KR101156609B1 - Method of producing polymerized toner - Google Patents

Abstract

The present invention relates to a polymerized toner and a method for producing the polymerized toner, and to a polymerized toner comprising polyvinyl difluoride particles having an average particle diameter of 1.1 to 1.5 탆 and a Tm of 140 to 160 캜 in a polymerized toner core. The present invention relates to a polymerized toner having excellent transfer efficiency.

Description

Polymerized toner manufacturing method {METHOD OF PRODUCING POLYMERIZED TONER}

The present invention relates to a polymerized toner and a method for producing the polymerized toner, and more particularly, to a method for producing a polymerized toner including polyvinyl difluoride particles in a polymerized toner core to improve transfer efficiency.

Toner is used in electrophotographic development, electrostatic printers, copiers, and the like, and refers to a paint that can be transferred to and fixed on a transfer object to form a desired pattern. Recently, as document creation using a computer is generalized, demand for an image forming apparatus such as a printer is rapidly increasing, and thus, the amount of toner is also increasing.

As a method of manufacturing the toner, there are a manufacturing method using pulverization and a manufacturing method using polymerization. The most widely known method of pulverization is a melt-mixing process in which resin and pigment are put together, melt-mixed or extruded, pulverized and classified to produce toner particles. However, the toner particles produced by this process have a problem of poor chargeability or flowability because the toner particles have a very irregular shape such as wide particle size distribution and pointed edges.

In order to solve this problem, a method of producing spherical toner particles by a polymerization method has been proposed. The polymerization method of the toner by the polymerization method is known as emulsion polymerization / aggregation method and suspension polymerization method. Since the emulsion polymerization method is difficult to control the size distribution of particles and there is a problem in the reproducibility of the produced toner, suspension polymerization The method by is preferred.

Toner is transferred from the drum to the paper during printing, and the toner remaining in the drum without being transferred to the paper remains in the drum portion. At this time, in order to realize the best image density with respect to the amount of toner consumed without causing background contamination on the image, it is necessary to transfer as much of the toner as selectively moved from the supply unit to the drum as much as possible. Increasing the efficiency (transfer efficiency) at which toner is transferred to paper is an important problem in toner.

The present invention is to solve the above problems, transfer by increasing the amount of charge on the surface of the toner by including polyvinyl difluoride particles having an average particle diameter of 1.1 ~ 1.5㎛ and Tm 140 ~ 160 ℃ in the polymerized toner core It is an object of the present invention to provide a polymerized toner having improved efficiency and a method for producing the same.

The present invention is to achieve the above object, it provides a polymerized toner, characterized in that the polyvinyl difluoride (poly (vinyl difluoride)) particles are contained in the polymerized toner core.

In addition, the polyvinyl difluoride particles are characterized in that the average particle diameter is 1.1 ~ 1.5㎛.

In addition, the melting temperature of the polyvinyl difluoride particles is characterized in that 140 ~ 160 ℃.

In addition, the polymerization toner is prepared by polymerizing a monomer mixture, wherein the monomer mixture is characterized in that it comprises a polyvinyl difluoride, a binder resin, and a charge control agent.

The binder resin monomer may be an aromatic vinyl monomer, an acrylate monomer, a methacrylate monomer, a diene monomer, or a mixture thereof.

In addition, the binder resin monomer is characterized in that it further comprises an acidic olefin monomer or a basic olefin monomer.

In addition, the charge control agent is an acid dye of nigrosine type, high aliphatic metal salt, alkoxy amine, chelate, quaternary ammonium salt, alkylamide, fluorine treatment active agent, metal salt of naphthalene acid, acid organic complex, chlorinated paraffin, chlorinated polyester , A polyester containing an acid, sulfonylamine of copper phthalocyanine, a styrene-acrylic polymer containing a sulfonic acid group, or a mixture thereof.

In addition, the monomer mixture is characterized in that it further comprises at least one additive selected from the group consisting of a wax, a crosslinking agent, a molecular weight regulator and a reaction initiator.

In addition, the wax is characterized in that the paraffin wax, microcrystalline wax, ceresin wax, carnuba wax, ester wax, polyethylene wax, polypropylene wax or a mixture thereof.

In addition, the crosslinking agent is divinylbenzene, ethylene dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,6-hexamethylene diacrylate, allyl methacrylate, 1,1,1- Trimethylolpropane triacrylate, triallylamine, tetraallyloxyethane or a mixture thereof.

In addition, the molecular weight modifier is characterized in that t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, carbon tetrachloride, carbon tetrabromide or mixtures thereof.

In addition, 1 to 60 parts by weight of monomer for binder resin, 1 to 10 parts by weight of dispersion stabilizer, 0.1 to 30 parts by weight of wax, 0.001 to 10 parts by weight of crosslinking agent, 0.1 to 20 parts by weight of charge control agent, 0.001 to 8 parts by weight of molecular weight regulator, 0.01 to 5 parts by weight of the reaction initiator, and 1 to 5 parts by weight of polyvinyl difluoride.

In addition, the present invention comprises the steps of mixing the dispersion stabilizer with water to prepare an aqueous dispersion; Homogenizing the monomer mixture by dispersing a monomer mixture comprising polyvinyldifluoride, a monomer for a binder resin, and a charge control agent in the form of fine droplets in the aqueous dispersion; Polymerizing the homogenized monomer mixture to produce a polymerized core; Washing and drying the polymerized polymer toner core; And it provides a polymerized toner manufacturing method comprising the step of coating the polymerized toner core with the external additive.

In addition, the aqueous dispersion is characterized in that 1 to 10 parts by weight of the dispersion stabilizer is added to 100 parts by weight of water to make an aqueous dispersion.

In addition, the dispersion stabilizer is a water-soluble polyvinyl alcohol (PVA) having a degree of polymerization of 1,500 to 2,500, saponification of 75 to 98%.

According to the present invention, a polymerized toner having excellent transfer efficiency can be produced by a polymerized toner containing polyvinyl difluoride particles having an average particle diameter of 1.1 to 1.5 µm and a Tm of 140 to 160 ° C in the polymerized toner core.

The present invention is homogenized by mixing a monomer mixture in an aqueous dispersion in which a dispersion stabilizer is dispersed in water, and polymerizing the homogenized monomer mixture to form a polymerized toner core, washing and drying to prepare a polymerized toner core. Vinyl difluoride (poly (vinyl difluoride)) is characterized in that it contains particles.

The monomer mixture may include a monomer for a binder resin, a charge control agent, and the like.

Hereinafter, the present invention will be described in detail.

As the monomer for the binder resin, an aromatic vinyl monomer, an acrylate monomer, a methacrylate monomer, a diene monomer, or a mixture thereof may be used, and optionally an acidic or basic olefin monomer may be used. In addition, 0.01 to 10 parts by weight of one or more selected from polyester-based and styrene acrylic polar polymers may be added to the monomer mixture.

Styrene, monochlorostyrene, methyl styrene, dimethyl styrene, etc. can be used as an aromatic vinylic monomer, It is preferable to use these at 30-95 weight part with respect to monomer total.

As the acrylate monomer, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, and the like can be used. As the methacrylate monomer, methyl Methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, etc. can be used, and butadiene, isoprene, etc. Can be used.

It is preferable that at least one of the acrylate monomer, the methacrylate monomer and the diene monomer is used in an amount of 5 to 70 parts by weight based on the total monomers.

As the acidic olefinic monomer, an α, β-ethylenically unsaturated compound having a carboxyl group may be used, and as the basic olefinic monomer, methacrylic acid ester type, methacrylamide type, vinyl of an aliphatic alcohol having an amine group or a quaternary ammonium group An amine type, diallyl amine type, ammonium salt thereof, etc. can be used. When using one or more of the acidic or basic olefinic monomers, it is preferable to use 0.1 to 30 parts by weight based on the total monomers.

The dispersion stabilizer used in the present invention uses polyvinyl alcohol (PVA), and is dispersed in water to produce an aqueous dispersion.

The polyvinyl alcohol (PVA) has a degree of polymerization of 1,500 to 2,500 and preferably 1,700 to 2,100. The saponification degree of the water-soluble polychloride alcohol (PVA) is 75 to 98%, preferably 85 to 95%. When the degree of polymerization of polyvinyl alcohol (PVA) is less than 1,500, it is difficult to sufficiently disperse the monomer mixture in the aqueous dispersion, and when the degree of polymerization of polyvinyl alcohol (PVA) exceeds 2,500, the solubility of polyvinyl chloride (PVA) in water is Is lowered, making it difficult to form a uniform aqueous dispersion. If the saponification degree of polyvinyl chloride (PVA) is less than 75%, the solubility of polyvinyl alcohol (PVA) decreases when the temperature is raised to the reaction temperature (60 ° C, 90 ° C), so that the monomer mixture may be properly dispersed. If the degree of saponification exceeds 95%, the hydrophilicity of polyvinyl chloride (PVA) increases, and the performance as a dispersant decreases. The content of the dispersion stabilizer is 1 to 10 parts by weight based on 100 parts by weight of the aqueous dispersion. Add.

Examples of the charge control agent include cationic charge control agents, acidic organic complexes, and chlorinated paraffins such as nigrosin-type acid dyes, high aliphatic metal salts, alkoxy amines, chelates, quaternary ammonium salts, alkylamides, fluorinated activators, and metal salts of naphthalene acid. Anionic charge regulators or mixtures thereof, such as chlorinated polyesters, polyesters containing excess acid, sulfonylamines of copper phthalocyanine, styrene-acrylic polymers containing sulfonic acid groups, or mixtures thereof. It is preferable to use in an amount of 0.1 to 20 parts by weight with respect to.

To the monomer mixture, 1 to 5 parts by weight of polyvinyl difluoride particles having an average particle diameter of 1.1 to 1.5 μm and a Tm of 140 to 160 ° C. are added to 100 parts by weight of the total monomer mixture. When the polyvinyl difluoride particles are added to the core of the polymerized toner, the polyvinyl difluoride particles serve to increase the amount of charge of the polymerized toner by being located on the surface of the polymerized toner. If the average particle diameter of the polyvinyl difluoride particles is less than 1.1 mu m, it is not preferable because the amount of charge is not increased even if it is located on the surface of the toner, and if it exceeds 1.5 mu m, it is difficult to place the polyvinyl difluoride particles on the particle surface. Since the present invention is not preferable, the polyvinyl difluoride particles in the above range are used. In addition, when less than 1 part by weight of polyvinyl difluoride particles are not preferable because there is no effect of increasing the amount of charge, when it exceeds 5 parts by weight is not preferable because the stability during the polymerization reaction is lowered.

The present invention may further include at least one additive selected from the group consisting of wax, crosslinking agent, molecular weight regulator and reaction initiator in the monomer mixture.

As said wax, Petroleum refined wax, such as a paraffin wax, a microcrystal wax, a ceresin wax; Natural waxes such as carnuba wax; Or synthetic waxes such as ester waxes, polyethylene waxes, and polypropylene waxes. The wax is preferably used in 0.1 to 30 parts by weight based on the total monomers.

As the crosslinking agent, divinylbenzene, ethylene dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,6-hexamethylene diacrylate, allyl methacrylate, 1,1,1-trimethylol Propane triacrylate, triallylamine, tetraallyloxyethane, and the like are used and are preferably used in an amount of 0.001 to 10 parts by weight based on the monomer mixture.

As the molecular weight modifier, t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, carbon tetrachloride and carbon tetrabromide may be used, and these molecular weight modifiers may be used in the range of 0.001 to 8.000 for the monomer mixture. It is preferable to use by weight part.

The reaction initiator may further include 0.01 to 5 parts by weight based on the total monomers. As the reaction initiator, an oil-soluble initiator and a water-soluble initiator can be used. Specifically, Azo initiators, such as azobisisobutyronitrile and azobisvaleronitrile; Organic peroxides such as benzoyl peroxide and lauroyl peroxide; Generally used water-soluble initiators, such as potassium persulfate and ammonium persulfate, etc. can be used. The reaction initiator is preferably used in an amount of 0.01 to 5.00 parts by weight, more preferably 0.1 to 2.0 parts by weight, based on the monomer mixture.

As the external additive used in the present invention, silica particles are used.

Silica is used 1 to 5 parts by weight based on 100 parts by weight of the polymerized toner core.

After the addition of the silica, the external additive is coated on the surface of the polymerized toner core under high speed agitation.

The present invention also provides a method for producing the polymerized toner as follows.

Mixing the dispersion stabilizer with water to prepare an aqueous dispersion;

Homogenizing the monomer mixture by dispersing a monomer mixture comprising polyvinyldifluoride, a monomer for a binder resin, and a charge control agent in the form of fine droplets in the aqueous dispersion;

Polymerizing the homogenized monomer mixture to produce a polymerized core;

Washing and drying the polymerized polymer toner core; And

Coating the polymerized toner core with the external additive.

Hereinafter, a method of manufacturing the polymerized toner according to the present invention will be described in detail.

(1) Polymerized Toner Core Manufacturing Step

Dispersing water-soluble polyvinyl alcohol (PVA) as a dispersion stabilizer in an aqueous solution to prepare an aqueous dispersion, and adding a monomer mixture containing polyvinyl difluoride to the aqueous dispersion, applying a shear force to a homogenizer to homogenize and then polymerization. Proceed to produce the toner core.

As the monomer, an aromatic vinyl monomer, an acrylate monomer, a methacrylate monomer, a diene monomer, or a mixture thereof can be used, and optionally an acidic or basic olefin monomer can be used.

(2) polyvinyl alcohol (PVA) removal and drying step

In the solution containing the polymerized toner prepared above, polyvinyl alcohol (PVA) is first removed from the toner by a suitable method. After diluting the aqueous dispersion containing polyvinyl alcohol (PVA) containing the polymerized toner by adding distilled water twice the total weight, and applying shearing force with a homogenizer, the filter device, the filter press device, and the general centrifuge The water-soluble polyvinyl alcohol (PVA) can be separated from the toner through a separation and washing process using a separation device, a continuous deconverter type high speed centrifugal device, or the like. Finally, water is removed through filtering, the toner cake is put in a vacuum oven, and vacuum dried at room temperature to prepare a polymerized toner core.

(3) external additive coating step

After the silica was added to the polymerized toner core using a Henschel mixer, the external additive was coated on the polymerized toner core surface under high speed stirring for 7 minutes at a speed of 5000 rpm.

In order to describe the present invention in more detail, the following examples are described, but for the purpose of thorough understanding and disclosure of the present invention, the present invention is not limited thereto.

Example 1

(Production of Polymerized Toner)

After adding 5 parts by weight of a water-soluble polyvinyl alcohol (polymerization degree 1700, saponification degree 90%) as a dispersion stabilizer to 400 parts by weight of ion-exchanged water, the mixture was stirred for 10 minutes at room temperature, and then the temperature was raised to 70 ° C, which is a reaction temperature, and then 20 minutes. By stirring, an aqueous dispersion was prepared.

160 parts by weight of styrene, 36 parts by weight of n-butyl acrylate and 4 parts by weight of acrylic acid were used as monomers, 4 parts by weight of allyl methacrylate as a crosslinking agent, 0.4 parts by weight of n-dodecyl mercaptan as a molecular weight modifier, and a sulfonic acid group After fully dissolving 1 part by weight of the styrene-acrylic polymer charge control agent included, 10 parts by weight of the pigment was stirred at 2,000 rpm with a bead mill for 2 hours, and beads were removed to finally prepare 225 parts by weight of the monomer and pigment mixture.

The mixture was heated to 70 ° C. in a water bath, and then 5 parts by weight of paraffin wax and 3 parts by weight of polyvinyl difluid particles having an average particle diameter of 1.3 μm and a Tm of 150 ° C. were added, followed by stirring for 20 minutes. To prepare a polymerized toner, homogenized at a speed of 13000 rpm using an aqueous dispersion and a homogenizer to disperse the monomer mixture in the form of fine droplets in the aqueous dispersion, and then reacting for 15 hours while stirring at 200 rpm with a paddle type stirrer. .

(Cleaned by centrifuge)

Dilute distilled water twice the total weight to the aqueous dispersion containing the polymerized toner synthesized above, apply shear force with a homogenizer, and then use a centrifugal separator (Beckman J2-21M, Rotor JA-14). Centrifuge at 3,000 rpm for 15 minutes. After diluting the distilled water by adding 2 times distilled water to the concentrate containing the polymerized toner, applying shear force with a homogenizer and centrifuging at 3,000 rpm for 15 minutes using a centrifugal separator (Beckman J2-21M, Rotor JA-14). The separation process was repeated two more times to remove polyvinyl alcohol (PVA) from the toner surface. Finally, the water was removed through filtering, and the toner cake was put in a vacuum oven, and vacuum dried at room temperature for 48 hours to prepare a polymerized toner core. The volume average particle diameter of the prepared polymerized toner core is 7 microns and the ratio of the volume average particle diameter and the number average particle diameter is 1.26.

(External additive coating)

After adding 2 parts by weight of silica to 100 parts by weight of the polymerized toner core using a Henschel mixer, the external additive was coated on the surface of the polymerized toner core under high-speed stirring for 7 minutes at a speed of 5000 rpm.

[Example 2]

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the amount of the polyvinyl difluoride added was 4 parts by weight. The evaluation results are shown in Table 1.

Example 3

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the particle size of the polyvinyl difluoride was 1.5 μm. The evaluation results are shown in Table 1.

Example 4

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the Tm of the polyvinyl difluoride was 140 ° C. The evaluation results are shown in Table 1.

Comparative Example 1

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the polyvinyl difluoride particles were not added. The evaluation results are shown in Table 1.

Comparative Example 2

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the size of the polyvinyl difluoride particles was 2 µm. The evaluation results are shown in Table 1.

Comparative Example 3

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the amount of the polyvinyl difluoride particles added was 10 parts by weight. The evaluation results are shown in Table 1.

[Experimental Example]

(Charge amount of toner surface, Q / m)

Toner adhered to the sleeve roll in the cartridge was taken and Q / m was measured using a Q / m meter (Trek, model 210HS-2B).

(Transfer efficiency of toner)

Fill the surface-treated toner of the HP4600 printer (Hewlett-Packard) printer cartridge with the surface-treated toner, weigh the entire study, print 1,000 sheets of 19 cm by 1.5 cm rectangle on A4 paper, and then measure the weight of the supply again. Was calculated.

Consumption (g) = 1,000 sheets before printing Supply department  Weight-After 1,000 sheets print Supply department  weight

The weight of the drum portion that can be separated from the supply portion was measured before printing and after printing to calculate the amount of toner that was not transferred and wasted.

Waste amount of toner (g) = weight of drum after printing 1,000 sheets -weight of drum before printing 1,000 sheets

From the amount of toner consumed and wasted, the transfer efficiency was calculated by the following equation.

Transfer efficiency (%) = {(consumption-wasted Amount of toner ) / Consumption} * 100

The results are shown in Table 1.

Polyvinyl difluoride particle size (㎛) Polyvinyl difluoride addition amount with respect to 100 weight part of monomer mixtures (weight part) Tm of polyvinyldifluoride Charge amount of toner surface, Q / m (C / g) Transfer efficiency (%) Example 1 1.3 3 150 -14 98 2 1.3 4 150 -16 98 3 1.5 3 150 -13 98 4 1.3 3 140 -15 98 Comparative Example 1 - - - -12 95 2 2 3 150 -10 90 3 1.3 10 150 -15 80

Claims (3)

Mixing the dispersion stabilizer with water to prepare an aqueous dispersion;
Homogenizing the monomer mixture by dispersing a monomer mixture comprising polyvinyldifluoride, a monomer for a binder resin, and a charge control agent in the form of fine droplets in the aqueous dispersion;
Polymerizing the homogenized monomer mixture to produce a polymerized core;
Washing and drying the polymerized polymer toner core; And
Coating the polymerized toner core with an external additive;
Polymerized toner manufacturing method comprising a. The method of claim 1,
The aqueous dispersion is a polymerized toner producing method, characterized in that for adding 1 to 10 parts by weight of a dispersion stabilizer to 100 parts by weight of water to make an aqueous dispersion. The method of claim 1,
Wherein said dispersion stabilizer is a water-soluble polyvinyl alcohol (PVA) having a degree of polymerization of 1,500 to 2,500 and a degree of saponification of 75 to 98%.