol, polyamine and the like.

Examples of the polyether ester polyol include those obtained by subjecting the above-mentioned polyether as a raw material to a polyesterification reaction with the above-mentioned polyether, as well as a ring-opening copolymerization reaction of an epoxide compound and an acid anhydride. Compounds having both polyether and polyester segments in one molecule obtained by can be mentioned.

An example of the polyesteramide polyol is obtained by using a polyamine compound together in the above polyesterification reaction. A hydroxyl group-containing polymer generally referred to as an acrylic polyol can be synthesized by copolymerizing a monomer having one or more hydroxyl groups in one molecule with another monomer copolymerizable therewith. Examples of the monomer having a hydroxyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, trimethylolpropane acrylic acid monoester, methacrylic acid derivatives corresponding to these, polyhydroxyalkyl malate and fumarate. As the copolymerizable monomer, for example, acrylic acid, its methyl, ethyl, propyl, butyl, 2-ethylhexyl ester, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and their corresponding esters, further, Vinyl monomers such as styrene, α-methylstyrene, vinyl acetate, acrylonitrile, methacrylonitrile and the like can be mentioned.

As the polyurethane polyol, for example, a reaction product of the above-mentioned polyol and polyisocyanate having a hydroxyl group at the terminal can be mentioned. Further, a product obtained by reacting a part of the polyol by replacing it with the polyamine compound as described above can also be used as the polyurethane polyol.

An example of the epoxy polyol is a condensation type epoxy resin obtained by reacting a polyphenol compound or its hydrogenated product with epichlorohydrin,
Other than this, for example, an epoxy ester resin obtained by reacting a fatty acid with an epoxy resin, or a modified epoxy resin obtained by reacting with an alkanolamine can be used.

Examples of polyhydroxyalkanes include saponified products of vinyl acetate homopolymers or copolymers with other copolymerizable monomers having an ethylene bond, and polybutadiene polyols.

Further, not only the polyol compounds having a relatively high molecular weight described above, but also low molecular weight polyols having a molecular weight in the range of 62 to 400 can be used alone or in combination. These low molecular weight polyols include ethylene glycol, propylene glycol,
Butylene recall, neopentyl glycol, hexanediol, nonanediol, dodecanediol, methylpentanediol, trimethylpentanediol, hydroxystearyl alcohol, oleyl alcohol dimer, cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, poly In addition to diols such as oxypropylene glycol, polyoxybutylene glycol, hydrogenated bisphenol A, ethylene oxide adduct of bisphenol A, and propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol, sorbitol and the like can be mentioned. .

The polyol used in the production of the core material particles of the present invention is selected from the group consisting of a sulfonate group, a sulfonate group, a carboxylic acid group and a carboxylate group in the molecule of the above-mentioned polyol. A polyol whose main component is a polyol having one or more polar groups introduced is used, but it is preferable to use a polyol having this polar group and a polyol not having a polar group introduced in combination.

Examples of the method of introducing the sulfonic acid group and the sulfonic acid group include, for example, 2-sulfosodium-1,4-butanediol, 1-sulfosodium-
1,4-butanediol, 3-sulfosodium-
2,5-dimethyl-3-hexene-2,5-diol,
2,5-Disulfopotassium-3,4-hexanediol, 3-sulfopotassium-1,5-pentanediol, taurine, N, N-bis (2-hydroxyethyl)
Such as taurine or sulfobetaines, the monomers of _{various, HOROOCCH 2 CH (SO 3 M} ) COOR'OH [R, R ' is _{C n H 2n (n = 2~8} ), or is - (CH ₂ C
_{H 2 O) m - (CH} 2 CHCH 3 O) l - (m, l = 0~2
0), M is an alkali metal], and a sulfonic acid alkali metal base-containing glycol is used as a short-chain diol, or is used as an initiator of a new polyester polyol raw material glycol or polyether diol or polycaprolactone diol. It is possible to introduce a sulfonic acid group and a sulfonic acid group into the polyester polyol, polyether diol, and polycaprolactone diol.

As another introduction method, as an acid component of polyester polyol, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, 2-sodium sulfoisophthalic acid, 2-potassium sulfoisophthalic acid, sodium sulphate It is possible to introduce a sulfonate group and a sulfonate group into the polyester polyol by using phosuccinic acid or the like.

As a method for introducing a carboxylic acid group or a carboxylic acid group, for example, dimethylolpropionic acid or an alkali metal salt thereof is used as a short chain diol as it is, or a sulfonic acid group or a sulfonic acid group is introduced. In the same manner, it is possible to introduce a carboxylic acid group and a carboxylic acid group into polyester polyol, polyether diol, and polycaprolactone diol.

As described above, when a polar group (a sulfonic acid group, a sulfonic acid group, a carboxylic acid group, a carboxylic acid group) is introduced, the wetting of the ferromagnetic fine particles and the resin raw material is significantly improved, and the dispersion organic phase is dispersed. The effect of lowering the viscosity becomes remarkable. Therefore, there is an advantage that it is possible to reduce the necessary amount of the organic solvent used as described below.

Furthermore, what is noteworthy as the effect of introducing the polar group is the effect of firmly adhering the magnetic substance and the urethane urea resin to be formed to the same degree as or more than the effect of using the silane coupling agent. That is.

The total amount of sulfonate group, sulfonate group, carboxylic acid group, and carboxylate group introduced is preferably 0.001 to 1 mmol / g, more preferably 0.01 to 0.3 mmol / g, based on the total resin content. It is g. If the amount introduced is less than this range, the effect of decreasing the viscosity of the organic phase, reducing the amount of the organic solvent, and firmly adhering the urethane urea resin to the magnetic substance are lost. On the other hand, if the amount introduced is more than this range, the carrier becomes too hydrophilic, which adversely affects the charging property. In particular, in a high humidity environment, the amount of charge is reduced.

As the polyisocyanate used in the production of the core material particles of the present invention, any of those known per se can be used, but among them, only typical ones are exemplified. First, as aliphatic isocyanate, hexamethylene diisocyanate, 2,4-diisocyanate-1-methylcyclohexane, diisocyanate cyclobutane, tetramethylene diisocyanate, o-, m- or p-xylylene diisocyanate, hydrogenated xylylene is used as the aliphatic isocyanate. Diisocyanate, dicyclohexylmethane diisocyanate, dimethyldicyclohexylmethane diisocyanate, lysine diisocyanate, cyclohexane diisocyanate,
Dodecane diisocyanate, tetramethyl xylene diisocyanate, isophorone diisocyanate and the like. Further, only specific representative aromatic isocyanates are listed, for example, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate and 3-methyldiphenylmethane-4. 4,4'-diisocyanate,
m- or p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, naphthalene-
1,5-diisocyanate, diphenyl-4,4'-diisocyanate, 3,3'-dimethyldiphenyl-1,3,
Examples thereof include 5-triisopropylbenzene-2,4-diisocyanate carbodiimide-modified diphenylmetadiisocyanate, polyphenylpolymethylene isocyanate and diphenylether diisocyanate.

Other polyisocyanates include, for example, polyurethane polyisocyanates obtained by reacting an excess isocyanate compound with a polyhydroxy compound represented by various dihydric alcohols, trihydric alcohols or polyhydric alcohols having a valence of 4 or more. A method for obtaining, a method for obtaining a polyisocyanate containing an isocyanurate ring, or a method for obtaining a polyisocyanate containing an allophanate bond, which is obtained by polymerizing various diisocyanates or polyisocyanates as listed above, An isocyanate prepolymer obtained by a method of obtaining a polyisocyanate containing a buret bond reacted with water, a method of reacting with carbon dioxide, or the like may be used alone or in combination.

Here, in order that the obtained magnetic carrier is excellent in toughness, the number average molecular weight of the polyisocyanate is in the range of 200 to 10,000, preferably 300 to 7, Within the range of 000,
More preferably, the range of 500 to 5,000 is suitable.

In the present invention, it is preferable to use a silane coupling agent in order to disperse the ferromagnetic fine particles well in the resin. The silane coupling agent is an organosilicon monomer having two or more different reactive groups in the molecule, and one of the two reactive groups is a reactive group that chemically bonds with an inorganic substance (a methoxy group or an ethoxy group). , And the other reactive group is a reactive group (vinyl group, epoxy group, methacryl group, amino group, mercapto group, etc.) that chemically bonds to the organic synthetic resin.

Examples of commercially available silane coupling agents are vinyltrichlorosilane, vinyltris (βmethoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γmethacryloxypropyltrimethoxysilane, β- (. 3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β
(Aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-
Phenyl-γ-aminopropyltrimethoxysilane, γ
Examples thereof include mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane, which can be used in the present invention. The silane coupling agent more preferably used is one having an epoxy group, an amino group, or a mercapto group as a reactive group that chemically bonds to the organic synthetic resin, but is not limited thereto.

When the silane coupling agent is used, the wetting of the ferromagnetic fine particles with the resin raw material is improved, so that there is an effect that the magnetic material and the generated urethane urea resin are firmly adhered.

The silane coupling agent may be added directly to the organic phase of the present invention, or the surface of the ferromagnetic fine particles may be treated with the silane coupling agent in advance. The amount of the silane coupling agent used is 0.01 to 3% by weight of the ferromagnetic fine particles, more preferably 0.1 to 1% by weight.
Good to use.

If the amount of the silane coupling agent is less than 0.01% by weight, the effect of improving the wetting is not provided, and if it is more than 3% by weight, the effect of improving the wetting is not recognized and the cost is increased, which is not preferable.

In the present invention, a titanium coupling agent may be used instead of the silane coupling agent. Further, a silane coupling agent and a titanium coupling agent can be used in combination.

In the production of the core material particles of the present invention, aromatic or aliphatic hydrocarbons, esters are used as the organic solvent added and used in order to lower the viscosity of the organic phase and facilitate suspension particle formation. , Ethers, or ketones are suitable, and among them, benzene, toluene, xylene, cyclohexane, methylcyclohexane, diphenyl ether, mineral spirits and the like are suitable. The coupling agent may be previously dissolved in these solvents and added to the ferromagnetic fine particles.

Since it is necessary to remove the organic solvent after the completion of the urethane reaction and the urea reaction, it is preferable to use as little amount as possible. Examples of the polyamines that are preferably used by being added to water in the production of the core material particles of the present invention include known and commonly used diamines, polyamines, or a mixture thereof, but among them, particularly typical ones 1,2-ethylenediamine, bis (3-aminopropyl) amine, hydrazine,
Hydrazine-2-ethanol, bis (2-methylaminoethyl) methylamine, 1,4-diaminocyclohexane, 3-amino-1-methylaminopropane, N-hydroxyethylethylenediamine, N-methyl-bis (3
-Aminopropyl) amine, tetraethylenediamine,
Hexamethylenediamine, bis (N, N'-aminoethyl) -1,2-ethylenediamine, 1-aminoethyl-
1,2-ethylenediamine, diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine,
Aliphatic amines such as isophoronediamine, xylylenediamine, hydrogenated xylylenediamine, hydrogenated 4,4′-diaminodiphenylmethane, phenylenediamine, toluylenediamine, 2,4,6-triaminotoluene, 1,
There are aromatic amines such as 3,6-triaminonaphthalene and 4,4′-diaminodiphenylmethane. Further, there are various derivatives of the above-mentioned polyamines such as an epoxy compound, an adduct with an acrylic compound, and an amidation condensate with an organic carboxylic acid.

As the diamine compound having a sulfonate group, there are diaminotoluenesulfonic acid metal salt, naphthylenediamine sulfonic acid metal salt and the like, and these compounds may be used.

With respect to the amount of polyamine, 0.1 to 1.0 equivalent of polyamine, more preferably 0.3 to 0, is equivalent to 1 equivalent of excess isocyanate groups to OH groups of the polyol contained in the organic phase. It is better to add 8 equivalents.

A urea reaction is carried out at the core material particle interface,
Further, the core material particles of the present invention can be obtained by carrying out the urethanization reaction inside the particles. When suspending and dispersing the organic phase in the aqueous phase in the production of the core material particles, in order to stabilize the suspension dispersion, polyvinyl alcohol,
It is suitable to use one or more of various suspension stabilizers such as hydroxyalkyl cellulose, carboxyalkyl cellulose, gum arabic, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone or ethylene maleic anhydride copolymer. is there. The amount thereof is within a range of 0.01 to 20% by weight in the aqueous phase, and preferably,
It is preferable to use it within the range of 0.02 to 20% by weight. In the case of polyvinyl alcohol, the saponification degree is preferably 70 to 90 mol%. In addition, the aqueous phase may contain 0.001 to 1% by weight, preferably 0.002 to 1% by weight, of various known and conventional nonionic, anionic or cationic surfactants. All in all.

In producing the core material particles of the present invention,
The urethanization reaction is carried out inside the particles, but as is well known, the urethanization reaction between a hydroxyl group and an isocyanate group is a urea reaction with an amino group, particularly when the isocyanate group is based on an aliphatic system. The reaction rate tends to be smaller than that of the chemical reaction. As is well known, the reactivity between water and an isocyanate group is extremely small compared to the reactivity with a hydroxyl group, and the permeation effect of the outer wall formed by the addition of polyamines allows the permeation of water into the inside of particles. The object of the present invention, of course, is to carry out the urethanization reaction in the particles by raising the reaction temperature and taking time from a negligible place. For the purpose of accelerating the reaction with extremely effectively, dibutyltin oxide, cobalt naphthenate, zinc naphthenate,
Stannous chloride, stannic chloride, tetra-n-butyltin, tri-n-butyltin acetate, n-butyltin trichloride, trimethyltin hydroxide, dimethyltin dichloride, dibutyltin acetate, dibutyltin dilaurate, octene Such as tin acid or potassium oleate,
One or more kinds of various organometallic catalysts are added to the organic phase in an amount of 5 to 10,000 ppm, preferably 10 to 5.0.
It is desirable to add it in the range of 00 ppm, and by adding the organometallic catalyst, a tough magnetic carrier can be formed in an extremely short time.

That is, these organometallic catalysts can very effectively promote the reaction between the isocyanate group and the hydroxyl group. As the addition timing of the catalyst, prior to the dispersion in water, a step of adding in advance in the organic phase, or a step of dispersing the organic phase in water,
It is suitable to be performed in the middle of the step of adding the polyamines. The addition of the catalyst after adding the polyamines makes it difficult for the catalyst to be taken into the inside of the particle due to the state where the outer wall of the particle is being formed, and as a result, the urethanization reaction accelerating property inside the particle tends to decrease. It is not preferable because

In the production of the core material particles of the present invention, the resin raw materials constituting the organic phase, the compounding ratio, and the introduced amount of the polar group (sulfonic acid group, sulfonic acid group, carboxylic acid group, carboxylate group) in the resin The amount of the solvent added, the kind of the suspension stabilizer and / or the surfactant in the dispersion step and the amount thereof used, or various conditions such as the stirring speed and the reaction temperature in the dispersion step can be appropriately selected. The particle size can be freely designed and adjusted.

The average particle size of the core material particles of the present invention is designed according to the particle size of the toner used, the developing gap (distance between the photosensitive member and the developing sleeve) and the required resolution, but it is usually 10 to 300. It is in the range of micron (μm), and more preferably in the range of 15 to 150 μm.

For the particle size, a 50% volume average particle size can be measured using a laser diffraction particle size analyzer PRO-7000S manufactured by Seishin Enterprise Co., Ltd. The core material particles of the present invention are manufactured as follows. In the step (A) of adjusting the organic phase, first, the ferromagnetic fine particles, the polyol and a small amount of the organic solvent are mixed. At this time, if necessary, a kneading / dispersing device such as a kneader, an attritor, a ball mill, a sand mill, a roll mill or an ultrasonic homogenizer may be used. Next, polyisocyanate is added and mixed quickly to obtain an organic phase. An organometallic catalyst may be added at this stage. If necessary, various additives that are active or inactive with respect to the isocyanate group,
Charge control agents, carbon black, lubricants, and various synthetic resins such as xylene resin and ketone resin,
You may add and use it for an organic phase suitably. The step (B) of suspending and dispersing the above organic phase in an aqueous phase can be performed by a homomixer, a homodisper, an ultrasonic homogenizer, or the like. In many cases, it is more preferable to stir the dispersion system mildly by using a propeller stirrer or the like after the above-mentioned dispersion step is completed in order to make the particles spherical. Before the addition of the polyamines, the above-mentioned organometallic catalyst for urethanization reaction, such as dibutyltin dilaurate, is added to the suspension dispersion in a mildly stirred state. The polyamines are added to the dispersion, and the polyamines are preferably diluted with water or an organic solvent and added so that the active ingredient is 5 to 70%. Then, after several tens of minutes to several hours, the reaction temperature is raised to 40 to 95 ° C., preferably 50 to 90 ° C., and the temperature is maintained for 1 hour to several hours to terminate the reaction. .

The organic solvent added at the same time when the organic phase is prepared or when the polyamine is added is distilled off at the same time during the above reaction time, but if it still remains, it is completely removed under reduced pressure after completion of the reaction. Distill off. (C) When an alkali metal sulfonate or an alkali metal carboxylic acid is present on the surface of the core particle, 50% or more, preferably 90% or more of the alkali metal cation is a hydrogen ion, a divalent or higher valent metal cation, Alternatively, it is ion-exchanged with one or more cations selected from organic cations.

In this step, the column for the ion exchange resin is filled with the carrier of the present invention, and the ion exchange can be easily carried out by the same method as the ion exchange resin. Examples of divalent or higher valent metal cations are Mg, Ca, Ba, Z.
Metal ions such as n, Al, Sn, Fe, Co, Ni, Mn, and Cu may be used, and examples of the organic cation include ammonium salts such as trimethylbenzylammonium. (D) The polyurethane polyurea crosslinked particles containing the ferromagnetic fine particles thus obtained are thoroughly washed with water and dehydrated, and then the resin coating operation of the next step is performed.

In this specification, a production method in which water is used as a main component as a suspension / dispersion medium is disclosed, but a general organic solvent or a mixed solvent of an organic solvent and water is suspended. It can also be used as a dispersion medium.

Next, the coating polymer used for coating the surface of the core particle of the present invention will be described in detail. The inventors of the present invention have good adhesion to the core particles of the present invention, good solubility in organic solvents, and even a moderate fluorine content, in other words, a relatively small fluorine content. As a result of intensive investigations for a fluorine-based resin having a high positive charge-imparting ability for toner, it was found that an ethylenically unsaturated monomer having one fluorinated alkyl group in one molecule was polymerized as an essential component. It was found that these problems can be solved by using a polymer obtained by polymerizing an ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule as an essential component in place of the polymer of
The present invention has been completed.

In the present invention, it is necessary to contain an ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule as an essential component constituting the polymer used for coating the core material. This ethylenically unsaturated monomer is
It is extremely important in terms of coating workability on core materials, because it exhibits sufficient coating characteristics such as abrasion resistance, scratch resistance, adhesion to core materials, and an appropriate amount of fluorine from an economical point of view. In addition, it is extremely important in achieving the electrical / mechanical durability and environment resistance of the coated carrier.

In the present invention, the core material itself has a highly cross-linked structure composed of urethane bonds and urea bonds as described above, and the coating properties such as the adhesion of the polymer used for coating the core material to the core material and the like. , It is extremely important for the workability of coating the core material.

Examples of the ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule are as follows. General formula

[0070]

[Chemical 1]

[Here, Rf is a fluorinated alkyl group having 1 to 20 carbon atoms, and X and Y are 1 or 2. ]

[0072]

[Chemical 2]

[Here, Rf is the same as above, and Rf
f ′ is a fluorinated alkyl group having 1 to 20 carbon atoms, and Z
And Z 'is _{- (CH 2) X -,} - CH 2 CH (OH) (C
_{H 2) X -, - (} CH 2) X N (R1) SO 2 -, - (C
_{H 2) X N (R1)} CO- ( where X is as defined above, R1 is H or an alkyl group having 1 to 6 carbon atoms),
_{-CH (CH 3) -, -} CH (C 2 H 5) -, - C (C
_{H 3) 2 -, - CH} (CF 3) - or - (CF _{3) 2} - a divalent linking group such as, R and R 'is H or F. ]

[0074]

[Chemical 3]

[0075] [wherein, Rf, Rf ', Z, Z' are as defined above, R2 is _{H, Cl, CH 3, F} , or - (C
H ₂ ) _X Rf (where X and Rf are the same as above). ] The ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule further has two monovalent groups containing a fluorinated alkyl group, all of which are bonded to the same carbon atom. One of the monovalent groups having a skeleton and containing a fluorinated alkyl group has a polar atomic group between the carbon atom and the fluorinated alkyl group. To show

[0076]

[Chemical 4]

The skeleton having at least two monovalent groups containing a fluorinated alkyl group, all of which are bonded to the same carbon atom or nitrogen atom, is represented by (1). It is a skeleton. Three monovalent groups bonded to carbon atoms of the skeleton shown in (1) (in the above figure,

[0078]

[Chemical 5]

Among the ethylenically unsaturated monomers according to the present invention, in the monomer represented by the above general formula (A-4), at least one group having a polar atomic group does not exist. However, it is preferable that the skeleton of (1) has 2 to 6 polar atomic groups from the viewpoints of the charging characteristics, charging stability, durability, workability for coating the core material, and economical efficiency. In particular, 1 having 2 to 6 polar atomic groups in the skeleton of (1) and containing a fluorinated alkyl group
It is preferable that the valent group has 1 to 2 polar atomic groups.

[0080]

[Chemical 6]

The polar atomic group may be directly bonded to the fluorinated alkyl group, or indirectly bonded via another divalent linking group. The type of polar atomic group is not particularly limited, and examples thereof include an ester bond (-COO-) and urethane (-NHCOO-). In order to exhibit particularly high charging characteristics, charging stability, durability, and adhesion stability to the core material, it is preferable to select a urethane bond as the polar atomic group.

The portion excluding the skeleton (1) in the above figure is a group having a polymerizable α, β-ethylenically unsaturated double bond. The structure of this group is not particularly limited as long as it has polymerizability, but when the skeletons of (1) are exactly the same, α, β-ethylenically unsaturated double Those having a urethane bond or an ester bond in the groups having a bond tend to further improve the charging characteristics, charging stability, durability, adhesion stability to the core material, etc. of the obtained polymer.

The ethylenically unsaturated monomer (A
-4) is, for example, a general formula

[0084]

[Chemical 7]

[0085] In the formula, Rf, Z, R2 is the same as defined above, A is _{R3C (CH 2 -) 3 (} . However, R3 is H, a methyl group, an ethyl group, or a nitro group), or N (CH
_{2 CH 2) 3 -, N} (CH 2 CH (CH 3)) 3 - is a trivalent linking group represented by, B is -OCONHY1NHCO
O- (provided that Y1 is a divalent linking group having 15 or less carbon atoms and having a weight ratio in D of 35 to 65%). , Z1 is-(C
H _{2) m} -. (Where, m is an integer from 2 to 6) or -C
H ₂ CH (CH ₃₎ - is. ] It is a compound represented by.

In the general formula (A-5), two contained Zs may be different kinds of connecting groups selected from the group of the divalent connecting groups. A typical example of the Y1 group in the divalent linking group B is

[0087]

[Chemical 8]

And the like. Also the general formula

[0089]

[Chemical 9]

[Wherein Rf, Rf ', Z, Z', Z1,
R is as defined above, X1, X2, and X3 are -O.
COCH ₂ CH (R4) COO- (although, R4 is H, or an alkyl or alkenyl group having a carbon number of 1 to 36.), Or

[0091]

[Chemical 10]

[0092] a divalent connecting group selected from the group consisting of, A1 is _{R5C (CH 2 OCH 2 CH (} OH) CH 2)
_{3 -, R5C (CH 2 OCH} 2 CH 2 OCH 2 CH (OH) C
H _{2) 3} -. (However, R5 is H, hydroxymethyl group, a methyl group, an ethyl group, or a nitro group), N (CH _{2
CH 2 OCH 2 CH (OH)} CH 2) 3 -, or N (CH _{2
CH (CH 3) OCH 2 CH} (OH) CH 2) 3 - is a trivalent linking group represented by. ), A compound represented by the general formula

[0093]

[Chemical 11]

[Wherein Rf, Rf, Z, Z ', and R
Is the same as above, and X4 and X5 are -COO-, -OCO.
CH ₂ CH (R4) COO- (where, R4 is as defined above.)

[0095]

[Chemical 12]

Or a divalent linking group represented by -OCONHY1NHCOO- (where Y1 is the same as above). And a divalent linking group selected from ], A compound represented by the general formula

[0097]

[Chemical 13]

[Wherein Rf, Rf ', Z, Z1 and R are the same as defined above, and Rf "is Rf or Rf'.
And Z'may be the same or different, Z ″ is the same as Z or Z ′, and these may be the same or different, and X6, X7 , X8
May be the same or different and may be -O- or -OCON.
HY1NHCOO- (where Y1 is the same as above)
Is a divalent linking group represented by and X9 is -OCONH
Y1NHCOO- (where, Y1 is as defined above.) Or -OCONH (CH _{2) a} - (provided that, a represents an integer of 0 to 2.) A divalent linking group represented by, Z1 is the same as above. ] It is a compound represented by.

Specific examples of the ethylenically unsaturated monomer include the followings, but it goes without saying that the present invention is not limited to these specific examples.

[0100]

[Chemical 14]

[0101]

[Chemical 15]

[0102]

[Chemical 16]

[0103]

[Chemical 17]

[0104]

[Chemical 18]

[0105]

[Chemical 19]

[0106]

[Chemical 20]

[0107]

[Chemical 21]

[0108]

[Chemical formula 22]

[0109]

[Chemical formula 23]

[0110]

[Chemical formula 24]

[0111]

[Chemical 25]

[0112]

[Chemical formula 26]

[0113]

[Chemical 27]

The polymer according to the present invention may be a homopolymer of the above-mentioned fluorine-containing ethylenically unsaturated monomer, and may have desired charge amount, abrasion resistance, scratch resistance, adhesion to core material, etc. From the standpoint of obtaining coating properties, other conventionally known fluorine-based monomers, for example, fluorinated alkyl group-containing (meth) acrylate compounds and / or non-fluorine-based α, β-ethylenically unsaturated monomers are used. It may be a copolymer.

Examples of the fluorinated alkyl group-containing (meth) acrylate compound are as follows. _{CH 2 = CHCOOCH 2 CF 3 CH} 2 = CHCOOCH 2 CF 2 CF 3 CH 2 = CHCOOCH 2 CFHCF 3 CH 2 = C (CH 3) COOCH 2 CFHCF 3 CH 2 = CHCOOCH 2 CH 2 CF 3 CH 2 = CHCOOCH 2 CF _{2 CFHCF 3 CH 2 = CHCOOCH 2} CF (CF 3) CF 3 CH 2 = CHCOOCH (CF 3) 2 CH 2 = C (F) COOCH (CF 3) 2 CH 2 = C (CH 3) COOCH (CF 3) _{2 CH 2 = CHCOOCH 2 (CF} 2 CF 2) 2 H CH 2 = C (F) COOCH 2 (CF 2 CF 2) 2 H CH 2 = C (CH 3) COOCH 2 (CF 2 CF 2) 2 H CH _{2 = CHCOOCH 2 CF 2 CF 2} CFHCF 3 CH 2 = CHCOOCH 2 CF 2 CF 2 H CH 2 = C (CH 3) COOCH 2 CF 2 CF 2 H CH 2 = C (F) COOCH 2 _{CFCF 2 H CH 2 = CHCOOCH 2} CH 2 C 8 F 17 CH 2 = C (CH 3) COOCH 2 CH 2 C 8 F 17 CH 2 = CHCOOCH 2 CH 2 C 12 F 25 CH 2 = C (CH 3) COOCH _{2 CH 2 C 12 F 25 CH} 2 = CHCOOCH 2 CH 2 C 10 F 21 CH 2 = C (CH 3) COOCH 2 CH 2 C 10 F 21 CH 2 = CHCOOCH 2 CH 2 C 6 F 13 CH 2 = C ( _{CH 3) COOCH 2 CH 2 C} 6 F 13 CH 2 = CHCOOCH 2 CH 2 C 4 F 9 CH 2 = C (F) COOCH 2 CH 2 C 6 F 13 CH 2 = CHCOOCH 2 (CH 2) 6 CF (CF _{3) 2 CH 2 = CHCOOCH 2} (CF 2) 6 H CH 2 = CHCOOCH 2 (CF 2) 8 H CH 2 = C (CH 3) COOCH 2 (CF 2) 8 H CH 2 = CHCOOCH 2 (CF 2) ₁₀ H CH ₂ = CHCOOCH ₂ (CF ₂ ) _{1 2} H CH ₂ = CHCOOCH ₂ C (OH) HCH ₂ C ₈ F ₁₇ CH ₂ = CHCOOCH ₂ CH ₂ N (C ₃ H ₇ ) SO ₂ C ₈ F ₁₇ CH ₂ = CHCOOCH ₂ CH ₂ N (C ₂ H ₅ ) COOC ₇ F
₁₅ CH ₂ = CHCOO (CH ₂ ) ₂ (CF ₂ ) ₈ CF (CF ₃ ) ₂ Needless to say, the present invention is not limited to these exemplified compounds.

On the other hand, examples of the non-fluorine-based α, β-ethylenically unsaturated monomer include, for example, styrene, nucleus-substituted styrene, acrylonitrile, vinyl chloride, vinylidene chloride,
Fatty acid vinyl such as vinyl pyridine, N-vinyl pyrrolidone, vinyl sulfonic acid, vinyl acetate, etc., and α, β-ethylenically unsaturated carboxylic acid, that is, monovalent of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc. Or a divalent carboxylic acid or a derivative of an α, β-ethylenically unsaturated carboxylic acid having an alkyl group having 1 to 1 carbon atoms.
(Meth) acrylic acid alkyl ester (hereinafter, this expression generically refers to both acrylic acid alkyl ester and methacrylic acid alkyl ester), that is, methyl (ethyl), propyl, butyl of (meth) acrylic acid, Octyl, 2-ethylhexyl, decyl, dodecyl, stearyl ester, etc., and hydroxyalkyl ester of (meth) acrylic acid having 1 to 18 carbon atoms, that is, 2
-Hydroxyethyl ester, hydroxypropyl ester, hydroxybutyl ester, etc., and C1-18 aminoalkyl ester of (meth) acrylic acid, that is, dimethylaminoethyl ester, diethylaminoethyl ester, diethylaminopropyl ester, etc., also (meth) Acrylic acid C3-18 ether oxygen-containing alkyl ester, such as methoxyethyl ester, ethoxyethyl ester, methoxypropyl ester, methylcarbyl ester, ethylcarbyl ester, butylcarbyl ester, etc. 18 alkyl vinyl ethers such as methyl vinyl ether, propyl vinyl ether, dodecyl vinyl ether, etc., glycidyl esters of (meth) acrylic acid, ie glycidyl meth Acrylate, glycidyl acrylate, addition Sartomer styrene macromonomer 4500, Shin-Nakamura Chemical Co., Yu NK ester M-230G
Macromonomers such as γ-methacryloxypropylmethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropylmethyltrimethoxysilane, γ-acryloxypropylmethyldimethoxy. Examples thereof include silane-containing monomers such as silane and vinyltrimethoxysilane.

In the present invention, (meth) acrylic acid is a generic term for both methacrylic acid compounds and acrylic acid compounds, and (meth) acrylate is both a methacrylic acid compound and an acrylate compound. Shall be collectively referred to.

According to the knowledge of the present inventors, for the purpose of further improving the adhesiveness to the core material and the charging characteristics and improving the durability as a carrier, the copolymer monomer in the polymer according to the present invention is used. As −, a monomer containing a polar group, particularly a monomer containing an anionic group or a hydroxyl group in the molecule is preferable.

Specific examples of these monomers include acrylic acid, methacrylic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, partially sulfonated styrene, and mono (acryloyl). Oxyethyl) acid phosphate,
Mono (methacryloxyethyl) acid phosphate,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and the like can be mentioned.
Needless to say, the present invention is not limited to the above specific examples.

Examples of other non-fluorine-containing α, β-ethylenically unsaturated monomers include α, β-unsaturated groups at one end or both ends of polysiloxanes via a divalent linking group, That is, examples thereof include those in which any one of a vinyl group, an acryloyl group, and a methacryloyl group is linked. As a specific example, the general formula (B-1)

[0121]

[Chemical 28]

[Wherein, R 6 and R 7 are alkyl groups having 1 to 20 carbon atoms or phenyl groups, which may be the same or different, and may be the same or different for each siloxy unit, and p is 3 To 520, q is 0 or 1
In it, Y2 is a divalent linking group, -CH ₂ CH (OH)
_{CH 2 OCO -, - (CH} 2) n1NHCH 2 CH (OH) C
_{H 2 OCO -, - (CH} 2) n1OCO -, - (CH 2) n1-O
- (CH ₂₎ m1OCO-, or -OCH ₂ CH (OH) CH
₂ OCO- [However, n1, m1 is an integer of 2-6, R is the same as defined above, Z2 is methyl group, phenyl group, or a _{CH 2 = C (R) -} (Y2) q - is . ] The compound represented by or general formula (B-2)

[0123]

[Chemical 29]

[In the formula, R6 ′, R6 ″, R6 ′ ″, R6
7 ', R7 ", R7'", R8 ', R8 ", R8'"
Is an alkyl group having 1 to 20 carbon atoms or a phenyl group, which may be the same or different, and r, s and t are 1 to 2
An integer of 00, which may be the same or different,
Y2, q and R are as defined above. ] The compound represented by these is mentioned.

The following are more specific examples of the monomer containing a polysiloxane chain.

[0126]

[Chemical 30]

[0127]

[Chemical 31]

[0128]

[Chemical 32]

[0129]

[Chemical 33]

However, Me and Ph respectively represent a methyl group and a phenyl group, respectively. As the α, β-unsaturated group of the monomer containing a polysiloxane chain, any of a vinyl group, an acryloyl group and a methacryloyl group is possible, but an acryloyl group or a methacryloyl group is superior in terms of polymerization reactivity. Therefore, those containing these are particularly preferable.

According to the findings of the present inventors, the above-mentioned polysiloxane chain-containing monomers (B-1) and (B-2) are used in combination with the fluorine-based monomer according to the present invention and copolymerized. As a result, the abrasion resistance and impact resistance of the polymer as well as the scratch resistance to the photosensitive drum can be remarkably improved, and the durability as a carrier can be improved.

The method for producing a fluorine-containing polymer according to the present invention, which comprises polymerizing an ethylenically unsaturated monomer having two or more fluorinated alkyl groups and, if necessary, a non-fluorine-containing monomer, There is no limitation, and it can be produced by a known method, that is, a radical polymerization method, a cationic polymerization method, an anionic polymerization method or the like, and a solution polymerization method, a bulk polymerization method, or an emulsion polymerization method. Is simple and industrially preferable. In this case, as the polymerization initiator, those known in the art can be used, for example, benzoyl peroxide, peroxides such as diacyl peroxide, azo compounds such as azobisisobutyronitrile and phenylazotriphenylmethane. , A metal chelate compound such as Mn (acac) 3, and the like, and if necessary, lauryl mercaptan, 2
-A chain transfer agent such as mercaptoethanol, ethylthioglycolic acid, octylthioglycolic acid or the like, and a coupling group-containing thiol compound such as γ-mercaptopropyltrimethoxysilane are also used in combination with the chain transfer agent. It is possible to According to the knowledge of the present inventors, when such a coupling group-containing chain transfer agent is used in combination, the adhesion to the core material and the durability as a carrier can be improved. The fluorine-based random or block copolymer according to the present invention can also be obtained by photopolymerization in the presence of a photosensitizer or a photoinitiator, or polymerization using radiation or heat as an energy source.

The polymerization can be carried out in the presence or absence of a solvent, but it is more preferable in the presence of a solvent from the viewpoint of workability. Examples of the solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate and butyl acetate, polar solvents such as dimethylformamide and dimethyl sulfoxide, 1,1,1-trichloroethane and chloroform. Any of halogenated solvents, ethers such as tetrahydrofuran and dioxane, aromatics such as benzene, toluene and xylene, and fluorinated inner liquids such as perfluorooctane and perfluorotri-n-butylamine can be used. .

The copolymerization composition ratio of the fluorine-based monomer and the non-fluorine-based monomer of the polymer according to the present invention is usually 1 by weight.
It is 00:00 to 1: 1000, preferably in the range of 2: 1 to 1: 100, and 49:51 to 1: 100 is related to various properties as the coating material for the core material shown in the present invention, that is, coating workability. It is particularly preferable in that the polymer of the present invention exhibits the solvent solubility, the charging property, and the economical efficiency related to the fluorine content in the polymer.

The molecular weight of the fluoropolymer according to the present invention is preferably Mn = 2,000 to 1,000,000, and particularly preferably Mn = 3,000 to 100,000. The fluoropolymer according to the present invention can be used alone as a core material coating agent to form a carrier, but can be used in combination with a conventionally known carrier-core material coating resin.

The conventionally known carrier-core material coating resins include poly (tetrafluoroethylene), poly (vinylidene fluoride), poly (ethylene / tetrafluoroethylene) copolymer, poly (vinylidene fluoride / tetrafluoro). Fluorinated olefins such as ethylene) copolymer, poly (tetrafluoroethylene / hexafluoropropylene) copolymer, poly (vinyl fluoride ether), and poly (vinyl fluoride ether / terafluoroethylene) copolymer The resin is a fluororesin such as poly (fluorinated acrylate) or poly (fluorinated methacrylate) generally disclosed in the above-mentioned patent publications. Further, all of the general solvent-soluble resins and thermoplastic resins called binder resins or binder resins can be used. Specifically, styrene,
Styrenes such as chlorostyrene, vinyl styrene, p-methyl styrene, p-methoxy styrene, ethylene,
Propylene, butylene, olefins such as isobutylene, vinyl acetate, vinyl propionate, vinyl esters such as vinyl benzoate, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, methyl methacrylate, Ethyl methacrylate, butyl methacrylate, octyl methacrylate, dodecyl methacrylate, α, β-ethylenically unsaturated monocarboxylic acid esters, dibutyl fumarate, dimethyl fumarate, etc. α, β-ethylenically unsaturated Diester of dinocarboxylic acid, vinyl methyl ether,
Examples thereof include homopolymers or copolymers of vinyl ether such as vinyl ethyl ether and vinyl butyl ether, vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone, and a typical binder or binder. As the wearing resin, poly (methyl methacrylate), poly (styrene), poly (ethylene), poly (propylene), poly (styrene / methyl methacrylate / butyl acrylate) copolymer, styrene-
Examples include alkyl acrylate copolymers, styrene-alkyl methacrylate copolymers, poly (styrene / butadiene) copolymers, poly (styrene / maleic anhydride) copolymers, poly (styrene / acrylonitrile) copolymers, and the like. To be Further, polyester, polyurethane, epoxy resin, silicone resin, polyamide, alkyd resin, phenol resin, modified rosin, paraffin, wax and the like can be mentioned.

When the polymer of the present invention and the conventionally known coating resin are blended and used, the mixing ratio thereof is not particularly limited, but generally 5:95 to 100 by weight. : 0 is preferable.

In addition to the above, in the core material coating resin according to the present invention, if necessary, those conventionally known as additives for carriers, such as dyes, pigments, plasticizers, linoka powder, fillers, and fluorine are included. A systemic, hydrocarbon-based, or silicone-based surfactant can be added.

The core material particles according to the present invention can be coated with a coating resin by a solution coating method using a spray dry method or an emulsion coating method, or a direct surface polymerization method. . In the case of the solution coat method, the solvent exemplified as the above-mentioned polymerization solvent can be used. Further, in this case, the concentration or viscosity of the solution can be set arbitrarily.

The thickness of the coating material layer on the surface of the core material is usually 0.01 to 30 μm in a dry state, preferably 0.05.
10 to 10 μm. If the coating material layer is too thick, it may be easily peeled off from the core material.

[0141]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, all parts and% are based on weight unless otherwise specified.

First, each raw material and intermediate used will be outlined. (1): Polyisocyanate "Bernock DN-980S" (manufactured by Dainippon Ink and Chemicals, Inc., isocyanurate ring-containing polyisocyanate obtained using hexamethylene diisocyanate; isocyanate group content = 21.0%); Hereinafter, this is referred to as PI-1.

"Bernock DN-750" [manufactured by Dainippon Ink and Chemicals, Inc., 75% ethyl acetate solution of toluene diisocyanate / adduct type polyisocyanate; solid group-equivalent isocyanate group content = 17.3
%]; Hereinafter, this is referred to as PI-2.

"Bernock 9-409" (Polyphenyl diphenylmethane diisocyanate manufactured by Dainippon Ink and Chemicals, Inc .; isocyanate group content 3
1.0%; hereinafter referred to as PI-3.

“Burnock DN901S” (manufactured by Dainippon Ink and Chemicals, Inc., isocyanurate ring-containing polyisocyanate obtained using hexamethylene diisocyanate; isocyanate group content = 23.5
%]; Hereinafter, this is referred to as PI-4. (2): Polyol Polycaprolactone polyester triol having a hydroxyl value of 168.5, obtained by polycondensation reaction of trimethylolpropane and ε-caprolactone;
This is designated as PO-1.

Polypropylene glycol having a hydroxyl value of 160.3; hereinafter referred to as PO-2. (3): Polyamine compound Ethylenediamine; hereinafter abbreviated as EDA.

Isophoronediamine; hereinafter abbreviated as IPDA. Synthesis Example 1 <Synthesis of Polyester Polyol Containing Sulfonate Base> 5 parts of 148 parts of sodium sulfisophthalic acid, 114.4 parts of neopentyl glycol, and 0.08 part of zinc acetate are added.
The mixture is placed in a 00 mL four-necked flask and transesterified at 190 ° C. for 6 hours to obtain an intermediate.

Next, 16.3 parts of this intermediate, 139.4 parts of neopentyl glycol, 153.3 parts of adipic acid and 0.1 part of dibutyltin oxide were charged into a 500 ml four-necked flask, and the temperature was raised to 220 ° C. over 6 hours. Raise the temperature to 6
An esterification reaction was carried out at a temperature of 220 ° C. to obtain a polyester polyol containing a sodium sulfonate group having an acid value of 5.0 and a hydroxyl value of 132.6.

Synthesis Example 2 <Synthesis of Fluorine-based Copolymer> A glass flask equipped with a stirrer, a condenser, and a thermometer was used, and 45 parts by weight of the fluorine-based monomer A-1-1 was added thereto. ) 50 parts by weight, β-
Hydroxyethyl methacrylate (hereinafter, β-HEMA
5 parts by weight) and 233 parts by weight of methyl isobutyl ketone (hereinafter abbreviated as MIBK) were charged, and azobisisobutyronitrile (hereinafter abbreviated as AIBN) was used as a polymerization initiator in a nitrogen gas stream under reflux. After 1 part by weight and 0.2 part by weight of lauryl mercaptan as a molecular weight modifier were added, the mixture was refluxed for 7 hours to complete the polymerization.

The polystyrene conversion molecular weight of this polymer by gel permeation chromatography (hereinafter abbreviated as GPC) was Mn = 9,800. (This copolymer is referred to as Polymer 1.) Synthesis Examples 3 to 19 Fluorine was produced in the same manner as in Synthesis Example 2 except that various fluorine-based monomers and non-fluorine-based monomers were used in the ratios shown in Table 1. A system copolymer solution was obtained. These polymers are polymers 2-1 respectively.
7 The results of measuring the molecular weight of these polymers are shown in Tables 1 and 2.

[0151]

[Table 1]

[0152]

[Table 2]

However, the abbreviations in the table indicate the following compounds. MMA: methyl methacrylate n-BMA: n-butyl methacrylate SMA: stearyl methacrylate β-HEA: β-hydroxyethyl acrylate AA: acrylic acid 2-AM-2MPSA: 2-acrylamidophosphomethylpropanesulfonic acid MAEP: Mono (acryloyloxyethyl) acid phosphate MPTMSi: γ-methacryloxypropyltrimethoxysilane St: Styrene n-BA: n-Butyl acrylate 2EHA: 2-Ethylhexyl acrylate F17A: C ₈ F ₁₇ CH ₂ CH ₂ OCOCH = CH ₂ Production Example 1 <Production of core particles (A)> Magnetite MAT-305 (manufactured by Toda Kogyo Co., Ltd.) 10
0 parts, Shin-Etsu Chemical silane coupling agent KBM803
(Γ-mercaptopropyltrimethoxysilane) 0.5
Parts and 200 parts of acetone were mixed and stirred in a 500 ml beaker, and then acetone was distilled off to obtain magnetite treated with a silane coupling agent.

In a 1,000 ml flask, "Fuji HE
An aqueous phase was prepared by dissolving 19 parts of "CAL-15F" (hydroxyethyl cellulose manufactured by Fuji Chemical Co., Ltd.) in 356 parts of water.

In a separate container, 18.1 parts of PI-1 and P
11.4 parts of O-1, 70.5 parts of the silane coupling agent-treated magnetite obtained above, and 20 parts of toluene
And parts to form an organic phase.

At 20 ° C., using a homomixer,
While the aqueous phase was stirred at 7,000 to 7,500 rpm, an organic phase prepared in advance was charged therein and stirred for 1 minute to obtain a suspension dispersion liquid.

Then, this suspension dispersion was transferred to another flask, 0.1 part of dibutyltin dilaurate (DBTDL) was added while stirring at 200 rpm by a paddle type stirring blade, and 2 minutes later, further, 1.4 parts of a 50% aqueous solution of EDA was charged.

After keeping at room temperature (about 25 ° C.) for 2 hours,
The temperature was raised to 50 ° C. and the reaction was continued for 1 hour and further at 80 ° C. for 2 hours. After completion of the reaction, washing with water, filtration, drying and crushing were carried out to obtain desired carrier core particles.

The average particle size of the core particles was 24 μm. Comparative Production Example 1 <Production of Core Particles (R)> Styrene acrylic resin 2 having a weight average molecular weight of 30,000
9.5 parts and 70.5 parts of magnetite MAT305 were melt-kneaded using a pressure kneader, pulverized with a turbo mill,
By classification, a magnetic carrier having an average particle diameter of 25 μm was obtained.

Production Example 2 <Production of Core Particle (B)> The intended core carrier particles were obtained in the same manner as in Production Example 1 except that the formulation was changed as described below.

That is, as the water phase, "P
VA-205 "[partially saponified polyvinyl alcohol manufactured by Kuraray Co., Ltd.], 9 parts of" PVA-217 "(same as above) and 356 parts of water were used. 26.7 copies of PI-2, PO-1
No. 7.6 parts, 2 parts of the polyester polyol (E) described in Synthesis Example 1, magnetite is untreated magnetite M.
70.4 parts of AT305 and 10 parts of toluene were used, 0.18 parts of DBTDL was used as the urethanization catalyst, and ED was used as the polyamine.
2.5 parts of a 25% aqueous solution of A were used. The reaction product was filtered with filter paper, washed with water, packed in a column, flowed with 5% ferric chloride aqueous solution for ion exchange, and sufficiently washed with water to obtain core carrier particles. The average particle diameter of this product was 28 μm.

Production Example 3 <Production of Core Particles (C)> Target core carrier particles were obtained in the same manner as in Production Example 1 except that the formulation was changed as described below.

That is, as the water phase, "P
9 parts of "VA-205", 10 parts of "PVA-217" and 273 parts of water were used, while the organic phase was 15.0 parts of PI-3 and 12.8 parts of PO-2, respectively. 0.6 parts of dimethylolpropionic acid and 15 parts of toluene
And 71.6 parts of the silane coupling agent-treated magnetite described in Example 1 as the magnetite, 0.18 parts of DBTDL as the urethanization catalyst, and polyamine as the polyamine. IP
Fully crosslinked polymer particles were obtained by using 7.8 parts of a 30% aqueous solution of DA. The average particle diameter of this product was 24 μm.

Production Example 4 <Production of Core Particle (D)> The intended core carrier particles were obtained in the same manner as in Production Example 1 except that the formulation was changed as described below.

That is, as the water phase, "P
0.15 parts of VA-420 "and 340 parts of water were used, while the organic phase was 19.
9 parts, 1 part of PO-1, 1.9 parts of the polyester polyol described in Synthesis Example 1 and 28 parts of toluene are used, and the magnetite is 71 parts of the silane coupling agent-treated magnetite described in Example 1. .6 parts, and as a urethane-forming catalyst, 0.003 of DBTDL
Parts, and as the polyamine, 25 parts of EDA
% Solution in water was used. The rotation speed of the homomixer is 4
It was carried out at 500 to 5000 rpm. The average particle diameter of this product was 55 μm.

Examples 1 to 15 Core materials coating solutions were prepared by dissolving 15 g of each solid content of each of the polymers 1 to 15 shown in Synthesis Examples 2 to 19 in 500 g of acetone-methyl ethyl ketone (weight ratio 1: 2). did. Production Example 1 using this solution as carrier core particles
1 kg of the core particles shown in 4 to 4 were coated using a fluidized bed apparatus to prepare the resin-coated carrier of the present invention. The coating film thickness was about 1 to 3 μm, and it was confirmed from the surface analysis by ESCA that the fluoropolymer of the present invention was coated in any system.

The coated carrier 100 thus prepared
84 parts by weight of styrene / n-butyl methacrylate as a binder resin, 10 parts by weight of carbon black (BPL made by Cabot), 2 parts by weight of a charge control agent (Bontron N04 made by Orient), and polyethylene wax (Mitsui). 4 parts by weight of 400P) manufactured by Petrochemical Co., Ltd. was blended and mixed with 8 parts by weight of toner having an average particle size of 10 μm produced by a kneading and pulverizing method to prepare a two-component developer.

Toughness of carrier-coating layer (impact resistance,
Wear resistance and adhesion to the core material) are
Put 100g in a plastic container with a cap of 100cc, and turn the pot mill (grind master,
After being stirred for 24 hours at a rotation speed of 100 rpm on a bio gallery), the state of the coating material layer was observed by an electron microscope and evaluated.

The toner charge amount of the electrostatic image developer is a blow amount.
Off powder charge amount measuring device (Toshiba Chemical Co., TB-2
00 type) was used and the measurement was performed on a sample 3 minutes after stirring. The copying test was carried out using a modified EP430Z machine manufactured by Minolta Co., Ltd., and the images of the 1,000th sheet, the 5,000th sheet and the 30,000th sheet were evaluated after copying.

The results obtained are summarized in Table 3. In both cases, good adhesion and durability are exhibited. Comparative Examples 1 and 2 Conventional polymer 1 polymerized using an ethylenically unsaturated monomer having only one fluorinated alkyl group in one molecule.
6 and 17 were coated on the core particles (C) according to the present invention to prepare carrier particles. Table 4 shows the result of a copy test using the carrier particles. It can be seen from Table 4 that the adhesion, chargeability and durability are poor.

Comparative Example 3 An attempt was made to coat the surface of a conventional magnetic substance-dispersed carrier (R) in the same manner as in Example 1, but the resin component of the core particles (R) was dissolved in a solvent, and coating was performed. The particles were blocked inside and the coated carrier could not be manufactured.

Comparative Example 4 The core particles (R) were used as they were as carrier particles, but as shown in Table 4, the chargeability was poor.

Comparative Example 5 A spherical Ni-Zn ferrite core (referred to as R2) having an average particle diameter of 30 μm was coated with a resin. It can be seen from Tables 3 and 4 that the adhesion to the fluororesin is slightly inferior to the core particles according to the present invention.

[0174]

[Table 3]

[0175]

[Table 4]

Also in the carrier obtained by using the fluorine-based polymer according to the present invention and the binder resin composed of the copolymer of styrene-MMA-n-BA in combination, the same good result as above can be obtained. Was obtained, and its performance was superior to that of a carrier prepared by using a conventional fluororesin and the binder resin in combination.

As can be seen from the results of Example 11 in Table 3 and Comparative Example 1 in Table 4, an ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule was polymerized as an essential component. An electrostatic charge image developer comprising a carrier for developing an electrostatic charge image using a polymer as a coating resin and a toner must have a conventional ethylenically unsaturated monomer having only one fluorinated alkyl group in one molecule. It has much better charging property than that using a polymer polymerized as a component.

In addition, a conventional polymer obtained by polymerizing an ethylenically unsaturated monomer having only one fluorinated alkyl group in one molecule as an essential component with a higher polymerization ratio of the component was used in the same manner. It can be seen that the electrostatic charge image developer comprising the carrier for developing an electrostatic charge image and the toner is inferior in toughness of the film, and the polymer falls off from the core material and cannot be used for a long time.

[0179]

According to the present invention, as a coating material for core particles of a carrier for developing an electrostatic charge image, a polymer obtained by polymerizing an ethylenically unsaturated monomer having two or more fluorinated alkyl groups in one molecule as an essential component is used. Since the combination is used, the electrostatic image developer composed of the carrier and the toner is a conventional polymer obtained by polymerizing an ethylenically unsaturated monomer having only one fluorinated alkyl group in one molecule. In comparison with that, the core material particles of the present invention have a strong urethane urea cross-linking structure in which the magnetic material is dispersed extremely well, and therefore, the two particles work together. As a result, the core material and the covering material have good adhesion, and a particularly remarkable effect that they can be used for a long time is exhibited.

[Brief description of drawings]

 (Photo as substitute for drawing) Shape and structure of carrier particles

FIG. 1 is a scanning electron micrograph of a magnetic carrier of Example 13.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Hashimoto 4-21-4-208 Momoyamadai, Sakai City, Osaka Prefecture (72) Inventor Seishi Takano 3-418-1 Hamajera Showamachi, Sakai City, Osaka Prefecture

Claims (6)

[Claims] 1. A carrier for electrophotography comprising ferromagnetic fine particles and a resin, wherein the resin is composed of a core material and a coating material, and the core material has a composite crosslinked structure composed of urethane bond and urea bond. A magnetic carrier for electrophotography, wherein the coating material is urea and the coating material is a polymer obtained by polymerizing an ethylenically unsaturated monomer having two or more fluorinated alkyl groups as an essential component. 2. The core material contains one or more polar groups selected from the group consisting of sulfonic acid groups, sulfonic acid groups, carboxylic acid groups, and carboxylic acid groups. The magnetic carrier for electrophotography according to claim 1. 3. An ethylenically unsaturated monomer having two or more fluorinated alkyl groups having a structure in which two or more fluorinated alkyl groups are bonded to the same carbon atom or nitrogen atom. The magnetic carrier for electrophotography according to claim 1 or 2, wherein 4. An ethylenically unsaturated monomer having two or more fluorinated alkyl groups has at least two monovalent groups containing a fluorinated alkyl group, all of which are the same carbon atom or nitrogen atom. Is a polymerizable ethylenically unsaturated monomer having a skeleton bonded to, and at least one monovalent group containing a fluorinated alkyl group is present between the carbon atom or nitrogen atom and the fluorinated alkyl group. The monomer which is a monovalent group also having a polar atomic group, according to claim 1.
Magnetic carrier for electrophotography according to item 5. A main component comprising a ferromagnetic fine particle and a polyol having one or more polar groups selected from the group consisting of a sulfonic acid group, a sulfonic acid group, a carboxylic acid group, and a carboxylic acid group. An ethylenically unsaturated monomer having two or more fluorinated alkyl groups on the surface of a core material obtained by suspending and dispersing a mixture containing a polyol and a polyisocyanate in water containing a polyamine and polymerizing the mixture. A method for producing a magnetic carrier for electrophotography, which comprises coating a polymer obtained by polymerizing the body as an essential component. 6. After synthesizing the core material, 50% or more of the alkali metal cation of the polar group present on the surface of the core material is selected from the group consisting of hydrogen ion, divalent or higher valent metal cation, and organic cation. 6. The method for producing a magnetic carrier for electrophotography according to claim 5, further comprising ion-exchange with one or more cations and then coating with a polymer.