JPS6325664A - Preparation of toner - Google Patents

Abstract

PURPOSE:To form spherical toner particles and to obtain the toner superior in fluidity and triboelectrification characteristics by dissolving or dispersing toner components into a volatile solvent of <=100 deg.C boiling point, mixing this solution or dispersion with water containing a dispersion stabilizer, stirring the mixture to emulsify it, and removing the volatile solvent. CONSTITUTION:The toner components are dissolved or dispersed into the volatile solvent of <=100 deg.C boiling point, this obtained solution or dispersion is mixed with the water containing the dispersion stabilizer, the mixture is stirred and emulsified, and the volatile solvent is removed from this emulsion to obtain spherical toner particles. The toner is composed of a toner resin, a wax, an electrification controller, a dye of pigment, a magnetic powder, and other additives. The one-component type toner comprises 40-70pts.wt. of the resin, 1-5pts.wt. of the wax, 1-5pts.wt. of the electrification controller, 0-3pts.wt. of the pigment, and 30-60pts.wt. of the magnetic powder, and the like, and the binary-component type toner is composed of 60-95pts.wt. of the resin, 1-5pts.wt. of the wax, 0.1-5pts.wt. of the electrification controller, 2-6pts.wt. of the pigment, 0-30pts.wt. of the magnetic powder, and the like.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an electrophotographic process in which dyes, pigments, magnetic powder, charge control agents, etc. are blended into a toner resin such as a resin or wax. The present invention relates to a method of manufacturing a toner for use in a computer.

(Prior art) The general method for producing toner for electronic photography is to disperse dyes, pigments, magnetic powders, etc. in toner resin by melting and kneading, and then mechanically crushing and classifying the powder. It is.

However, it has been pointed out that the toner obtained by this method has drawbacks such as being amorphous, making it difficult to obtain a uniform charge, and having poor fluidity.

Furthermore, the consumption of electrical energy required for melting, kneading, and pulverization is enormous, and various methods of producing toner using methods other than the so-called pulverization method have been proposed.

As methods other than the above-mentioned pulverization method, spray drying method, emulsion polymerization method, interfacial polymerization method, suspension polymerization method, etc. are known.

However, the spray drying method requires explosion-proof measures and solvent recovery; in the emulsion polymerization method, the particle size is too small for a toner; 1. it is difficult to mix coloring components; The suspension m@ method and the like do not necessarily seem to be superior to the pulverization method for reasons such as restrictions on the resins that can be used as toner components.

However, it is also important to improve the fluidity of the toner. Spheroidizing the toner for the purpose of equalizing the charge, etc.
Two different manufacturing methods are being studied with the aim of saving electrical energy through the pulverization method.

(Problems to be Solved by the Invention) An object of the present invention is to obtain a toner having excellent fluidity and triboelectric charging properties by spheroidizing the shape of the obtained particles.

[Structure of the invention]

(Means for Solving the Problems) The present invention involves mixing and stirring a liquid obtained by dissolving and dispersing toner components for electrophotography in a volatile solvent having a boiling point of 100°C or less with water containing two dispersion stabilizers. Emulsify.

By removing the j1-generating solvent from the emulsion.

This is a method for producing substantially spherical toner.

In the present invention, toner components for electrophotography include 2 toner resins, waxes, charge control agents, dyes, pigments, sex powders, and other additives, which are applicable to both -component and two-component toners. sell.

In the present invention, the toner resin includes polystyrene,
Styrene-containing copolymers of styrene and acrylic esters, methacrylic esters, acrylonitrile, maleic esters, etc., polyacrylic ester systems, polymethacrylic ester systems.

Polyester-based, polyamide-based, polyvinyl acetate-based.

Examples include epoxy resins, phenol resins, hydrocarbon resins, petroleum resins, etc., and these can be used alone or in combination.

Can be used in combination.

These resins are those that have good solubility in a solvent having a boiling point of 100° C. or lower, which will be described later.

The wax is used to improve the offset resistance of the toner, and examples thereof include polyethylene wax, polypropylene wax, microcrystalline wax, paraffin wax 7 oxide wax, 3 vegetable waxes, animal waxes, mineral waxes, etc. They can be used alone or in combination as required.

These waxes do not necessarily dissolve in a solvent having a boiling point of 100'C or lower, which will be described later, and can be used in a swollen or dispersed state.

The charge control agents are Subiron Buranok, Oil Black, Fetschwarz-HBN, Nigrosine Base, Brilliant Spirit, and Pomelo Schwarz-X.

Dyes such as Ceres Schwarz RG, copper phthalocyanine dyes, metal-containing dyes, C,1, Solvent Black 1,2°3.5,7. C, 1, acid blank 123, 22° 23.28.42, 43. Quaternary ammonium salt.

Naphthenic acid metal salts, fatty acids or resin acids, colloidal silica, and the like can be used.

Colorants include zinc yellow, yellow iron oxide, Hansa yellow, disazo yellow, quinoline yellow, permanent yellow, permanent red, red iron oxide, litho red, and wochanresodo Ca salt.

Watchan Resodo Mn[, Pyrazolone Left, Lake Red C, Lake Red D, Brilliant Carmine 6B
Pigments or oil-soluble dyes such as , Prilliant Carmine 3B, navy blue, phthalocyanine blue, metal-free phthalocyanine, titanium oxide, and carbon black can be used.

As the magnetic powder, alloys or compounds of iron such as various ferrites, magnetite and hematite, zinc, cobalt, nickel, manganese, etc. can be used.

These magnetic powders preferably have a bispherical or cubic octahedral shape with an average particle diameter of 0.1 to 0.5 microns, and are surface-treated to ensure good dispersion in the resin solution. The material may be subjected to hydrophobic treatment, silane coupling agent treatment, resin coating treatment, or the like.

The solvent for dissolving and dispersing the electrophotographic toner components is for evaporating and removing the solvent from water.

Use a solvent with a boiling point of 100°C or less. Also, if the solvent is easily miscible with water, resin precipitation will occur instantly.

Use a material with low miscibility with water.

Such solvents include dichloromethane, trichloromethane, tetrachloromethane, dichloroethane, 1. C
Halogenated hydrocarbon solvents of L-trichloroethane, trichloroethylene, and ethyl ether.

Ether solvent of isopropyl ether, hexane.

Hydrocarbon solvents such as benzene can be used.

In the present invention, the toner components for electrophotography include - component type toner: 40 to 70 parts by weight of resin, 1 to 5 parts by weight of wax, 0.1 to 5 parts by weight of charge control agent, and 0 to 3 parts by weight of pigment. parts, 30 to 60 parts by weight of magnetic powder, etc.

Further, as a two-component toner, 60 to 95 parts by weight of resin, 1 to 5 parts by weight of wax, 0.1 to 5 parts by weight of charge control agent, 2 to 6 parts by weight of pigment, 0 to 30 parts by weight of magnetic powder, etc. The components are dissolved and dispersed in the solvent having a boiling point of 100°C or less.

Although dissolution and dispersion vary slightly depending on the type of solvent and resin, the /8 agent is used in an amount of 30 to 90 parts by weight per 10 to 70 parts by weight of electrophotographic toner components, and the toner components are mixed in a ball mill, Atlighter.

A method of dispersing with a dyno mill or the like, or a method of dissolving the resin etc. in advance with a solvent and then adding the remaining components and dispersing the resin, etc., are used.

The above-mentioned dissolved dispersion of toner components is mixed and stirred with water containing a dispersion stabilizer.

Dispersion stabilizers include polyvinyl alcohol, polyvinylpyrrolidone, and hydroxyethyl cellulose.

These include cellulose gum, fine silica powder, water-soluble polymer compounds such as sodium lauryl sulfate and sodium oleate, gold mud oxide, and surfactants.

These dispersion stabilizers have the effect of making each particle smaller and making the particle size more uniform.

Mixing and stirring can be carried out by adding a dissolved dispersion of toner components to water containing a dispersion stabilizer, or vice versa, by adding water containing a dispersion stabilizer to a dissolved dispersion.

Mixing and stirring can be performed using a high-speed stirrer, an ultrasonic disperser, or the like.

High-speed stirrers include homomixers, homogenizers,
Homodisper etc. can be used and stirred at several thousand revolutions or more.

In the present invention, the solvent with a boiling point of 100°C or less evaporates from the emulsion even at room temperature during mixing operations such as high-speed stirring.
Although the toner components are precipitated in the form of fine particles, it is also effective to carry out the process without heating or under reduced pressure in order to promote volatilization of the solvent.

After confirming that the solvent has evaporated, wash and centrifuge.

By performing operations such as drying, spherical atomized toner can be obtained.

If necessary, the toner surface is subjected to hydrophobizing treatment, classification, and mixing with a fluidity improver such as silica.

The present invention will be explained below with reference to Examples.

Example 1 A dispersion of toner components was prepared according to the following formulation.

Styrene-n-butyl acrylate copolymer (85:1
5) 52.5 m 9 parts Polyethylene wax 3.0 parts (1 part carbon black 1.5 parts by weight Charge control agent (Bontron N-01 manufactured by Orient Kagaku@) 2.
0 parts by weight Magnetic powder EPT-500 (manufactured by Toda Kogyo) 37.5 parts dichloromethane 232.5 parts by weight Dispersion was carried out in a ball mill for 15 hours to obtain a gravure ink-like dispersion.

75 parts by weight of the above dispersion was added to 500 parts by weight of a 1% polyvinyl alcohol solution, and an ultra homomixer (OH-
Type 1 Nihon Takuoki n! Ii! Emulsification and dispersion was continued at 110,000 rpm.

Stop stirring when the dichloromethane odor disappears.

After repeating washing and decantation several times, it was dried with a spray dryer and classified to eliminate particles of 25 μm or more to obtain a fine spherical toner.

Example 2 755 parts by weight of the gravure ink-like dispersion obtained in Example 1 and 2 parts by weight of Aerosil A-200 (manufactured by Nippon Aerosil ■) were added to a solution in which 500 parts by weight of purified water was dispersed. Fine spheroidized toner was obtained in the same manner.

Also, 2 weights of sodium dodecylbenzenesulfonate was dissolved in 500 parts by weight of purified water.

A fine spheroidized toner was obtained in the same manner as in Example 1.

Example 3 In Example 1, at the same time as the emulsification and dispersion was started, the mixture was gradually heated and continued until the liquid temperature reached 50° C., and stirring was continued until the solvent odor of dichloromethane disappeared.

Thereafter, the same operations as in Example 1 were repeated five times to obtain toner particles in the form of minute spheres.

When 100 parts by weight of the above toner was dry mixed with 0.3 parts by weight of positively charged silica and printed on a commercially available copying machine (NP-150Z manufactured by Canon@), good images without fog were obtained. I was able to get it.

〔Effect of the invention〕

The present invention can save electrical energy required for kneading, pulverization, etc., and can obtain microspheroidal toner by using a low boiling point solvent that is easy to recover.

Claims (1)

[Claims] 1. A liquid obtained by dissolving and dispersing electrophotographic toner components in a volatile solvent with a boiling point of 100°C or less is mixed with water containing a dispersion stabilizer and stirred to emulsify it, and the volatile solvent is removed from the emulsion. A method of producing substantially spherical toner by removing.