JPH0458017B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a capsule toner used for developing an electrostatic latent image in electrophotography or electrostatic printing. Conventionally, as an electrophotographic method, U.S. Patent No. 2297681
specification, Japanese Patent Publication No. 42-23910 (U.S. Patent No.
A number of methods are known, as described in Japanese Patent Publication No. 3666363) and Japanese Patent Publication No. 43-24748 (U.S. Patent No. 4071361), but generally they utilize photoconductive substances, An electrical latent image is formed on the photoreceptor by various means, and then the latent image is developed using toner. After the toner image is transferred to a transfer material such as paper as necessary, heat, pressure, or Copies are obtained by fixing with solvent vapor or the like. Various developing methods are also known for visualizing electrical latent images using toner, and these can be broadly classified into dry developing methods and wet developing methods. The former method is further divided into methods using a two-component developer and methods using a single-component developer. Among the two-component developing methods, the magnetic brush method using an iron powder carrier, the cascade method using a bead carrier, etc. are widely put into practical use, depending on the type of carrier for conveying the toner. All of these methods are excellent methods that can produce good images relatively stably, but on the other hand, they have common drawbacks associated with two-component developers, such as carrier deterioration and image fluctuations due to fluctuations in the toner and carrier mixing ratio. has. In order to avoid these drawbacks, various development methods using a one-component developer consisting only of toner have been proposed, and among them, many excellent methods using magnetic toner have been put into practical use. A developing method that uses a magnetic one-component developer is the MagneDry method that uses conductive toner, but although this method is stable during development, it has poor transferability on transfer materials such as plain paper. There's a problem. Therefore, as a method using a high-resistance magnetic toner with good transferability, there is a method using dielectric polarization of toner particles as described in JP-A-52-94140 (West German Patent No. 2704361), and JP-A-53-31136. There is a method of transferring charge by disturbing toner, etc., as disclosed in US Pat. No. 4,121,931, but there is a problem with the stability of development. In addition, as developing methods proposed by the present applicant in recent years,
A method of developing a latent image by flying toner particles as disclosed in Japanese Patent No. 18656 has been put into practical use. This involves applying a very thin layer of magnetic toner onto the sleeve, triboelectrically charging it, and then developing it by facing the electrostatic image very close to, but not in contact with, the electrostatic image under the action of a magnetic field. According to this method, by applying an extremely thin layer of magnetic toner onto the sleeve, the chances of contact between the sleeve and the toner are increased, and sufficient frictional electrification is possible. By moving the toner relatively, the toner particles are disaggregated and are sufficiently rubbed against the sleeve, and the toner is supported by magnetic force and developed by facing the electrostatic image without coming into contact with it. By preventing background fog, etc., excellent images can be obtained. The most common method for fixing the developed toner image is to heat it with an infrared heater or a heated roller, and fuse it to the support. There is a shift towards pressure fixing using rigid rollers. Toner materials are selected to suit each fixing method, and toners used in a particular fixing method generally cannot be used in other fixing methods. In particular, it is impossible to reuse toner for heat-melting fixing using an infrared heater as toner for fixing with a heat roller, and furthermore, there is almost no compatibility between toner for heat fixing and toner for pressure fixing. Therefore, toners suitable for each fixing method have been researched and developed, and toners for one-component pressure fixing methods have been further improved. The method of fixing toner by applying pressure has the following advantages: there is no risk of burning the copy sheet, copying can be done without waiting time when the copier is turned on, high-speed fixing is possible, and the fixing device is simple. There are many advantages such as For such a toner that can be fixed by pressure, the constituent resin must have characteristics suitable for pressure fixing, and resins suitable for this purpose are actively being developed. However, it has excellent pressure fixing properties,
There is no offset phenomenon to the pressure roller, the developing performance and fixing performance are stable even after repeated use, there is no adhesion to the carrier, metal sleeve, or photoreceptor surface, and there is no aggregation or agglomeration during storage. A practical pressure fixing toner that does not form a cake and has good storage stability has not been obtained. In particular, problems remain in the fixability to plain paper in terms of the pressure fixing method. Various capsule-type toners having hard resin shells have also been proposed. For example, there are capsule toners with a soft material core as seen in JP-A-54-8104 (U.S. Pat. No. 3,788,994), and capsule toners with a soft resin solution core, but they have a pressure fixing ability. There are many unresolved problems such as shortage and offset phenomenon, and it has not been put into practical use. Furthermore, the above-mentioned capsule toner causes variations in the amount of charge generated on the surface of the capsule toner particles between the particles or between the capsule toner and a toner carrier such as a sleeve, resulting in development fogging, toner scattering, etc. failure is likely to occur and charge control is unstable. Furthermore, these phenomena become particularly noticeable when the number of copies is increased, resulting in a result that is practically unsuitable for copying machines. The present invention provides a capsule toner that does not have the drawbacks mentioned above. Particularly, an object of the present invention is to provide a capsule toner that exhibits excellent charge controllability and stable charge controllability. Further, the present invention provides a pressure fixing capsule toner that has good fixing properties on plain paper at a lower pressure than conventional ones, and has stable developing performance and fixing performance even when copying a large number of sheets. It is something. A further object of the present invention is to provide a pressure-fixable capsule toner with excellent developability and transferability. Furthermore, the present invention shows good pressure fixing properties even when used as a magnetic toner for a one-component developer containing magnetic fine powder, and shows good magnetic properties and is capable of electrostatic transfer. The present invention provides a capsule toner with sexual characteristics. A feature of the present invention is that in a capsule toner composed of a core material and an outer shell that covers the whole or a part of the core material, the outer shell has a general formula: [In the formula, R ₁ represents C ₀ to C ₁₂ alkylene,
R ₂ and R ₃ represent a hydrogen atom or a C ₁ to C ₂₀ alkyl group. ] An aminostyrene-styrene copolymer produced from the above aminostyrene or a derivative thereof, or a quaternary ammonium salt thereof, and styrene (copolymerization molar ratio 1/9 to 9/ 5) A capsule toner characterized by containing the following. The method for manufacturing the capsule toner of the present invention can utilize various known encapsulation techniques. For example, spray drying method, interfacial polymerization method, coacervation method, phase separation method, in-situ polymerization method, etc. are described in U.S. Patent Nos. 3338991, 3326848, and 3502582. You can use the methods described. When constituting a pressure-fixable toner, the resin constituting the core material used in the present invention is preferably one that easily entangles with the fibers of plain paper under a linear pressure of about 20 kg/cm or less, and has a density of 0.94 Polyethylene or paraffin wax of g/cm ³ or more is preferred. As the polyethylene having a weight of 0.94 g/cm ² or more, it is particularly preferable to have a melt viscosity at 140°C of 600 CPS or less, and it is a so-called low molecular weight polyethylene or a polyethylene wax that is manufactured by a polymerization method or a decomposition method. It is something that The melt viscosity is less than 600CPS and the density is
Examples of commercially available polyethylenes with a density of 0.94 g/cm ³ or more include AC polyethylene #9 (manufactured by Allied Chemical) (0.94 g/cm ³ , 350 CPS) Hiwatux 310P (manufactured by Mitsui Petrochemical) (0.94 g /cm ³ ,250 CPS) Hiwatux 410P (Mitsui Petrochemicals) (0.94g/cm ³ ,550 CPS) 〃 405P (Mitsui Petrochemicals) (0.96g/cm ³ ,550 CPS) 〃 400P (Mitsui Petrochemicals) ) (0.97g/cm ³ , 550 CPS) etc. Examples of materials with a density of 0.94 g/cm ³ or more with a density of 150 CPS or less include the following. Hiwax 200P (manufactured by Mitsui Petrochemicals) (0.97 g/cm ³ , 70 CPS) Hoechst Wax PE130 (manufactured by Hoechst AG) (0.95 g/cm ³ , 117 CPS) In addition, paraffin waxes such as those shown in the following table are available. be.

【table】

【table】

[Table] In the present invention, it is preferable to use a suitable combination of the above-mentioned polyethylene having a density of 0.94 g/cm ³ or more and paraffin wax. Of course, you may combine several types of paraffin waxes if necessary. The blending ratio when the polyethylene and paraffin wax are combined is preferably 8/2 to 0/10, more preferably 6/4 to 1/9 by weight. As the coloring agent contained in the core material of the capsule toner of the present invention, known dyes and pigments can be used. For example, various carbon blacks, aniline blacks, naphthol yellows, molybdenum oranges,
Examples include rhodamine lake, alizarin lake, methyl violet lake, phthalocyanine blue, nigrosine methylene blue, rose bengal, and quinoline yellow. When the capsule toner of the present invention is used as a magnetic toner, magnetic powder can be contained in the core material. Magnetic powders include iron, cobalt,
These include ferromagnetic elements such as nickel or manganese, and alloys and compounds containing these elements such as magnetite and ferrite. This magnetic powder may also be used as a coloring agent. The content of this magnetic powder is 15 to 70 parts by weight per 100 parts by weight of all the resin in the core material. In the present invention, the outer shell covering all or part of the core material has the general formula [In the formula, R ₁ represents C ₀ to C ₁₂ alkylene,
R ₂ and R ₃ represent a hydrogen atom or a C ₁ to C ₂₀ alkyl group. ] An aminostyrene-styrene copolymer produced from aminostyrene or a derivative thereof represented by the above, or a quaternary ammonium salt thereof, and styrene (copolymerization molar ratio 1/9 to 9/5) ), but the preferred aminostyrene or derivatives of the aminostyrene are o-aminostyrene, m-aminostyrene, p-aminostyrene, m-N,N-dimethylaminostyrene, p-N, N-dimethylaminostyrene, p-
N,N-diethylaminostyrene, p-N,N-
Dipropylaminostyrene, p-N,N-dibutylaminostyrene, p-N-laurylaminostyrene, p-N-stearylaminostyrene, p-
Vinylbenzylethylamine, o-vinylbenzyldimethylamine, p-vinylbenzyldimethylamine, p-vinylbenzyldiethylamine, p
Examples include -vinylbenzyldipropylamine, p-vinylbenzyldibutylamine, p-vinylbenzyldiamylamine, etc., and these aminestyrenes or derivatives of the same aminestyrenes are substituted with alkyl halides or aryl halides. It can also be used as a quaternary ammonium salt. In addition, in the present invention, 1 having another vinyl group
The species or two or more monomers include styrene, O-methylstyrene, P-methylstyrene,
Styrenes such as 2,4-dimethylstyrene, P-n-butylstyrene, P-tert-butylstyrene, P-n-dodecylstyrene, P-chlorostyrene, P-phenylstyrene, vinylnaphthalenes, ethylene, propylene , ethylenically unsaturated monoolefins such as isobutylene; vinyl esters such as vinyl chloride, vinyl acetate, vinyl butyrate, vinyl benzoate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate , n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate,
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether Vinyl ethers such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinylindole, N-vinylpyrrolidone
Examples include vinyl compounds. Furthermore, in the present invention, the outer shell that covers all or part of the core material may contain other resins in a range of 95% by weight or less, such as polystyrene, polyP-chlorostyrene, polyvinyltoluene, etc. Homopolymers of styrene and its substituted products; styrene-P-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer Combined, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer,
Styrene-dimethylaminoethyl methacrylate copolymer, styrene-diethylaminoethyl methacrylate copolymer, styrene-dimethylaminopropylamide acrylate copolymer, styrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, Styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene- Styrenic copolymers such as acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene , polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyamide, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin , paraffin wax, etc. can be used alone or in combination. Example 1 The core materials were 20 parts by weight of Hiwax 200P (manufactured by Mitsui Petrochemicals), 80 parts by weight of Paraffin Wax 155 (manufactured by Nippon Seicho), and 60 parts by weight of magnetite at 150°C.
The mixture was melt-mixed using a spray dryer, granulated using a spray dryer, and then subjected to dry classification to obtain spherical particles with a particle size of 9.1 μ±4.5 μ. This core material was separated into P-N, N-
Dimethylaminostyrene-styrene copolymer (molar ratio 1/1) and styrene-dimethylaminoethyl methacrylate copolymer (molar ratio 9/1) [weight ratio of both copolymers 1/1], 0.3μ It was coated with a film thickness of . For 1g of this toner, iron powder (200
~300 mesh) was mixed and the amount of triboelectric charge was measured by a known measuring method, and it was found to be +11.0 μc/g. This capsule toner was then applied to a developer having a magnetic sleeve to develop a latent image with a negative electrostatic charge, which was then transferred onto high-quality paper. 2. Pressure can be applied to the transfer paper with the image from both ends.
When passed through a pressure fixing device consisting of a book pressure roller, it showed almost perfect fixing performance at a speed of 125 mm/sec and a linear pressure of 10 kg/cm. The image density was 1.2, and a good clear and reversed image with no fogging was formed. Furthermore, after a durability test of idling for 4 hours in the developing device, development and transfer were performed again, but the image density was 1.5 and the amount of triboelectric charge was +13.0μc/g, so there was little change in image quality. , good durability and stable charge control were observed. Comparative Example 1 The core material of Example 1 was mixed with styrene-methyl methacrylate copolymer (molar ratio 1/1) and styrene-methyl methacrylate copolymer (molar ratio 1/1).
Dimethylaminoethyl methacrylate copolymer (molar ratio 9/1) [weight ratio of both copolymers 1/
1] and coated with a film thickness of 0.3μ. When the same test as in Example 1 was conducted using this capsule toner, the initial triboelectric charge amount was +22.0 μc/g, but it increased to +30.5 μc/g after 30 minutes of idle rotation. In addition, an uneven phenomenon occurred, and furthermore, the image density decreased (0.6) and fogging occurred. Example 2 The same procedure as in Example 1 was carried out using 10 parts by weight of Hiwax 200P, 90 parts by weight of Paraffin Wax 155, and 5 parts by weight of Phthalocyanine Blue as core materials.
A blue core material with a particle size of 10.3 μm±5.0 μm was obtained.
This core material was dried using a spray drying method.
-N,N-diethylaminostyrene-styrene copolymer (mole ratio 1/1) and styrene-diethylaminoethyl methacrylate copolymer (mole ratio 9/1) [weight ratio of both copolymers 1/1] ,
When coated with a film thickness of 0.5 μm, the amount of triboelectric charge of this capsule toner was +16.4 μc/g.
This capsule toner was mixed with 200 to 300 meshes of iron powder at a weight ratio of 1/9 and used as a developer, and a test similar to Example 1 was conducted using a two-component development method. When the iron powder was removed and the amount of triboelectric charge was measured again, it was +19.3 .mu.c/g, indicating that the increase was small and good results were obtained with little change in image density and image quality. Comparative Example 2 The core material obtained in Example 2 was mixed with styrene-acrylonitrile copolymer (molar ratio 1/1) and styrene-diethylaminoethyl methacrylate copolymer (molar ratio 9/1) [both copolymers It was coated with a film thickness of 0.5μ at a weight ratio of 1/1]. When this capsule toner was subjected to the same test as in Example 2, the initial triboelectric charge amount was +15.7 μc/g, but it increased to +21.0 μc/g after 1 hour of idle rotation. , a significant decrease in image density and fogging occurred. Example 3 The core material obtained in Example 2 was separated into P-vinylbenzyldimethylamine-styrene copolymer (molar ratio 1/1) and styrene-methyl methacrylate copolymer (molar ratio 1/1) using a phase separation method. 1) When the capsule toner was coated with a film thickness of 0.3 μm at a weight ratio of 7/3, the amount of triboelectric charge of this capsule toner was +9.8 μc/g. This capsule toner was mixed with a negatively charged magnetic toner (toner for NP-120 manufactured by Canon) at a weight ratio of 1:1, and applied to a developing device having a magnetic sleeve. When similar tests were conducted, good results similar to those of the Examples were obtained.

Claims (1)

[Scope of Claims] 1. In a capsule toner for developing an electrostatic latent image that is composed of a core material and an outer shell that covers the whole or a part of the core material, the outer shell has the general formula [In the formula, R ₁ represents C ₀ to C ₁₂ alkylene,
R ₂ and R ₃ represent a hydrogen atom or a C ₁ to C ₂₀ alkyl group. ] An aminostyrene-styrene copolymer produced from the above aminostyrene or a derivative thereof or a quaternary ammonium salt thereof represented by styrene (copolymerization molar ratio 1/9 to
9/5) A capsule toner for developing electrostatic latent images.