JPS5978368A - Production of toner - Google Patents

Abstract

PURPOSE:To obtain a spherical toner which provides an excellent image and has high coloring power by polymerizing a monomer dissolved or dispresed therein with a dye and pigment with the particles formed beforehand by polymn. thereby growing the particles. CONSTITUTION:A polymerizable monomer such as ethylene, propylene or the like and 0.3-0.8wt% polymn. initiator such as H2O2 basing on the monomer are emulsified in water dispersed therein with a surfactant such as potassium palmitate at the critical micelle concn. or below whereby a seed particle is formed. A soln. prepd. by dispersing a coloring agent selected from a pigment and dye which does not retard considerably polymn. at 5-50wt% basing on the total toner in 1-10wt% concn. of a water soluble high polymer such as methyl cellulose or the like is added to such particle to polymerize further the monomer around the seed particle at 2-3pH and 30-100 deg.C thereby growing the grain size 3-100 times. Such particles are dried to prepare a toner. The monomer used in the polymn. for the 1st stage and the monomer for the 2nd stage may be the same of different.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing toner used in electrostatic photography and the like.

Toner for electrostatic photography can be developed using conventionally known development methods, such as a two-component development method such as a cascade development method using a mixture with a carrier or a magnetic brush development method, or a two-component development method such as a magnetic brush development method in which the toner is mixed with a carrier. A one-component developing method in which the latent image is conveyed using It is.

Conventionally, toner for electrostatic photography has been produced using the so-called pulverization method, in which a colorant, a charge control agent, a fluidity improver, a grinding aid, a mold release agent, etc. are added to a thermoplastic resin, kneaded, and then pulverized and classified. There is. As other toner manufacturing methods, a suspension polymerization method is proposed in JP-A-53-17735, and an emulsion polymerization method is proposed in JP-A-52-108134. These toners are obtained directly by suspending or emulsifying polymerizable monomers, polymerization initiators, colorants, and other components in water. However, due to the natural laws of ``pulverization'' itself, the former pulverization method results in a wide particle size distribution and irregularly shaped particles.
In order to obtain toner having a uniform particle size, the classification yield becomes significantly poor. In the latter case, even if a spherical product is obtained, suspension polymerization requires a large amount of dispersant such as a water-soluble polymer substance or a poorly soluble inorganic substance, and acid treatment or water washing is necessary to remove this. Even if this is done, a small amount will remain on the toner surface, and the moisture (humidity) in the air will affect the electrical conductivity of the toner, making the triboelectric charging characteristics of the l-toner unstable. Furthermore, even if a particle size distribution that poses no practical problems can be achieved, it is still not sufficient.

Furthermore, when considering future copying machines including office automation, color copying must be considered.

It is the trend of the future that more and more visual expressions will become available, and colorization is an essential condition, so it is important to have excellent images, that is, coloring power.

It is necessary to obtain toner particles with excellent color, gradation reproducibility, and fine line reproducibility, that is, toner particles with a very narrow particle size distribution, spherical shape, and a high coloring power of around 10.

Therefore, the present invention provides a new method for producing electrophotographic toner that is in line with the trends of the times. 6. The purpose of the present invention is to:
An object of the present invention is to provide a method for producing toner having a narrow particle size distribution.

Furthermore, it is an object of the present invention to provide an electrostatic photographic I that has uniform triboelectric charging.
・Provides a method for producing ner.

Furthermore, the present invention provides an electrostatic photographic toner having strong coloring power.

The feature is that the monomer in which the facial cleanser is dissolved or dispersed is polymerized into particles that have been prepared in advance by polymerization from monomers in which the facial cleanser is dissolved or dispersed as necessary, and the particles are adjusted to a particle size. The present invention provides a method for producing a toner that grows 3 to 100 times (more preferably 4 to 50 times).

This method of preparation is an application to toners of a method commonly known as sheet polymerization. The mechanism of this method will now be explained in detail.

The particles that become the seeds of sheet nail alignment are wa variation! Ilj must be very sharp. This is because Jidopa and, by extension, ij grow just as they are.

That is, in order to obtain a toner with a sharp particle variation/1j by seed polymerization, the seed particles must have a very sharp particle size distribution. Therefore, in this case, seed rice is prepared by the emulsion polymerization method, which is known to provide a sharp particle size distribution, or by the so-called reprecipitation method. This may be done by a generally known method; for example, in the case of emulsion polymerization, monomers containing additives are mechanically or electrically emulsified in water in which a surfactant is dispersed, and 1,000 polymers are polymerized. Just do it. The initiator for polymerizing the monomers may be added to the monomers from the beginning, or may be added later when the monomers are in an emulsified state. The particles produced by this method have a very sharp particle size distribution, but since only particles with a particle size of 1jL or less can be produced, they are too small to be used as a toner as is. Therefore, seed polymerization is performed using these fine particles as seeds. That is, if we look at polymerization, the first stage of polymerization is emulsion polymerization to create seed particles, and the second stage of polymerization is the seed polymerization that is performed next.

There are generally two types of seed polymerization: That is, there are cases where the same monomer as the seed particles is used in the second stage, and cases where a different type of monomer from the first stage is used in the second stage. When 1,000 polymers for the second stage of polymerization are added to the emulsion containing the seed particles, the added monomers selectively gather around the seed particles and interact with the water outside. Surfactant collects at the interface. Therefore, particles do not aggregate together. At this point, you may add a surfactant if necessary. The monomers that collect on the sides of the seed rice swell the seed particles and cause them to grow.

At this time, it is good to use a melt to help swelling. At this point, if the face wash is completely dissolved or dispersed, the face wash will enter the interior along with the seed particles.

Thereafter, a second stage of polymerization is carried out. At this time, the solvent added to aid swelling is removed. The initiator for polymerization was added during the first stage polymerization, and B
The reaction may be carried out starting from 1, or it may be added from the outside. After the polymerization is complete, this is dried and prepared as 1.

Examples of the polymerizable monomer used in the present invention include the following unsaturated compounds. Ethylene, propylene, l-butene, 2-butene, imbutylene, 1-pentene, 2-
Methyl-2-butene, ■-hexene, 4-methyl-1-
Pente〉', 3,3-dimethyl-1-butene, 2,4.
4-l dimethyl-l-pentene, 6-ethyl 1-hexene, ■-heptene, 1-octene, styrene, α-
Chlorostyrene, α-methylstyrene, allylbenzene, phenylacetylene, vinylnaphthalene, 4-methylstyrene, 2,4-dimethylstyrene, 3-ethylstyrene, 2,4-diethylstyrene, 2-methoxystyrene, 4-chlorostyrene , 4-fluorostyrene, 3-
Iodostyrene, 4-cyanostyrene, 3-nitrostyrene, 2-aminostyrene, acrylic acid, methacrylic acid, acrolein, methacrolein, acrylonitrile, acrylamide, methacrylamide, methyl acrylate, methyl acrylate, ethyl acrylate, butyl meccrylate, N,N-dimethylacrylamide, vinyl chloride, vinylidene chloride, vinylidene fluoride, trichloroethylene, vinyl acetate, vinyl propionate,
Vinyl butyrate, vinyl benzoate, vinyl formate, vinyl oleate, vinyl adipate, maleic anhydride, dimethyl fumarate, diethylstyrene I., cyamyl fumarate, etc.

As the catalyst, surfactant, buffer, and other components used in the present invention, those used in well-known emulsion polymerization can be used.

Typical free radical initiators and redox catalysts are used as the polymerization initiator. For example, free radical initiators include hydrogen peroxide, peracetic acid, t-butyl hydroperoxide, di-tert-butyl peroxide, dipensoyl peroxide, perbenzoic acid, tertiary-notyl peracetate, azobisisobutyroperoxide, nitrile,
Ammonium persulfate, sulfur/lium persulfate, potassium persulfate, potassium superphosphate, etc. As a Retonx solvent system,
Sodium persulfate-formaldehyde sulfoxylate 1
・Storium, cumene hydroperoxide-sodium metabisulfite, hydrogen peroxide-ascorbic acid, etc.

Only the most effective concentration of lrf agent is used in general emulsion polymerization. Generally Q for 1,000 tsuma, 3~0.8w
It is in the range of t%.

In the present invention, surfactants commonly used in emulsion polymerization can be used. For example, anionic activators include potassium palmitate, potassium stearate, potassium caprate, potassium oleate, sodium dodecylsulfonate, sodium laurate, sodium rosinate, alkyl sodium sulfosuccinate, and cationic activators. There are long-chain quaternary amines, etc., and nonionic activators include ethylene oxide condensates of lysyllic acid, lauric acid, lysyllic acid, and caproic acid,
Examples include ethylene oxide condensates of oleic alcohol, cetyl alcohol, and lauryl alcohol, and integrated products of octylphenol, nonylphenol, and ethylene oxide.

The above surfactants can be used individually or in combination.

Generally, the concentration of surfactant is preferably less than the critical micelle concentration (CMC), but it may be added at a concentration higher than the critical micelle concentration (CMC) for the purpose of increasing the emulsion particle size or stabilizing the particles. However, in this case, NH45 (N (ammonium thiocyanide)
It is necessary to prevent emulsion polymerization in the aqueous phase by using polymerization inhibitors such as copper salts or copper salts to suppress the generation of new particles.

Examples of the water-soluble polymer in which the colorant is dispersed include cellulose ethers such as methylcellulose, ethylcellulose, benzylcellulose, carboxymethylcellulose, carboxyethylcellulose, aminoethylcellulose, and oxyethylcellulose, natural polymers such as gelatin and starch, and polyvinyl alcohol. . In general, the following 1-
The water-soluble polymer has a concentration of 1 to IO wt%, preferably 3
~7% by weight is used.

The coloring agent is selected from normal phase dyes and dyes that do not significantly inhibit polymerization. The additive content is preferably 5 to 50% by weight based on the total toner.

Furthermore, appropriate amounts of a charge control agent, a fluidity improver, and a mold release agent may be added.

The pH during polymerization is not particularly limited, but is usually in the range of 2 to 3. Further, the polymerization temperature is not particularly limited as long as it is within a range where normal emulsion polymerization can be carried out, but a range of 30 to 1 OO'C is suitable.

[Example 1] Polymerization reactor equipped with an IW stirrer, temperature control, monomer dropping funnel, and reflux condenser, 1 s o 6 of ion-exchanged water inside
B, 1 part of Emulken 920 (manufactured by Kao Atlas Co., Ltd.; nonionic surfactant) and 4 parts of BPOo were charged, and 20 parts of styrene monomer and 50 parts of a 5% aqueous solution of B-17 (polyvinyl alcohol, manufactured by Denki Kagaku Co., Ltd.) were added thereto. At the same time, a seed latex was produced. The reaction was carried out for 3 hours at a polymerization temperature of 70°C.

- Add 05 parts of Tenx and 0.5 parts of Emulken to 160 parts of ion-exchanged water, add 20 parts of styrene monomer and 2 parts of Lionol Sol KL (manufactured by Toyo Ink Co., Ltd.).
A composite polymer latex having a particle size of 9 to 12 was prepared by adding 1,000 ml of 1,000 ml of dissolved 1,000 ml of 1,000 ml, and a toner was obtained by spray-drying this latex.

This toner was spherical, had a number average particle diameter of io, 5#, and a weight average of 12.4 g as measured by a Coulter counter, and had a blue color. To this toner, 0.5 ut% colloidal silica R972 (manufactured by Nippon Aerosil Co., Ltd.) was externally added, and the carrier ° iron powder and 10 wt % toner Contin I were combined with 4'/self, and imaged using NP-5500. As a result, a high-density blue image of good quality was obtained.

[Example 2] After producing styrene seed latex in the same manner as in Example-1, 0.5 parts of this seed latex and Emulgen 920.0 were added.
．． Add 5 parts to 160 parts of ion-exchanged water, add thereto a monomer prepared by dissolving 2 parts of Furnal Pink in 20 parts of ethyl acrylate to prepare a polymer latex, and then spray dry this latex!・I got a na. Number of pieces: 11, average particle size: 98 parts, 1 piece, M-'li, average particle size: 11.
It was Op (according to the call counter).

This toner contains 0.5wt% colloidal silica R97.
2 (manufactured by IE Hon Aerosil Co., Ltd.) and mixed with carrier iron powder and 10 wt% toner content sea urchin, NP-55.
As a result of image extraction using 00, a high-density, pink, high-quality image was obtained.

Claims (1)

[Claims] A method for producing a toner, in which particles prepared in advance by polymerization are polymerized with a monomer in which a facial cleanser is dissolved or dispersed, and the particles grow 3 to 100 times larger in particle size.