JPS6159351A - Capsule toner - Google Patents

Abstract

PURPOSE:To obtain a toner which obviates the filming of a remaining toner during cleaning of a photosensitive body, has good fixability on plain paper as well under low pressure and has excellent durability by incorporating a fluoropolymer powder to the inside and outside of the capsule toner. CONSTITUTION:The capsule toner dispersed with the fluoropolymer powder to the core material or added externally with 0.001-10wt% the fluoropolymer to the surface of the shell of the core material incorporated with said powder at 0.1%-30wt% on the surface thereof in the locally existing state is manufac tured. PE, paraffin, wax, etc. which are liable to intertwine with the fibers of plain paper under about <=20kg/cm linear pressure are mixed preferably with the press fixing components of the core material. A (co)polymer resin of styrene, (meth)acryl, etc. is used for the shell. Hydrophobic colloidal silica, etc. are externally mixed with such capsule toner particles, by which the devel oper is obtd. The capsule toner which has the good press fixability and obviates the filming on the surface of the photosensitive body is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a toner used in electrophotography, electrostatic printing, magnetic recording, etc., and particularly to a toner suitable for pressure fixing.

[Prior art 1] Conventionally, as an electrophotographic method, US Pat.
(U.S. Pat. No. 3,888,383), Japanese Patent Publication No. 43-24748 (U.S. Pat. No. 4,071.
Although many methods are known, such as 3El1 Specification),
In general, a photoconductive substance is used to form an electrical latent image on a photoreceptor by various means, and then the latent image is developed using developer powder (hereinafter referred to as toner), and if necessary, it is printed on paper. After a toner image is transferred to a transfer material such as, it is fixed by heat, pressure, solvent vapor, etc. to obtain a copy.

Further, when a process of transferring a toner image is included, a cleaning process is usually provided to remove residual toner on the photoreceptor.

Toners for developing electrical latent images or magnetic latent images are conventionally prepared by melting and kneading a binder resin such as polystyrene, a coloring agent such as carbon black, and optionally additives. It is generally used after being crushed into a fine powder of about 5 to 20 liters. As described above, dry toners are generally manufactured by a dry method that does not use a solvent. On the other hand, in recent years, fixing methods using pressure rollers have been actively developed from the viewpoint of energy saving, and along with this, the development of toners having pressure fixing properties has become an important theme. However, with current toners, a good fixed image cannot be obtained unless a high pressure of about 30 kg/cn+ is applied between the pressure rollers. This may cause problems such as. Furthermore, since it is necessary to make the fixed image strong, it increases its size and cost. In this sense, it is desired to develop toners that fix with the lowest possible pressure. Various capsule-type toners with hard resin shells have been proposed as pressure-fixable toners. ing. for example,
There are capsule toners with a soft material core as seen in JP-A No. 54-8104, and capsule toners with a soft resin solution core as shown in JP-A-51-132838, but they lack pressure fixing ability and suffer from offset. There are many unresolved problems such as phenomena, and it has not been put into practical use. Furthermore, with the capsule toner described above, during cleaning, a thin layer of toner called filming is formed on the surface of the photoreceptor with a small amount of toner due to the frictional force acting between the cleaning member such as a brush or blade and the toner. This has the disadvantage that the photoreceptor characteristics change, such as increasing the residual potential of the photoreceptor, resulting in a decrease in image quality.

[Problem to be Solved by the Invention 1] An object of the present invention is to provide a capsule toner that solves the above-mentioned drawbacks.

In particular, it is an object of the present invention to have good fixing properties on plain paper at a lower pressure than conventional ones, and to prevent filming on the surface of the photoreceptor even when copying a large number of sheets. The present invention provides a capsule toner that provides high quality images.

Furthermore, it is an object of the present invention to provide a capsule toner that exhibits good pressure fixing properties and magnetism and can be electrostatically transferred even when it contains magnetic fine particles and is used as a magnetic toner for a one-component developer. This is what we provide.

According to the invention, there is provided a capsule toner comprising a core material and an outer shell covering the core material, wherein the core material and the outer shell of the capsule toner contain a fluorine-based material. A capsule toner containing a polymer powder is provided.

A capsule toner in which the core material contains a pressure component constitutes a preferred embodiment of the present invention.

The fluoropolymer in the present invention refers to a homopolymer of a fluoromonomer or a copolymer of a fluoromonomer and another intermediate, and specific examples thereof include, for example, 7
・Vinylidene chloride, polyvinyl fluoride, polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, chlorotrifluoroethylene-ethylene copolymer, tetrafluoroethylene/perfluoroethylene There are vinyl ether copolymers, tetrafluoroethylene-perfluorosulfonyl fluoride vinyl ether copolymers, etc., and these are used as powders having an average particle size of 3 to 0.01 pL, preferably 1 to 0.1 pL.

In the present invention, the fluoropolymer powder is contained in the capsule toner in a state of being dispersed within the core material or localized on the surface of the core material, and the amount added is usually 0.1 to 30% by weight. Although it is preferable, the optimum amount to be added should be determined according to the properties of the basic core material components, and outside the capsule toner,
It is contained in an attached state on the surface of the outer shell by various external addition methods, and the amount added is in the range of 0.001 to IO weight %.

If the amount of fluoropolymer powder added inside and outside the capsule toner exceeds each range, fixing performance and image density tend to decrease, which is undesirable, while below each range, it may be difficult to prevent filming on the photoreceptor. The effect is not sufficient.

In the present invention, the pressure fixing component has a linear pressure of 20 kg.
A material that easily entangles the fibers of plain paper under a pressure of about / cm or less is preferable, and polyethylene, paraffin, wax, etc. are preferable.

The polyethylene preferably has a melt viscosity of eoocps or less at 140° C., and is known as low molecular weight polyethylene or polyethylene wax, and is produced by a polymerization method or a decomposition method. Commercially available products with a melt viscosity of eoocps or less include, for example, AC polyethylene #8 (allied chemical acid) (0
,94g/cm3.350CPS) High Wax 31
0P (Mitsui Petrochemical) (0.94g/cm3.2
50CPS) High Wax 410P (Mitsui Petrochemical) (0.94g/cm3.550CPS) tt
405P (Mitsui Petrochemical) (0, Hg/c
m3.550CPS) tt 400P (Mitsui Petrochemical) (0,
l]? g/cm3.550CPS) High Wax 20
0P (Mitsui Petrochemical) (0.97g/CmA,
70CPS) Hoechst Wax PE130 (manufactured by Hoechst AC) (0.95g/cm3.!17GPS) There are also paraffin waxes as shown in the following table.

Table 2 Paraffin wax (manufactured by Nippon Seiro) In the present invention, the polyethylene and paraffin wax are preferably used in an appropriate combination. Of course, you may combine several types of paraffin wax as necessary.

The blending ratio when combining the polyethylene and paraffin wax is preferably 6/8 to 0/10 by weight.
/4～! /8 is good.

As the coloring agent contained in the core material of the capsule toner of the present invention, known dyes and pigments can be used. Examples include various carbon blacks, aniline black, naphthol yellow, molybdenum orange, 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.

Examples of magnetic powder include ferromagnetic elements such as iron, cobalt, nickel, or manganese, and magnetite containing these elements.
These include alloys and compounds such as ferrite. This magnetic powder may also be used as a coloring agent. The content of this magnetic powder is preferably 15 to 70 parts by weight based on 100 parts by weight of all the resins in the core material.

The core material of the capsule toner of the present invention can be prepared by, for example, melting and kneading the above-mentioned components, pulverizing them, or blowing them out in the form of a mist from a spray nozzle of a spray dryer and granulating them while cooling, and then, if necessary, By classifying, fine particles having an average particle size of 5 to 151j are prepared.

As the material for the outer shell, known resins can be used, such as the following resins consisting of 1,000 yen. Styrene and substituted products thereof such as styrene, P-chlorostyrene, and P-dimethylamino-styrene; methyl acrylate;
Esters of acrylic acid or methacrylic acid such as ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, N,N-dimethylaminoethyl methacrylate; maleic anhydride or half ester of maleic anhydride , half amide or diesterimide, bicolviridine,
Nitrogen-containing vinyl such as N-vinylimidazole; vinyl acetal such as vinyl formal and vinyl butytail;
These include vinyl monomers such as vinyl chloride, acrylonitrile, and vinyl acetate; vinylidene monomers such as vinyllidene chloride and vinylidene fluoride; and olefin monomers such as ethylene and propylene. Also, polyester, polycarbonate, polysulfonate, polyamide, polyurethane, polyurea, epoxy resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, melamine resin, polyphenylene oxide. Homopolymers, copolymers, or heptadolymers such as polyether resins or thioether resins can be used.

Various known encapsulation techniques can be used to produce the capsule toner. For example, spray drying method, interfacial polymerization method, coacervation method, phase separation method, 1n-situ polymerization method, U.S. Patent No. 3,338,99
The methods described in Specification No. 1, Specification No. 3.32fl, Specification No. 848, Specification No. 3,502,582, etc. can be used.

The capsule toner of the present invention thus obtained has a particle size of 0.01 to
The microcapsules have an outer shell with a thickness of 0.8 hi and an average particle size of 5 to 18 g.

Carbon black, various dyes and pigments, hydrophobic colloidal silica, etc. can be added or mixed with the capsule toner of the present invention for the purpose of charge control, imparting fluidity, coloring, etc.

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 Hiki Seiro), 60 parts by weight of magnetite, and 0.0 parts by weight of polyvinylidene fluoride 461 (manufactured by Pennwald). 8 parts by weight to 15
By melt-mixing at 0'O, granulating with a spray dryer, and performing dry classification, the particle size was 10.3g±5.0.
A spherical shape was obtained.

This core material was separated from the organic phase using styrene-dimethylaminoethyl methacrylate (mole ratio 90/
IO) Copolymer was coated with a film thickness of 0.41 L to obtain encapsulated particles.

Next, 1.2 g of hydrophobic colloidal silica (manufactured by Nippon Silikani Industry) and 4610.3 g of polyvinylidene fluoride were added to 300 g of the encapsulated particles using a coffee mill.
A developer was obtained by externally adding and mixing.

A copying test of 4000 sheets was conducted using this developer using a copying machine PC-20 (cannon acid, but the fixing device was modified to a pressure fixing device with a linear pressure of 12 kg/cm) using an OPC photoreceptor. The obtained image showed almost perfect fixation throughout the test without any filming on the body, the image density did not change, and a clear image without fog was formed, which was good. Ta.

Comparative Example 1 From Example 1, a developer was prepared using polyvinylidene fluoride 461 additive-free capsule toner by the same treatment as in Example 1, and a copying test was conducted. Although the resulting image had good fixability and image density, fogging occurred due to the filming and the image quality was significantly degraded.

Example 2 The core materials were 20 parts by weight of AC polyethylene #9 (manufactured by Allied Chemical), 80 parts by weight of paraffin wax 155 (manufactured by Nippon Seiro), 5 parts by weight of phthalocyanine blue, and hexafluoropropylene-tetrafluor. Oethylene copolymer TL-120 (Liquid Nitrogen
When granulated in the same manner as in Example 1 using 2 parts by weight (manufactured by Processing Co.), 9.8±4.7p was obtained.
A core material was obtained, and this was prepared in the same manner as in Example 1 to obtain nucleated particles.

Next, 300 g of these encapsulated particles were mixed with 3.0 g of hydrophobic colloidal silica and 1.0 g of TL-120, and
Furthermore, we mixed it with 80g of iron powder of 200-300 meshes to make a developer, and conducted a 4000-sheet copying test.
Similar to Example 1, good results were obtained.

Comparative Example 2 A developer was prepared in exactly the same manner as in Example 2 except that TL-120 was removed, and a copying test was conducted.
When no sheets were used, filming occurred on the photoreceptor and the image quality deteriorated.

[Effects of the Invention] As described above, the capsule toner according to the present invention has a capsule structure and contains fluoropolymer powder inside and outside, so it can be applied to plain paper under lower pressure than before. It has good fixing properties.

Furthermore, even if a large number of copies are made, no filming occurs on the surface of the photoreceptor, and high-quality images can be obtained. Further, the capsule toner of the present invention exhibits good pressure fixability and magnetism even when it is made into a one-component developing toner containing magnetic fine particles, and is characterized in that it can be electrostatically transferred.

Claims (2)

[Claims] (1) A capsule toner comprising a core material and an outer shell covering the core material, characterized in that the capsule toner contains a fluorine-based polymer powder inside and outside. (2) The capsule toner according to claim 1, wherein the core substance contains a pressure fixing component.