KR101243708B1 - Polymerized Toner and Method of Producing the same - Google Patents

Abstract

The present invention relates to a polymerized toner and a method for producing the polymerized toner, wherein in the polymerized toner core and the polymerized toner coated with the core with an external additive, the external additive comprises a mixture of silica and polyester particles. The present invention relates to a manufacturing method, and according to the present invention, a polymerized toner having a uniform image and high transfer efficiency can be provided.

Polymerized Toner, External Additive, Silica, Polyester, Transfer Efficiency

Description

Polymerized Toner and Method of Producing Them {Polymerized Toner and Method of Producing the same}

The present invention relates to a polymerized toner and a method for preparing the polymerized toner, and more particularly, to a method of manufacturing a polymerized toner having a uniform image and high transfer efficiency by coating polyester fine particles with silica as an external additive to a polymerized toner core.

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 becoming more common, the 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 manufacturing using pulverization is to prepare toner particles by melting and mixing the resin and pigment together through melt-mixing process, pulverizing and extruding, pulverizing and classifying. 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 toner by the polymerization method is known as emulsion polymerization / aggregation method and suspension polymerization method. Since emulsion polymerization method is difficult to control the size distribution of particles and there is a problem in the reproducibility of the quality of the produced toner, Processes by polymerization are preferred.

The polymerized toner core formed by suspension polymerization is used by coating silica on the polymerized toner core with an external additive. At this time, when only silica is coated, there is a disadvantage that the image is uneven and the transfer efficiency does not reach the target level.

The present invention has been made to solve the above problems, and to provide a polymerized toner having a uniform image and high transfer efficiency by coating polyester particles with silica as an external additive to the polymerized toner core, and a method of manufacturing the same. It is done.

The present invention is to achieve the above object, in the polymerized toner coated with an external additive to the polymerized toner core, the external additive provides a polymerized toner, characterized in that the silica and polyester particles are used together.

In addition, the volume average particle diameter of the polyester particles is characterized in that 50 ~ 500nm.

In addition, the content of the polyester particles is characterized in that 0.1 to 2 parts by weight based on 100 parts by weight of the polymerized toner core.

The polymerized toner core may be prepared by polymerizing a monomer mixture including a binder resin monomer 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, 1 to 5 parts by weight of silica and 0.1 to 2 parts by weight of polyester, characterized in that it comprises.

In addition, the present invention comprises the steps of mixing the dispersion stabilizer with water to prepare an aqueous dispersion; Homogenizing the monomer mixture of claim 4 in the aqueous dispersion to disperse the monomer mixture in the form of fine droplets in the aqueous dispersion; Polymerizing the homogenized monomer mixture; 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 a uniform image and high transfer efficiency can be produced by a polymerized toner in which polyester particles are coated on a polymerized toner core together with silica as an external additive.

The present invention homogenizes the monomer mixture and the aqueous dispersion, polymerizes the homogenized monomer mixture to form a polymerized toner core, washes and drys to prepare a polymerized toner core, and then coats the polymerized toner core with an external additive to prepare a polymerized toner. In the production, it is characterized in that the silica and polyester particles are used together as the external additive.

The monomer mixture may be used by mixing a monomer for a binder resin, a charge control agent and the like.

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, methacrylic amide 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 polyvinyl 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 alcohol (PVA) in water is Is lowered, making it difficult to form a uniform aqueous dispersion. If the saponification degree of polyvinyl alcohol (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 98%, 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.

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

Silica is commonly used as an external additive of a polymerized toner, and 1 to 5 parts by weight based on 100 parts by weight of the polymerized toner core.

In addition, the present invention is characterized in that the use of polyester as an external additive in addition to the silica used as the external additive, when the polyester is used as the external additive has an excellent effect in that the image is uniform and the transfer efficiency is high. The polyester used in the present invention uses microparticles having a volume average particle diameter of 50 to 500 nm, but it is not preferable to use polyester particles of less than 50 nm because it is difficult to realize the advantage of uniform images. If it exceeds nm, the transfer efficiency is lowered, which is not preferable. The amount of the polyester particles used is 0.1 to 2 parts by weight, it is not preferable to add less than 0.1 parts by weight because it is difficult to implement the advantages of the addition of polyester particles, and exceeds 2 parts by weight is preferable because the transfer efficiency is lowered I can't.

After the above silica and polyester particles are added, an external additive is coated on the surface of the polymerized toner core under high speed agitation.

The present invention may further include one or more additives selected from the group consisting of waxes, crosslinking agents, molecular weight modifiers and reaction initiators in addition to the above components, and is referred to as a monomer mixture including the binder resin monomers and the additives.

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 an amount of 0.1 to 30 parts by weight based on the monomer mixture.

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 it is preferable to use 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.

The present invention comprises the steps of mixing the dispersion stabilizer with water to prepare an aqueous dispersion;

Homogenizing the monomer mixture by dispersing it in an aqueous dispersion;

Polymerizing the homogenized monomer mixture;

Washing and drying the polymerized polymer toner core; And

Characterized in that the polymerized toner manufacturing method comprising the step of coating the polymerized toner core with the external additive.

One embodiment of the present invention includes the following suspension polymerization step.

(1) Polymerized Toner Manufacturing Step

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

The monomer mixture uses an aromatic vinyl monomer or an acrylate monomer, a methacrylate monomer, a diene monomer or a mixture thereof and optionally an acidic or basic olefin monomer and other additives described above.

 (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 adding silica and polyester particles having a volume average particle diameter of 50 to 500 nm to the polymerized toner core using a Henschel mixer, the external additive is 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, after stirring for 10 minutes at room temperature, the temperature was raised to 70 ℃, the reaction temperature, and stirred for another 20 minutes To prepare an aqueous dispersion.

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 stirred for 20 minutes in 5 parts by weight of paraffin wax to prepare a monomer mixture, and homogenized at 13000 rpm using an aqueous dispersion and a homogenizer to form fine droplets in the aqueous dispersion. The monomer mixture was dispersed and then reacted for 15 hours while stirring at 200 rpm with a paddle type stirrer to prepare a polymerized toner.

(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)

Using Henschel mixer, 2 parts by weight of silica and 0.5 parts by weight of polyester particles having a volume average particle diameter of 100 nm were added to 100 parts by weight of the polymerized toner core, and then the external additive was polymerized toner for 7 minutes at high speed at 5000 rpm. The core surface was coated.

 [Example 2]

In Example 1, the polymerization toner was obtained in the same manner as in Example 1 except that the amount of the polyester particles added was 0.2. 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 amount of the polyester particles added was 1.5. 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 volume average particle diameter of the polyester particles was 300 nm. 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 polyester 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 amount of the polyester particles added was 0.05. 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 volume average particle diameter of the polyester particles was 1,000 nm. The evaluation results are shown in Table 1.

[Experimental Example]

(Consumption and 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 square sheets of 19 cm by 1.5 cm on A4 paper, and then measure the weight of the supply again to consume the toner. Was calculated.

Consumption (g) = 1,000 sheets before printing Supplier  Weight-After 1,000 sheets print Supplier  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.

Wasted Amount of toner (g) = After 1,000 copies Drum  Weight-1,000 sheets before printing Drum  weight

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.

(Image uniformity)

After full printing on A4-size paper with a laser printer (HP2600, HP), the image density is measured by measuring the image density of four corners and one center of the paper using the image density meter (RD918, Macbath). Is less than 0.05, the image unevenness was judged to be uniform, and if the difference was less than 0.1, the image uniformity was judged to be normal, and if the difference was more than 0.1, the image was judged to be uneven.

Polyester volume average particle diameter (nm) Polyester addition amount (part by weight) Toner Consumption (g) Toner Transfer Efficiency (%) Image uniformity Example 1 100 0.5 19 96 Uniformity 2 100 0.2 20 95 Uniformity 3 100 1.5 19 95 Uniformity 4 300 0.5 20 96 Uniformity Comparative Example 1 - - 20 92 Not uniform 2 100 0.05 19 93 Not uniform 3 1000 0.5 25 85 Not uniform

Claims (15)

A polymerized toner in which an external additive is coated on a polymerized toner core, wherein the external additive uses silica and polyester particles together. The method of claim 1, The polymerized toner, characterized in that the volume average particle diameter of the polyester particles is 50 ~ 500nm. The method of claim 1, The content of the polyester particles is polymerized toner, characterized in that 0.1 to 2 parts by weight based on 100 parts by weight of the polymerized toner core. The method of claim 1, The polymerized toner core is prepared by polymerizing a monomer mixture including a binder resin monomer and a charge control agent. 5. The method of claim 4, The binder resin monomer is an aromatic vinyl monomer, an acrylate monomer, a methacrylate monomer, a diene monomer, or a mixture thereof. 5. The method of claim 4, The binder resin is a polymerized toner further comprising an acidic olefin monomer or a basic olefin monomer. 5. The method of claim 4, The charge control agent is a nigrosin-type acid dye, a 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, acid Polymerized toner, characterized in that the polyester containing, sulfonylamine of copper phthalocyanine, styrene-acrylic polymer containing a sulfonic acid group, or a mixture thereof. 5. The method of claim 4, The monomer mixture further comprises one or more additives selected from the group consisting of waxes, crosslinkers, molecular weight regulators and reaction initiators. 9. The method of claim 8, The wax is a paraffin wax, microcrystalline wax, ceresin wax, carnuba wax, ester wax, polyethylene wax, polypropylene wax, or a mixture thereof. 9. The method of claim 8, The crosslinking agent is divinylbenzene, ethylene dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,6-hexamethylene diacrylate, allyl methacrylate, 1,1,1-trimethylol Polymerized toner, characterized in that propane triacrylate, triallylamine, tetraallyloxyethane or a mixture thereof. 9. The method of claim 8, The molecular weight regulator is a t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, carbon tetrachloride, carbon tetrabromide or a mixture thereof. 9. The method of claim 8, 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, reaction initiator Polymerized toner comprising 0.01 to 5 parts by weight, 1 to 5 parts by weight of silica and 0.1 to 2 parts by weight of polyester. Mixing the dispersion stabilizer with water to prepare an aqueous dispersion; Homogenizing the monomer mixture of claim 4 in the aqueous dispersion to disperse the monomer mixture in the form of fine droplets in the aqueous dispersion; Polymerizing the homogenized monomer mixture; Washing and drying the polymerized polymer toner core; And Coating the polymerized toner core with an external additive; Polymerized toner manufacturing method comprising a. 14. The method of claim 13, 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. 14. The method of claim 13, 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%.