JPS59170854A - Developer for developing electrostatic latent image - Google Patents

Abstract

PURPOSE:To obtain an encapsulated toner suitable especially for pressure fixation and superior in development stability, durability, etc. by precipitating the first outer shell uniformly coating all the core material by adjusting pH without using any solvent dissolving the second outer shell. CONSTITUTION:A polymer having pressure fixability, such as low mol.wt. PE, is used for a core material, a magnetic powder is added in the case of a magnetic toner, the core material particles are dispersed into a soln. contg. casein and NH4OH, an aq. soln. of HCl is dropped to neutralize said soln. to uniformly precipitate said casein on the surface of each particle and thus form the first shell. Said particles are, after drying, dispersed uniformly into a DMF soln. of a styrene-dimethylaminoethyl metacrylate resin, and then water is dropped to precipitate the resin on the surface of each particle and thus form the second outer shell. When a soln. of acrylic acid polymer is used to form the first outer shell, the polymer is pptd. with a soln. of NH4OH. The encapsulated toner thus obtained is prevented from peeling off the outer shells, elution of the core material, agglomeration of the particles with each other, and offset phenomenon of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer used to develop an electrical latent image in electrophotography or electrostatic printing, and more particularly to a developer containing capsule toner suitable for pressure fixing. .

Conventionally, electrophotography methods include US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43
Many methods are known, as described in Japanese Patent No. 24.748, etc., but in general, a photoconductive substance is fully utilized to form an electrical latent image on a photoreceptor by various means. Next, the latent image R is developed using toner, and if necessary, an image is transferred to a transfer I of paper, etc., and then heat and pressure are applied.
3 or by fixing with a target vapor or the like to obtain a copy.

There is also a developing method that uses toner to visualize an electrical latent image in 11T.

For example, the magnetic brush method described in U.S. Patent No. 2,874,063 (91 specification), the cusp-1 development method described in U.S. Pat. A number of developing methods are known, such as the powder method, fur brush developing method, and liquid developing method described in No. 221,776.

As toners used in these developing methods, fine powders in which dyes and pigments are completely dispersed in natural or synthetic resins have conventionally been used. Furthermore, it is also known to use fine developing powder to which a third substance is added for various purposes.

The developed toner image is transferred and fixed on a transfer material such as paper, depending on the need.

To fix the toner image, use a full toner heater or
lJ) is a method in which the binder resin of toner 1 is completely softened or melted with an organic solvent and fixed on the support by heating and melting with a hot hole etc. Knowledge of how to fix it on the support etc. 2
I'm here.

Toner TD, materials are selected to suit each fixing method,! Toners used in fixed fixing methods generally cannot be used in other fixed fixing methods. However, it is almost impossible to transfer the toner used in the conventionally widely used heater rolling heat fusion fixing method to the hot roller constant fixing method, solvent fixing method, pressure fixing method, etc. Therefore, research and development have been carried out on +1 and - suitable for each fixing method.

Dogs - Method of colonization by full pressure US/Permit No. 3,
269.626, Japanese Patent Publication No. 46-15876, etc., it is energy saving, pollution free, copying can be done without waiting time by using the power supply of the copying machine 7'17, and copying is possible without waiting time. This method has many advantages such as no risk of burning, high-speed fixing, and simple fixing device.

However, there are also problems with toner fixability and the set phenomenon of pressure rollers, and various research and developments are being carried out to improve the pressure fixability. For example,
Japanese Patent Laid-open No. 9880 discloses a pressure fixing toner containing an aliphatic component and a thermoplastic resin;
No. 75032 describes a capsule-shaped pressure constant danger 1-su with a soft material in the core, and JP-A No. 48
-75033 describes a pressure fixing toner using a black copolymer of a tenacious polymer and a soft polymer.

However, it is easy to manufacture, has sufficient pressure fixing performance, does not cause offset to the pressure roller, and has stable development and fixing performance even after repeated use. , does not cause adhesion to the photoreceptor surface,
A practical pressure fixing toner that does not aggregate or form cakes during storage and has good storage stability has not yet been obtained.

For example, pressure fixing toner made of a soft material has good pressure fixing properties, but it is difficult to finely pulverize to form a toner, and it tends to cause offset to the pressure roller, causing damage to the roller and photoconductor. There are many problems such as easy adhesion to the surface and aggregation and cake formation during storage.

In addition, hard resins are easy to form into toners, and toners with excellent chargeability and storage stability are easily obtained, but pressure fixability is extremely poor. (') This is because the hard resin is harder than the cellulose fibers that make up the entire paper, so when pressure is applied, it is simply crushed inside the paper and does not end up getting entangled with the fibers. .

- In addition, in various conventional pressure fixing capsule toners, if a soft material with good pressure fixing properties is used as the core material, as the pressure fixing is repeated, pressure is applied gradually. This is undesirable as it causes offset and curling of the transfer paper, and if such phenomena are avoided, the pressure fixing performance deteriorates. Also,
The manufacturing process of Kabuji Lutoner is generally complicated, and it is necessary to take into consideration the removal of loose shell material, and a practical capsule toner has not yet been obtained.

That is, there are several problems associated with the manufacturing method of capsule toner. One of the criteria for selecting all materials is to ensure that the core material is not dissolved in the temporary phase solution at room temperature, except for the core material being completely dispersed in the shell material solution. The reason for this is that it is extremely narrow.

Furthermore, recently, a method has been used in which the electrostatic latent image is fully developed using a one-component developer that contains all the magnetic fine particles in l/i+-chi and does not use gear particles, but in this case, the toner adhesive resin This requires dispersibility and adhesion with magnetic fine particles, as well as impact resistance and fluidity of the toner, and it is extremely difficult to achieve both high pressure fixing performance.

The present invention is different from conventional pressure fixing l/su particles and provides a pressure fixing developer which does not have the disadvantages mentioned above.

That is, the present invention provides a developer containing a cassette toner that can simplify the manufacturing process.

Further, the present invention provides a developer containing a pressure-fixable capsule toner having stable developability and durability.

Furthermore, even when the present invention is made into a magnetic toner for a one-component developer containing all magnetic fine particles, the pressure fixing component has good pressure fixing properties, exhibits good magnetism, and can be electrostatically transferred. The present invention provides a full range of developers including encapsulated toners.

That is, the present invention consists of a first layer outer shell that uniformly covers the entire core material, and a second layer outer shell that further covers the whole or a part of the outer layer. The capsule toner is a multi-layered capsule toner deposited by pH adjustment without the use of essentially any dissolving solvent.

That is, in the present invention, as the first layer outer shell which uniformly covers the entire core material, the second layer outer shell is precipitated by using a solvent sound that does not completely dissolve the first layer outer shell. Another feature is that the entire second outer shell layer can be easily deposited without dissolving the core material.

Next, I will explain these phenomena in more detail.

Since the present invention is a pressure-fixable capsule toner, a core material having pressure-fixable properties such as wax, wax, or a low molecular weight substance is usually used.

The second outer shell, which should be called the first outer shell, is usually made of many resins or high molecular weight polymers. Since these two substances are soluble in many solvents, it is possible to simply support the entire surface of the core material with the outer shell resin. Therefore, the core material/outer shell, both Therefore, it becomes necessary to form an unfavorable film (referred to as a first layer outer shell in the present invention).

That is, there are many restrictions in order to completely deposit the first layer of the outer shell.

■ It is necessary to use a solvent that does not completely dissolve the core material and the second layer outer shell; 2. The adhesiveness of the core material and the second layer outer shell must be strong.

Therefore, in order to fully precipitate the first layer of the outer shell and to satisfy this requirement, an aqueous solution or a solvent that does not completely dissolve the core substance is required, and the inventors of the present invention have conducted extensive research and found that this can be achieved by adjusting the pH. In order to cause precipitation by pH adjustment, a film can be obtained by adding the entire polymer dissolved in an alkali or the entire polymer dissolved in an acid, respectively, to an acid or an alkali.

Further, since this first layer outer shell usually has a thickness of 0.05 to 0.3 .mu.m, the pressure fixing properties are the same even when compared with the stronger ones.

Usually, the core material contains all pressure fixing components.

Here, the material used as the pressure fixing component contained in the core material is preferably one that easily entangles with the fibers of plain paper under a linear pressure of about 20 kg/cm, and includes the following materials. Polyolefins such as polyethylene, polyzolopyrene, and polytetrafluoroethylene; System resin: Higher fatty acids such as palmitic acid, stearic acid, lauric acid: Polyvinylpyridone, epoxy resin, phenol-delhene copolymer, s? ') Methyl silicone, maleic acid-modified phenol resin, methyl vinyl needle-maleic anhydride copolymer, etc. Z) Polyethylene is the best in terms of fixability, mold releasability, developability, etc.

In the present invention, the first outer shell layer material includes casein,
Gelatin-phthalic anhydride branched reaction product, gelatin-trimellitic acid reaction product, gelatin-benzenesulfonyl chloride reaction product, vinegar peak London acid copolymer, biacetic acid-maleic acid copolymer, acetic acid bi-7-lyric acid Copolymer, J methylvinylpyridine-T methyl acrylate-methacrylic acid copolymer, styrene-vinylpyridine copolymer, methacrylic acid-
Methyl methacrylate copolymers, other polymers such as acrylic acid polymers, methacrylic acid polymers, crotonic acid, maleic acid, itaconic acid, citraconic acid, and vinylbenzoic acid, monomers with monomers containing monomers such as tetrathiol or vinyl monomers and acid groups. Copolymers of , cellulose derivatives such as phthalic acid, succinic acid, and maleic acid derivatives of starch, phthalic acid derivatives of cellulose, polyvinylpyridine, polyvinylimidazole, polygenylumine, and polyvinylaniline are used.

Examples of the second layer outer shell resin of the present invention include Ha? Purified polymers of styrene and its substituted products such as listyrene, P-chlorsnarene, boribi, and lutoluene, styrene-P-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinyl Naphthalene copolymer, styrene/methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, methyl methacrylate-octyl acrylate copolymer, styrene-methyl methacrylate copolymer , styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate co-W polymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-ingrene copolymer, sterene-acrylonidyl-dene copolymer, methyl-1-maleic acid copolymer, Sburen-maleic acid ester co-conjugate, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, for polynibs, polyzolopyrene, polyester, polyurethane, polyamide, Epoxy resins, polyvinyl butyral, polyvinyl butyral, polyamide resins, rosins, modified resins, terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, salts, etc. Alternatively, they can be used in combination.

Is there a charge control agent such as nigrosine, a metal-containing dye conventionally used in toners, in the outer shell resin? An appropriate amount may be added.

Furthermore, it can also be used by mixing (external addition) with charge control agent fine particles' (r1.ner).

In the cassette toner of the present invention, all dyes, pigments, etc. conventionally used as coloring agents for toners can be used as required, and they may be added to one or both of the core material and the outer shell.

Furthermore, if it is desired to obtain a magnetic toner, magnetic fine particles may be added to the toner. As a magnetic substance (cough magnetic), any material that can be magnetized may be used, such as evaporative iron, manganese,
Materials conventionally known as magnetic paulownia materials can be used, such as fine metal powders such as nickel, cobalt, and chromium, various ferrites, alloys and compounds such as manganese, and other ferromagnetic alloys. The magnetic fine particles of Koit et al. may be added to either the core material or the shell material.

The image obtained with the toner of the present invention is fixed by passing it between a pair of pressure-loaded rollers, but supplementary heating may also be performed.

Regarding pressure fixing devices, Japanese Patent Publication No. 44-12'797, U.S. Pat. No. 3,269,626, U.S. Pat. No. 3,612,
No. 682, No. 3,655,282, No. 3,731
, No. 358, etc., and the force 2° cell donor of the present invention can be used.

Examples are shown below. The number of copies is the number of vehicles.

Example 1 Hiwax 320P (Mikata Petrochemical Industry Co., Ltd. 1
00 parts Bolienalene wax EPT-1000 (Madai Tite manufactured by Toda Kogyo) 60
After uniformly dispersing 100 g'k of 5-20 μm core material consisting of
The whole mixed solution was added dropwise to precipitate the sikazein, and the slurry was filtered, washed, and dried.

As a result, the first layer outer shell and casein were punched out uniformly at the corners of the core material.

Next, 100.9 pieces of this dry fine powder, 5 g of styrene-methylamine ethyl methacrylate l/-l-4 pieces, DM
After uniformly dispersing F 3 Q Q ml of the resin solution, the entire resin solution is added dropwise (20,100 ml) to completely precipitate the resin, and this slurry solution is filtered, washed, and dried to remove the first layer. A toner was obtained in which a second outer shell layer was formed on the shell.
l-No. Next obtained Tonake Canon copier PC
-10 fixing total linear pressure 10 kg/oy+ rigid body 1j
-- When I printed out an image using a different color, a clear copy of the image was obtained.

Next, we will show the results of the durability test.

Example 2 - 5-2 consisting of 80 parts of rough-in wax (having a melting point of 155°F 2), 20 parts of carnauba wax, and 60 parts of magnetite.
After uniformly dispersing the 0 μm core material 'k100gi,
NH4OH5Q ml was added dropwise to completely precipitate polyvinylpyridine, and this slurry was completely filtered, washed, and dried. As a result, the surface of the core material was uniformly coated with polyvinylpyridine as the first outer shell.

Thereafter, the same treatment as in Example 1 was carried out to completely cover the second layer of the outer shell, and the same good results as in Example 1 were obtained.

Example 3 100 g of the core material of Example 2 was added to acrylic acid polymer water.
After uniformly dispersing 200mJ, NH4OH20m
The acrylic acid polymer was precipitated using a droplet filter, and the slurry was purified by light and dried. As a result, the acrylic acid polymer is uniformly coated on the surface of the core material as a first layer outer shell.
,Ta. Thereafter, the same treatment as in Example 1 was applied to cover the entire outer shell of the 21st vehicle, and the same good results as in Example 1 were obtained.

r-”-””-.

Agent: Akira Yama-・j (-・) "--] )　　　・j υ “Part 1-Self・

Claims (1)

[Claims] It consists of a first layer outer shell that uniformly covers the entire core material and a second layer outer shell that further covers the whole or a part of the outside, and the first layer outer shell is a solvent that dissolves the second layer outer shell. A developer for developing an electrical latent image with a % gold characteristic consisting of a layer deposited by P11 adjustment without the use of any substance.