KR101825915B1 - Method for preparing toner - Google Patents

Abstract

A manufacturing method of a toner is disclosed. In the production method of the toner of the present invention can be manufactured in a fixing property, transparency and gloss are excellent toner particles by adjusting the T _1/2 value of the polyester resin dispersion.

Description

TECHNICAL FIELD The present invention relates to a method for preparing toner,

The present invention relates to a toner manufacturing method, and more particularly, to a toner manufacturing method excellent in fixability, transparency and gloss.

Generally, the toner is produced by adding a coloring agent, a releasing agent and the like to a thermoplastic resin serving as a binder resin. Further, inorganic fine powder such as silica or titanium oxide may be added to the toner as an external additive in order to impart fluidity to the toner or improve physical properties such as charge control or cleaning property. Examples of the method for producing such a toner include a physical method such as a pulverization method and a chemical method such as a suspension polymerization method and an emulsion aggregation method.

Among the above chemical methods, since the toner manufacturing method by emulsion aggregation involves radical polymerization, only vinyl resin can be used as the binder resin. However, in this case, the polymerization is not completely terminated, and unreacted monomers, surfactants, etc. remain in the toner particles, so that the charge characteristics of the toner particles are deteriorated, and unpleasant odor due to volatile organic compounds (VOC) at the time of printing becomes a problem.

On the other hand, in the method of producing toner by suspension polymerization, a toner is prepared by mixing styrene-acrylate monomer and low molecular weight polyester resin together, and unreacted monomers remain in the toner, and the binder resin is dissolved There is a problem that the residual organic VOC content is large. In addition, since the carboxyl group exists on the surface of the polyester resin, the cohesive force varies depending on the content and type of the coagulant used in the coagulation process using the coagulant, which may lead to rapid growth and low growth of particles in the coagulation process and coalescence process. Careful attention is required.

The polyester resin has advantages such as improved pigment dispersibility, excellent transparency, low fixation temperature and narrow range of glass transition temperature than vinyl-based resins such as styrene-acrylic copolymer resin, Suitable as a resin.

As a method for producing a toner using a polyester resin as a binder resin, toner particles are agglomerated using a polyaluminum chloride (PAC) as a coagulant in a mixture of a polyester resin dispersion, a colorant dispersion and a wax dispersion, There is a method of preparing toner particles through a freezing / coalescence process.

Japanese Patent Laid-Open No. 2003-107798 discloses a having a weight average molecular weight of the gel portion was measured to 0.3% by weight, GPC method 3000 to 20,000, a number average molecular weight of 1,000 to 5,000, PDI of from 2 to 10, the T _1/2 (A) having a gel fraction of 2% by weight or less, a weight average molecular weight measured by GPC method of 200,000 to 2,000,000, a number average molecular weight of 5,000 to 20,000 and a PDI of 10 to 400, A binder resin containing a polyester resin (B) having a T _1/2 of 150 ° C to 250 ° C, and a colorant. In this method, since the gel content of the polyester resin (B) is too high, it may take a long time to dissolve in an organic solvent, and transparency and glossiness may occur in printing.

Therefore, an object of the present invention is to provide a method for producing a toner which is excellent in transparency, glossiness and fixability in a method of producing a toner using a polyester resin as a binder resin.

In order to solve the above problems,

A mixture of a polyester resin dispersion, a colorant dispersion, and a wax dispersion;

Adding a flocculant to the mixed liquid to agglomerate the toner particles; And

And aggregating the aggregated toner particles, characterized in that the polyester resin dispersion has a T _1/2 value of from 130 to 145 ° C as measured by a constant-load extrusion type tubular rheometer Is provided.

According to one embodiment of the present invention, the polyester resin may have a weight average molecular weight of 18,000 to 30,000, a number average molecular weight of 5,000 to 7,000, a PDI of 4 to 10, and a MP of 5,000 to 8,000.

According to another embodiment of the present invention, the polyester resin may have an acid value of 10 to 12 mg KOH / g.

According to another embodiment of the present invention, the polyester resin dispersion may have a solid content of 23 wt% to 45 wt%.

According to the production method of the present invention, toner particles excellent in transparency, gloss and fixability can be provided.

1 is a graph showing one embodiment of a flow curve of a sample by a temperature elevation method using a constant load extrusion type tubular rheometer.

Hereinafter, preferred embodiments of the present invention will be described in detail.

A method of manufacturing a toner according to an aspect of the present invention includes the steps of: preparing a mixture of a polyester resin dispersion, a colorant dispersion, and a wax dispersion;

Adding a flocculant to the mixed liquid to agglomerate the toner particles; And

And a step of combining the agglomerated toner particles, wherein the polyester resin dispersion has a T _1/2 value of from 130 캜 to 145 캜 as measured by a constant-load extrusion type tubular rheometer, / RTI >

The constant load extrusion type tubular rheometer described above is a means for easily measuring the performance such as the thermal property and the viscosity characteristic of the resin and the like and measures the viscous resistance when the melt passes through the tubules. For example, flow tester CFT-500 manufactured by Shimadzu Seisakusho. The measurement by the temperature elevation method using this apparatus is carried out by raising the temperature at a constant rate as the test time elapses, and the process from the sample to the transition from the solid state to the transition state and the rubber- Can be measured. With this device, the shear rate and viscosity of each temperature at the flow station can be measured easily.

The flow curve by the temperature elevation method is shown in Fig.

The AB region (softening curve) represents the step in which the sample is deformed under compressive load to gradually decrease the internal void.

Point B is the temperature at which the internal voids disappear and has a uniform distribution of the stress distribution and a uniform appearance of the transparent body or the like, and represents the inflection point from the solid state to the transition state. This temperature is defined as the softening temperature Ts.

The BC region (stop curve) shows no clear change in the position of the piston within a finite time, and also indicates a region from the die to the start of the sample flow, and the sample includes a rubber-like elastic region. In the case of the crystalline polymer, this region is short, and the softening temperature shows a value close to the flow starting temperature described later.

The point C represents the temperature at which the sample starts to flow out from the die of the flow meter due to the decrease in viscosity, and this temperature is defined as the flow-out start temperature (Tfb).

The CDE region (runoff curve) represents the region from which the sample flows out of the die and is mainly composed of an invisible viscous flow.

The melting temperature (T _1/2 ) by the 1/2 method is the temperature at _half the piston stroke of the flow meter between the outflow start temperature (Tfb) and the outflow end temperature (Tend) of the outflow curve.

When the T _1/2 of the polyester resin dispersion is in the above range, toner particles excellent in fixability, glossiness and transparency can be obtained regardless of the T _1/2 of the polyester resin itself used. That is, T _1/2 value of the toner particles I of a closely related to the fixing performance, gloss and transparency of the toner, T _1/2 value of the toner particles is linear with the T _1/2 value of the polyester resin dispersion enemy , The desired toner properties can be obtained by controlling the T _1/2 value of the polyester resin dispersion within the above range.

Conventionally, a polyester resin, but to adjust the T _1/2 value of its own to obtain the desired physical properties of the toner Here, the polyester resin itself of the T _1/2 value is not to be reflected in the T _1/2 value of the toner come constant There is a problem that the physical properties of the toner can not be obtained, and the range of selection of the polyester resin has to be narrowed. However, in the present invention, all of these problems can be solved. That is, it is not necessary to strictly define the T _1/2 value of the polyester resin itself, and the content of the dispersion component other than the polyester resin such as the dispersion stabilizer, especially the content of the dispersion stabilizer, is properly adjusted to obtain the desired toner properties.

The method of manufacturing the toner may further include washing and drying the combined toner particles.

In order to more specifically describe the method for producing the toner, the following processes are mainly divided into (A) a dispersion producing process, (B) an aggregating process, (C) a coagulation fixing and coalescing process, and (D) .

(1) Dispersion manufacturing process

The manufacturing process of the dispersion can be roughly classified into three types. That is, it includes polyester resin dispersion preparation, colorant dispersion preparation, and wax dispersion preparation.

The polyester resin dispersion can be obtained by adding a surfactant, a dispersant, a polyester resin and an organic solvent to an aqueous solvent, stirring the mixture, and then heating to remove the organic solvent. Alternatively, an organic solvent may be added to an aqueous solvent containing a surfactant and a dispersion stabilizer to prepare a solvent emulsion, and then the polyester resin may be put into a solid state to obtain a polyester dispersion.

Examples of the aqueous solvent include water, methanol, ethanol, butanol, acetonitrile, acetone, ethyl acetate and the like, most preferably water.

The polyester resin used in the present invention may have a glass transition temperature of 60 ° C to 70 ° C. The polyester resin preferably has a weight average molecular weight of 18,000 to 30,000, a number average molecular weight of 5,000 to 7,000, a PDI of 4 to 10, and a peak molecular weight (Mp) of 5,000 to 8,000, as measured by gel permeation chromatography have. When the Mp value is lower than the weight average molecular weight, the fixability of the toner is improved.

In the present invention, the peak molecular weight (Mp) in gel permeation chromatography (GPC) is a molecular weight determined from the peak value of the elution curve obtained by GPC measurement. The measurement conditions of the GPC measurement are as follows.

Device: manufactured by Toyo Soda Industry Co., Ltd., HLC8020

Column: TSKgelGMHXL (column size: 7.8 mm (ID) x 30.0 cm (L)), manufactured by Toyo Soda Kogyo Co., Ltd.,

Oven temperature: 40 ° C

Eluent: THF

From the retention time corresponding to the peak value of the elution curve obtained, a calibration curve was prepared using standard polystyrene to obtain peak molecular weight (Mp).

A-500 (molecular weight: 5.0 x 10 ² ), A-2500 (molecular weight: 2.74 x 10 ³ ) and F-2 (molecular weight: 1.96 x 10 ⁴ ) were used as a standard polystyrene sample for preparing a calibration curve. ), F-20 (molecular weight of ^{1.9 × 10 5), F-} 40 ( molecular weight of ^{3.55 × 10 5), F-} 80 ( molecular weight of ^{7.06 × 10 5), F-} 128 ( molecular weight of ^{1.09 × 10 6), F-} 288 ( (Molecular weight: 2.89 × 10 ⁶ ), F-700 (molecular weight: 6.77 × 10 ⁶ ), and F-2000 (molecular weight: 2.0 × 10 ⁷ ).

The peak value of the elution curve is the point at which the elution curve shows the maximum, and when the maximum value is 2 or more, the elution curve gives the maximum value. There is no particular limitation on the eluent, and in addition to THF, a solvent for dissolving the polyester resin, such as chloroform, may be used.

On the other hand, the PDI value of the polyester resin is not particularly limited, but if it is within the above range, the fixability of the obtained toner may be improved.

The acid value of the polyester resin is not particularly limited, but may preferably be 10 to 12 mg KOH / g.

As the dispersion stabilizer, an inorganic base of a monovalent metal can be used, and there are NaOH, LiOH, KOH and the like.

The polyester resin can be produced by polycondensation of an acid component and an alcohol component, and a polyester resin is produced mainly by using a polycarboxylic acid as an acid component and by using a polyhydric alcohol as an alcohol component.

Specific examples of the polyhydric alcohol component include polyoxyethylene- (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2,0) (2,2) -Polyoxyethylene- (2,0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2,3) Bis (4-hydroxyphenyl) propane, polyoxypropylene- (2,3) -2,2-bis Bis (4-hydroxyphenyl) propane, polyoxypropylene- (3,3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, 1,3-propylene glycol, 4-butylene glycol, 1,3-butylene glycol, glycerol, and polyoxypropylene. Specific examples of the polyvalent carboxylic acid component include aromatic polybasic acids and / or alkyl esters thereof which are conventionally used in the production of polyester resins. Examples of such aromatic polyvalent acids include terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid , 1,2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid, and the like, and / or alkyl esters of these carboxylic acids. Examples of the alkyl group include methyl, ethyl, have. The aromatic polybasic acid and / or the alkyl ester thereof may be used singly or in combination of two or more thereof.

Examples of the organic solvent used in the polyester resin dispersion include methyl acetate, ethyl acetate, isopropyl acetate, methyl ethyl ketone, dimethyl ether, diethyl ether, 1,1-dichloroethane, 1,2-dichloroethane, dichloromethane, And chloroform may be used, but the present invention is not limited thereto.

In the polyester resin dispersion, it is preferable to use the surfactant in an amount of 1 to 4 parts by weight and the organic solvent in an amount of 15 to 200 parts by weight based on 100 parts by weight of the polyester resin.

The dispersion stabilizer is preferably used in an amount of 0.2 to 3.0 parts by weight per 100 parts by weight of the polyester resin.

The polyester resin dispersion may have a solid content of 23 wt% to 45 wt%.

The aqueous solvent in the polyester resin dispersion may be used in an amount of 30 to 80 parts by weight per 100 parts by weight of the polyester resin, and the organic solvent may be used in an amount of 30 to 80 parts by weight per 100 parts by weight of the polyester resin.

The colorant dispersion may be dispersed in water using a dispersant such as a surfactant or may be dispersed using an organic solvent. When dispersing in water, an anionic surfactant and a nonionic surfactant are preferable as the dispersing agent, and an anionic surfactant is more preferable. By using the dispersing agent, it becomes easy to disperse the pigment in water, the dispersed particle size of the pigment in the toner can be reduced, and a toner having more excellent characteristics can be produced. Unnecessary dispersants can be removed by a subsequent washing process.

When a colorant is dispersed using an organic solvent, a dispersion is prepared by using a master batch in which a pigment and a polyester resin are kneaded. Specifically, a masterbatch pigment dispersion can be obtained by adding a master batch and an organic solvent to a ball mill and milling the mixture for about 24 hours, and then adding the mixture to water containing a surfactant and a dispersion stabilizer. It may be dispersed by the same method as the method for producing the polyester resin dispersion. The dispersion stabilizer used in this case may be a dispersion stabilizer such as NaOH used in the production of the polyester resin dispersion.

The use of a master batch pigment dispersion is superior in color development after toner production than when a pigment dispersion is used.

The colorant may be selected from black pigments, cyan pigments, magenta pigments, yellow pigments, and mixtures thereof, which are commonly used commercially.

The content of the colorant may be sufficient to color the toner and form a visible image upon development. For example, it is preferably 3 to 15 parts by weight based on 100 parts by weight of the polyester resin. If the content is less than 3 parts by weight, the coloring effect may be insufficient. If the content is more than 15 parts by weight, the electric resistance of the toner is lowered, and sufficient triboelectric charge can not be obtained.

The wax dispersion can be prepared by dispersing a natural or synthetic wax in water or an organic solvent.

As the wax, a known wax can be used. Natural waxes such as carnauba wax and rice wax; synthetic waxes such as polypropylene wax and polyethylene wax; petroleum waxes such as montan wax; alcohol waxes and ester waxes. The wax may be used alone, or two or more waxes may be used in combination.

When the wax is dispersed in water, a surfactant or a dispersion stabilizer is used and dispersed using a disperser such as a high-pressure homogenizer or the like to obtain a dispersion. When the wax is dispersed in an organic solvent, an organic solvent is added to water containing a surfactant and a dispersion stabilizer as in the production of a polyester resin dispersion to prepare a solvent emulsion, and the wax is put into a solid state to prepare a dispersion. The content of the wax is preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the polyester resin.

(B) Coagulation Process

The respective dispersions prepared in the above dispersion manufacturing process are mixed and agitated to add a flocculant and an acid to agglomerate the toner particles. The coagulation step is preferably carried out at room temperature, but it may be heated to around the glass transition temperature (Tg) of the polyester resin, and stirring the mixture of the respective dispersions by a mechanical shearing force using a stirrer is preferred, Aggregates can be formed in one particle state.

The inorganic salt of the monovalent metal used as the coagulant may be NaCl or KCl.

The amount of the flocculant to be used is 0.3 to 5% by weight, preferably 0.5 to 3% by weight, based on the total solids content of the flocculating step reaction solution. If the amount of the flocculant is less than 0.3 wt%, flocculation may not occur, and if it is more than 5 wt%, the flocculant particles may become too large.

The pH can be adjusted by adding an acid in the flocculation process, and the preferred pH may be 4.5 to 6.5.

The agglomeration may be performed by stirring the reaction solution at a temperature of 40 to 60 DEG C at a rate of 1.0 to 7.0 m / sec.

In the present invention, by using the inorganic salt of the monovalent metal as the flocculant, the monovalent metal ion derived from the inorganic base of the monovalent metal used as the dispersion stabilizer in the production of the polyester resin dispersion can serve as the coagulant auxiliary role, An excellent coagulation effect can be obtained.

 (C) Coagulation fixing and coalescing process

To freeze aggregation, the temperature of the reaction solution is maintained at 53 to 58 ° C and the pH is raised to 10.

To raise the pH at this time, an inorganic base such as NaOH, KOH or LiOH is added.

Then, the mixed liquid containing the toner particles is heated to uniformize the particle size and shape of the aggregated toner particles. It is preferable to adjust the particle diameter to be 1 to 20 占 퐉 by heating to a temperature not lower than the glass transition temperature (Tg) of the polyester resin, whereby toner particles having substantially uniform particle diameter and shape can be obtained.

It is possible to improve the surface properties of particles by heating to a temperature not lower than the glass transition temperature (Tg) of the polyester resin. However, before heating to a temperature not lower than the glass transition temperature (Tg) of the polyester resin, a polyester resin dispersion or polystyrene- The latex is put into the toner particles to wrap the toner particles generated in the coagulation process once, thereby preventing the pigment or wax contained therein from coming out and making the toner hard. The polyester resin dispersion or the polystyrene butyl acrylate latex to be added at this time may be a resin dispersion having the same physical properties (Tg, molecular weight) as the polyester resin dispersion used in the previous step, and may be a resin dispersion having a higher Tg and a higher molecular weight May be used. When Tg and molecular weight are higher, the Tg is preferably 60 to 85 ° C, and the molecular weight is preferably 10,000 to 300,000. In order to prevent the particle size from becoming large during the wrapping of the toner particles generated in the aggregating step with the resin dispersion to be added in this way, a surfactant is added or the pH is adjusted and the temperature is raised to the temperature higher than the glass transition temperature of the polyester resin The unification process can be carried out.

(D) Cleaning and drying process

And washing and drying the toner particles obtained in the coalescing process with water. In this process, the mixed liquid containing the toner is cooled to room temperature, the mixed liquid is filtered, the filtrate is removed, and the toner is washed with water. For cleaning, it is preferable to use pure water having a conductivity of 10 mu S / cm or less, and it is preferable to clean the toner until the filtrate from which the toner is washed has a conductivity of 50 mu S / cm or less. The cleaning of the toner using pure water may be performed in a batch-wise manner and continuously. Cleaning of the toner using pure water is performed to remove unnecessary components other than the toner component such as impurities that may affect the chargeability of the toner and unnecessary coagulants that do not participate in aggregation.

The toner obtained after the washing step is dried using a fluid bed drier, a flash jet dryer and the like.

Further, a desired external additive may be added to the toner obtained by drying.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these embodiments.

Production Example 1: Synthesis of polyester resin (1)

A 3L reactor equipped with a stirrer, a nitrogen gas inlet, a thermometer and a condenser was installed in an oil bath as a heating medium. 45 g of terephthalic acid, 39 g of isophthalic acid, 75 g of 1,2-propylene glycol and 3 g of trimellitic acid were charged into the reactor thus installed, and dibutyltin oxide was fed as a catalyst at 500 ppm based on the total weight of the monomers. The temperature of the reactor was raised to 150 캜 while stirring at 150 rpm. The reaction was continued for 6 hours, the temperature was raised to 220 ° C, the reactor was depressurized to 0.1 torr to remove adverse reaction products, and the reaction was carried out for 15 hours under the same pressure condition to obtain a polyester resin (1).

The polyester resin thus obtained had an acid value of 12 mgKOH / g, a weight average molecular weight of 26,000, a number average molecular weight of 6,400, an Mp value of 7,200 and a PDI of 4.0.

Production Example 2: Synthesis of polyester resin (2)

 137 g of dimethyl terephthalate, 55 g of dimethyl isophthalate, 68 g of ethylene glycol, 175 g of ethylene oxide adduct of bisphenol A and 0.1 g of tetrabutoxy titanate as catalyst were placed in an autoclave equipped with a stirrer, a thermometer and a stirrer and heated at 150 to 220 DEG C for 180 minutes And the transesterification reaction was carried out. Subsequently, the temperature was raised to 240 ° C, the pressure of the reaction system was gradually reduced, and after 30 minutes, the pressure was adjusted to 10 mmHg and the reaction was continued for 70 minutes. After the temperature was lowered to 200 ° C, 2.0 g of trimellitic acid was added and the reaction was carried out for 70 minutes to obtain a polyester resin (2).

The polyester resin thus obtained had an acid value of 10 mgKOH / g, a weight average molecular weight of 24,000, a number average molecular weight of 5,400, an Mp value of 6,400 and a PDI of 4.4.

Glass transition temperature (Tg, ℃) measurement

Using a differential scanning calorimeter (manufactured by Netzsch), the sample was heated from 20 ° C to 200 ° C at a heating rate of 10 ° C / minute, quenched to 10 ° C at a cooling rate of 20 ° C / minute, / Min. ≪ / RTI >

Acid value measurement

The acid value (mgKOH / g) was determined by dissolving the resin in dichloromethane, cooling, titrating with 0.1N KOH methyl alcohol solution.

Weight average molecular weight, number average molecular weight, Mp and PDI measurement

The weight average molecular weight, number average molecular weight, Mp and PDI of the binder resin were measured by gel permeation chromatography (GPC) using a calibration curve using a polystyrene reference sample.

From the holding time corresponding to the peak value of the elution curve obtained by the GPC method, the peak molecular weight (Mp) was determined by standard polystyrene conversion. The peak value of the elution curve is a point at which the elution curve indicates the maximum value, and when the maximum value is 2 or more, the maximum value of the elution curve is given. The signal intensity I (Mp) of the GPC curve at the position of the peak molecular weight and the signal intensity I (M100000) of the GPC curve at the position of the molecular weight of 100,000 are the signal intensity at the position of the peak molecular weight, The difference in the signal intensity of the line, the difference between the signal intensity at the position of the molecular weight of 100,000 and the signal intensity of the baseline, and is represented by the potential (.).

Device: manufactured by Toyo Soda Industry Co., Ltd., HLC8020

Column: TSKgelGMHXL (column size: 7.8 mm (ID) x 30.0 cm (L)), manufactured by Toyo Soda Kogyo Co., Ltd.,

Oven temperature: 40 ° C

Eluent: THF

Sample concentration: 4 mg / 10 ml

Filtration conditions: The sample solution was filtered with a 0.45 μm Teflon (registered trademark) membrane filter

Flow rate: 1 ml / min

Injection amount: 0.1 ml

Detector: RI

A-500 (molecular weight: 5.0 x 10 ² ), A-2500 (molecular weight: 2.74 x 10 ³ ), F-2 (molecular weight: 1.96 x 10 ⁴ ) F-20 (molecular weight of ^{1.9 × 10 5), F-} 40 ( molecular weight of ^{3.55 × 10 5), F-} 80 ( molecular weight of ^{7.06 × 10 5), F-} 128 ( molecular weight of ^{1.09 × 10 6), F-} 288 ( molecular weight 2.89 × 10 ⁶ ), F-700 (molecular weight: 6.77 × 10 ⁶ ) and F-2000 (molecular weight: 2.0 × 10 ⁷ ).

Glass transition
Temperature (Tg) Acid value
(mgKOH / g) Weight average
Molecular Weight Number average
Molecular Weight MP PDI Production Example 1 66 12 26,000 6,400 7,200 4.0 Production Example 2 67 10 24,000 5,400 6,400 4.4

Production Example 3: Preparation of polyester resin dispersion (1)

2400 g of the polyester resin (1) prepared above, 330 g of sodium hydroxide (4 wt%), 53 g of DOWFAX (DF2A1, BASF) and 4000 g of methyl ethyl ketone were placed in a double jacket reactor and stirred at 150 rpm, The temperature was raised to 95 ° C. After about 3 hours, when the internal temperature of the reactor reached 80 DEG C, the organic solvent was removed for about 10 hours. After the organic solvent was completely removed, the reaction solution was cooled to room temperature. The solid content of the dispersion was 23.0 wt%, the pH of the dispersion was 7.4, and the average particle size of the dispersed particles was 145 nm. The dispersion was dried, and the T _1/2 by the flow tester was 133 ° C.

Production Example 4: Preparation of polyester resin dispersion (2)

7200 g of deionized water, 4800 g of the polyester resin (2) prepared in Preparation Example 2, 552 g of sodium hydroxide (4 wt%), 105.6 g of DOWFAX (DF2A1, BASF) and 4800 g of methyl ethyl ketone were placed in the double jacket reactor, The temperature of the reactor was raised to 95 캜 while stirring. After about 3 hours, when the internal temperature of the reactor reached 80 DEG C, the solvent was removed for about 10 hours. When all of the solvent was removed, the solution was cooled to room temperature. The solid content of the dispersion was 40.0 wt%, the pH of the dispersion was 7.5, and the average particle size of the dispersed particles was 200 nm. Further, this dispersion was dried and the T _1/2 as measured by a flow tester was 138 占 폚.

T _1/2 by the constant load extrusion type tubular rheometer specified in the present invention is a value obtained by measuring under the following conditions:

Piston cross-sectional area: 1 cm ²

Cylinder pressure: 0.98 Mpa

Die length: 1 mm, die hole diameter: 0.5 mm

Measurement start temperature: 90 ° C

Heating rate: 3 ° C / min

Sample weight: 1.5 g

 Production Example 5: Preparation of masterbatch pigment dispersion

800 parts of polyester resin (1) and carbon black pigment (NIPEX 150 manufactured by Degussa, Germany) were mixed in an amount of 8: 2 by weight, 50 parts by weight of ethyl acetate was added based on 100 parts by weight of the resin, And dispersed with stirring in a kneader for 3 hours. The mixture was then mixed at a speed of 50 rpm using a twin-screw extruder connected to a vacuum apparatus, and the solvent ethyl acetate was removed using a vacuum apparatus to prepare a black pigment master batch.

60 g of the prepared black pigment masterbatch was placed in a container for ball mill and 0.5 kg of 3φ, 1φ and 0.5φ balls were added, and 200 g of methyl ethyl ketone was added and milled at 100 rpm for 24 hours. Since the dispersion obtained after milling is not yet uniformly dispersed, it is dispersed in a reactor containing 60 g of water, 4.3 g of surfactant and 10 ml of dispersion stabilizer to prepare a master batch pigment dispersion having a particle size of 0.8 탆. The organic solvent was removed by reducing the pressure to 0.3 torr at a temperature of 60 占 폚.

Production Example 6: Preparation of wax dispersion

A 1-L reactor equipped with a thermometer and an impeller-type stirrer was charged with 600 ml of water, followed by 25 ml of a 1 N sodium hydroxide solution as a dispersion stabilizer and 8.9 g of a surfactant.

Example 1

1052 g of the polyester resin dispersion (1) obtained in Production Example 3, 65.7 g of the black pigment dispersion of Production Example 5, 15.7 g of the cyan pigment liquid, 70.6 kg of the wax dispersion of Production Example 6, 854.3 g of deionized water And nitric acid solution (4%) were added. The mixture was stirred at 1000 rpm for about 3 minutes using a homogenizer. At this time, the viscosity of the mixed dispersion was 50 cp, and the particle size was measured to 5.9 탆 when measured with a Coulter Multisizer. After the homogenizer was separated, the temperature of the obtained reaction product was increased to 55 ° C. at 1 ° C. per minute, and the reaction proceeded for 5 hours to proceed coagulation. When the temperature reached 55 ° C, 160 g of a prepared flocculant (NaCl) was added, and the temperature was raised to 95 ° C to conduct the reaction for 5 hours. Thereafter, the solution was cooled to room temperature and filtered and washed with ultrapure water. The final toner particles were measured by a Coulter Counter through a drying process after the washing process. The particle size was 6.24 μm and the GSDp value was 1.23. The result of TVOC analysis of the final toner was 5 ppm or less.

Example 2

A toner was prepared in the same manner as in Example 1 except that the polyester resin dispersion (2) obtained in Preparation Example 4 was used.

At this time, the viscosity of the mixed dispersion was 58 cps, and the particle size was 5.85 占 퐉 as measured by a Coulter multisizer. The final toner had a particle size of 6.15 mu m and a GSDp value of 1.21 and was measured to be 5 ppm or less as a result of TVOC analysis of the final toner.

Comparative Example 1: Production of polyester resin dispersion (3)

2400 g of the polyester resin (1) prepared above, 600 g of sodium hydroxide (4 wt%), 53 g of DOWFAX (DF2A1, BASF) and 4000 g of methyl ethyl ketone were placed in a double jacket reactor and stirred at 150 rpm for 5 hours. The temperature was raised to 95 캜. After about 3 hours, when the internal temperature of the reactor reached 80 DEG C, the organic solvent was removed for about 10 hours. After the organic solvent was completely removed, the reaction solution was cooled to room temperature. The solid content of the dispersion was 23.0 wt%, the pH of the dispersion was 7.5, and the average particle size of the dispersed particles was 220 nm. The dispersion was dried and the T _1/2 measured by a flow tester was 125 ° C.

Comparative Example 2: Production of polyester resin dispersion (4)

To the double jacket reactor was added 7600 g of deionized water, 2400 g of the polyester resin (1) prepared above, 650 g of sodium hydroxide (4 wt%), 53 g of DOWFAX (DF2A1, BASF) and 4000 g of methyl ethyl ketone, The temperature was raised to 95 캜. After about 3 hours, when the internal temperature of the reactor reached 80 DEG C, the organic solvent was removed for about 10 hours. After the organic solvent was completely removed, the reaction solution was cooled to room temperature. The solid content of the dispersion was 23.0 wt%, the pH of the dispersion was 7.6, and the average particle size of the dispersed particles was 180 nm. The dispersion was dried, and the T _1/2 measured by the flow tester was 147 ° C.

Comparative Example 3

A toner was prepared in the same manner as in Example 1 except that the polyester resin dispersion (3) obtained in Comparative Example 1 was used.

At this time, the viscosity of the mixed dispersion was 65 cps, and the particle size was 6.0 mu m when measured with a Coulter multisizer. The final toner had a particle size of 6.85 mu m and a GSDp value of 1.32, which was measured to be 10 ppm or less as a result of TVOC analysis of the final toner.

Comparative Example 4

A toner was prepared in the same manner as in Example 1 except that the polyester resin dispersion (4) obtained in Comparative Example 2 was used.

At this time, the viscosity of the mixed dispersion was 69 cps, and the particle size was 6.3 mu m when measured with a Coulter multisizer. The final toner had a particle size of 6.97 mu m and a GSDp value of 1.38, which was measured to be less than 10 ppm as a result of TVOC analysis of the final toner.

The average particle size, circularity, image evaluation, gloss, fixability and transparency of the toner particles prepared in Examples 1 and 2 and Comparative Examples 3 and 4 were evaluated as follows and the results are shown in Table 3 .

(Average particle diameter)

The average particle diameter of the toner particles was measured using a Coulter Multisizer III (Beckman coulter, USA), the number of particles measured was 50000, and the aperture used was 100 占 퐉.

(Circularity)

FPIA-3000 (manufactured by Sysmex, Japan). In the roundness measurement using FPIA-3000, a measurement sample was prepared by adding an appropriate amount of a surfactant to 50 to 100 ml of distilled water, adding 10 to 20 mg of toner particles to the dispersion, and dispersing the dispersion in an ultrasonic disperser for 1 minute.

The circularity is automatically obtained from the FPIA-3000 by the following equation.

Circularity =

In the above expression, an area means an area of the projected toner, and a perimeter means a circumferential length of a circle having the same area as the projected toner. This value can have a value from 0 to 1, and the closer to 1, the more spherical.

(Image evaluation)

Image evaluation was performed with a digital full color printer CP 2025 (HP). The image density was measured using spectroeye spectrophotometer (GretagMacbeth).

ok: image density is 1.3 or higher

ng: image density is 1.3 or less

(Gloss evaluation)

The gloss evaluation was carried out by developing with a CP 2025 (HP) modified apparatus which is a digital full color printer. And measured using a gloss meter (GretagMacbeth).

ok: glossiness over 13

ng: glossiness less than 13

(Evaluation of fixing property)

Equipment: belt type fuser

Test unfixed image: 100% pattern

Test temperature: 160 ℃

Speed: 160 mm / sec

Dwell time: 0.08 sec

Using toner particles prepared by mixing 9.75 g of the toner particles prepared in Examples and Comparative Example under the above conditions, 0.2 g of silica (TG 810G; manufactured by Cabot), and 0.05 g of silica (RX50, manufactured by Degussa) An image was formed. Then, the fixability of the unfixed image was evaluated while changing the temperature of the fixing roller in a fixing tester modified so that the fixing temperature could be arbitrarily changed. After measuring the OD (Optical Density) of each fixed image, an 810 tape of 3M company was attached to the fixed image portion, and the tape was removed by reciprocating 5 times with 500 g of spindle, and the OD was measured. The fixability was calculated as follows.

Fixability (%) = [(OD after tape removal) / (OD before tape removal)] * 100

Fixing property A fixing temperature region of 90% or more was regarded as a fixing region of the toner.

Minimum Fusing Temperature (MFT): Minimum temperature above 90% fixability without cold-offset

HOT (Hot Offset Temperature): The minimum temperature at which a hot-offset occurs

Average particle diameter (占 퐉) GSDp Fusing temperature range (℃) Image density Glossiness Example 1 6.24 1.23 120 ~ 200 1.38 ok 16 ok Example 2 6.15 1.21 120 ~ 200 1.36 ok 15 ok Comparative Example 3 6.85 1.32 130 ~ 180 1.30 ok 14 ok Comparative Example 4 6.97 1.38 120-170 1.24 - 14 ok

As can be seen from the above table, the toner particles produced by the production method of the present invention have narrow particle size distribution, excellent fixing property, glossiness and transparency, and excellent image quality.

While the preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, the scope of protection of the present invention should be determined by the appended claims.

Claims (10)

A mixture of a polyester resin dispersion, a colorant dispersion, and a wax dispersion;
Adding a flocculant to the mixed liquid to agglomerate the toner particles; And
And aggregating the aggregated toner particles, the method comprising the steps of:
The polyester resin dispersion is dried and has a T _1/2 value measured by a constant-load extrusion-type tubular rheometer of 130 to 145 ° C,
The polyester resin dispersion is prepared by adding a polyester resin, a dispersion stabilizer, a surfactant, and an organic solvent to an aqueous solvent and then stirring to obtain a mixture; And
And heating the mixture to remove the organic solvent. delete The method according to claim 1,
Wherein the dispersion stabilizer is NaOH, LiOH or KOH. The method according to claim 1,
And washing and drying the toner particles after the combining step. The method according to claim 1,
Wherein the polyester resin has a weight average molecular weight of 18,000 to 30,000, a number average molecular weight of 5,000 to 7,000, a PDI of 4 to 10, a Mp (Max Peak Position) of 5,000 to 8,000 and an acid value of 10 to 12 mg KOH / g ≪ / RTI > The method according to claim 1,
Wherein the aqueous solvent is water. The method according to claim 1,
The organic solvent may be at least one selected from the group consisting of methyl acetate, ethyl acetate, isopropyl acetate, methyl ethyl ketone, dimethyl ether, diethyl ether, 1,1-dichloroethane, 1,2-dichloroethane, dichloromethane and chloroform By weight based on the total weight of the toner. The method according to claim 1,
Wherein the dispersion stabilizer is used in an amount of 0.2 to 3.0 parts by weight per 100 parts by weight of the polyester resin. The method according to claim 1,
Wherein the organic solvent is used in an amount of 15 to 200 per 100 parts by weight of the polyester resin. The method according to claim 1,
Wherein the solid content of the polyester resin dispersion is 23 wt% to 45 wt%.

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