KR20150080340A - Toner and method of preparing the same - Google Patents

Abstract

Disclosed are a toner and a manufacturing method thereof. The disclosed toner comprises: a core unit including a first binder resin having a weight average molecular weight of Mw_1; a first shell unit including a second binder resin having a weight average molecular weight of Mw_2 and surrounding the core unit; and a second shell unit including a third binder resin having a weight average molecular weight of Mw_3 and surrounding the first shell unit wherein the Mw_1, the Mw_2 and the Mw_3 satisfy a formula (Mw_2 < Mw_1 < Mw_3).

Description

Toner and method of preparing same

A toner and a manufacturing method thereof are disclosed. More particularly, the present invention relates to a toner having a triple structure which is excellent in both fixing property, strength and durability, and a process for producing the same.

Generally, the toner is prepared by adding a coloring agent, wax, or the like to a thermoplastic resin serving as a binder resin. It is also possible to use a charge control agent which imparts chargeability to the toner and keeps it, a release agent such as a wax for releasing the toner from the fixing portion of the image forming apparatus, a toner for improving fluidity and developability, Can be added to the toner. 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, an emulsion aggregation method, a chemical milling method, and a dispersion polymerization method.

Among them, the emulsion aggregation method (see U.S. Patent No. 5,916,725, No. 6,268,103, etc.) includes a step of preparing a fine emulsion resin particle composition through emulsion polymerization, and a step of coagulating the composition with a colorant etc. in a separate dispersion do. This method has an advantage in that it can solve problems such as a high cost and a wide particle size distribution in the pulverization method, and can make the toner particles spherical by controlling the coagulation condition.

However, the toner particles produced by the conventional emulsion agglomeration method have a problem that they can not have excellent fixing property, strength and durability at the same time.

An embodiment of the present invention provides a triple structure toner which is excellent in both fixing property, strength and durability.

Another embodiment of the present invention provides a method of producing the toner.

According to an aspect of the present invention,

A core portion comprising a first binder resin having a weight average molecular weight of Mw &_lt; _{1 &} gt ;;

A second binder resin having a weight average molecular weight of Mw &lt; _{2 &} gt ;; a first shell portion surrounding the core portion; And

A third binder resin having a weight average molecular weight of Mw &lt; _{3 &} gt ;, and a second shell portion surrounding the first shell portion,

Wherein at least one portion selected from the group consisting of the core portion, the first shell portion and the second shell portion further comprises at least one of a colorant and wax,

Mw ₁ , Mw ₂ and Mw ₃ satisfy the formula (Mw ₂ <Mw ₁ <Mw ₃ ).

Wherein the weight average molecular weight of the first binder resin (Mw ₁₎ is 42,000 ~ 55,000, and wherein the weight average molecular weight of the second binder resin (Mw ₂₎ is 24,000 ~ 45,000, and a weight average molecular weight of said third binder resin (Mw ₃ ) May be between 55,000 and 79,000.

The toner may include 70 to 90 parts by weight of the first binder resin, 5 to 25 parts by weight of the second binder resin, and 1 to 6 parts by weight of the third binder resin.

According to another aspect of the present invention,

(S10) of adding a first binder resin dispersion liquid and a coagulant to a reactor, and then firstly raising the contents of the reactor to form a toner core portion;

(S20) forming a first shell portion surrounding the toner core portion by further adding a second binder resin dispersion to the reactor contents containing the toner core portion;

(S30) forming a second shell portion surrounding the first shell portion by further adding a third binder resin dispersion to the reactor contents containing the first shell portion; And

And a step (S40) of obtaining the combined toner particles by secondarily raising the contents of the reactor through the second shell part forming step,

At least one of the colorant dispersion and the wax dispersion is further added to the reactor in at least one of steps (S10) and (S20)

The weight average molecular weight (Mw ₁ ) of the first binder resin contained in the first binder resin dispersion, the weight average molecular weight (Mw ₂ ) of the second binder resin contained in the second binder resin dispersion, a first weight average molecular weight of the binder resin contained in the 3 (Mw ₃₎ provides a method for producing a toner satisfying the expression _{(Mw 2 <Mw 1 <Mw} 3).

Manufacturing method of the toner is, in the step (S10), In the place of the first binder resin dispersion liquid in the reactor with the second binder resin dispersion and the second binder resin dispersion liquid, and in this case, the Mw ₁ is And Mw ₂ and Mw ₃ according to the ratio of the amounts of the third binder resin and the third binder resin in the second binder resin and the third binder resin in the second binder resin dispersion.

The primary temperature increase may be performed at a temperature 2 to 20 ° C lower than the glass transition temperature of the first binder resin injected into the core portion forming step.

The secondary heating may be performed at a temperature 10-40 ° C higher than the glass transition temperature of the third binder resin added to the second shell forming step.

The content of the first binder resin added to the core forming step (S10), the content of the second binder resin added to the first shell forming step (S20), and the second shell forming step (S30) The content of the third binder resin added may be 70 to 90 parts by weight, 5 to 25 parts by weight and 1 to 6 parts by weight, respectively.

According to the method for producing a toner according to an embodiment of the present invention, it is possible to obtain a toner excellent in fixing property, strength and durability.

1 is a schematic view of a toner according to an embodiment of the present invention.
FIG. 2 is a graph showing changes in storage elastic modulus according to the temperature of the toner prepared in Example 1 and Comparative Example 1. FIG.
3 is a graph showing changes in loss elastic modulus according to the temperature of the toner prepared in Example 1 and Comparative Example 1. FIG.
4 is a graph showing changes in storage elastic modulus according to the frequency of the toner prepared in Example 1 and Comparative Example 1. FIG.
FIG. 5 is a graph showing changes in loss elastic modulus according to the frequency of the toner prepared in Example 1 and Comparative Example 1. FIG.
6 is a stress-strain curve of the toner prepared in Example 1. Fig.
7 is a stress-strain curve of the toner prepared in Comparative Example 1. Fig.

Hereinafter, a toner according to an embodiment of the present invention and a method for producing the same will be described in detail.

The toner according to an embodiment of the present invention includes a core portion including a first binder resin having a weight average molecular weight of Mw ₁ , and a second binder resin having a weight average molecular weight of Mw ₂ , wherein the first shell portion And a third binder resin having a weight average molecular weight of Mw ₃ , and a second shell portion surrounding the first shell portion. As used herein, the term &quot; toner &quot; may refer to one toner particle according to the context, and may refer to a collection of toner particles (i.e., toner powder).

At least one portion selected from the group consisting of the core portion, the first shell portion and the second shell portion further comprises at least one of a colorant and wax.

Mw ₁ , Mw ₂ and Mw ₃ may satisfy the following formula:

Mw ₂ < Mw ₁ < Mw ₃ .

The toner may have an appropriate level of glass transition temperature because the Mw ₁ in the core portion occupying the largest amount of the toner is larger than the Mw ₂ and smaller than the Mw ₃ .

Since the Mw ₂ in the first shell portion is small, the toner may have excellent fixing properties (i.e., thermal characteristics).

Since the Mw ₃ in the second shell portion is large, the toner may have excellent thermal strength, mechanical strength and durability. Thus, the storage stability of the toner can be improved by preventing the phenomenon of caking, which is a phenomenon in which the toner melts and fuses to each other even if the toner is stored for a long time under a high temperature environment.

The second shell part may have a thin film form to prevent the fixing property of the toner from deteriorating.

By satisfying the above expressions Mw ₁ , Mw ₂ and Mw ₃ (Mw ₂ <Mw ₁ <Mw ₃ ), the thermal stability, mechanical strength and durability of the toner can be maintained at an appropriate level while maintaining the glass transition temperature of the entire toner at an appropriate level . As a result, both the fixing property and the strength of the toner in a trade-off relationship with each other can be improved.

The first binder resin may have a weight average molecular weight (Mw ₁ ) of 42,000 to 55,000, the second binder resin may have a weight average molecular weight (Mw ₂ ) of 24,000 to 45,000, The molecular weight (Mw ₃ ) may be from 55,000 to 79,000.

The toner may include 70 to 90 parts by weight of the first binder resin, 5 to 25 parts by weight of the second binder resin, and 1 to 6 parts by weight of the third binder resin. Here, the total content of the first binder resin, the second binder resin and the third binder resin is 100 parts by weight. When the content ratio of each of the above-mentioned binder resins is within the above-mentioned range, the strength and durability of the toner can be improved while the fixing property of the toner is kept high.

Hereinafter, the structure of the above-described toner will be described in more detail with reference to Fig.

1 is a schematic diagram of a toner 10 according to an embodiment of the present invention.

1, the toner 10 includes a core portion 11, a first shell portion 12 surrounding the core portion 11, and a second shell portion 13 surrounding the first shell portion 12 .

The second binder resin (not shown) is distributed to the first shell part 12 and the third binder resin (not shown) is distributed to the second shell part 13, Resin (not shown) is distributed.

At least one of a colorant (not shown) and wax (not shown) may be further distributed to at least one portion selected from the group consisting of the core portion 11, the first shell portion 12 and the second shell portion 13. [

An external additive (not shown) may be further distributed on the surface of the second shell portion 13.

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

The method of manufacturing a toner according to the present invention includes the steps of (S10) forming a toner core portion by first raising the contents of a reactor after charging a first binder resin dispersion liquid and a coagulant into a reactor, (S20) of forming a first shell part surrounding the toner core part by further adding a dispersion liquid to the first shell part, and further adding a third binder resin dispersion to the reactor contents containing the first shell part to form a second shell surrounding the first shell part (S30) of forming the second shell portion, and a step (S40) of obtaining the coalesced toner particles by secondarily raising the reactor contents through the second shell portion forming step. Each of the above steps may be performed in one reactor, but the present invention is not limited thereto. One or more of the four steps and two or more steps may be performed in two or more reactors.

At least one of the colorant dispersion and the wax dispersion may be added to the reactor in at least one of the steps (S10) and (S20).

The weight average molecular weight (Mw ₁ ) of the first binder resin contained in the first binder resin dispersion, the weight average molecular weight (Mw ₂ ) of the second binder resin contained in the second binder resin dispersion, The weight average molecular weight (Mw ₃ ) of the third binder resin contained in the second binder resin satisfies the following formula:

Mw ₂ < Mw ₁ < Mw ₃ .

In the step (S10), the second binder resin dispersion liquid and the second binder resin dispersion liquid are put into the reactor together with a predetermined ratio in place of the first binder resin dispersion, and in this case, Mw ₁ is the second binder Mw ₂ and Mw ₃ may be a value obtained by weighted averaging of the Mw ₂ and the Mw ₃ in accordance with the input ratio of the second binder resin in the resin dispersion and the third binder resin in the third binder resin dispersion.

The reactor may comprise a stirrer, a heating means (e.g. a heater), a pressurizing means and / or a depressurizing means (e. G., A vacuum line and a vacuum pump).

In one embodiment, the binder resin dispersion, the colorant dispersion, and the wax dispersion may be the same or similar to the latex dispersion, colorant dispersion, and wax dispersion described in Korean Patent Publication No. 2010-0048071. Korean Patent Publication No. 2010-0048071 is incorporated herein by reference.

In another embodiment, the binder resin dispersion, the colorant dispersion, and the wax dispersion may be the same or similar to the polyester resin dispersion, colorant dispersion, and wax dispersion disclosed in Korean Patent Publication No. 2010-0115148 . Korean Patent Publication No. 2010-0115148 is incorporated herein by reference in its entirety.

The first binder resin may have a glass transition temperature of 54 to 60 ° C, the second binder resin may have a glass transition temperature of 54 to 58 ° C, and the third binder resin may have a glass transition temperature of 56 to 65 ° C. Lt; / RTI &gt; When the glass transition temperature of each of the binder resins is within the above range, the toner formed using the binder resin particles is excellent in fixing property.

The colorant to be used in the preparation of the colorant dispersion may be black pigments, cyan pigments, magenta pigments, yellow pigments, and mixtures thereof, which are pigments commonly used commercially.

The total amount of the colorant added to the step (S10) and the step (S20) may be 3 to 20 parts by weight based on 100 parts by weight of the total amount of the first, second and third binder resins.

The wax used in the preparation of the wax dispersion may be a known wax. 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 wax; And an ester-based wax. The wax may be used alone or in combination of two or more.

In addition, the wax may include at least one of a paraffin wax and a polyester wax. The paraffin wax mainly contains C ₂₀ to C ₃₆ linear saturated hydrocarbons, and may have a weight average molecular weight of 30 to 500 and a melting point of 40 to 80 ° C.

The wax may be a mixed wax of the paraffin wax and the polyester wax, for example, HNP-9 or HNP-11 wax.

The total amount of the wax added to the step (S10) and the step (S20) may be 5 to 20 parts by weight based on 100 parts by weight of the total amount of the first, second and third binder resins.

The coagulant may be added not only to the core forming step (S10) but also to the first shell forming step (S20) and / or the second shell forming step (S30). As such coagulant, Fe-polysilicate such as NaCl, KCl, or PSI (Poly Silicato Iron) may be used.

The total amount of the flocculant added to the step (S10), the step (S20) and the step (S30) is preferably at most about 100 parts by weight based on 100 parts by weight of the total amount of the first binder resin, the second binder resin and the third binder resin 5 to 40 parts by weight.

The primary temperature increase may be 2 to 20 ° C lower than the glass transition temperature (Tg ₁ ) of the first binder resin injected into the core portion forming step. The temperature during the first temperature increase the range _{(Tg 1 - 2 ~ 20 ℃} ) is within, causing a flocculation picked by each particle.

The step (S10) (that is, the coagulation step by the first temperature increase) may proceed until the particle size of the toner becomes 5.0 to 6.0 mu m.

The secondary heating may be performed at a temperature 10 to 40 ° C higher than the glass transition temperature (Tg ₃ ) of the third binder resin added to the second shell forming step. If the temperature at the time of the second heating is within the above range (Tg ₃ + 10 to 40 ° C), it is possible to prevent the wax masses from sticking together to form a wax mass, and then protruding the wax mass to the toner surface.

The step (S40) (i.e., the step of coalescing by the second heating) may proceed until the particle diameter of the toner becomes 6.6 to 7.2 mu m, whereby toner particles having substantially uniform particle size and shape can be obtained.

Each of the binder resins used in the above steps may be the same kind of binder resin.

The content of the first binder resin added to the core forming step (S10), the content of the second binder resin added to the first shell forming step (S20), and the second shell forming step (S30) The content of the third binder resin added may be 70 to 90 parts by weight, 5 to 25 parts by weight and 1 to 6 parts by weight, respectively. When the content ratio of the binder resin used in each of the above steps is within the above-mentioned range, a toner excellent in fixing property and excellent in toner strength and durability can be obtained.

The method of manufacturing the toner may further include washing and drying the toner particles obtained in the combining step with water. First, the reactor contents containing the toner particles are cooled to room temperature, filtered, the filtrate is removed, and the toner particles are washed with water. Pure water having a conductivity of 10 uS / cm or less may be used for the washing, and the washing may be continued until the conductivity of the filtered filtrate becomes 50 uS / cm or less. Cleaning of the toner with pure water may proceed batchwise or continuously. Cleaning of the toner using pure water can be performed to remove unnecessary components other than toner components 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 can be dried by using a fluid bed dryer, a flash jet dryer or the like. Further, a desired external additive can be added to the toner obtained by drying. The external additive is for improving the fluidity of the toner or controlling the charging property. Examples of the external additive include large diameter silica (particle diameter:? 40 nm), small particle size silica (7 nm? Particle diameter? 30 nm), polymer beads, Mixtures may be used.

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

Example

Manufacturing example  1-1: Binder resin  Preparation of Dispersion (A)

A reactor having a volume of 30 liters equipped with a stirrer, a thermometer and a condenser was installed in an oil bath. 6,600 g and 32 g of distilled water and a surfactant (Dowfax 2A1) were charged into the thus-installed reactor, respectively, and the temperature of the reactor was increased 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 450 rpm for 30 minutes, and then slowly added to the reactor for 1 hour. Thereafter, the reaction was allowed to proceed for about 8 hours and then slowly cooled to room temperature (25 ° C) to complete the reaction. As a result, a binder resin was obtained.

After completion of the reaction, the glass transition temperature (Tg) of the binder resin obtained above was measured using a differential scanning calorimeter (DSC), and as a result, the temperature was 57 ° C. The weight average molecular weight of the binder resin was measured by GPC (gel permeation chromatography) using a polystyrene standard sample, and the weight average molecular weight was 45,000.

Manufacturing example  1-2: Binder resin  Preparation of Dispersion (B)

9,700 g of styrene, 1,916 g of butyl acrylate, 370 g of 2-carboxyethyl acrylate and 226 g of 1,10-decanediol diacrylate, 5,075 g of distilled water, 226 g of a surfactant (Dowfax 2A1), 20 g of polyethylene glycol ethyl ether A binder resin dispersion (B) was prepared in the same manner as in Production Example 1-1 except that 530 g of acrylate and 188 g of 1-dodecanethiol were used as a chain transfer agent. The glass transition temperature (Tg) and weight average molecular weight of the binder resin measured by the same method as in Production Example 1-1 were 65 ° C and 70,000, respectively.

Manufacturing example  2: Preparation of colorant dispersion

540 g of cyan pigment (ECB303, manufactured by Dainippon Ink & Chemicals, Inc.), 27 g of a surfactant (Dowfax 2A1) and 2,450 g of distilled water were placed in a reactor having a volume of 5 liters equipped with a stirrer, a thermometer and a condenser, Respectively. 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, a particle size corresponding to 50% of the total volume when accumulating the volume from the small particle by measuring the particle diameter.

Manufacturing example  3: Preparation of wax dispersion

65 g of a surfactant (Dowfax 2A1) and 1,935 g of distilled water were put into a 5-liter reactor equipped with a stirrer, a thermometer and a condenser, and the mixture was stirred at 95 ° C for about 2 hours with stirring to obtain a wax (P- 778) were charged into 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.

Example  1: Preparation of toner particles of core-first shell-second shell structure

(Core part forming step)

The binder resin dispersion (A) prepared in Preparation Example 1-1, the binder resin dispersion (B) prepared in Production Example 1-2, the colorant dispersion prepared in Production Example 2, and the preparation Example 3 , And the mixture was stirred at 25 占 폚 for about 15 minutes at a stirring speed of 1.21 m / sec and mixed. A mixed solution (PSI / nitric acid aqueous solution = 1/2 (weight ratio)) of PSI (Poly Silcato Iron) and an aqueous nitric acid solution (concentration = 1.88 wt%) was added as a coagulant to the mixture and homogenized (IKA, 50) at 25 DEG C at a stirring rate of 10,000 rpm for 30 minutes. At this time, the pH of the contents of the reactor was 1.6. Thereafter, the temperature of the reactor was elevated to 53 캜 for the first time, and the mixture was stirred at 140 rpm to continue aggregation until the D50 (v) of the toner particles became 5.3 탆

(First cell formation step)

After the core portion forming step, the binder resin dispersion (A) prepared in Preparation Example 1-1 was added to the reactor over a period of 30 minutes. Thereafter, agitation was continued by stirring at a stirring speed of 120 rpm until the D50 (v) of the toner particles became 6.3 탆 while maintaining the temperature of the reactor at 53 캜.

(Second shell portion forming step)

After the first shell part forming step, the binder resin dispersion (B) prepared in Preparation Example 1-2 was added to the reactor over a period of 20 minutes. Subsequently, stirring was continued until the D50 (v) of the toner particles became 6.8 占 퐉 while maintaining the temperature of the reactor at 53 占 폚.

(Subsequent step)

After the second shell part formation step, a 4 wt% sodium hydroxide aqueous solution was added to the reactor, and the mixture was stirred at 115 rpm until the pH reached 4. When the pH was 7, the mixture was stirred at 100 rpm. Thereafter, the temperature of the reactor was elevated to 96 캜 while maintaining the stirring speed, so that the toner particles were allowed to coalesce. Thereafter, 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 contents was adjusted to 9.0 The separated toner particles were washed four times with distilled water and then mixed with an aqueous nitric acid solution of 1.88 wt% in distilled water to prepare a toner having a pH of 1.5 , And then washed with distilled water four times to remove all of the surfactant and the like. Thereafter, the washed toner particles were dried in a fluid bed drier at a temperature of 40 캜 for 5 hours to obtain dried toner particles.

Comparative Example  1: Preparation of toner particles of core-shell structure

(Core part forming step)

The binder resin dispersion (A) prepared in Preparation Example 1-1, the binder resin dispersion (B) prepared in Production Example 1-2, the colorant dispersion prepared in Production Example 2, and the preparation Example 3 , And the mixture was stirred at 25 占 폚 for about 15 minutes at a stirring speed of 1.21 m / sec and mixed. A mixed solution (PSI / nitric acid aqueous solution = 1/2 (weight ratio)) of PSI (Poly Silcato Iron) and an aqueous nitric acid solution (concentration = 1.88 wt%) was added as a coagulant to the mixture and homogenized (IKA, 50) at 25 DEG C at a stirring rate of 10,000 rpm for 30 minutes. At this time, the pH of the contents of the reactor was 1.6. Thereafter, the temperature of the reactor was elevated to 53 캜 for the first time, and the mixture was stirred at 140 rpm to continue aggregation until the D50 (v) of the toner particles became 5.3 탆

(Cell formation step)

After the core portion forming step, the binder resin dispersion (A) prepared in Preparation Example 1-1 and the binder resin dispersion (B) prepared in Production Example 1-2 were added to the reactor over 30 minutes. Thereafter, stirring was continued until the D50 (v) of the toner particles became 6.8 탆 while maintaining the temperature of the reactor at 53 캜.

(Subsequent step)

After the shell part formation step, a 4 wt% sodium hydroxide aqueous solution was added to the reactor, and the mixture was stirred at 115 rpm until the pH reached 4. The mixture was stirred at 100 rpm until the pH reached 7. Thereafter, the temperature of the reactor was elevated to 96 캜 while maintaining the stirring speed, so that the toner particles were allowed to coalesce. Thereafter, 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 contents was adjusted to 9.0 The separated toner particles were washed four times with distilled water and then mixed with an aqueous nitric acid solution of 1.88 wt% in distilled water to prepare a toner having a pH of 1.5 , And then washed with distilled water four times to remove all of the surfactant and the like. Thereafter, the washed toner particles were dried in a fluid bed drier at a temperature of 40 캜 for 5 hours to obtain dried toner particles.

The contents of the components used in Example 1 and Comparative Example 1, and the glass transition temperature and weight average molecular weight of the final binder resin are shown in Table 1 below. Here, the final binder resin may be a binder resin (A), a binder resin (B), or a mixture thereof (mixed at the ratios used in the respective Examples and Comparative Examples). When the final binder resin is a mixture of the binder resin (A) and the binder resin (B), a mixture of the binder resin dispersion (A) and the binder resin dispersion (B) is used in each of the above- To prepare a mixed binder resin dispersion, drying the mixed binder resin dispersion to obtain a dried mixed binder resin, and measuring a glass transition temperature of the dried mixed binder resin to measure the glass transition temperature of the final binder resin Transition temperature. When the final binder resin is a mixture of the binder resin (A) and the binder resin (B), the weight average molecular weight of the final binder resin depends on the mixing ratio of the binder resin (A) and the binder resin (B) The weight average molecular weight (45,000) of the binder resin (A) and the weight average molecular weight (70,000) of the binder resin (B) were weighted averages.

Binder resin dispersion
(A) (g) Binder resin dispersion
(B) (g) The glass transition temperature (캜) of the final binder resin The weight average molecular weight of the final binder resin Colorant dispersion
(g) Wax dispersion (g) Coagulant
(g) Example 1 Step of forming core part 7,690 690 58 47,058 670 860 3,820 The first shell part forming step 2,910 0 57 45,000 670 860 0 The second shell part forming step 0 270 65 70,000 0 0 0 Comparative Example 1 Step of forming core part 7,690 690 58 47,058 1,340 1,720 3,820 Shell part formation step 2,910 270 58 47,122 0 0 0

The toner particles Volume average particle diameter ( D50 (v)) measurement

Beckman everything between the multi (Beckman Coulter Inc.) low (Multisizer ™ 3 Coulter Counter ^® was determined using a volume average particle diameter (D50 (v)) of the toner particles. Ke in that between the multi-aperture (aperture) 100 (Dowfax 2A1) was added in an appropriate amount to 50-100 ml of ISOTON-II (Beckman Coulter Co.), which was an electrolytic solution, 10 to 15 mg of a test sample was added thereto and dispersed in an ultrasonic disperser for 5 minutes to prepare a sample .

Measurement of circularity of toner particles

The circularity of the toner particles was measured using FPIA-3000 (manufactured by Sysmex, Japan). In the roundness measurement using FPIA-3000, a measurement sample was prepared by adding a proper amount of a surfactant (Dowfax 2A1) to 50 to 100 ml of distilled water, adding 10 to 20 mg of toner particles thereto, and dispersing the dispersion in an ultrasonic disperser for 1 minute .

The circularity is automatically obtained from FPIA-3000 by the following equation (1).

[Equation 1]

Circularity = 2 占 (area 占 π) ^1/2 / perimeter

In the above equation, the area means the area of the projected toner, and the perimeter means the circumferential length of the projected toner. This value can have a value from 0 to 1, and the closer to 1, the more spherical.

Evaluation example

The fixing characteristics and the mechanical strength of the toner prepared in Example 1 and Comparative Example 1 were evaluated as follows, and the results are shown in Figs. 2 to 7, respectively.

(Evaluation of fixing property)

The change in the storage modulus and the change in the loss elastic modulus according to the temperature of each toner were measured using a rheometer (TA Instrument, ARES-G2), and the results are shown in Figs. 2 and 3, respectively. Here, toner powder was used as a measurement sample.

2 and 3, the toner prepared in Example 1 showed almost the same change in storage modulus and loss modulus as the toner prepared in Comparative Example 1 according to the temperature, It can be seen that the toner prepared in Comparative Example 1 has almost the same level of fixing properties as the toner prepared in Comparative Example 1. [

(Mechanical strength evaluation)

Dynamic measurement apparatus by using the (Hysitron, nanoDMA ^®) measuring a change in variation, and the loss elastic modulus of storage elastic modulus with respect to the frequency of each of the toner, respectively, are shown the results in Figs. Here, one toner particle was used as a measurement sample.

Referring to FIG. 4, the toner prepared in Example 1 has a larger increase in storage modulus than the toner prepared in Comparative Example 1, and has a storage elastic modulus equal to or greater at the same frequency.

Referring to FIG. 5, the toner prepared in Example 1 has a loss elastic modulus that is greater or equal to about 80 Hz at the same frequency as the toner prepared in Comparative Example 1, but has a loss elastic modulus at the same frequency at about 80 Hz or more appear.

In addition, using a dynamic measuring device (Hysitron, nanoDMA ^®) to measure the stress-strain curve (stress-strain curve) of each toner, it was respectively shown in Figs. 6 and 7 the results. Here, one strain curve was obtained per one toner particle. 6 is a view showing a stress deformation curve of each of the two toner particles selected in the toner prepared in Example 1. Fig. 7 is a view showing a stress deformation curve of each of the three toner particles selected in the toner prepared in Comparative Example 1 to be. 6 and 7, the slope of the curve means Young's modulus.

6 and 7, the toner prepared in Example 1 has a higher Young's modulus than the toner prepared in Comparative Example 1.

4 to 7, it can be seen that the toner prepared in Example 1 is superior in mechanical strength to the 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 suggested to those skilled in the art. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: Toner 11: Core part
12: first shell part 13: second shell part

Claims (8)

A core portion comprising a first binder resin having a weight average molecular weight of Mw &_lt; _{1 &} gt ;;
A second binder resin having a weight average molecular weight of Mw &lt; _{2 &} gt ;; a first shell portion surrounding the core portion; And
A third binder resin having a weight average molecular weight of Mw &lt; _{3 &} gt ;, and a second shell portion surrounding the first shell portion,
Wherein at least one portion selected from the group consisting of the core portion, the first shell portion and the second shell portion further comprises at least one of a colorant and wax,
Mw ₁ , Mw ₂ and Mw ₃ satisfy the following formula:
Mw ₂ &lt; Mw ₁ &lt; Mw ₃ . The method according to claim 1,
Wherein the weight average molecular weight of the first binder resin (Mw ₁₎ is 42,000 ~ 55,000, and wherein the weight average molecular weight of the second binder resin (Mw ₂₎ is 24,000 ~ 45,000, and a weight average molecular weight of said third binder resin (Mw ₃ ) Is from 55,000 to 79,000. The method according to claim 1,
Wherein the toner comprises 70 to 90 parts by weight of the first binder resin, 5 to 25 parts by weight of the second binder resin, and 1 to 6 parts by weight of the third binder resin. (S10) of adding a first binder resin dispersion liquid and a coagulant to a reactor, and then firstly raising the contents of the reactor to form a toner core portion;
(S20) forming a first shell portion surrounding the toner core portion by further adding a second binder resin dispersion to the reactor contents containing the toner core portion;
(S30) forming a second shell portion surrounding the first shell portion by further adding a third binder resin dispersion to the reactor contents containing the first shell portion; And
And a step (S40) of obtaining the combined toner particles by secondarily raising the contents of the reactor through the second shell part forming step,
At least one of the colorant dispersion and the wax dispersion is further added to the reactor in at least one of steps (S10) and (S20)
The weight average molecular weight (Mw ₁ ) of the first binder resin contained in the first binder resin dispersion, the weight average molecular weight (Mw ₂ ) of the second binder resin contained in the second binder resin dispersion, Wherein the weight average molecular weight (Mw ₃ ) of the third binder resin contained in the toner particles satisfies the following formula:
Mw ₂ < Mw ₁ < Mw ₃ . 5. The method of claim 4,
In the step (S10), wherein the first binder resin dispersion in place of the second binder resin dispersion liquid, and In the second with a second binder resin dispersion liquid in the reactor, and in this case, the Mw ₁ is of the second binder resin dispersion Wherein the Mw ₂ and the Mw ₃ are values obtained by weighted averages of Mw ₂ and Mw ₃ in accordance with the ratio of the amounts of the second binder resin and the third binder resin in the third binder resin dispersion. 5. The method of claim 4,
Wherein the primary temperature elevation progresses to a temperature 2 to 20 占 폚 lower than a glass transition temperature of the first binder resin injected into the core portion forming step. 5. The method of claim 4,
Wherein the secondary increase in temperature progresses to a temperature 10 to 40 캜 higher than a glass transition temperature of the third binder resin added to the second shell part forming step. 5. The method of claim 4,
The content of the first binder resin added to the core forming step (S10), the content of the second binder resin added to the first shell forming step (S20), and the second shell forming step (S30) Wherein the content of the third binder resin added is 70 to 90 parts by weight, 5 to 25 parts by weight and 1 to 6 parts by weight, respectively.

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