KR20130054018A - Apparatus for adding external additive to toner parent particle and method of preparing toner using the apparatus - Google Patents

Abstract

PURPOSE: A manufacturing method of a toner using an apparatus for adding external additive is provided to obtain a toner without separation of the external additives from surface of a toner base particle by increasing adhesive strength. CONSTITUTION: An apparatus for adding external additive(100,200,300) comprises a container(110,210,310) with a bottom part and ceiling part; and a mixer(120,220,320) arranged in the container. The mixer comprises rotary shafts(121,221,321) arranged to be expanded to the bottom part, from the ceiling part; first mixing wings(122,123,222,223,322) coupled to the bottom part of the rotary shaft; and second mixing wings coupled to the ceiling part of the rotary shaft. A manufacturing method of a toner comprises a step of injecting a toner base particle and external additives, mixing the same by the mixer.

Description

Apparatus for adding external additive to toner parent particle and method of preparing toner using the apparatus}

An external device and a manufacturing method of a toner using the same are disclosed. More specifically, an external device equipped with a stirrer including two or more stirring blades spaced up and down, and a manufacturing method of a toner using the same are disclosed.

An image forming method using toner comprises: charging a photosensitive member in an image forming apparatus, exposing a desired image to the charged photosensitive member to form an electrostatic latent image, and a photosensitive member image-exposed the charged toner in a developer Transferring the developed toner image onto the paper, and fusing the toner on the paper with heat and pressure to fix it on the paper.

In the process of forming an image, the toner is moved according to the development, transfer, and fixing steps. The toner mobility between the steps is such as electrostatic force generated in the toner by frictional charging and fluidity of the toner. It depends greatly on the physical force. Therefore, it is important that the performance of the toner remains stable until the toner runs out.

However, as the printing proceeds, the external additive attached to the surface of the toner is dropped by the pressure applied to the toner, so that the external additive agglomerates to form agglomerates, which causes a problem that the durability of the toner is deteriorated.

One embodiment of the present invention provides an external device equipped with a stirrer including two or more stirring wings spaced apart vertically.

Another embodiment of the present invention provides a toner manufacturing method using the external device.

According to an aspect of the present invention,

A container having a bottom and a ceiling; And

A stirrer disposed in the vessel,

The stirrer provides an external device including a rotating shaft disposed to extend from the ceiling side toward the bottom portion, a first stirring blade coupled to the bottom side of the rotating shaft, and a second stirring blade coupled to the ceiling side of the rotating shaft. do.

The ratio of the diameter of the second stirring blade to the diameter of the first stirring blade may be 1/4 ~ 3/1.

The diameter of the second stirring blade may not be larger than the diameter of the first stirring blade.

The first stirring blade and the second stirring blade may be coupled to the rotary shaft in a direction crossing the longitudinal direction of the rotary shaft.

Both longitudinal ends of the first stirring blade may be bent toward the ceiling portion, and both longitudinal ends of the second stirring blade may be bent toward the bottom.

Another aspect of the invention,

In the external device, the toner base particles and the external additive are added and then stirred with the stirrer to provide an external toner.

The amount of the external additive may be 0.1 to 4.0 parts by weight based on 100 parts by weight of the toner base particles.

The particle size of the toner base particles may be 6 ~ 10㎛, the particle size of the external additive may be 5 ~ 200nm.

The stirring may be performed for 1 to 30 minutes at a speed of 1,000 ~ 12,000rpm.

The stirring may be performed intermittently.

The external additive may include at least one selected from the group consisting of titanium oxide, large particle silica, small particle silica, polymer beads, and barium titanate.

The manufacturing method of the toner may further comprise sieving the external toner.

According to the manufacturing method of the toner using the external device according to the embodiment of the present invention, the adhesion strength of the external additive to the toner base particles is increased so that the external additive does not fall off from the surface of the toner base particles. As a result, a toner excellent in the amount of frictional charge and fluidity and high adhesion strength of the external additive can be obtained.

1 is a cross-sectional view of the external device according to an embodiment of the present invention.
FIG. 2 is a plan view of the stirrer provided in the external device of FIG. 1.
3 is a cross-sectional view of the external device according to another embodiment of the present invention.
Figure 4 is a cross-sectional view of the external device according to the prior art.

Hereinafter, with reference to the drawings will be described in detail the external device according to an embodiment of the present invention.

1 is a cross-sectional view of the external device 100 according to an embodiment of the present invention, Figure 2 is a plan view of the stirrer 120 provided in the external device 100 of FIG.

1 and 2, the external device 100 includes a vessel 110 and an agitator 120.

The container 110 is a place into which toner components (for example, toner base particles and external additives) are put. Toner components are mixed in the container 110 to form the external toner. As used herein, the term "external toner" refers to a toner including toner base particles and an external additive attached thereto.

The container 110 includes a bottom portion B and a ceiling portion T.

The bottom portion B may be closed.

The container 110 may be, for example, in the form of an open top, in which case the ceiling T may be an open space.

The container 110 may be, for example, in a form at least partially sealed at the top, in which case the ceiling T may be a lid (not shown) having an agitator coupler and optionally a toner component inlet.

The stirrer 120 is disposed in the container 110 and serves to agitate the toner component. The stirrer 120 includes a rotating shaft 121, the first stirring blade 122 and the second stirring blade 123.

The rotating shaft 121 may be disposed to extend from the ceiling portion T toward the bottom portion B. As the rotary shaft 121 rotates, the first stirring blade 122 and the second stirring blade 123 are rotated, whereby the toner components are mixed.

The first stirring blade 122 is coupled to the bottom portion (B) side of the rotation shaft 121, the second stirring blade 123 is coupled to the ceiling (T) side of the rotation shaft 121.

The ratio of the diameter of the second stirring blade 123 to the diameter of the first stirring blade 122 may be 1/4 to 3/1 (for example, 1/4 to 1/1). However, the present invention is not limited thereto, and the diameter of the first stirring blade 122 and the diameter of the second stirring blade 123 may be appropriately adjusted according to the capacity of the external device 100.

The diameter of the second stirring blade 123 may not be larger than the diameter of the first stirring blade 122. 1 illustrates only the case where the diameter of the second stirring blade 123 is smaller than the diameter of the first stirring blade 122, but the diameter of the second stirring blade 123 is equal to the diameter of the first stirring blade 122. It may be the same. As such, when the diameter of the second stirring blade 123 is not larger than the diameter of the first stirring blade 122, the adhesion strength of the external additive to the toner base particles is better than otherwise (hereinafter, simply the adhesion strength of the external additive). External toner can be obtained. In the present specification, "a diameter of the stirring blade" means the maximum length of the stirring blade, the rotation axis is the center of the stirring blade, the distance from the rotation axis to one end of the stirring blade is the radius of the stirring blade.

The first stirring blade 122 and the second stirring blade 123 may be coupled to the rotary shaft 121 in a direction crossing the longitudinal direction of the rotary shaft 121. For example, the first stirring blade 122 and the second stirring blade 123 may be coupled to the rotation shaft 121 in a direction orthogonal to the longitudinal direction of the rotation shaft 121.

Both longitudinal ends of the first stirring blade 122 may be curved toward the ceiling portion T, and both longitudinal ends of the second stirring blade 123 may be curved toward the bottom portion B. As shown in FIG. Specifically, the first stirring blade 122 may include a flat portion 122a coupled to the rotating shaft 121 and two bent portions 122b respectively positioned at both ends thereof in the longitudinal direction thereof. Similarly, the second stirring blade 123 may include a flat portion 123a coupled to the rotation shaft 121 and two bent portions 123b respectively positioned at both ends thereof in the longitudinal direction thereof. The bent portion 122b may be bent toward the ceiling portion T, and the bent portion 123b may be bent toward the bottom portion T. By providing the bent portions 122b and 123b having such a shape, the toner components can be mixed better than otherwise, so that an external toner having an increased adhesive strength of the external additive can be obtained.

3 is a cross-sectional view of the external device 200 according to another embodiment of the present invention.

Referring to FIG. 3, the external device 200 includes a vessel 210 having a bottom portion B and a ceiling portion T, and an agitator 220 disposed in the vessel 210. ) Is a rotary shaft 221 arranged to extend from the ceiling (T) toward the bottom portion (B), the first stirring blade 222 coupled to the bottom portion (B) side of the rotary shaft 221 and the rotary shaft 221 The second stirring blade 223 coupled to the ceiling (B) side of the.

The first stirring blade 222 may include a flat portion 222a coupled to the rotating shaft 221 and two bent portions 222b respectively positioned at both ends thereof in the longitudinal direction thereof. Similarly, the second stirring blade 223 may include a flat portion 223a coupled to the rotating shaft 221 and two bent portions 223b respectively positioned at both ends thereof in the longitudinal direction thereof.

The external device 200 of FIG. 3 differs from the external device 100 of FIG. 1 in that the diameter of the second stirring blade 223 is larger than the diameter of the first stirring blade 222.

1 to 3, although only the external device having two stirring blades is shown, the present invention is not limited thereto, and the external device according to another embodiment of the present invention may include three or more stirring blades. It may be.

4 is a cross-sectional view of the external device 300 according to the prior art.

Referring to FIG. 4, the external device 300 includes a vessel 310 having a bottom portion B and a ceiling portion T, and an agitator 320 disposed in the vessel 310, which includes an agitator 320. ) Includes a rotating shaft 321 disposed to extend from the ceiling portion T toward the bottom portion B, and a first stirring blade 322 coupled to the bottom portion B side of the rotating shaft 321.

The first stirring blade 322 may include a flat portion 322a coupled to the rotating shaft 321 and two bent portions 322b positioned at both ends thereof in the longitudinal direction thereof.

The external device 300 of FIG. 4 differs from the external device 100 of FIG. 1 in that it does not have a second stirring blade.

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

The toner manufacturing method according to an embodiment of the present invention includes the steps of preparing the external toner by adding the toner mother particles and the external additive to the external device, followed by stirring with the aforementioned agitator.

The toner base particles may include at least a binder resin, a colorant, and a wax. The toner base particles may further contain an additive such as a charge control agent. Such toner base particles may be prepared by any method known in the art, such as a pulverization method, suspension polymerization method, emulsion aggregation method, chemical milling method or dispersion polymerization method. For example, the toner base particles may be prepared by the method disclosed in Korean Patent Publication No. 2010-0048071 or No. 2010-0115148. The disclosures of Korean Patent Publication Nos. 2010-0048071 and 2010-0115148 are incorporated herein by reference.

The particle size of the toner base particles may be 6 ~ 12㎛. When the particle diameter of the toner base particles is within the above range, a toner image having excellent resolution can be obtained.

The external additive may include at least one selected from the group consisting of titanium oxide, large particle silica, small particle silica, polymer beads, and barium titanate.

The particle size of the external additive may be 5 ~ 200nm. When the particle size of the external additive is within the above range, a toner excellent in adhesion strength to the toner base particles can be obtained.

The amount of the external additive may be 0.1 to 4.0 parts by weight based on 100 parts by weight of the toner base particles. When the content of the external additive is within the range with respect to 100 parts by weight of the toner base particles, the adhesion strength of the external additive to the toner base particles may be high and excellent image quality may be realized.

The stirring may be performed for a stirring time of 1 to 30 minutes at a stirring speed of 1,000 ~ 12,000rpm. When the stirring speed and the stirring time are each within the above ranges, the adhesion strength of the external additive to the toner base particles can be increased.

The stirring may be performed intermittently. That is, the agitation may be performed by repeating the stopping / restirring cycle 1 to 4 times after the predetermined time passes after the start of the agitation within the stirring time. By performing the stirring in this way, the adhesion strength of the external additive can be further increased.

The manufacturing method of the toner may further comprise sieving the external toner. By the sieving step, it is possible to obtain an external toner having a particle size of 6 ~ 40㎛.

Another embodiment of the present invention provides a toner prepared by the above-described method for producing a toner.

The toner may have an appropriate level of charging characteristics (ie, a triboelectric charge amount) and fluidity, but may increase the adhesion strength of the external additive, thereby improving durability.

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

Example

Manufacturing example  1: for core Binder resin  Dispersions and For Shell Binder resin  Preparation of dispersion

A 30-liter reactor, combined with a stirrer, thermometer, and condenser, was combined into the oil bath. 6,600 g and 32 g of distilled water and surfactant (Dowfax 2A1) were added to the reactor thus combined to increase the reactor temperature to 70 ° C. and stirred at a stirring speed of 100 rpm. Thereafter, the monomer, that is, 8,380 g of styrene, 3,220 g of butyl acrylate, 370 g of 2-carboxyethyl acrylate, 226 g of 1,10-decanediol diacrylate, 5,075 g of distilled water, 226 g of a surfactant (Dowfax 2A1) 530 g of polyethylene glycol ethyl ether methacrylate and 188 g of 1-dodecanethiol as a chain transfer agent were stirred with a disk type impeller at 400 to 500 rpm for 30 minutes, and then slowly introduced into the reactor for 1 hour. Then, the reaction was performed for about 8 hours and then slowly cooled to room temperature to complete the reaction.

After completion of the reaction, the glass transition temperature (Tg) of the binder resin was measured using a differential scanning calorimeter (DSC), and the temperature was 62 ° C. In addition, the number average molecular weight of the binder resin was measured by gel permeation chromatography (GPC) using a polystyrene reference sample. As a result, the number average molecular weight was 50,000.

Manufacturing example  2: Preparation of colorant dispersion

540 g of cyan pigment (ECB303, manufactured by Daeil Jeonghwa Co., Ltd.), 27 g of surfactant (Dowfax 2A1) and 2,450 g of distilled water were added to a reactor with a volume of 5 liters combined with a stirrer, a thermometer, and a condenser. Was performed. After performing the preliminary dispersion for 10 hours, it was dispersed for 4 hours using a bead mill (Zeta RS, Netzsch, Germany). As a result, a colorant dispersion was obtained.

After completion of the dispersion, the particle size of the cyan pigment particles was measured using Multisizer 2000 (manufactured by Malvern), and the D50 (v) was found to be 170 nm. Here, D50 (v) means a particle size corresponding to 50% based on the volume average particle diameter, that is, particle size corresponding to 50% of the total volume when accumulating volume from small particles by measuring the particle diameter.

Manufacturing example  3: Preparation of wax dispersion

After adding 65 g of surfactant (Dowfax 2A1) and 1,935 g of distilled water to a volume 5 liter reactor in which a stirrer, a thermometer, and a condenser were combined, the mixture was slowly stirred at 95 ° C. for about 2 hours, and then wax (P. 1,000 g was charged to the reactor. The mixed solution was dispersed for 30 minutes using a pressure discharge type homogenizer (Nihon Precision Machinery). As a result, a wax dispersion was obtained.

After completion of the dispersion, the particle size of the dispersed wax particles was measured using Multisizer 2000 (manufactured by Malvern), and the D50 (v) was found to be 200 nm.

Manufacturing example  4: Toner Parent particle  Produce

13,881 g of the binder resin dispersion prepared above, 2,238 g of the colorant dispersion, and 2,873 g of the wax dispersion were added to a 70-liter reactor, followed by mixing at 25 ° C. for 15 minutes at a stirring speed of 1.21 m / sec. To this, 5,760 g of a mixed solution of PSI (Poly Silicato Iron) and an aqueous solution of nitric acid (concentration = 1.88% by weight) (PSI / aqueous solution of nitric acid = 1/2 (weight ratio)) was added, and a homogenizer (IKA, T-50) was used to stir the reactor contents at 25 ° C. at a stirring speed of 50 rpm (stirring line speed: 1.79 m / sec) for 30 minutes, and the homogenization process was performed. At this time, the pH of the contents of the reactor was 1.6. Thereafter, the temperature of the reactor was increased to 51 ° C., followed by stirring at 2.42 m / sec to continue coagulation until the D50 (v) of the toner base particles became 6.4 μm, and then 5,398 g of the binder resin dispersion for shell was added to about 20 Injected over minutes. Subsequently, stirring was continued until the average particle diameter of the toner base particles became 7.0 μm, and then 4 wt% aqueous sodium hydroxide solution was added to the reactor and stirred at 1.90 m / sec until the pH was 4, and the pH was 7 It stirred at 1.55 m / sec until it became this. Thereafter, the temperature of the reactor was raised to 96 ° C. while maintaining the stirring speed so that the toner base particles were united. Then, when the circularity was measured using FPIA-3000 (manufactured by Sysmex, Japan), when the measured circularity was 0.980, the temperature of the reactor was cooled to 40 ° C, and the pH of the reactor was adjusted to 9.0. The toner base particles were separated by using a nylon mesh (pore size: 16 μm), and the separated toner base particles were washed four times with distilled water, and then a pH of 1.88% by weight of nitric acid solution was mixed with distilled water. After washing again with a mixture of 1.5, and then washed again with distilled water four times to remove all the surfactant and the like. Thereafter, the washed toner base particles were dried in a fluidized bed dryer at a temperature of 40 ° C. for 5 hours to obtain dried toner base particles.

Example  1 to 3 and Comparative example  One

100 parts by weight of the toner base particles prepared in Preparation Example 4, 1.0 part by weight of R8200 (manufactured by Aerosil), which is a small particle silica, and RY50, which is a large particle silica, in each of the two-liter external attachment devices (self-made) shown in Table 1 below. (Aerosil) 1.5 parts by weight and 0.3 parts by weight of titanium oxide, JMT-150FI (manufactured by TAYCA), were prepared to obtain a mixture, and then the mixture was stirred at room temperature (25 ° C) at a speed of 8000 rpm to obtain an external toner. The agitation was carried out by repeating the suspension (10 seconds) / stirring (5 minutes) cycle twice after the initial 5 minutes stirring. Thereafter, the external toner was sieved with a sieve having a mesh size of 45 μm.

External device Example 1 1 (diameter of the first wing: 150mm, diameter of the second wing: 50mm) Example 2 Not shown (diameter of first wing: 150 mm, diameter of second wing: 150 mm) Example 3 3 (diameter of the first wing: 50mm, diameter of the second wing: 150mm) Comparative Example 1 4 (diameter of the first wing: 150 mm)

Evaluation example

For each of the external toners prepared in Examples 1 to 3 and Comparative Example 1, the frictional charge amount, fluidity, and adhesive strength of the external additive were evaluated as follows, and the results are shown in Table 2 below.

Evaluation of triboelectric charge amount

The triboelectric charge amount of the external toner was measured using a q / m meter (Epping, Germany). 0.7 g of the external toner prepared in each of Examples and Comparative Examples and 9.3 g of a carrier (100 µm, Japan Society of Image Sciences) were added to a 100 mL bottle, and then left for 15 hours under NN conditions (20 ° C., RH 40%). It was. Subsequently, the mixture was mixed at 96 rpm for 5 minutes using a Turbula mixer (WAB, Switzerland). After mixing, 1.0g of the sample was put in a measuring cell of q / m meter and the charge amount was measured by blow-off under the conditions of 20ml / min and 100 voltage.

liquidity( cohesiveness ) evaluation

The fluidity of the external toner was measured using a powder tester (manufactured by Hosokawa micron). Three sieves were used to measure fluidity, and the mesh sizes of each sieve were 53 μm, 45 μm, and 38 μm. The three sieves were stacked in the order of 38 μm sheaves, 45 μm sheaves and 53 μm sheaves from bottom to top. At the first measurement, 2 g of the external toner was weighed and placed on a 53 μm sieve to give a vibration of the dial 3 for 40 seconds. When the vibration for 40 seconds was completed, the weight of each of the three sieves was measured to determine the amount of external toner remaining on each sieve. After the measurement, the fluidity was calculated by the following Equation 1.

[Equation 1]

% Fluidity = {(weight of powder remaining on the upper sieve (53 μm mesh)) / 2} × 100 × (1/5) + {(weight of powder remaining on the middle sheave (45 μm mesh) ) / 2} × 100 × (3/5) + {(weight of powder remaining on lower sheave (38 μm mesh)) / 2} × 100 × (1/5)

External  Bond strength evaluation

The adhesion strength of the external additive was evaluated by comparing it with an external toner sample not exposed to ultrasonic waves and a sample that was exposed to ultrasonic waves to artificially destabilize the attachment of the external additives.

First, 4 g of the external toner was dispersed in 200 mL of a 0.15% by weight surfactant solution obtained by adding surfactant (Dowfax 2A1) to deionized water to obtain a dispersion. The dispersion was then exposed to ultrasonic waves while stirring in an ultrasonic bath (Brasonic B8510) at 250 rpm for 30 minutes. The dispersion exposed to ultrasonic waves was filtered while washing with 400 mL of a 0.15 wt% surfactant solution obtained by adding a surfactant (Dowfax 2A1) to deionized water and a vacuum filter. The toner on the filter paper was then collected and dried in a vacuum oven for 12 hours. Thereafter, 3 g of the ultrasonically treated external toner was added to a press mold having a diameter of 3 cm, and then pressed for 20 minutes under conditions of 40 ° C. and 20 MPa to obtain a flat pellet toner sample. Next, the pellet-shaped toner sample obtained above was analyzed by XRF (Philips, MagiX) to measure the intensities of Si and Ti, and then the contents of silica and titanium oxide were determined by comparing the intensity with the standard intensity. The percentage (Wm / Wi × 100) of the content (Wm / Wi × 100) of the content (Wm) of the external additive measured by the XRF analysis on the content (Wi) of the external additive before the ultrasonic treatment was calculated and recorded as the adhesion strength of the external additive.

Triboelectric charge amount
(uC / g) liquidity(%) Bond strength of external additives (%) Example 1 -37.1 7.2 97 Example 2 -36.0 7.4 95 Example 3 -36.0 7.5 90 Comparative Example 1 -36.2 7.5 86

Referring to Table 2, the external toner prepared in Examples 1 to 3 was found to have a higher adhesive strength than the external toner prepared in Comparative Example 1. In addition, the external toner prepared in Examples 1 to 3 was found to have a frictional charge amount and fluidity similar to that of the external toner prepared in Comparative Example 1.

Although the present invention has been described with reference to the drawings and embodiments, it is to be understood that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100, 200, 300: external device 110, 210, 310: container
120, 220, 320: Stirrers 121, 221, 321: Rotating shaft
122, 123, 222, 223, 322: stirring blade
122a, 123a, 222a, 223a, 322a: flat part
122b, 123b, 222b, 223b, 322b: bend

Claims (9)

A container having a bottom and a ceiling; And
A stirrer disposed in the vessel,
The stirrer includes a rotating shaft disposed to extend from the ceiling side toward the bottom portion, a first stirring blade coupled to the bottom side of the rotating shaft, and a second stirring blade coupled to the ceiling side of the rotating shaft. The method of claim 1,
The ratio of the diameter of the second stirring blade to the diameter of the first stirring blade is an external attachment device of 1/4 ~ 3/1. The method of claim 1,
And the diameter of the second stirring blade is not greater than the diameter of the first stirring blade. The method of claim 1,
And both longitudinal ends of the first stirring blade are bent toward the ceiling portion, and both longitudinal ends of the second stirring blade are bent toward the bottom portion. A toner manufacturing method comprising the steps of preparing an external toner by adding a toner mother particle and an external additive to an external device according to any one of claims 1 to 4, and then stirring the same with the stirrer. The method of claim 5,
The amount of the external additive is 0.1 to 4.0 parts by weight based on 100 parts by weight of the toner base particles. The method of claim 5,
A particle size of the toner base particles is 6 to 12 탆, and a particle size of the external additive is 5 to 200 nm. The method of claim 5,
The stirring is performed for 1 to 30 minutes at a speed of 1,000 ~ 12,000rpm. 9. The method of claim 8,
And the stirring is performed intermittently.

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