KR20130042814A - Polymerized toner and method of producing the same - Google Patents

Abstract

The present invention relates to a polymerized toner comprising a wax having a weight average molecular weight in the range of 300 to 1,000 and having an oil content of 1% or less, and a method of manufacturing the same, wherein the toner can realize high glossiness and hot-offset temperature, It can be applied in various fields such as the phenomenon.

Description

Polymerized Toner and Method for Producing the Same {Polymerized Toner and Method of Producing the same}

The present invention relates to a polymerized toner and a manufacturing method thereof.

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

In general, there are two methods for producing a toner, a production method using pulverization and a production method using polymerization. In the manufacturing method using pulverization, toner particles are prepared by putting together resin and pigment through a melt-mixing process, melt-mixing or 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 a 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. As a production method of a toner by a polymerization method, an emulsion polymerization method (aggregation method) and a suspension polymerization method are known. Since the emulsion polymerization method is difficult to control the size distribution of the particles and there is a problem in the quality reproducibility of the produced toner, the toner production method by suspension polymerization is more preferred.

The toner produced by suspension polymerization is prepared by uniformly dispersing various additives such as binder resin monomers, pigments, waxes, charge control agents or initiators to prepare monomer mixtures, and dispersing such monomer mixtures in the form of fine droplets in aqueous dispersions. After the polymerization process. However, the toner produced by suspension polymerization generates gloss and hot-offset as compared to the toner produced by emulsion polymerization (aggregation method) in which wax is located inside the toner, and wax is dispersed and dispersed throughout the toner. The disadvantage is that the temperature is low.

Therefore, it is necessary to improve the glossiness and hot-offset temperature by allowing the wax to uniformly disperse and form several domains in the toner particles. Conventionally, two or more waxes are mixed and used in toner particles. By using a mixture of waxes, several wax domains can be formed in toner particles. However, when using a mixture of waxes, fine wax domains of less than 100 nanometers are located near the surface of the toner particles, causing developer contamination by wax, resulting in lowered transfer efficiency and uneven image on printing. Generates.

The present invention is to provide a polymerized toner capable of realizing excellent glossiness and high hot-offsen temperature and a method of manufacturing the same.

The toner according to the present invention may include a wax having a weight average molecular weight in the range of 300 to 1,000 and an oil content of 1% or less.

In addition, the method of manufacturing the toner may include forming a monomer mixture comprising a monomer for a binder resin and a wax; And suspending polymerizing the monomer mixture to form toner particles, wherein the wax may have a weight average molecular weight in the range of 300 to 1,000 and an oil content of 1% or less.

The toner according to the present invention can realize high glossiness and hot-offset temperature, and can be applied in various fields such as development of electrophotographic.

1 is a Transmission Electron Microscope (TEM) photographs of toner particles according to one embodiment of the present invention;
2 and 3 are transmission electron microscope pictures of toner particles prepared by Comparative Examples, respectively.

The present invention relates to a toner comprising a wax having a weight average molecular weight in the range of 300 to 1,000 and an oil content of 1% or less, and a manufacturing method thereof.

Hereinafter, the toner according to the present invention will be described in detail.

The present invention provides a toner comprising a wax having a weight average molecular weight of 300 to 1,000 and an oil content of 1% or less. The oil content of the wax was calculated by dividing the wax powder (crystal) and the oil (solution) by using a solvent and the amount dissolved in the solvent as the oil content (by weight). The oil content in the wax has a great influence on the properties of the wax. The oil content serves as a factor in determining the physical properties such as, for example, the tensile strength, hardness, gloss and melting point of the wax. For example, the oil content can range from 0.001 to 1%, or from 0.1 to 1.0%, or from 0.2 to 0.8%.

The content of the wax in the toner is not particularly limited, but may be 0.1 to 15 parts by weight, specifically 1 to 25 parts by weight, and more specifically 5 to 15 parts by weight based on the total weight of the toner. The toner may include a wax and a binder resin, and may further include additives of any one or more of a pigment, a pigment dispersant, a charge control agent, a reaction initiator, a crosslinking agent, a molecular weight control agent, a lubricant, and a coupling agent. For example, the toner particles may be 50 to 95 parts by weight, specifically 60 to 93 parts by weight, more specifically 70 to 90 parts by weight, based on the total weight of the toner; 1 to 20 parts by weight of the pigment, specifically 2 to 15 parts by weight, more specifically 3 to 10 parts by weight; 0.1 to 20 parts by weight, specifically 0.2 to 15 parts by weight, more specifically 0.3 to 10 parts by weight of the pigment dispersant; 0.1 to 5 parts by weight, specifically 0.3 to 4 parts by weight, more specifically 0.5 to 3 parts by weight of the charge control agent; And 0.1 to 30 parts by weight of wax, specifically 1 to 25 parts by weight, and more specifically 5 to 15 parts by weight. Other remaining additives may be used in appropriate amounts.

The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the wax is 1.5 or less, specifically 1.0 to 1.5, more specifically 1.2 to 1.4 range. In this invention, the wax excellent in fixability can be manufactured by using the wax with a low ratio (Mw / Mn) of a weight average molecular weight (Mw) and a number average molecular weight (Mn). When the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the wax exceeds 1.5, there is a wax that is unmelted in the fixing roll during printing, which may act as a cause of lowering the fixing property. have.

The wax may be a paraffin wax. In addition, microcrystalline wax may also have a similar effect by producing an oil content of 1% or less through purification. For example, the wax may further include any one or more of polyethylene wax, polypropylene wax, ester wax, canova wax, and ceresin wax.

The toner according to the present invention may include a binder resin. The content of the binder resin may be 50 to 95 parts by weight based on the total weight of the toner.

The kind of binder resin can apply the polymer or copolymer of all the monomers which can be used for the toner manufactured by the polymerization method without particular limitation. For example, the binder resin may include one or more polymers or copolymers selected from the group consisting of styrene monomers, acrylate monomers, methacrylate monomers, diene monomers, and olefin monomers. The olefinic monomers may be optionally used alone or in combination of one or more of the acidic olefinic monomers and basic olefinic monomers.

Examples of the styrene monomers include styrene, monochlorostyrene, methyl styrene, and dimethyl styrene. The acrylate monomers include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate or 2-ethylhexyl acrylate. The methacrylate monomers include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, dodecyl methacrylate or 2-ethylhexyl methacrylate. The diene monomers include butadiene or isoprene. Examples of the olefinic monomers include acidic olefinic monomers and basic olefinic monomers. As the acidic olefin monomers, alpha, beta-ethylenically unsaturated compounds having a carboxyl group can be used, and as the basic olefin monomers, methacrylic acid esters, methacrylamides, vinyls of aliphatic alcohols having amine groups or quaternary ammonium groups An amine type, diallyl amine type, or the ammonium salt thereof can be used.

The manufactured toner may be in a particulate form, and the average particle diameter of the toner particles may be in the range of 1 to 20 μm, specifically 4 to 10 μm. Specifically, the particle size of the toner may be in the range of 5 to 8 μm, more specifically 6 to 7 μm. The average particle diameter of the toner particles may be 4 μm or more in terms of image density and scattering prevention, and the average particle diameter of toner particles may be 10 μm or less in terms of consumption reduction.

In addition, the toner particles may have a structure in which a coating film is formed. For example, the toner particles may have a structure in which a coating film containing silica, titanium dioxide, or a mixture thereof is formed. The silica is preferably surface treated with a silane compound such as dimethyldichlorosilane, dimethylpolysiloxane, hexamethyldisilazane, aminosilane, alkylsilane or octamethylcyclotetrasiloxane. The titanium dioxide may be used alone or in combination of those having a stable rutile at high temperature or anatase structure at low temperature, and having a particle size of 80 to 200 nm, specifically, 100 to 150 nm. Applicable

The toner according to the present invention may further include any one or more of a pigment, a pigment dispersant, a charge control agent, a reaction initiator, a crosslinking agent, a molecular weight regulator, a lubricant and a coupling agent.

The kind of the pigment is not particularly limited, and may include, for example, carbon black.

The pigment dispersant is for improving the stability of the pigment in the toner particles. As the pigment dispersant, a styrene-butadiene-styrene (SBS) copolymer having a weight average molecular weight of 2,000 to 200,000 may be used. If the weight average molecular weight of the pigment dispersant is less than 2,000, it may not be able to sufficiently function as a carbon black dispersant due to its high compatibility with the binder resin, and if it exceeds 200,000, the viscosity of the monomer mixture may be too high to deteriorate dispersion stability and polymerization stability. Ultimately, problems may arise that widen the particle size distribution. Specifically, the content of styrene and butadiene in the copolymer may be 10:90 to 90:10 by weight. If the content of the styrene exceeds 90%, butadiene block length is shortened, the high compatibility with the binder resin may not play a sufficient role of the carbon black dispersant, less than 10% to fully serve the carbon black dispersant However, the short styrene block length may result in insufficient control of pigment-to-pigment action, ie, carbon black to carbon black action.

Charge control agents may include cationic charge control agents, anionic charge control agents or mixtures thereof. Cationic charge control agents include nigrosine dyes, high aliphatic metal salts, alkoxy amines, chelates, quaternary ammonium salts, alkylamides, fluorine treatment actives, metal salts of naphthalene acid, or mixtures thereof, and the like. Chlorinated paraffins, chlorinated polyesters, polyesters containing acids, sulfonylamines of copper phthalocyanine, sulfonic acid groups or mixtures thereof and the like.

In addition, a copolymer having a sulfonic acid group may be used as the charge control agent. As the copolymer having a sulfonic acid group, for example, a copolymer having a sulfonic acid group having a weight average molecular weight of 2,000 to 200,000 can be used. If the weight average molecular weight is less than 2,000, the high compatibility with the binder resin may lower the surface concentration and may not function as a charge control agent. If the weight average molecular weight is more than 200,000, the viscosity of the monomer mixture may increase due to the high molecular weight, which is preferable for polymerization stability and particle size distribution. I can't. More specifically, as the copolymer having a sulfonic acid group, a copolymer having a sulfonic acid group having an acid value of 1 to 40 mgKOH / g and a glass transition temperature of 30 to 120 ° C may be used. If the acid value is less than 1, it does not function as a charge control agent, and if it exceeds 40, it affects the interfacial properties of the monomer mixture and deteriorates polymerization stability. In addition, when the glass transition temperature is lower than 30 ° C., the low glass transition temperature of the charge control agent exposed to the surface may cause friction-melting of the toner to the toner during printing, which may cause a blocking phenomenon. It is excessively hard to make it unfavorable for the properties of coating and fixability. Specific examples of the copolymer having a sulfonic acid group may include a styrene-acrylic copolymer having a sulfonic acid group, a styrene-methacrylic copolymer having a sulfonic acid group, or a mixture thereof, but is not limited thereto.

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 calcium persulfate and ammonium persulfate, etc. can be used, Among these, 1 type (s) or 2 or more types can be used in mixture.

Crosslinking agent divinylbenzene, ethylene dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, 1,6-hexamethylene diacrylate, allyl methacrylate, 1,1,1-trimethylolpropane Triacrylate, triallylamine, tetraallyloxyethane or mixtures thereof.

The molecular weight modifier may include t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, carbon tetrachloride or mixtures thereof.

As the lubricant and the coupling agent, those known to be applicable to the production of the polymerized toner may be used without particular limitation. For example, oleic acid or stearic acid can be used as a lubricant.

The toner according to the present invention may have a glossiness of 35 or more and a hot-offset temperature of printing paper of 160 ° C or more. Specifically, the polymerized toner according to the present invention may have excellent physical properties capable of realizing a uniform image with high glossiness and hot-offset temperature with a narrow particle size distribution. In particular, when the polymerized toner of the present invention is used, the glossiness is 35 or more, and the hot-offset temperature is 160 ° C or more in printing paper, which is particularly useful for printing electrophotographic images.

Hereinafter, a toner manufacturing method according to the present invention is provided.

In one embodiment, the toner manufacturing method,

Forming a monomer mixture comprising a monomer for a binder resin and a wax; And

Suspension polymerizing the monomer mixture,

The wax may have a weight average molecular weight in the range of 300 to 1,000 and an oil content of 1% or less.

For example, the oil content can range from 0.001 to 1%, or from 0.1 to 0.8%, or from 0.2 to 0.8% (by weight).

The polymerized toner produced by the method according to the present invention not only shows high glossiness when applied to printing but also can realize high hot-offset temperature. In addition, the application of such a polymerized toner can be effectively applied to fields such as photo printing requiring high glossiness.

The wax may be a paraffin wax. In addition, microcrystalline wax may also have a similar effect by producing an oil content of 1% or less through purification. In addition, the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the wax may be 1.5 or less, specifically 1.0 to 1.5, and more specifically 1.2 to 1.4. Details of the wax are as described above.

In the step of forming the monomer mixture, a binder resin monomer; Wax; And pigments dispersed in the binder resin, pigment dispersants, charge control agents and the like. For example, 50 to 95 parts by weight, specifically 60 to 93 parts by weight, more specifically 70 to 90 parts by weight, based on the total weight of the toner; 1 to 20 parts by weight of the pigment, specifically 2 to 15 parts by weight, more specifically 3 to 10 parts by weight; 0.1 to 20 parts by weight, specifically 0.2 to 15 parts by weight, more specifically 0.3 to 10 parts by weight of the pigment dispersant; 0.1 to 5 parts by weight, specifically 0.3 to 4 parts by weight, more specifically 0.5 to 3 parts by weight of the charge control agent; And 0.1 to 30 parts by weight of wax, specifically 1 to 25 parts by weight, and more specifically 5 to 15 parts by weight.

In one embodiment, in the step of forming the monomer mixture, the binder resin monomer and the wax are mixed, and any one or more of a pigment, a pigment dispersant, a charge control agent, a reaction initiator, a crosslinking agent, a molecular weight regulator, a lubricant and a coupling agent may be further mixed. Can be. For example, the step of forming the monomer mixture is 10 parts by weight or less or 0.1 to 10 parts by weight, specifically 8 parts by weight or 0.3 to 8 parts by weight, more specifically 5 parts by weight or 0.5 to 5 parts by weight; 5 parts by weight or less, or 0.01 to 5 parts by weight, specifically 4 parts by weight or 0.05 to 4 parts by weight, more specifically 3 parts by weight or 0.1 to 3 parts by weight; Or 10 parts by weight or less, or 0.1 to 10 parts by weight, specifically 8 parts by weight or less, or 0.3 to 8 parts by weight, more specifically 5 parts by weight or 0.5 to 5 parts by weight; A suitable amount of lubricant (e.g., oleic acid, stearic acid, etc.), for example, up to 5 parts by weight or 0.01 to 5 parts by weight, specifically 4 parts by weight or less or 0.05 to 4 parts by weight, more specifically 3 parts by weight or less To 3 parts by weight; An appropriate amount of coupling agent, such as 5 parts by weight or less, or 0.01 to 5 parts by weight, specifically 4 parts by weight or 0.05 to 4 parts by weight, more specifically 3 parts by weight or 0.1 to 3 parts by weight, etc. It can mix more than 1 type.

In another embodiment, the monomer mixture, 50 to 95 parts by weight of the binder resin; 1 to 20 parts by weight of pigment; 0.1 to 20 parts by weight of the pigment dispersant; 0.1 to 5 parts by weight of the charge control agent; 3 to 15 parts by weight of wax; And at least 10 parts by weight or 0.01 to 10 parts by weight of each of at least one additive selected from the group consisting of a reaction initiator, a crosslinking agent, a molecular weight modifier, a lubricant, and a coupling agent.

In another embodiment, the monomer mixture is 50 to 95 parts by weight of monomer for binder resin, 1 to 20 parts by weight of pigment, 0.1 to 20 parts by weight of pigment dispersant, 0.1 to 5 parts by weight of charge control agent, and 0.1 to 30 parts by weight of wax It may include wealth.

Specifically, the toner manufacturing method is

Forming an aqueous dispersion comprising a dispersant;

Preparing a monomer mixture comprising a monomer for a binder resin, a pigment, a pigment dispersant, a charge control agent and a wax; And

The monomer mixture may be added to the aqueous dispersion and suspended polymerized.

In the forming of the aqueous dispersion, the dispersant may be mixed with water to form the aqueous dispersion. Agitating or applying shear force may be applied to homogenize the aqueous dispersion. Specifically, the forming of the aqueous dispersion may include mixing calcium phosphate aqueous solution and calcium chloride aqueous solution to obtain calcium phosphate in the form of crystals on the aqueous solution. The calcium phosphate may be used as a dispersant, and the aqueous dispersion may have a form in which calcium phosphate crystals are uniformly dispersed in water.

The dispersant prevents aggregation between particles such as carbon black or monomer for binder resin present in the form of droplets in the aqueous medium, and enables the particles to be uniformly dispersed. The dispersant also serves to stabilize the droplet particles by adsorbing uniformly on the droplet surface. Such a dispersant may be solubilized by an acid or alkali treatment or warm water washing after the completion of the polymerization reaction in the aqueous medium and separated from the toner particles. The content of the dispersant may be applied in an amount of 1 to 5 parts by weight, specifically 2 to 4 parts by weight, and more specifically 2.5 to 3.5 parts by weight, based on 100 parts by weight of the monomer mixture.

Types of dispersants include inorganic dispersants, organic dispersants, anionic surfactants or mixtures thereof. Specific examples of the inorganic dispersant include calcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, hydroxy apatite, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, meta Calcium silicate, calcium sulfate, barium sulfate, bentonite, silica, alumina or mixtures thereof. In addition, specific examples of the water-soluble organic dispersant include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxy propyl cellulose, ethyl cellulose and carboxyl. Carboxyl methyl cellulose and its sodium salt, polyacrylic acid and its salt, starch or mixtures thereof, and the like. In addition, specific examples of the anionic surfactants include fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfate ester salts, dialkylsulfosuccinate salts, alkyl phosphates or mixtures thereof. More preferable examples of the dispersant include calcium phosphate. The calcium phosphate may be obtained in the form of crystals in an aqueous solution by mixing an aqueous sodium phosphate solution with an aqueous calcium chloride solution, and the aqueous dispersion may be in a form in which calcium phosphate crystals are uniformly dispersed in water.

In the preparing of the monomer mixture, a monomer resin for a binder resin, a pigment, a pigment dispersant, a charge control agent and a wax may be mixed and sufficiently dissolved to form a monomer mixture, and homogenized in an aqueous dispersion using a homogenizer. . In addition, the step of forming the monomer mixture may be performed after the addition of the pigment milling process at a constant stirring speed and milling time. For example, preparing the monomer mixture may include milling at a stirring speed of 8,000 to 20,000 rpm.

The monomer for binder resin used in the present invention may be any one or more selected from the group consisting of styrene monomer, acrylate monomer, methacrylate monomer, diene monomer and olefin monomer. The detailed description of the monomer for binder resin is as mentioned above. Two or more types of monomers may be mixed and used, and the type and content of the monomers to be mixed are not particularly limited.

In one embodiment, the binder resin monomer, (a) 30 to 95 parts by weight of a styrene monomer; And (b) 5 to 70 parts by weight of any one or more of an acrylate monomer, a methacrylate monomer, and a diene monomer.

In another embodiment, the binder resin monomer, (a) 30 to 95 parts by weight of a styrene monomer; (b) any one or more of an acrylate monomer, a methacrylate monomer and a diene monomer; And (c) any one or more of an acidic olefinic monomer and a basic olefinic monomer, wherein the content of the olefinic monomer may be 0.1 to 30 parts by weight based on the total weight of the monomers.

Suspending polymerization of the monomer mixture may include mixing the monomer mixture with an aqueous dispersion; Applying shear force to homogenize the monomer mixture into the aqueous dispersion in the form of droplets; And suspension polymerizing the homogenized monomer mixture.

The homogenization of the monomer mixture in the form of droplets in the aqueous dispersion by applying the shear force may be performed using a homerizer or the like. When the monomer mixture is uniformly dispersed in the form of fine water droplets (droplets) in the aqueous dispersion, the polymerization reaction proceeds. It is possible to form spherical toner particles of appropriate size. For dispersion in the form of fine droplets (droplets), a homogenizer may be applied to the monomer mixture and the aqueous dispersion using a homogenizer. For example, using a homogenizer, the monomer mixture mixed with the aqueous dispersion is homogenized at a speed of 5,000 rpm to 20,000 rpm, specifically 8,000 rpm to 17,000 rpm, so that the monomer mixture is dispersed in the form of fine droplets in the aqueous dispersion. You can.

In addition, the suspension polymerization of the homogenized monomer mixture may be performed for 8 to 20 hours at 60 to 90 ℃. More specifically, the suspension polymerization may be performed at 50 to 70 ° C. for 8 to 12 hours, and the reaction may be performed at a temperature of 80 to 110 ° C. for 30 minutes to 4 hours.

Toner production method according to the invention, after the step of suspending polymerization of the monomer mixture, the step of removing the dispersant by adding hydrochloric acid or nitric acid; And drying the toner particles.

Removing the dispersant may include adjusting to a pH suitable for dissolution of the dispersant. By adding a water-soluble inorganic acid such as hydrochloric acid or nitric acid to the dispersion in which the toner particles are formed, and adjusting the pH to 2 or less, specifically 1.5 or less, the dispersant can be dissolved in an aqueous solution and removed from the toner particles. In this dispersant removal step, after the pH is properly adjusted, the mixture is stirred for 5 hours or more to sufficiently dissolve the dispersant, and then a toner slurry containing less than 50 parts by weight of water may be obtained using a filtration device. In addition, in the step of removing the dispersant, a step of homogenizing the solution by applying shear force to the homogenizer and a separation step using a centrifugal separator may be applied. After the dispersant removal step described above, the dispersant may be more efficiently removed by repeating the removal of water using a filter device and the addition of excess distilled water several times.

Drying the toner particles includes placing the toner cake from which the dispersant is removed into a vacuum oven and vacuum drying at room temperature. However, the present invention is not limited thereto, and a drying method known to be commonly used in the preparation of the polymerized toner may be used without particular limitation.

In some cases, the toner manufacturing method according to the present invention may further include coating an inorganic powder including silica, titanium dioxide, or a mixture thereof on the surface of the toner particles. In this coating step, an inorganic powder including a separate external additive, for example, silica, titanium dioxide, or a mixture thereof, may be coated on the surface of the toner particle, and the coating step may be performed by using a Henschel mixer. After adding an external additive to a particle | grain, it can advance by the method of high speed stirring. The silica may be used without particular limitation as is known to be usable for the polymerized toner. The inorganic powders applicable in the coating step have been described above, and thus a detailed description thereof will be omitted.

The present invention will be described in more detail with reference to the following examples. The embodiments of the present invention are only for the detailed description of the present invention, and are not intended to limit the scope thereof.

Example  One

Preparation of Polymerized Toner

686 g of 0.1 M aqueous sodium phosphate solution and 100 g of 1 M calcium chloride were mixed with 500 g of water, and stirred at a reaction temperature of 70 ° C. for 20 minutes to prepare an aqueous dispersion in which calcium phosphate crystals were precipitated. The content of calcium phosphate in the aqueous dispersion was 3 parts by weight based on 100 parts by weight of the monomer mixture described below.

Monomer for binder resin of 160 g of styrene, 36 g of n-butyl acrylate, and 4 g of acrylic acid, 4 g of allyl methacrylate as a crosslinking agent, 0.4 g of n-dodecyl mercaptan as a molecular weight regulator, and a molecular weight of 10,000 as a pigment dispersant Styrene / 2EHA / anionic functional monomer copolymer, FCA 1001 NS, containing 3 g of styrene-butadiene-styrene (SBS) block copolymer and a sulfonic acid group having a weight average molecular weight of 16,500 4g of Fujikura Kasei) is mixed and dissolved in a 1 L container. 10 g of carbon black is added thereto, and the mixture is slowly stirred to allow carbon black to be impregnated into the monomer. Then, 70 g of 0.3 mm zirconium beads are added. After stirring at a speed of 10,000 rpm for 60 minutes, the beads were removed using a 200 mesh.

To the mixture from which the beads were removed, 20 g of paraffin wax (Fisher) having a molecular weight of 500, an oil content of 0.5%, and a weight average molecular weight (Mw) and a number average molecular weight (Mn) of 1.2 (Mw / Mn) was 1.2. Further addition and stirring was made to completely dissolve the wax in the mixture, and 5 g of azo nitrile initiator (Azo nitrile; V65, Waco Chemical) was added and stirred for 5 minutes to prepare a monomer mixture. At this time, the weight of the monomer mixture is 246.4 g.

The monomer mixture was added to the aqueous dispersion, and a shear force was applied at a speed of 13,000 rpm using a homogenizer to disperse and homogenize the monomer mixture in the form of fine droplets in the aqueous dispersion. Through the homogenization, the monomer mixture dispersed in the aqueous dispersion in the form of fine droplets was reacted at 60 ° C. for 10 hours while stirring at 200 rpm with a paddle type stirrer, and heated at 90 ° C. for 3 hours to further react to the slurry. A polymerized toner was prepared in an included form.

Toner Particle Cleaning and Drying

Hydrochloric acid was added to the slurry containing the polymerized toner to adjust the pH to 2 or less, and calcium phosphate was dissolved. After removing water using a filtration apparatus, distilled water was added twice as much as the total weight, diluted, homogenized by applying a shear force to a homogenizer, and then centrifugal separator (Beckman J2-21M, Rotor JA-14). Was centrifuged at 3,000 rpm for 15 minutes. This dilution, homogenization and centrifugation were repeated three times to remove calcium phosphate and other impurities on the toner surface.

Finally, after removing water through filtration, 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 was 7 µm, and the ratio (standard deviation) of the volume average particle diameter and the number average particle diameter was 1.26. At this time, the volume average particle diameter of the core was measured using a Coulter counter (Multisizer 3, Beckman coulter).

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 by stirring at a high speed at 5,000 rpm for 7 minutes.

Example  2

Toner was prepared and evaluated in the same manner as in Example 1 except that the Mw / Mn of the wax was adjusted to 1.3.

Example  3

Toner was prepared and evaluated in the same manner as in Example 1 except that the wax content was 0.8% and the molecular weight was adjusted to 250.

Example  4

Toner was prepared and evaluated in the same manner as in Example 1 except that the molecular weight of the wax was adjusted to 700.

Example  5

Toner was prepared and evaluated in the same manner as in Example 1 except that the wax content in the toner was adjusted to 13%.

Example  6

Toner was prepared and evaluated in the same manner as in Example 1 except that the molecular weight of the wax was adjusted to 400.

Example  7

10 g of ester wax, which is a synthetic wax, was added to 10 g of a paraffin wax (Fisher) in which the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) was 1.2. As a result, toner was prepared and evaluated in the same manner as in Example 1 by mixing paraffin wax and ester wax in a 1: 1 ratio.

Comparative example  One

Toner was prepared and evaluated in the same manner as in Example 1, except that PE wax (Poly wax500, Baker) was used.

Comparative example  2

Toner was prepared and evaluated in the same manner as in Example 1 except that an ester type wax (WE3, Japanese fat and oil) was used.

Comparative example  3

Toner was prepared and evaluated in the same manner as in Example 1 except that the oil content of the wax was adjusted to 3%.

Comparative example  4

Toner was prepared and evaluated in the same manner as in Example 1 except that the wax content in the toner was adjusted to 3%.

Comparative example  5

Toner was prepared and evaluated in the same manner as in Example 1 except that the Mw / Mn of the wax was adjusted to 3.

Comparative example  6

Toner was prepared and evaluated in the same manner as in Example 1 except that paraffin wax (10 g) and ceresin wax (10 g) were mixed at a ratio of 1: 1 to raise the molecular weight to 1500.

Experimental Example

The physical properties of the polymerized toners prepared according to Examples 1 to 2 and Comparative Examples 1 to 4 were evaluated as follows.

Glossiness

A laser printer (CP2025, manufactured by Hewlett-Packard) is used for front printing on A4-sized paper, and then the light is spun at an angle of 94 degrees using a micro-TRI-gloss (glossmeter). The glossiness of 4 corner parts and 1 center part was measured, and the average value was taken.

Hot-offset temperature

The hot-offset temperature was measured by varying the fixing temperature using an unfixed image by jamming in a printer at a constant speed of 30 ppm.

division Wax type Wax content
(Parts by weight) Wax molecular weight Oil content (%) Mw / Mn Glossiness Hot Offset (℃) Long-term burns
Characteristics (2.5k) Example 1 paraffin 8.1 500 0.5 1.2 35 175 Good Example 2 paraffin 8.1 500 0.5 1.3 35 175 Good Example 3 paraffin 8.1 250 0.8 1.2 36 175 Good Example 4 paraffin 8.1 700 0.5 1.2 34 170 Good Example 5 paraffin 13.0 500 0.5 1.2 37 185 Good Example 6 paraffin 8.1 400 0.5 1.2 36 175 Good Example 7 Paraffin / ester 8.1 600 0.5 1.3 34 160 Good Comparative Example 1 PE 8.1 500 - 1.3 28 130 500 images
Unevenness Comparative Example 2 Ester Wax 8.1 500 - - 30 135 Good Comparative Example 3 paraffin 8.1 500 3 1.2 34 170 500 image unevenness Comparative Example 4 paraffin 3 500 0.5 1.2 20 120 1 piece not settled
Occur Comparative Example 5 paraffin 8.1 500 0.5 3 24 180 Good Comparative Example 6 Paraffin / ceresin 8.1 1500 0.5 1.4 27 145 500 sheets of image unevenness

Along with the results of Table 1, the transmission electron microscope (TEM) photograph was taken for the prepared toner particles and are shown in FIGS. 1 to 3.

1 is photographs taken of the toner particles prepared in Example 1. FIG. Referring to FIGS. 1A and 1B, it can be seen that the curvature of the wax domain in the toner is smooth (high surface tension), and there is almost no small white wax domain distribution outside the toner. In addition, it can be seen that the gloss is excellent due to the presence of the double wax domain.

Figure 2 is a photograph of the toner particles produced by Comparative Example 3, the oil content is adjusted to 3%. Referring to Figs. 2A and 2B, it can be seen that the curvature of the wax domain in the toner is not smooth (low surface tension), and small white wax domains are distributed outside the toner.

3 is a photograph of toner particles prepared by Comparative Example 2 using an ester-type synthetic wax. Referring to FIG. 3, it can be seen that white small wax domains are not distributed much outside of the toner, but are present as single wax domains in the toner, thereby degrading gloss.

Claims (22)

A toner comprising a wax having a weight average molecular weight in the range of 300 to 1,000 and an oil content of 1% or less. The method of claim 1,
A toner having a wax content of 5 to 30 parts by weight based on the total weight of the toner. The method of claim 1,
The wax has a toner having a ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of 1.5 or less. The method of claim 1,
The wax is a paraffin wax or a microcrystalline wax. The method of claim 4, wherein
The wax further includes any one or more of polyethylene wax, polypropylene wax, ester wax, canova wax, and ceresin wax. The method of claim 1,
Toner comprising 50 to 95 parts by weight of the binder resin based on the total weight of the toner. The method according to claim 6,
The toner resin includes at least one polymer or copolymer selected from the group consisting of styrene monomer, acrylate monomer, methacrylate monomer, diene monomer and olefin monomer. The method of claim 1,
The toner is in a particulate form, and the toner particles have an average particle diameter of 4 to 10 mu m. The method of claim 8,
A toner with a coating film containing silica, titanium dioxide or a mixture thereof formed on an outer surface of the toner particles. The method of claim 1,
A toner further comprising any one or more of a pigment, a pigment dispersant, a charge control agent, a reaction initiator, a crosslinking agent, a molecular weight regulator, a lubricant and a coupling agent. The method of claim 1,
A toner having a glossiness of 35 or more and a hot-offset temperature on printing paper of 160 ° C or higher. Forming a monomer mixture comprising a monomer for a binder resin and a wax; And
Suspension polymerizing the monomer mixture,
The wax has a weight average molecular weight ranging from 300 to 1,000 and an oil content of 1% or less. 13. The method of claim 12,
Forming an aqueous dispersion comprising a dispersant;
Preparing a monomer mixture comprising a monomer for a binder resin, a pigment, a pigment dispersant, a charge control agent and a wax; And
Adding a monomer mixture to an aqueous dispersion and suspending polymerization. The method of claim 13,
Preparing the monomer mixture,
A toner manufacturing method comprising milling at a stirring speed of 8,000 to 20,000 rpm. 13. The method of claim 12,
The binder resin monomer is a toner manufacturing method comprising any one or more polymers or copolymers selected from the group consisting of styrene monomers, acrylate monomers, methacrylate monomers, diene monomers and olefin monomers. 13. The method of claim 12,
The monomer for binder resin is
(a) 30 to 95 parts by weight of styrene monomer; And
(b) 5 to 70 parts by weight of any one or more of an acrylate monomer, a methacrylate monomer and a diene monomer. 13. The method of claim 12,
The monomer for binder resin is
(a) 30 to 95 parts by weight of styrene monomer;
(b) any one or more of an acrylate monomer, a methacrylate monomer and a diene monomer; And
(c) at least one of an acidic olefinic monomer and a basic olefinic monomer,
The content of the olefin monomer is 0.1 to 30 parts by weight based on the total weight of the monomers. 13. The method of claim 12,
Suspending polymerization of the monomer mixture,
Mixing the monomer mixture with the aqueous dispersion;
Applying shear force to homogenize the monomer mixture into the aqueous dispersion in the form of droplets; And
A toner manufacturing method comprising the step of suspension polymerizing a homogenized monomer mixture. The method of claim 18,
Applying the shearing force to homogenize the monomer mixture in the form of droplets in the aqueous dispersion,
A toner manufacturing method comprising homogenizing a monomer mixture mixed with an aqueous dispersion using a homogenizer at a speed of 5,000 to 20,000 rpm. The method of claim 18,
Suspending polymerization of the homogenized monomer mixture,
Toner manufacturing method comprising the suspension polymerization reaction at 50 to 70 ℃ for 8 to 12 hours, the reaction for 30 minutes to 4 hours at a temperature of 80 to 110 ℃. 13. The method of claim 12,
After the step of suspending polymerizing the monomer mixture,
Adding hydrochloric or nitric acid to remove the dispersant; And
Toner manufacturing method further comprises the step of drying the toner particles. 13. The method of claim 12,
A method of manufacturing a toner, the method comprising: coating an inorganic powder comprising silica, titanium dioxide, or a mixture thereof on a surface of a toner particle.

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